Resolving Distal Vessel Occlusions Caused by Migrated Emboli: Outcomes of Modified Stent Retrieval Technique

Resolving Distal Vessel Occlusions Caused by Migrated Emboli: Outcomes of Modified Stent Retrieval Technique | 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 Resolving Distal Vessel Occlusions Caused by Migrated Emboli: Outcomes of Modified Stent Retrieval Technique Hong Suk Ahn, Jung Hyun Park, Jun Hyong Ahn, Hong Jun Jeon, Byung Moon Cho This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4220078/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract This study aimed to retrospectively evaluate the safety and effectiveness of a modified stent retrieval technique that controls the unsheathing level of the microcatheter in resolving distal vessel occlusions caused by migrated emboli. From January 2016 to February 2022, the modified stent retrieval technique was applied to 24 of 445 patients with acute large vessel occlusion strokes in the anterior circulation, featuring secondary embolus migration into M2, M3, A2, or A3 branches. The procedure included radiopaque stent retrieval systems, including Trevo XP 4 x 20 mm and Solitaire Platinum 4 x 20 mm. Coverage range was adjusted through partial re-sheathing of the delivery microcatheter after full unsheathing. After recanalizing the primary large vessel occlusion, secondary distal vessel occlusion occurred in 12/6/4/2 patients in the M2/M3/A2/A3 branches, respectively (time from puncture to primary large vessel occlusion recanalization: 45.5 ± 17 min). The modified TICI score was 2a and 2b in 8 and 16 patients, respectively, for primary large vessel occlusion. The one-pass rate of secondary distal vessel occlusions was 70.8%, and 23 of 24 patients achieved a final recanalization rate of at least TICI 2c at the migrated distal vessel occlusion (mean duration: 23.2 ± 14 min) without significant complications. At 3 months, 16 patients achieved favorable functional outcome (mRS, 0–2). Thus, this modified technique was simple and effective, demonstrating both safety and efficacy in resolving distal vessel occlusion caused by migrated emboli. Health sciences/Neurology/Neurological disorders/Neurovascular disorders Health sciences/Neurology/Neurological disorders/Stroke Cerebral stroke Mechanical thrombolysis Stents Figures Figure 1 Figure 2 Figure 3 INTRODUCTION Mechanical thrombectomy is a well-established treatment protocol for acute large vessel occlusion (LVO) stroke, with favorable clinical outcomes reported.[ 1 – 3 ] Despite its effectiveness, secondary occlusion rates, such as thrombus fragmentation, tortuous vessel course, anterograde flow through a collateral channel, and failure to use a balloon guiding device during the procedure have been reported in 7–11% of cases.[ 4 , 5 ] Unfortunately, the emergence of new distal vessel occlusions (DVO) can significantly affect the final TICI score and functional disability. For example, a distal MCA-M3 occlusion causing aphasia or an anterior cerebral artery occlusion causing monoplegia can have a devastating impact on patients’ functional independence.[ 6 – 9 ] Neurointerventionalists find it challenging to access and achieve successful recanalization in DVO, given the small caliber, fragility, and tortuous anatomy of these vessels, all of which can pose safety risks.[ 5 , 10 ] The tortuous arterial anatomy and small vessel caliber can complicate the use of stent retrievers and medium to large bore aspiration catheters, as navigating these distal vessels can be problematic, raising concerns about arterial trauma. To overcome these obstacles, the use of second-generation devices with a smaller profile or technical adjusting of the primary stent to reduce contact area are warranted to minimize the risk and achieve successful recanalization.[ 11 – 16 ] This study aimed to evaluate the safety and effectiveness of a modified stent retrieval (STR) technique for the removal of migrated emboli in the M2, M3, A2, and A3 segments during mechanical thrombectomy for acute LVO. This article follows the STROBE reporting guidelines. METHODS Patients This retrospective study was approved by the local institutional review board (KANGDONG 2023-07-010), and all participants provided informed consent. All procedures in studies involving human participants were performed in accordance with the ethical standards of the institutional and/or national research committee and the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. From January 2016 to February 2023, we enrolled a total of 24 of 445 (5.4%) consecutive patients who experienced secondary embolic migration to the distal branch (M2, M3, or A2, A3) after the primary intervention for acute LVO stroke in the anterior circulation at our institution. Emboli to new territory (ENT) was defined according to the standard angiographic anatomy.[ 17 ] The eligibility criteria for the modified STR technique for DVOs were as follows: after achieving complete recanalization of the primary LVO with a modified TICI (mTICI) score of 2a or 2b, the neurointerventionalist evaluated whether ENT affected the main blood supply to an eloquent area. Additionally, they evaluated if the device was accessible without vascular tortuosity or tension, and if retrograde filling into the ENT would prevent further ischemic progression. The exclusion criteria were as follows: evidence of intracranial hemorrhage or low density on the initial CT scan in the secondary migrated territory. All patients presented with symptoms of acute stroke and underwent a non-enhance CT and multiphase CT after neurological evaluation. The following data were collected and reviewed for all patients: age, sex, risk factors, baseline mRS score, NIHSS score, ASPECTS, use of tPA, time from symptom onset to arrival at the hospital, time from symptom onset to femoral puncture, time from femoral puncture to successful recanalization, location of primary LVO, migrated DVO, total procedural time (divided into primary LVO and secondary DVO), primary thrombectomy devices, secondary stent retriever, modified stent retriever attempts, final mTICI score [ 18 ], and other relevant information. Modified STR technique All mechanical thrombectomies were performed through femoral puncture while the patients were under conscious sedation. For the anterior circulation, a balloon guiding catheter (8 or 9 Fr BGC Cello/Medtronic, Irvine, California, USA or 9 Fr Optimo/Medtronic, Irvine, California, USA) or a non-balloon guiding catheter (Neuromax 6F or Fubuki 7F) was placed as distally as possible in the cervical ICA of the occluded side, using a 5-F long angio-catheter for navigation. The primary LVO site was initially accessed using the Trevo XP Provue 4 x 20 mm (Stryker Neurovascular, Fremont, CA, USA), Solitaire Platinum 4 x 20 mm (Medtronic, Dublin, Ireland), or Penumbra Reperfusion Catheter 5Max Ace 068. A microcatheter (Prowler Select Plus [Cordis, Dublin, OH, USA] or Markman 27 or Phenom 21 [Medtronic]) was navigated to the point of occlusion, and the length of thrombus and distal vascular nature was examined using super-selective angiography. In the event of ENT occurring in the DVO after successful recanalization of the primary LVO, either the Trevo XP Provue 4 x 20 mm (Stryker) or Solitaire Platinum 4 x 20 mm (Medtronic) retriever stent was applied. The deployed range was easily identified by the radiopaque wire or marker, respectively. The modified STR technique was used for clot removal and included adjusting the covered range of the stent by partially re-sheathing the delivery catheter after fully unsheathing it. The microcatheter and microwire maneuvered over the embolic lesion (Fig. 1 a), and the radiopaque stent retriever was carefully deployed inside the thrombus by unsheathing the microcatheter (Fig. 1 b). At this point, the waisted portion of the stent can be indicated by compression of the clot. After allowing 2 min for the clot to engage with the stent, the microcatheter was gently pushed forward to partially re-sheath the stent, reducing the physical friction between the parent artery and the stent (Fig. 1 c). Resistance during the re-sheathing process indicated that the clot was in contact with the microcatheter. The partially re-sheathed stent was slowly retrieved into the guide catheter by pulling back, with careful monitoring of the motion of the parent artery under an inflated balloon guiding the catheter or proximal aspiration catheter (Fig. 1 d). Complications and outcomes Procedure-related complications were recorded during the intra-angiography and post-procedural CT examinations. Stenosis of the targeted vessel and a double contour layer after retrieval were defined as arterial vasospasm and dissection. Vessel perforation was determined if a contrast leak occurred if a contrast leak was noted due to incorrect navigation of the microcatheter and microwire. Post-procedural CT scans were used to identify SAH and intracerebral hemorrhage (ICH), which was classified as Hemorrhagic Infarction type 1, 2 (HI 1,2) and Parenchymal Hematoma type 1, 2 (PH 1,2) according to the European Co-operative Acute Stroke Study-II (ECASS II) classification system. [ 19 ] Symptomatic ICH was defined as worsening of ≥ 4 points on the NIHSS scale clinical examination, accompanied by hemorrhage on CT after treatment. The primary LVO and secondary DVO before and after treatment were defined according to the mTICI classification. Successful revascularization was defined as an mTICI score of 2c or 3 and was determined by two blinded physicians based on the procedural process. Patients were routinely scheduled for MRI within 24–48 hours after the procedure. Regional ischemic findings associated with the ENT were evaluated post-recanalization of the DVO and classified into the following three categories: complete, partial, and none. Clinical outcomes were obtained from medical records using the NIHSS and mRS at discharge and 90 days after treatment. A good functional outcome was defined as a mRS score of ≤ 2 at three months. RESULTS During the study period, 24 out of 445 patients (5.4%) with acute large intracranial artery occlusions in the anterior circulation, treated with mechanical thrombectomy, developed ENT. All cases of DVOs were managed using the modified STR technique. The demographics, devices profiles, and procedural outcomes of patients are summarized in Table 1 . The mean age of the patients was 68.3 ± 9.1 years, with 62.5% being women. The median baseline NIHSS score was 12.3 ± 4.4, and 10 patients (41.7%) had received IV tPA within a 4.5-hour time window. The initial median ASPECTS was 8.5 ± 1.0, and the collateral state on multiphase CTA showed good collateral flow in 8 patients, moderate in 9 patients, and poor in 7 patients. Primary LVO was observed in 9 patients at the ICA and in 15 patients at the M1 segment, whereas secondary DVO was noted in 12, 6, 4, and 2 patients at the M2, M3, A2, and A3 segments, respectively. Initially, Solitaire 4 x 20 mm was used for LVO treatment in 9 patients, whereas Trevo 4 x 20 mm was used in 15 patients, with these devices consistently applied for secondary lesions without changing the thrombectomy device. In four patients, the ACE 068 reperfusion catheter was used as the first-line device without balloon guiding, and the DVO was successfully recanalized using the Trevo 4 x 20 mm via the modified STR technique. Overall, the primary LVO was fully recanalized, with mTICI 2a achieved in 33.3% (8/24) of patients and mTICI 2b achieved in 66.7% (16/24) of patients, with the condition being influenced by the presence of DVO in all cases. The modified STR technique for secondary DVO showed favorable outcomes, with a low number of procedural runs (mean 1.4 ± 0.6 times; range, 1–3) and achieved successful recanalization with TICI ≥ 2c in 95.8% (23/24) of patients, with a first-pass recanalization rate of 70.8% (17/24). Table 1 Demographics, device profiles and outcomes of study participants Case No Gender /Age Baseline NIHSS Initial ASPECTS Collateral CTA Primary LVO Secondary DVO Initial Device Secondary STR Primary LVO/ Final VO (mTICI) Modified STR (times) Complications Local infarction mRS at 3months 1 F/68 14 9 Moderate ICA A2 Solitaire Solitaire 2b / 3 1 PH type1 None 2 2 F/74 16 8 Moderate M1 M2 Solitaire Solitaire 2b / 3 1 Spasm None 3 3 F/79 18 7 Poor ICA A3 ACE 68/ Trevo Trevo 2a / 3 2 ― Partial 4 4 F/74 8 9 Good M1 M3 Trevo Trevo 2b / 3 1 ― Partial 2 5 F/67 10 8 Moderate ICA M2 ACE 68 Trevo Trevo 2a / 2c 1 ― None 1 6 M/63 10 9 Moderate ICA M3 Solitaire Solitaire 2b / 3 1 ― Complete 2 7 F/71 15 7 Poor M1 A2 ACE 68/ Trevo Trevo 2b / 3 1 PH type1 Complete 4 8 M/84 17 8 Poor ICA M3 ACE 68/ Trevo Trevo 2b / 3 2 SAH Complete 4 9 F/55 7 10 Good M1 M2 Trevo Trevo 2a / 3 1 ― None 1 10 M/54 9 9 Moderate M1 M2 Trevo Trevo 2b / 3 2 ― None 2 11 M/63 10 9 Moderate ICA M3 Solitaire Solitaire 2b / 3 1 ― Complete 2 12 F/81 16 7 Poor M1 A2 Trevo Trevo 2a / 3 1 ― Complete 3 13 M/85 19 8 Poor ICA M2 ACE 68/ Trevo Trevo 2a / 2a 3 Dissection, SAH Complete 5 14 M/59 8 9 Good M1 A3 Solitaire Solitaire 2b / 3 1 Spasm None 2 15 F/65 6 10 Good M1 M2 Trevo Trevo 2b / 3 1 ― None 0 16 F/54 7 9 Moderate M1 M2 Trevo Trevo 2a / 3 1 ― None 2 17 F/68 14 9 Good M1 A2 Solitaire Solitaire 2b / 3 1 ― None 1 18 M/67 12 8 Moderate M1 M2 Solitaire Solitaire 2b / 2c 1 ― None 2 19 F/71 18 7 Poor ICA M3 ACE 68/ Solitaire Solitaire 2b / 3 2 Spasm, PH type1 Complete 4 20 F/64 6 10 Good M1 M2 Trevo Trevo 2a / 3 1 ― None 0 21 F/72 16 9 Moderate M1 M2 Trevo Trevo 2b / 3 2 ― Partial 2 22 M/56 14 9 Good M1 M2 Solitaire Solitaire 2b / 2c 1 ― None 1 23 F/77 18 7 Poor ICA M2 ACE 68/ Trevo Trevo 2a / 3 3 Spasm, PH type1 Complete 3 24 M/67 8 10 Good M1 M3 Trevo Trevo 2b / 3 1 ― None 0 NIHSS, National Institute of Health Stroke Scale; ASPECTS, alberta stroke program early CT score; CTA, computed tomography angiography; LVO, large vessel occlusion; DVO, distal vessel occlusion; VO, vessel occlusion; STR, stent retrieval; mTICI, modified Thrombolysis in Cerebral Infarction; IH, intracranial hemorrhage; mRS, modified Rankin Scale; ICA, internal carotid artery; M1/ M2/ M3, M1/M2/M3 trunk of middle cerebral artery; A2/ A3, A2/ A3 trunk of anterior cerebral artery; PH, parenchymal hemorrhage; SAH, subarachnoid hemorrhage In terms of overall time metrics, the average time from symptom onset to hospital admission was 70 ± 54 min. The time from symptom onset to femoral puncture for the procedure was on average 110 ± 82 minutes. The mean recanalization time was 63.6 ± 12 min, with 45.5 ± 17 min for primary LVO cases and 23.2 ± 14 min for secondary DVO cases (Table 2 ). During the removal of the secondary clot, four instances of vessel spasms and one case of dissection occurred, with no vascular perforation observed. The vessel spasms spontaneously resolved, but the dissection eventually led to occlusion after the procedure. Asymptomatic ICH was observed in six patients on post-procedural CT, consisting of minor parenchymal hematoma type 1 (PH1) in four patients and subarachnoid hemorrhage in two patients, with no neurological deterioration noted. A routine follow-up MRI within 24–48 hours was performed for all patients. The presence of local ischemic findings was correlated with the recanalization of DVO, resulting in complete infarction in eight cases, partial infarction in three cases, and no infarction in 13 cases. At the 3-month mark, 16 patients had mild neurological sequelae (mRS ≤ 2), while eight patients were disabled (mRS > 2). Table 2 Time metrics of endovascular thrombectomy Procedural time Mean ± SD (min) Time from symptom onset to door 70 ± 54 Time from symptom onset to femoral puncture 110 ± 82 Time from femoral puncture to final recanalization 63.6 ± 12 Primary LVO 45.5 ± 17 Secondary DVO 23.2 ± 14 LVO, large vessel occlusion; DVO, distal vessel occlusion Illustrative cases Case 1 (Patient 5, Fig. 2 ) A 67-year-old woman presented with sudden-onset left-sided weakness and facial palsy, with a NIHSS score of 10. Initial CT revealed an ASPECTS of 8, whereas multiphase CTA revealed complete occlusion of the right ICA trunk with moderate collateral grade. Intravenous (IV) tPA was administered but proved ineffective. After continuous IV sedation, a 9 Fr balloon guide catheter was immediately placed at the proximal ICA. Using the ACE68 aspiration catheter with Trevo XP Provue 4 x 20 mm stent, successful recanalization of the distal ICA occlusion was achieved. However, a migrated embolus occurred at the right superior trunk of the M2 segment. The Trevo XP Provue 4 x 20 mm was immediately navigated to the DVO, and the modified STR technique was successfully applied to the migrated embolus, with full restoration of the blood flow as mTICI 2c Subsequent MRI the next day showed a minor infarction on the internal capsule. At the 3-month follow-up, the patient had a mild left-side weakness and a mRS score of 1. Case 2 (Patient 14, Fig. 3 ) A 59-year-old man presented with sudden-onset left-sided weakness with an NIHSS of 8. Initial CT showed an ASPECTS of 9, whereas multiphase CTA revealed right M1 trunk occlusion with good collateral grade. Given that the symptom onset was greater than 4.5 hours, IV tPA was not administered. An 8 Fr balloon guide catheter was immediately placed at the right proximal ICA, and using Solitaire Platinum 4 x 20 mm stent, recanalization of the right M1 occlusion was successfully achieved. During a retrieval of the stent, new embolic migration had occurred in the right A3 trunk. Continuously, the modified STR technique was applied to the targeted vessel using the same Solitaire stent, and the DVO was successfully recanalized into TICI 3. Procedure-induced vasospasm spontaneously resolved without sequelae. On the MRI taken the following day, a small infarction was noted in the left basal ganglia, insular, and frontal lobe area. At the three-month mark, the patient had recovered, with an mRS score of 2, indicating minimal speech disturbance. DISCUSSION In this retrospective study, we examined the safety and effectiveness of a modified STR technique for removing migrated emboli in the M2, M3, A2, and A3 segments during mechanical thrombectomy for acute LVO. Although a prospective randomized study has not yet conclusively established the safety and effectiveness of mechanical thrombectomy beyond the proximal segment, the American Heart Association and American Stroke Association (AHA-ASA) currently recommend it as a viable treatment option for selected patients. This recommendation is based on evidence from subgroup analyses of five randomized trials and meta-analyses [ 8 , 20 , 21 ]. Some studies have also suggested that untreated distal occlusions could progress into significant ischemic areas [ 4 , 6 – 8 , 21 ]. Interestingly, recent reports have demonstrated favorable outcomes with a higher reperfusion rate in distal arterial occlusions, such as M2-3, A2-3, and P2-3, using smaller instruments and experienced techniques. These reports did not show statistical differences in procedure-related complications, such as symptomatic ICH, vascular dissection, or perforation, compared to the treatment of proximal occlusions. Furthermore, they indicated clinical improvement by achieving better TICI scores through effective treatment of DVO [ 11 – 13 , 15 , 20 ]. Refining the approach to secondary DVOs that manifest during a procedure is crucial, given their conceptual distinctions from primary DVOs. Despite these differences, secondary DVOs often manifest with severe clinical symptoms, aggravated neurological deficits, larger ischemic extents, and increased clot fragility.[ 10 ] In a pioneering meta-analysis of safety and efficacy outcomes related to mechanical thrombectomy involving STR and aspiration in secondary DVOs, Rodriguez-Calienes et al. examined data from 14 studies encompassing 291 patients. Their findings revealed favorable outcomes, with a successful reperfusion rate (mTICI, ≥ 2b) of 82% and a symptomatic ICH rate of 6% [ 22 ]. Liu and colleagues identified a distinctive interaction between thrombus and stent retriever in the context of utilizing primary stents for DVOs and observed that the connection is superficial rather than the thrombus merging into the stent retriever, particularly when the embolus partially extends into the stent through its mesh [ 6 ]. In such cases, the stent, with its smaller diameter and narrower mesh, grips the embolus during partial retrieval. In our modified STR approach for local DVOs, the primary objective is to reduce the frictional force between the stent and the parent artery, minimizing the risk of vascular injury during the procedure. From our perspective on the modified STR technique in the local DVO, the aim is to decrease the frictional force between the stent and the parent artery, thereby minimizing the potential for vascular injury during the procedure. To achieve this, we recommend using stents like Trevo ProVue 4 x 20 mm and Solitaire Platinum 4 x 20 mm for vessels with a diameter of 2 to 4 mm. However, when applied in vessels with a diameter of 2 mm or less, retrieving the entire stent with its original radial force can often induce traction or shearing stress on the targeted vessels. Considering that migrated clots in distal vessels are usually fragmented into smaller sizes than primary clots, the radiopaque property of these stents allows operators to control friction at the M2 to M3 and A2 to A3 segments by adjusting the covering length of the microcatheter. After fully deploying the stent at the DVO to enhance clot entrapment, the microcatheter can be re-sheathed while providing local compression on the stent, confirmed by jammed resistance in the retrieval system. The deployment of low-profile stents and aspiration catheters, such as Baby Trevo, Catch Mini, various intermediate catheters, and Penumbra 3 or 4 Max, has shown promising outcomes in terms of both successful recanalization rates and one-pass success rates in cases of DVO [ 11 – 13 , 20 , 23 ]. Consistent studies have reported a meaningful success rate in vascular recanalization (TICI ≥ 2b), approximately ranging from 76–85%. This underscores the efficacy of these low-profile devices in effectively reopening obstructed blood vessels. Furthermore, the one-pass success rate, indicating successful vascular recanalization in a single attempt using these devices, has been reported to be approximately 48–60%. In a comparative analysis of favorable outcomes associated with these innovative low-profile devices in DVO treatment, our research reveals highly comparable and, in some respects, more impressive results. Specifically, it demonstrated a significantly higher success rate of mTICI 2c-3 reperfusion, accomplishing this outcome in 23 of 24 patients (95.8%) at the final recanalization stage, coupled with a superior one-pass success rate of 70.8%. Based on the available data, the reported rates of complications associated with supplementary procedures for secondary DVO align with findings from previous thrombectomy investigations [ 22 , 24 – 26 ]. Specifically, procedure-related vascular injuries have been reported in approximately 1–2% of cases, while post-procedural hemorrhagic tendencies have been observed in 4% of instances. Notably, this study identified the incidence of vessel spasm and dissection to be less than 1%, with these complications effectively addressed without resulting in severe consequences. Moreover, severe hemorrhagic changes linked to the procedure were also found to be less than 1%, indicating a low risk of significant bleeding complications. The occurrence of asymptomatic ICH was relatively rare, and importantly, no instances of neurological deterioration were observed in the patients. These findings robustly support the contention that the modified STR procedure represents a generally safe option, characterized by low complications and a favorable risk profile. When restoring blood flow to salvage brain tissue within an appropriate timeframe, the overall vascular distribution plays a crucial role in determining the extent and progression of cerebral infarction [ 27 , 28 ]. Several studies have reported that the initial status of collateral circulation significantly influences the size and scope of cerebral infarction, as well as the ultimate clinical outcomes following mechanical thrombectomy [ 29 , 30 ]. In the 24-hour follow-up diffusion-weighted image results assessing the occurrence of cerebral infarction after modified STR, individuals with good collateral status (8 cases) experienced partial infarction in 1 case, those with moderate collateral status (9 cases) exhibited partial infarction in 1 case, complete infarction in 2 cases, and those with poor collateral status (7 cases) had partial infarction in 1 case and complete infarction in 6 cases. At the 3-month follow-up, neurologically favorable outcomes were observed in 12 out of 13 cases without local infarction, 2 out of 3 cases with partial cerebral infarction, and 2 out of 8 cases with complete cerebral infarction. This suggests that, under certain circumstances with favorable initial collateral circulation, additional intervention with modified STR for DVO may lead to improved clinical outcomes. Furthermore, it offers advantages in terms of efficient time management and cost-effectiveness. Reported average procedural times for small-profile stents ranged from approximately 70–80 min, while aspiration catheters with a small diameter demonstrated procedural times of approximately 42–67 min for primary DVO [ 11 – 13 , 31 ]. In this specific context, the average procedure time for the modified STR technique was 23.2 ± 14 min, indicating a notably shorter duration compared to previous results targeting DVOs. These variations naturally depend on the preparation of the guiding and additional devices. Essentially, the stent initially employed for LVO can be utilized for secondary DVO without the need for additional tools. This repetitive use not only provides financial benefits to specific patients but also offers a practical solution for DVO, particularly in countries with limited reimbursement policies for available devices. This study has some limitations that should be considered. First, the retrospective design and relatively small sample size limit the generalizability of our findings. However, it is important to note that all data related to angiographic or clinical outcomes were prospectively registered in a core lab, ensuring the validity of the collected information. Second, the decision to perform the modified STR technique at the new embolic territory was based on the discretion of each neurointerventionalist, which may introduce a selection bias. Nonetheless, it is worth mentioning that all physicians involved in the study had extensive experience in performing mechanical thrombectomy for over 10 years, and the technique was a consensus among them in similar situations. Although the modified STR technique demonstrated promising application and reliable results for secondary migrated emboli beyond the proximal segment, further investigation is warranted to assess its specific benefits. Prospective comparisons with small-profile devices in primary DVO cases would provide a more comprehensive understanding of its efficacy and safety. CONCLUSIONS The modified STR technique showed remarkable success in achieving mTICI 2c-3 reperfusion, with a high rate of 95.8% and minimal occurrence of severe complications. Additionally, we achieved a one-pass rate of 70.8%, surpassing the rates reported with other small devices. These results provide strong evidence for the safety and effectiveness of the modified STR technique in effectively resolving DVO caused by migrated emboli. Declarations Author Contributions Conceptualization: Lead (Hong Suk Ahn), Supporting (Hong Jun Jeon) Data curation: Lead (Hong Suk Ahn), Supporting (Hong Jun Jeon) Formal analysis: Lead (Hong Suk Ahn), Supporting (Jung Hyun Park, Jun Hyong Ahn) Funding acquisition: Lead (Hong Jun Jeon), Supporting (Byung Moon Cho) Investigation: Lead (Hong Suk Ahn), Supporting (Jung Hyun Park, Jun Hyong Ahn, Hong Jun Jeon) Methodology: Lead (Hong Suk Ahn), Supporting (Jung Hyun Park, Jun Hyong Ahn) Project administration: Lead (Hong Jun Jeon), Supporting (Hong Suk Ahn) Resources: Lead (Hong Jun Jeon), Supporting Byung Moon Cho) Software: Lead (Hong Suk Ahn), Supporting (Jung Hyun Park, Jun Hyong Ahn) Supervision: Lead (Hong Jun Jeon), Supporting (Byung Moon Cho) Validation: Lead (Jun Hyong Ahn), Supporting (Jung Hyun Park) Visualization: Lead (Hong Suk Ahn), Supporting (Jun Hyong Ahn) Writing – original draft: Lead (Hong Suk Ahn), Supporting (Hong Jun Jeon) Writing – Review & editing: Lead (Hong Suk Ahn), Supporting (Byung Moon Cho) Data Availability statement The authors confirm that the data supporting the findings of this study are available within the article. Raw data that support the findings of this study are available from the corresponding author upon reasonable request. Funding This study was supported by the Hallym University Research Fund (grant number H20191021). Presentation N/A Ethical approval All procedures in studies involving human participants were performed in accordance with the ethical standards of the institutional and/or national research committee and the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent Informed consent was obtained from all study participants. Conflicts of interest: The authors declare no conflicts of interest related to the content of this article. References Berkhemer, O.A., et al. A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med. 372,11–20 (2015). https://doi.org/10.1056/NEJMoa1411587 Saver, J.L.,, et al. Stent-Retriever Thrombectomy after intravenous t-PA vs. t-PA Alone in Stroke. 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Endovascular thrombectomy for distal occlusion using a semi-deployed stentriever: Report of 2 cases and technical note. NeuroIntervention. 14,137–141 (2019). https://doi.org/10.5469/neuroint.2019.00143 Osborn AG. Diagnostic cerebral angiography. AJNR Am J Neuroradiol 1999;20:1767–1769 Kaesmacher, J., Maegerlein, C., Zibold, F., Wunderlich, S., Zimmer, C., Friedrich, B. Improving mTICI2b reperfusion to mTICI2c/3 reperfusions: A retrospective observational study assessing technical feasibility, safety and clinical efficacy. Eur Radiol. 28,274–282 (2018). https://doi.org/10.1007/s00330-017-4928-3 Hacke, W., et al. Randomised double-blind placebo-controlled trial of thrombolytic therapy with intravenous alteplase in acute ischaemic stroke (ECASS II). Second European-Australasian Acute Stroke Study Investigators. Lancet. 352(9136):1245–1251 (1998). https://doi.org/10.1016/S0140-6736(98)08020-9 Chartrain, A.G., et al. Aspiration thrombectomy with off-label distal access catheters in the distal intracranial vasculature. J Clin Neurosci. 45,140–145 (2017). Coutinho, J.M., et al. Mechanical thrombectomy for isolated M2 occlusions: A post hoc analysis of the STAR, SWIFT, and SWIFT PRIME studies. AJNR Am J Neuroradiol. 37,667–672 (2016). https://doi.org/10.3174/ajnr.A4591 Rodriguez-Calienes, A., et al. Mechanical thrombectomy for the treatment of primary and secondary distal medium-vessel occlusion stroke: Systematic review and meta-analysis. J NeuroInterv Surg. 15,e460-467 (2023). https://doi.org/10.1136/jnis-2022-019975 Park, J.S., Kwak, H.S. Manual aspiration thrombectomy using penumbra catheter in patients with acute M2 occlusion: A single-center analysis. J Korean Neurosurg Soc. 59,352–356 (2016). https://doi.org/10.3340/jkns.2016.59.4.352 Saber, H., et al. Mechanical thrombectomy for acute ischemic stroke with occlusion of the M2 segment of the middle cerebral artery: A meta-analysis. J NeuroInterv Surg. 10,620–624. (2018) https://doi.org/10.1136/neurintsurg-2017-013515 Grossberg, J.A., et al. Beyond large vessel occlusion strokes: Distal occlusion thrombectomy. Stroke. 49:1662–1668 (2018). https://doi.org/10.1161/STROKEAHA.118.020567 Sarraj, A., et al. Endovascular therapy for acute ischemic stroke with occlusion of the middle cerebral artery M2 segment. JAMA Neurol. 73,1291–1296 (2016). https://doi.org/10.1001/jamaneurol.2016.2773 Man, S., et al. Predictors of infarct growth after endovascular therapy for acute ischemic stroke. J Stroke Cerebrovasc Dis. 24,401–407 (2015). https://doi.org/10.1016/j.jstrokecerebrovasdis.2014.09.004 Puhr-Westerheide, D., et al. Clinical and imaging parameters associated with hyperacute infarction growth in large vessel occlusion stroke. Stroke. 50,2799–2804 (2019). https://doi.org/10.1161/STROKEAHA.119.025809 Al-Dasuqi, K., Effects of collateral status on infarct distribution following endovascular therapy in large vessel occlusion stroke. Stroke. 51:e193-202 (2020). https://doi.org/10.1161/STROKEAHA.120.029892 Agarwal, S., et al. Collateral response modulates the time-penumbra relationship in proximal arterial occlusions. Neurology. 90,e316-322 (2018). https://doi.org/10.1212/WNL.0000000000004858 Altenbernd, J., et al. Frontline ADAPT therapy to treat patients with symptomatic M2 and M3 occlusions in acute ischemic stroke: Initial experience with the Penumbra ACE and 3MAX reperfusion system. J Neurointerv Surg. 10,434–439 (2018). https://doi.org/10.1136/neurintsurg-2017-013233 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4220078","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":291771997,"identity":"dfea4a77-2d2d-4ac6-8425-5ec9374c0377","order_by":0,"name":"Hong Suk Ahn","email":"","orcid":"","institution":"Kangdong Sacred Heart Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hong","middleName":"Suk","lastName":"Ahn","suffix":""},{"id":291771999,"identity":"31c96368-9e3d-43d6-bb74-0685ca3d7edb","order_by":1,"name":"Jung Hyun Park","email":"","orcid":"","institution":"Hallym University Dongtan Sacred Heart Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jung","middleName":"Hyun","lastName":"Park","suffix":""},{"id":291772000,"identity":"bfbbe5e9-1e6d-4d99-aaf4-5c277cf9905f","order_by":2,"name":"Jun Hyong Ahn","email":"","orcid":"","institution":"Kangwon National University","correspondingAuthor":false,"prefix":"","firstName":"Jun","middleName":"Hyong","lastName":"Ahn","suffix":""},{"id":291772002,"identity":"81ee9a6e-21e7-4e40-bfc8-eff00255e925","order_by":3,"name":"Hong Jun Jeon","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3ElEQVRIiWNgGAWjYBACAxiDXwJMScgQr0VyBkQLD5BgbCBKi8ENCE1Yizl7d+KDjzl2eca3m589ulFjwcMg3Xz8AT4tlj1nNxvO3JZcbHbnmLlxzjGgw2SOJeJ32I3cbdK825gTt91IMJPOYQNqkcgxJKRl+2/ebfWJm2ekf5PO+QfSkv+RoC3MvNsOJ26QyDGTzm0D20IgxM6c3Sw5c9vxxBk3csqkc/skeNgk0gxn4NVyvHfjh4/bqhP7Z6Rvk875VifHL5H84AM+LZiAjTTlo2AUjIJRMAqwAQA4OUmgNh1SdAAAAABJRU5ErkJggg==","orcid":"","institution":"Kangdong Sacred Heart Hospital","correspondingAuthor":true,"prefix":"","firstName":"Hong","middleName":"Jun","lastName":"Jeon","suffix":""},{"id":291772003,"identity":"85fafaa3-10cd-4cbc-ae6f-17a219ef26c0","order_by":4,"name":"Byung Moon Cho","email":"","orcid":"","institution":"Kangdong Sacred Heart Hospital","correspondingAuthor":false,"prefix":"","firstName":"Byung","middleName":"Moon","lastName":"Cho","suffix":""}],"badges":[],"createdAt":"2024-04-05 00:14:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4220078/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4220078/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":55003385,"identity":"921f17d2-9795-4d04-ab69-9bbb809eabe7","added_by":"auto","created_at":"2024-04-19 18:42:19","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":640931,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSchematic Diagram of Modified Stent Retrieval Technique\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(a)\u003c/strong\u003e Microcatheter and microwire are moved over the distal occlusion site. (\u003cstrong\u003eb)\u003c/strong\u003e The stent retriever is fully deployed to the occlusion site. (\u003cstrong\u003ec)\u003c/strong\u003eThe microcatheter is pushed forward to partially re-sheath the stent. (\u003cstrong\u003ed)\u003c/strong\u003e The stent retriever and microcatheter are removed into the guide catheter. A1, A1 segment of anterior cerebral artery; M1, M1 segment of middle cerebral artery; M2, M2 segment of middle cerebral artery; ICA, internal cerebral artery\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-4220078/v1/d9197c73894e5e204aec66a2.png"},{"id":55003383,"identity":"fec4fc0a-c316-44f3-9ec0-a79ecdf2ad0a","added_by":"auto","created_at":"2024-04-19 18:42:19","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":470282,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eIllustrative Cases - Case 1\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(\u003cstrong\u003ea) \u003c/strong\u003eDistal migration of embolus at right superior trunk of M2. (\u003cstrong\u003eb)\u003c/strong\u003e Fully deployed Trevo XP Provue 4 x 20 mm. (\u003cstrong\u003ec) \u003c/strong\u003ePartial re-sheathing before removing the stent. (\u003cstrong\u003ed) \u003c/strong\u003eRemoved clot.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-4220078/v1/3f0145cbf4c50b56c054ecc9.png"},{"id":55003384,"identity":"2a9033fa-6a0d-473c-b5e9-5011031f0f7d","added_by":"auto","created_at":"2024-04-19 18:42:19","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":417540,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eIllustrative Cases - Case 2\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(\u003cstrong\u003ea) \u003c/strong\u003eDistal migration of embolus at right A3. (\u003cstrong\u003eb)\u003c/strong\u003e Fully deployed Solitaire Platinum 4 x 20 mm. (\u003cstrong\u003ec) \u003c/strong\u003ePartial re-sheathing before removing the stent. (d\u003cstrong\u003e) \u003c/strong\u003eRemoved clot.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-4220078/v1/cd86b2ac76b2881143b3ca11.png"},{"id":75998234,"identity":"41813d4c-7305-40ab-84fb-e9eadb0bb751","added_by":"auto","created_at":"2025-02-11 10:08:43","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2348334,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4220078/v1/282f2e0c-599a-45d2-bf41-c7c03afcfea9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Resolving Distal Vessel Occlusions Caused by Migrated Emboli: Outcomes of Modified Stent Retrieval Technique","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eMechanical thrombectomy is a well-established treatment protocol for acute large vessel occlusion (LVO) stroke, with favorable clinical outcomes reported.[\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] Despite its effectiveness, secondary occlusion rates, such as thrombus fragmentation, tortuous vessel course, anterograde flow through a collateral channel, and failure to use a balloon guiding device during the procedure have been reported in 7\u0026ndash;11% of cases.[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] Unfortunately, the emergence of new distal vessel occlusions (DVO) can significantly affect the final TICI score and functional disability. For example, a distal MCA-M3 occlusion causing aphasia or an anterior cerebral artery occlusion causing monoplegia can have a devastating impact on patients\u0026rsquo; functional independence.[\u003cspan additionalcitationids=\"CR7 CR8\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eNeurointerventionalists find it challenging to access and achieve successful recanalization in DVO, given the small caliber, fragility, and tortuous anatomy of these vessels, all of which can pose safety risks.[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] The tortuous arterial anatomy and small vessel caliber can complicate the use of stent retrievers and medium to large bore aspiration catheters, as navigating these distal vessels can be problematic, raising concerns about arterial trauma. To overcome these obstacles, the use of second-generation devices with a smaller profile or technical adjusting of the primary stent to reduce contact area are warranted to minimize the risk and achieve successful recanalization.[\u003cspan additionalcitationids=\"CR12 CR13 CR14 CR15\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eThis study aimed to evaluate the safety and effectiveness of a modified stent retrieval (STR) technique for the removal of migrated emboli in the M2, M3, A2, and A3 segments during mechanical thrombectomy for acute LVO. This article follows the STROBE reporting guidelines.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients\u003c/h2\u003e \u003cp\u003e This retrospective study was approved by the local institutional review board (KANGDONG 2023-07-010), and all participants provided informed consent. All procedures in studies involving human participants were performed in accordance with the ethical standards of the institutional and/or national research committee and the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.\u003c/p\u003e \u003cp\u003eFrom January 2016 to February 2023, we enrolled a total of 24 of 445 (5.4%) consecutive patients who experienced secondary embolic migration to the distal branch (M2, M3, or A2, A3) after the primary intervention for acute LVO stroke in the anterior circulation at our institution. Emboli to new territory (ENT) was defined according to the standard angiographic anatomy.[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] The eligibility criteria for the modified STR technique for DVOs were as follows: after achieving complete recanalization of the primary LVO with a modified TICI (mTICI) score of 2a or 2b, the neurointerventionalist evaluated whether ENT affected the main blood supply to an eloquent area. Additionally, they evaluated if the device was accessible without vascular tortuosity or tension, and if retrograde filling into the ENT would prevent further ischemic progression. The exclusion criteria were as follows: evidence of intracranial hemorrhage or low density on the initial CT scan in the secondary migrated territory. All patients presented with symptoms of acute stroke and underwent a non-enhance CT and multiphase CT after neurological evaluation. The following data were collected and reviewed for all patients: age, sex, risk factors, baseline mRS score, NIHSS score, ASPECTS, use of tPA, time from symptom onset to arrival at the hospital, time from symptom onset to femoral puncture, time from femoral puncture to successful recanalization, location of primary LVO, migrated DVO, total procedural time (divided into primary LVO and secondary DVO), primary thrombectomy devices, secondary stent retriever, modified stent retriever attempts, final mTICI score [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], and other relevant information.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eModified STR technique\u003c/h2\u003e \u003cp\u003eAll mechanical thrombectomies were performed through femoral puncture while the patients were under conscious sedation. For the anterior circulation, a balloon guiding catheter (8 or 9 Fr BGC Cello/Medtronic, Irvine, California, USA or 9 Fr Optimo/Medtronic, Irvine, California, USA) or a non-balloon guiding catheter (Neuromax 6F or Fubuki 7F) was placed as distally as possible in the cervical ICA of the occluded side, using a 5-F long angio-catheter for navigation. The primary LVO site was initially accessed using the Trevo XP Provue 4 x 20 mm (Stryker Neurovascular, Fremont, CA, USA), Solitaire Platinum 4 x 20 mm (Medtronic, Dublin, Ireland), or Penumbra Reperfusion Catheter 5Max Ace 068. A microcatheter (Prowler Select Plus [Cordis, Dublin, OH, USA] or Markman 27 or Phenom 21 [Medtronic]) was navigated to the point of occlusion, and the length of thrombus and distal vascular nature was examined using super-selective angiography. In the event of ENT occurring in the DVO after successful recanalization of the primary LVO, either the Trevo XP Provue 4 x 20 mm (Stryker) or Solitaire Platinum 4 x 20 mm (Medtronic) retriever stent was applied. The deployed range was easily identified by the radiopaque wire or marker, respectively.\u003c/p\u003e \u003cp\u003eThe modified STR technique was used for clot removal and included adjusting the covered range of the stent by partially re-sheathing the delivery catheter after fully unsheathing it. The microcatheter and microwire maneuvered over the embolic lesion (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea), and the radiopaque stent retriever was carefully deployed inside the thrombus by unsheathing the microcatheter (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). At this point, the waisted portion of the stent can be indicated by compression of the clot. After allowing 2 min for the clot to engage with the stent, the microcatheter was gently pushed forward to partially re-sheath the stent, reducing the physical friction between the parent artery and the stent (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec). Resistance during the re-sheathing process indicated that the clot was in contact with the microcatheter. The partially re-sheathed stent was slowly retrieved into the guide catheter by pulling back, with careful monitoring of the motion of the parent artery under an inflated balloon guiding the catheter or proximal aspiration catheter (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eComplications and outcomes\u003c/h2\u003e \u003cp\u003eProcedure-related complications were recorded during the intra-angiography and post-procedural CT examinations. Stenosis of the targeted vessel and a double contour layer after retrieval were defined as arterial vasospasm and dissection. Vessel perforation was determined if a contrast leak occurred if a contrast leak was noted due to incorrect navigation of the microcatheter and microwire. Post-procedural CT scans were used to identify SAH and intracerebral hemorrhage (ICH), which was classified as Hemorrhagic Infarction type 1, 2 (HI 1,2) and Parenchymal Hematoma type 1, 2 (PH 1,2) according to the European Co-operative Acute Stroke Study-II (ECASS II) classification system. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] Symptomatic ICH was defined as worsening of \u0026ge;\u0026thinsp;4 points on the NIHSS scale clinical examination, accompanied by hemorrhage on CT after treatment.\u003c/p\u003e \u003cp\u003eThe primary LVO and secondary DVO before and after treatment were defined according to the mTICI classification. Successful revascularization was defined as an mTICI score of 2c or 3 and was determined by two blinded physicians based on the procedural process. Patients were routinely scheduled for MRI within 24\u0026ndash;48 hours after the procedure. Regional ischemic findings associated with the ENT were evaluated post-recanalization of the DVO and classified into the following three categories: complete, partial, and none. Clinical outcomes were obtained from medical records using the NIHSS and mRS at discharge and 90 days after treatment. A good functional outcome was defined as a mRS score of \u0026le;\u0026thinsp;2 at three months.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003eDuring the study period, 24 out of 445 patients (5.4%) with acute large intracranial artery occlusions in the anterior circulation, treated with mechanical thrombectomy, developed ENT. All cases of DVOs were managed using the modified STR technique. The demographics, devices profiles, and procedural outcomes of patients are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The mean age of the patients was 68.3\u0026thinsp;\u0026plusmn;\u0026thinsp;9.1 years, with 62.5% being women. The median baseline NIHSS score was 12.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4, and 10 patients (41.7%) had received IV tPA within a 4.5-hour time window. The initial median ASPECTS was 8.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0, and the collateral state on multiphase CTA showed good collateral flow in 8 patients, moderate in 9 patients, and poor in 7 patients. Primary LVO was observed in 9 patients at the ICA and in 15 patients at the M1 segment, whereas secondary DVO was noted in 12, 6, 4, and 2 patients at the M2, M3, A2, and A3 segments, respectively. Initially, Solitaire 4 x 20 mm was used for LVO treatment in 9 patients, whereas Trevo 4 x 20 mm was used in 15 patients, with these devices consistently applied for secondary lesions without changing the thrombectomy device. In four patients, the ACE 068 reperfusion catheter was used as the first-line device without balloon guiding, and the DVO was successfully recanalized using the Trevo 4 x 20 mm via the modified STR technique. Overall, the primary LVO was fully recanalized, with mTICI 2a achieved in 33.3% (8/24) of patients and mTICI 2b achieved in 66.7% (16/24) of patients, with the condition being influenced by the presence of DVO in all cases. The modified STR technique for secondary DVO showed favorable outcomes, with a low number of procedural runs (mean 1.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6 times; range, 1\u0026ndash;3) and achieved successful recanalization with TICI\u0026thinsp;\u0026ge;\u0026thinsp;2c in 95.8% (23/24) of patients, with a first-pass recanalization rate of 70.8% (17/24).\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\u003eDemographics, device profiles and outcomes of study participants\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"14\"\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=\"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=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCase No\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003cp\u003e/Age\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBaseline NIHSS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eInitial\u003c/p\u003e \u003cp\u003eASPECTS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCollateral CTA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePrimary LVO\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eSecondary DVO\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eInitial\u003c/p\u003e \u003cp\u003eDevice\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSecondary\u003c/p\u003e \u003cp\u003eSTR\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003ePrimary LVO/ Final VO\u003c/p\u003e \u003cp\u003e(mTICI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eModified STR (times)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003eComplications\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003eLocal infarction\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c14\"\u003e \u003cp\u003emRS at 3months\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003ePH type1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eSpasm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eA3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eACE 68/ Trevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2a / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ePartial\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ePartial\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eACE 68\u003c/p\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2a / 2c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eComplete\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eACE 68/ Trevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003ePH type1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eComplete\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eACE 68/ Trevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eSAH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eComplete\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2a / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eComplete\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2a / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eComplete\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eACE 68/ Trevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2a / 2a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eDissection, SAH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eComplete\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eA3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eSpasm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2a / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 2c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eACE 68/ Solitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eSpasm, PH type1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eComplete\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2a / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003ePartial\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSolitaire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 2c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eF/77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eICA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eACE 68/ Trevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2a / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eSpasm, PH type1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eComplete\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eM/67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eM1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eM3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTrevo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2b / 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"14\"\u003eNIHSS, National Institute of Health Stroke Scale; ASPECTS, alberta stroke program early CT score; CTA, computed tomography angiography; LVO, large vessel occlusion; DVO, distal vessel occlusion; VO, vessel occlusion; STR, stent retrieval; mTICI, modified Thrombolysis in Cerebral Infarction; IH, intracranial hemorrhage; mRS, modified Rankin Scale; ICA, internal carotid artery; M1/ M2/ M3, M1/M2/M3 trunk of middle cerebral artery; A2/ A3, A2/ A3 trunk of anterior cerebral artery; PH, parenchymal hemorrhage; SAH, subarachnoid hemorrhage\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn terms of overall time metrics, the average time from symptom onset to hospital admission was 70\u0026thinsp;\u0026plusmn;\u0026thinsp;54 min. The time from symptom onset to femoral puncture for the procedure was on average 110\u0026thinsp;\u0026plusmn;\u0026thinsp;82 minutes. The mean recanalization time was 63.6\u0026thinsp;\u0026plusmn;\u0026thinsp;12 min, with 45.5\u0026thinsp;\u0026plusmn;\u0026thinsp;17 min for primary LVO cases and 23.2\u0026thinsp;\u0026plusmn;\u0026thinsp;14 min for secondary DVO cases (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). During the removal of the secondary clot, four instances of vessel spasms and one case of dissection occurred, with no vascular perforation observed. The vessel spasms spontaneously resolved, but the dissection eventually led to occlusion after the procedure. Asymptomatic ICH was observed in six patients on post-procedural CT, consisting of minor parenchymal hematoma type 1 (PH1) in four patients and subarachnoid hemorrhage in two patients, with no neurological deterioration noted. A routine follow-up MRI within 24\u0026ndash;48 hours was performed for all patients. The presence of local ischemic findings was correlated with the recanalization of DVO, resulting in complete infarction in eight cases, partial infarction in three cases, and no infarction in 13 cases. At the 3-month mark, 16 patients had mild neurological sequelae (mRS\u0026thinsp;\u0026le;\u0026thinsp;2), while eight patients were disabled (mRS\u0026thinsp;\u0026gt;\u0026thinsp;2).\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\u003eTime metrics of endovascular thrombectomy\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedural time\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD (min)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime from symptom onset to door\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e70\u0026thinsp;\u0026plusmn;\u0026thinsp;54\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime from symptom onset to femoral puncture\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e110\u0026thinsp;\u0026plusmn;\u0026thinsp;82\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime from femoral puncture to final recanalization\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e63.6\u0026thinsp;\u0026plusmn;\u0026thinsp;12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrimary LVO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e45.5\u0026thinsp;\u0026plusmn;\u0026thinsp;17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSecondary DVO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e23.2\u0026thinsp;\u0026plusmn;\u0026thinsp;14\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eLVO, large vessel occlusion; DVO, distal vessel occlusion\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eIllustrative cases\u003c/h2\u003e \u003cp\u003e \u003cstrong\u003eCase 1\u003c/strong\u003e \u003cp\u003e(Patient 5, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/p\u003e \u003cp\u003eA 67-year-old woman presented with sudden-onset left-sided weakness and facial palsy, with a NIHSS score of 10. Initial CT revealed an ASPECTS of 8, whereas multiphase CTA revealed complete occlusion of the right ICA trunk with moderate collateral grade. Intravenous (IV) tPA was administered but proved ineffective. After continuous IV sedation, a 9 Fr balloon guide catheter was immediately placed at the proximal ICA. Using the ACE68 aspiration catheter with Trevo XP Provue 4 x 20 mm stent, successful recanalization of the distal ICA occlusion was achieved. However, a migrated embolus occurred at the right superior trunk of the M2 segment. The Trevo XP Provue 4 x 20 mm was immediately navigated to the DVO, and the modified STR technique was successfully applied to the migrated embolus, with full restoration of the blood flow as mTICI 2c Subsequent MRI the next day showed a minor infarction on the internal capsule. At the 3-month follow-up, the patient had a mild left-side weakness and a mRS score of 1.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eCase 2\u003c/strong\u003e \u003cp\u003e(Patient 14, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/p\u003e \u003cp\u003eA 59-year-old man presented with sudden-onset left-sided weakness with an NIHSS of 8. Initial CT showed an ASPECTS of 9, whereas multiphase CTA revealed right M1 trunk occlusion with good collateral grade. Given that the symptom onset was greater than 4.5 hours, IV tPA was not administered. An 8 Fr balloon guide catheter was immediately placed at the right proximal ICA, and using Solitaire Platinum 4 x 20 mm stent, recanalization of the right M1 occlusion was successfully achieved. During a retrieval of the stent, new embolic migration had occurred in the right A3 trunk. Continuously, the modified STR technique was applied to the targeted vessel using the same Solitaire stent, and the DVO was successfully recanalized into TICI 3. Procedure-induced vasospasm spontaneously resolved without sequelae. On the MRI taken the following day, a small infarction was noted in the left basal ganglia, insular, and frontal lobe area. At the three-month mark, the patient had recovered, with an mRS score of 2, indicating minimal speech disturbance.\u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eIn this retrospective study, we examined the safety and effectiveness of a modified STR technique for removing migrated emboli in the M2, M3, A2, and A3 segments during mechanical thrombectomy for acute LVO. Although a prospective randomized study has not yet conclusively established the safety and effectiveness of mechanical thrombectomy beyond the proximal segment, the American Heart Association and American Stroke Association (AHA-ASA) currently recommend it as a viable treatment option for selected patients. This recommendation is based on evidence from subgroup analyses of five randomized trials and meta-analyses [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Some studies have also suggested that untreated distal occlusions could progress into significant ischemic areas [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Interestingly, recent reports have demonstrated favorable outcomes with a higher reperfusion rate in distal arterial occlusions, such as M2-3, A2-3, and P2-3, using smaller instruments and experienced techniques. These reports did not show statistical differences in procedure-related complications, such as symptomatic ICH, vascular dissection, or perforation, compared to the treatment of proximal occlusions. Furthermore, they indicated clinical improvement by achieving better TICI scores through effective treatment of DVO [\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRefining the approach to secondary DVOs that manifest during a procedure is crucial, given their conceptual distinctions from primary DVOs. Despite these differences, secondary DVOs often manifest with severe clinical symptoms, aggravated neurological deficits, larger ischemic extents, and increased clot fragility.[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] In a pioneering meta-analysis of safety and efficacy outcomes related to mechanical thrombectomy involving STR and aspiration in secondary DVOs, Rodriguez-Calienes et al. examined data from 14 studies encompassing 291 patients. Their findings revealed favorable outcomes, with a successful reperfusion rate (mTICI, \u0026ge; 2b) of 82% and a symptomatic ICH rate of 6% [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eLiu and colleagues identified a distinctive interaction between thrombus and stent retriever in the context of utilizing primary stents for DVOs and observed that the connection is superficial rather than the thrombus merging into the stent retriever, particularly when the embolus partially extends into the stent through its mesh [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In such cases, the stent, with its smaller diameter and narrower mesh, grips the embolus during partial retrieval. In our modified STR approach for local DVOs, the primary objective is to reduce the frictional force between the stent and the parent artery, minimizing the risk of vascular injury during the procedure. From our perspective on the modified STR technique in the local DVO, the aim is to decrease the frictional force between the stent and the parent artery, thereby minimizing the potential for vascular injury during the procedure. To achieve this, we recommend using stents like Trevo ProVue 4 x 20 mm and Solitaire Platinum 4 x 20 mm for vessels with a diameter of 2 to 4 mm. However, when applied in vessels with a diameter of 2 mm or less, retrieving the entire stent with its original radial force can often induce traction or shearing stress on the targeted vessels. Considering that migrated clots in distal vessels are usually fragmented into smaller sizes than primary clots, the radiopaque property of these stents allows operators to control friction at the M2 to M3 and A2 to A3 segments by adjusting the covering length of the microcatheter. After fully deploying the stent at the DVO to enhance clot entrapment, the microcatheter can be re-sheathed while providing local compression on the stent, confirmed by jammed resistance in the retrieval system.\u003c/p\u003e \u003cp\u003eThe deployment of low-profile stents and aspiration catheters, such as Baby Trevo, Catch Mini, various intermediate catheters, and Penumbra 3 or 4 Max, has shown promising outcomes in terms of both successful recanalization rates and one-pass success rates in cases of DVO [\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Consistent studies have reported a meaningful success rate in vascular recanalization (TICI\u0026thinsp;\u0026ge;\u0026thinsp;2b), approximately ranging from 76\u0026ndash;85%. This underscores the efficacy of these low-profile devices in effectively reopening obstructed blood vessels. Furthermore, the one-pass success rate, indicating successful vascular recanalization in a single attempt using these devices, has been reported to be approximately 48\u0026ndash;60%. In a comparative analysis of favorable outcomes associated with these innovative low-profile devices in DVO treatment, our research reveals highly comparable and, in some respects, more impressive results. Specifically, it demonstrated a significantly higher success rate of mTICI 2c-3 reperfusion, accomplishing this outcome in 23 of 24 patients (95.8%) at the final recanalization stage, coupled with a superior one-pass success rate of 70.8%.\u003c/p\u003e \u003cp\u003eBased on the available data, the reported rates of complications associated with supplementary procedures for secondary DVO align with findings from previous thrombectomy investigations [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Specifically, procedure-related vascular injuries have been reported in approximately 1\u0026ndash;2% of cases, while post-procedural hemorrhagic tendencies have been observed in 4% of instances. Notably, this study identified the incidence of vessel spasm and dissection to be less than 1%, with these complications effectively addressed without resulting in severe consequences. Moreover, severe hemorrhagic changes linked to the procedure were also found to be less than 1%, indicating a low risk of significant bleeding complications. The occurrence of asymptomatic ICH was relatively rare, and importantly, no instances of neurological deterioration were observed in the patients. These findings robustly support the contention that the modified STR procedure represents a generally safe option, characterized by low complications and a favorable risk profile.\u003c/p\u003e \u003cp\u003eWhen restoring blood flow to salvage brain tissue within an appropriate timeframe, the overall vascular distribution plays a crucial role in determining the extent and progression of cerebral infarction [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Several studies have reported that the initial status of collateral circulation significantly influences the size and scope of cerebral infarction, as well as the ultimate clinical outcomes following mechanical thrombectomy [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. In the 24-hour follow-up diffusion-weighted image results assessing the occurrence of cerebral infarction after modified STR, individuals with good collateral status (8 cases) experienced partial infarction in 1 case, those with moderate collateral status (9 cases) exhibited partial infarction in 1 case, complete infarction in 2 cases, and those with poor collateral status (7 cases) had partial infarction in 1 case and complete infarction in 6 cases. At the 3-month follow-up, neurologically favorable outcomes were observed in 12 out of 13 cases without local infarction, 2 out of 3 cases with partial cerebral infarction, and 2 out of 8 cases with complete cerebral infarction. This suggests that, under certain circumstances with favorable initial collateral circulation, additional intervention with modified STR for DVO may lead to improved clinical outcomes.\u003c/p\u003e \u003cp\u003eFurthermore, it offers advantages in terms of efficient time management and cost-effectiveness. Reported average procedural times for small-profile stents ranged from approximately 70\u0026ndash;80 min, while aspiration catheters with a small diameter demonstrated procedural times of approximately 42\u0026ndash;67 min for primary DVO [\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. In this specific context, the average procedure time for the modified STR technique was 23.2\u0026thinsp;\u0026plusmn;\u0026thinsp;14 min, indicating a notably shorter duration compared to previous results targeting DVOs. These variations naturally depend on the preparation of the guiding and additional devices. Essentially, the stent initially employed for LVO can be utilized for secondary DVO without the need for additional tools. This repetitive use not only provides financial benefits to specific patients but also offers a practical solution for DVO, particularly in countries with limited reimbursement policies for available devices.\u003c/p\u003e \u003cp\u003eThis study has some limitations that should be considered. First, the retrospective design and relatively small sample size limit the generalizability of our findings. However, it is important to note that all data related to angiographic or clinical outcomes were prospectively registered in a core lab, ensuring the validity of the collected information. Second, the decision to perform the modified STR technique at the new embolic territory was based on the discretion of each neurointerventionalist, which may introduce a selection bias. Nonetheless, it is worth mentioning that all physicians involved in the study had extensive experience in performing mechanical thrombectomy for over 10 years, and the technique was a consensus among them in similar situations. Although the modified STR technique demonstrated promising application and reliable results for secondary migrated emboli beyond the proximal segment, further investigation is warranted to assess its specific benefits. Prospective comparisons with small-profile devices in primary DVO cases would provide a more comprehensive understanding of its efficacy and safety.\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eThe modified STR technique showed remarkable success in achieving mTICI 2c-3 reperfusion, with a high rate of 95.8% and minimal occurrence of severe complications. Additionally, we achieved a one-pass rate of 70.8%, surpassing the rates reported with other small devices. These results provide strong evidence for the safety and effectiveness of the modified STR technique in effectively resolving DVO caused by migrated emboli.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization: Lead (Hong Suk Ahn), Supporting (Hong Jun Jeon)\u003c/p\u003e\n\u003cp\u003eData curation: Lead (Hong Suk Ahn), Supporting (Hong Jun Jeon)\u003c/p\u003e\n\u003cp\u003eFormal analysis: Lead (Hong Suk Ahn), Supporting (Jung Hyun Park, Jun Hyong Ahn)\u003c/p\u003e\n\u003cp\u003eFunding acquisition: Lead (Hong Jun Jeon), Supporting (Byung Moon Cho)\u003c/p\u003e\n\u003cp\u003eInvestigation: Lead (Hong Suk Ahn), Supporting (Jung Hyun Park, Jun Hyong Ahn, Hong Jun Jeon)\u003c/p\u003e\n\u003cp\u003eMethodology: Lead (Hong Suk Ahn), Supporting (Jung Hyun Park, Jun Hyong Ahn)\u003c/p\u003e\n\u003cp\u003eProject administration: Lead (Hong Jun Jeon), Supporting (Hong Suk Ahn)\u003c/p\u003e\n\u003cp\u003eResources: Lead (Hong Jun Jeon), Supporting Byung Moon Cho)\u003c/p\u003e\n\u003cp\u003eSoftware: Lead (Hong Suk Ahn), Supporting (Jung Hyun Park, Jun Hyong Ahn)\u003c/p\u003e\n\u003cp\u003eSupervision: Lead (Hong Jun Jeon), Supporting (Byung Moon Cho)\u003c/p\u003e\n\u003cp\u003eValidation: Lead (Jun Hyong Ahn), Supporting (Jung Hyun Park)\u003c/p\u003e\n\u003cp\u003eVisualization: Lead (Hong Suk Ahn), Supporting (Jun Hyong Ahn)\u003c/p\u003e\n\u003cp\u003eWriting \u0026ndash; original draft: Lead (Hong Suk Ahn), Supporting (Hong Jun Jeon)\u003c/p\u003e\n\u003cp\u003eWriting \u0026ndash; Review \u0026amp; editing: Lead (Hong Suk Ahn), Supporting (Byung Moon Cho)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirm that the data supporting the findings of this study are available within the article. Raw data that support the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by the Hallym University Research Fund (grant number H20191021).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePresentation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eN/A\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll procedures in studies involving human participants were performed in accordance with the ethical standards of the institutional and/or national research committee and the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed consent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from all study participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflicts of interest related to the content of this article.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBerkhemer, O.A., et al. 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J Neurointerv Surg. 10,434\u0026ndash;439 (2018). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1136/neurintsurg-2017-013233\u003c/span\u003e\u003cspan address=\"10.1136/neurintsurg-2017-013233\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Cerebral stroke, Mechanical thrombolysis, Stents","lastPublishedDoi":"10.21203/rs.3.rs-4220078/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4220078/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study aimed to retrospectively evaluate the safety and effectiveness of a modified stent retrieval technique that controls the unsheathing level of the microcatheter in resolving distal vessel occlusions caused by migrated emboli. From January 2016 to February 2022, the modified stent retrieval technique was applied to 24 of 445 patients with acute large vessel occlusion strokes in the anterior circulation, featuring secondary embolus migration into M2, M3, A2, or A3 branches. The procedure included radiopaque stent retrieval systems, including Trevo XP 4 x 20 mm and Solitaire Platinum 4 x 20 mm. Coverage range was adjusted through partial re-sheathing of the delivery microcatheter after full unsheathing. After recanalizing the primary large vessel occlusion, secondary distal vessel occlusion occurred in 12/6/4/2 patients in the M2/M3/A2/A3 branches, respectively (time from puncture to primary large vessel occlusion recanalization: 45.5\u0026thinsp;\u0026plusmn;\u0026thinsp;17 min). The modified TICI score was 2a and 2b in 8 and 16 patients, respectively, for primary large vessel occlusion. The one-pass rate of secondary distal vessel occlusions was 70.8%, and 23 of 24 patients achieved a final recanalization rate of at least TICI 2c at the migrated distal vessel occlusion (mean duration: 23.2\u0026thinsp;\u0026plusmn;\u0026thinsp;14 min) without significant complications. At 3 months, 16 patients achieved favorable functional outcome (mRS, 0\u0026ndash;2). Thus, this modified technique was simple and effective, demonstrating both safety and efficacy in resolving distal vessel occlusion caused by migrated emboli.\u003c/p\u003e","manuscriptTitle":"Resolving Distal Vessel Occlusions Caused by Migrated Emboli: Outcomes of Modified Stent Retrieval Technique","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-19 18:42:15","doi":"10.21203/rs.3.rs-4220078/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"073f66ab-ebbc-40ca-a90e-32d4cc80b235","owner":[],"postedDate":"April 19th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":30736272,"name":"Health sciences/Neurology/Neurological disorders/Neurovascular disorders"},{"id":30736273,"name":"Health sciences/Neurology/Neurological disorders/Stroke"}],"tags":[],"updatedAt":"2025-02-11T10:08:18+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-19 18:42:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4220078","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4220078","identity":"rs-4220078","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}