Meta-analysis of ischemic preconditioning (IP) on postoperative outcomes after liver resections

Abstract

Background:The protective role (decrease ischemia-reperfusion injury) of ischemic preconditioning (IP) before continuous vascular occlusion in liver resection is controversial. This meta-analysis aimed to compare the advantages and any potential disadvantages of IP maneuver.Methods:A systematic search in the Embase, Medline, PubMed databases, and the Cochrane Library was performed using both medical subject headings (MeSH) and truncated word searches to identify all randomized controlled trials (RCTs) published on this topic. The primary outcomes were postoperative morbidity, mortality, postoperative aspartate aminotransferase (AST) level, alanine aminotransferase (ALT) level, and total bilirubin (TB) level. Pooled odds ratios (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (95% CIs) were calculated using either the random effects model or fixed effects model.Results:Thirteen RCTs involving 918 patients were analyzed to achieve a summated outcome. The patients have been divided into IP group (n = 455) and no IP group (n = 463) before continuous vascular occlusion. No significant difference was found in postoperative mortality between both groups (P = .30). Subgroup analysis revealed that the postoperative morbidity in the cirrhosis subgroup was significantly less for the IP group compared with the control group (P = .01). In the cirrhosis subgroup, the result was stable (P = .04), without heterogeneity (P = .59; I2 = 0%). Meta-analysis of AST level on postoperative day (POD) 1 indicated lower postoperative AST level in the IP group (P = .04). The analysis of ALT level showed lower ALT level in the IP group versus control group (P = .02). However, there was no difference in postoperative AST and ALT level after excluding 1 study with statistical heterogeneity (all P > .05). With respect to postoperative TB level, there was no significant difference between 2 groups.Conclusion:IP cannot decrease the hospital mortality for patients undergoing hepatectomy. IP may be beneficial for patients with cirrhosis due to less morbidity in patients with liver cirrhosis. However, we cannot conclude that IP can decrease ischemia-reperfusion injury because it did not significantly decrease postoperative AST, ALT, and TB levels.

Direct, remote and combined ischemic conditioning in liver surgery

“…Another meta-analysis was published in 2017[ 31 ]. The authors focused only on RCTs investigating the role of IPC before CC.…”

Liver resection in Cirrhotic liver: Are there any limits?

“…iv. A recent meta-analysis on the protective role of ischemic preconditioning before the Pringle maneuver (hepatic inflow occlusion) during liver resection concluded that ischemic preconditioning may be beneficial for cirrhotic patients by significantly reducing postoperative morbidity compared with the control group, based on six randomized control trials that enrolled both cirrhotic and noncirrhotic patients [71]. v. Splenectomy in cirrhotic patients with hypersplenism has been reported to alleviate liver function, improve immunological response, and reduce HCC recurrence [72][73][74].…”

Ischemic Preconditioning on Liver Ischemia Reperfusion Injury: How Far is the Bedside from the Bench?

“…Its beneficial effects in clinical trials of liver resection and liver transplantation are controversial [18][19][20][21]. A meta-analysis of 13 randomized control trials involving 913 patients that underwent liver resection failed to find any statistically significant difference in morbidity or mortality rates among study participants [22]. Subgroup analysis revealed that the postoperative morbidity in the cirrhosis subgroup and the cirrhosis subgroup was significantly less for the IPC group compared with the control group.…”

“…A possible explanation for this discrepancy is that the magnitude of the benefit conferred by IPC is proportional to the severity of the IR injury [24]. In the majority of clinical studies, IPC was more effective in reducing IRI in subjects with steatotic or cirrhotic livers [22]. Furthermore, these conflicting results may also be caused by the IPC protocols that vary between studies and are unlikely to be optimal.…”