One-year sac regression is associated with freedom from fatal adverse events after endovascular aneurysm repair

Cause of death among patients following repair of juxtarenal aneurysm with physician-modified endografts

OBJECTIVE

The use of physician-modified endografts (PMEGs) to treat juxtarenal aortic aneurysms has increased significantly over the past 10 years. However, there exists a paucity of data beyond 5 years. This study compares long-term outcomes and cause of death between patients who did and did not survive beyond 5 years after PMEG for juxtarenal aneurysm.

METHODS

All patients with >5 years of follow-up data enrolled in a prospective, physician-sponsored investigational device exemption clinical trial treated with PMEG for juxtarenal aneurysm were included. Univariate analysis was used to compare demographics, anatomical and operative characteristics, late outcomes, and cause of death between patients who survived beyond 5 years and those who did not. Death on hospice, clinical follow-up status, and whether patients declined a secondary intervention were also evaluated. Survival was assessed with Kaplan-Meier analysis. Predictors of overall mortality and mortality before 5 years were determined using Cox regression analysis.

RESULTS

We included 98 patients with juxtarenal aneurysm wgo underwent PMEG from 2011 to 2018; 64 (65.3%) survived beyond 5 years and 34 (34.7%) did not. Patients who survived beyond 5 years were younger (73 years vs 78 years; P = .04) with a greater prevalence of preoperative antiplatelet use (81.3% vs 61.8%; P = .047). There were no differences in comorbidities, symptomatic presentation, or anatomical or operative characteristics. Patients who survived beyond 5 years were less likely to experience a perioperative adverse event (10.9% vs 38.2%; P < .01) and pulmonary complication (1.6% vs 17.7%; P = .01). There were no differences in late outcomes, including reintervention, aortic sac behavior, endoleak, or visceral patency. Patients who survived beyond 5 years more frequently died on hospice (58.6% vs 17.6%; P < .01), were lost to aortic-specific clinical follow-up (48.4% vs 5.9%; P < .01), and declined a secondary intervention (9.4% vs 2.9%; P = .04). For the entire study cohort, aortic-related mortality was 9.5%. Survival was 87% at 1 year, 65% at 5 years, and 10% at 10 years. Cardiac comorbidities (15.9%), systemic decline (15.9%), stroke (14.2%), and cancer (12.9%) accounted for the leading causes of death, with no differences between the two cohorts. On adjusted analysis, sac regression was associated with reduced mortality for the entire patient cohort (hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.18-0.76) and those who died before 5 years (HR, 0.37; 95% CI, 0.16-0.92). Meanwhile, congestive heart failure (HR, 6.02; 95% CI, 1.60-22.65) was associated with increased mortality for patients who did not survive beyond 5 years.

CONCLUSIONS

Patients who undergo PMEG for juxtarenal aneurysm are more likely to die from underlying medical comorbidities; aortic-related mortality accounts for <10% of total deaths. Patients who do not survive beyond 5 years are older and experience more perioperative complications, whereas patients who survive beyond 5 years are more likely to die on hospice, be lost to clinical follow-up, and decline a secondary intervention. These findings reflect the high degree of chronic disease burden for this patient population, even after successful treatment of their aortic pathology.

Association between abdominal aortic aneurysm sac shrinkage and aneurysm wall enhancement after endovascular aneurysm repair

OBJECTIVE

Aneurysm sac shrinkage after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms has clinical significance. In this study, we analyzed sac shrinkage after EVAR, focusing on aneurysm wall enhancement (AWE).

METHODS

This single-center retrospective cohort study included 355 patients who underwent elective bifurcated EVAR for infrarenal abdominal aortic aneurysms between June 2007 and December 2020. AWE was assessed using computed tomography angiography performed 3 to 12 months after surgery. The primary outcome was sac shrinkage, which was defined as a ≥5 mm decrease in sac diameter after 3 years. A persistent type II endoleak (pT2EL) was defined as any type II endoleak lasting ≥6 months postoperatively. The associations between AWE and sac shrinkage were analyzed via Kaplan-Meier analysis and subgroup analysis of patients with pT2ELs.

RESULTS

Of the 355 patients, 187 (52.7%) exhibited signs of sac shrinkage. AWE was significantly more common in the sac shrinkage group than in the nonshrinkage group (72.2% vs 51.8%; P < .0001). Multivariate analysis identified AWE as a factor significantly contributing to sac shrinkage 3 years after EVAR (P = .0002; odds ratio [OR], 4.10; 95% confidence interval [CI], 1.87-8.98). Having fewer than five patent lumbar arteries preoperatively was also associated with sac shrinkage (P = .0020; OR, 2.10; 95% CI, 1.31-3.36). According to the Kaplan-Meier curves, the AWE group exhibited significant sac shrinkage (log-rank test; P < .0001). In a subgroup analysis of patients who developed pT2EL, AWE was the only factor significantly contributing to sac shrinkage 3 years after EVAR (P = .0002; OR, 4.10; 95% CI, 1.87-8.98).

CONCLUSIONS

This study revealed a significant association between AWE and sac shrinkage after EVAR. Further research, including histopathological studies, is needed to elucidate the mechanism of the association between sac dynamics and AWE.

The Association Between the D-dimer Level at 1 Year After EVAR and Sac Diameter Change in Patients With Persistent Type 2 Endoleak

PURPOSE

Recent studies suggested that continuous clotting renewal in thrombi plays a central role in sac enlargement after endovascular aneurysm repair (EVAR). We reviewed patients with persistent type 2 endoleak (T2EL) to estimate the impact of D-dimer level on sac enlargement.

METHODS

A retrospective review of elective EVAR for infrarenal abdominal aortic aneurysm performed between June 2007 and February 2020. Persistent T2EL was defined as T2EL confirmed at both the 6 and 12 month contrast-enhanced computed tomography (CECT) follow-ups. "Isolated" T2EL was defined as T2EL without other types of endoleak within 12 months. Patients with >2 year follow-up, persistent isolated T2ELs, and D-dimer level data at 1 year (DD1Y) were included. Patients with any reintervention within 12 months were excluded. The association between DD1Y and aneurysm enlargement (AnE), defined as a ≥5 mm diameter increase, within 5 years was analyzed. Among 761 conventional EVAR, 515 patients had >2 years of follow-up. Thirty-three patients with any reintervention within 12 months and 127 patients without CECT at either 6 or 12 months were excluded. Among 131 patients with persistent isolated T2ELs, 74 patients with DD1Y data were enrolled. During a 37 month median follow-up [25-60, IQR], 24 AnEs were observed. In the AnE patients, the median DD1Y was significantly higher than that in the other patients (12.30 [6.88-21.90] vs 7.62 [4.41-13.00], P=0.024). ROC curve analysis indicated that the optimal cutoff point of DD1Y for AnE was 5.5 µg/mL (AUC=0.681). In univariate analysis, angulated neck, occlusion of the inferior mesenteric artery, and DD1Y≥5.5 µg/mL were significantly associated with AnE (P= 0.037, 0.038, and 0.010). Cox regression analysis revealed that DD1Y≥5.5 µg/mL was correlated with AnE (P=0.042, HR [95% CI] 4.520 [1.056-19.349]).

CONCLUSION

A 1 year higher D-dimer level can potentially predict AnE within 5 years in persistent T2EL patients. AnE was considered improbable when the D-dimer level was low enough.Clinical ImpactThe present study suggests that a 1-year higher D-dimer level could potentially predict aneurysm expansion within 5 years in patients with persistent type 2 endoleak (T2EL). On the other hand, aneurysm expansion was considered unlikely if the D-dimer level was low enough.As there are many patients with T2EL who require regular follow-up, any predictor of future aneurysm expansion could be of great help in conserving medical resources. In patients with a low likelihood of future expansion, we might consider delaying follow-up, similar to patients with sac shrinkage.

Impact of Significant Sac Shrinkage on Endograft Tortuosity at 5 Years Postendovascular Aortic Aneurysm Repair: A Retrospective Analysis

BACKGROUND

Significant sac shrinkage after endovascular aortic aneurysm repair (EVAR) is generally considered a positive outcome indicative of durable clinical success. However, its impact on endograft configuration is rarely addressed. Sac remodeling and volume loss due to shrinkage can potentially cause deformation of endograft components, resulting in limb angulation and compression. We investigated the hypothesis that significant sac shrinkage could affect endograft tortuosity at 5 years post-EVAR.

METHODS

We retrospectively reviewed patients who underwent elective EVAR for infrarenal abdominal aortic aneurysm between June 2007 and December 2018. Patients with early postoperative and 5-year follow-up computed tomography images were included. Patients treated with modular bifurcated endografts (Zenith, Endurant, Excluder, and Incraft) were analyzed. The "shrinkage" group comprised patients with >10 mm diameter reduction, while the "stable" group had ± 5 mm diameter change at 5 years. Tortuosity index (TI) was calculated as the ratio of centerline distance to straight-line distance between proximal and distal endograft edges. The association between sac shrinkage and ≥5% increase of TI (≥5%ΔTI) was analyzed for both ipsilateral and contralateral sides.

RESULTS

Of 136 patients enrolled, 80 were in the shrinkage group and 56 in the stable group. On the ipsilateral side, ≥5%ΔTI was observed in 24 cases (17.6%). The patients with ipsilateral ≥5%ΔTI had significantly shorter median neck lengths (22 mm vs. 30 mm, P = 0.030). Sac shrinkage ≥15 mm was negatively associated with ≥5%ΔTI compared to stable sac (P = 0.027). Logistic regression showing sac shrinkage ≥15 mm had a significant negative correlation with ≥5%ΔTI (P = 0.025, hazard ratio [95% confidence interval]: 0.218 [0.057-0.824]). On the contralateral side, ≥5%ΔTI (19 cases, 14.0%) was associated with shorter neck length but not with sac shrinkage. In the shrinkage group, cross-leg positioning resulted in a significant increase in ipsilateral TI at 5 years compared to straight positioning (median ΔTI: 1.8% vs. 0.0%, P = 0.013). No reinterventions for leg-related events were necessary during the 5-year follow-up period.

CONCLUSIONS

Contrary to our initial hypothesis, significant sac shrinkage does not adversely affect endograft configuration and may help stabilize tortuosity on the ipsilateral side. However, in patients with crossed-leg configuration, continued vigilant observation may be warranted even after achieving sac shrinkage, as it could exacerbate tortuosity. Shorter neck length was associated with increased tortuosity on both sides. Further research is needed to confirm these findings and consider potential confounding factors, including the impact of different endograft designs.

Potential of D-Dimer as a Tool to Rule Out Sac Expansion in Patients With Persistent Type 2 Endoleaks After Endovascular Aneurysm Repair

PURPOSE

In managing type 2 endoleak (T2EL) following endovascular aortic aneurysm repair (EVAR), an indication for reintervention is aneurysm enlargement (AnE). A previous study found that low D-dimer levels (DDLs) at 1 year were associated with reduced AnE risk in patients with persistent T2ELs (pT2ELs). This study analyzed patients with pT2ELs to determine the correlation between DDLs at annual follow-ups and AnE and proposed a follow-up protocol incorporating DDL monitoring.

METHODS

A retrospective review of elective EVAR cases between June 2007 and January 2021 identified "persistent" T2EL as confirmed at both 6- and 12-month contrast-enhanced CT studies. "Isolated" T2EL referred to cases without other endoleak types within 12 months. Inclusion criteria comprised >2 years of follow-up, isolated pT2ELs at 1 year, and DDL data at any annual follow-up over 5 years. The association between DDL and AnE, defined as ≥5 mm expansion within 5 years, was analyzed.

RESULTS

A total of 109 patients with DDL data at 288 time points were enrolled. During a median follow-up of 49 months [31-60, IQR], 43 AnE were observed. In patients without AnE and with DDL data at 1 and 2 years (N=77 and 56), lower DDLs were associated with a reduced AnE risk (p=0.03 and 0.01). Optimal cutoff points were 5.4 and 5.3 µg/mL (AUC=0.651 and 0.702) with high negative predictive values (86.9% and 93.8%). Cox regression analyses confirmed that DDLs surpassing the cutoff values correlated significantly with AnE (p=0.042 and p=0.038). Our simulated protocol for omitting imaging studies in patients with stable aneurysms and low DDL might have overlooked one AnE but could have saved 28 imaging studies over 3 years if implemented on our patients.

CONCLUSION

Low DDLs at the 1- and 2-year follow-ups can potentially exclude AnE in pT2EL patients, suggesting DDL monitoring as a resource-saving approach.

CLINICAL IMPACT

The management of type 2 endoleaks in post-EVAR patients has been a topic of debate. This retrospective single-center study, featuring strict inclusion criteria, included 109 patients with persistent type 2 endoleaks. The findings indicate that patients with lower D-dimer levels at 1- and 2-year follow-ups are unlikely to experience sac enlargement ≥5 mm within 5 years, even in the presence of type 2 endoleaks. This study suggests that D-dimer monitoring has the potential to reduce reliance on imaging studies for the follow-up of patients with type 2 endoleaks, leading to significant savings in medical resources.

The sac evolution imaging follow-up after endovascular aortic repair: An international expert opinion-based Delphi consensus study

OBJECTIVE

Management of follow-up protocols after endovascular aortic repair (EVAR) varies significantly between centers and is not standardized according to sac regression. By designing an international expert-based Delphi consensus, the study aimed to create recommendations on follow-up after EVAR according to sac evolution.

METHODS

Eight facilitators created appropriate statements regarding the study topic that were voted, using a 4-point Likert scale, by a selected panel of international experts using a three-round modified Delphi consensus process. Based on the experts' responses, only those statements reaching a grade A (full agreement ≥75%) or B (overall agreement ≥80% and full disagreement <5%) were included in the final document.

RESULTS

One-hundred and seventy-four participants were included in the final analysis, and each voted the initial 29 statements related to the definition of sac regression (Q1-Q9), EVAR follow-up (Q10-Q14), and the assessment and role of sac regression during follow-up (Q15-Q29). At the end of the process, 2 statements (6.9%) were rejected, 9 statements (31%) received a grade B consensus strength, and 18 (62.1%) reached a grade A consensus strength. Of 27 final statements, 15 (55.6%) were classified as grade I, whereas 12 (44.4%) were classified as grade II. Experts agreed that sac regression should be considered an important indicator of EVAR success and always be assessed during follow-up after EVAR.

CONCLUSIONS

Based on the elevated strength and high consistency of this international expert-based Delphi consensus, most of the statements might guide the current clinical management of follow-up after EVAR according to the sac regression. Future studies are needed to clarify debated issues.

The real-world incidence and predictors of sac regression in patients with infrarenal abdominal aortic aneurysm after standard EVAR

OBJECTIVE

Sac regression (SR) is a surrogate marker of satisfied endovascular aneurysm repair (EVAR). This research aims to investigate the incidence and predictors of SR in a Chinese population.

DESIGN

Single centre retrospective cohort study.

METHODS

Consecutive patients with infrarenal abdominal aortic aneurysms (AAAs) who underwent standard EVAR were retrospectively reviewed. SR was defined as sac shrinkage > 5 mm on computed tomography images, while major SR (MaSR) was ≥ 10 mm sac shrinkage. The cumulative rate was calculated by Kaplan-Meier analysis and predictors were identified by the Cox regression model.

RESULTS

A total of 469 patients (median age, 71 years old) were included. The majority of them (86.6 %) were male. With a median time of 13.6 months, SR was detected in 129 (27.5 %) patients after the index EVAR. Compared with never smokers, current smokers were more likely to experience SR (adjusted HR 2.630, p < .001), while former smokers did not show any significant difference. Multivariate Cox regression also showed that maximal aneurysm diameter (adjusted HR 1.012, p = 0.035) and female (adjusted HR 1.675, p = .045) were independent predictors of SR. A total of 51 (10.9 %) patients had MaSR at a median time of 15.4 months after EVAR. In multivariate analysis, maximal aneurysm diameter and Zenith stent graft were independently associated with MaSR.

CONCLUSION

In Chinese population, the incidence of SR and MaSR was 27.5 % and 10.9 % after EVAR, respectively. Maximal aneurysm diameter and female were independent predictors of SR. Compared with never smokers, it was more likely to have SR in current smokers.

Type II endoleaks after fenestrated/branched endografting for juxtarenal and pararenal aortic aneurysms

OBJECTIVE

Persistent type II endoleaks (pEL2s) are not uncommon after endovascular aneurysm repair and their impact on long-term outcomes is well-documented. However, their occurrence and natural history after fenestrated/branched endografting (F/B-EVAR) for juxtarenal and pararenal aneurysms (J/P-AAAs) have been scarcely investigated. Aim of this study was to report incidence, risk factors, and natural history of pEL2 after F/B-EVAR in J/P-AAAs.

METHODS

Between 2016 and 2022, all J/P-AAAs undergoing F/B-EVAR were prospectively collected and retrospectively analyzed. EL2 were assessed at the completion angiography, at 30 days and after 6 months as primary outcomes. Preoperative risk factors for pEL2, follow-up survival, freedom from reinterventions (FFR) and aneurysm shrinkage (≥5 mm) were considered as secondary outcomes.

RESULTS

Of 132 patients, there were 88 (67%) JAAAs and 44 (33%) PAAAs. Seventeen EL2 (13%) were detected at the completion angiography and 36 (27%) at 30-day computed tomography angiography. The mean follow-up was 28 ± 23 months. Eleven (31%) EL2 sealed spontaneously within 6 months and three new cases were detected, for an overall of 28 pEL2/107 patients (26%) with available radiological follow-up of ≥6 months. Preoperative antiplatelet therapy (odds ratio, 4.7; 95% confidence interval [CI[, 1-22.1; P = .05), aneurysm thrombus volume of ≤40% and six or more patent aneurysm afferent vessels (odds ratio, 7.2; 95% CI, 1.8-29.1; P = .005) were independent risk factors for pEL2. The estimated 3-year survival was 80%, with no difference between cases with and without pEL2 (78% vs 85%; P = .08). The estimated 3-year FFR was 86%, with no difference between cases with and without pEL2 (81% vs 87%; P = .41). Four cases (3%) of EL2-related reinterventions were performed. In 65 cases (49%), aneurysm shrinkage was detected. pEL2 was an independent risk factor for absence of aneurysm shrinkage during follow-up (hazard ratio, 3.2; 95% CI, 1.2-8.3; P = .014). Patients without shrinkage had lower follow-up survival (64% vs 86% at 3-year; P = .009) and FFR (74% vs 90% at 3 years; P = .014) than patients with shrinkage.

CONCLUSIONS

PEL2 is not infrequent (26%) after F/B-EVAR for J/P-AAAs and is correlated with preoperative antiplatelet therapy, aneurysm thrombus volume of ≤40%, and six or more patent sac afferent vessels. Patients with pEL2 have a diminished aneurysm shrinkage, which is correlated with lower follow-up survival and FFR compared with patients with aneurysm shrinkage.

Aneurysm sac shrinkage at 1 year after fenestrated-branched endovascular aortic repair of complex aortic aneurysms offers mid-term survival advantage

OBJECTIVES

To investigate the impact of 1-year changes in aneurysm sac diameter on patient survival after fenestrated-branched endovascular aortic repair (FB-EVAR) of complex abdominal aortic aneurysms or thoracoabdominal aortic aneurysms.

METHODS

We reviewed the clinical data of patients enrolled in a prospective nonrandomized study investigating FB-EVAR (2013-2022). Patients with sequential follow up computed tomography scans at baseline and 6 to 18 months after FB-EVAR were included in the analysis. Aneurysm sac diameter change was defined as the difference in maximum aortic diameter from baseline measurements obtained in centerline of flow. Patients were classified as those with sac shrinkage (≥5 mm) or failure to regress (<5 mm or expansion) according to sac diameter change. The primary end point was all-cause mortality. Secondary end points were aortic-related mortality (ARM), aortic aneurysm rupture (AAR), and aorta-related secondary intervention.

RESULTS

There were 549 patients treated by FB-EVAR. Of these, 463 patients (71% male, mean age, 74 ± 8 years) with sequential computed tomography imaging were investigated. Aneurysm extent was thoracoabdominal aortic aneurysms in 328 patients (71%) and abdominal aortic aneurysms in 135 (29%). Sac shrinkage occurred in 270 patients (58%) and failure to regress in 193 patients (42%), including 19 patients (4%) with sac expansion at 1 year. Patients from both groups had similar cardiovascular risk factors, except for younger age among patients with sac shrinkage (73 ± 8 years vs 75 ± 8 years; P < .001). The median follow-up was 38 months (interquartile range, 18-51 months). The 5-year survival estimate was 69% ± 4.1% for the sac shrinkage group and 46% ± 6.2% for the failure to regress group. Survival estimates adjusted for confounders (age, chronic pulmonary obstructive disease, chronic kidney disease, congestive heart failure, and aneurysm extent) revealed a higher hazard of late mortality in patients with failure to regress (adjusted hazard ratio, 1.72; 95% confidence interval, 1.18-2.52; P = .005). The 5-year cumulative incidences of ARM (1.1% vs 3.1%; P = .30), AAR (0.6% vs 2.6%; P = .20), and aorta-related secondary intervention (17.0% ± 2.8% vs 19.0% ± 3.8%) were both comparable between the groups.

CONCLUSIONS

Aneurysm sac shrinkage at 1 year is common after FB-EVAR and is associated with improved patient survival, whereas sac enlargement affects only a minority of patients. The low incidences of ARM and AAR indicate that failure to regress may serve as a surrogate marker for nonaortic-related death.

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.

Biomechanics and Early Sac Regression after Endovascular Aneurysm Repair of Abdominal Aortic Aneurysm

Background

Sac regression after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA) is regarded as a marker of successful response to treatment. Several factors influence sac behavior after EVAR, yet little is known about the value of preoperative biomechanics. The aim of this study was to investigate the difference in aortic biomechanics between patients with and without sac regression.

Methods

Patients treated with standard EVAR for infrarenal AAA at the Karolinska University Hospital between 2009 and 2012 with one preoperative and a minimum of two postoperative computed tomography angiography (CTA) scans were considered for inclusion in this single-center retrospective cohort study. Biomechanical indices such as AAA wall stress and wall stress-strength ratio as well as intraluminal thrombus (ILT) thickness and stress were measured preoperatively in A4ClinicRE (VASCOPS GmbH). AAA diameter and volume were analyzed on preoperative, 30-day, and 1-year CTAs. Patients were dichotomized based on sac regression, defined as a ≥ 5 mm decrease in maximal AAA diameter between the first two postoperative CTA scans. Multivariable logistic regression was used for analysis of factors associated with early sac regression.

Results

Of the 101 patients treated during the inclusion period, 64 were included. Thirty-nine (61%) demonstrated sac regression and 25 (39%) had a stable sac or sac increase. The mean patients age (73 years vs 76 years), male sex (85% vs 96%), and median AAA diameter (58 mm vs 58.5 mm) did not differ between patients with and without sac regression. Although no difference in preoperative biomechanics was seen between the groups, multivariable logistic regression revealed that a larger AAA diameter (odds ratio [OR], 1.27; 95% confidence interval [CI], 1.06-1.51; P = .009) and smoking (OR, 22.1; 95% CI, 2.78-174; P = .003) were positively associated with sac regression. In contrast, the lumen diameter (OR, 0.87; 95% CI, 0.77-0.98; P = .023), ILT thickness (OR, 0.85; 95% CI, 0.75-0.97; P = .013), aspirin or direct-acting oral anticoagulant use (OR, 0.11; 95% CI, 0.02-0.61; P = .012), and mean ILT stress (OR, 0.35; 95% CI, 0.14-0.87; P = .024) showed a negative association. Patients with sac regression had fewer reinterventions (log-rank P = .010) and lower mortality (log-rank P = .012) at the 5-year follow-up.

Conclusions

This study, characterizing preoperative biomechanics in patients with and without sac regression, demonstrated a negative association between mean ILT stress and ILT thickness with a change in sac diameter after EVAR. Given that the ILT is a highly dynamic entity, further studies focusing on the role of the thrombus are needed. Furthermore, patients presenting with early sac regression had improved outcomes after EVAR.