Effects of portal triad clamping on haemodynamic conditions during laparoscopic liver resection

To evaluate the haemodynamic effects of portal triad clamping (PTC) during laparoscopic liver resection, 10 patients without cardiac disease were studied by invasive monitoring including a pulmonary artery catheter and were compared with a control group of 10 patients undergoing liver resection by laparotomy. During laparoscopic surgery, intra-abdominal pressure was kept below 14 mm Hg and minute ventilation was adjusted to prevent hypercapnia. Measurements were made before PTC (T1), 5 min after PTC (T2) and 5 min after clamp release (T3). During clamping with pneumoperitoneum, mean arterial pressure (MAP) remained stable (+2%; not significant), systemic vascular resistance (SVR) increased by 37% (P<0.01, T2 vs T1) and cardiac index (CI) decreased by 19% (P<0.01, T2 vs T1). During laparotomy and clamping, MAP increased by 18% (P<0.01, T2 vs T1), SVR increased by 36% (P<0.01, T2 vs T1) and CI decreased by 9% (not significant). We were unable to demonstrate a difference in haemodynamic changes during clamping with pneumoperitoneum vs the open surgical technique, but in a small number of patients this lack of difference could have been a result of inadequate statistical power. The haemodynamic changes that we found were well tolerated in these patients, who had normal cardiac function.