Hydrogen leak test is minimally invasive and highly specific for assessment of the integrity of the luminal closure after natural orifice transluminal endoscopic surgery procedures (with video)

摘要

Background: Leak-resistant closure of transluminai access is a major challenge facing natural orifice transluminal endoscopic surgery (NOTES).Objective: To evaluate a hydrogen (H_2)-based leak test for assessment of transluminal-access closure integrity after NOTES procedures.Setting: Nine acute porcine experiments.Design and Intervention: After gastric-wall puncture and balloon dilation, peritoneoscopy was performed, followed by transmural closure of the gastric opening. The animals were randomly assigned to complete or incomplete closure groups. The H_2 leak test was performed by using 1000 mL of 4% H_2 gas mixture and the Hydrogen Leak Detector H_2000+. The animals were then euthanized for a methylene blue (MB) test of gastric closure integrity.Main Outcome Measurement: Intraperitoneal H_2 concentration after gastric insufflation with H_2.Results: The H_2 leak test was quick and easy. Intraperitoneal H_2 concentrations in parts per million in both groups were similar at baseline (mean +- SD, 0.18 +- 0.29 parts per million [ppm] vs 0.22 +- 0.35 ppm, P = .97) and after balloon dilation (414.8 +- 198.5 ppm vs 601.3 +- 116.1 ppm, P > .99). Postclosure intraperitoneal H_2 concentrations dropped to 0.01 +- 0.77 ppm in the complete-closure group, similar (P = .81) to matched-pairs preopening levels and significantly lower than in the incomplete-closure group (162.0 +- 83-0 ppm, P < .02). On necropsy, the MB test was negative in all 5 animals of the complete-closure group and positive in all 4 animals of the incomplete-closure group. A cutoff of 25 ppm in intraperitoneal H_2 concentration after closure gave 100% sensitivity, specificity, and positive and negative predictive values for MB leakage.Limitations: Nonsurvival animal experiments.Conclusions: The H_2 leak test is highly accurate for detection of leakage after NOTES procedures and could become a substitute for currently used MB leak tests.