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OBJECTIVE - AAA repair in the general population is effective, with reported mortality rates of <10% at one year. The outcomes of AAA repair in patients on dialysis are not well characterized, with a questionable survival advantage in such patients with limited life expectancy. The purpose of this paper is to study the outcomes of AAA repair in US dialysis patients.

METHODS - The United States Renal Data System (USRDS) was used to collect data on intact asymptomatic AAA repair in all dialysis patients in the USA from the 2005-2008 Physician-Services data files. Elective EVAR and open repair were identified by CPT codes. Primary outcomes were the peri-operative (30-day) mortality and long term survival. Bivariate associations were tested using the chi-squared test, and predictors of mortality were identified using regression models.

RESULTS - Out of 2,260,986 dialysis patients, 1557 age 30 and older had an AAA repair (0.05%): 261 open and 1296 EVAR (Table 1). The 30-day mortality was 11.5% (10.5% EVAR, 16.22% open repair, p=0.009). The mortality rate 1 year after AAA repair was 39.0% (39.3% EVAR, 37.7% open repair, p=0.65). Kaplan Meier estimates of survival were 66.5% at 1 year (66.2% EVAR, 67.5% Open, p=0.78), and only 37.4% at 3 years (36.8% EVAR, 39.8% Open, p=0.65). Women had a higher overall mortality rate at 1 year (43.1%) compared to males (37.4%) (p=0.06). There was no significant 1 year mortality difference when comparing type of procedure in males (EVAR= 37.4%, Open= 37.6%, p=0.95) and in females (EVAR= 44.4%, Open= 37.7%, p=0.31). By logistic regression, older age (years, OR=1.03; 95% CI: 1.02-1.05; p<0.001), less time on dialysis (months, OR=0.99; 95%CI: 0.981-1.00 ; p<0.001), absence of a transplant (OR transplant= 0.30; 95%CI: 0.20-0.45 ; p<0.001); diabetes (OR=1.75, 95%CI: 1.18- 2.60, p=0.006), absence of hypertension (OR hypertension=0.54; 95%CI: 0.34-0.85 ; p=0.008), and BMI (OR=0.96, 95%CI: 0.93-0.98, p=0.002) had significant associations with mortality within the observation period.

CONCLUSIONS - AAA patients on dialysis have a high peri-operative and 1 year mortality rates following EVAR or open repair. This questions the indications for intact AAA repair in dialysis patients, especially in diabetics, women, or older patients. AAA repair in dialysis patients may have to be restricted to patients with larger aneurysms especially if open repair is required.
Table 1