The Effects of Intraabdominally Insufflated Carbon Dioxide on Hepatic Blood Flow During Laparoscopic Surgery Assessed by Transesophageal Echocardiography

Conflicting results have been published about the effects of carbon dioxide (CO2) pneumoperitoneum on splanchnic and liver perfusion. Several experimental studies described a pressure-related reduction in hepatic blood flow, whereas other investigators reported an increase as long as the intraabdominal pressure (IAP) remained less than 16 mm Hg. Our goal in the present study was to investigate the effects of insufflated CO2 on hepatic blood flow during laparoscopic surgery in healthy adults. Blood flow in the right and middle hepatic veins was assessed in 24 patients undergoing laparoscopic surgery by use of transesophageal Doppler echocardiography. Hepatic venous blood flow was recorded before and after 5, 10, 20, 30, and 40 min of pneumoperitoneum, as well as 1 and 5 min after deflation. Twelve patients undergoing conventional hernia repair served as the control group. The induction of pneumoperitoneum produced a significant increase in blood flow of the right and middle hepatic veins. Five minutes after insufflation of CO2 the median right hepatic blood flow index increased from 196 mL/min/m2 (95% confidence interval (CI), 140–261 mL/min/m2) to 392 mL/min/m2 (CI, 263–551 mL/min/m2) (P < 0.05) and persisted during maintenance of pneumoperitoneum. In the middle hepatic vein the blood flow index increased from 105 mL/min/m2 (CI, 71–136 mL/min/m2) to 159 mL/min/m2 (CI, 103–236 mL/min/m2) 20 min after insufflation of CO2. After deflation blood flow returned to baseline values in both hepatic veins. Conversely, in the control group hepatic blood flow remained unchanged over the entire study period. We conclude that induction of CO2 pneumoperitoneum with an IAP of 12 mm Hg is associated with an increase in hepatic perfusion in healthy adults.