Comparison of Transrectal and Transvaginal Hybrid Natural Orifice Transluminal Endoscopic Surgery Partial Nephrectomy in the Porcine Model

Abstract

To compare the feasibility of porcine transrectal (TR) and transvaginal (TV) hybrid natural orifice transluminal endoscopic surgery (NOTES) partial nephrectomy (PN), as NOTES nephrectomy has recently been performed in the porcine model. A total of 10 female pigs (weight 45 kg) underwent TR (n= 5) or TV (n= 5) NOTES PN. The pneumoperitoneum was created by a periumbilical 12-mm trocar, through which a laparoscope was advanced for intra-abdominal visualization. For TV-NOTES PN, a gastroscope was used to obtain TV peritoneal access. For TR-NOTES PN, a horizontal incision was made 2 cm above the dentate line, and a submucosal tunnel was created in the posterior rectal wall. The gastroscope was advanced through the submucosal tunnel and retroperitoneum to the kidney, and a peritoneal window was created. For both TR- and TV-NOTES PN, the gastroscope was exchanged for the SPIDER Surgical System. Flexible dissecting instruments and hook cautery introduced through the SPIDER Surgical System were used to mobilize the kidney. A harmonic scalpel introduced periumbilically was used to excise a portion of the lower pole. LAPRA-TY-secured sutured renorrhaphy was performed, followed by TR or TV specimen extraction. TR- and TV-NOTES PN was successfully performed in all 10 pigs. A comparison of TR- and TV-NOTES PN revealed no significant differences in the mean access time (29.2 vs 29.6 minutes, P= .944), operative time (196.0 vs 183.0 minutes, P= .631), and estimated blood loss (59.0 vs 54.0 mL, P= .861). Necropsy did not demonstrate abdominal injuries. We have demonstrated proof-of-principle for TR and TV-NOTES PN in swine, with comparable perioperative parameters. Preclinical survival studies are requisite to assess the potential of TR-NOTES as an alternative to TV-NOTES.