One-year aneurysm-sac dynamics are associated with reinterventions and rupture following infrarenal endovascular aneurysm repair.

OBJECTIVE: One-year aneurysm sac changes have previously been found to be associated with mortality and may have the potential to guide personalized follow-up following endovascular aneurysm repair (EVAR). In this study, we examined the association of these early sac changes with long-term reintervention and rupture. METHODS: We identified all patients undergoing first-time EVAR for intact abdominal aortic aneurysm between 2003 and 2018 in the Vascular Quality Initiative with linkage to Medicare claims for long-term outcomes. We included patients with an imaging study at 1 year postoperatively. Aneurysm sac behavior was defined as per the Society for Vascular Surgery guidelines: stable sac (<5 mm change), sac regression (≥5 mm), and sac expansion (≥5 mm). Outcomes included mortality, reintervention, and rupture within 8 years, which were assessed with Kaplan-Meier methods and multivariable Cox regression analysis. Secondarily, we utilized polynomial spline interpolation to demonstrate the continuous relationship of diameter change to 8-year hazard of reintervention, rupture, or mortality as a composite outcome. RESULTS: Of 31,185 EVAR patients, 16,102 (52%) had an imaging study at 1 year and were included in this study. At 1 year, 44% of sacs remained stable, 49% regressed, and 6.2% displayed expansion. Following risk adjustment, compared with a stable sac at 1 year, sac regression was associated with lower 8-year mortality (49% vs 53%; hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.85-0.99; P = .036), reintervention rate (8.9% vs 15%; HR, 0.58; 95% CI, 0.50-0.68; P < .001), and rupture rate (2.0% vs 4.0%; HR, 0.45; 95%CI, 0.29-0.69; P < .001). Conversely, compared with a stable sac, sac expansion was associated with higher 8-year mortality (64% vs 53%; HR, 1.31; 95% CI, 1.14-1.51; P < .001) and reintervention rate (27% vs 15%; HR, 1.98; 95% CI, 1.57-2.51; P < .001), but similar risk of rupture (7.2% vs 4.0%; HR, 1.61; 95% CI, 0.88-2.96; P = .12). Polynomial spline interpolation demonstrated that, compared with no diameter change at 1 year, increased sac regression was associated with an incrementally lower risk of late outcomes, whereas increased sac expansion was associated with an incrementally higher risk of late outcomes. CONCLUSIONS: Following EVAR, compared with a stable sac at 1-year imaging, sac regression and expansion are associated with a lower and higher risk respectively of long-term mortality, reinterventions, and ruptures. Moreover, the amount of regression or expansion seems to be incrementally associated with these late outcomes, too. Future studies are needed to determine how to improve 1-year sac regression, and whether it is safe to extend follow-up intervals for patients with regressing sacs.

The association between sex and outcomes after thoracic endovascular repair for acute type B aortic dissection.

OBJECTIVE: Prior literature has found worse outcomes for female patients after endovascular repair of abdominal aortic aneurysm and mixed findings after thoracic endovascular aortic repair (TEVAR) for thoracic aortic aneurysm. However, the influence of sex on outcomes after TEVAR for acute type B aortic dissection (aTBAD) is not fully elucidated. METHODS: We identified patients who underwent TEVAR for aTBAD (<30 days) in the Vascular Quality Initiative from 2014 to 2022. We excluded patients with an entry tear or stent seal within the ascending aorta or aortic arch and patients with an unknown proximal tear location. Included patients were stratified by biological sex, and we analyzed perioperative outcomes and 5-year mortality with multivariable logistic regression and Cox regression analysis, respectively. Furthermore, we analyzed adjusted variables for interaction with female sex. RESULTS: We included 1626 patients, 33% of whom were female. At presentation, female patients were significantly older (65 [interquartile range: 54, 75] years vs 56 [interquartile range: 49, 68] years; P = .01). Regarding indications for repair, female patients had higher rates of pain (85% vs 80%; P = .02) and lower rates of malperfusion (23% vs 35%; P < .001), specifically mesenteric, renal, and lower limb malperfusion. Female patients had a lower proportion of proximal repairs in zone 2 (39% vs 48%; P < .01). After TEVAR for aTBAD, female sex was associated with comparable odds of perioperative mortality to males (8.1 vs 9.2%; adjusted odds ratio [aOR]: 0.79 [95% confidence interval (CI): 0.51-1.20]). Regarding perioperative complications, female sex was associated with lower odds for cardiac complications (2.3% vs 4.7%; aOR: 0.52 [95% CI: 0.26-0.97]), but all other complications were comparable between sexes. Compared with male sex, female sex was associated with similar risk for 5-year mortality (26% vs 23%; adjusted hazard ratio: 1.01 [95% CI: 0.77-1.32]). On testing variables for interaction with sex, female sex was associated with lower perioperative and 5-year mortality at older ages relative to males (aOR: 0.96 [0.93-0.99] | adjusted hazard ratio: 0.97 [0.95-0.99]) and higher odds of perioperative mortality when mesenteric malperfusion was present (OR: 2.71 [1.04-6.96]). CONCLUSIONS: Female patients were older, less likely to have complicated dissection, and had more distal proximal landing zones. After TEVAR for aTBAD, female sex was associated with similar perioperative and 5-year mortality to male sex, but lower odds of in-hospital cardiac complications. Interaction analysis showed that females were at additional risk for perioperative mortality when mesenteric ischemia was present. These data suggest that TEVAR for aTBAD overall has a similar safety profile in females as it does for males.

Surgeon volume and outcomes following thoracic endovascular aortic repair for blunt thoracic aortic injury.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) for blunt thoracic aortic injury (BTAI) at high-volume hospitals has previously been associated with lower perioperative mortality, but the impact of annual surgeon volume on outcomes following TEVAR for BTAI remains unknown. METHODS: We analyzed Vascular Quality Initiative (VQI) data from patients with BTAI that underwent TEVAR between 2013 and 2023. Annual surgeon volumes were computed as the number of TEVARs (for any pathology) performed over a 1-year period preceding each procedure and were further categorized into quintiles. Surgeons in the first volume quintile were categorized as low volume (LV), the highest quintile as high volume (HV), and the middle three quintiles as medium volume (MV). TEVAR procedures performed by surgeons with less than 1-year enrollment in the VQI were excluded. Using multilevel logistic regression models, we evaluated associations between surgeon volume and perioperative outcomes, accounting for annual center volumes and adjusting for potential confounders, including aortic injury grade and severity of coexisting injuries. Multilevel models accounted for the nested clustering of patients and surgeons within the same center. Sensitivity analysis excluding patients with grade IV BTAI was performed. RESULTS: We studied 1321 patients who underwent TEVAR for BTAI (28% by LV surgeons [0-1 procedures per year], 52% by MV surgeons [2-8 procedures per year], 20% by HV surgeons [≥9 procedures per year]). With higher surgeon volume, TEVAR was delayed more (in <4 hours: LV: 68%, MV: 54%, HV: 46%; P < .001; elective (>24 hours): LV: 5.1%; MV: 8.9%: HV: 14%), heparin administered more (LV: 80%, MV: 81%, HV: 87%; P = .007), perioperative mortality appears lower (LV: 11%, MV: 7.3%, HV: 6.5%; P = .095), and ischemic/hemorrhagic stroke was lower (LV: 6.5%, MV: 3.6%, HV: 1.5%; P = .006). After adjustment, compared with LV surgeons, higher volume surgeons had lower odds of perioperative mortality (MV: 0.49; 95% confidence interval [CI], 0.25-0.97; P = .039; HV: 0.45; 95% CI, 0.16-1.22; P = .12; MV/HV: 0.50; 95% CI, 0.26-0.96; P = .038) and ischemic/hemorrhagic stroke (MV: 0.38; 95% CI, 0.18-0.81; P = .011; HV: 0.16; 95% CI, 0.04-0.61; P = .008). Sensitivity analysis found lower adjusted odds for perioperative mortality (although not significant) and ischemic/hemorrhagic stroke for higher volume surgeons. CONCLUSIONS: In patients undergoing TEVAR for BTAI, higher surgeon volume is independently associated with lower perioperative mortality and postoperative stroke, regardless of hospital volume. Future studies could elucidate if TEVAR for non-ruptured BTAI might be delayed and allow stabilization, heparinization, and involvement of a higher TEVAR volume surgeon.

The rise of endovascular repair for abdominal, thoracoabdominal, and thoracic aortic aneurysms.

BACKGROUND: Given changes in intervention guidelines and the growing popularity of endovascular treatment for aortic aneurysms, we examined the trends in admissions and repairs of abdominal aortic aneurysms (AAAs), thoracoabdominal aortic aneurysms (TAAAs), and thoracic aortic aneurysms (TAAs). METHODS: We identified all patients admitted with ruptured aortic aneurysms and intact aortic aneurysms repaired in the Nationwide Inpatient Sample between 2004 and 2019. We then examined the use of open, endovascular, and complex endovascular repair (OAR, EVAR, and cEVAR) for each aortic aneurysm location (AAA, TAAA, and TAA), alongside their resulting in-hospital mortality, over time. cEVAR included branched, fenestrated, and physician-modified endografts. RESULTS: 715,570 patients were identified with AAA (87% intact repairs and 13% rupture admissions). Both intact AAA repairs and ruptured AAA admissions decreased significantly between 2004 and 2019 (intact 41,060-34,215, P < .01; ruptured 7175-4625, P = .02). Of all AAA repairs performed in a given year, the use of EVAR increased (2004-2019: intact 45%-66%, P < .01; ruptured 10%-55%, P < .01) as well as cEVAR (2010-2019: intact 0%-23%, P < .01; ruptured 0%-14%, P < .01). Mortality after EVAR of intact AAAs decreased significantly by 29% (2004-2019, 0.73%-0.52%, P < .01), whereas mortality after OAR increased significantly by 16% (2004-2019, 4.4%-5.1%, P < .01). In the study, 27,443 patients were identified with TAAA (80% intact and 20% ruptured). In the same period, intact TAAA repairs trended upward (2004-2019, 1435-1640, P = .055), and cEVAR became the most common approach (2004-2019, 3.8%-72%, P = .055). A total of 141,651 patients were identified with ascending, arch, or descending TAAs (90% intact and 10% ruptured). Intact TAA repairs increased significantly (2004-2019, 4380-10,855, P < .01). From 2017 to 2019, the mortality after OAR of descending TAAs increased and mortality after thoracic endovascular aneurysm repair decreased (2017-2019, OAR 1.6%-3.1%; thoracic endovascular aneurysm repair 5.2%-3.8%). CONCLUSIONS: Both intact AAA repairs and ruptured AAA admissions significantly decreased between 2004 and 2019. The use of endovascular techniques for the repair of all aortic aneurysm locations, both intact and ruptured, increased over the past two decades. Most recently in 2019, 89% of intact AAA repairs, infrarenal through suprarenal, were endovascular (EVAR or cEVAR, respectively). cEVAR alone increased to 23% of intact AAA repairs in 2019, from 0% a decade earlier. In this period of innovation, with many new options to repair aortic aneurysms while maintaining arterial branches, endovascular repair is now used for the majority of all intact aortic aneurysm repairs. Long-term data are needed to evaluate the durability of these procedures.

Association between diabetes status and long-term outcomes following open and endovascular repair of infrarenal abdominal aortic aneurysms.

OBJECTIVE: Current literature reports conflicting findings regarding the effect of diabetes mellitus (DM) on outcomes of abdominal aortic aneurysm (AAA) repair. In this study we examined the effect of DM and its management on outcomes after open AAA repair (OAR) and endovascular AAA repair (EVAR). METHODS: We identified all patients undergoing OAR or EVAR for infrarenal AAA between 2003 and 2018 in the Vascular Quality Initiative registry data linked with Medicare claims. We excluded patients with missing DM status. Patients were stratified by their preoperative DM status, and then further stratified by DM management: dietary, noninsulin antidiabetic medications (NIMs), or insulin. Outcomes of interest included 1-year aneurysm sac dynamics, 8-year aneurysm rupture, reintervention, and all-cause mortality. These outcomes were analyzed with the χ2 test, Kaplan-Meier methods, and multivariable Cox regression analyses. RESULTS: We identified 34,021 EVAR patients and 4127 OAR patients, of whom 20% and 16% had DM, respectively. Of all DM patients, 22% were managed by dietary management, 59% by NIM, and 19% by insulin. After EVAR, DM patients were more likely to have stable sacs, whereas non-DM patients were more likely to have sac regression at 1 year. Compared with non-DM, DM was associated with a significantly lower risk for 8-year rupture in EVAR (EVAR hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.51-0.92). Compared with non-DM, NIM was associated with lower risk of rupture within 8-years for both EVAR and OAR (EVAR HR, 0.64; 95% CI, 0.44-0.94; OAR HR, 0.29; 95% CI, 0.41-0.80), whereas dietary control and insulin had a similar rupture risk compared with non-DM. However, compared with non-DM, DM was associated with a higher risk of 8-year all-cause mortality after EVAR and OAR (DM vs non-DM: EVAR HR, 1.17; 95% CI, 1.11-1.23; OAR HR, 1.16; 95% CI, 1.00-1.36). After further DM management substratification, compared with non-DM, management with NIM and insulin were associated with a higher 8-year mortality in EVAR and OAR (EVAR: NIM HR, 1.12; 95% CI, 1.05-1.20; insulin: HR, 1.40; 95% CI, 1.26-1.55; OAR: NIM HR, 1.27; 95% CI, 1.06-1.54; and insulin: HR, 1.57; 95% CI, 1.15-2.13). Finally, there was a similar risk of reintervention across the DM and non-DM populations for EVAR and OAR. CONCLUSIONS: DM was associated with a lower adjusted risk of rupture after EVAR as well as OAR in patients managed with NIM. Nevertheless, just as in patients without AAA, preoperative DM was associated with a higher adjusted risk of all-cause mortality. Further study is needed to evaluate for differences in aneurysm-related mortality between DM and non-DM patients, and studies are planned to evaluate the independent effect of NIM on aneurysm-related outcomes.

Comparison of Open and Endovascular Repair of Complex Abdominal Aortic Aneurysms.

OBJECTIVE: To compare perioperative and 5-year outcomes following endovascular (FEVAR) and open repair (OAR) of complex abdominal aortic aneurysms (cAAA) in males and females separately, given the known sex related differences in perioperative outcomes. METHODS: We studied all elective cAAA repairs between 2014-2019 in the Vascular Implant Surveillance and Interventional Outcomes Network (VISION) registry. We stratified patients based on sex. We calculated propensity scores for assignment to either OAR or FEVAR. Covariates including age, race, diameter, baseline comorbidities, proximal extent of repair, annual center volumes, and annual surgeon volumes were introduced into the model for estimating propensity scores. Within matched cohorts, perioperative outcomes and 5-year outcomes (mortality, reinterventions, and ruptures) were evaluated using multivariable logistic and Cox regression models. RESULTS: We identified 2,825 patients of whom 29% were female. Within both the sexes, OAR was more commonly performed (OAR vs FEVAR: males: 53% vs 47%; females: 63% vs 37%). After matching, among males (n=1326), FEVAR was associated with lower perioperative mortality (FEVAR vs OAR: 2.3% vs 5.1%; p<.001). However, FEVAR was associated with comparable 5-year mortality (38% vs 28%; hazard ratio (HR) 1.2 [0.92-1.4]; p=.22) and a higher hazard of 5-year reintervention (19% vs 3.7%; aHR: 4.5 [2.6-7.6], p<.001). Among females (n=456), FEVAR and OAR showed similar perioperative mortality (8.3% vs 7.0%; p=.73). At 5 years, FEVAR was associated with higher hazards of mortality (43% vs 32%; aHR: 1.5 [1.03-2.2], p=.034) and reintervention (20% vs 3.0%; aHR: 4.8 [2.1-11], p<.001) compared with OAR. CONCLUSIONS: Among males, FEVAR was associated with favorable perioperative outcomes compared with OAR, though these advantages attenuate over time. However, among females, FEVAR was associated with similar perioperative outcomes, eventually leading to higher reinterventions and possibly higher mortality within 5 years. Future efforts should focus on determining the factors associated with these sex disparities to improve outcomes following FEVAR in females. Based on current evidence, females undergoing elective cAAA repair should be selected with due caution, especially for endovascular repair.

Retroperitoneal vs transperitoneal approach for nonruptured open conversion after endovascular aneurysm repair.

OBJECTIVE: Several studies comparing the transperitoneal (TP) and retroperitoneal (RP) approach for abdominal aortic aneurysm (AAA) repair suggest that the RP approach may result in lower rates of perioperative mortality and morbidity. However, data comparing these approaches for open conversion are lacking. This study aims to evaluate the association between the type of approach and outcomes following open conversion after endovascular aneurysm repair (EVAR). METHODS: We included all patients who underwent open conversion after EVAR between 2010 and 2022 in the Vascular Quality Initiative. Patients presenting with rupture were excluded. The primary outcome was perioperative mortality. The secondary outcomes included perioperative complications and 5-year mortality. Inverse probability weighting was used to adjust for factors with statistical or clinical significance. Logistic regression was used to assess perioperative mortality and complications in the weighted cohort. The 5-year mortality was evaluated using Kaplan-Meier and Cox regression. RESULTS: We identified 660 patients (39% RP) who underwent open conversion after EVAR. Compared with TP, RP patients were older (75 years [interquartile range, 70-79 years] vs 73.5 years [interquartile range, 68-79 years]; P < .001), and more frequently had prior myocardial infarction (33% vs 22%; P = .002). Compared with the TP approach, the RP approach was used less frequently in cases of associated iliac aneurysm (19% vs 27%; P = .026), but more frequently with associated renal bypass (7.8% vs 1.7%; P < .001) and by high-volume physicians (highest quintile, >7 AAA annually: 41% vs 17%; P < .001) and in high-volume centers (highest quintile, >35 AAA annually: 36% vs 20%; P < .001). RP patients, compared with TP patients, were less likely to have external iliac or femoral distal anastomosis (8.2% vs 21%; P < .001), and an infrarenal clamp (25% vs 36%; P < .001). Unadjusted perioperative mortality was not significantly different between approaches (RP vs TP: 3.8% vs 7.5%; P = .077). After risk adjustment, RP patients had similar odds of perioperative mortality (adjusted odds ratio [aOR], 0.49; 95% confidence interval [CI], 0.22-1.10; P = .082), and lower odds of intestinal ischemia (aOR, 0.26; 95% CI, 0.08-0.86; P = .028) and in-hospital reintervention (aOR, 0.43; 95% CI, 0.22-0.85; P = .015). No significant differences were found in the other perioperative complications or 5-year mortality (aHR, 0.79; 95% CI, 0.47-1.32; P = .37). CONCLUSIONS: Our findings suggest that the RP approach may be associated with a lower adjusted odds of perioperative complications compared with the TP approach. The RP approach should be considered for open conversion after EVAR when feasible.

The impact of urgency of repair on outcomes following thoracic endovascular aortic repair for blunt thoracic aortic injury.

OBJECTIVE: Current societal recommendations regarding the timing of thoracic endovascular aortic repair (TEVAR) for blunt thoracic aortic injury (BTAI) vary. Prior studies have shown that elective repair was associated with lower mortality after TEVAR for BTAI. However, these studies lacked data such as Society for Vascular Surgery (SVS) aortic injury grades and TEVAR-related postoperative outcomes. Therefore, we used the Vascular Quality Initiative registry, which includes relevant anatomic and outcome data, to examine the outcomes following urgent/emergent (≤ 24 hours) vs elective TEVAR for BTAI. METHODS: Patients undergoing TEVAR for BTAI between 2013 and 2022 were included, excluding those with SVS grade 4 aortic injuries. We included covariates such as age, sex, race, transfer status, body mass index, preoperative hemoglobin, comorbidities, medication use, SVS aortic injury grade, coexisting injuries, Glasgow Coma Scale, and prior aortic surgery in a regression model to compute propensity scores for assignment to urgent/emergent or elective TEVAR. Perioperative outcomes and 5-year mortality were evaluated using inverse probability-weighted logistic regression and Cox regression, also adjusting for left subclavian artery revascularization/occlusion and annual center and physician volumes. RESULTS: Of 1016 patients, 102 (10%) underwent elective TEVAR. Patients who underwent elective repair were more likely to undergo revascularization of the left subclavian artery (31% vs 7.5%; P < .001) and receive intraoperative heparin (94% vs 82%; P = .002). After inverse probability weighting, there was no association between TEVAR timing and perioperative mortality (elective vs urgent/emergent: 3.9% vs 6.6%; odds ratio [OR], 1.1; 95% confidence interval [CI], 0.27-4.7; P = .90) and 5-year mortality (5.8% vs 12%; hazard ratio [HR], 0.95; 95% CI, 0.21-4.3; P > .9).Compared with urgent/emergent TEVAR, elective repair was associated with lower postoperative stroke (1.0% vs 2.1%; adjusted OR [aOR], 0.12; 95% CI, 0.02-0.94; P = .044), even after adjusting for intraoperative heparin use (aOR, 0.12; 95% CI, 0.02-0.92; P = .042). Elective TEVAR was also associated with lower odds of failure of extubation immediately after surgery (39% vs 65%; aOR, 0.18; 95% CI, 0.09-0.35; P < .001) and postoperative pneumonia (4.9% vs 11%; aOR, 0.34; 95% CI, 0.13-0.91; P = .031), but comparable odds of any postoperative complication as a composite outcome and reintervention during index admission. CONCLUSIONS: Patients with BTAI who underwent elective TEVAR were more likely to receive intraoperative heparin. Perioperative mortality and 5-year mortality rates were similar between the elective and emergent/urgent TEVAR groups. Postoperatively, elective TEVAR was associated with lower ischemic stroke, pulmonary complications, and prolonged hospitalization. Future modifications in society guidelines should incorporate the current evidence supporting the use of elective TEVAR for BTAI. The optimal timing of TEVAR in patients with BTAI and the factors determining it should be the subject of future study to facilitate personalized decision-making.

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.

An international, expert-based, Delphi consensus document on controversial issues in the management of abdominal aortic aneurysms.

OBJECTIVE: As a result of conflicting, inadequate or controversial data in the literature, several issues concerning the management of patients with abdominal aortic aneurysms (AAAs) remain unanswered. The aim of this international, expert-based Delphi consensus document was to provide some guidance for clinicians on these controversial topics. METHODS: A three-round Delphi consensus document was produced with 44 experts on 6 prespecified topics regarding the management of AAAs. All answers were provided anonymously. The response rate for each round was 100%. RESULTS: Most participants (42 of 44 [95.4%]) agreed that a minimum case volume per year is essential (or probably essential) for a center to offer open or endovascular AAA repair (EVAR). Furthermore, 33 of 44 (75.0%) believed that AAA screening programs are (probably) still clinically effective and cost effective. Additionally, most panelists (36 of 44 [81.9%]) voted that surveillance after EVAR should be (or should probably be) lifelong. Finally, 35 of 44 participants (79.7%) thought that women smokers should (or should probably/possibly) be considered for screening at 65 years of age, similar to men. No consensus was achieved regarding lowering the threshold for AAA repair and the need for deep venous thrombosis prophylaxis in patients undergoing EVAR. CONCLUSIONS: This expert-based Delphi consensus document provides guidance for clinicians regarding specific unresolved issues. Consensus could not be achieved on some topics, highlighting the need for further research in those areas.

An Expert Delphi Consensus on Risk Factors for Adverse Events After Endovascular Aortic Aneurysm Repair: Tier 1 Study From the International RIsk Stratification in EVAR (IRIS-EVAR) Working Group.

PURPOSE: Tier 1 of the International RIsk Stratification in EndoVascular Aneurysm Repair (IRIS-EVAR) project aimed to identify important risk factors for adverse events following endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: Initially, the steering committee proposed a number of risk factors for adverse events following EVAR. A Delphi consensus was performed as expert panelists were presented with risk factors and provided the opportunity to propose additional risk factors during the process. Experts in EVAR completed an online survey via 3 structured rounds. The first round opened in July 2022, and the third round closed in December 2022. Panelists rated risk factors using a 4-point Likert scale. Consensus was defined as >70% of participants agreeing/strongly agreeing or disagreeing/strongly disagreeing with a statement in each round. RESULTS: Thirty-five panelists from 12 countries completed the 3 rounds of surveys. Of a total of 64 individual risk factors assessed by the panelists, 37 (58%) had consensus that they were important for adverse events following EVAR. Risk factors were stratified in 4 domains: 14 (38%) were related to preoperative anatomy, 3 (8%) related to the aortic device selection, 8 (22%) related to the procedure performance, and 12 (32%) related to postoperative surveillance. Factors with the highest consensus in each domain were as follows: proximal aortic neck length <15 mm (98% consensus), anatomy non-compliant with instructions for use (94% consensus), length of achieved proximal aortic neck post implantation <10 mm (98% consensus), and non-satisfactory seal at landing or overlapping zones/sac expansion/kink or stenosis (100% consensus each), respectively. CONCLUSIONS: Clinically important risk factors for adverse events after EVAR were identified via expert consensus. These factors will be used to develop an expert consensus-informed risk stratification and surveillance strategies. CLINICAL IMPACT: This is the first study to apply an in-depth Delphi methodology to achieve an expert consensus on risk factors for adverse events after endovascular aneurysm repair (EVAR). Important risk factors were stratified in 4 domains: preoperative anatomy (14 factors), aortic device (3 factors), EVAR procedure (8 factors), and postoperative surveillance (12 factors). This study will potentially influence future clinical practice by providing evidence informed by experts regarding predictors of adverse events following EVAR that can be taken into account during decision making and developing post-EVAR surveillance strategies. These findings will inform a risk stratification tool for everyday use by vascular surgeons.

Metformin Use and Long-term Outcomes Including Aneurysm Sac Dynamics Following EVAR for Infrarenal Abdominal Aortic Aneurysm: "A Retrospective Study".

PURPOSE: Metformin, widely used for the treatment of diabetes mellitus (DM), has shown potential for inhibiting abdominal aortic aneurysm (AAA) growth by reducing extracellular matrix remodeling and inflammation. However, its influence on clinical outcomes and aneurysm sac dynamics after endovascular aneurysm repair (EVAR) remains uncertain. This retrospective study aims to explore the effects of metformin on long-term outcomes following EVAR. MATERIALS AND METHODS: Patients who underwent elective standard EVAR for infrarenal AAA at a single academic Dutch hospital from 2000 to 2022 were included. We collected baseline patient demographics, comorbid conditions, anatomical and operative characteristics, and 30-day postoperative events. Metformin use was defined as using it preceding EVAR. The primary outcome, the postoperative aneurysm sac volume over time, was investigated using linear mixed-effects modeling. The secondary outcomes, 8-year all-cause mortality and freedom from graft-related events, were evaluated using Kaplan-Meier methods. RESULTS: We analyzed 685 patients, including 634 (93%) non-metformin users and 51 (7%) metformin users. The median follow-up period was similar (4.0 years [IQR=1.5, 6.5] vs 5.0 years [IQR=2.0, 8.0]; p=0.091). Patients on metformin had a preoperative aneurysm sac volume of 153 cc (IQR=114, 195) compared with 178 cc (IQR=133, 240) for non-metformin patients (p=0.054). At 30 days post-EVAR, metformin patients had a comparable mean aneurysm sac volume compared with non-metformin patients (metformin: -19.4 cc [95% confidence interval [CI]: -47.4, 8.5]; p=0.173). The effect of metformin on aneurysm growth over time was not significant (-3.9 cc/year; [95% CI: -22.7, 14.9]; p=0.685). Following risk-adjusted analysis, metformin use was associated with similar rates of all-cause mortality (metformin vs no metformin: 50% vs 44%; hazard ratio [HR]=1.11, 95% CI: 0.66, 1.88; p=0.688) and freedom from graft-related events (metformin vs no metformin: 63% vs 66%; HR=1.82, 95% CI: 0.98, 3.38; p=0.059). CONCLUSION: Although metformin use may reduce preoperative AAA growth, it does not seem to influence overall/long-term post-EVAR AAA sac dynamics, all-cause mortality, or freedom from graft-related events. These findings suggest that the potential protective effect of metformin on AAA may not be sustained after EVAR. Further prospective studies are needed to investigate the mechanisms underlying the potential role of metformin in AAA management following EVAR. CLINICAL IMPACT: There is currently no approved pharmacological treatment available to slow the abdominal aortic aneurysm (AAA) growth rate and reduce the related risk of rupture. In our retrospective analysis including 685 patients undergoing EVAR for infrarenal AAA, we found that metformin use was not associated with improved post-EVAR outcomes, such as a reduction of aneurysm sac volume over time, eight-year all-cause mortality, or freedom of graft-related events. These findings suggest that the potential protective effect of metformin on AAA may not be sustained after EVAR and underscore the need for ongoing research into this area.

Volume Measurements for Surveillance after Endovascular Aneurysm Repair using Artificial Intelligence.

OBJECTIVE: Surveillance after endovascular aneurysm repair (EVAR) is suboptimal due to limited compliance and relatively large variability in measurement methods of abdominal aortic aneurysm (AAA) sac size after treatment. Measuring volume offers a more sensitive early indicator of aneurysm sac growth or regression and stability, but is more time consuming and thus less practical than measuring maximum diameter. This study evaluated the accuracy and consistency of the artificial intelligence (AI) driven software PRAEVAorta 2 and compared it with an established semi-automated segmentation method. METHODS: Post-EVAR aneurysm sac volumes measured by AI were compared with a semi-automated segmentation method (3mensio software) in patients with an infrarenal AAA, focusing on absolute aneurysm volume and volume evolution over time. The clinical impact of both methods was evaluated by categorising patients as showing either AAA sac regression, stabilisation, or growth comparing the 30 day and one year post-EVAR computed tomography angiography (CTA) images. Inter- and intra-method agreement were assessed using Bland-Altman analysis, the intraclass correlation coefficient (ICC), and Cohen's κ statistic. RESULTS: Forty nine patients (98 CTA images) were analysed, after excluding 15 patients due to segmentation errors by AI owing to low quality CT scans. Aneurysm sac volume measurements showed excellent correlation (ICC = 0.94, 95% confidence interval [CI] 0.88 - 0.99) with good to excellent correlation for volume evolution over time (ICC = 0.85, 95% CI 0.75 - 0.91). Categorisation of AAA sac evolution showed fair correlation (Cohen's κ = 0.33), with 12 discrepancies (24%) between methods. The intra-method agreement for the AI software demonstrated perfect consistency (bias = -0.01 cc), indicating that it is more reliable compared with the semi-automated method. CONCLUSION: Despite some differences in AAA sac volume measurements, the highly consistent AI driven software accurately measured AAA sac volume evolution. AAA sac evolution classification appears to be more reliable than existing methods and may therefore improve risk stratification post-EVAR, and could facilitate AI driven personalised surveillance programmes. While high quality CTA images are crucial, considering radiation exposure is important, validating the software with non-contrast CT scans might reduce the radiation burden.

Long Term Outcomes of the Gore Excluder Low Permeability Endoprosthesis for the Treatment of Infrarenal Aortic Aneurysms.

OBJECTIVE: This study evaluated the long term outcomes of endovascular aneurysm repair using the Gore Excluder Low Permeability (LP) endoprosthesis across high volume Dutch hospitals. METHODS: A retrospective analysis was conducted of patients treated with the Excluder LP for infrarenal abdominal aortic aneurysm (AAA) in four hospitals between 2004 and 2017. Primary outcomes were overall survival, freedom from re-interventions (overall, inside and outside instructions for use, IFU), and AAA sac dynamics: growth (> 5 mm), stabilisation, and regression (< 5 mm). Secondary outcomes were technical success (device deployment), procedural parameters, and re-interventions. Follow up visits were extracted from patient files, with imaging assessed for complications and AAA diameter. RESULTS: Five hundred and fourteen patients were enrolled, with a median (IQR) follow up of 5.0 (2.9, 6.9) years. Survival rates were 94.0% at one year, 73.0% at five years, and 37.0% at 10 years, with freedom from re-interventions of 89.0%, 79.0%, and 71.0%, respectively. 37.9% were treated outside IFU, leading to significantly more re-interventions over 10 years compared with those treated inside IFU (36.0% vs. 25.0%, respectively; p = .044). The aneurysm sac regressed by 53.5% at one year, 65.8% at five years, and 77.8% at 10 years, and grew by 9.8%, 14.3%, and 22.2%, respectively. Patients with one year sac growth had significantly worse survival (p = .047). Seven patients (1.4%) had a ruptured aneurysm during follow up. Over 15 years, type 1a endoleak occurred in 5.3%, type 1b in 3.1%, type 3 in 1.9%, type 4 in 0.2%, and type 2 in 35.6% of patients. CONCLUSION: This multicentre study of real world endovascular aneurysm repair data using the Gore Excluder LP endoprosthesis demonstrated robust long term survival and re-intervention rates, despite 37.9% of patients being treated outside IFU, with type 4 endoleak being rare. Treatment outside IFU significantly increased re-intervention rates and one year sac growth was associated with statistically significantly worse survival.

Editor's Choice -- Age Stratified Midterm Survival Following Endovascular Versus Open Repair of Juxtarenal Abdominal Aortic Aneurysms.

OBJECTIVE: Age stratified mortality was examined following fenestrated endovascular aneurysm repair (F-EVAR) vs. open repair of juxtarenal abdominal aortic aneurysms (AAAs) METHODS: All patients undergoing first time elective F-EVAR and complex open aneurysm repair (c-OAR) for juxtarenal AAA in the Vascular Quality Initiative between 2014 and 2021 were identified. Open repairs were compared with commercially available fenestrated endovascular aneurysm repair and physician modified endografts (PMEGs). Patients were stratified into three age groups (< 65, 65 - 75, > 75 years). Primary outcomes were peri-operative and five year mortality, and inverse probability weighted risk adjustment was performed to account for baseline differences. RESULTS: Overall, 1 961 patients underwent F-EVAR (82% commercial F-EVAR, 18% PMEG) and 3 385 patients underwent c-OAR. Across age groups, the distribution of F-EVAR (vs. c-OAR) was: < 65 years: 23%, 65 - 75 years: 33%, > 75 years: 52%. After adjustment, among patients < 65 years, compared with c-OAR, F-EVAR was associated with similar peri-operative mortality (0.9% vs. 2.1%; hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.07 - 1.44], p = .22), and five year mortality (13% vs. 9.5%; HR 1.44, 95% CI 0.71 - 2.90, p = .31). Among patients aged 65 - 75 years, between juxtarenal AAA repair modalities, compared with c-OAR, F-EVAR was associated with a significantly lower risk of peri-operative mortality (2.2% vs. 5.0%; HR 0.50, 95% CI 0.30 - 0.79, p = .004), and five year mortality (13% vs. 13%; HR 0.94, 95% CI 0.65 - 1.36, p = .74). Similarly, among patients > 75 years, compared with c-OAR, F-EVAR was associated with lower peri-operative mortality (2.2% vs. 6.5%; HR 0.26, 95% CI 0.13 - 0.47, p < .001), but with similar five year mortality (18% vs. 21%; HR 0.83, 95% CI 0.57 - 1.20, p = .31). CONCLUSION: Among patients with a juxtarenal AAA, F-EVAR was associated with a lower peri-operative mortality compared with c-OAR in patients ≥ 65 years, but was similar in those < 65 years. At five years, F-EVAR was associated with similar mortality in all age groups, though there was a non-significant trend for a higher mortality rate in younger patients.

The Effect of One Year Aneurysm Sac Dynamics on Five Year Mortality and Continued Aneurysm Sac Evolution.

OBJECTIVE: One year aneurysm sac dynamics after endovascular abdominal aortic aneurysm repair (EVAR) were independently associated with a greater all cause mortality risk in prior registry studies but were limited in completeness and granularity. This retrospective analysis aimed to study the impact of sac dynamics on survival within the Endurant Stent Graft Global Registry (ENGAGE) with five year follow up. METHODS: A total of 1 263 subjects were enrolled in the ENGAGE Registry between March 2009 and April 2011. One year aneurysm sac changes were calculated between the one month post-operative imaging scans and the scan closest to the time of one year follow up. Sac regression was defined as a sac decrease of ≥ 5 mm and sac expansion as aneurysm sac growth ≥ 5 mm. The primary outcome was the five year all cause mortality rate. Kaplan-Meier estimates for freedom from all cause death were calculated. Multivariable Cox regression was used to determine the association between sac dynamics and all cause death. RESULTS: At one year, 441 of the 949 study participants with appropriate imaging (46%) had abdominal aortic aneurysm sac regression, 462 (49%) remained stable, and 46 (4.8%) had sac expansion. For patients with sac regression, the five year all cause mortality rate was 20%, compared with 28% for stable sac (p = .007) and 37% for the sac expansion (p = .010) cohorts. After adjustment, the sac expansion and stable sac cohorts were associated with a greater all cause mortality rate (expansion: hazard ratio [HR] 1.8; 95% CI 1.1 - 3.2; p = .032; stable: HR 1.4; 95% CI 1.1 - 1.9; p = .019). CONCLUSION: In the ENGAGE Global Registry, the one year rate of sac regression was 46%, and one year sac regression was observed to be associated with greater five year survival, corroborating prior findings using data from vascular registries. Sac regression could become the new standard for success after EVAR.

Midterm Outcomes and Aneurysm Sac Dynamics Following Fenestrated Endovascular Aneurysm Repair after Previous Endovascular Aneurysm Repair.

OBJECTIVE: Fenestrated endovascular aneurysm repair (FEVAR) is a feasible option for aortic repair after endovascular aneurysm repair (EVAR), due to improved peri-operative outcomes compared with open conversion. However, little is known regarding the durability of FEVAR as a treatment for failed EVAR. Since aneurysm sac evolution is an important marker for success after aneurysm repair, the aim of the study was to examine midterm outcomes and aneurysm sac dynamics of FEVAR after prior EVAR. METHODS: Patients undergoing FEVAR for complex abdominal aortic aneurysms from 2008 to 2021 at two hospitals in The Netherlands were included. Patients were categorised into primary FEVAR and FEVAR after EVAR. Outcomes included five year mortality rate, one year aneurysm sac dynamics (regression, stable, expansion), sac dynamics over time, and five year aortic related procedures. Analyses were done using Kaplan-Meier methods, multivariable Cox regression analysis, chi square tests, and linear mixed effect models. RESULTS: One hundred and ninety-six patients with FEVAR were identified, of whom 27% (n = 53) had had a prior EVAR. Patients with prior EVAR were significantly older (78 ± 6.7 years vs. 73 ± 5.9 years, p < .001). There were no significant differences in mortality rate. FEVAR after EVAR was associated with a higher risk of aortic related procedures within five years (hazard ratio [HR] 2.6; 95% confidence interval [CI] 1.1 - 6.5, p = .037). Sac dynamics were assessed in 154 patients with available imaging. Patients with a prior EVAR showed lower rates of sac regression and higher rates of sac expansion at one year compared with primary FEVAR (sac expansion 48%, n = 21/44, vs. 8%, n = 9/110, p < .001). Sac dynamics over time showed similar results, sac growth for FEVAR after EVAR, and sac shrinkage for primary FEVAR (p < .001). CONCLUSION: There were high rates of sac expansion and a need for more secondary procedures in FEVAR after EVAR than primary FEVAR patients, although this did not affect midterm survival. Future studies will have to assess whether FEVAR after EVAR is a valid intervention, and the underlying process that drives aneurysm sac growth following successful FEVAR after EVAR.

How We Would Treat Our Own Thoracoabdominal Aortic Aneurysm.

This manuscript is intended to provide a comprehensive review of the current state of knowledge on endovascular repair of thoracoabdominal aortic aneurysms (TAAAs). The management of these complex aneurysms requires an interdisciplinary and patient-specific approach in high-volume centers. An index case is used to discuss the diagnosis and treatment of a patient undergoing fenestrated-branched endovascular aneurysm repair for a TAAA.

Molecular phenotyping and functional assessment of smooth muscle-like cells with pathogenic variants in aneurysm genes ACTA2, MYH11, SMAD3 and FBN1.

Aortic aneurysms (AAs) are pathological dilatations of the aorta. Pathogenic variants in genes encoding for proteins of the contractile machinery of vascular smooth muscle cells (VSMCs), genes encoding proteins of the transforming growth factor beta signaling pathway and extracellular matrix (ECM) homeostasis play a role in the weakening of the aortic wall. These variants affect the functioning of VSMC, the predominant cell type in the aorta. Many variants have unknown clinical significance, with unknown consequences on VSMC function and AA development. Our goal was to develop functional assays that show the effects of pathogenic variants in aneurysm-related genes. We used a previously developed fibroblast transdifferentiation protocol to induce VSMC-like cells, which are used for all assays. We compared transdifferentiated VSMC-like cells of patients with a pathogenic variant in genes encoding for components of VSMC contraction (ACTA2, MYH11), transforming growth factor beta (TGFß) signaling (SMAD3) and a dominant negative (DN) and two haploinsufficient variants in the ECM elastic laminae (FBN1) to those of healthy controls. The transdifferentiation efficiency, structural integrity of the cytoskeleton, TGFß signaling profile, migration velocity and maximum contraction were measured. Transdifferentiation efficiency was strongly reduced in SMAD3 and FBN1 DN patients. ACTA2 and FBN1 DN cells showed a decrease in SMAD2 phosphorylation. Migration velocity was impaired for ACTA2 and MYH11 cells. ACTA2 cells showed reduced contractility. In conclusion, these assays for showing effects of pathogenic variants may be promising tools to help reclassification of variants of unknown clinical significance in AA-related genes.

Sex-related Outcomes after Thoracic Endovascular Repair for intact isolated Descending Thoracic Aortic Aneurysm: A Retrospective Cohort Study.

OBJECTIVE: To evaluate the association between sex and outcomes following TEVAR for intact isolated descending thoracic aortic aneurysms (iiDTAA). SUMMARY BACKGROUND DATA: Data regarding sex-related long-term outcomes after TEVAR for iiDTAA are limited and conflicting results regarding perioperative outcomes have been reported. METHODS: We included all TEVAR for iiDTAA between 2014-2019 in the Vascular Quality Initiative linked to Medicare claims, allowing reliable assessment of long-term outcome data. Primary outcomes included 5-year mortality, reinterventions, and ruptures of the thoracic aorta. Secondarily we assessed perioperative outcomes. RESULTS: We identified 685 patients, of which 54% were females. Females had higher aortic size index (females vs. males: 3.31 [IQR, 2.81-3.85] cm/m2 vs. 2.93 [IQR, 2.42-3.36] cm/m2; P<.001), were more frequently symptomatic (31% vs. 20%; P=.001), had longer procedure time (111 [IQR, 72-165] min vs. 97 [IQR, 70-146] min) and more iliac procedures (16% vs. 7.6%; P=.001). Compared with males, females had similar rates of 5-year mortality (58% vs. 53%; HR, 0.93; 95%CI 0.71-1.22; P=.61), reinterventions (39% vs. 30%; HR, 1.12; 95%CI 0.73-1.73; P=.60) and late ruptures (0.6% vs. 1.2%; HR, 0.87; 95%CI 0.12-6.18; P=.89). After adjustment, these outcomes remained similar through 5-years. Furthermore, perioperative mortality was not significantly different between sexes (4.1% vs. 2.2%; P=.25), as were rates of any complication as a composite outcome (16% vs. 21%; P=.16), as well as of individual complications (all P>.05). CONCLUSIONS: Our findings suggest that females who undergo TEVAR for iiDTAA have similar 5-year and perioperative outcomes as compared with males.