Long-term decline in renal function is more significant after endovascular repair of infrarenal abdominal aortic aneurysms
Al Adas Z, Shepard AD, Nypaver T, Weaver MR, Maatman T, Yessayan L, and Kabbani L. Long-term decline in renal function is more significant after endovascular repair of infrarenal abdominal aortic aneurysms. J Vasc Surg 2017; 65(6):28S-29S.
J Vasc Surg
Objectives: It is not clear whether endovascular repair of abdominal aortic aneurysms (EVAR) Results in more decline in renal function over the long-term when compared to open repair (OR). We reviewed our experience with abdominal aortic aneurysm (AAA) repair to determine whether there was a significant difference in immediate postoperative and long-term renal outcomes between OR and EVAR. Methods: A retrospective cohort study was conducted on all patients who underwent AAA repair between January 1993 and July 2013 at a tertiary referral hospital. Demographics, comorbidities, preoperative and postoperative laboratory values, morbidity, and mortality were collected. Patients with ruptured AAAs, preoperative hemodialysis, juxtarenal or suprarenal aneurysm origin, and no follow-up laboratory values were excluded. Preoperative, postoperative, 6-month, and yearly serum creatinine values were collected. Glomerular filtration rate (GFR) was calculated based on the Chronic Kidney Disease Epidemiology Collaboration equation. Acute kidney injury (AKI) was classified using the Kidney Disease: Improving Global Outcomes guidelines. Δ GFR was defined as preoperative GFR minus the GFR at each follow-up interval. Comparison was made between EVAR and OR groups using multivariate logistics for categoric data and linear regression for continuous variables. Results: During the study period, 769 infrarenal AAA repairs were performed at our institution; 675 repairs fit the inclusion criteria (315 OR and 360 EVARs). Mean age was 73.9 years, 79% were males, 78% were hypertensive, 18% were diabetic, and 31% had preoperative renal dysfunction defined as a GFR <60 mL/min. A multivariate logistic model to control for all variables found that OR had a 1.6-times greater chance of developing immediate postoperative AKI compared with EVAR (P =.038). Hypertension and aneurysm size were also independent risk factors for developing AKI (P =.012 and P =.022, respectively). Using a linear regression model, we found a greater decline in GFR postoperatively in the EVAR group. This was significant starting at postoperative year 4 (Fig). AKI and preoperative renal dysfunction were other independent risk factors for long-term decline in renal function. Conclusions: Despite the deleterious effect of OR on immediate postoperative renal function, patients undergoing OR experience a slower decline in GFR over time compared to EVAR patients. The basis for this greater decline in renal function in EVAR patients is undefined but could relate to the need for postoperative EVAR surveillance. Studies comparing EVAR and OR may need longer follow-up to detect clinically significant differences in renal function.