Safety first: significant risk of air embolism in laparoscopic gasketless insufflation systems

Abstract

Background

Gasketless laparoscopic insufflator systems are marketed for the ability to prevent desufflation of pneumoperitoneum during laparoscopy. However, surgeons raised concern for possible introduction of non-absorbable room air, including oxygen (O₂), with these systems. A community-university collaborative was created to test this hypothesis.

Methods

An artificial abdomen, calibrated to equivalent compliance and volume of an average abdomen, was connected to a flow meter, oxygen concentration sensor, and commercially available laparoscopic gasketless cannula system. A commercially available gasketed cannula system was utilized as a control. Intra-abdominal concentration of oxygen was measured at 0–60 L per minute (L/min) of insufflated carbon dioxide (CO₂) aspiration, as would occur during laparoscopic suctioning. For reference, a 5-mm laparoscopic suction device has an aspiration rate of approx. 42 L per minute. At the test facility, room air was 20.5% O₂ at 50% humidity. Descriptive and univariate statistics were calculated with p < 0.05 considered significant.

Results

At 0 L/min CO₂ aspiration, there was minimal (< 0.5%) oxygen detected intra-abdominally. However, with increasing rates of aspiration of pneumoperitoneum, increasing amounts of room air were detected intraabdominally in the gasketless versus gasketed cannula systems (mean ± standard deviation): 14.7 ± 1.2% versus 1.2 ± 0.5%, p < 0.0001 at 5 L/min aspiration, 18.1 ± 0.69% versus 1.1 ± 0.02%, p < 0.0001 at 10 L/min, 50.4 ± 2.19% vs 1.01 ± 0.003%, p < 0.0001 at 20 L/min. Above 25 L/min aspiration, the standard gasketed cannula systems experienced desufflation, but the gasketless system continued to entrain air to maintain insufflation: 64% room air at 30 L/min aspiration, 71% at 40 L/min aspiration, 77% at 50 L/min aspiration, and 84% at 60 L/min aspiration.

Conclusions

Gasketless cannula insufflation systems maintain abdominal insufflation by entraining non-medical room air. Especially at high aspiration rates, the majority of absorbable CO₂ was replaced by non-medical room air, increasing potential for gas embolism with poorly absorbed oxygen and nitrogen. Authors have reported these experimental findings to the FDA and companies marketing these devices.