Laparoscopic aortorenal bypass

Open surgical renovascular repair, although producing excellent results, confers significant operative morbidity. As a result, less morbid procedures such as percutaneous balloon angioplasty and stenting have gained increasing acceptance. Laparoscopic techniques have not previously been applied to renal revascularization. The aim of this study was to demonstrate the technical feasibility and the long-term clinical and pathologic outcomes of laparoscopic aorto-left renal artery bypass in a chronic porcine model.

Eight animals were used in the study. All laparoscopic suturing and knot-tying were performed intracorporeally using free-hand techniques. The following operative steps were employed: (1) aortic dissection and cross-clamping; (2) transection and refashioning of the left renal artery ostium; (3) in-situ renal hypothermia; (4) end-to-side aorto-left renal artery anastomosis; and (5) aortic unclamping. In situ renal hypothermia was achieved laparoscopically by infusion of ice-cold heparinized saline into the renal artery through a balloon catheter.

All eight pigs underwent laparoscopic aortorenal bypass successfully. The median surgical time was 110 minutes, and the aortic cross-clamping time was 45.5 minutes. The median anastomotic time was 40 minutes, and the renal warm ischemia time was 9 minutes. The median estimated blood loss was 30 mL. An intraoperative complication of suture breakage leading to anastomotic hemorrhage occurred in one animal; the problem was corrected laparoscopically. Postoperatively, one animal died from pneumonia. The remaining seven animals experienced no postoperative complications and were euthanized, one each at postoperative day 0 and 1 and week 1, 2, 3, 4, and 6. The median preoperative and postoperative (at euthanasia) serum creatinine values (1.15 mg/dL v 1.2 mg/dL; P = 0.39) were similar. However, compared with preoperative peripheral renin activity (0.25 microg/L per hour), the postoperative peripheral renin activity was elevated (0.9 microg/L per hour; P = 0.047). Autopsy revealed a grossly normal left kidney, with Doppler confirmation of flow in the repaired renal artery in all seven animals. Ex vivo angiography confirmed a patent anastomosis. On histopathology examination, the early left renal parenchymal specimens revealed transient, mild acute tubular necrosis that resolved over sequential specimens without significant long-term sequelae. Histologic analysis of the aorto-left renal artery anastomotic site revealed gradual endothelialization with time.

Laparoscopic aortorenal artery revascularization is technically feasible. Our chronic animal model has demonstrated durable success over a 6-week follow-up. This study represents the initial report in the literature.