Focused abdominal ultrasound.

A focused point-of-care abdominal ultrasound is an examination performed at the patient's location and interpreted within the clinical context. This review gives an overview of this examination modality. The objective is to rapidly address predefined dichotomised questions about the presence of an abdominal aortic aneurysm, gallstones, cholecystitis, hydronephrosis, urinary retention, free intraperitoneal fluid, and small bowel obstruction. FAUS is a valuable tool for emergency physicians to promptly confirm various conditions upon the patients' arrival, thus reducing the time to diagnosis and in some cases eliminating the need for other imaging.

Latest evidence on chimney endovascular repair of abdominal aortic aneurysms and the renal artery angulation pitfall.

This article summarizes the key findings in literature up to date on the endovascular treatment of complex abdominal aortic aneurysms (AAAs) employing the chimney technique. Additionally, an unexplored pitfall is described regarding the target vessel angulation. Although balloon-expandable covered stents present more favorable configuration in downward-oriented target vessels, transverse and upward-oriented target vessels may benefit from other endovascular techniques imploring careful case planning and further investigation on the topic.

Physician-modified versus chimney endografting for pararenal aortic aneurysms: a systematic review and meta-analysis.

INTRODUCTION: We performed a systematic review and meta-analysis to assess the existing published evidence regarding the safety and efficacy of the endovascular aortic repair with chimney technique (ch-EVAR) and physician-modified stent-grafts (PMSGs) for the treatment of pararenal aortic aneurysm repair. EVIDENCE ACQUISITION: A systematic search of all relevant studies reported until October 2023 according to the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines was performed. The pooled 30-day mortality, peri- and postoperative complication rates were estimated using fixed or random effect methods. EVIDENCE SYNTHESIS: A total of 679 study titles were identified by the initial search strategy, of which 16 were considered eligible for inclusion in the meta-analysis. A total of 1094 patients (ch-EVAR N.=861 and PMSG N.=233) (90% male) were identified. The pooled 30-day mortality rate was 3.4% for ch-EVAR and 2.6% for PMSG. The major adverse events (MAE) in the early period was 14.7% for ch-EVAR and 18.5% PMSG, respectively. Higher occlusion rate was observed of the chimney stents grafts (8.2%) than the bridging stents (1.4%) during the follow-up period. CONCLUSIONS: Ch-EVAR and physician-modified technology are safe with low 30-day mortality in elective settings for pararenal aortic aneurysms repair. No significant differences were seen between the two surgical methods regarding the early major adverse events rate. However, higher occlusion rate for the chimneys can be expected over time.

Protagoras 3.0: feasibility of current fenestrated endografts and chimney technique for complex abdominal aortic aneurysms.

BACKGROUND: The aim of this study was to evaluate the anatomical feasibility of current available fenestrated endografts (FEVAR) and on-label chimney technique (EnChEVAR) in patients with complex abdominal aortic aneurysms (C-AAA). METHODS: Feasibility of EnChEVAR (Endurant II/IIS CE-marked [Medtronic]) and 4 types of FEVAR (Zenith Fenestrated CE-marked, Zenith Fenestrated Low-Profile [LP] custom-made device [CMD] [Cook Medical], Fenestrated Anaconda LoPro90 CMD, Fenestrated Treo CMD [Terumo Aortic]) was assessed according to the manufacturer's instructions for use. Computed tomography angiograms of patients with C-AAA previously included in the Protagoras 2.0 study were retrospectively reviewed. The aortic coverage was ideally planned to involve a maximum of two chimney grafts or fenestrations. RESULTS: Iliac access and aortic neck of 73 C-AAAs were analyzed. The overall feasibility was significantly different between EnChEVAR (33%) and FEVAR (Zenith Fenestrated 15%, Zenith Fenestrated LP 15%, Fenestrated Anaconda LoPro90 45%, Fenestrated Treo 48%). The iliac access feasibility was significantly lower for Zenith Fenestrated with standard profile compared to all other grafts. The aortic neck feasibility was significantly higher for EnChEVAR and both Terumo Aortic fenestrated stent grafts, compared to both Cook Medical grafts. The treatment using any of the three current available fenestrated grafts with lower profile (Zenith Fenestrated LP, Fenestrated Anaconda LoPro90, Fenestrated Treo) would have been feasible in 71% of the cases. CONCLUSIONS: Most of the patients treated by ChEVAR would have not been treated by first generation fenestrated stent graft. The current available fenestrated endografts, with lower profile and suitable also for angulated necks, increase the anatomical feasibility.

Early multicentric outcomes of the on-label and CE-marked combination of the Endurant with the Radiant chimney graft for the chimney endovascular aortic repair (EnChEVAR): The LaMuR Registry.

BACKGROUND: The aim of this study was to evaluate the early results of the CE-marked standardized device combination consisting of Endurant and the Radiant chimney graft (En-ChEVAR) for the treatment of juxtarenal aortic aneurysms. METHODS: We analyzed multicentric non-industry sponsored case series evaluating the EnChEVAR technique for patients treated between December 2022 and February 2024. Clinical, perioperative procedure-related and radiological data were collected. The primary outcome measure was the freedom of a type Ia gutter-related endoleak at postoperative computed tomography angiography (CTA). Secondary outcome measures included early type Ia endoleak-related reinterventions, target vessel complications including dissection or loss of target vessel, major adverse events, and mortality. Continuous variables were presented as median (interquartile range [IQR]) and categorical variables as count and percentage. RESULTS: Ten patients were included in the present study. Eight (80%) were males, in nine cases a single chimney was implanted, and the other one was a double chimney graft placement. The treated aneurysms had an infrarenal neck length of 3.4 (1.2) mm. The rate of main body oversizing was 30%. The new neck length after chimney graft placement was 18 (3) mm. The median procedural time was 130 (17) mm, contrast medium use was 109 (26) mL, radiation time was 45 (12) min. The technical success was 100%. No type Ia endoleak was detected at the postoperative CTA. There were no target vessel issues. No major adverse events or death were observed. CONCLUSIONS: First reported cohort of patients treated with EnChEVAR demonstrated reproducible clinical and procedural outcomes within the 3 vascular centers with total exclusion of the aneurysms, patent renal arteries, and no evidence of gutter-related type IA endoleak. Further evidence with larger sample size of treated patients and longer follow-up are needed.

Computed tomography-based automated measurement of abdominal aortic aneurysm using semantic segmentation with active learning.

Accurate measurement of abdominal aortic aneurysm is essential for selecting suitable stent-grafts to avoid complications of endovascular aneurysm repair. However, the conventional image-based measurements are inaccurate and time-consuming. We introduce the automated workflow including semantic segmentation with active learning (AL) and measurement using an application programming interface of computer-aided design. 300 patients underwent CT scans, and semantic segmentation for aorta, thrombus, calcification, and vessels was performed in 60-300 cases with AL across five stages using UNETR, SwinUNETR, and nnU-Net consisted of 2D, 3D U-Net, 2D-3D U-Net ensemble, and cascaded 3D U-Net. 7 clinical landmarks were automatically measured for 96 patients. In AL stage 5, 3D U-Net achieved the highest dice similarity coefficient (DSC) with statistically significant differences (p < 0.01) except from the 2D-3D U-Net ensemble and cascade 3D U-Net. SwinUNETR excelled in 95% Hausdorff distance (HD95) with significant differences (p < 0.01) except from UNETR and 3D U-Net. DSC of aorta and calcification were saturated at stage 1 and 4, whereas thrombus and vessels were continuously improved at stage 5. The segmentation time between the manual and AL-corrected segmentation using the best model (3D U-Net) was reduced to 9.51 ± 1.02, 2.09 ± 1.06, 1.07 ± 1.10, and 1.07 ± 0.97 min for the aorta, thrombus, calcification, and vessels, respectively (p < 0.001). All measurement and tortuosity ratio measured - 1.71 ± 6.53 mm and - 0.15 ± 0.25. We developed an automated workflow with semantic segmentation and measurement, demonstrating its efficiency compared to conventional methods.

Comparison between the outcomes of transfemoral access and transfemoral access with adjunct upper extremity access in patients undergoing endovascular aortic repair: A pilot systematic review and meta-analysis.

Endovascular aortic repair is an emerging novel intervention for the management of abdominal aortic aneurysms. It is crucial to compare the effectiveness of different access sites, such as transfemoral access (TFA) and upper extremity access (UEA). An electronic literature search was conducted using PubMed, EMBASE, and Google Scholar databases. The primary endpoint was the incidence of stroke/transient ischemic attack (TIA), while the secondary endpoints included technical success, access-site complications, mortality, myocardial infarction (MI), spinal cord ischemia, among others. Forest plots were constructed for the pooled analysis of data using the random-effects model in Review Manager, version 5.4. Statistical significance was set at p < 0.05. Our findings in 9403 study participants (6228 in the TFA group and 3175 in the UEA group) indicate that TFA is associated with a lower risk of stroke/TIA [RR: 0.55; 95% CI: 0.40-0.75; p = 0.0002], MI [RR: 0.51; 95% CI: 0.38-0.69; p < 0.0001], spinal cord ischemia [RR: 0.41; 95% CI: 0.32-0.53, p < 0.00001], and shortens fluoroscopy time [SMD: -0.62; 95% CI: -1.00 to -0.24; p = 0.001]. Moreover, TFA required less contrast agent [SMD: -0.33; 95% CI: -0.61 to -0.06; p = 0.02], contributing to its appeal. However, no significant differences emerged in technical success [p = 0.23], 30-day mortality [p = 0.48], ICU stay duration [p = 0.09], or overall hospital stay length [p = 0.22]. Patients with TFA had a lower risk of stroke, MI, and spinal cord ischemia, shorter fluoroscopy time, and lower use of contrast agents. Future large-scale randomized controlled trials are warranted to confirm and strengthen these findings.

Image-based assessment of aortoiliac aneurysm anatomical characteristics in patients from the global iliac branch study.

OBJECTIVE: Endovascular repair is the preferred treatment for aortoiliac aneurysm, with preservation of at least one internal iliac artery recommended. This study aimed to assess pre-endovascular repair anatomical characteristics of aortoiliac aneurysm in patients from the Global Iliac Branch Study (GIBS, NCT05607277) to enhance selection criteria for iliac branch devices (IBD) and improve long-term outcomes. METHODS: Pre-treatment CT scans of 297 GIBS patients undergoing endovascular aneurysm repair were analyzed. Measurements included total iliac artery length, common iliac artery length, tortuosity index, common iliac artery splay angle, internal iliac artery stenosis, calcification score, and diameters in the device's landing zone. Statistical tests assessed differences in anatomical measurements and IBD-mediated internal iliac artery preservation. RESULTS: Left total iliac artery length was shorter than right (6.7 mm, P = .0019); right common iliac artery less tortuous (P = .0145). Males exhibited greater tortuosity in the left total iliac artery (P = .0475) and larger diameter in left internal iliac artery's landing zone (P = .0453). Preservation was more common on right (158 unilateral, 34 bilateral) than left (105 unilateral, 34 bilateral). There were 192 right-sided and 139 left-sided IBDs, with 318 IBDs in males and 13 in females. CONCLUSION: This study provides comprehensive pre-treatment iliac anatomy analysis in patients undergoing endovascular repair with IBDs, highlighting differences between sides and sexes. These findings could refine patient selection for IBD placement, potentially enhancing outcomes in aortoiliac aneurysm treatment. However, the limited number of females in the study underscores the need for further research to generalize findings across genders.

Endovascular repair of an abdominal aortic aneurysm with external iliac artery occlusion using VBX as the contralateral leg via axillary delivery: A case report.

RATIONALE: A hostile iliac access route is an important consideration when enforcing endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAA). Herein, we report a case of AAA with unilateral external iliac artery occlusion, for which bifurcated EVAR was successfully performed using a single femoral and brachial artery access. PATIENT CONCERNS: A 76-year-old man who had undergone surgery for lung cancer 4.5 years prior was diagnosed AAA by computed tomography (CT). DIAGNOSIS: Two and a half years before presentation, CT revealed an infrarenal 48 mm AAA, which had enlarged to 57 mm by 2 months preoperatively. CT identified occlusion from the right external iliac artery to the right common femoral artery, with no observed ischemic symptoms in his right leg. The right external iliac artery, occluded and atrophied, had a 1 to 2 mm diameter. INTERVENTION: Surgery was commenced with the selection of a Zenith endovascular graft (Cook Medical) with an extended body length. Two Gore Viabahn VBX balloon expandable endoprosthesis (VBX; W.L. Gore & Associate) were delivered from the right axilla as the contralateral leg. OUTCOMES: CT scan on the 2nd day after surgery revealed no endoleaks. LESSONS: While the long-term results remain uncertain, this method may serve as an option for EVAR in patients with unilateral external iliac artery occlusion.

Visualizing the crucial roles of plasma membrane and peroxynitrite during abdominal aortic aneurysm using two-photon fluorescence imaging.

Peroxynitrite (ONOO-) and cell plasma membrane (CPM) are two key factors in cell pyroptosis during the progression of abdominal aortic aneurysm (AAA). However, their combined temporal and spatial roles in initiating AAA pathogenesis remain unclear. Herein, we developed a two-photon fluorescence probe, BH-Vis, enabling real-time dynamic detection of CPM and ONOO- changes, and revealing their interplay in AAA. BH-Vis precisely targets CPM with reduced red fluorescence intensity correlating with diminished CPM tension. Concurrently, a blue shift of the fluorescence signal of BH-Vis occurs in response to ONOO- offering a reliable ratiometric detection mode with enhanced accuracy by minimizing external testing variables. More importantly, two photon confocal imaging with palmitic acid (PA) and ganglioside (GM1) manipulation, which modulating cell pyroptosis, showcases reliable fluorescence fluctuations. This groundbreaking application of BH-Vis in a mouse AAA model demonstrates its significant potential for accurately identifying cell pyroptosis levels during AAA development.

Impact of iliac access in elective and non-elective endovascular repair of abdominal aortic aneurysm.

Endovascular aortic repair (EVAR) is nowadays the establishment treatment for patients with abdominal aortic aneurysm (AAA) both in elective and urgent setting. Despite the large applicability and satisfactory results, the presence of hostile iliac anatomy affects both technical and clinical success. This narrative review aimed to report the impact of iliac access and related adjunctive procedures in patients undergoing EVAR in elective and non-elective setting. Hostile iliac access can be defined in presence of narrowed, tortuous, calcified, or occluded iliac arteries. These iliac characteristics can be graded by the anatomic severity grade score to quantitatively assess anatomic complexity before undergoing treatment. Literature shows that iliac hostility has an impact on device navigability, insertion and perioperative and postoperative results. Overall, it has been correlated to higher rate of access issues, representing up to 30% of the first published EVAR experience. Recent innovations with low-profile endografts have reduced large-bore sheaths related issues. However, iliac-related complications still represent an issue, and several adjunctive endovascular and surgical strategies are nowadays available to overcome these complications during EVAR. In urgent settings iliac hostility can significantly impact on particular time sensitive procedures. Moreover, in case of severe hostility patients might be written off for EVAR repair might be inapplicable, exposing to higher mortality/morbidity risk in this urgent/emergent setting. In conclusion, an accurate anatomical evaluation of iliac arteries during preoperative planning, materials availability, and skilled preparation to face iliac-related issues are crucial to address these challenges.

Importance of sac regression after EVAR and the role of EndoAnchors.

The initial success and widespread adoption of endovascular aneurysm repair (EVAR) for the treatment of abdominal aortic aneurysms have been tempered by numerous reports of secondary interventions and increased long-term mortality compared with open repair. Over the past decade, several studies on postoperative sac dynamics after EVAR have suggested that the presence of sac regression is a benign feature with a favorable prognosis. Conversely, increasing sacs and even stable sacs can be indicators of more unstable sac behavior with worse outcomes in the long-term. Endoleaks were initially perceived as the main drivers of sac behavior. However, the observation that sac regression can occur in the presence of endoleaks, and vice versa - increasing sacs without evidence of endoleak - on imaging studies, suggests the involvement of other contributing factors. These factors can be divided into anatomical factors, patient characteristics, sac thrombus composition, and device-related factors. The shift of interest away from especially type 2 endoleaks is further supported by promising results with the use of EndoAnchors regarding postoperative sac behavior. This review provides an overview of the existing literature on the implications and known risk factors of post-EVAR sac behavior, describes the accurate measurement of sac behavior, and discusses the use of EndoAnchors to promote sac regression.

The ARIA trial protocol: a randomised controlled trial to assess the clinical, technical, and cost-effectiveness of a cloud-based, ARtificially Intelligent image fusion system in comparison to standard treatment to guide endovascular Aortic aneurysm repair.

BACKGROUND: Endovascular repair of aortic aneurysmal disease is established due to perceived advantages in patient survival, reduced postoperative complications, and shorter hospital lengths of stay. High spatial and contrast resolution 3D CT angiography images are used to plan the procedures and inform device selection and manufacture, but in standard care, the surgery is performed using image-guidance from 2D X-ray fluoroscopy with injection of nephrotoxic contrast material to visualise the blood vessels. This study aims to assess the benefit to patients, practitioners, and the health service of a novel image fusion medical device (Cydar EV), which allows this high-resolution 3D information to be available to operators at the time of surgery. METHODS: The trial is a multi-centre, open label, two-armed randomised controlled clinical trial of 340 patient, randomised 1:1 to either standard treatment in endovascular aneurysm repair or treatment using Cydar EV, a CE-marked medical device comprising of cloud computing, augmented intelligence, and computer vision. The primary outcome is procedural time, with secondary outcomes of procedural efficiency, technical effectiveness, patient outcomes, and cost-effectiveness. Patients with a clinical diagnosis of AAA or TAAA suitable for endovascular repair and able to provide written informed consent will be invited to participate. DISCUSSION: This trial is the first randomised controlled trial evaluating advanced image fusion technology in endovascular aortic surgery and is well placed to evaluate the effect of this technology on patient outcomes and cost to the NHS. TRIAL REGISTRATION: ISRCTN13832085. Dec. 3, 2021.

Increasing abdominal aortic aneurysm curvature visibility using 3D dual probe bistatic ultrasound imaging combined with probe translation.

High frame rate ultrasound (US) imaging techniques in 3D are promising tools for capturing abdominal aortic aneurysms (AAAs) over time, however, with the limited number of channel-to-element connections current footprints are small, which limits the field of view. Moreover, the maximal steering angle of the ultrasound beams in transmit and the maximal receptance angle in receive are insufficient for capturing the curvy shape of the AAA. Therefore, an approach is needed towards large arrays. In this study, high frame rate bistatic 3D US data (17 Hz) were acquired with two synchronized matrix arrays positioned at different locations (multi-aperture imaging) using a translation stage to simulate what a larger array with limited channel-to-element connections can potentially achieve. Acquisitions were performed along an AAA shaped phantom with different probe tilting angles (0 up to ± 30°). The performance of different multi-aperture configurations was quantified using the generalized contrast-to-noise ratio of the wall and lumen (gCNR). Furthermore, a parametric model of the multi-aperture system was used to estimate in which AAA wall regions the contrast is expected to be high. This was evaluated for AAAs with increasing diameters and curvature. With an eight-aperture 0° probe angle configuration a 69 % increase in field of view was measured in the longitudinal direction compared to the field of view of a single aperture configuration. When increasing the number of apertures from two to eight, the gCNR improved for the upper wall and lower wall by 35 % and 13 % (monostatic) and by 36 % and 13 % (bistatic). Contrast improvements up to 22 % (upper wall) and 12 % (lower wall) are achieved with tilted probe configurations compared to non-tilted configurations. Moreover, with bistatic imaging with tilted probe configurations gCNR improvements up to 4 % (upper wall) and 7 % (lower wall) are achieved compared to monostatic imaging. Furthermore, imaging with a larger inter-probe distance improved the gCNR for a ± 15° probe angle configuration. The gCNR has an expected pattern over time, where the contrast is lower when there is more wall motion (systole) and higher when motion is reduced (diastole). Furthermore, a higher frame rate (45 Hz) yields a lower gCNR, because fewer compound angles are used. The results of the parametric model suggest that a flat array is suitable for imaging AAA shapes with limited curvature, but that it is not suitable for imaging larger AAA shapes with more curvature. According to the model, tilted multi-aperture configurations combined with bistatic imaging can achieve a larger region with high contrast compared to non-tilted configurations. The findings of the model are in agreement with experimental findings. To conclude, this study demonstrates the vast improvements in field of view and AAA wall visibility that a large, sparsely populated 3D array can potentially achieve when imaging AAAs compared to single or dual aperture imaging. In the future, larger arrays, less thermal noise, more steering, and more channel-to-element connections combined with carefully chosen orientations of (sub-) apertures will likely advance 3D imaging of AAAs.

Trends in AAA Repair in Australia Over Twenty Years.

Background: The advent of endovascular techniques has revolutionised the treatment of abdominal aortic aneurysms (AAA). Many countries have seen a transition from open AAA repair (OAR) to endovascular AAA repair (EVAR) over the past 25 years. The only study done in Australia that describes this change was done in the private sector. Majority of healthcare in Australia is delivered through the public, universal healthcare system. The aim of this study was to evaluate the trends in AAA repair in the Australian public sector over the past two decades. Methods: The Australian Institute of Health and Welfare (AIHW) Procedures Data Cubes from the National Hospitals Data Collection was used to extract data pertaining to AAA repairs from 2000 to 2021. Population data from the Australian Bureau of Statistics was used to calculate incidence of each type of repair per 100,000 population. Results: There were 65,529 AAA repairs performed in the Australian public sector from 2000 to 2021. EVARs accounted for 64.4% (42,205) and OARs accounted for 35.6% (23, 324) of them. EVAR surpassed OAR as the preferred method of AAA repair in 2006. This trend was observed in both males and females and across all age groups. Conclusion: There was a consistent and steady transition from OAR to EVAR over the 21 year period with EVAR surpassing OAR as the preferred method of AAA repair relatively early in Australia compared to other countries. Further research that investigates medium- and long-term outcomes of newer stent grafts is needed to further ascertain the continued viability and effectiveness of this trend in AAA treatment.

A retrospective cohort study of incidental abdominal aortic aneurysms on routine abdominal computed tomography scans in Te Tairawhiti (2018-2019).

AIM: Ruptured abdominal aortic aneurysm (rAAA) is associated with a high mortality rate which, is especially significant in rural and provincial regions. In Aotearoa New Zealand, Maori experience higher rates of AAA and worse overall medium-term survival following AAA repair. This study aimed to understand the prevalence of incidental AAA on routine abdominal computed tomography (CT) scans over 12 months. METHOD: A retrospective review of all abdominal CT scans performed on patients ≥50 years at Gisborne Hospital between 1 December 2018-1 December 2019 was performed. RESULTS: A total of 811 scans were reviewed, with 42 incidental AAA detected (5.2%). The majority of incidental AAA were in males aged ≥65 (65.8%), with a higher prevalence for Maori compared to New Zealand European (NZE) (16.2% vs 8.1%, p=0.052). This pattern was also seen in females, aged ≥65 (10.9% in Maori vs 3.8% in NZE, p=0.047). CONCLUSION: The detection of AAA on routine abdominal CT scans appears to be a useful adjunct in lieu of targeted AAA screening in our region. A high prevalence of incidental AAA (5.2%) over 12 months, with a significantly higher prevalence noted in Maori males and females ≥65 years (16.2% and 10.9%), was observed.

Efficacy of Sac Coil Embolization in Endovascular Aortic Repair for Sac Shrinkage in Patients at a High Risk of Type II Endoleak from Lumbar Arteries.

BACKGROUND: In endovascular aortic repair (EVAR), preemptive embolization of sac branch vessels is effective in preventing postoperative type II endoleak (T2EL). However, this technique has not been widely adopted especially for lumbar arteries (LAs) because of technical difficulties and time constraints. This study aimed to investigate the efficacy of nonselective sac coil embolization, which is a simpler surgical method, in postoperative sac shrinkage for patients at a high risk of T2EL from LAs. METHODS: We retrospectively assessed 76 patients who underwent elective EVAR for abdominal aortic aneurysm with 4 or more patent LAs or at least 1 patent LA of ≥2 mm at our hospital between January 2014 and December 2022. The patients who underwent sac coil embolization were included in Group Ⅰ (n = 20), and the others were divided into 2 groups: those with an inferior mesenteric artery that was originally occluded or embolized by coils or stent graft bodies (Group Ⅱ, n = 21), and those without that (Group Ⅲ, n = 35). In Group Ⅰ, 0.035-inch coils were inserted into the sac after complete stent graft deployment. The cumulative incidence of sac shrinkage (≥5 mm) was compared between the groups. Further, univariable and multivariable Cox regression analyses were used to determine the predictors of sac shrinkage. RESULTS: Sac shrinkage (≥5 mm) was observed more frequently in Group Ⅰ (50%) than in Group Ⅱ (19%) and Group Ⅲ (17%) (P = 0.052 and 0.043, respectively). The cumulative incidence of sac shrinkage was significantly higher in Group Ⅰ than in Group Ⅱ (log-rank P = 0.039) and Group Ⅲ (log-rank P = 0.024). Multivariable Cox regression analyses revealed that sac embolization was a significant predictor of sac shrinkage (hazard ratio, 4.23; 95% confidence interval, 1.66-10.8; P = 0.003). CONCLUSIONS: Nonselective sac coil embolization in EVAR is potentially effective for sac shrinkage in the early postoperative phase in patients at high risk of T2EL from LAs. This simple procedure may improve prognosis after EVAR.