Retroperitoneal minilaparoscopic nephrectomy in the rat model

Objectives. Development of small animal models for laparoscopic surgery is important for basic pathophysiologic and oncologic studies, instrument deve lopment, and surgical training. Although transperitoneal laparoscopy has be en described in the rat, the technical feasibility of the retroperitoneosco pic approach for major renal surgery has not been reported previously. Here in, we describe the development of a rat model for retroperitoneal minilapa roscopic nephrectomy, Methods. Sixteen male Sprague-Dawley rats underwent a three-port bilateral retroperitoneoscopic nephrectomy using 2 and 3-mm instruments and optics ex clusively. After developing the technique in 10 animals, the study was cond ucted in 6 animals. Following retroperitoneal balloon dilation and CO2 pneu moretroperitoneum (mean 4.5 mm Hg), nephrectomy was accomplished by intraco rporeal en bloc ligation of the renal pedicle. To prevent peritoneal entry, the anterior surface of the kidney was mobilized subcapsularly. Volume of the created retroperitoneal space and peritoneal integrity were confirmed b y a contrast x-ray study. Intraperitoneal pressure was monitored constantly during the procedure. Results. Mean surgical time was 74.5 minutes (range 60 to 95) and estimated blood loss was less than 1 mL. Mean volume of the retroperitoneal space wa s 8.4 mL after initial balloon dilation, and 11.5 mL after nephrectomy. Mea n weight of the excised kidneys was 1.4 g. Inadvertent peritoneotomy occurr ed during 3 of 1 2 study nephrectomies. Complications included renal artery hemorrhage leading to death in 1 animal and renal vein injury in 1 animal. Conclusions. Laparoscopic retroperitoneal nephrectomy in the rat model is t echnically feasible. This novel small animal model can be used for further studies of the retroperitoneal laparoscopic approach. UROLOGY 56: 1058-1062 , 2000. (C) 2000, Elsevier Science Inc.