Outcomes after Elective Abdominal Aortic Aneurysm Repair Have Improved Over Time in Patients on Dialysis.

backgroundPrior studies have demonstrated poor perioperative and long-term survival of patients with end-stage kidney disease (ESKD) on dialysis who undergo abdominal aortic aneurysm repair (AAAR). However, survival in dialysis patients overall has improved over time. We hypothesize that the contemporary rates of perioperative and long-term survival following AAAR in ESKD patients are also improving.

methodsData on AAAR procedures in dialysis patients were collected from the United States Renal Data System between 2008 and 2017. Endovascular (EVAR) and open AAA repair (OAR) were identified by Current Procedural Terminology codes. Patients with a functioning renal transplant, a ruptured aneurysm, and insurance other than Medicare were excluded. Demographics, comorbidities, procedural details, and long-term outcomes were collected. Standard statistical methods were used.

resultsWe identified 3,374 patients who underwent EVAR (86%, 2,914/3,374) and OAR (14%, 460/3,374). The utilization of OAR decreased significantly from 2008 to 2017 (17.34% vs. 7.43%, P < 0.001). Kaplan-Meier survival analysis revealed no significant difference in 5-year survival between OAR and EVAR (24% vs. 17%, P = 0.1, Wilcoxon-Breslow test), but open repair was associated with increased long-term survival (Hazards ratio 0.994, confidence interval 0.990-0.999, P = 0.017) in an adjusted Cox regression model. The cohort was then divided based on the year of AAAR, group 1: 2008-2010 (1,269/3,374), group 2: 2011-2013 (1,071/3,374), and group 3: 2014-2017 (1,034/3,374). Compared to groups 1 and 2, Group 3 was less likely to have coronary artery device, peripheral vascular disease, recent pneumonia, be nonambulatory, live in a nursing facility, or undergo an OAR and more likely to be younger and dialyze through an arteriovenous fistula/arteriovenous graft at the time of AAA repair. Thirty-day postoperative mortality was significantly lower in group 3 compared to groups 1 and 2 (5.4% [56/1,034] vs. 10.3% [131/1,269]/7.3% [78/1,071], P < 0.031). One-year survival by Kaplan-Meier estimate was significantly higher in group 3 (77.7% [803/1,034]) versus groups 1 and 2 (56.7% [719/1,269], 66.9% [716/1,071], P < 0.001, log-rank test). Five-year survival was also significantly higher in group 3 (27.3%) compared to groups 1 and 2 (14.2% and 16.5%, P < 0.001, log-rank test). In a Cox regression model of long-term mortality adjusted for variables significant on a univariate testing, more recent procedure year was associated with increased survival (Hazards ratio 0.81, [0.77, 0.85], P < 0.001).

conclusionsPostoperative and long-term survival following AAA repair have increased over time in ESKD patients on dialysis. This increased survival persists after accounting for differences in patient demographics and type of procedure over time. Elective AAA repair should be considered in carefully selected good-risk patients on dialysis.