Pure transvesical NOTES uterine horn resection in swine as an appendectomy model

Because of size limitation, the lack of reliable instruments, and bladder closure methods, transvesical natural orifice translumenal endoscopic surgery (NOTES) is still in its infancy. The porcine uterine horn is similar to the human vermiform appendix. Therefore, the resection of the porcine uterine horn is an established animal model for the human appendectomy. In this study, we evaluated the feasibility of a pure transvesical NOTES approach to uterine horn resection in a porcine model.

We performed five operations on three female pigs (30-35 kg) under general anesthesia in the Trendelenburg position. The laparoscope at the umbilicus was used only for the purpose of documentation. We used a rigid ureteroscope and a customized access system that prevented gas leakage and facilitated in-and-out passage of the instruments. A vesicostomy was created on the posterolateral bladder wall by using a needle knife through the channel of the ureteroscope. The uterine horn resection was performed by using an electric needle knife, hot forceps, and a polypectomy snare through the access system placed in vesicostomy. Bladder closure was performed with extracorporeal ties using metal clip tagged threads and a knot-pusher.

We successfully performed the pure transvesical NOTES uterine horn resections. The mean total operative time was 141.8 (± 58.7) min, and blood loss was minimal in all cases. No leakage was observed at the bladder repair sites after filling with normal saline. The removed uterine horns were approximately 6-12-cm long and 0.6-0.8 cm in diameter. On final inspection, the urethras were not damaged.

This study demonstrates the feasibility of a pure transvesical NOTES uterine horn resection in a porcine model. To the best of our knowledge, this is the world's first report on a pure transvesical NOTES with a therapeutic purpose. This study shows the potential for adoption of the transvesical approach in NOTES procedures.