Pedicle clamping with ischemic preconditioning in liver resection

Hepatic pedicle clamping (HPC) is widely used to control intraoperative bleeding during hepatectomy; intermittent HPC is better tolerated but is associated with blood loss during each period of reperfusion. Recently, it has been shown that ischemic preconditioning (IP) reduces the ischemia-reperfusion damage for up to 30 minutes of continuous clamping in healthy liver. We evaluated the safety of IP for more prolonged periods of continuous clamping in 42 consecutive patients with healthy liver submitted to hepatectomy. IP was used in 21 patients (group A); mean +/- SD of liver ischemia was 54 +/- 19 minutes (range, 27-110; in 7 cases >60 minutes). In the other 21 patients, continuous clamping alone was used (Group B); liver ischemia lasted 36 +/- 14 minutes (range, 13-70; in 2 cases >60 minutes). Two patients in Group A (9.5%) and 3 in Group B (14.2%) received blood transfusions. In spite of the longer duration of ischemia (P=.001), patients with IP had lower aspartate aminotransferase (AST; P=.03) and alanine aminotransferase (ALT; P=not significant) at postoperative day 1, with a similar trend at postoperative day 3. This was reconfirmed by multiple regression analysis, which showed that although postoperative transaminases increased with increasing duration of ischemia and of the operation in both groups, the increases were significantly smaller (P<.001) with the use of preconditioning. In conclusion, the present study confirms that IP is safe and effective for liver resection in healthy liver and is also better tolerated than continuous clamping alone for prolonged periods of ischemia. This technique should be preferred to continuous clamping alone in healthy liver. Additional studies are needed to assess the role of IP in cirrhotic liver and to compare IP with intermittent clamping.