Gasless vaginal natural orifice transluminal endoscopic surgery(vNOTES): a safe and feasible approach for adnexal procedures

Vaginal natural orifice transluminal endoscopic surgery (vNOTES) is an important technique in minimally invasive gynecology. However, conventional vNOTES relies on CO₂ pneumoperitoneum, which may lead to complications such as postoperative pain and hypercapnia. Gasless vNOTES has been proposed as an alternative, but existing techniques often require additional abdominal wall lifting devices that increase procedural complexity and trauma. This study aimed to assess the feasibility and safety of gasless vaginal natural orifice transluminal endoscopic surgery (vNOTES) without abdominal wall retractors in benign adnexal surgery. This retrospective case series included patients who underwent benign adnexal surgery with gasless vNOTES between September 2024 and August 2025 at the International Peace Maternity and Child Health Hospital in Shanghai. Data were collected on baseline characteristics and surgical outcomes were collected, including history of abdominal surgery, pathological types of adnexal masses, surgical procedures, operative time, volume of intraoperative blood loss, complications, postoperative pain scores using the Visual Analog Scale (VAS), time to first flatus, and length of postoperative hospital stay. A total of 373 patients who underwent vNOTES for benign adnexal disease were included in the study. Overall, 370 (99.2%) patients successfully underwent gasless vNOTES, while one case required conversion to gas‑based vNOTES and two cases required conversion to transumbilical laparoendoscopic single-site surgery (TU-LESS) due to pelvic adhesions (conversion rate, 0.8%). In five cases (1.4%), in which the ovarian cyst was located anterior to the uterus and difficult to expose, brief pneumoperitoneum (< 5 min) was applied to retract the mass posterior to the uterus, after which gasless vNOTES was resumed following desufflation. Surgical procedures included ovarian cystectomy (314 cases, 84.9%), surgery for ectopic pregnancies (11 ruptured and 28 unruptured cases, 10.5%), and adnexectomy (10 cases, 2.7%). The mean operative time was 54.41 ± 25.94 min, and mean intraoperative blood loss was 25.63 ± 14.31 mL. No intraoperative complications, such as visceral injury or major hemorrhage, occurred. The median postoperative VAS pain scores were 1.0 (0, 2.0) at 6 h and 0 (0, 1.0) at 12 h. The mean time to first flatus was 7.12 ± 4.51 h, and the mean postoperative hospital stay was 22.09 ± 10.36 h. The postoperative infection rate was 1.9%, and all cases were managed successfully using antibiotics. Gasless vNOTES is a safe and feasible technique for benign adnexal surgery. In this series, 99.2% of procedures were completed without conversion. The findings suggest that this approach is technically straightforward and associated with short operative time, low postoperative pain, and rapid recovery. Gasless vNOTES may be a promising alternative to traditional gas-based vNOTES and warrants further prospective evaluation. ChiCTR2600119572.