Safety and feasibility of outpatient minimally invasive liver resection under an ERAS-based comprehensive management protocol: a propensity score-matching study

Background: Outpatient minimally invasive liver resection may reduce hospital stay and costs, but concerns remain regarding early postoperative safety. The goal of this study was to evaluate the safety and feasibility of outpatient minimally invasive liver resection (oMILR) within an enhanced recovery after surgery (ERAS)-based comprehensive management protocol.

Methods: We retrospectively analyzed 1,343 patients who underwent minimally invasive liver resection between January 2023 and September 2025. Patients were assigned to the oMILR or inpatient MILR (iMILR) group according to treatment pathway. Propensity score matching was performed at 1:3 for the primary analysis and 1:1 for sensitivity analysis. Outcomes included perioperative recovery, length of stay, in-hospital costs, 90-day complications, mortality, unplanned readmission, post-discharge healthcare utilization and delayed discharge in the oMILR cohort. Within the oMILR cohort, we further examined the reasons for delayed discharge and explored preoperative characteristics associated with failure to discharge within 48 hours.

Results: Before matching, 93 patients underwent oMILR and 1,250 underwent iMILR. Of the 93 patients managed through the oMILR pathway, 81 (87.1%) were discharged within 48 hours and 12 (12.9%) required delayed discharge. In the 1:3 matched cohort, 77 oMILR patients were compared with 221 iMILR patients. Compared with the iMILR group, the oMILR group had a shorter operative time, less intraoperative blood loss, earlier postoperative ambulation, shorter drainage tube duration, shorter total and postoperative hospital stays, and lower in-hospital costs (all P < 0.001). Ninety-day overall complications (9.1% vs 10.4%, P = 0.74), mortality (0% in both groups), unplanned readmission (1.3% vs 0.9%, P > 0.99) and post-discharge healthcare utilization were similar between groups. The sensitivity analysis based on 1:1 matching showed consistent overall results. Delayed discharge was mainly related to anatomical complexity and the extent of liver resection, yet the statistical power was insufficient due to the small sample size.

Conclusions: In rigorously screened patients undergoing predominantly minor or benign hepatic resections, oMILR pathway reduces hospital stay and in-hospital costs when supported by mature minimally invasive techniques and standardized ERAS-based comprehensive management protocol. In this selected cohort, outpatient management was not associated with an observable increase in short-term adverse outcomes. The relevant conclusions should not be generalized to unselected MILR populations. Exploratory delayed-discharge findings suggest that resection extent and segmental anatomical complexity may deserve further evaluation in future oMILR eligibility frameworks, but these factors should not yet be regarded as validated selection criteria.