Alterations in hemodynamics and hepatic and splanchnic circulation during laparoscopy in rats

Abstract

Background: There is growing evidence that a pneumoperitoneum with increased intraabdominal pressure exerts adverse cardiovascular and splanchnic circulatory effects, whereby portal blood flow, in particular, is disturbed. Methods: Cardiovascular hemodynamics and the blood flow of hollow viscus and solid organs were evaluated in rats undergoing laparotomy, followed by diagnostic carbon dioxide (CO2) laparoscopy with an intraabdominal pressure of either 4 or 10 mmHg and rapid desufflation of the abdominal cavity. The method we employed used g-labeled microspheres and conventional hemodynamic measurements. Results: During CO2 laparoscopy, cardiac output and mean arterial pressure were significantly reduced to between 20.5% and 25% and 14.8% and 18% respectively. After rapid desufflation, cardiovascular hemodynamics normalized to baseline values. During laparoscopy, blood flow in the hollow viscus organs was less disturbed than that in the solid organs. Although small and large bowel blood flow was reduced significantly (26.6% and 23.9%, respectively), gastric blood flow remained unchanged. The decreases in the liver, spleen, pancreas, and kidney circulation were 29-37.2%, 37.6-64.6%, 51.2-57.5%, and 34.8-40.6%, respectively. Total hepatic blood flow was influenced predominantly by portal blood flow, which was particularly decreased; hepatic arterial flow remained stable. Conclusions: Severe alterations in cardiovascular hemodynamics, and to hepatic and splanchnic circulation occur rapidly during CO2 laparoscopy. It can be presumed that both increased intraabdominal pressure and hypercapnia are the main factors underlying these disturbances.