The Impact of Suprarenal Cross-Clamping on Kidney Function in Patients Undergoing Retroperitoneal Abdominal Aortic Aneurysm Repair following an Enhanced Recovery Protocol

Background: The retroperitoneal approach (RP) is a well-established procedure for juxtarenal and infrarenal (IR) abdominal aortic aneurysm (AAA) repair when an endovascular option is not available. The aim of this study is to compare the effect of suprarenal (SR) and IR aortic clamping on postoperative renal function following an Enhanced Recovery Protocol (ERP). Since there are no defined guidelines within aortic surgery, we focused our attention on the role of fluid and vasopressor administration in the development of postoperative acute kidney injury (AKI). Methods: This is a single-center retrospective cohort study on 140 RP aortic aneurysm repair patients operated between 2009 and 2019. Patients were divided in 2 groups: 24 had SR clamping and 116 IR clamping. Since 2009, at our institution all patients have followed an Enchanced Recovery Program which has been implemented as standard care for patients undergoing open AAA repair. Results: The 2 groups were well matched for baseline characteristics, preoperative renal function, and comorbidity. There was an increased need for intraoperative fluids (P = 0.015), and vasopressors (P = 0.002) in the SR group compared to the IR group. Patients in the SR group showed a higher trend of postoperative AKI as opposed to the control group (37.5% vs. 19.8%), although this event was not statistically significant (P = 0.106). Acute Kidney Injury Network stage III requiring temporary dialysis occurred in only 3 patients who all belonged to the IR group. Conversely, stage I and II with a 2- or 3-fold increase in postoperative creatinine were more frequent in the SR group. However, these normalized before discharge in all cases. To the best of our knowledge, none of the above required permanent dialysis. Conclusions: The results from this study show that SR clamping during RP juxtarenal aortic aneurysm repair does not have an adverse effect on postoperative renal function in the short term. However, patients undergoing SR clamping require greater fluid and vasopressor usage, in contrast with the restrictive fluid therapy established by traditional protocols. This could be an important benchmark for future implementation of ERPs in vascular surgery, especially in open procedures requiring visceral clamping.