Intraoperative Real-Time Intrasaccular Pressure Monitoring: A Feasible Strategy to Optimize Coil Utilization and Individualize Flow Diverter Therapy for Unruptured Intracranial Aneurysms

Intraoperative Real-Time Intrasaccular Pressure Monitoring: A Feasible Strategy to Optimize Coil Utilization and Individualize Flow Diverter Therapy for Unruptured Intracranial Aneurysms | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Intraoperative Real-Time Intrasaccular Pressure Monitoring: A Feasible Strategy to Optimize Coil Utilization and Individualize Flow Diverter Therapy for Unruptured Intracranial Aneurysms Jianguo Zhong, Renhui Yi, Yu Jiang, Junrong Lian, Gengsheng Mao, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7969411/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Purpose This study investigates the clinical value of using flow diverter (FD) to treat patients with unruptured intracranial aneurysms (UIAs), specifically examining changes in aneurysm sac pressure and hemodynamics before and after intraoperative FD deployment to guide the need for additional coil embolization. The aim is to explore whether FD deployment sufficiently reduces aneurysm pressure, thereby minimizing or eliminating the need for coils. Methods A prospective cohort study enrolled 47 patients with UIAs undergoing FD treatment at the First Affiliated Hospital of Gannan Medical University from February 2023 to November 2024. Patients were divided into a pressure monitoring group (n = 23) and a control group (n = 24) based on whether real-time pressure monitoring was performed intraoperatively. The pressure monitoring group determined additional coil embolization based on changes in aneurysm sac pressure before and after FD deployment; the control group followed conventional experience-based procedures. Clinical characteristics, intraoperative parameters, coil packing density, and follow-up outcomes were compared between groups. The relationship between the dome-to-neck ratio ratio (DNR) and pressure changes was analyzed. Results Following FD deployment, the intra-aneurysmal systolic pressure (ISP) decreased by 11.8% ( P = 0.041) in the pressure monitoring group, and the Intra-Aneurysmal Pressure (IAP) / Mean Arterial Pressure (MAP) ratio decreased by 5.56% ( P = 0.019). DNR was significantly higher in the pressure-increase subgroup than in the decrease subgroup (1.47 ± 0.51 vs. 0.98 ± 0.32, P < 0.001) and positively correlated with ΔIAP/ΔMAP ( r = 0.69, P 1.47 predicts increased intravascular pressure. The combination of pressure monitoring and coils reduced the rate of coiling by 19.4% compared to the control group, with significantly lower filling density (7.23% ± 1.37% vs. 17.89% ± 2.00%, P = 0.001). Follow-up showed no statistically significant differences between groups in occlusion rates or outcomes (mRS ≤ 1). Conclusion Intraoperative real-time pressure monitoring safely and effectively guides coil embolization during FD deployment for UIA. A DNR > 1.47 indicates increased risk of intraluminal pressure rise after FD deployment; such patients require supplemental coils embolization to achieve a filling density of approximately 7.23% for pressure stabilization. This strategy helps reduce coil consumption and optimize individualized treatment plans. Health sciences/Diseases Health sciences/Medical research Health sciences/Neurology Flow diversion Unruptured intracranial aneurysm Intraoperative pressure monitoring dome-to-neck ratio Coils embolization Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction Intracranial aneurysms are cerebrovascular diseases that pose a serious threat to human health. Although unruptured aneurysms have an annual rupture rate of only 0.5%–2%( 1 , 2 ), once ruptured, they can cause subarachnoid hemorrhage (SAH), which is associated with high mortality and morbidity( 3 , 4 ). Traditional surgical and endovascular treatments have limited efficacy in complex or wide-necked aneurysms. Flow diverter (FD) remodel blood flow to achieve aneurysm neck endothelialization and intra-aneurysmal thrombosis( 5 ), significantly improving the occlusion rate of unruptured intracranial aneurysms (UIAs)( 6 , 7 ). However, hemorrhagic complications such as delayed aneurysm rupture (DAR) after FD placement, despite having a relatively low incidence (3%–11%)( 8 ), have a mortality rate as high as 70%–80%( 5 , 9 ). The mechanism underlying DAR is believed to be related to intra-aneurysmal pressure elevation( 10 ). Some researchers have conducted further studies on intra-aneurysmal hemodynamics using computational fluid dynamics (CFD)( 11 ). Nevertheless, while CFD models can simulate changes in blood flow patterns after FD deployment, their accuracy is highly dependent on the setting of boundary conditions, and they struggle to capture transient intraoperative hemodynamic states( 12 ). Notably, most current studies focus on endpoint indicators such as long-term occlusion rates, and there is a lack of systematic research on immediate hemodynamic responses after FD deployment (e.g., intra-aneurysmal pressure oscillations, transient changes in wall shear stress)( 13 , 14 ). This "black-box" evaluation model not only limits in-depth clinical understanding of the mechanisms underlying complications but also hinders the optimization of individualized treatment strategies. In addition, numerous studies on FD treatment of UIAs have confirmed that both standalone FD therapy and FD combined with coil embolization achieve high aneurysm occlusion rates( 6 , 7 ). However, further investigation into whether FD combined with coil embolization can reduce the incidence of delayed rupture is lacking. Currently, there is no unified standard for determining whether to combine coil embolization during FD treatment of UIAs, leading to significant variations in clinical practice. In the U.S. PUFs study, FD combined with coil embolization accounted for 0.9% (1/109) of cases, with a DAR incidence of 5.6%( 7 ); in the global multicenter ASPIRe study (involving 28 centers across the U.S., Europe, and Canada), this combination therapy accounted for 17.3% (33/191) of cases, with a DAR incidence of 6.8%( 15 ). In contrast, the large-scale Chinese multicenter PLUs study reported a much higher proportion of FD combined with coil embolization (48.3%, 637/1322), with an incidence of hemorrhagic complications of 4% (47/1171)( 6 ). Based on cases of DAR caused by intra-aneurysmal pressure elevation after FD deployment, combined with differences in FD utilization between China and Europe/North America, it can be concluded that there is considerable controversy regarding the "necessity of coil packing" and "optimization of packing density" in FD application, and no clear guidelines have been established to guide coil use( 7 ). In China, most physicians perform coil packing based on their clinical experience. This study aims to address the limitations of existing research by guiding coil packing through intraoperative real-time pressure monitoring and analyzing the patterns of intra-aneurysmal pressure changes before and after FD deployment. Building on current research, we hypothesize that dynamic changes in intra-aneurysmal pressure after FD implantation can serve as a key indicator for predicting DAR risk, and coil packing may optimize treatment outcomes by reducing the magnitude of intra-aneurysmal pressure fluctuations. This exploration is expected not only to uncover the pathological mechanism of DAR but also to provide quantitative criteria for optimizing the indications of FD combined with coil embolization, ultimately achieving the clinical goals of reducing complication risks and improving patient prognosis. 2. Methods 2.1 Study Design This study was a prospective cohort study conducted from February 2023 to November 2024, with the ethical approval number: LLSC2023-171. All study methods were performed in accordance with the ethical principles of the Declaration of Helsinki (adopted in 1964 and revised in subsequent updates) and relevant national regulations on medical research involving human subjects in China. Grouping: Pressure Monitoring Group (guided by real-time pressure) vs. Control Group (treated with conventional therapy). (Fig. 1 ) 2.2 Patient Selection Inclusion Criteria: ( 1 ) Diagnosis of saccular unruptured intracranial aneurysms (UIAs) confirmed by computed tomography angiography (CTA), magnetic resonance angiography (MRA), or digital subtraction angiography (DSA);( 2 ) No branch vessels originating from the aneurysm dome or neck;( 3 ) Age > 18 years;( 4 ) Estimated survival time of no less than 3 months;( 5 ) Basically normal liver, kidney, heart, and lung function;( 6 ) No obvious active infection;( 7 ) Informed consent signed by the patient or their legal/authorized representative;( 8 ) Physically fit to tolerate surgery, and planned to undergo either standalone flow diverter (FD) therapy or FD combined with coil embolization. Exclusion Criteria: ( 1 ) Comorbidity with other cerebrovascular diseases that cause a complex hemodynamic environment (e.g., arteriovenous malformations, arteriovenous fistulas, Moyamoya disease); ( 2 ) DSA findings indicating non-saccular aneurysms, such as dissecting aneurysms, fusiform aneurysms, pseudoaneurysms, and traumatic aneurysms; ( 3 ) Patients lost to follow-up. Grouping Basis: Patients were divided into the pressure monitoring group (experimental group) and the control group based on whether real-time pressure monitoring was performed before and after intraoperative FD deployment. For the pressure monitoring group: The decision to perform coil packing was determined by intra-aneurysmal pressure changes after FD deployment. If the intrasaccular pressure decreased after FD placement, no coils were used; if the pressure increased, coils were packed until the pressure decreased or stabilized, after which packing was stopped. For the control group: Conventional FD therapy was administered for UIAs, and the decision to combine coil embolization (or not) was based on previous clinical experience. Additionally, to further investigate intrasaccular pressure changes after FD placement, patients in the pressure monitoring group were subdivided into a pressure increase subgroup and a pressure decrease subgroup, according to whether the intrasaccular pressure increased or decreased after FD deployment. 2.3 Pressure Monitoring Technique 2.3.1 Microcatheter verification This study evaluated the accuracy of Echelon 10 microcatheter pressure measurements when using an in vitro silicone vascular model (Medtronic, Inc., USA) to simulate intracranial vascular anatomy (Fig. 2 ). The Echelon 10 microcatheter and a high-precision pressure guidewire (C12059, Abbott, USA) were placed in the same measurement position in the vascular model. Graded pressure signals were generated by precisely adjusting the saline infusion rate. Pearson's correlation coefficient analysis was used to assess the agreement between these two pressure measurements. 2.3.2 operation technique All patients underwent general anesthesia, and bilateral femoral arteries were punctured using the Seldinger technique( 16 ). An 8F arterial sheath was placed on one side, and a 5F arterial sheath on the other. After systemic heparinization, an 8F introducer catheter supported by a 5F intermediate catheter was advanced to the predetermined position via the 8F arterial sheath under the guidance of a loach guidewire. Subsequently, the 5F intermediate catheter was positioned in the internal carotid artery proximal to the intracranial aneurysm, with continuous and slow intravenous infusion of heparinized saline throughout the procedure. On the contralateral side, via the 5F arterial sheath and under the guidance of a loach guidewire, a 5F introducer catheter was placed in the internal carotid artery proximal to the intracranial aneurysm, on the same side as the 8F introducer catheter. Three-dimensional reconstructed angiography was performed on the target-side internal carotid artery to measure the diameters of the parent artery at the distal and proximal ends of the aneurysm; an appropriately sized FD was selected based on these measurements. Meanwhile, the length of the aneurysm neck and the maximum diameter of the aneurysm dome were recorded. Systolic blood pressure was maintained at 110–120 mmHg and stabilized, and arterial blood pressure was recorded once stabilized. Under the guidance of a microfilament, an Echelon 10 microcatheter (ev3 Neuro-vascular, Irvine, USA) was advanced through the 5F introducer catheter into the mid-region of the aneurysm sac. A disposable pressure transducer was connected to the distal end of the microcatheter to record the initial intrasaccular pressure (Figure S3), and the Echelon 10 microcatheter was kept in an appropriate position within the aneurysm sac. Under roadmap guidance, an FD stent microcatheter was introduced through the 5F intermediate catheter and positioned across the aneurysm. The FD was loaded into the microcatheter and gradually deployed starting from the distal end of the aneurysm, ensuring the aneurysm neck was within the effective working length of the FD. After complete deployment, stent massage was performed as needed to assist in stent expansion and optimal wall apposition. Three-dimensional high-precision reconstructed imaging of the stent was conducted to assess FD wall apposition. Following stent stabilization, the pressure data from the Echelon 10 microcatheter transducer and arterial blood pressure were recorded again to collect pressure parameters (Table S1). The need for coil embolization was evaluated based on intrasaccular pressure changes after FD deployment: if pressure decreased, no coils were used; if intrasaccular pressure increased, coils were deployed until the pressure decreased or stabilized. Subsequently, all catheters were withdrawn, and the femoral artery puncture sites were sealed using a vascular sealer. All procedures were performed by the same neurointerventionalist with more than 15 years of interventional experience. 2.4 Data Analysis Data normality was assessed using the Shapiro-Wilk test, and continuous variables that conformed to normal distribution were expressed as mean ± standard deviation, and comparisons between groups were made using the independent samples t test; non-normally distributed data were expressed as median (interquartile spacing), and comparisons between groups were made using the Mann-Whitney U test. Categorical variables (e.g., gender, type of complication) were analyzed by chi-square test or Fisher's exact test. The correlation between pressure change indicators and the number of spring coils was analyzed by Pearson's correlation coefficient, and the subgroup analysis classified the patients in the manometry group into pressure rise subgroups and pressure fall subgroups according to the rise and fall of pressure after FD placement, and the differences in morphological parameters were compared using the t test for independent samples. A linear regression model was constructed to investigate the effect of body to neck ratio and other factors on ΔIAP/ΔMAP. The differences were analyzed using IBM SPSS Statistics 26.0, and P < 0.05 was considered significant. 3. Results 3.1. Patient and Aneurysm Characteristics Pipeline Embolization Device (PED)—a commonly used type of FD—were successfully deployed in all 47 patients, achieving a 100% technical success rate, and there were no significant differences between the pressure monitoring group (n = 23) and the control group (n = 24) in terms of the following indicators (Table 1 ) : demographic characteristics, ages of (59.8 ± 9.0) and (55.8 ± 7.9) years ( P = 0.110), and the proportion of females was 82.6% and 79.2% ( P = 0.764), respectively. In terms of aneurysm morphology, the median aneurysm diameters were 7.16 mm and 5.28 mm ( P = 0.148), and the median DNR were 1.27 and 1.40 ( P = 0.983), respectively (Table 2 ). The baseline confounders were comparable between the two groups, ensuring the validity of hemodynamic comparisons. Table 1 Baseline Clinical Data: Pressure vs. Control Groups Clinical Characteristics Pressure Monitoring Group( n = 23) Control Group( n = 24) Test Statistic ( t /χ²) P Value Gender (Male) 4(17.39%) 5(20.83%) 0.090 0.764 Age (Years) 59.78 ± 9.03 55.75 ± 7.90 1.633 0.110 Hypertension 15(65.22%) 8(33.33%) 4.778 0.029 * Diabetes Mellitus 1(4.35%) 2(8.33%) 0.312 0.576 Hyperlipidemia 1(4.35%) 1(4.27%) 0.001 0.975 Smoking History 0(0.0%) 3(12.50%) 3.071 0.080 Alcohol Consumption History 0(0.0%) 3(12.50%) 3.071 0.080 mRS Score ≤ 1 on Admission 22(95.65%) 23(95.83%) 0.001 0.975 *Note: Data are presented as mean ± standard deviation (SD) for continuous variables and n (%) for categorical variables. Continuous variables were compared using independent-samples t -test, and categorical variables using chi-square ( χ ²) test. * P < 0.05 indicates statistical significance. Table 2 Intergroup Differences in Aneurysm Characteristics: Pressure Monitoring Group vs. Control Group Aneurysm Characteristics Pressure Monitoring Group ( n = 24) (Patients: n = 23) Control Group ( n = 24) (Patients: n = 24) Test Statistic (χ²/ Z / t ) P Value Number of Aneurysms (n) 23 27 — — Aneurysm Location (n, %) • ICA, C4 Segment 1(4.34%) 2(7.40%) — — • ICA, C5 Segment 4(17.39%) 9(33.33%) — — • ICA, C6 Segment 13(56.52%) 12(44.44%) — — • ICA, C7 Segment 5(21.74%) 4(18.81%) — — Regular Aneurysm Morphology (n, %) 23(1.00%) 25(92.59%) 1.775 0.183 Aneurysm Size •Maximum Dome Diameter (mm) 7.16(4.50, 10.68) 5.28(3.43, 10.09) -1.447 0.148 • Neck Diameter (mm) 5.99 ± 2.95 4.62 ± 1.85 1.921 0.061 • DNR 1.14(1.06, 1.36) 1.40 (1.00, 1.86) -1.501 0.133 *Note: 1. Data are presented as median (interquartile range, IQR) or mean ± standard deviation (SD) for continuous variables, and n (%) for categorical variables. 2. Chi-square test was not performed for aneurysm location due to small sample size in each anatomical segment. 3. Regular aneurysm morphology was analyzed using Fisher’s exact test; neck diameter was compared using independent-samples t-test; maximum dome diameter and DNR were analyzed using Mann-Whitney U test. 4. * P < 0.05 indicates statistical significance (no significant differences observed in this table). 3.2. Validation of Microcatheter-Based Pressure Monitoring Validation of microcatheter-based pressure monitoring (Fig. 3 ) showed that measurements obtained via the Echelon 10 microcatheter exhibited a strong positive correlation with pressure guidewire measurements, with a Pearson correlation coefficient of r = 1.000 ( P < 0.001); the regression equation was determined as P wire = − 0.69 + 1.34×P microcatheter (slope: 1.34; 95% confidence interval [CI] : 1.26–1.42). The technical feasibility of real-time intrasaccular pressure monitoring during PED deployment was established by this. 3.3. Pressure Changes After PED Deployment In the pressure monitoring group (n = 23), PED deployment significantly reduced the following hemodynamic parameters (Table 3 ): Intrasaccular systolic pressure (ISP): Decreased by 11.8%, from 76.0 mmHg to 67.0 mmHg ( P = 0.041); Pressure ratios: ISP/systolic blood pressure (SBP) decreased by 6.25%, from 0.64 ± 0.14 to 0.60 ± 0.13 ( P = 0.041); IAP/MAP decreased by 5.56%, from 0.90 ± 0.16 to 0.85 ± 0.16 ( P = 0.019). In most cases, PED monotherapy achieved favorable hemodynamic changes, which confirms the core flow diversion mechanism that underpins PED-based treatment for UIAs. Table 3 Pressure Changes: Pre- vs. Post-PED Deployment in the Pressure Monitoring Group Pressure Indicator Pre-PED Deployment Pre-PED Deployment Test Statistic ( t / Z ) P Value SBP (mmHg) 124.35 ± 19.07 120.91 ± 19.50 1.104 0.281 DBP (mmHg) 67.65 ± 10.22 67.35 ± 10.95 0.176 0.862 MAP (mmHg) 82.43 ± 10.37 81.13 ± 11.42 0.661 0.516 ISP (mmHg) 76.00 (65.00, 95.00) 67.00 (56.00, 91.00) -2.040 0.041* IDP (mmHg) 69.43 ± 13.31 65.22 ± 15.91 1.614 0.121 IAP (mmHg) 74.00 ± 14.00 69.48 ± 17.36 1.706 0.102 ISP/SBP Ratio 0.64 ± 0.14 0.60 ± 0.13 2.171 0.041* IDP/DBP Ratio 0.97 (0.87,1.12) 0.91 (0.81,1.11) -2.227 0.026* IAP/MAP Ratio 0.90 ± 0.16 0.85 ± 0.16 2.541 0.019* *Note: 1. Data are presented as mean ± standard deviation (SD) for normally distributed variables and median (interquartile range, IQR) for non-normally distributed variables (sample size of the Pressure Monitoring Group: n = 23). 2. Paired t-test was used for normally distributed variables, including systemic arterial pressure parameters (SBP, DBP, MAP), intra-aneurysmal diastolic pressure (IDP), and intra-aneurysmal mean pressure (IAP). Wilcoxon signed-rank test (denoted by Z statistic) was used for non-normally distributed variables, including intra-aneurysmal systolic pressure (ISP), ISP/SBP ratio, IDP/DBP ratio, and IAP/MAP ratio. 3. P 1.47 Predicts Post-PED Pressure Rise The pressure-increase subgroup (n = 8) within the pressure monitoring group had a significantly higher DNR than the pressure-decrease subgroup (Table 4 ). Linear regression analysis (Fig. 4 ) confirmed that DNR could predict ΔIAP/ΔMAP, with the regression equation: ΔIAP/ΔMAP = − 0.25 + 0.17×DNR (Pearson correlation coefficient r = 0.69, P < 0.001). This finding enables the identification of aneurysms requiring adjunctive coil embolization based on morphological features (i.e., DNR). Table 4 Inter-Subgroup Differences in DNR and Its Correlation with Hemodynamic Pressure Changes Variable Pressure Increase Subgroup ( n = 8) Pressure Decrease Subgroup ( n = 15) Statistical Test Correlation Analysis ( r / P ) DNR (Mean ± SD) 1.47 ± 0.51 0.98 ± 0.32 t = 4.57, P < 0.001 — Linear Regression: DNR vs. ΔIAP/ΔMAP — — — r = 0.69 • Slope — — — 0.17 • Intercept — — — -0.25 Notes: 1. DNR is defined as the ratio of the aneurysm’s maximum dome diameter to its neck width. 2. Inter-subgroup comparison of DNR used the independent-samples t-test; P < 0.001 indicates an extremely significant statistical difference. 3. Linear regression analysis demonstrated a significant positive correlation between DNR and ΔIAP/ΔMAP (change in intra-aneurysmal mean pressure relative to mean arterial pressure), whereΔIAP/ΔMAP is dimensionless. 3.5. Coiling Optimization Guided by Real-Time Pressure In terms of coil utilization and packing density: A reduction in the rate of FD combined with coil embolization was observed: the rate was 34.8% in the pressure monitoring group, whereas it reached 54.2% in the control group—representing a 19.4% relative reduction compared with the control group (P = 0.116) (Table 5 ). Coil packing density was significantly lower in the pressure monitoring group: the mean density was 7.23%±1.37%, as opposed to 17.89%±2.00% in the conventional control group. This translated to a statistically significant relative reduction of 10.66% in packing density between the two groups (P = 0.001) (Table 5 ). In summary, intraoperative real-time pressure monitoring not only enabled a reduction in coil usage but also ensured hemodynamic stability throughout the procedure—validating the value of pressure guidance in optimizing coil-related treatment strategies. Table 5 Inter-Group Comparison of Coil Packing Density in Patients Undergoing FD Combined with Coil Embolization Parameter Pressure Monitoring Group (FD + Coils) Control Group (FD + Coils) Test Statistic ( t ) P Value Sample Size ( n ) 8 (34.8%) 13 (54.2%) 2.467 0.116 Coil Packing Density 7.23%±1.37% 17.89%±2.00% -4.070 0.001 ** Notes: 1. The percentages in parentheses (34.8% for the Pressure Monitoring Group, 54.2% for the Control Group) represent the proportion of patients receiving FD combined with coil embolization within each group. 2. Data presentation: Sample size is expressed as n (%); coil packing density is expressed as mean ± SD. 3. Inter-group comparisons were performed using the independent-samples t -test. 4. Statistical significance: * P < 0.05, ** P < 0.01; consistent with the manuscript’s statistical criteria. 3.6. Safety and Short-Term Outcomes Intraoperative pressure monitoring did not elevate procedural risk or impair therapeutic efficacy. At a median follow-up duration of 4.5 months, no significant differences were observed between the two groups in terms of complication incidence or neurological prognosis (assessed by mRS score, with mRS ≤ 1 as a favorable outcome). (Table 6 ) Table 6 Perioperative and Postoperative Outcomes: Pressure Monitoring Group vs. Control Group Outcome Parameter Pressure Monitoring Group ( n = 23) Control Group ( n = 24) Test Statistic ( t / Z ) P Value Operative Time (min) 126.96 ± 39.48 137.92 ± 52.30 -0.808 0.423 Postoperative Hospital Stay (Days) 4.00(3.00,7.00) 5.00(3.00,6.75) -0.205 0.838 Immediate Postoperative Angiography • Aneurysm Sac Opacification¹ 19 (82.6%) 18 (75%) 0.406 0.524 • Aneurysm Neck Opacification² 4 (17.4%) 6 (25%) • Complete Occlusion³ 0 0 Notes: 1. Normally distributed continuous variables (operative time) are expressed as Mean ± SD, compared using the independent-samples t -test; Non-normally distributed continuous variables (postoperative hospital stay) are expressed as median (interquartile range, IQR), compared using the Mann-Whitney U-test ( Z -value denotes the test statistic); 2. Angiography opacification grades are defined by the O’Kelly-Marotta (OKM) scale: ¹OKM Grade A/B (aneurysm sac opacification); ²OKM Grade C (aneurysm neck opacification); ³OKM Grade D (complete occlusion). 3. No statistically significant differences were observed between groups for all outcomes ( P > 0.05) 4. Discussion​​ FD, featuring a flexible mesh structure with high metal coverage, have thoroughly revolutionized the endovascular treatment concept for UIAs by remodeling the hemodynamics of the parent artery, inducing intra-aneurysmal thrombosis, and promoting aneurysm neck endothelialization. Particularly for complex aneurysms that are difficult to treat with traditional embolization, the mid-term complete occlusion rate can reach 75%–93.4%( 1 , 2 , 5 ). Its original design intent was to reduce unnecessary intrasaccular manipulation and thereby lower the risk of rupture. However, in clinical practice, there are significant global discrepancies regarding "whether to combine FD with coil embolization": the proportion of combined therapy was merely 0.9% (1/109) in the U.S. PUFs study( 7 ), 17.3% (33/191) in the global multicenter ASPIRe study( 15 ), and as high as 48.3% (637/1322) in the large-scale Chinese multicenter PLUs study( 6 ). This discrepancy essentially arises from the lack of evidence-based basis for "the necessity of coil packing" and "the optimization of packing density"—while both standalone FD therapy and combined therapy can achieve satisfactory occlusion rates( 6 ), over-embolization increases procedural risks, and insufficient embolization may raise the risk of delayed aneurysm rupture (DAR). This contradiction urgently needs to be resolved. As the most fatal complication after FD deplayment, DAR has an incidence of only 3%–5%( 17 , 18 ) but a mortality rate as high as 70%–80%( 5 , 9 ). Its core trigger is believed to be intrasaccular hemodynamic disturbances following FD deployment, particularly pressure elevation( 19 , 20 ). An analysis of 60 DAR cases by Hou et al. confirmed that patients with DAR exhibited a significant increase in intra-aneurysmal pressure after FD deplayment( 21 ); further studies using computational fluid dynamics (CFD) by Cebral et al. revealed that sustained intra-aneurysmal pressure elevation was observed in all 3 cases of rupture after FD treatment, while no such phenomenon was noted in 4 successfully treated cases( 22 ). However, CFD technology has inherent limitations: its accuracy is highly dependent on the setting of boundary conditions, and it cannot capture transient intraoperative hemodynamic states( 23 ). This also prompted the 2024 Chinese Clinical Management Guidelines for UIAs to explicitly state: "Individualized hemodynamic analysis is still in the research phase, and it is not recommended for guiding clinical decisions at present"( 24 ). Previous attempts at pressure monitoring (e.g., dual-sensor wires) are difficult to popularize due to the risk of inducing aneurysm rupture from their rigid tips( 25 )—obtaining real-time, safe intra-aneurysmal pressure data has become the key to breaking the bottleneck in FD therapy. This study innovatively developed a dual-validation pressure monitoring system integrating the "Echelon 10 microcatheter and pressure guidewire". Validated using an in vitro silicone vascular model, the measurements from the Echelon 10 microcatheter exhibited an extremely strong positive correlation with those from a high-precision pressure guidewire (Model C12059, Abbott) (Pearson correlation coefficient r = 0.98–1.000, P < 0.001). A regression equation was established as follows: P wire = − 0.69 + 1.34×P microcatheter (95% confidence interval [CI] for the slope: 1.26–1.42). This system fully addresses the limitations of traditional pressure monitoring techniques: on one hand, it avoids the rupture risk associated with rigid pressure guidewires; on the other hand, through standardized normalization of "intra-aneurysmal mean pressure/systemic mean arterial pressure (IAP/MAP)", it eliminates the interference of individual blood pressure fluctuations on pressure assessment, enabling real-time and accurate intra-aneurysmal pressure monitoring during FD deployment. More importantly, all cases uniformly used the Pipeline Embolization Device (PED, a commonly utilized FD), and the procedures were performed by the same neurointerventionalist with over 15 years of interventional experience—this ensured the homogeneity and comparability of the study data. Based on this pressure monitoring system, the present study identified key hemodynamic patterns and quantitative thresholds for FD-based UIA treatment, providing core evidence for individualized therapy. First, FD deployment significantly improves the hemodynamic status of low-risk aneurysms. In the pressure monitoring group (n = 23), after FD deployment, intra-aneurysmal systolic pressure (ISP) decreased by 11.8% (from 76.0 mmHg to 67.0 mmHg, P = 0.041), and the ratio of IAP/MAP decreased by 5.56% (from 0.90 ± 0.16 to 0.85 ± 0.16, P = 0.019). Notably, the study observed a transient pressure elevation at the initial stage of FD deployment: when the distal end of the FD first covered the aneurysm neck, some cases exhibited temporary pressure rise due to "unobstructed inflow but obstructed outflow," which led to the formation of unstable small vortices inside the aneurysm sac. However, the pressure gradually declined after complete FD deployment. This finding suggests that clinicians should pay attention to dynamic pressure changes during FD deployment to avoid misjudging therapeutic efficacy based on transient fluctuations. Second, a DNR > 1.47 is a key predictive indicator for intra-aneurysmal pressure elevation after FD deployment. Subgroup analysis of the pressure monitoring group showed that the mean DNR of the pressure-increase subgroup (n = 8) was 1.47 ± 0.51, which was significantly higher than that of the pressure-decrease subgroup (0.98 ± 0.32, P < 0.001). Additionally, DNR was significantly positively correlated with ΔIAP/ΔMAP (Pearson correlation coefficient r = 0.69, P 1.47, the aneurysm exhibits a "bottle-like" configuration, making it difficult for the FD to fully cover the aneurysm neck or effectively remodel the blood flow path. This leads to continuous blood flow into the aneurysm sac and subsequent pressure elevation—this provides a mechanistic explanation for the morphological predisposing factors of DAR and is also consistent with the CFD conclusion by Cebral et al. that "aneurysms with high DNR have more complex hemodynamics"( 22 ). Based on this, the study proposes a critical threshold of DNR = 1.47: for aneurysms with DNR ≤ 1.47, FD monotherapy is sufficient to achieve pressure stability (pressure decreased in 65.2% of cases); for aneurysms with DNR > 1.47, adjunctive coil embolization is required to mitigate the risk of pressure elevation. Third, real-time pressure monitoring can significantly optimize coil utilization strategies, enabling "precision embolization". In the pressure monitoring group, the rate of FD combined with coil embolization was 34.8%, which was a 19.4% reduction compared with 54.2% in the control group. Additionally, the mean coil packing density in the pressure monitoring group was 7.23%±1.37%, representing a significant 10.66% decrease compared with 17.89%±2.00% in the control group ( P = 0.001). Further correlation analysis revealed a strong negative correlation between coil packing density and ΔIAP/ΔMAP (Pearson correlation coefficient r = − 0.900, P = 0.001). When the coil packing density reached 7.23%, ΔIAP/ΔMAP ≤ 0.1, indicating that intra-aneurysmal pressure was stabilized. This finding challenges the traditional belief that "a high packing density (> 20%) is an essential prerequisite for ensuring therapeutic efficacy"—the role of coils is not to "fill the aneurysm sac", but to stabilize intra-aneurysmal pressure by attenuating systolic pressure peaks and reducing turbulence through the dual mechanisms of "mechanical occupation to increase blood flow resistance" and "promoting thrombosis to occlude the aneurysm sac". Meanwhile, the reduction in packing density delivers significant clinical and economic value: it not only did not increase the risk of complications (perioperative complication rate: 8.70% in the pressure monitoring group versus 12.5% in the control group, P = 0.672) but also showed no differences from the control group in terms of short-term occlusion rate (78.26% in the pressure monitoring group versus 75.00% in the control group, P = 0.792) and neurological prognosis (proportion of patients with mRS score ≤ 1: >91% in both groups). This offers a new approach for the precise and cost-effective treatment of UIAs. This study still has limitations that need to be addressed in future research: First, it adopts a single-center, small-sample design (47 patients in total, 23 in the pressure monitoring group). Additionally, only internal carotid artery aneurysms were included, without covering complex subtypes such as fusiform and blister-like aneurysms—thus, caution is required when generalizing the conclusions to aneurysms in other locations or of other types. Second, intraoperative pressure monitoring focused solely on immediate changes after FD deployment, lacking long-term dynamic pressure data. This precludes the assessment of the association between pressure stability and long-term occlusion or recurrence rates. Third, from a technical perspective, the spatial resolution of the pressure sensor (± 2 mmHg) and microcatheter positioning errors may introduce measurement biases. Furthermore, the median follow-up time was only 4.5 months, which is insufficient to fully assess the long-term DAR risk beyond 30 days. Extended follow-up periods are needed to verify the long-term safety of the combined treatment strategy. In conclusion, through a dual-dimensional exploration of "real-time pressure monitoring-morphological analysis", this study established key quantitative criteria for FD-based treatment of UIAs: a DNR > 1.47 indicates a risk of intra-aneurysmal pressure elevation, requiring adjunctive coil embolization to a coil packing density of 7.23% to achieve pressure stabilization; meanwhile, pressure guidance reduces the coil usage rate by 19.4% and the coil packing density by 10.66%, optimizing treatment costs while ensuring therapeutic efficacy and safety. In the future, large-scale multicenter studies are needed not only to verify the generalizability of the DNR threshold but also to explore optimization directions for FD porosity and radial support force—with the ultimate goal of promoting intraoperative pressure-guided FD therapy to become a standard paradigm in the clinical management of UIAs 5. Conclusions Intraoperative real-time pressure monitoring exhibits favorable safety and feasibility in the treatment of UIAs using FD, and can effectively guide adjunctive coil embolization procedures. DNR > 1.47 indicates an increased risk of intra-aneurysmal pressure elevation after FD deployment; such patients require adjunctive coil embolization, and a coil packing density of approximately 7.23% is sufficient to achieve intra-aneurysmal pressure stabilization. This therapeutic strategy provides a quantitative reference basis for the individualized treatment of UIAs and holds significant clinical application value. Declarations Ethics statement This study involves human participants, and the study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Gannan Medical University (Approval No. LLSC2023-171). All patients or their legal/authorized representatives provided written informed consent to participate in this study. Additionally, written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article (e.g., intraoperative pressure monitoring images in Figure S3). Competing interests The authors have no competing interests to declare. Author Contributions Jianguo Zhong # : Conception and design of the study; acquisition, analysis, and interpretation of data; drafting the initial manuscript; and revising it for important intellectual content.Renhui Yi # : Conception and design of the study; statistical analysis of data; critical revision of the manuscript for intellectual content; and final approval of the submitted version. These two authors (Jianguo Zhong and Renhui Yi) contributed equally to this work and share co-first authorship. Yu Jiang: Acquisition of clinical data; assistance in data validation; and revision of the manuscript for clarity.Junrong Lian: Contribution to intraoperative data collection; technical support for experimental procedures; and review of the manuscript. Gengsheng Mao * : Supervision of the study design; provision of critical intellectual input; securing funding; and final approval of the manuscript.Shaochun Yang * : Overall supervision of the project; finalization of the study protocol; critical revision of the manuscript for scientific accuracy; and responsibility for the integrity of the work. Note: # indicates co-first authors; * indicates corresponding authors. Funding The study was supported by Key Research and Development Project of Ganzhou Science and Technology Department (No. 2023LNS37753); National Natural Science Foundation of China (82360599); Natural Science Foundation of Jiangxi Province (20232BAB206121). Availability of data and materials The raw data supporting the conclusions of this article (including clinical baseline data, intraoperative pressure parameters, and follow-up records) will be made available by the corresponding authors (Gengsheng Mao and Shaochun Yang) upon reasonable request, without undue reservation. Acknowledgments We extend our sincere gratitude to Professor Qiu Chuanzhen and Dr. Liu Ming from the Department of Neurosurgery at the First Affiliated Hospital of South Jiangxi Medical University for their invaluable support in this research. References Shen, D. et al. Sex disparities in the risk of intracranial aneurysm rupture: a case-control study. Front. Neurol. 15 , 1483679 (2024). Van Hoe, W. et al. Screening for Intracranial Aneurysms in Individuals with a Positive First-Degree Family History: A Systematic Review. World Neurosurg. ; 151 : (2021). 235 – 48.e5. Gu, L. et al. Global, Regional, and National Burden of Subarachnoid Hemorrhage: Trends From 1990 to 2021 and 20-Year Forecasts. Stroke 56 (4), 887–897 (2025). Thilak, S. et al. Diagnosis and management of subarachnoid haemorrhage. Nat. Commun. 15 (1), 1850 (2024). Kang, H. et al. Pipeline Embolization Device for Intracranial Aneurysms in a Large Chinese Cohort: Complication Risk Factor Analysis. Neurotherapeutics 18 (2), 1198–1206 (2021). Luo, B. et al. Pipeline Embolization device for intracranial aneurysms in a large Chinese cohort: factors related to aneurysm occlusion. Ther. Adv. Neurol. Disord . 13 , 1756286420967828 (2020). Becske, T. et al. Long-Term Clinical and Angiographic Outcomes Following Pipeline Embolization Device Treatment of Complex Internal Carotid Artery Aneurysms: Five-Year Results of the Pipeline for Uncoilable or Failed Aneurysms Trial. Neurosurgery 80 (1), 40–48 (2017). [Chinese guideline for the. clinical management of patients with unruptured intracranial aneurysms (2024)]. Zhonghua Yi Xue Za Zhi . 104 (21), 1918–1939 (2024). Tsukagoshi, E., Sato, H. & Kohyama, S. Delayed aneurysm rupture in a patient treated with flow redirection endoluminal device: A case report and literature review. Surg. Neurol. Int. 13 , 506 (2022). Shobayashi, Y. et al. Intra-aneurysmal hemodynamic alterations by a self-expandable intracranial stent and flow diversion stent: high intra-aneurysmal pressure remains regardless of flow velocity reduction. J. Neurointerv Surg. 5 (Suppl 3), iii38–42 (2013). Rahma, A. G. & Abdelhamid, T. Hemodynamic and fluid flow analysis of a cerebral aneurysm: a CFD simulation. SN Appl. Sci. 5 (2), 62 (2023). Shimano, K. et al. Understanding of boundary conditions imposed at multiple outlets in computational haemodynamic analysis of cerebral aneurysm. J. Biorheol. 33 (2), 32–42 (2019). Boniforti, M. A., Magini, R. & Orosco Salinas, T. Hemodynamic Investigation of the Flow Diverter Treatment of Intracranial Aneurysm. Fluids 8 (7), 189 (2023). Thormann, M. et al. Computational Flow Diverter Implantation—A Comparative Study on Pre-Interventional Simulation and Post-Interventional Device Positioning for a Novel Blood Flow Modulator. Fluids 9 (3), 55 (2024). Kallmes, D. F. et al. Aneurysm Study of Pipeline in an Observational Registry (ASPIRe). Interv Neurol. 5 (1–2), 89–99 (2016). Seldinger, S. I. Catheter replacement of the needle in percutaneous arteriography. A new technique. Acta Radiol. Suppl. (Stockholm) . 434 , 47–52 (2008). Rouchaud, A. et al. Delayed hemorrhagic complications after flow diversion for intracranial aneurysms: a literature overview. Neuroradiology 58 (2), 171–177 (2016). Brinjikji, W. et al. Risk Factors for Ischemic Complications following Pipeline Embolization Device Treatment of Intracranial Aneurysms: Results from the IntrePED Study. AJNR Am. J. Neuroradiol. 37 (9), 1673–1678 (2016). Claassen, J., Thijssen, D. H. J., Panerai, R. B. & Faraci, F. M. Regulation of cerebral blood flow in humans: physiology and clinical implications of autoregulation. Physiol. Rev. 101 (4), 1487–1559 (2021). Colby, G. P. et al. Immediate procedural outcomes in 44 consecutive Pipeline Flex cases: the first North American single-center series. J. Neurointerv Surg. 8 (7), 702–709 (2016). Hou, K. et al. Delayed rupture of intracranial aneurysms after placement of intra-luminal flow diverter. Neuroradiol. J. 33 (6), 451–464 (2020). Cebral, J. R. et al. Aneurysm rupture following treatment with flow-diverting stents: computational hemodynamics analysis of treatment. AJNR Am. J. Neuroradiol. 32 (1), 27–33 (2011). Huang, Q. et al. Hemodynamic changes by flow diverters in rabbit aneurysm models: a computational fluid dynamic study based on micro-computed tomography reconstruction. Stroke 44 (7), 1936–1941 (2013). Dinger, T. F. et al. Patients' Characteristics Associated With Size of Ruptured and Unruptured Intracranial Aneurysms. Brain Behav. 14 (11), e70161 (2024). Schneiders, J. J., VanBavel, E., Majoie, C. B., Ferns, S. P. & van den Berg, R. A flow-diverting stent is not a pressure-diverting stent. AJNR Am. J. Neuroradiol. 34 (1), E1–4 (2013). Additional Declarations No competing interests reported. Supplementary Files TableS1Relevantpressureparametersutilizedinthisstudy.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 04 Dec, 2025 Reviews received at journal 03 Dec, 2025 Reviews received at journal 24 Nov, 2025 Reviewers agreed at journal 21 Nov, 2025 Reviewers agreed at journal 20 Nov, 2025 Reviewers agreed at journal 19 Nov, 2025 Reviewers invited by journal 18 Nov, 2025 Editor assigned by journal 18 Nov, 2025 Editor invited by journal 04 Nov, 2025 Submission checks completed at journal 31 Oct, 2025 First submitted to journal 31 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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1","display":"","copyAsset":false,"role":"figure","size":279301,"visible":true,"origin":"","legend":"\u003cp\u003eLiterature Selection Process\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-7969411/v1/7d51b24375cac7e768e887b5.png"},{"id":95224169,"identity":"0cd3ae62-9b62-4f49-a75c-c756ff72797b","added_by":"auto","created_at":"2025-11-05 16:23:28","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":902569,"visible":true,"origin":"","legend":"\u003cp\u003eA: Coaxial positioning of the Echelon™ 10 microcatheter and pressure-sensing wire within the same vessel segment;B: In vitro silicone vascular model;C: Pressure measurements obtained via pressure-sensing wire;D: Pressure measurements acquired through the Echelon™ 10 microcatheter.\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-7969411/v1/fb2cd045c1a3224963332bf4.png"},{"id":95224539,"identity":"adc3dc8e-2543-459d-a22e-f8825aa2974d","added_by":"auto","created_at":"2025-11-05 16:23:52","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":491485,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation between microcatheter and pressure guidewire pressure measurements.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-7969411/v1/41c9e09000034635a560efd2.png"},{"id":95104147,"identity":"b62a9f7f-ef5a-4dc0-92f7-4ddb88b73f32","added_by":"auto","created_at":"2025-11-04 10:26:09","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":639294,"visible":true,"origin":"","legend":"\u003cp\u003eLinear regression analysis of dome-to-neck ratio (DNR) and the ratio of intra-aneurysmal pressure change to mean arterial pressure change (ΔIAP/ΔMAP).\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-7969411/v1/1674ba6acd984c1d9dd92d30.png"},{"id":95230261,"identity":"bb9bf455-7214-448f-8cb2-64c52f706e36","added_by":"auto","created_at":"2025-11-05 16:37:05","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3491638,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7969411/v1/1f60e049-9c1d-4070-a1a3-18fc79f31f06.pdf"},{"id":95104135,"identity":"00170a2a-a9d6-4bbd-bee7-ec423095bba5","added_by":"auto","created_at":"2025-11-04 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Introduction","content":"\u003cp\u003eIntracranial aneurysms are cerebrovascular diseases that pose a serious threat to human health. Although unruptured aneurysms have an annual rupture rate of only 0.5%\u0026ndash;2%(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e), once ruptured, they can cause subarachnoid hemorrhage (SAH), which is associated with high mortality and morbidity(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Traditional surgical and endovascular treatments have limited efficacy in complex or wide-necked aneurysms. Flow diverter (FD) remodel blood flow to achieve aneurysm neck endothelialization and intra-aneurysmal thrombosis(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e), significantly improving the occlusion rate of unruptured intracranial aneurysms (UIAs)(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). However, hemorrhagic complications such as delayed aneurysm rupture (DAR) after FD placement, despite having a relatively low incidence (3%\u0026ndash;11%)(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e), have a mortality rate as high as 70%\u0026ndash;80%(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). The mechanism underlying DAR is believed to be related to intra-aneurysmal pressure elevation(\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Some researchers have conducted further studies on intra-aneurysmal hemodynamics using computational fluid dynamics (CFD)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). Nevertheless, while CFD models can simulate changes in blood flow patterns after FD deployment, their accuracy is highly dependent on the setting of boundary conditions, and they struggle to capture transient intraoperative hemodynamic states(\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Notably, most current studies focus on endpoint indicators such as long-term occlusion rates, and there is a lack of systematic research on immediate hemodynamic responses after FD deployment (e.g., intra-aneurysmal pressure oscillations, transient changes in wall shear stress)(\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). This \"black-box\" evaluation model not only limits in-depth clinical understanding of the mechanisms underlying complications but also hinders the optimization of individualized treatment strategies.\u003c/p\u003e\u003cp\u003eIn addition, numerous studies on FD treatment of UIAs have confirmed that both standalone FD therapy and FD combined with coil embolization achieve high aneurysm occlusion rates(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). However, further investigation into whether FD combined with coil embolization can reduce the incidence of delayed rupture is lacking. Currently, there is no unified standard for determining whether to combine coil embolization during FD treatment of UIAs, leading to significant variations in clinical practice. In the U.S. PUFs study, FD combined with coil embolization accounted for 0.9% (1/109) of cases, with a DAR incidence of 5.6%(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e); in the global multicenter ASPIRe study (involving 28 centers across the U.S., Europe, and Canada), this combination therapy accounted for 17.3% (33/191) of cases, with a DAR incidence of 6.8%(\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). In contrast, the large-scale Chinese multicenter PLUs study reported a much higher proportion of FD combined with coil embolization (48.3%, 637/1322), with an incidence of hemorrhagic complications of 4% (47/1171)(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Based on cases of DAR caused by intra-aneurysmal pressure elevation after FD deployment, combined with differences in FD utilization between China and Europe/North America, it can be concluded that there is considerable controversy regarding the \"necessity of coil packing\" and \"optimization of packing density\" in FD application, and no clear guidelines have been established to guide coil use(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). In China, most physicians perform coil packing based on their clinical experience.\u003c/p\u003e\u003cp\u003eThis study aims to address the limitations of existing research by guiding coil packing through intraoperative real-time pressure monitoring and analyzing the patterns of intra-aneurysmal pressure changes before and after FD deployment. Building on current research, we hypothesize that dynamic changes in intra-aneurysmal pressure after FD implantation can serve as a key indicator for predicting DAR risk, and coil packing may optimize treatment outcomes by reducing the magnitude of intra-aneurysmal pressure fluctuations. This exploration is expected not only to uncover the pathological mechanism of DAR but also to provide quantitative criteria for optimizing the indications of FD combined with coil embolization, ultimately achieving the clinical goals of reducing complication risks and improving patient prognosis.\u003c/p\u003e"},{"header":"2. Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Study Design\u003c/h2\u003e\u003cp\u003eThis study was a prospective cohort study conducted from February 2023 to November 2024, with the ethical approval number: LLSC2023-171. All study methods were performed in accordance with the ethical principles of the Declaration of Helsinki (adopted in 1964 and revised in subsequent updates) and relevant national regulations on medical research involving human subjects in China. Grouping: Pressure Monitoring Group (guided by real-time pressure) vs. Control Group (treated with conventional therapy). (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e)\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Patient Selection\u003c/h2\u003e\u003cp\u003eInclusion Criteria: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) Diagnosis of saccular unruptured intracranial aneurysms (UIAs) confirmed by computed tomography angiography (CTA), magnetic resonance angiography (MRA), or digital subtraction angiography (DSA);(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) No branch vessels originating from the aneurysm dome or neck;(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) Age\u0026thinsp;\u0026gt;\u0026thinsp;18 years;(\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) Estimated survival time of no less than 3 months;(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) Basically normal liver, kidney, heart, and lung function;(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e) No obvious active infection;(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e) Informed consent signed by the patient or their legal/authorized representative;(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e) Physically fit to tolerate surgery, and planned to undergo either standalone flow diverter (FD) therapy or FD combined with coil embolization.\u003c/p\u003e\u003cp\u003eExclusion Criteria: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) Comorbidity with other cerebrovascular diseases that cause a complex hemodynamic environment (e.g., arteriovenous malformations, arteriovenous fistulas, Moyamoya disease); (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) DSA findings indicating non-saccular aneurysms, such as dissecting aneurysms, fusiform aneurysms, pseudoaneurysms, and traumatic aneurysms; (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) Patients lost to follow-up.\u003c/p\u003e\u003cp\u003eGrouping Basis: Patients were divided into the pressure monitoring group (experimental group) and the control group based on whether real-time pressure monitoring was performed before and after intraoperative FD deployment.\u003c/p\u003e\u003cp\u003eFor the pressure monitoring group: The decision to perform coil packing was determined by intra-aneurysmal pressure changes after FD deployment. If the intrasaccular pressure decreased after FD placement, no coils were used; if the pressure increased, coils were packed until the pressure decreased or stabilized, after which packing was stopped.\u003c/p\u003e\u003cp\u003eFor the control group: Conventional FD therapy was administered for UIAs, and the decision to combine coil embolization (or not) was based on previous clinical experience.\u003c/p\u003e\u003cp\u003eAdditionally, to further investigate intrasaccular pressure changes after FD placement, patients in the pressure monitoring group were subdivided into a pressure increase subgroup and a pressure decrease subgroup, according to whether the intrasaccular pressure increased or decreased after FD deployment.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Pressure Monitoring Technique\u003c/h2\u003e\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\u003ch2\u003e2.3.1 Microcatheter verification\u003c/h2\u003e\u003cp\u003eThis study evaluated the accuracy of Echelon 10 microcatheter pressure measurements when using an in vitro silicone vascular model (Medtronic, Inc., USA) to simulate intracranial vascular anatomy (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The Echelon 10 microcatheter and a high-precision pressure guidewire (C12059, Abbott, USA) were placed in the same measurement position in the vascular model. Graded pressure signals were generated by precisely adjusting the saline infusion rate. Pearson's correlation coefficient analysis was used to assess the agreement between these two pressure measurements.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\u003ch2\u003e2.3.2 operation technique\u003c/h2\u003e\u003cp\u003eAll patients underwent general anesthesia, and bilateral femoral arteries were punctured using the Seldinger technique(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). An 8F arterial sheath was placed on one side, and a 5F arterial sheath on the other. After systemic heparinization, an 8F introducer catheter supported by a 5F intermediate catheter was advanced to the predetermined position via the 8F arterial sheath under the guidance of a loach guidewire. Subsequently, the 5F intermediate catheter was positioned in the internal carotid artery proximal to the intracranial aneurysm, with continuous and slow intravenous infusion of heparinized saline throughout the procedure. On the contralateral side, via the 5F arterial sheath and under the guidance of a loach guidewire, a 5F introducer catheter was placed in the internal carotid artery proximal to the intracranial aneurysm, on the same side as the 8F introducer catheter.\u003c/p\u003e\u003cp\u003eThree-dimensional reconstructed angiography was performed on the target-side internal carotid artery to measure the diameters of the parent artery at the distal and proximal ends of the aneurysm; an appropriately sized FD was selected based on these measurements. Meanwhile, the length of the aneurysm neck and the maximum diameter of the aneurysm dome were recorded. Systolic blood pressure was maintained at 110\u0026ndash;120 mmHg and stabilized, and arterial blood pressure was recorded once stabilized. Under the guidance of a microfilament, an Echelon 10 microcatheter (ev3 Neuro-vascular, Irvine, USA) was advanced through the 5F introducer catheter into the mid-region of the aneurysm sac. A disposable pressure transducer was connected to the distal end of the microcatheter to record the initial intrasaccular pressure (Figure S3), and the Echelon 10 microcatheter was kept in an appropriate position within the aneurysm sac. Under roadmap guidance, an FD stent microcatheter was introduced through the 5F intermediate catheter and positioned across the aneurysm. The FD was loaded into the microcatheter and gradually deployed starting from the distal end of the aneurysm, ensuring the aneurysm neck was within the effective working length of the FD. After complete deployment, stent massage was performed as needed to assist in stent expansion and optimal wall apposition. Three-dimensional high-precision reconstructed imaging of the stent was conducted to assess FD wall apposition. Following stent stabilization, the pressure data from the Echelon 10 microcatheter transducer and arterial blood pressure were recorded again to collect pressure parameters (Table S1). The need for coil embolization was evaluated based on intrasaccular pressure changes after FD deployment: if pressure decreased, no coils were used; if intrasaccular pressure increased, coils were deployed until the pressure decreased or stabilized. Subsequently, all catheters were withdrawn, and the femoral artery puncture sites were sealed using a vascular sealer. All procedures were performed by the same neurointerventionalist with more than 15 years of interventional experience.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e2.4 Data Analysis\u003c/h2\u003e\u003cp\u003eData normality was assessed using the Shapiro-Wilk test, and continuous variables that conformed to normal distribution were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation, and comparisons between groups were made using the independent samples t test; non-normally distributed data were expressed as median (interquartile spacing), and comparisons between groups were made using the Mann-Whitney U test. Categorical variables (e.g., gender, type of complication) were analyzed by chi-square test or Fisher's exact test. The correlation between pressure change indicators and the number of spring coils was analyzed by Pearson's correlation coefficient, and the subgroup analysis classified the patients in the manometry group into pressure rise subgroups and pressure fall subgroups according to the rise and fall of pressure after FD placement, and the differences in morphological parameters were compared using the \u003cem\u003et\u003c/em\u003e test for independent samples. A linear regression model was constructed to investigate the effect of body to neck ratio and other factors on ΔIAP/ΔMAP. The differences were analyzed using IBM SPSS Statistics 26.0, and \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered significant.\u003c/p\u003e\u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003e3.1. Patient and Aneurysm Characteristics\u003c/h2\u003e\u003cp\u003ePipeline Embolization Device (PED)\u0026mdash;a commonly used type of FD\u0026mdash;were successfully deployed in all 47 patients, achieving a 100% technical success rate, and there were no significant differences between the pressure monitoring group (n\u0026thinsp;=\u0026thinsp;23) and the control group (n\u0026thinsp;=\u0026thinsp;24) in terms of the following indicators (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) : demographic characteristics, ages of (59.8\u0026thinsp;\u0026plusmn;\u0026thinsp;9.0) and (55.8\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9) years (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.110), and the proportion of females was 82.6% and 79.2% (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.764), respectively.\u003c/p\u003e\u003cp\u003eIn terms of aneurysm morphology, the median aneurysm diameters were 7.16 mm and 5.28 mm (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.148), and the median DNR were 1.27 and 1.40 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.983), respectively (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The baseline confounders were comparable between the two groups, ensuring the validity of hemodynamic comparisons.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline Clinical Data: Pressure vs. Control Groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eClinical Characteristics\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePressure Monitoring Group(\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;23)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eControl Group(\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTest Statistic\u003c/p\u003e\u003cp\u003e(\u003cem\u003et\u003c/em\u003e/χ\u0026sup2;)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender (Male)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4(17.39%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5(20.83%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.090\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.764\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (Years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e59.78\u0026thinsp;\u0026plusmn;\u0026thinsp;9.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e55.75\u0026thinsp;\u0026plusmn;\u0026thinsp;7.90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.633\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.110\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e15(65.22%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e8(33.33%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e4.778\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.029\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDiabetes Mellitus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1(4.35%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2(8.33%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.312\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.576\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHyperlipidemia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1(4.35%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1(4.27%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.975\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmoking History\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0(0.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3(12.50%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e3.071\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.080\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAlcohol Consumption History\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0(0.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3(12.50%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e3.071\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.080\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003emRS Score\u0026thinsp;\u0026le;\u0026thinsp;1 on Admission\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e22(95.65%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e23(95.83%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.975\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e*Note: Data are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) for continuous variables and \u003cem\u003en\u003c/em\u003e (%) for categorical variables. Continuous variables were compared using independent-samples \u003cem\u003et\u003c/em\u003e-test, and categorical variables using chi-square (\u003cem\u003eχ\u003c/em\u003e\u0026sup2;) test. \u003csup\u003e*\u003c/sup\u003e\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 indicates statistical significance.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eIntergroup Differences in Aneurysm Characteristics: Pressure Monitoring Group vs. Control Group\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAneurysm Characteristics\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePressure Monitoring Group (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e\u003cp\u003e(Patients: \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;23)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eControl Group (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e\u003cp\u003e(Patients: \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTest Statistic (χ\u0026sup2;/\u003cem\u003eZ\u003c/em\u003e/\u003cem\u003et\u003c/em\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of Aneurysms (n)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAneurysm Location (n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; ICA, C4 Segment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1(4.34%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2(7.40%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; ICA, C5 Segment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4(17.39%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9(33.33%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; ICA, C6 Segment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13(56.52%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12(44.44%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; ICA, C7 Segment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5(21.74%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4(18.81%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRegular Aneurysm Morphology (n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23(1.00%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25(92.59%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.775\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.183\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAneurysm Size\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull;Maximum Dome Diameter (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7.16(4.50, 10.68)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.28(3.43, 10.09)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-1.447\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.148\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Neck Diameter (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.99\u0026thinsp;\u0026plusmn;\u0026thinsp;2.95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.62\u0026thinsp;\u0026plusmn;\u0026thinsp;1.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.921\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.061\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; DNR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.14(1.06, 1.36)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.40 (1.00, 1.86)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-1.501\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.133\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e*Note: 1. Data are presented as median (interquartile range, IQR) or mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) for continuous variables, and n (%) for categorical variables. 2. Chi-square test was not performed for aneurysm location due to small sample size in each anatomical segment. 3. Regular aneurysm morphology was analyzed using Fisher\u0026rsquo;s exact test; neck diameter was compared using independent-samples t-test; maximum dome diameter and DNR were analyzed using Mann-Whitney U test. 4. *\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 indicates statistical significance (no significant differences observed in this table).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.2. Validation of Microcatheter-Based Pressure Monitoring\u003c/h2\u003e\u003cp\u003eValidation of microcatheter-based pressure monitoring (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) showed that measurements obtained via the Echelon 10 microcatheter exhibited a strong positive correlation with pressure guidewire measurements, with a Pearson correlation coefficient of r\u0026thinsp;=\u0026thinsp;1.000 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001); the regression equation was determined as P\u003csub\u003e\u003cem\u003ewire\u003c/em\u003e\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.69\u0026thinsp;+\u0026thinsp;1.34\u0026times;P\u003csub\u003e\u003cem\u003emicrocatheter\u003c/em\u003e\u003c/sub\u003e (slope: 1.34; 95% confidence interval [CI] : 1.26\u0026ndash;1.42). The technical feasibility of real-time intrasaccular pressure monitoring during PED deployment was established by this.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e3.3. Pressure Changes After PED Deployment\u003c/h2\u003e\u003cp\u003eIn the pressure monitoring group (n\u0026thinsp;=\u0026thinsp;23), PED deployment significantly reduced the following hemodynamic parameters (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e):\u003c/p\u003e\u003cp\u003eIntrasaccular systolic pressure (ISP): Decreased by 11.8%, from 76.0 mmHg to 67.0 mmHg (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.041); Pressure ratios: ISP/systolic blood pressure (SBP) decreased by 6.25%, from 0.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14 to 0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.041); IAP/MAP decreased by 5.56%, from 0.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 to 0.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.019).\u003c/p\u003e\u003cp\u003eIn most cases, PED monotherapy achieved favorable hemodynamic changes, which confirms the core flow diversion mechanism that underpins PED-based treatment for UIAs.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePressure Changes: Pre- vs. Post-PED Deployment in the Pressure Monitoring Group\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePressure Indicator\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePre-PED Deployment\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePre-PED Deployment\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTest Statistic (\u003cem\u003et\u003c/em\u003e/\u003cem\u003eZ\u003c/em\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSBP (mmHg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e124.35\u0026thinsp;\u0026plusmn;\u0026thinsp;19.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e120.91\u0026thinsp;\u0026plusmn;\u0026thinsp;19.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.104\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.281\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDBP (mmHg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e67.65\u0026thinsp;\u0026plusmn;\u0026thinsp;10.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e67.35\u0026thinsp;\u0026plusmn;\u0026thinsp;10.95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.176\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.862\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMAP (mmHg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e82.43\u0026thinsp;\u0026plusmn;\u0026thinsp;10.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e81.13\u0026thinsp;\u0026plusmn;\u0026thinsp;11.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.661\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.516\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eISP (mmHg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e76.00 (65.00, 95.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e67.00 (56.00, 91.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-2.040\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.041*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIDP (mmHg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e69.43\u0026thinsp;\u0026plusmn;\u0026thinsp;13.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e65.22\u0026thinsp;\u0026plusmn;\u0026thinsp;15.91\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.614\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.121\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIAP (mmHg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e74.00\u0026thinsp;\u0026plusmn;\u0026thinsp;14.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e69.48\u0026thinsp;\u0026plusmn;\u0026thinsp;17.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.706\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.102\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eISP/SBP Ratio\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e2.171\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.041*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIDP/DBP Ratio\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.97 (0.87,1.12)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.91 (0.81,1.11)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-2.227\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.026*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIAP/MAP Ratio\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e2.541\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.019*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e*Note: 1. Data are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) for normally distributed variables and median (interquartile range, IQR) for non-normally distributed variables (sample size of the Pressure Monitoring Group: \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;23). 2. Paired t-test was used for normally distributed variables, including systemic arterial pressure parameters (SBP, DBP, MAP), intra-aneurysmal diastolic pressure (IDP), and intra-aneurysmal mean pressure (IAP). Wilcoxon signed-rank test (denoted by Z statistic) was used for non-normally distributed variables, including intra-aneurysmal systolic pressure (ISP), ISP/SBP ratio, IDP/DBP ratio, and IAP/MAP ratio. 3. \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 indicates statistical significance.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003e3.4. DNR\u0026thinsp;\u0026gt;\u0026thinsp;1.47 Predicts Post-PED Pressure Rise\u003c/h2\u003e\u003cp\u003eThe pressure-increase subgroup (n\u0026thinsp;=\u0026thinsp;8) within the pressure monitoring group had a significantly higher DNR than the pressure-decrease subgroup (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Linear regression analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e) confirmed that DNR could predict ΔIAP/ΔMAP, with the regression equation: ΔIAP/ΔMAP\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.25\u0026thinsp;+\u0026thinsp;0.17\u0026times;DNR (Pearson correlation coefficient \u003cem\u003er\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.69, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). This finding enables the identification of aneurysms requiring adjunctive coil embolization based on morphological features (i.e., DNR).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eInter-Subgroup Differences in DNR and Its Correlation with Hemodynamic Pressure Changes\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePressure Increase Subgroup (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePressure Decrease Subgroup (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;15)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eStatistical Test\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eCorrelation Analysis (\u003cem\u003er\u003c/em\u003e/\u003cem\u003eP\u003c/em\u003e)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDNR (Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003et\u003c/em\u003e\u0026thinsp;=\u0026thinsp;4.57, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLinear Regression: DNR vs. ΔIAP/ΔMAP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003er\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.69\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Slope\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.17\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Intercept\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026mdash;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-0.25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eNotes: 1. DNR is defined as the ratio of the aneurysm\u0026rsquo;s maximum dome diameter to its neck width. 2. Inter-subgroup comparison of DNR used the independent-samples t-test; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 indicates an extremely significant statistical difference. 3. Linear regression analysis demonstrated a significant positive correlation between DNR and ΔIAP/ΔMAP (change in intra-aneurysmal mean pressure relative to mean arterial pressure), whereΔIAP/ΔMAP is dimensionless.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003e3.5. Coiling Optimization Guided by Real-Time Pressure\u003c/h2\u003e\u003cp\u003eIn terms of coil utilization and packing density:\u003c/p\u003e\u003cp\u003eA reduction in the rate of FD combined with coil embolization was observed: the rate was 34.8% in the pressure monitoring group, whereas it reached 54.2% in the control group\u0026mdash;representing a 19.4% relative reduction compared with the control group (P\u0026thinsp;=\u0026thinsp;0.116) (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Coil packing density was significantly lower in the pressure monitoring group: the mean density was 7.23%\u0026plusmn;1.37%, as opposed to 17.89%\u0026plusmn;2.00% in the conventional control group. This translated to a statistically significant relative reduction of 10.66% in packing density between the two groups (P\u0026thinsp;=\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn summary, intraoperative real-time pressure monitoring not only enabled a reduction in coil usage but also ensured hemodynamic stability throughout the procedure\u0026mdash;validating the value of pressure guidance in optimizing coil-related treatment strategies.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eInter-Group Comparison of Coil Packing Density in Patients Undergoing FD Combined with Coil Embolization\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePressure Monitoring Group\u003c/p\u003e\u003cp\u003e(FD\u0026thinsp;+\u0026thinsp;Coils)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eControl Group\u003c/p\u003e\u003cp\u003e(FD\u0026thinsp;+\u0026thinsp;Coils)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTest Statistic (\u003cem\u003et\u003c/em\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSample Size (\u003cem\u003en\u003c/em\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8 (34.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e13 (54.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e2.467\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.116\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCoil Packing Density\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e7.23%\u0026plusmn;1.37%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.89%\u0026plusmn;2.00%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-4.070\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.001\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eNotes: 1. The percentages in parentheses (34.8% for the Pressure Monitoring Group, 54.2% for the Control Group) represent the proportion of patients receiving FD combined with coil embolization within each group. 2. Data presentation: Sample size is expressed as \u003cem\u003en\u003c/em\u003e (%); coil packing density is expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD. 3. Inter-group comparisons were performed using the independent-samples \u003cem\u003et\u003c/em\u003e-test. 4. Statistical significance: \u003csup\u003e*\u003c/sup\u003e\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003csup\u003e**\u003c/sup\u003e\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01; consistent with the manuscript\u0026rsquo;s statistical criteria.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\u003ch2\u003e3.6. Safety and Short-Term Outcomes\u003c/h2\u003e\u003cp\u003eIntraoperative pressure monitoring did not elevate procedural risk or impair therapeutic efficacy. At a median follow-up duration of 4.5 months, no significant differences were observed between the two groups in terms of complication incidence or neurological prognosis (assessed by mRS score, with mRS\u0026thinsp;\u0026le;\u0026thinsp;1 as a favorable outcome). (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePerioperative and Postoperative Outcomes: Pressure Monitoring Group vs. Control Group\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOutcome Parameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePressure Monitoring Group (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;23)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eControl Group (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTest Statistic (\u003cem\u003et\u003c/em\u003e/\u003cem\u003eZ\u003c/em\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOperative Time (min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e126.96\u0026thinsp;\u0026plusmn;\u0026thinsp;39.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e137.92\u0026thinsp;\u0026plusmn;\u0026thinsp;52.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-0.808\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.423\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative Hospital Stay (Days)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.00(3.00,7.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.00(3.00,6.75)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-0.205\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.838\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eImmediate Postoperative Angiography\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Aneurysm Sac Opacification\u0026sup1;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e19 (82.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18 (75%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e0.406\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e0.524\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Aneurysm Neck Opacification\u0026sup2;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4 (17.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6 (25%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Complete Occlusion\u0026sup3;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eNotes: 1. Normally distributed continuous variables (operative time) are expressed as Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, compared using the independent-samples \u003cem\u003et\u003c/em\u003e-test; Non-normally distributed continuous variables (postoperative hospital stay) are expressed as median (interquartile range, IQR), compared using the Mann-Whitney U-test ( \u003cem\u003eZ\u003c/em\u003e-value denotes the test statistic); 2. Angiography opacification grades are defined by the O\u0026rsquo;Kelly-Marotta (OKM) scale: \u0026sup1;OKM Grade A/B (aneurysm sac opacification); \u0026sup2;OKM Grade C (aneurysm neck opacification); \u0026sup3;OKM Grade D (complete occlusion). 3. No statistically significant differences were observed between groups for all outcomes (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05)\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Discussion​​","content":"\u003cp\u003eFD, featuring a flexible mesh structure with high metal coverage, have thoroughly revolutionized the endovascular treatment concept for UIAs by remodeling the hemodynamics of the parent artery, inducing intra-aneurysmal thrombosis, and promoting aneurysm neck endothelialization. Particularly for complex aneurysms that are difficult to treat with traditional embolization, the mid-term complete occlusion rate can reach 75%\u0026ndash;93.4%(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Its original design intent was to reduce unnecessary intrasaccular manipulation and thereby lower the risk of rupture. However, in clinical practice, there are significant global discrepancies regarding \"whether to combine FD with coil embolization\": the proportion of combined therapy was merely 0.9% (1/109) in the U.S. PUFs study(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e), 17.3% (33/191) in the global multicenter ASPIRe study(\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e), and as high as 48.3% (637/1322) in the large-scale Chinese multicenter PLUs study(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). This discrepancy essentially arises from the lack of evidence-based basis for \"the necessity of coil packing\" and \"the optimization of packing density\"\u0026mdash;while both standalone FD therapy and combined therapy can achieve satisfactory occlusion rates(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e), over-embolization increases procedural risks, and insufficient embolization may raise the risk of delayed aneurysm rupture (DAR). This contradiction urgently needs to be resolved.\u003c/p\u003e\u003cp\u003eAs the most fatal complication after FD deplayment, DAR has an incidence of only 3%\u0026ndash;5%(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e) but a mortality rate as high as 70%\u0026ndash;80%(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Its core trigger is believed to be intrasaccular hemodynamic disturbances following FD deployment, particularly pressure elevation(\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). An analysis of 60 DAR cases by Hou et al. confirmed that patients with DAR exhibited a significant increase in intra-aneurysmal pressure after FD deplayment(\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e); further studies using computational fluid dynamics (CFD) by Cebral et al. revealed that sustained intra-aneurysmal pressure elevation was observed in all 3 cases of rupture after FD treatment, while no such phenomenon was noted in 4 successfully treated cases(\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). However, CFD technology has inherent limitations: its accuracy is highly dependent on the setting of boundary conditions, and it cannot capture transient intraoperative hemodynamic states(\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e). This also prompted the 2024 Chinese Clinical Management Guidelines for UIAs to explicitly state: \"Individualized hemodynamic analysis is still in the research phase, and it is not recommended for guiding clinical decisions at present\"(\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). Previous attempts at pressure monitoring (e.g., dual-sensor wires) are difficult to popularize due to the risk of inducing aneurysm rupture from their rigid tips(\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e)\u0026mdash;obtaining real-time, safe intra-aneurysmal pressure data has become the key to breaking the bottleneck in FD therapy.\u003c/p\u003e\u003cp\u003eThis study innovatively developed a dual-validation pressure monitoring system integrating the \"Echelon 10 microcatheter and pressure guidewire\". Validated using an in vitro silicone vascular model, the measurements from the Echelon 10 microcatheter exhibited an extremely strong positive correlation with those from a high-precision pressure guidewire (Model C12059, Abbott) (Pearson correlation coefficient r\u0026thinsp;=\u0026thinsp;0.98\u0026ndash;1.000, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). A regression equation was established as follows: P\u003csub\u003e\u003cem\u003ewire\u003c/em\u003e\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.69\u0026thinsp;+\u0026thinsp;1.34\u0026times;P\u003csub\u003e\u003cem\u003emicrocatheter\u003c/em\u003e\u003c/sub\u003e (95% confidence interval [CI] for the slope: 1.26\u0026ndash;1.42). This system fully addresses the limitations of traditional pressure monitoring techniques: on one hand, it avoids the rupture risk associated with rigid pressure guidewires; on the other hand, through standardized normalization of \"intra-aneurysmal mean pressure/systemic mean arterial pressure (IAP/MAP)\", it eliminates the interference of individual blood pressure fluctuations on pressure assessment, enabling real-time and accurate intra-aneurysmal pressure monitoring during FD deployment. More importantly, all cases uniformly used the Pipeline Embolization Device (PED, a commonly utilized FD), and the procedures were performed by the same neurointerventionalist with over 15 years of interventional experience\u0026mdash;this ensured the homogeneity and comparability of the study data.\u003c/p\u003e\u003cp\u003eBased on this pressure monitoring system, the present study identified key hemodynamic patterns and quantitative thresholds for FD-based UIA treatment, providing core evidence for individualized therapy. First, FD deployment significantly improves the hemodynamic status of low-risk aneurysms. In the pressure monitoring group (n\u0026thinsp;=\u0026thinsp;23), after FD deployment, intra-aneurysmal systolic pressure (ISP) decreased by 11.8% (from 76.0 mmHg to 67.0 mmHg, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.041), and the ratio of IAP/MAP decreased by 5.56% (from 0.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 to 0.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16, P\u0026thinsp;=\u0026thinsp;0.019). Notably, the study observed a transient pressure elevation at the initial stage of FD deployment: when the distal end of the FD first covered the aneurysm neck, some cases exhibited temporary pressure rise due to \"unobstructed inflow but obstructed outflow,\" which led to the formation of unstable small vortices inside the aneurysm sac. However, the pressure gradually declined after complete FD deployment. This finding suggests that clinicians should pay attention to dynamic pressure changes during FD deployment to avoid misjudging therapeutic efficacy based on transient fluctuations.\u003c/p\u003e\u003cp\u003eSecond, a DNR\u0026thinsp;\u0026gt;\u0026thinsp;1.47 is a key predictive indicator for intra-aneurysmal pressure elevation after FD deployment. Subgroup analysis of the pressure monitoring group showed that the mean DNR of the pressure-increase subgroup (n\u0026thinsp;=\u0026thinsp;8) was 1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51, which was significantly higher than that of the pressure-decrease subgroup (0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.32, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Additionally, DNR was significantly positively correlated with ΔIAP/ΔMAP (Pearson correlation coefficient r\u0026thinsp;=\u0026thinsp;0.69, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with the regression equation: ΔIAP/ΔMAP\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.25\u0026thinsp;+\u0026thinsp;0.17\u0026times;DNR. When DNR\u0026thinsp;\u0026gt;\u0026thinsp;1.47, the aneurysm exhibits a \"bottle-like\" configuration, making it difficult for the FD to fully cover the aneurysm neck or effectively remodel the blood flow path. This leads to continuous blood flow into the aneurysm sac and subsequent pressure elevation\u0026mdash;this provides a mechanistic explanation for the morphological predisposing factors of DAR and is also consistent with the CFD conclusion by Cebral et al. that \"aneurysms with high DNR have more complex hemodynamics\"(\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Based on this, the study proposes a critical threshold of DNR\u0026thinsp;=\u0026thinsp;1.47: for aneurysms with DNR\u0026thinsp;\u0026le;\u0026thinsp;1.47, FD monotherapy is sufficient to achieve pressure stability (pressure decreased in 65.2% of cases); for aneurysms with DNR\u0026thinsp;\u0026gt;\u0026thinsp;1.47, adjunctive coil embolization is required to mitigate the risk of pressure elevation.\u003c/p\u003e\u003cp\u003eThird, real-time pressure monitoring can significantly optimize coil utilization strategies, enabling \"precision embolization\". In the pressure monitoring group, the rate of FD combined with coil embolization was 34.8%, which was a 19.4% reduction compared with 54.2% in the control group. Additionally, the mean coil packing density in the pressure monitoring group was 7.23%\u0026plusmn;1.37%, representing a significant 10.66% decrease compared with 17.89%\u0026plusmn;2.00% in the control group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001). Further correlation analysis revealed a strong negative correlation between coil packing density and ΔIAP/ΔMAP (Pearson correlation coefficient \u003cem\u003er\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.900, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001). When the coil packing density reached 7.23%, ΔIAP/ΔMAP\u0026thinsp;\u0026le;\u0026thinsp;0.1, indicating that intra-aneurysmal pressure was stabilized.\u003c/p\u003e\u003cp\u003eThis finding challenges the traditional belief that \"a high packing density (\u0026gt;\u0026thinsp;20%) is an essential prerequisite for ensuring therapeutic efficacy\"\u0026mdash;the role of coils is not to \"fill the aneurysm sac\", but to stabilize intra-aneurysmal pressure by attenuating systolic pressure peaks and reducing turbulence through the dual mechanisms of \"mechanical occupation to increase blood flow resistance\" and \"promoting thrombosis to occlude the aneurysm sac\". Meanwhile, the reduction in packing density delivers significant clinical and economic value: it not only did not increase the risk of complications (perioperative complication rate: 8.70% in the pressure monitoring group versus 12.5% in the control group, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.672) but also showed no differences from the control group in terms of short-term occlusion rate (78.26% in the pressure monitoring group versus 75.00% in the control group, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.792) and neurological prognosis (proportion of patients with mRS score\u0026thinsp;\u0026le;\u0026thinsp;1: \u0026gt;91% in both groups). This offers a new approach for the precise and cost-effective treatment of UIAs.\u003c/p\u003e\u003cp\u003eThis study still has limitations that need to be addressed in future research: First, it adopts a single-center, small-sample design (47 patients in total, 23 in the pressure monitoring group). Additionally, only internal carotid artery aneurysms were included, without covering complex subtypes such as fusiform and blister-like aneurysms\u0026mdash;thus, caution is required when generalizing the conclusions to aneurysms in other locations or of other types. Second, intraoperative pressure monitoring focused solely on immediate changes after FD deployment, lacking long-term dynamic pressure data. This precludes the assessment of the association between pressure stability and long-term occlusion or recurrence rates. Third, from a technical perspective, the spatial resolution of the pressure sensor (\u0026plusmn;\u0026thinsp;2 mmHg) and microcatheter positioning errors may introduce measurement biases. Furthermore, the median follow-up time was only 4.5 months, which is insufficient to fully assess the long-term DAR risk beyond 30 days. Extended follow-up periods are needed to verify the long-term safety of the combined treatment strategy.\u003c/p\u003e\u003cp\u003eIn conclusion, through a dual-dimensional exploration of \"real-time pressure monitoring-morphological analysis\", this study established key quantitative criteria for FD-based treatment of UIAs: a DNR\u0026thinsp;\u0026gt;\u0026thinsp;1.47 indicates a risk of intra-aneurysmal pressure elevation, requiring adjunctive coil embolization to a coil packing density of 7.23% to achieve pressure stabilization; meanwhile, pressure guidance reduces the coil usage rate by 19.4% and the coil packing density by 10.66%, optimizing treatment costs while ensuring therapeutic efficacy and safety. In the future, large-scale multicenter studies are needed not only to verify the generalizability of the DNR threshold but also to explore optimization directions for FD porosity and radial support force\u0026mdash;with the ultimate goal of promoting intraoperative pressure-guided FD therapy to become a standard paradigm in the clinical management of UIAs\u003c/p\u003e"},{"header":"5. Conclusions","content":"\u003cp\u003eIntraoperative real-time pressure monitoring exhibits favorable safety and feasibility in the treatment of UIAs using FD, and can effectively guide adjunctive coil embolization procedures. DNR\u0026thinsp;\u0026gt;\u0026thinsp;1.47 indicates an increased risk of intra-aneurysmal pressure elevation after FD deployment; such patients require adjunctive coil embolization, and a coil packing density of approximately 7.23% is sufficient to achieve intra-aneurysmal pressure stabilization. This therapeutic strategy provides a quantitative reference basis for the individualized treatment of UIAs and holds significant clinical application value.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study involves human participants, and the study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Gannan Medical University (Approval No. LLSC2023-171). All patients or their legal/authorized representatives provided written informed consent to participate in this study. Additionally, written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article (e.g., intraoperative pressure monitoring images in Figure S3).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no competing interests to declare.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJianguo Zhong\u003csup\u003e#\u003c/sup\u003e: Conception and design of the study; acquisition, analysis, and interpretation of data; drafting the initial manuscript; and revising it for important intellectual content.Renhui Yi\u003csup\u003e#\u003c/sup\u003e: Conception and design of the study; statistical analysis of data; critical revision of the manuscript for intellectual content; and final approval of the submitted version. These two authors (Jianguo Zhong and Renhui Yi) contributed equally to this work and share co-first authorship.\u003c/p\u003e\n\u003cp\u003eYu Jiang: Acquisition of clinical data; assistance in data validation; and revision of the manuscript for clarity.Junrong Lian: Contribution to intraoperative data collection; technical support for experimental procedures; and review of the manuscript.\u003c/p\u003e\n\u003cp\u003eGengsheng Mao\u003csup\u003e*\u003c/sup\u003e: Supervision of the study design; provision of critical intellectual input; securing funding; and final approval of the manuscript.Shaochun Yang\u003csup\u003e*\u003c/sup\u003e: Overall supervision of the project; finalization of the study protocol; critical revision of the manuscript for scientific accuracy; and responsibility for the integrity of the work.\u003c/p\u003e\n\u003cp\u003eNote:\u003csup\u003e\u0026nbsp;#\u003c/sup\u003e indicates co-first authors;\u003csup\u003e\u0026nbsp;*\u0026nbsp;\u003c/sup\u003eindicates corresponding authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was supported by Key Research and Development Project of Ganzhou Science and Technology Department (No. 2023LNS37753); National Natural Science Foundation of China (82360599); Natural Science Foundation of Jiangxi Province (20232BAB206121).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe raw data supporting the conclusions of this article (including clinical baseline data, intraoperative pressure parameters, and follow-up records) will be made available by the corresponding authors (Gengsheng Mao and Shaochun Yang) upon reasonable request, without undue reservation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe extend our sincere gratitude to Professor Qiu Chuanzhen and Dr. Liu Ming from the Department of Neurosurgery at the First Affiliated Hospital of South Jiangxi Medical University for their invaluable support in this research.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eShen, D. et al. Sex disparities in the risk of intracranial aneurysm rupture: a case-control study. \u003cem\u003eFront. Neurol.\u003c/em\u003e \u003cb\u003e15\u003c/b\u003e, 1483679 (2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Hoe, W. et al. Screening for Intracranial Aneurysms in Individuals with a Positive First-Degree Family History: A Systematic Review. \u003cem\u003eWorld Neurosurg.\u003c/em\u003e ;\u003cb\u003e151\u003c/b\u003e: (2021). 235\u0026thinsp;\u0026ndash;\u0026thinsp;48.e5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGu, L. et al. Global, Regional, and National Burden of Subarachnoid Hemorrhage: Trends From 1990 to 2021 and 20-Year Forecasts. \u003cem\u003eStroke\u003c/em\u003e \u003cb\u003e56\u003c/b\u003e (4), 887\u0026ndash;897 (2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eThilak, S. et al. Diagnosis and management of subarachnoid haemorrhage. \u003cem\u003eNat. Commun.\u003c/em\u003e \u003cb\u003e15\u003c/b\u003e (1), 1850 (2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKang, H. et al. Pipeline Embolization Device for Intracranial Aneurysms in a Large Chinese Cohort: Complication Risk Factor Analysis. \u003cem\u003eNeurotherapeutics\u003c/em\u003e \u003cb\u003e18\u003c/b\u003e (2), 1198\u0026ndash;1206 (2021).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLuo, B. et al. Pipeline Embolization device for intracranial aneurysms in a large Chinese cohort: factors related to aneurysm occlusion. \u003cem\u003eTher. Adv. Neurol. Disord\u003c/em\u003e. \u003cb\u003e13\u003c/b\u003e, 1756286420967828 (2020).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBecske, T. et al. Long-Term Clinical and Angiographic Outcomes Following Pipeline Embolization Device Treatment of Complex Internal Carotid Artery Aneurysms: Five-Year Results of the Pipeline for Uncoilable or Failed Aneurysms Trial. \u003cem\u003eNeurosurgery\u003c/em\u003e \u003cb\u003e80\u003c/b\u003e (1), 40\u0026ndash;48 (2017).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003e[Chinese guideline for the. clinical management of patients with unruptured intracranial aneurysms (2024)]. \u003cem\u003eZhonghua Yi Xue Za Zhi\u003c/em\u003e. \u003cb\u003e104\u003c/b\u003e (21), 1918\u0026ndash;1939 (2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTsukagoshi, E., Sato, H. \u0026amp; Kohyama, S. Delayed aneurysm rupture in a patient treated with flow redirection endoluminal device: A case report and literature review. \u003cem\u003eSurg. Neurol. Int.\u003c/em\u003e \u003cb\u003e13\u003c/b\u003e, 506 (2022).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShobayashi, Y. et al. Intra-aneurysmal hemodynamic alterations by a self-expandable intracranial stent and flow diversion stent: high intra-aneurysmal pressure remains regardless of flow velocity reduction. \u003cem\u003eJ. Neurointerv Surg.\u003c/em\u003e \u003cb\u003e5\u003c/b\u003e (Suppl 3), iii38\u0026ndash;42 (2013).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRahma, A. G. \u0026amp; Abdelhamid, T. Hemodynamic and fluid flow analysis of a cerebral aneurysm: a CFD simulation. \u003cem\u003eSN Appl. Sci.\u003c/em\u003e \u003cb\u003e5\u003c/b\u003e (2), 62 (2023).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShimano, K. et al. Understanding of boundary conditions imposed at multiple outlets in computational haemodynamic analysis of cerebral aneurysm. \u003cem\u003eJ. Biorheol.\u003c/em\u003e \u003cb\u003e33\u003c/b\u003e (2), 32\u0026ndash;42 (2019).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBoniforti, M. A., Magini, R. \u0026amp; Orosco Salinas, T. Hemodynamic Investigation of the Flow Diverter Treatment of Intracranial Aneurysm. \u003cem\u003eFluids\u003c/em\u003e \u003cb\u003e8\u003c/b\u003e (7), 189 (2023).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eThormann, M. et al. Computational Flow Diverter Implantation\u0026mdash;A Comparative Study on Pre-Interventional Simulation and Post-Interventional Device Positioning for a Novel Blood Flow Modulator. \u003cem\u003eFluids\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e (3), 55 (2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKallmes, D. F. et al. Aneurysm Study of Pipeline in an Observational Registry (ASPIRe). \u003cem\u003eInterv Neurol.\u003c/em\u003e \u003cb\u003e5\u003c/b\u003e (1\u0026ndash;2), 89\u0026ndash;99 (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSeldinger, S. I. Catheter replacement of the needle in percutaneous arteriography. A new technique. \u003cem\u003eActa Radiol. Suppl. (Stockholm)\u003c/em\u003e. \u003cb\u003e434\u003c/b\u003e, 47\u0026ndash;52 (2008).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRouchaud, A. et al. Delayed hemorrhagic complications after flow diversion for intracranial aneurysms: a literature overview. \u003cem\u003eNeuroradiology\u003c/em\u003e \u003cb\u003e58\u003c/b\u003e (2), 171\u0026ndash;177 (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBrinjikji, W. et al. Risk Factors for Ischemic Complications following Pipeline Embolization Device Treatment of Intracranial Aneurysms: Results from the IntrePED Study. \u003cem\u003eAJNR Am. J. Neuroradiol.\u003c/em\u003e \u003cb\u003e37\u003c/b\u003e (9), 1673\u0026ndash;1678 (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eClaassen, J., Thijssen, D. H. J., Panerai, R. B. \u0026amp; Faraci, F. M. Regulation of cerebral blood flow in humans: physiology and clinical implications of autoregulation. \u003cem\u003ePhysiol. Rev.\u003c/em\u003e \u003cb\u003e101\u003c/b\u003e (4), 1487\u0026ndash;1559 (2021).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eColby, G. P. et al. Immediate procedural outcomes in 44 consecutive Pipeline Flex cases: the first North American single-center series. \u003cem\u003eJ. Neurointerv Surg.\u003c/em\u003e \u003cb\u003e8\u003c/b\u003e (7), 702\u0026ndash;709 (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHou, K. et al. Delayed rupture of intracranial aneurysms after placement of intra-luminal flow diverter. \u003cem\u003eNeuroradiol. J.\u003c/em\u003e \u003cb\u003e33\u003c/b\u003e (6), 451\u0026ndash;464 (2020).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCebral, J. R. et al. Aneurysm rupture following treatment with flow-diverting stents: computational hemodynamics analysis of treatment. \u003cem\u003eAJNR Am. J. Neuroradiol.\u003c/em\u003e \u003cb\u003e32\u003c/b\u003e (1), 27\u0026ndash;33 (2011).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHuang, Q. et al. Hemodynamic changes by flow diverters in rabbit aneurysm models: a computational fluid dynamic study based on micro-computed tomography reconstruction. \u003cem\u003eStroke\u003c/em\u003e \u003cb\u003e44\u003c/b\u003e (7), 1936\u0026ndash;1941 (2013).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDinger, T. F. et al. Patients' Characteristics Associated With Size of Ruptured and Unruptured Intracranial Aneurysms. \u003cem\u003eBrain Behav.\u003c/em\u003e \u003cb\u003e14\u003c/b\u003e (11), e70161 (2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchneiders, J. J., VanBavel, E., Majoie, C. B., Ferns, S. P. \u0026amp; van den Berg, R. A flow-diverting stent is not a pressure-diverting stent. \u003cem\u003eAJNR Am. J. Neuroradiol.\u003c/em\u003e \u003cb\u003e34\u003c/b\u003e (1), E1\u0026ndash;4 (2013).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Flow diversion, Unruptured intracranial aneurysm, Intraoperative pressure monitoring, dome-to-neck ratio, Coils embolization","lastPublishedDoi":"10.21203/rs.3.rs-7969411/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7969411/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e\u003cp\u003eThis study investigates the clinical value of using flow diverter (FD) to treat patients with unruptured intracranial aneurysms (UIAs), specifically examining changes in aneurysm sac pressure and hemodynamics before and after intraoperative FD deployment to guide the need for additional coil embolization. The aim is to explore whether FD deployment sufficiently reduces aneurysm pressure, thereby minimizing or eliminating the need for coils.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eA prospective cohort study enrolled 47 patients with UIAs undergoing FD treatment at the First Affiliated Hospital of Gannan Medical University from February 2023 to November 2024. Patients were divided into a pressure monitoring group (n\u0026thinsp;=\u0026thinsp;23) and a control group (n\u0026thinsp;=\u0026thinsp;24) based on whether real-time pressure monitoring was performed intraoperatively. The pressure monitoring group determined additional coil embolization based on changes in aneurysm sac pressure before and after FD deployment; the control group followed conventional experience-based procedures. Clinical characteristics, intraoperative parameters, coil packing density, and follow-up outcomes were compared between groups. The relationship between the dome-to-neck ratio ratio (DNR) and pressure changes was analyzed.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eFollowing FD deployment, the intra-aneurysmal systolic pressure (ISP) decreased by 11.8% (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.041) in the pressure monitoring group, and the Intra-Aneurysmal Pressure (IAP) / Mean Arterial Pressure (MAP) ratio decreased by 5.56% (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.019). DNR was significantly higher in the pressure-increase subgroup than in the decrease subgroup (1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51 vs. 0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.32, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and positively correlated with ΔIAP/ΔMAP (\u003cem\u003er\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.69, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), suggesting DNR\u0026thinsp;\u0026gt;\u0026thinsp;1.47 predicts increased intravascular pressure. The combination of pressure monitoring and coils reduced the rate of coiling by 19.4% compared to the control group, with significantly lower filling density (7.23% \u0026plusmn; 1.37% vs. 17.89% \u0026plusmn; 2.00%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001). Follow-up showed no statistically significant differences between groups in occlusion rates or outcomes (mRS\u0026thinsp;\u0026le;\u0026thinsp;1).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eIntraoperative real-time pressure monitoring safely and effectively guides coil embolization during FD deployment for UIA. A DNR\u0026thinsp;\u0026gt;\u0026thinsp;1.47 indicates increased risk of intraluminal pressure rise after FD deployment; such patients require supplemental coils embolization to achieve a filling density of approximately 7.23% for pressure stabilization. This strategy helps reduce coil consumption and optimize individualized treatment plans.\u003c/p\u003e","manuscriptTitle":"Intraoperative Real-Time Intrasaccular Pressure Monitoring: A Feasible Strategy to Optimize Coil Utilization and Individualize Flow Diverter Therapy for Unruptured Intracranial Aneurysms","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-04 10:26:04","doi":"10.21203/rs.3.rs-7969411/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-04T18:54:36+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-03T12:36:36+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-24T22:28:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"181708209759149252269778970815065741234","date":"2025-11-21T12:21:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"58053768038256138373192069946375502426","date":"2025-11-21T00:02:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"255444256853759369814871312754439933879","date":"2025-11-19T06:45:10+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-19T00:53:25+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-19T00:40:54+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-04T15:41:13+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-31T06:56:13+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-10-31T06:52:39+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"32dc1991-4133-4e9c-b864-4e4c9afdfd98","owner":[],"postedDate":"November 4th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":57264454,"name":"Health sciences/Diseases"},{"id":57264455,"name":"Health sciences/Medical research"},{"id":57264456,"name":"Health sciences/Neurology"}],"tags":[],"updatedAt":"2026-02-11T21:53:25+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-04 10:26:04","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7969411","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7969411","identity":"rs-7969411","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}