Transarterial Embolization of Type 2 Endoleak Using Coils and N-Butyl Cyanoacrylate: The Importance of Treating the Nidus and Sac Branches

Transarterial Embolization of Type 2 Endoleak Using Coils and N-Butyl Cyanoacrylate: The Importance of Treating the Nidus and Sac Branches | 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 Research Article Transarterial Embolization of Type 2 Endoleak Using Coils and N-Butyl Cyanoacrylate: The Importance of Treating the Nidus and Sac Branches Kenichiro Okumura, Takahiro Ogi, Junichi Matsumoto, Nobuyuki Asato, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4159651/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 Background Transarterial embolization (TAE) of the nidus and branches prevents aneurysm sac growth due to Type 2 endoleaks (T2EL). Embolization materials include coils and liquid embolic substances such as N-butyl-2-cyanoacrylate (NBCA) glue, a type of liquid embolic glue. However, when the nidus is characterized by heterogeneous perigraft opacity on CT imaging with an ill-defined boundary within the sac, it becomes challenging to embolize the nidus directly, often resulting in the embolization of only the branches connected to it. Therefore, we aim to evaluate the efficacy of TAE for the endoleak nidus and side branches versus embolizing the side branches alone in preventing aneurysm sac enlargement after T2EL, comparing mid-term follow-up results. Materials and Methods In a single-center retrospective cohort study, we reviewed consecutive 59 patients who underwent TAE for T2EL from September 2017 to August 2022. After excluding cases with less than 6 months follow-up or without abdominal aortic aneurysm, 40 patients were included in the analysis. Initial treatment for all patients included attempts at direct embolization of the endoleak nidus and side branches using coils and NBCA glue. Even if the nidus was reached, if embolization of the nidus proved difficult, the directly connected branches were embolized instead. Data were analyzed using the Kaplan–Meier curve for estimating sac enlargement freedom, with the primary outcome being aneurysm sac diameter change post-T2EL embolization. Results No visible endoleak nidus was detected in any patient after TAE. Of all patients (n = 40), 60% (n = 24) underwent embolization via direct cannulation to the nidus. Direct TAE involving the nidus and main branches with coils, supplemented with NBCA glue, considerably hindered sac enlargement (p < 0.0001). Of 14 patients with sac enlargement, 72% (10 patients) had unsuccessful direct TAE, resulting in a significant association (p = 0.006). On the other hand, 77% (20 of 26 patients) without sac enlargement experienced successful direct TAE. Three patients displayed sac enlargement even after successful direct TAE using only NBCA glue (p = 0.04). Conclusions Direct TAE of the endoleak nidus, using coils and supplemented with NBCA glue as necessary, is effective in preventing sac enlargement after T2EL embolization. Type 2 endoleak Embolization Coils N-butyl-2-cyanoacrylate glue Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 BACKGROUND Endovascular abdominal aortic aneurysm repair (EVAR) has gained global popularity as a preferred treatment option due to its lower perioperative mortality and complications than those of surgery (2005; Lederle et al. 2009; Prinssen et al. 2004). However, the most prevalent post-EVAR complication is known as type 2 endoleak (T2EL), occurring in 8–44% of patients following EVAR (Chaikof et al. 2018; Choke and Thompson 2004; D'Oria et al. 2020; Gelfand et al. 2006; Jones et al. 2007; Spanos et al. 2020). Although T2EL is generally considered a benign complication, it carries a potential risk of sac expansion and rupture (Deery et al. 2018; Jones et al. 2007; Seike et al. 2022). The natural history and treatment of T2EL remain subject to ongoing debate (Gonzalez-Urquijo et al. 2020). Typically, T2EL is typically managed conservatively, as many cases resolve spontaneously (Dijkstra et al. 2020; Jones et al. 2007; Walker et al. 2015). Various methods of embolizing T2EL have been documented (Chen and Stavropoulos 2020). While transarterial embolization (TAE) is a minimally invasive option, systematic reviews and meta-analyses indicate that its effectiveness is variable and not consistently superior to conservative treatments (Karthikesalingam et al. 2012; Sarac et al. 2012; Ultee et al. 2018). However, previous studies have yielded inconclusive regarding the relationship between the embolic material and the detailed levels of embolization. Moreover, existing evidence might underestimate the efficacy of additional treatment for persistent T2EL. In a recent multicenter study, moyamoya endoleak, a hard-to-embolize nidus, was identified as a predictor of reduced efficacy of TAE (Iwakoshi et al. 2023). Considering these perspectives, conducting comprehensive medium- to long-term evaluations and large-scale studies that address the procedural intricacies is crucial. Therefore, the purpose of this study is to compare the mid-term outcomes of embolizing both the endoleak nidus and branches versus the branches alone in preventing aneurysm sac enlargement following T2EL. Secondary to this, the study evaluates the impact of different embolic materials used in these procedures. MATERIALS AND METHODS Patients The institutional review board approved this retrospective cohort study, and the need for informed consent was waived. A review of the medical records and imaging studies was conducted for consecutive 59 patients who underwent TAE for type II endoleak between September 2017 and August 2022. Data from before the stent graft implantation was utilized as the medical record. One patient with Marfan syndrome and another with infection were excluded. Eleven patients with < 6 months of follow-up duration and six without abdominal aortic aneurysm (AAA) were excluded. Technical success was defined as the absence of detectable endoleaks during the completion angiogram at TAE (Details of technical success are available in the next section). No patient had concurrent endoleak types other than T2EL. Overall, 40 patients (31 men and 9 women, median age, 80 years [interquartile ranges (IQR) 75–85) years] who underwent TAE for T2EL following EVAR were enrolled. The decision to perform TAE for T2EL after EVAR was based on the presence of persistent T2EL with sac enlargement of > 5 mm in all cases. TAE Procedure The treatment strategy involves successful catheter advancement and embolization of the endoleak nidus and main feeding or drainage branches. In this study, the term "direct TAE" refers to the insertion of the catheter into the nidus via the arterial route followed by transarterial embolization. And, indirect TAE is defined as procedures that do not directly embolize the nidus. During angiography, when drainage branches from the endoleak nidus in the aneurysm were identified, these branches were selected and embolized with coils. Subsequently, embolization of the endoleak nidus and feeding branches was performed sequentially. The endoleak nidus and its associated branches were embolized using N-butyl-2-cyanoacrylate (NBCA) glue or coils. Indirect embolization refers to the practice of embolizing the main branches when it is not feasible to access the endoleak nidus or when the endoleak nidus is too small to accommodate the use of liquid embolization material without the risk of reflux. The patent aortic branches connecting to the endoleak nidus serving as feeding or drainage arteries for T2EL were identified through preprocedural contrast-enhanced computed tomography (CT) scans, with a slice thickness of 0.63-mm to 1.25-mm and angiograms conducted during the TAE procedure. The presence of coexisting endoleak types, other than T2EL, was checked utilizing the preprocedural contrast-enhanced CT scans and intraoperative angiograms. To address T2EL originating from the inferior mesenteric artery (IMA), accesse was gained to the middle colic artery through the superior mesenteric artery. The IMA was then cannulated via the arc of Riolan or the marginal artery. To address T2EL originating from the lumbar artery, the iliolumbar arteries were accessed via the internal iliac arteries, followed by retrograde cannulation of the lumbar artery. A 1.9-Fr non-tapered microcatheter (Carnelian MARVEL NT; Tokai Medical Product, Aichi, Japan) was advanced to the endoleak nidus through a 2.9-Fr microcatheter (Leonis Mova; SB Kawasumi, Kanagawa, Japan), coaxially introduced through a 4–5-Fr catheter. The embolization was performed using coils and NBCA glue. Specifically, coil embolization was performed using hydrogel-coated coils (Azur Soft 3D; Terumo, Tokyo, Japan) or detachable non-fibered coils (ED and i-ED COIL; Kaneka, Osaka, Japan). NBCA glue consists of a mixture of N-butyl-2-cyanoacrylate (Histoacryl; B.Braun, Melsungen, Germany) and iodized oil (Lipiodol; Guerbet, Aulnay-sous-Bois, France). The attending interventional radiologist determined the selection of embolization materials and the specified NBCA/Lipiodol ratio (16–50%) based on the target vessel anatomy. It was defined that successful embolization using coils and NBCA glue was achieved when the nidus was completely occluded by coils and NBCA glue, or if the nidus was embolized with NBCA glue, up to two associated branches could be successfully occluded using coils on the initial emobolization. If the embolization using coils and NBCA glue did not success, the procedure was classified as an embolization using only NBCA glue; this was observed in only three cases, where the concentration of NBCA glue used ranged from 16–25%. The procedural endpoint (technical success) was the absence of remarkably detectable endoleak nidus during the completion angiogram. No patients with substantial residual nidus during the completion angiogram were included in this study. The results and specific details of the TAE procedures were collected from the operative reports. Follow-up protocol Following the initial TAE, unenhanced CT scans were routinely performed at 1, 6, and 12 months, with subsequent annual scans if no sac enlargement was identified. Contrast-enhanced CT scans were conducted when sac enlargement, stent-graft migration, or sealing-zone shortening was identified. However, contrast media administration was avoided in patients with renal dysfunction or contrast medium intolerance. Imaging Outcomes Two radiologists with 10–20 years of experience conducted preprocedural and follow-up evaluations using CT scans and conventional angiograms, blind to the outcomes. Consensus was reached to resolve all discrepancies. The assessment included the measurement of the maximum aneurysmal sac diameter, moyamoya endoleak (Fig. 1 ), determination of endoleak presence and type. A Moyamoya endoleak was defined by its heterogeneous opacity with a faint and ill-defined edge. The final diagnosis was reached through a consensus. Maximum aneurysmal sac diameter was defined as the external diameter in the axial images. Aneurysmal sac enlargement was defined as a > 5mm increase in the maximum diameter compared to the sac diameter during the initial TAE. Predictors of Sac Enlargement After TAE for T2EL Patient characteristics and clinical factors were evaluated to investigate their potential association with sac enlargement following TAE. These included preprocedural demographics, clinical characteristics, smoking status, history of antiplatelet and anticoagulant use, and the type of EVAR device used. Others include aneurysmal sac diameter at the time of EVAR and initial TAE, the interval and sac growth between EVAR and initial TAE, follow-up duration following TAE, the number of patent aortic branches at the initial TAE, and the procedures of embolization. The embolization procedures were categorized into three groups as follows: direct TAE involving the nidus and its associated branches using coils incorporating NBCA glue as needed; direct TAE incorporating the nidus and its associated branches, utilizing only NBCA glue; and indirect TAE of associated branches, without nidus packing, using both coils incorporating NBCA glue as needed. There have been no cases where the nidus has been embolized with coils followed by embolization of the branches with NBCA glue. Statistical Analysis In cases of missing data or loss to follow-up, the last observation carried forward method was employed to impute missing values. Categorical variables were summarized using frequencies and percentages, while continuous variables were expressed using median and interquartile ranges. Fisher’s exact test was utilized to analyze clinical and TAE features (categorical variables). The Mann–Whitney test was used to analyze age, sac diameter, and the interval between EVAR and the first TAE. The Kaplan–Meier curve was utilized to estimate freedom from sac enlargement and reintervention rate, while the log-rank test was used for comparison. Statistical analyses were performed using GraphPad Software (Version 9.5.1 for Mac, San Diego, USA). A P value < 0.05 was considered statistically significant. RESULTS TAE Technique All patients exhibited attenuation of the nidus on the completion angiogram following TAE. Of these, 60% (n = 24) underwent embolization via direct cannulation to the nidus. In comparison, for the remaining 40% (n = 16), even if access to the nidus was achieved, embolization of the nidus itself was challenging, so embolization was performed on the branches directly connected to the nidus, targeting as many involved branches as possible. Among the patients who underwent nidus cannulation, 53% (n = 21) were embolized using a combination of coils and NBCA glue, while the remaining 7% (n = 3) were embolized solely with NBCA glue (Table 1 ). Table 1 Patient demographics, comorbidities and results of transarterial embolization procedure. Variables All, n = 40 Age 80 (76–85) Male sex 31 (78) Coronary artery disease 8 ( 20 ) Diabetes mellitus 5 ( 13 ) Chronic kidney disease 7 ( 18 ) Hypertension 37 (93) Dyslipidemia 29 (73) Peripheral artery disease 8 ( 20 ) Smoking - Current 3 ( 8 ) Former 23 (58) Never 14 (35) Anticoagulation 5 ( 13 ) Antiplatlet 24 60) Sac diameter at EVAR, mm 51 (45–56) Sac diameter at 1st TAE, mm 57 (51–62) EVAR device - Excluder 25 (63) Zenith 2 ( 5 ) Endurant 11 ( 28 ) AFX 2 ( 5 ) Sac enlargement 14 (35) Interval between EVAR and 1st TAE, m 41 (30–69) Follow up duration after 1st TAE, y 1.7 (0.9–2.8) Number of patent aortic branches at 1st TAE - 1 15 (38) 2 13 (32) 3 10 ( 25 ) 4 2 ( 5 ) Number of cases requiring 2 or more TAE 13 (33) Embolization location * (material) - Nidus and branches 24 (60) (Coil with/without NBCA glue) 21 (53) (Only NBCA glue) 3 ( 7 ) Branches without nidus (NBCA glue or Coil) 16 (40) Note.- Data are presented as counts (percentages) for the categorical variables or median (interquartile ranges) for the continuous variables. *Embolization procedures were classified based on whether the nidus was embolized and the type of embolic material used: either NBCA glue only or a combination of coils and NBCA glue as needed. There have been no cases where the nidus has been embolized with coils followed by embolization of the branches with NBCA glue. EVAR, endovascular abdominal aortic aneurysm repair; TAE, transarterial embolization; NBCA, N-butyl-2-cyanoacrylate. Imaging Outcomes The median sac diameter at the time of EVAR was 51 mm (IQR: 45–56), while the median sac diameter at the first TAE was 57 mm (IQR: 51–62). In 33% of patients (n = 13), two or more TAE procedures were required. Sac enlargement of > 5 mm following TAE was observed in 35% of patients (n = 14). The sac non-enlargement rates at 1, 3, and 5 years were 93%, 68%, and 65%, respectively (Fig. 2 ). Clinical Outcomes The median follow-up period was 1.7 years (IQR: 0.9–2.8 years) after the first TAE. Among the patients who underwent direct TAE for nidus and branches using a coil with or without NBCA glue (n = 24, 60%), the rates of sac non-expansion were 100%, 95%, and 95% at 1, 3, and 5 years, respectively (Figs. 3 and 4 ). In all patients (n = 3, 100%) in whom nidus with branches embolized exclusively using NBCA glue, sac enlargement was observed within 2 years, and the NBCA glue had disappeared in the images (Fig. 5 ). For patients who underwent embolization specifically for branches without direct TAE of the endoleak nidus (n = 16, 40%) (Supplemental Fig. 1), the rates of remaining free from sac enlargement were 81%, 44%, and 38% at 1, 3, and 5 years, respectively (Fig. 3 ). Factors Related to Moyamoya Endoleak In the group with moyamoya endoleak, a higher percentage of patients were administered antiplatelet medication than those without it (14 [82%] vs. 10 [43%], p = 0.02). The interval between EVAR and the first TAE was relatively longer in the group with moyamoya endoleak (52 days, IQR: 31–78) than in the group without it (37 days, IQR: 26–54). However, this difference was not statistically significant (p = 0.07). Moyamoya endoleak occurred significantly less frequently in the group that underwent direct TAE using coils, incorporating NBCA glue as needed (29%, n = 5), than in the opposite group (70%, n = 16, p = 0.02). Moyamoya endoleak was more prevalent in the group where direct TAE of the nibus could not be performed (59%, n = 10) than in the group without direct TAE (26%, n = 6). Nevertheless, the difference was insignificant (p = 0.053, Table 2 ). Table 2 Univariate comparison of factors associated with Moyamoya endoleak. Variables Moyamoya Endoleak P Yes n = 17 No n = 23 Age 84 (78–86) 79 (74–83) 0.04 Male sex 13 (76) 18 (78) > 0.99 Coronary artery disease 3 ( 18 ) 5 ( 22 ) > 0.99 Diabetes mellitus 3 ( 18 ) 2 ( 9 ) 0.63 Chronic kidney disease 4 ( 24 ) 3 ( 13 ) 0.43 Hypertension 17 (100) 20 (87) 0.25 Dyslipidemia 15 (88) 14 (61) 0.08 Peripheral artery disease 4 ( 24 ) 4 ( 17 ) 0.70 Smoking - - - Current 1 ( 6 ) 2 ( 9 ) > 0.99 Former 10 (59) 13 (57) > 0.99 Never 6 (35) 8 (35) > 0.99 Anticoagulation 1 ( 6 ) 4 ( 17 ) 0.37 Antiplatlet 14 (8 2 ) 10 (43) 0.02 Sac diameter at EVAR, mm 50 (45–55) 53 (43–58) 0.54 Sac diameter at 1st TAE, mm 56 (53–58) 58 (49–62) 0.72 EVAR device - - - Excluder 12 (71) 13 (57) 0.51 Zenith 1 ( 6 ) 1 ( 4 ) > 0.99 Endurant 3 ( 18 ) 8 (35) 0.30 AFX 1 ( 6 ) 1 ( 4 ) > 0.99 Sac enlargement 8 (47) 6 ( 26 ) 0.31 Interval between EVAR and 1st TAE, m 52 (31–78) 37 (26–54) 0.07 Number of patent aortic branches at 1st TAE - - - 1 6 (35) 10 (43) 0.75 2 7 (41) 5 ( 22 ) 0.30 3 4 ( 24 ) 6 ( 26 ) > 0.99 4 0 (0) 2 ( 9 ) > 0.99 Number of cases requiring 2 or more TAE 7 (41) 6 ( 26 ) 0.49 Embolization location* (material) - - - Nidus with branches - - - (Coil with/without NBCA glue) 5 (29) 16 (70) 0.02 (Only NBCA glue) 2 ( 12 ) 1 ( 4 ) 0.56 Branches without nidus (NBCA glue or Coil) 10 (59) 6 ( 26 ) 0.053 Note. - Data are presented as counts (percentages) for the categorical variables or median (interquartile ranges) for the continuous variables. *Embolization procedures were classified based on whether the nidus was embolized and the type of embolic material used: either NBCA glue only or a combination of coils and NBCA glue as needed. There have been no cases where the nidus has been embolized with coils followed by embolization of the branches with NBCA glue. EVAR, endovascular abdominal aortic aneurysm repair; TAE, transarterial embolization; NBCA, N-butyl-2-cyanoacrylate. Factors Contributing to Sac Enlargement after TAE for T2EL We analyzed 28 factors associated with sac enlargement of > 5 mm following TAE. Univariate analysis revealed that variables associated with sac enlargement (those with P values < 0.05) included the specific procedures (embolization with NBCA glue only and TAE for branches without nidus) and two or more TAE procedures (Table 3 ). Among the 14 patients who experienced sac enlargement, direct nidus TAE was unsuccessful in 10 (72%) (p = 0.006). Conversely, among the group of 26 patients who did not experience sac enlargement, 20 (77%) underwent successful embolization of the nidus and main branch using coils, incorporating NBCA glue as needed (p < 0.0001). Furthermore, sac enlargement was observed in three patients who, despite having undergone successful direct TAE of the nidus and branches, were exclusively embolized with NBCA glue (p = 0.04). Table 3 Univariate comparison of factors associated with sac enlargement. Variables Sac enlargement P Yes n = 14 No n = 26 Age 82 (76–84) 79 (74–83) > 0.99 Male sex 11 (79) 20 (77) 0.69 Coronary artery disease 2 ( 14 ) 6 ( 23 ) 0.64 Diabetes mellitus 1 ( 7 ) 6 ( 23 ) 0.41 Chronic kidney disease 3 ( 21 ) 4 ( 15 ) 0.28 Hypertension 12 (86) 25 (96) 0.47 Dyslipidemia 9 (64) 20 (77) 0.69 Peripheral artery disease 2 ( 14 ) 6 ( 23 ) Smoking - - > 0.99 Current 1 ( 7 ) 2 ( 8 ) 0.52 Former 7 (50) 16 (62) 0.50 Never 6 (43) 8 (31) 0.32 Anticoagulation 3 ( 21 ) 2 ( 8 ) 0.33 Antiplatlet 10 (71) 14 (54) > 0.99 Sac diameter at EVAR, mm 51 (48–56) 50 (44–57) 0.53 Sac diameter at 1st TAE, mm 57 (55–63) 57 (49–62) 0.46 EVAR device - - - Excluder 11 (79) 14 (54) 0.18 Zenith 1 ( 7 ) 1 ( 4 ) > 0.99 Endurant 2 ( 14 ) 9 (35) 0.27 AFX 0 (0) 2 ( 8 ) 0.53 Interval between EVAR and 1st TAE, m 42 (26–75) 40 (30–60) 0.81 Number of patent aortic branches at 1st TAE - - - 1 3 ( 21 ) 12 (46) 0.18 2 5 (36) 8 (31) > 0.99 3 6 (43) 4 ( 15 ) 0.12 4 0 (0) 2 ( 8 ) 0.53 Number of cases requiring 2 or more TAE 8 (57) 5 ( 19 ) 0.03 Embolization location * (material) - - - Nidus and branches - - - (Coil with/without NBCA glue) 1 ( 7 ) 20 (77) < 0.0001 (Only NBCA glue) 3 ( 21 ) 0 (0) 0.04 Branches without nidus (NBCA glue or Coil) 10 (72) 6 ( 23 ) 0.006 Data are presented as counts (percentages) for the categorical variables or median (interquartile ranges) for the continuous variables. * Embolization procedures were classified based on whether the nidus was embolized and the type of embolic material used: either NBCA glue only or a combination of coils and NBCA glue as needed. There have been no cases where the nidus has been embolized with coils followed by embolization of the branches with NBCA glue. EVAR endovascular abdominal aortic aneurysm repair; TAE, transarterial embolization; NBCA, N-butyl-2-cyanoacrylate. DISCUSSION This study investigated the results of embolization methods applied to T2EL after EVAR. The results highlighted the significant impact on sac diameter when successful direct TAE of both the nidus and its associated branches was achieved. Furthermore, apart from previously reported risk factors for sac enlargement, there was a notable correlation between direct embolization techniques, using coils and incorporating NBCA glue as needed, and sac enlargement. Among patients who underwent successful direct TAE, the rates of sac non-expansion were 100%, 95%, and 95% at 1, 3, and 5 years, respectively. Previous reports suggested that sac diameter before embolization influenced the embolic effect of TAE (Horinouchi et al. 2020). Contrary to the findings in those reports, this study revealed that successful direct TAE of the nidus and branches, with the adjunctive use of coils and as-needed NBCA glue, was the critical factor influencing sac diameter reduction. A history of dyslipidemia and the use of antiplatelet medications are associated with multiple embolization procedures, and smoking and the presence of a moyamoya nidus, characterized by unclear boundaries, were known factors that weaken the effect of TAE on the inhibition of sac diameter increase (Charitable et al. 2021; Iwakoshi et al. 2023; Sarac et al. 2012). The larger the thrombus volume in the sac, the more effectively it inhibited the increase in sac diameter (Fujii et al. 2020). The results of the current study suggest that moyamoya endoleak is associated with the use of antiplatelet agents, suggesting that inadequate thrombosis of the aneurysm may lead to moyamoya endoleak. Although achieving effective embolization in the presence of moyamoya endoleak is challenging (Iwakoshi et al. 2023), it is speculated that the antiplatelets effects, in addition to the small size of the nidus making it difficult to embolize, may contribute to the reduced efficacy of the embolization process. And then, based on the results of this study, two important technical factors in endoleak embolization were identified, the first being direct nidus embolization. This was consistent with many reports indicating the usefulness of embolization via direct puncture of the nidus (Guo et al. 2020; Mewissen et al. 2017; Nana et al. 2022). Furthermore, in some reports, embolization of the branch was not always necessary if the nidus was properly embolized (Yu et al. 2017). In a meta-analysis, it was observed that direct puncture embolization of the nidus achieved a higher clinical success rate than TAE. This difference in clinical success could be attributed to variations in the rate of embolization directly to the nidus (Guo et al. 2020). In contrast, embolization of the branch alone increased sac diameter even when the endoleak was properly embolized (Sarac et al. 2012). This finding was consistent with the conclusion that proper nidus embolization was necessary. The study also found that embolization of only the branches was less effective than direct TAE of the nidus and branches in preventing sac enlargement, even if the embolization was performed at a level directly connected to the nidus. These results supported that direct TAE of nidus and branches was an important technical component in endoleak embolization. Another important consideration was using coils for embolization to prevent loss of embolic material in the nidus. TAE with liquid embolic material was reported as a useful tool for the embolization of T2EL. However, it is essential to note that these reports had a limited follow-up period of only 2 years (Abularrage et al. 2012). Also, TAE involving the nidus and branches using coils has been documented as beneficial. However, the particular report had a relatively short follow-up period of approximately 1 year (Kasirajan et al. 2003). This study revealed that embolizing branches exclusively with NBCA glue resulted in a statistically significant increase in sac diameter while using coils in the embolization of the nidus and its associated branches might contribute to inhibiting an increase in sac diameter. Based on these findings, it can be concluded that using non-dissipating embolic materials for nidus embolization might be an effective strategy to prevent sac enlargement. This study had some limitations. First, owing to its retrospective and limited-scale design. The relatively small size of the patient subgroups poses a challenge for robust statistical interpretation. Second, accurately determining T2EL associated branches may be challenging because of the inability to perform contrast-enhanced CT scans in certain patient categories, including those with renal dysfunction, contrast medium intolerance, or absence of sac enlargement. And, angiographic visualization via a 1.9 Fr catheter typically fails to adequately opacify the nidus and the entirety of inflow/outflow branches, potentially obscuring the true anatomical and pathophysiological details of the endoleak. Should two or more branch vessels remain patent, the specific embolic agent used within the nidus and/or branch vessels may be inconsequential, as persistent flow can facilitate aneurysmal growth and allow the embolic material to displace from its initial placement. Therefore, this study does not assert the efficacy of using NBCA alone to embolize all potentially nidus-related inflow/outflow branches. Consequently, this study may underrepresent the occlusive efficacy of NBCA when used as the sole embolic agent.Third, it is important to note that this study followed the Japanese guidelines, focusing on EVAR treatment for smaller AAAs. This could potentially introduce a bias into this results, as the European Society for Vascular Surgery guidelines recommend considering larger AAA sizes. So, given that aneurysmal sac diameter is known to influence natural growth rates, this discrepancy could potentially affect T2EL efficacy outcomes in larger AAAs. Therefore, future studies focusing on larger AAA are required to verify these preliminary findings. CONCLUSIONS The results indicated that embolization of both the nidus and its associated branches using coils, incorporating NBCA glue as needed, was effective in preventing sac diameter increase in T2EL embolization. Embolization targeting the nidus with embolic agents that will not wash out may be an important therapeutic strategy for preventing aneurysmal expansion due to type 2 endoleak. Abbreviations TAE transarterial embolization T2EL type 2 endoleak NBCA N-butyl-2-cyanoacrylate EVAR Endovascular abdominal aortic aneurysm repair Declarations Ethics approval and consent to participate The Institutional Review Board approved this retrospective cohort study and waived the requirement for written informed consent. Consent for publication Not applicable Availability of data and material The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding Not applicable Author contributions KO , JM , TO: Visualization, Formal analysis, Writing – review & editing. NA, AY, TS, TO: Data curation. KK, SK: Writing – review & editing. KO, TO: Conceptualization, Methodology, Validation, Supervision, Writing – review & editing. Acknowledgements Not applicable References Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial. Lancet 365(9478):2187-2192. https://doi.org/10.1016/s0140-6736(05)66628-7. Abularrage CJ, Patel VI, Conrad MF, Schneider EB, Cambria RP, Kwolek CJ (2012) Improved results using Onyx glue for the treatment of persistent type 2 endoleak after endovascular aneurysm repair. J Vasc Surg 56(3):630-636. https://doi.org/10.1016/j.jvs.2012.02.038. Chaikof EL, Dalman RL, Eskandari MK, Jackson BM, Lee WA, Mansour MA, Mastracci TM, Mell M, Murad MH, Nguyen LL, Oderich GS, Patel MS, Schermerhorn ML, Starnes BW (2018) The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm. J Vasc Surg 67(1):2-77.e72. https://doi.org/10.1016/j.jvs.2017.10.044. 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Deery SE, Ergul EA, Schermerhorn ML, Siracuse JJ, Schanzer A, Goodney PP, Cambria RP, Patel VI (2018) Aneurysm sac expansion is independently associated with late mortality in patients treated with endovascular aneurysm repair. J Vasc Surg 67(1):157-164. https://doi.org/10.1016/j.jvs.2017.06.075. Dijkstra ML, Zeebregts CJ, Verhagen HJM, Teijink JAW, Power AH, Bockler D, Peeters P, Riambau V, Becquemin JP, Reijnen M (2020) Incidence, natural course, and outcome of type II endoleaks in infrarenal endovascular aneurysm repair based on the ENGAGE registry data. J Vasc Surg 71(3):780-789. https://doi.org/10.1016/j.jvs.2019.04.486. Fujii T, Banno H, Kodama A, Sugimoto M, Akita N, Tsuruoka T, Sakakibara M, Komori K (2020) Aneurysm Sac Thrombus Volume Predicts Aneurysm Expansion with Type II Endoleak After Endovascular Aneurysm Repair. Ann Vasc Surg 66:85-94.e81. https://doi.org/10.1016/j.avsg.2019.11.045. Gelfand DV, White GH, Wilson SE (2006) Clinical significance of type II endoleak after endovascular repair of abdominal aortic aneurysm. Ann Vasc Surg 20(1):69-74. https://doi.org/10.1007/s10016-005-9382-z. Gonzalez-Urquijo M, Lozano-Balderas G, Fabiani MA (2020) Type II Endoleaks After EVAR: A Literature Review of Current Concepts. Vasc Endovascular Surg 54(8):718-724. https://doi.org/10.1177/1538574420945448. Guo Q, Zhao J, Ma Y, Huang B, Yuan D, Yang Y, Du X (2020) A meta-analysis of translumbar embolization versus transarterial embolization for type II endoleak after endovascular repair of abdominal aortic aneurysm. J Vasc Surg 71(3):1029-1034.e1021. https://doi.org/10.1016/j.jvs.2019.05.074. Horinouchi H, Okada T, Yamaguchi M, Maruyama K, Sasaki K, Gentsu T, Ueshima E, Sofue K, Kawasaki R, Nomura Y, Omura A, Okada K, Sugimoto K, Murakami T (2020) Mid-term Outcomes and Predictors of Transarterial Embolization for Type II Endoleak After Endovascular Abdominal Aortic Aneurysm Repair. Cardiovasc Intervent Radiol 43(5):696-705. https://doi.org/10.1007/s00270-020-02436-2. Iwakoshi S, Ogawa Y, Dake MD, Ono Y, Higashihara H, Ikoma A, Nakai M, Taniguchi T, Ogi T, Kawada H, Tamura A, Ieko Y, Tanaka R, Sohgawa E, Nagatomi S, Woodhams R, Ikeda O, Mori K, Nishimaki H, Koizumi J, Senokuchi T, Hagihara M, Shimohira M, Takasugi S, Imaizumi A, Higashiura W, Sakaguchi S, Ichihashi S, Inoue T, Inoue T, Kichikawa K (2023) Outcomes of embolization procedures for type II endoleaks following endovascular abdominal aortic repair. J Vasc Surg 77(1):114-121.e112. https://doi.org/10.1016/j.jvs.2022.07.168. Jones JE, Atkins MD, Brewster DC, Chung TK, Kwolek CJ, LaMuraglia GM, Hodgman TM, Cambria RP (2007) Persistent type 2 endoleak after endovascular repair of abdominal aortic aneurysm is associated with adverse late outcomes. J Vasc Surg 46(1):1-8. https://doi.org/10.1016/j.jvs.2007.02.073. Karthikesalingam A, Thrumurthy SG, Jackson D, Choke E, Sayers RD, Loftus IM, Thompson MM, Holt PJ (2012) Current evidence is insufficient to define an optimal threshold for intervention in isolated type II endoleak after endovascular aneurysm repair. J Endovasc Ther 19(2):200-208. https://doi.org/10.1583/11-3762r.1. Kasirajan K, Matteson B, Marek JM, Langsfeld M (2003) Technique and results of transfemoral superselective coil embolization of type II lumbar endoleak. J Vasc Surg 38(1):61-66. https://doi.org/10.1016/s0741-5214(02)75467-0. Lederle FA, Freischlag JA, Kyriakides TC, Padberg FT, Jr., Matsumura JS, Kohler TR, Lin PH, Jean-Claude JM, Cikrit DF, Swanson KM, Peduzzi PN (2009) Outcomes following endovascular vs open repair of abdominal aortic aneurysm: a randomized trial. Jama 302(14):1535-1542. https://doi.org/10.1001/jama.2009.1426. Mewissen MW, Jan MF, Kuten D, Krajcer Z (2017) Laser-Assisted Transgraft Embolization: A Technique for the Treatment of Type II Endoleaks. J Vasc Interv Radiol 28(11):1600-1603. https://doi.org/10.1016/j.jvir.2017.07.029. Nana P, Spanos K, Heidemann F, Panuccio G, Kouvelos G, Rohlffs F, Giannoukas A, Kölbel T (2022) Systematic review on transcaval embolization for type II endoleak after endovascular aortic aneurysm repair. J Vasc Surg 76(1):282-291.e282. https://doi.org/10.1016/j.jvs.2022.02.032. Prinssen M, Verhoeven EL, Buth J, Cuypers PW, van Sambeek MR, Balm R, Buskens E, Grobbee DE, Blankensteijn JD (2004) A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms. N Engl J Med 351(16):1607-1618. https://doi.org/10.1056/NEJMoa042002. Sarac TP, Gibbons C, Vargas L, Liu J, Srivastava S, Bena J, Mastracci T, Kashyap VS, Clair D (2012) Long-term follow-up of type II endoleak embolization reveals the need for close surveillance. J Vasc Surg 55(1):33-40. https://doi.org/10.1016/j.jvs.2011.07.092. Seike Y, Matsuda H, Shimizu H, Ishimaru S, Hoshina K, Michihata N, Yasunaga H, Komori K (2022) Nationwide Analysis of Persistent Type II Endoleak and Late Outcomes of Endovascular Abdominal Aortic Aneurysm Repair in Japan: A Propensity-Matched Analysis. Circulation 145(14):1056-1066. https://doi.org/10.1161/circulationaha.121.056581. Spanos K, Nana P, Behrendt CA, Kouvelos G, Panuccio G, Heidemann F, Matsagkas M, Debus S, Giannoukas A, Kölbel T (2020) Management of Abdominal Aortic Aneurysm Disease: Similarities and Differences Among Cardiovascular Guidelines and NICE Guidance. J Endovasc Ther 27(6):889-901. https://doi.org/10.1177/1526602820951265. Ultee KHJ, Büttner S, Huurman R, Bastos Gonçalves F, Hoeks SE, Bramer WM, Schermerhorn ML, Verhagen HJM (2018) Editor's Choice - Systematic Review and Meta-Analysis of the Outcome of Treatment for Type II Endoleak Following Endovascular Aneurysm Repair. Eur J Vasc Endovasc Surg 56(6):794-807. https://doi.org/10.1016/j.ejvs.2018.06.009. Walker J, Tucker LY, Goodney P, Candell L, Hua H, Okuhn S, Hill B, Chang RW (2015) Type II endoleak with or without intervention after endovascular aortic aneurysm repair does not change aneurysm-related outcomes despite sac growth. J Vasc Surg 62(3):551-561. https://doi.org/10.1016/j.jvs.2015.04.389. Yu H, Desai H, Isaacson AJ, Dixon RG, Farber MA, Burke CT (2017) Comparison of Type II Endoleak Embolizations: Embolization of Endoleak Nidus Only versus Embolization of Endoleak Nidus and Branch Vessels. J Vasc Interv Radiol 28(2):176-184. https://doi.org/10.1016/j.jvir.2016.10.002. Supplementary Files SFigure1.docx Supplemental Figure 1. Illustrative examples of indirect transarterial embolization. A: Although it reached the nidus, a digital subtraction angiography image suggested that injection of N-butyl cyanoacrylate glue would likely cause reflux (white arrow). B: Only coiling of the lumbar artery (white arrow) was performed. C: Dynamic CT scan immediately before embolization. D: For 3.3 years, the diameter of the aorta increased by > 5 mm, as observed in a dynamic CT scan. 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-4159651","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":287375908,"identity":"2a3d9ea4-f558-4840-a2a9-419590912efb","order_by":0,"name":"Kenichiro Okumura","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0001-8131-7584","institution":"Kanazawa University Graduate School of Medical Sciences: Kanazawa Daigaku Daigakuin Iyaku Hokengaku Sogo Kenkyuka Iyaku Hoken Gakuiki Igakurui","correspondingAuthor":true,"prefix":"","firstName":"Kenichiro","middleName":"","lastName":"Okumura","suffix":""},{"id":287375909,"identity":"76ddb176-95ce-41cd-852f-f811468fd598","order_by":1,"name":"Takahiro Ogi","email":"","orcid":"https://orcid.org/0000-0001-9999-1278","institution":"Kanazawa University Graduate School of Medical Sciences: Kanazawa Daigaku Daigakuin Iyaku Hokengaku Sogo Kenkyuka Iyaku Hoken Gakuiki Igakurui","correspondingAuthor":false,"prefix":"","firstName":"Takahiro","middleName":"","lastName":"Ogi","suffix":""},{"id":287375910,"identity":"3cf9bfc4-5ad1-498b-a2c5-e464d5d7fe4e","order_by":2,"name":"Junichi Matsumoto","email":"","orcid":"","institution":"Kanazawa University Graduate School of Medical Sciences: Kanazawa Daigaku Daigakuin Iyaku Hokengaku Sogo Kenkyuka Iyaku Hoken Gakuiki Igakurui","correspondingAuthor":false,"prefix":"","firstName":"Junichi","middleName":"","lastName":"Matsumoto","suffix":""},{"id":287375911,"identity":"d5fb4458-ee33-4c33-9a3c-70b08f6680cd","order_by":3,"name":"Nobuyuki Asato","email":"","orcid":"","institution":"Kanazawa University Graduate School of Medical Sciences: Kanazawa Daigaku Daigakuin Iyaku Hokengaku Sogo Kenkyuka Iyaku Hoken Gakuiki Igakurui","correspondingAuthor":false,"prefix":"","firstName":"Nobuyuki","middleName":"","lastName":"Asato","suffix":""},{"id":287375912,"identity":"6827e45f-2a9c-4088-8460-c3b04878c330","order_by":4,"name":"Takumi Sugiura","email":"","orcid":"","institution":"Fukui Prefectural Hospital: Fukui Kenritsu Byoin","correspondingAuthor":false,"prefix":"","firstName":"Takumi","middleName":"","lastName":"Sugiura","suffix":""},{"id":287375913,"identity":"49d59470-e76e-4c5a-a484-12bf72933fe4","order_by":5,"name":"Akira Yokka","email":"","orcid":"","institution":"Fukui-ken Saiseikai Hospital: Fukui-ken Saiseikai Byoin","correspondingAuthor":false,"prefix":"","firstName":"Akira","middleName":"","lastName":"Yokka","suffix":""},{"id":287375914,"identity":"667fbe55-3130-4d85-ba2d-18ca792c73db","order_by":6,"name":"Kazuto Kozaka","email":"","orcid":"","institution":"Kanazawa University Graduate School of Medical Sciences: Kanazawa Daigaku Daigakuin Iyaku Hokengaku Sogo Kenkyuka Iyaku Hoken Gakuiki Igakurui","correspondingAuthor":false,"prefix":"","firstName":"Kazuto","middleName":"","lastName":"Kozaka","suffix":""},{"id":287375915,"identity":"099a4aab-d14c-40f2-b2d9-25a3058f385a","order_by":7,"name":"Satoshi Kobayashi","email":"","orcid":"","institution":"Kanazawa University Graduate School of Medical Sciences: Kanazawa Daigaku Daigakuin Iyaku Hokengaku Sogo Kenkyuka Iyaku Hoken Gakuiki Igakurui","correspondingAuthor":false,"prefix":"","firstName":"Satoshi","middleName":"","lastName":"Kobayashi","suffix":""}],"badges":[],"createdAt":"2024-03-24 22:47:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4159651/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4159651/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":54448659,"identity":"1f866f7a-d62b-4e44-8932-4e6d4cff4201","added_by":"auto","created_at":"2024-04-10 17:24:31","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1032536,"visible":true,"origin":"","legend":"\u003cp\u003eIllustrative examples of uniform, well-defined type II and moyamoya endoleaks.\u003c/p\u003e\n\u003cp\u003eA, Type II endoleak originating from the lumbar artery. The endoleak opacity is homogeneous, with a clearly defined edge on dynamic CT imaging. This type of type II endoleak exhibits uniform and well-defined characteristics. B, During the digital subtraction angiography, contrast agent flow within a large cavity can be observed.\u003c/p\u003e\n\u003cp\u003eC, Type II endoleak supplied from the inferior mesenteric artery. The endoleak opacity was heterogeneous with a faint and ill-defined edge. This type of endoleak is defined as a Moyamoya endoleak. D, During the digital subtraction angiography, the contrast agent infiltrating through the gaps in the thrombus can be observed.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4159651/v1/39d0a0dad245ad92a965e084.jpeg"},{"id":54448660,"identity":"f76bf311-e5ac-476a-bf73-a0fda682037f","added_by":"auto","created_at":"2024-04-10 17:24:31","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":222875,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan–Meier curve revealing freedom from aneurysm expansion following embolization in 40 patients.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4159651/v1/3e0f91ea72ff3bba41c06e13.jpeg"},{"id":54448661,"identity":"7aedd211-be45-4338-9c60-02f9b935bf8a","added_by":"auto","created_at":"2024-04-10 17:24:31","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":270676,"visible":true,"origin":"","legend":"\u003cp\u003eComparing sac enlargement freedom rates across three methods.\u003c/p\u003e\n\u003cp\u003eThe rate of freedom from sac enlargement is compared among three nidus and branch embolization methods: direct transarterial embolization using coils with or without NBCA glue, direct transarterial embolization using NBCA glue only, and indirect transarterial embolization. The insertion of the catheter into the nidus via the arterial route followed by transarterial embolization defined as direct transarterial embolization. On the other hand, procedures that do not directly embolize the nidus are defined as indirect transarterial embolization. Kaplan–Meier curve comparing the freedom from sac enlargement rates among the three embolization methods: direct embolization using coils with or without NBCA glue, direct embolization using NBCA glue only, and indirect embolization. TAE, transarterial embolization; NBCA, N-butyl-2-cyanoacrylate\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4159651/v1/947c1c0631a29f6b53081561.jpeg"},{"id":54448662,"identity":"b764cdf5-d895-47dc-ac13-67f9100a7474","added_by":"auto","created_at":"2024-04-10 17:24:31","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":924693,"visible":true,"origin":"","legend":"\u003cp\u003eIllustrative examples of direct transarterial embolization with coils and N-butyl cyanoacrylate glue.\u003c/p\u003e\n\u003cp\u003eA: The nidus was reached and a digital subtraction angiography image was acquired. The nidus (white arrow) was visualized. B: After embolization, N-butyl cyanoacrylate glue remained in the nidus and coils in the lumbar and inferior mesenteric arteries (white arrow). C: An endoleak is observed in the CT image before embolization (black arrow). D: In the CT scan performed 5.4 years later, the N-butyl cyanoacrylate glue was still visible (black arrow), and there was no observed increase in the aneurysm diameter.\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4159651/v1/fea3806af3239c7620f41153.jpeg"},{"id":54448664,"identity":"1f753f5b-bda7-47f1-80ed-7662a7b6d170","added_by":"auto","created_at":"2024-04-10 17:24:31","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1118552,"visible":true,"origin":"","legend":"\u003cp\u003eIllustrative examples of direct transarterial embolization with N-butyl cyanoacrylate glue.\u003c/p\u003e\n\u003cp\u003eA: The nidus was reached and a digital subtraction angiography image was acquired. The nidus (white arrow) and its branches (lumbar artery; black arrow) were visualized. B: After injecting N-butyl cyanoacrylate glue, the glue flowed into the nidus and branches, where it remained. C: In the CT scan performed immediately after embolization, the glue remains in the nidus (black arrow), and no endoleak was observed. D: In the CT scan performed 1.5 years later, the N-butyl cyanoacrylate glue was dissipated (black arrow), and an increase in aneurysm diameter was observed.\u003c/p\u003e","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4159651/v1/315c578efdb9af71823f8628.jpeg"},{"id":54449838,"identity":"0b3ea6ca-540a-4ca4-a20f-d5349e5e13ff","added_by":"auto","created_at":"2024-04-10 17:40:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1317413,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4159651/v1/3381a61d-3b11-46de-8ae8-ded350cd7c97.pdf"},{"id":54448663,"identity":"3506ec29-8b64-4efb-83e7-9b68ccfcfdbe","added_by":"auto","created_at":"2024-04-10 17:24:31","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":5080623,"visible":true,"origin":"","legend":"\u003cp\u003eSupplemental Figure 1. Illustrative examples of indirect transarterial embolization.\u003c/p\u003e\n\u003cp\u003eA: Although it reached the nidus, a digital subtraction angiography image suggested that injection of N-butyl cyanoacrylate glue would likely cause reflux (white arrow). B: Only coiling of the lumbar artery (white arrow) was performed. C: Dynamic CT scan immediately before embolization. D: For 3.3 years, the diameter of the aorta increased by \u0026gt; 5 mm, as observed in a dynamic CT scan.\u003c/p\u003e","description":"","filename":"SFigure1.docx","url":"https://assets-eu.researchsquare.com/files/rs-4159651/v1/fc0e523f96089f96114b08b8.docx"}],"financialInterests":"","formattedTitle":"Transarterial Embolization of Type 2 Endoleak Using Coils and N-Butyl Cyanoacrylate: The Importance of Treating the Nidus and Sac Branches","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eEndovascular abdominal aortic aneurysm repair (EVAR) has gained global popularity as a preferred treatment option due to its lower perioperative mortality and complications than those of surgery (2005; Lederle et al. 2009; Prinssen et al. 2004). However, the most prevalent post-EVAR complication is known as type 2 endoleak (T2EL), occurring in 8\u0026ndash;44% of patients following EVAR (Chaikof et al. 2018; Choke and Thompson 2004; D'Oria et al. 2020; Gelfand et al. 2006; Jones et al. 2007; Spanos et al. 2020). Although T2EL is generally considered a benign complication, it carries a potential risk of sac expansion and rupture (Deery et al. 2018; Jones et al. 2007; Seike et al. 2022). The natural history and treatment of T2EL remain subject to ongoing debate (Gonzalez-Urquijo et al. 2020). Typically, T2EL is typically managed conservatively, as many cases resolve spontaneously (Dijkstra et al. 2020; Jones et al. 2007; Walker et al. 2015). Various methods of embolizing T2EL have been documented (Chen and Stavropoulos 2020). While transarterial embolization (TAE) is a minimally invasive option, systematic reviews and meta-analyses indicate that its effectiveness is variable and not consistently superior to conservative treatments (Karthikesalingam et al. 2012; Sarac et al. 2012; Ultee et al. 2018).\u003c/p\u003e \u003cp\u003eHowever, previous studies have yielded inconclusive regarding the relationship between the embolic material and the detailed levels of embolization. Moreover, existing evidence might underestimate the efficacy of additional treatment for persistent T2EL. In a recent multicenter study, moyamoya endoleak, a hard-to-embolize nidus, was identified as a predictor of reduced efficacy of TAE (Iwakoshi et al. 2023). Considering these perspectives, conducting comprehensive medium- to long-term evaluations and large-scale studies that address the procedural intricacies is crucial.\u003c/p\u003e \u003cp\u003eTherefore, the purpose of this study is to compare the mid-term outcomes of embolizing both the endoleak nidus and branches versus the branches alone in preventing aneurysm sac enlargement following T2EL. Secondary to this, the study evaluates the impact of different embolic materials used in these procedures.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients\u003c/h2\u003e \u003cp\u003e The institutional review board approved this retrospective cohort study, and the need for informed consent was waived. A review of the medical records and imaging studies was conducted for consecutive 59 patients who underwent TAE for type II endoleak between September 2017 and August 2022. Data from before the stent graft implantation was utilized as the medical record. One patient with Marfan syndrome and another with infection were excluded. Eleven patients with \u0026lt;\u0026thinsp;6 months of follow-up duration and six without abdominal aortic aneurysm (AAA) were excluded.\u003c/p\u003e \u003cp\u003eTechnical success was defined as the absence of detectable endoleaks during the completion angiogram at TAE (Details of technical success are available in the next section). No patient had concurrent endoleak types other than T2EL. Overall, 40 patients (31 men and 9 women, median age, 80 years [interquartile ranges (IQR) 75\u0026ndash;85) years] who underwent TAE for T2EL following EVAR were enrolled. The decision to perform TAE for T2EL after EVAR was based on the presence of persistent T2EL with sac enlargement of \u0026gt;\u0026thinsp;5 mm in all cases.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eTAE Procedure\u003c/h2\u003e \u003cp\u003eThe treatment strategy involves successful catheter advancement and embolization of the endoleak nidus and main feeding or drainage branches. In this study, the term \"direct TAE\" refers to the insertion of the catheter into the nidus via the arterial route followed by transarterial embolization. And, indirect TAE is defined as procedures that do not directly embolize the nidus. During angiography, when drainage branches from the endoleak nidus in the aneurysm were identified, these branches were selected and embolized with coils. Subsequently, embolization of the endoleak nidus and feeding branches was performed sequentially. The endoleak nidus and its associated branches were embolized using N-butyl-2-cyanoacrylate (NBCA) glue or coils. Indirect embolization refers to the practice of embolizing the main branches when it is not feasible to access the endoleak nidus or when the endoleak nidus is too small to accommodate the use of liquid embolization material without the risk of reflux. The patent aortic branches connecting to the endoleak nidus serving as feeding or drainage arteries for T2EL were identified through preprocedural contrast-enhanced computed tomography (CT) scans, with a slice thickness of 0.63-mm to 1.25-mm and angiograms conducted during the TAE procedure. The presence of coexisting endoleak types, other than T2EL, was checked utilizing the preprocedural contrast-enhanced CT scans and intraoperative angiograms.\u003c/p\u003e \u003cp\u003eTo address T2EL originating from the inferior mesenteric artery (IMA), accesse was gained to the middle colic artery through the superior mesenteric artery. The IMA was then cannulated via the arc of Riolan or the marginal artery. To address T2EL originating from the lumbar artery, the iliolumbar arteries were accessed via the internal iliac arteries, followed by retrograde cannulation of the lumbar artery.\u003c/p\u003e \u003cp\u003eA 1.9-Fr non-tapered microcatheter (Carnelian MARVEL NT; Tokai Medical Product, Aichi, Japan) was advanced to the endoleak nidus through a 2.9-Fr microcatheter (Leonis Mova; SB Kawasumi, Kanagawa, Japan), coaxially introduced through a 4\u0026ndash;5-Fr catheter. The embolization was performed using coils and NBCA glue. Specifically, coil embolization was performed using hydrogel-coated coils (Azur Soft 3D; Terumo, Tokyo, Japan) or detachable non-fibered coils (ED and i-ED COIL; Kaneka, Osaka, Japan). NBCA glue consists of a mixture of N-butyl-2-cyanoacrylate (Histoacryl; B.Braun, Melsungen, Germany) and iodized oil (Lipiodol; Guerbet, Aulnay-sous-Bois, France). The attending interventional radiologist determined the selection of embolization materials and the specified NBCA/Lipiodol ratio (16\u0026ndash;50%) based on the target vessel anatomy. It was defined that successful embolization using coils and NBCA glue was achieved when the nidus was completely occluded by coils and NBCA glue, or if the nidus was embolized with NBCA glue, up to two associated branches could be successfully occluded using coils on the initial emobolization. If the embolization using coils and NBCA glue did not success, the procedure was classified as an embolization using only NBCA glue; this was observed in only three cases, where the concentration of NBCA glue used ranged from 16\u0026ndash;25%. The procedural endpoint (technical success) was the absence of remarkably detectable endoleak nidus during the completion angiogram. No patients with substantial residual nidus during the completion angiogram were included in this study. The results and specific details of the TAE procedures were collected from the operative reports.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eFollow-up protocol\u003c/h2\u003e \u003cp\u003eFollowing the initial TAE, unenhanced CT scans were routinely performed at 1, 6, and 12 months, with subsequent annual scans if no sac enlargement was identified. Contrast-enhanced CT scans were conducted when sac enlargement, stent-graft migration, or sealing-zone shortening was identified. However, contrast media administration was avoided in patients with renal dysfunction or contrast medium intolerance.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eImaging Outcomes\u003c/h2\u003e \u003cp\u003eTwo radiologists with 10\u0026ndash;20 years of experience conducted preprocedural and follow-up evaluations using CT scans and conventional angiograms, blind to the outcomes. Consensus was reached to resolve all discrepancies. The assessment included the measurement of the maximum aneurysmal sac diameter, moyamoya endoleak (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), determination of endoleak presence and type. A Moyamoya endoleak was defined by its heterogeneous opacity with a faint and ill-defined edge. The final diagnosis was reached through a consensus. Maximum aneurysmal sac diameter was defined as the external diameter in the axial images. Aneurysmal sac enlargement was defined as a\u0026thinsp;\u0026gt;\u0026thinsp;5mm increase in the maximum diameter compared to the sac diameter during the initial TAE.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003ePredictors of Sac Enlargement After TAE for T2EL\u003c/h2\u003e \u003cp\u003ePatient characteristics and clinical factors were evaluated to investigate their potential association with sac enlargement following TAE. These included preprocedural demographics, clinical characteristics, smoking status, history of antiplatelet and anticoagulant use, and the type of EVAR device used. Others include aneurysmal sac diameter at the time of EVAR and initial TAE, the interval and sac growth between EVAR and initial TAE, follow-up duration following TAE, the number of patent aortic branches at the initial TAE, and the procedures of embolization. The embolization procedures were categorized into three groups as follows: direct TAE involving the nidus and its associated branches using coils incorporating NBCA glue as needed; direct TAE incorporating the nidus and its associated branches, utilizing only NBCA glue; and indirect TAE of associated branches, without nidus packing, using both coils incorporating NBCA glue as needed. There have been no cases where the nidus has been embolized with coils followed by embolization of the branches with NBCA glue.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eIn cases of missing data or loss to follow-up, the last observation carried forward method was employed to impute missing values. Categorical variables were summarized using frequencies and percentages, while continuous variables were expressed using median and interquartile ranges. Fisher\u0026rsquo;s exact test was utilized to analyze clinical and TAE features (categorical variables). The Mann\u0026ndash;Whitney test was used to analyze age, sac diameter, and the interval between EVAR and the first TAE. The Kaplan\u0026ndash;Meier curve was utilized to estimate freedom from sac enlargement and reintervention rate, while the log-rank test was used for comparison. Statistical analyses were performed using GraphPad Software (Version 9.5.1 for Mac, San Diego, USA). A P value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eTAE Technique\u003c/h2\u003e \u003cp\u003eAll patients exhibited attenuation of the nidus on the completion angiogram following TAE. Of these, 60% (n\u0026thinsp;=\u0026thinsp;24) underwent embolization via direct cannulation to the nidus. In comparison, for the remaining 40% (n\u0026thinsp;=\u0026thinsp;16), even if access to the nidus was achieved, embolization of the nidus itself was challenging, so embolization was performed on the branches directly connected to the nidus, targeting as many involved branches as possible. Among the patients who underwent nidus cannulation, 53% (n\u0026thinsp;=\u0026thinsp;21) were embolized using a combination of coils and NBCA glue, while the remaining 7% (n\u0026thinsp;=\u0026thinsp;3) were embolized solely with NBCA glue (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\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\u003ePatient demographics, comorbidities and results of transarterial embolization procedure.\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=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAll, n\u0026thinsp;=\u0026thinsp;40\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80 (76\u0026ndash;85)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMale sex\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31 (78)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCoronary artery disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDiabetes mellitus\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eChronic kidney disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHypertension\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37 (93)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDyslipidemia\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29 (73)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePeripheral artery disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSmoking\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCurrent\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFormer\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23 (58)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNever\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (35)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAnticoagulation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAntiplatlet\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24 60)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSac diameter at EVAR, mm\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e51 (45\u0026ndash;56)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSac diameter at 1st TAE, mm\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57 (51\u0026ndash;62)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEVAR device\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eExcluder\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25 (63)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eZenith\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEndurant\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11 (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAFX\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSac enlargement\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (35)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eInterval between EVAR and 1st TAE, m\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e41 (30\u0026ndash;69)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFollow up duration after 1st TAE, y\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.7 (0.9\u0026ndash;2.8)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNumber of patent aortic branches at 1st TAE\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 (38)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13 (32)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNumber of cases requiring 2 or more TAE\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13 (33)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEmbolization location\u003c/b\u003e* \u003cb\u003e(material)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNidus and branches\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24 (60)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e(Coil with/without NBCA glue)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21 (53)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e(Only NBCA glue)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBranches without nidus\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003e(NBCA glue or Coil)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16 (40)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eNote.- Data are presented as counts (percentages) for the categorical variables or median (interquartile ranges) for the continuous variables. *Embolization procedures were classified based on whether the nidus was embolized and the type of embolic material used: either NBCA glue only or a combination of coils and NBCA glue as needed. There have been no cases where the nidus has been embolized with coils followed by embolization of the branches with NBCA glue. EVAR, endovascular abdominal aortic aneurysm repair; TAE, transarterial embolization; NBCA, N-butyl-2-cyanoacrylate.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eImaging Outcomes\u003c/h2\u003e \u003cp\u003eThe median sac diameter at the time of EVAR was 51 mm (IQR: 45\u0026ndash;56), while the median sac diameter at the first TAE was 57 mm (IQR: 51\u0026ndash;62). In 33% of patients (n\u0026thinsp;=\u0026thinsp;13), two or more TAE procedures were required. Sac enlargement of \u0026gt;\u0026thinsp;5 mm following TAE was observed in 35% of patients (n\u0026thinsp;=\u0026thinsp;14). The sac non-enlargement rates at 1, 3, and 5 years were 93%, 68%, and 65%, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eClinical Outcomes\u003c/h2\u003e \u003cp\u003eThe median follow-up period was 1.7 years (IQR: 0.9\u0026ndash;2.8 years) after the first TAE. Among the patients who underwent direct TAE for nidus and branches using a coil with or without NBCA glue (n\u0026thinsp;=\u0026thinsp;24, 60%), the rates of sac non-expansion were 100%, 95%, and 95% at 1, 3, and 5 years, respectively (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). In all patients (n\u0026thinsp;=\u0026thinsp;3, 100%) in whom nidus with branches embolized exclusively using NBCA glue, sac enlargement was observed within 2 years, and the NBCA glue had disappeared in the images (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). For patients who underwent embolization specifically for branches without direct TAE of the endoleak nidus (n\u0026thinsp;=\u0026thinsp;16, 40%) (Supplemental Fig.\u0026nbsp;1), the rates of remaining free from sac enlargement were 81%, 44%, and 38% at 1, 3, and 5 years, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eFactors Related to Moyamoya Endoleak\u003c/h2\u003e \u003cp\u003eIn the group with moyamoya endoleak, a higher percentage of patients were administered antiplatelet medication than those without it (14 [82%] vs. 10 [43%], p\u0026thinsp;=\u0026thinsp;0.02). The interval between EVAR and the first TAE was relatively longer in the group with moyamoya endoleak (52 days, IQR: 31\u0026ndash;78) than in the group without it (37 days, IQR: 26\u0026ndash;54). However, this difference was not statistically significant (p\u0026thinsp;=\u0026thinsp;0.07). Moyamoya endoleak occurred significantly less frequently in the group that underwent direct TAE using coils, incorporating NBCA glue as needed (29%, n\u0026thinsp;=\u0026thinsp;5), than in the opposite group (70%, n\u0026thinsp;=\u0026thinsp;16, p\u0026thinsp;=\u0026thinsp;0.02). Moyamoya endoleak was more prevalent in the group where direct TAE of the nibus could not be performed (59%, n\u0026thinsp;=\u0026thinsp;10) than in the group without direct TAE (26%, n\u0026thinsp;=\u0026thinsp;6). Nevertheless, the difference was insignificant (p\u0026thinsp;=\u0026thinsp;0.053, Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\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\u003eUnivariate comparison of factors associated with Moyamoya endoleak.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eMoyamoya Endoleak\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes n\u0026thinsp;=\u0026thinsp;17\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNo n\u0026thinsp;=\u0026thinsp;23\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e84 (78\u0026ndash;86)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79 (74\u0026ndash;83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMale sex\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13 (76)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18 (78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCoronary artery disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDiabetes mellitus\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eChronic kidney disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHypertension\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17 (100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20 (87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDyslipidemia\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 (88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (61)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePeripheral artery disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSmoking\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCurrent\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFormer\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (57)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNever\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAnticoagulation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAntiplatlet\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (8\u003cb\u003e2\u003c/b\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSac diameter at EVAR, mm\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50 (45\u0026ndash;55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e53 (43\u0026ndash;58)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.54\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSac diameter at 1st TAE, mm\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e56 (53\u0026ndash;58)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58 (49\u0026ndash;62)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.72\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEVAR device\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eExcluder\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (71)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (57)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.51\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eZenith\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEndurant\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAFX\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSac enlargement\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (47)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eInterval between EVAR and 1st TAE, m\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52 (31\u0026ndash;78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37 (26\u0026ndash;54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNumber of patent aortic branches at 1st TAE\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.75\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNumber of cases requiring 2 or more TAE\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.49\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEmbolization location* (material)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNidus with branches\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e(Coil with/without NBCA glue)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16 (70)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e(Only NBCA glue)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBranches without nidus\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003e(NBCA glue or Coil)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.053\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eNote. - Data are presented as counts (percentages) for the categorical variables or median (interquartile ranges) for the continuous variables.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e*Embolization procedures were classified based on whether the nidus was embolized and the type of embolic material used: either NBCA glue only or a combination of coils and NBCA glue as needed. There have been no cases where the nidus has been embolized with coils followed by embolization of the branches with NBCA glue. EVAR, endovascular abdominal aortic aneurysm repair; TAE, transarterial embolization; NBCA, N-butyl-2-cyanoacrylate.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eFactors Contributing to Sac Enlargement after TAE for T2EL\u003c/h2\u003e \u003cp\u003eWe analyzed 28 factors associated with sac enlargement of \u0026gt;\u0026thinsp;5 mm following TAE. Univariate analysis revealed that variables associated with sac enlargement (those with P values\u0026thinsp;\u0026lt;\u0026thinsp;0.05) included the specific procedures (embolization with NBCA glue only and TAE for branches without nidus) and two or more TAE procedures (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Among the 14 patients who experienced sac enlargement, direct nidus TAE was unsuccessful in 10 (72%) (p\u0026thinsp;=\u0026thinsp;0.006). Conversely, among the group of 26 patients who did not experience sac enlargement, 20 (77%) underwent successful embolization of the nidus and main branch using coils, incorporating NBCA glue as needed (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Furthermore, sac enlargement was observed in three patients who, despite having undergone successful direct TAE of the nidus and branches, were exclusively embolized with NBCA glue (p\u0026thinsp;=\u0026thinsp;0.04).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eUnivariate comparison of factors associated with sac enlargement.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eSac enlargement\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes n\u0026thinsp;=\u0026thinsp;14\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNo n\u0026thinsp;=\u0026thinsp;26\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e82 (76\u0026ndash;84)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79 (74\u0026ndash;83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMale sex\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11 (79)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20 (77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.69\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCoronary artery disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDiabetes mellitus\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.41\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eChronic kidney disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHypertension\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (86)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25 (96)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.47\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDyslipidemia\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (64)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20 (77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.69\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePeripheral artery disease\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSmoking\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCurrent\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.52\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFormer\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16 (62)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNever\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.32\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAnticoagulation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAntiplatlet\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (71)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSac diameter at EVAR, mm\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e51 (48\u0026ndash;56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e50 (44\u0026ndash;57)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.53\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSac diameter at 1st TAE, mm\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57 (55\u0026ndash;63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57 (49\u0026ndash;62)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.46\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEVAR device\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eExcluder\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11 (79)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eZenith\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEndurant\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9 (35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAFX\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.53\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eInterval between EVAR and 1st TAE, m\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42 (26\u0026ndash;75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40 (30\u0026ndash;60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.81\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNumber of patent aortic branches at 1st TAE\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12 (46)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (36)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.53\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNumber of cases requiring 2 or more TAE\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (57)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEmbolization location\u003c/b\u003e* \u003cb\u003e(material)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNidus and branches\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e(Coil with/without NBCA glue)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20 (77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e(Only NBCA glue)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBranches without nidus\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003e(NBCA glue or Coil)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eData are presented as counts (percentages) for the categorical variables or median (interquartile ranges) for the continuous variables.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e* Embolization procedures were classified based on whether the nidus was embolized and the type of embolic material used: either NBCA glue only or a combination of coils and NBCA glue as needed. There have been no cases where the nidus has been embolized with coils followed by embolization of the branches with NBCA glue. EVAR endovascular abdominal aortic aneurysm repair; TAE, transarterial embolization; NBCA, N-butyl-2-cyanoacrylate.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis study investigated the results of embolization methods applied to T2EL after EVAR. The results highlighted the significant impact on sac diameter when successful direct TAE of both the nidus and its associated branches was achieved. Furthermore, apart from previously reported risk factors for sac enlargement, there was a notable correlation between direct embolization techniques, using coils and incorporating NBCA glue as needed, and sac enlargement. Among patients who underwent successful direct TAE, the rates of sac non-expansion were 100%, 95%, and 95% at 1, 3, and 5 years, respectively.\u003c/p\u003e \u003cp\u003ePrevious reports suggested that sac diameter before embolization influenced the embolic effect of TAE (Horinouchi et al. 2020). Contrary to the findings in those reports, this study revealed that successful direct TAE of the nidus and branches, with the adjunctive use of coils and as-needed NBCA glue, was the critical factor influencing sac diameter reduction. A history of dyslipidemia and the use of antiplatelet medications are associated with multiple embolization procedures, and smoking and the presence of a moyamoya nidus, characterized by unclear boundaries, were known factors that weaken the effect of TAE on the inhibition of sac diameter increase (Charitable et al. 2021; Iwakoshi et al. 2023; Sarac et al. 2012). The larger the thrombus volume in the sac, the more effectively it inhibited the increase in sac diameter (Fujii et al. 2020). The results of the current study suggest that moyamoya endoleak is associated with the use of antiplatelet agents, suggesting that inadequate thrombosis of the aneurysm may lead to moyamoya endoleak. Although achieving effective embolization in the presence of moyamoya endoleak is challenging (Iwakoshi et al. 2023), it is speculated that the antiplatelets effects, in addition to the small size of the nidus making it difficult to embolize, may contribute to the reduced efficacy of the embolization process.\u003c/p\u003e \u003cp\u003eAnd then, based on the results of this study, two important technical factors in endoleak embolization were identified, the first being direct nidus embolization. This was consistent with many reports indicating the usefulness of embolization via direct puncture of the nidus (Guo et al. 2020; Mewissen et al. 2017; Nana et al. 2022). Furthermore, in some reports, embolization of the branch was not always necessary if the nidus was properly embolized (Yu et al. 2017). In a meta-analysis, it was observed that direct puncture embolization of the nidus achieved a higher clinical success rate than TAE. This difference in clinical success could be attributed to variations in the rate of embolization directly to the nidus (Guo et al. 2020). In contrast, embolization of the branch alone increased sac diameter even when the endoleak was properly embolized (Sarac et al. 2012). This finding was consistent with the conclusion that proper nidus embolization was necessary. The study also found that embolization of only the branches was less effective than direct TAE of the nidus and branches in preventing sac enlargement, even if the embolization was performed at a level directly connected to the nidus. These results supported that direct TAE of nidus and branches was an important technical component in endoleak embolization.\u003c/p\u003e \u003cp\u003eAnother important consideration was using coils for embolization to prevent loss of embolic material in the nidus. TAE with liquid embolic material was reported as a useful tool for the embolization of T2EL. However, it is essential to note that these reports had a limited follow-up period of only 2 years (Abularrage et al. 2012). Also, TAE involving the nidus and branches using coils has been documented as beneficial. However, the particular report had a relatively short follow-up period of approximately 1 year (Kasirajan et al. 2003). This study revealed that embolizing branches exclusively with NBCA glue resulted in a statistically significant increase in sac diameter while using coils in the embolization of the nidus and its associated branches might contribute to inhibiting an increase in sac diameter. Based on these findings, it can be concluded that using non-dissipating embolic materials for nidus embolization might be an effective strategy to prevent sac enlargement.\u003c/p\u003e \u003cp\u003eThis study had some limitations. First, owing to its retrospective and limited-scale design. The relatively small size of the patient subgroups poses a challenge for robust statistical interpretation. Second, accurately determining T2EL associated branches may be challenging because of the inability to perform contrast-enhanced CT scans in certain patient categories, including those with renal dysfunction, contrast medium intolerance, or absence of sac enlargement. And, angiographic visualization via a 1.9 Fr catheter typically fails to adequately opacify the nidus and the entirety of inflow/outflow branches, potentially obscuring the true anatomical and pathophysiological details of the endoleak. Should two or more branch vessels remain patent, the specific embolic agent used within the nidus and/or branch vessels may be inconsequential, as persistent flow can facilitate aneurysmal growth and allow the embolic material to displace from its initial placement. Therefore, this study does not assert the efficacy of using NBCA alone to embolize all potentially nidus-related inflow/outflow branches. Consequently, this study may underrepresent the occlusive efficacy of NBCA when used as the sole embolic agent.Third, it is important to note that this study followed the Japanese guidelines, focusing on EVAR treatment for smaller AAAs. This could potentially introduce a bias into this results, as the European Society for Vascular Surgery guidelines recommend considering larger AAA sizes. So, given that aneurysmal sac diameter is known to influence natural growth rates, this discrepancy could potentially affect T2EL efficacy outcomes in larger AAAs. Therefore, future studies focusing on larger AAA are required to verify these preliminary findings.\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eThe results indicated that embolization of both the nidus and its associated branches using coils, incorporating NBCA glue as needed, was effective in preventing sac diameter increase in T2EL embolization. Embolization targeting the nidus with embolic agents that will not wash out may be an important therapeutic strategy for preventing aneurysmal expansion due to type 2 endoleak.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cem\u003eTAE\u003c/em\u003e transarterial embolization\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eT2EL\u003c/em\u003e type 2 endoleak\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eNBCA\u003c/em\u003e N-butyl-2-cyanoacrylate\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eEVAR\u003c/em\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eEndovascular abdominal aortic aneurysm repair\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Institutional Review Board approved this retrospective cohort study and waived the requirement for written informed consent.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eKO , JM , TO: Visualization, Formal analysis, Writing \u0026ndash; review \u0026amp; editing. NA, AY, TS, TO: Data curation. KK, SK: Writing \u0026ndash; review \u0026amp; editing. KO, TO: Conceptualization, Methodology, Validation, Supervision, Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eEndovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial. Lancet 365(9478):2187-2192. https://doi.org/10.1016/s0140-6736(05)66628-7.\u003c/li\u003e\n\u003cli\u003eAbularrage CJ, Patel VI, Conrad MF, Schneider EB, Cambria RP, Kwolek CJ (2012) Improved results using Onyx glue for the treatment of persistent type 2 endoleak after endovascular aneurysm repair. J Vasc Surg 56(3):630-636. https://doi.org/10.1016/j.jvs.2012.02.038.\u003c/li\u003e\n\u003cli\u003eChaikof EL, Dalman RL, Eskandari MK, Jackson BM, Lee WA, Mansour MA, Mastracci TM, Mell M, Murad MH, Nguyen LL, Oderich GS, Patel MS, Schermerhorn ML, Starnes BW (2018) The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm. J Vasc Surg 67(1):2-77.e72. https://doi.org/10.1016/j.jvs.2017.10.044.\u003c/li\u003e\n\u003cli\u003eCharitable JF, Patalano PI, Garg K, Maldonado TS, Jacobowitz GR, Rockman CB, Veith FJ, Cayne NS (2021) Outcomes of translumbar embolization of type II endoleaks following endovascular abdominal aortic aneurysm repair. J Vasc Surg 74(6):1867-1873. https://doi.org/10.1016/j.jvs.2021.06.030.\u003c/li\u003e\n\u003cli\u003eChen JX, Stavropoulos SW (2020) Type 2 Endoleak Management. 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Ann Vasc Surg 20(1):69-74. https://doi.org/10.1007/s10016-005-9382-z.\u003c/li\u003e\n\u003cli\u003eGonzalez-Urquijo M, Lozano-Balderas G, Fabiani MA (2020) Type II Endoleaks After EVAR: A Literature Review of Current Concepts. Vasc Endovascular Surg 54(8):718-724. https://doi.org/10.1177/1538574420945448.\u003c/li\u003e\n\u003cli\u003eGuo Q, Zhao J, Ma Y, Huang B, Yuan D, Yang Y, Du X (2020) A meta-analysis of translumbar embolization versus transarterial embolization for type II endoleak after endovascular repair of abdominal aortic aneurysm. J Vasc Surg 71(3):1029-1034.e1021. https://doi.org/10.1016/j.jvs.2019.05.074.\u003c/li\u003e\n\u003cli\u003eHorinouchi H, Okada T, Yamaguchi M, Maruyama K, Sasaki K, Gentsu T, Ueshima E, Sofue K, Kawasaki R, Nomura Y, Omura A, Okada K, Sugimoto K, Murakami T (2020) Mid-term Outcomes and Predictors of Transarterial Embolization for Type II Endoleak After Endovascular Abdominal Aortic Aneurysm Repair. 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J Vasc Surg 46(1):1-8. https://doi.org/10.1016/j.jvs.2007.02.073.\u003c/li\u003e\n\u003cli\u003eKarthikesalingam A, Thrumurthy SG, Jackson D, Choke E, Sayers RD, Loftus IM, Thompson MM, Holt PJ (2012) Current evidence is insufficient to define an optimal threshold for intervention in isolated type II endoleak after endovascular aneurysm repair. J Endovasc Ther 19(2):200-208. https://doi.org/10.1583/11-3762r.1.\u003c/li\u003e\n\u003cli\u003eKasirajan K, Matteson B, Marek JM, Langsfeld M (2003) Technique and results of transfemoral superselective coil embolization of type II lumbar endoleak. J Vasc Surg 38(1):61-66. https://doi.org/10.1016/s0741-5214(02)75467-0.\u003c/li\u003e\n\u003cli\u003eLederle FA, Freischlag JA, Kyriakides TC, Padberg FT, Jr., Matsumura JS, Kohler TR, Lin PH, Jean-Claude JM, Cikrit DF, Swanson KM, Peduzzi PN (2009) Outcomes following endovascular vs open repair of abdominal aortic aneurysm: a randomized trial. Jama 302(14):1535-1542. https://doi.org/10.1001/jama.2009.1426.\u003c/li\u003e\n\u003cli\u003eMewissen MW, Jan MF, Kuten D, Krajcer Z (2017) Laser-Assisted Transgraft Embolization: A Technique for the Treatment of Type II Endoleaks. J Vasc Interv Radiol 28(11):1600-1603. https://doi.org/10.1016/j.jvir.2017.07.029.\u003c/li\u003e\n\u003cli\u003eNana P, Spanos K, Heidemann F, Panuccio G, Kouvelos G, Rohlffs F, Giannoukas A, K\u0026ouml;lbel T (2022) Systematic review on transcaval embolization for type II endoleak after endovascular aortic aneurysm repair. J Vasc Surg 76(1):282-291.e282. https://doi.org/10.1016/j.jvs.2022.02.032.\u003c/li\u003e\n\u003cli\u003ePrinssen M, Verhoeven EL, Buth J, Cuypers PW, van Sambeek MR, Balm R, Buskens E, Grobbee DE, Blankensteijn JD (2004) A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms. N Engl J Med 351(16):1607-1618. https://doi.org/10.1056/NEJMoa042002.\u003c/li\u003e\n\u003cli\u003eSarac TP, Gibbons C, Vargas L, Liu J, Srivastava S, Bena J, Mastracci T, Kashyap VS, Clair D (2012) Long-term follow-up of type II endoleak embolization reveals the need for close surveillance. J Vasc Surg 55(1):33-40. https://doi.org/10.1016/j.jvs.2011.07.092.\u003c/li\u003e\n\u003cli\u003eSeike Y, Matsuda H, Shimizu H, Ishimaru S, Hoshina K, Michihata N, Yasunaga H, Komori K (2022) Nationwide Analysis of Persistent Type II Endoleak and Late Outcomes of Endovascular Abdominal Aortic Aneurysm Repair in Japan: A Propensity-Matched Analysis. Circulation 145(14):1056-1066. https://doi.org/10.1161/circulationaha.121.056581.\u003c/li\u003e\n\u003cli\u003eSpanos K, Nana P, Behrendt CA, Kouvelos G, Panuccio G, Heidemann F, Matsagkas M, Debus S, Giannoukas A, K\u0026ouml;lbel T (2020) Management of Abdominal Aortic Aneurysm Disease: Similarities and Differences Among Cardiovascular Guidelines and NICE Guidance. J Endovasc Ther 27(6):889-901. https://doi.org/10.1177/1526602820951265.\u003c/li\u003e\n\u003cli\u003eUltee KHJ, B\u0026uuml;ttner S, Huurman R, Bastos Gon\u0026ccedil;alves F, Hoeks SE, Bramer WM, Schermerhorn ML, Verhagen HJM (2018) Editor\u0026apos;s Choice - Systematic Review and Meta-Analysis of the Outcome of Treatment for Type II Endoleak Following Endovascular Aneurysm Repair. Eur J Vasc Endovasc Surg 56(6):794-807. https://doi.org/10.1016/j.ejvs.2018.06.009.\u003c/li\u003e\n\u003cli\u003eWalker J, Tucker LY, Goodney P, Candell L, Hua H, Okuhn S, Hill B, Chang RW (2015) Type II endoleak with or without intervention after endovascular aortic aneurysm repair does not change aneurysm-related outcomes despite sac growth. J Vasc Surg 62(3):551-561. https://doi.org/10.1016/j.jvs.2015.04.389.\u003c/li\u003e\n\u003cli\u003eYu H, Desai H, Isaacson AJ, Dixon RG, Farber MA, Burke CT (2017) Comparison of Type II Endoleak Embolizations: Embolization of Endoleak Nidus Only versus Embolization of Endoleak Nidus and Branch Vessels. J Vasc Interv Radiol 28(2):176-184. https://doi.org/10.1016/j.jvir.2016.10.002.\u003c/li\u003e\n\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":"Type 2 endoleak, Embolization, Coils, N-butyl-2-cyanoacrylate glue","lastPublishedDoi":"10.21203/rs.3.rs-4159651/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4159651/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eTransarterial embolization (TAE) of the nidus and branches prevents aneurysm sac growth due to Type 2 endoleaks (T2EL). Embolization materials include coils and liquid embolic substances such as N-butyl-2-cyanoacrylate (NBCA) glue, a type of liquid embolic glue. However, when the nidus is characterized by heterogeneous perigraft opacity on CT imaging with an ill-defined boundary within the sac, it becomes challenging to embolize the nidus directly, often resulting in the embolization of only the branches connected to it. Therefore, we aim to evaluate the efficacy of TAE for the endoleak nidus and side branches versus embolizing the side branches alone in preventing aneurysm sac enlargement after T2EL, comparing mid-term follow-up results.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e \u003cp\u003eIn a single-center retrospective cohort study, we reviewed consecutive 59 patients who underwent TAE for T2EL from September 2017 to August 2022. After excluding cases with less than 6 months follow-up or without abdominal aortic aneurysm, 40 patients were included in the analysis. Initial treatment for all patients included attempts at direct embolization of the endoleak nidus and side branches using coils and NBCA glue. Even if the nidus was reached, if embolization of the nidus proved difficult, the directly connected branches were embolized instead. Data were analyzed using the Kaplan\u0026ndash;Meier curve for estimating sac enlargement freedom, with the primary outcome being aneurysm sac diameter change post-T2EL embolization.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eNo visible endoleak nidus was detected in any patient after TAE. Of all patients (n\u0026thinsp;=\u0026thinsp;40), 60% (n\u0026thinsp;=\u0026thinsp;24) underwent embolization via direct cannulation to the nidus. Direct TAE involving the nidus and main branches with coils, supplemented with NBCA glue, considerably hindered sac enlargement (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Of 14 patients with sac enlargement, 72% (10 patients) had unsuccessful direct TAE, resulting in a significant association (p\u0026thinsp;=\u0026thinsp;0.006). On the other hand, 77% (20 of 26 patients) without sac enlargement experienced successful direct TAE. Three patients displayed sac enlargement even after successful direct TAE using only NBCA glue (p\u0026thinsp;=\u0026thinsp;0.04).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eDirect TAE of the endoleak nidus, using coils and supplemented with NBCA glue as necessary, is effective in preventing sac enlargement after T2EL embolization.\u003c/p\u003e","manuscriptTitle":"Transarterial Embolization of Type 2 Endoleak Using Coils and N-Butyl Cyanoacrylate: The Importance of Treating the Nidus and Sac Branches","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-10 17:24:26","doi":"10.21203/rs.3.rs-4159651/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":"0e1d6fe7-e27b-4e6e-9d34-88e8ba922d94","owner":[],"postedDate":"April 10th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-04-10T17:24:29+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-10 17:24:26","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4159651","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4159651","identity":"rs-4159651","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}