Postoperative morbidity after liver resection- A Systemic review, meta-analysis, and metaregression of factors affecting them.

Aim of the studyThis systemic review and meta-analysis aimed to analyze post-operative morbidity after liver resection, and also study various factors associated with mortality via metaregression analysis. Material and MethodsPubMed, Cochrane Library, Embase, google scholar, web of science with keywords like liver resection"; "mortality";" hepatectomy". Weighted percentage post-operative morbidities were analyzed. Meta-analysis and meta-regression were done by the DerSimonian-Liard random effect model. Heterogeneity was assessed using the Higgins I2 test. Publication bias was assessed using a funnel plot. Funnel plot asymmetry was evaluated by Eggers test. Morbidity was defined as any postoperative morbidity mentioned. ResultsA total of 46 studies was included in the final analysis. Total 45771 patients underwent liver resections. 16111 patients experienced complications during the postoperative period. Weighted post-operative morbidity was 30.2% (95 % C.I. 24.8-35.7%). Heterogeneity was high with I2 99.46% and p-value <0.01. On univariate analysis, major liver resections were significantly associated with heterogeneity. (p=0.024). However, residual heterogeneity was still high with I2 98.62%, p<0.001. So, multifactor metaregression analysis major hepatectomy (p<0.001), Open hepatectomy (p=0.001), cirrhotic liver (p=0.002), age (p<0.001), blood loss (p<0.001), and colorectal metastasis (p<0.001) independently associated with postoperative morbidity. Residual heterogeneity was moderate I2= 39.9% and nonsignificant p=0.189. ConclusionLiver resection is associated with high postoperative morbidity and various factors like major hepatectomy, Open hepatectomy, cirrhotic liver, blood loss, and colorectal metastasis were associated with morbidity and responsible for heterogeneity across the studies.