The Effect of Left Renal Vein Division on Renal Function Following Open Abdominal Aortic Surgery Using Propensity Score Matching Analysis

Abstract

Open surgery of abdominal aortic aneurysm (AAA) or aortoiliac occlusive disease (AIOD) sometimes requires left renal vein division (LRVD) to gain adequate exposure of the abdominal aorta. The aim of this study is to evaluate the effect of LRVD on the postoperative renal function using propensity score matching (PSM). From July 1996 to January 2018, we retrospectively reviewed 698 patients who underwent open aortic surgery, including 543 AAAs and 155 AIODs, at a single institution. 66 patients (9.6%, 47 AAAs, 19 AIODs) needed LRVD during the operation. A 1:3 ratio PSM was used to control the selective bias between the LRVD and non-LRVD groups. We investigated preoperative and postoperative renal function including serum creatinine (sCr) level and estimated glomerular filtration rate (eGFR, mL/min/1.73m2). Major complications, long-term renal function, and 30-day mortality were also compared. The LRVD group had a significantly higher rate of renal artery reconstruction (15.2% vs. 3.3%, P<0.001) and suprarenal clamping (54.6% vs. 9.5%, P<0.001) and higher incidence of juxtarenal AIOD (24.2% vs. 5.4%, P<0.001). With PSM, 63 patients in the LRVD group and 144 patients in the non-LRVD group were enrolled in this study. The baseline characteristics were well balanced in the groups after PSM. There were no significant differences in preoperative eGFR (72.4±21.3 vs. 76.1±25.0, P=0.306) and postoperative eGFR on day 3 (69.5±26.6 vs. 77.5±28.5, P=0.065), day 7 (73.3±24.8 vs. 78.5±27.4, P=0.264), and in the long-term follow-up period (69.0±22.2 vs. 68.9±27.1, P=0.986, 50.2month±45.50) in the 2 groups. Only the sCr level (1.40±0.59 vs. 1.21±0.62, P=0.045) and eGFR (59.5±23.9 vs. 71.4±26.0, P=0.002) were significantly worse on postoperative day 1 in the LRVD than in the non-LRVD group. There were no significant differences in 30-day mortality (1.6% vs. 1.6%, P=1.00). The patients in the LVRD group underwent initial drop in renal function; however, eGFR improved during the follow-up period. There was no difference in renal function and postoperative mortality between LRVD and non-LRVD groups. Therefore, LRVD is a safe and durable procedure during complex abdominal aortic surgery.