Parenchymal-Sparing Surgery for the Surgical Treatment of Multiple Colorectal Liver Metastases Is a Safer Approach than Major Hepatectomy Not Impairing Patients' Prognosis: A Bi-Institutional Propensity Score-Matched Analysis

Background: The performance of parenchymal-sparing hepatectomy (PSH) versus major hepatectomy (MH) in patients with multiple colorectal liver metastases (CLM) is a matter that is yet debated. We investigated the outcome of patients with multiple CLM undergoing PSH instead of MH. Methods: Databases at 2 institutions were reviewed. A propensity score-matched analysis was applied. Among 554 patients, 110 undergoing PSH and 110 undergoing MH were matched. They were similar in baseline characteristics, comorbidity, and tumor features. Primary outcomes were short- and long-term outcomes. Results: Morbidity was significantly higher in the MH group, while mortality was not significantly different. There were no differences in free-margins width, but a trend of increased survival was seen in the PSH group with a median advantage of 6 months over the MH group. Among the prognostic factors, the T status (hazard ratio [HR] 2.6; p = 0.001), the N status (HR 2.9; p = 0.001), the timing of CLM diagnosis (HR 2.1; p = 0.002), the tumor number (HR 2.0; p = 0.001), the tumor size (HR 2.2; p = 0.015), and the neo-adjuvant chemotherapy (HR 1.7; p = 0.023) were found to be statistically and independently significant for survival. Conclusions: PSH conveys advantage over MH in terms of decreased postoperative morbidity, and a trend of survival benefit. PSH should be considered a suitable alternative to MH whenever it is technically feasible.