Transrectal Hybrid Natural Orifice Transluminal Endoscopic Surgery (NOTES) Nephrectomy in a Porcine Model

Wassim M. Bazzia, Oliver Wagnerb, Sean P. Stroupa, Jonathan L. Silbersteina, Noam Belkindb, Toshio Katagirib, Julieta Palearib, Agustin Durob, Sonia Ramamoorthyb, c, Mark A. Talaminib, c, Santiago Horganb, c and Ithaar H. Derweesha, Corresponding Author Contact Information, E-mail The Corresponding Author

a Department of Surgery, Division of Urology, University of California, San Diego School of Medicine, La Jolla, CA

b Department of Surgery, Division of Minimally Invasive Surgery, University of California, San Diego School of Medicine, La Jolla, CA

c Center for the Future of Surgery, University of California, San Diego School of Medicine, La Jolla, CA

Objective

To examine feasibility of transrectal hybrid natural orifice translumenal endoscopic surgery (NOTES) nephrectomy in the porcine model. NOTES uses ports of entry to the peritoneal cavity instead of abdominal wall incisions, thereby eliminating visible scar and also potentially reducing postoperative pain.

Methods

After obtaining Institutional Animal Care and Use Committee approval, 3 female pigs (45 kg) underwent transrectal hybrid NOTES nephrectomy (2 right, 1 left). Pneumoperitoneum was created by a periumbilically-inserted 12-mm trocar, through which a laparoscope was advanced to obtain intraabdominal visualization. A horizontal incision was made 2 cm above the dentate line and a submucosal tunnel was created in the posterior rectal wall/presacral space. A dual-channel gastroscope was advanced through the submucosal tunnel and retroperitoneum to the level of the kidney using air insufflation. A window in the peritoneum was created and renal mobilization was completed. A transumbilically applied laparoscopic 45-mm stapler was used to transect the ureter and renal hilum. A specimen extraction bag was deployed transrectally and the specimen was delivered intact, followed by transrectal incision closure.

Results

Transrectal hybrid NOTES nephrectomy was successfully performed in all cases. Mean operative time was 180 minutes (30 minutes for rectal access). Estimated blood loss was 50 mL. On necropsy, no intraabdominal injuries were noted.

Conclusions

In this initial report on feasibility of transrectal hybrid NOTES nephrectomy, we were able to perform the procedures with minimal blood loss and extract intact specimen. Survival studies are prerequisite to assess sterility and short- and long-term complications. This approach may be useful as an alternative to transvaginal access.