Outcomes after endovascular aneurysm repair conversion and primary aortic repair for urgent and emergency indications in the Society for Vascular Surgery Vascular Quality Initiative

Abstract

Objective: Open conversion after endovascular aortic aneurysm repair (EVAR-c) is performed nonelectively in up to 60% of cases. EVAR-c has been reported to have significantly greater risk of postoperative morbidity and mortality than primary aortic repair, but few data exist on outcomes for symptomatic or ruptured presentations. This study determined outcomes and identified predictors of postoperative major adverse cardiac events (MACEs) and mortality for patients undergoing nonelective EVAR-c compared with nonelective primary aortic repair (PAR) in the Vascular Quality Initiative (VQI).

Methods: All VQI patients undergoing urgent/emergency EVAR-c or urgent/emergency PAR from 2002 to 2014 were reviewed. Urgent presentation was defined by repair ≤24 hours of a nonelective admission, and emergency operations had clinical or radiographic evidence, or both, of rupture. End points included in-hospital MACE (myocardial infarction, dysrhythmia, congestive heart failure) and 30-day mortality. Possible covariates identified on univariate analysis (P < .2) were entered into a multivariable model, and stepwise elimination identified the best subset of predictors. Generalized estimating equations logistic regression analysis was used to determine the relative effect of EVAR-c compared with PAR on outcomes.

Results: During the study interval, we identified 277 EVAR-c, and 118 (43%) underwent urgent/emergency repair. nonelective PAR was performed in 1388 of 6152 total (23%). EVAR-c patients were older (75 ± 9 vs 71 ± 10 years; P < .0001), more likely to be male (84% vs 74%; P = .02), and had a higher prevalence of hypertension (88% vs 79%; P = .02) and coronary artery disease (38% vs 27%; P = .01). No differences in MACE (EVAR-c, 31% [n = 34] vs PAR, 30% [n = 398]) or any major postoperative complication (EVAR-c, 57% [n = 63] vs PAR, 55% [n = 740]; P = .8) were found; however, 30-day mortality was significantly greater in EVAR-c (37% [n = 41]) than in (PAR, 24% [n = 291]; P = .003), with an odds ratio (OR) of 2.2 (95% confidence interval [CI], 1.04-4.77; P = .04) for EVAR-c. Predictors of any MACE included age (OR, × 1.03 for each additional year; 95% CI, 1.01-1.03; P = .0002), male gender (OR, 1.3; 95% CI, 1.03-1.67; P = .03), body mass index ≤20 kg/m² (OR, 1.8; 95% CI, 1.13-2.87; P = .01), chronic obstructive pulmonary disease (OR, 1.2; 95% CI, 0.86-1.80; P = .25), congestive heart failure (OR, 1.5; 95% CI, 0.98-2.34; P = .06), preoperative chronic β-blocker use (OR, 1.3; 95% CI, 0.97-1.63; P = .09), and emergency presentation (OR, 2.3; 95% CI, 1.8-3.01; area under the curve, 0.70; P < .0001). Significant predictors for 30-day mortality were age (OR × 1.07 for each additional year; 95% CI, 1.05-1.09; P < .0001), female gender (OR, 1.6; 95% CI, 1.01-2.46; P = .04), preoperative creatinine >1.8 mg/dL (OR, 1.6; 95% CI, 1.04-2.35; P = .03), an emergency presentation (OR, 4.8; 95% CI, 2.93-7.93; P < .0001), and renal/visceral ischemia (OR, × 1.1 for each unit increase log (time-minutes); 95% CI, 1.02-1.22; area under the curve, 0.84; P = .01).

Conclusions: Nonelective EVAR-c patients are older and have higher prevalence of cardiovascular risk factors than PAR patients. Similar rates of postoperative complications occur; however, urgent/emergency EVAR-c has a significantly higher risk of 30-day mortality than nonelective PAR. Several variables are identified that predict outcomes after these repairs and may help risk stratify patients to further inform clinical decision making when patients present nonelectively with EVAR failure.

Fig. 1

This flow chart shows the different inclusion and exclusion groups in the analysis. Of all native abdominal aortic aneurysm (AAA) repairs in the Vascular Quality Initiative (VQI), 32% were nonelective. There were 277 endovascular aneurysm repair (EVAR) conversion (EVAR-c) procedures (6% of total infrarenal aortic operations). Estimating the true incidence of EVAR-c from the VQI is not possible because patients undergoing an index EVAR at a VQI institution can undergo EVAR-c at non-VQI facilities. The mode of presentation for nonelective primary aortic repair and nonelective EVAR-c was similar (~60% for a ruptured indication).

Fig. 2

This bar graph highlights the expected differences that symptomatic and ruptured presentations have on 30-day postoperative mortality. Not surprisingly, a ruptured presentation for native abdominal aortic aneurysm (AAA) and endovascular aneurysm repair conversion (EVAR-c) patients had significantly worse outcome. Interestingly, EVAR-c was not associated with higher rates of postoperative complications; however, mortality was significantly different. EVAR-c patients undergoing nonelective repair had significantly greater risk of 30-day mortality compared with nonelective primary aortic repair (PAR) irrespective of presenting with a symptomatic or ruptured indication.

Fig. 3

The additive risk that endovascular aneurysm repair conversion (EVAR-c) has to nonelective abdominal aortic aneurysm (AAA) repair is highlighted. Similar risk profiles are compared among hypothetical nonelective infrarenal aortic aneurysm repair patients, with or without endograft explantation. Various random combinations of different 30-day mortality risk factors (Table IV) are depicted. The 30-day mortality risk is twofold greater for nonelective patients undergoing EVAR-c compared with native AAA repair. Ant, Antegrade; BB, β-blockers; CRI, chronic renal insufficiency; F, female; M, male; PAR, primary aortic repair.

Fig. 4

A, The two survival curves highlight the overall survival comparison between nonelective endovascular aneurysm repair conversion (EVAR-c) and primary aortic repair (PAR) patients in the Vascular Quality Initiative (VQI). PAR patients have a significant survival advantage that is maintained out to at least 3 years (log-rank P = .0006). All displayed intervals have <10% standard error of the mean. B, The significant differences in survival among the different modes of presentation are demonstrated. Specifically, patients undergoing symptomatic or ruptured aortic repair with or without need for EVAR-c are compared. Among all intergroup comparisons, EVAR-c confers a significantly higher risk of all-cause mortality compared with PAR patients. Notably, EVAR-c patients are frequently older and have an increased incidence of cardiovascular risk factors that affect long-term survival. All displayed intervals have <10% standard error of the mean.