Elevated intrahepatic pressures and decreased hepatic tissue blood flow prevent gas embolus during limited laparoscopic liver resections

Background: As new techniques are emerging for laparoscopic liver resections, concerns have been raised about the development of gas embolus related to the CO2 pneumoperitoneum. We hypothesized that elevated intrahepatic vascular pressures and decreased hepatic tissue blood flow (LQ(B)) would prevent gas embolus during laparoscopic liver resections under conventional pneumoperitoneum. Methods: Intrahepatic vascular pressures and LQ(B) were measured in nine pigs with varying CO2 pneumoperitoneum. Gas embolus was determined after hepatic incision by monitoring pulmonary arterial pressure (PAP), hepatic venous P-CO2, systemic blood pressure (SBP), and suprahepatic vena cava ultrasound. Results: As the pneumoperitoneum was increased from 0 to 15 mmHg, intrahepatic vascular pressures increased significantly 0, < 0.05), while LQ, decreased significantly (p < 0.05). A 2.0-cm hepatic incision at 4, 8, 15, and 20mmHg produced no ultrasound evidence of gas embolus and no changes in PAP, SEP, or hepatic venous P-CO2 (p = NS). Conclusion: These data suggest that the risk of significant embolus under conventional pneumoperitoneum is minimal during laparoscopic liver resections.