Ischemic preconditioning versus intermittent clamping of portal triad in liver resection: A meta-analysis of randomized controlled trials

Aim: To compare the clinical outcome of patients undergoing liver resection under ischemic preconditioning (IP) versus intermittent clamping (IC). Methods: A systematic published work search was conducted to detect randomized controlled trials (RCT) comparing IP and intermittent clamping of the portal triad. A meta-analysis was conducted to estimate postoperative morbidity and mortality, blood loss, transfusion requirement, and liver injury based on the levels of bilirubin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Meta-analysis was performed using either the fixed-effects model or random-effects model. Results: Five RCT published between 2006 and 2012 containing a total of 403 patients were eligible for final analysis. Meta-analysis of operative time showed it was lower in the IP group than the IC group with weighted mean difference (WMD) of -18.23 (95% confidence interval (CI), -28.58 to -7.87; P=0.0006). Meta-analysis of ALT levels indicated lower levels in the IP group on postoperative days 3 and 7 (WMD on day 3: -45.27, 95% CI, -49.92 to -40.62; P<0.00001; I²=0%; WMD on day 7: -24.33, 95% CI, -28.04 to -20.62; P<0.00001; I²=0%). Meta-analyses revealed no significant difference in blood loss, transfusion requirement, mortality, morbidity, ischemic duration, hospital stay, AST and bilirubin levels on postoperative days 1, 3 and 7, and ALT levels on postoperative day 1 between IP and IC groups. Conclusion: On currently available evidence, IP does not offer a satisfying benefit to patients undergoing hepatic resection. However, they have lower operative time and less liver injury after liver resections.