Effects of Prolonged Pneumoperitoneum on Hepatic Perfusion During Laparoscopy

Objective: To assess the influence of prolonged pneumoperitoneum (PP) on liver function and perfusion in a clinically relevant porcine model of laparoscopic abdominal insufflation. Background: PP during laparoscopic surgery produces increased intraabdominal pressure, which potentially influences hepatic function and microcirculatory perfusion. Methods: Six pigs (49.6 ± 5.8 kg) underwent laparoscopic intra-abdominal insufflationwith 14mmHgCO2 gas for 6 hours, followed by a recovery period of 6 hours. Two animals were subjected to 25 mm Hg CO2 gas. Hemodynamic parameters were monitored, and damage parameters in the blood were measured to assess liver injury. Liver total blood flowand functionwere determined by the indocyanine green (ICG) clearance test. Intraoperative hepatic hemodynamics were measured by simultaneous reflectance spectrophotometry (venous oxygen saturation StO2 and relative tissue hemoglobin concentration rHb) and laser Doppler flowmetry (blood flow and flow velocity). Postmortem liver samples were collected for histological evaluation. Results: Adecrease inmicrovascular perfusionwas observed during PP. After 6 hours of PP, ICG clearance increased (P<0.001), indicating a compensatory improvement of overall liver blood flow resulting in concomitantly improved microcirculatory perfusion (P = 0.024). Minimal parenchymal damage (aspartate aminotransferase) of the liver was seen after 6 hours of PP (P = 0.006), which seemed related to PP pressure. Minor histological damage was observed. Conclusions: The liver sustains no additional damage due to prolonged PP during laparoscopic surgery. Our findings suggest that prolonged PP does not hamper liver function or cause liver damage after extended laparoscopic procedures.