Characterisation and mitigation of gas leaks at laparoscopy: an international prospective, multi-center cohort clinical trial.

INTRODUCTION: Gas leaks polluting the operating room are common in laparoscopy. Studies defining methods for sensitive leak characterisation and mechanical mitigation in real world settings are, however, lacking.

METHODS: Mobile optical gas imagers (both a miniaturised Schlieren system and sensitive tripod-mounted near-infrared carbon dioxide camera (GF343, FLIR)) prospectively defined trocar-related gas leaks occurring either spontaneously or with instrumentation during planned laparoscopic surgery at three hospitals. A boutique Matlab-based analyser using sequential frame subtraction categorised leaks (class 0-no observable leak; class 1-marginally detectable leak; class 2-short-lived plume; class 3-energetic, turbulent jet). Concurrently, the usefulness of a novel vacuum-ring device (LeakTrap™, Palliare, Ireland) designed as a universal adjunct for existing standard laparoscopic ports at both abdominal wall and port valve level was determined similarly in a phase I/11 clinical trial along with the device's useability through procedural observation and surgeon questionnaire.

RESULTS: With ethical and regulatory approval, 40 typical patients (mean age 58.6 years, 20 males) undergoing planned laparoscopic cholecystectomy (n = 36) and hernia repair (n = 4) were studied comprising both control (n = 20) and intervention (n = 20) cohorts. Dual optical gas imaging was successfully performed across all procedures with minimal impact on procedural flow. In total, 1643 trocar instrumentations were examined, 819 in the control group (mean 41 trocar instrumentations/procedure) and 824 in the intervention group (mean 41.2 trocar instrumentations/procedure). Gas leaks were detected during 948(62.6%) visualised trocar instrumentations (in 129-7.8%-the imaging was obscured). 14.8% (110/742) and 60% (445/742) of leaks in control patients were class 0 and 3, respectively, versus 59.1% (456/770) and 8.7% (67/772) in the interventional group (class 3 v non-class 3, p < 0.0001, χ2 ). The Leaktrap proved surgically acceptable without significant workflow disruption.

CONCLUSION: Laparoscopic gas leaks can be sensitively detected and consistently, effectively mitigated using straightforward available-now technology with most impact on the commonest, highest energy instrument exchange leaks.