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

Abstract

BACKGROUND\nModern 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.\n\n\nMETHODS\nClinicopathological data of patients who underwent liver resection for CRLM between 2012 and 2019\xa0at a hepatobiliary center in Switzerland were assessed. Patients were stratified according to the tumor burden score [TBS2 = (maximum tumor diameter in cm)2\xa0+\xa0(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 recurrence-free survival (RFS) of patients following parenchymal-sparing resection (PSR) for CRLM were compared with those of patients undergoing non-PSR.\n\n\nRESULTS\nDuring 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. Perioperative chemotherapy was administered in equal rates in both groups (PSR vs. non-PSR) both in TBS ≥4.5 and TBS <4.5. In patients with lower tumor burden (TBS <4.5), PSR was associated with lower overall complication rate (15.2% vs. 46.2%, p\xa0=\xa00.009), a trend for lower major complication rate (8.9% vs. 23.1%, p\xa0=\xa00.123), and shorter length of hospital stay (5 vs. 9 days, p\xa0=\xa00.006) in comparison to non-PSR. For TBS <4.5, PSR resulted in equivalent 5-year OS (48% vs. 39%, p\xa0=\xa00.479) and equivalent 5-year RFS rates (44% vs. 29%, p\xa0=\xa00.184) compared to non-PSR. For TBS ≥4.5, PSR resulted in lower postoperative complication rate (33.3% vs. 63.2%, p\xa0=\xa00.031), a trend for lower major complication rate (23.8% vs. 42.2%, p\xa0=\xa00.150), lower length of hospital stay (6 vs. 9 days, p\xa0=\xa00.005), equivalent 5-year OS (29% vs. 22%, p\xa0=\xa00.314), and equivalent 5-year RFS rates (29% vs. 18%, p\xa0=\xa00.156) compared to non-PSR. Among all patients treated with PSR, patients undergoing minimal-invasive hepatectomy had equivalent 5-year OS (42% vs. 37%, p\xa0=\xa00.261) and equivalent 5-year RFS (34% vs. 34%, p\xa0=\xa00.613) rates compared to patients undergoing open hepatectomy.\n\n\nCONCLUSIONS\nPSR for CRLM is associated with lower postoperative morbidity, shorter length of hospital stay, and equivalent oncologic outcomes compared to non-PSR, independently of 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.