Parenchymal-sparing hepatectomy for colorectal liver metastases reduces postoperative morbidity while maintaining equivalent oncologic outcomes compared to non-parenchymal-sparing resection

Abstract

Abstract Objective Modern chemotherapy and repeat hepatectomy allow to tailor the surgical strategies for the treatment of colorectal liver metastases (CRLM). This study addresses the hypothesis that parenchymal-sparing hepatectomy reduces postoperative complications while ensuring similar oncologic outcomes compared to the standardized non-parenchymal-sparing procedures. Methods Clinicopathological data of patients who underwent liver resection for CRLM between 2012 and 2019 at a major hepatobiliary center in Switzerland were assessed. Patients were stratified according to the tumor burden score [TBS2 = (maximum tumor diameter in cm)2 + (number of lesions)2)] and were dichotomized in a lower and a higher tumor burden cohort according to the median TBS. Postoperative outcomes, overall survival (OS) and disease-free survival (DFS) of patients following parenchymal-sparing resection (PSR) for CRLM were compared with those of patients undergoing non-PSR. Results During the study period, 153 patients underwent liver resection for CRLM with curative intent. PSR was performed in 79 patients with TBS < 4.5, and in 42 patients with TBS ≥ 4.5. In patients with lower tumor burden (TBS < 4.5), PSR was associated with lower complication rate (15.2% vs. 46.2%, p = 0.009), and shorter length of hospital stay (5 vs. 9 days, p = 0.006) in comparison to non-PSR. For TBS < 4.5, PSR resulted in equivalent 5-year OS (48% vs. 39%, p = 0.479) and equivalent 5-year DFS rates (DFS, 44% vs. 29%, p = 0.184) compared to non-PSR. For TBS ≥ 4.5, PSR resulted in lower postoperative complication rate (33.3% vs. 63.2%, p = 0.031), lower length of hospital stay (6 vs. 9 days, p = 0.005), equivalent 5-year OS (29% vs. 22%, p = 0.314), and equivalent 5-year DFS rates (29% vs. 22%, p = 0.896) compared to non-PSR. Among all patients treated with PSR, patients undergoing minimal-invasive hepatectomy had equivalent 5-year OS (42% vs. 37%, p = 0.261) and equivalent 5-year DFS (34% vs. 34%, p = 0.613) rates compared to patients undergoing open hepatectomy. Conclusion PSR for CRLM is associated with lower postoperative morbidity, shorter length of hospital stay, and equivalent oncologic outcomes compared to non-PSR independently from tumor burden. Our findings suggest that minimal-invasive PSR should be considered as the preferred method for the treatment of curatively resectable CRLM if allowed by tumor size and location.