# Nationwide implementation of minimally invasive liver surgery: population-based analysis

## TL;DR

This study shows that minimally invasive liver surgery became more common in Sweden over 15 years and improved short-term outcomes without harming long-term survival.

## Contribution

The study provides nationwide data on the implementation and outcomes of minimally invasive liver surgery for colorectal liver metastases.

## Key findings

- Minimally invasive liver surgery increased over time and improved short-term outcomes like reduced blood loss and complications.
- Robotically assisted procedures rose rapidly in the later period.
- Outcomes for minimally invasive surgery were as good as open surgery in terms of survival and resection rates.

## Abstract

Previous studies of minimally invasive liver surgery described results and experiences in high-volume centres and early adopters, but data on national levels are lacking. This study evaluated the implementation and outcomes of minimally invasive liver surgery in Sweden over a 15-year period, with a focus on colorectal liver metastases.

Data from patients undergoing liver surgery between 2009 and 2023 were obtained from the Swedish National Quality Registry for Liver, Gallbladder and Bile Duct Cancer, and evaluated in time intervals. Propensity score matching analysis was used to compare outcomes between open and minimally invasive liver surgery for colorectal liver metastases.

A total of 9977 procedures were included in the study, of which 1490 (14.9%) were minimally invasive. Minimally invasive liver surgery was used increasingly over time, and had better short-term outcomes than open liver operations, including less blood loss (median 200 (interquartile range 50–400) versus 500 (250–1000) ml; P < 0.001), fewer major complications (127 (9.3%) versus 1697 (21.9%); P < 0.001), and a lower 30-day mortality rate (6 patients (0.4%) versus 107 (1.3%); P = 0.004). Use of robotically assisted liver surgery increased over time and it constituted 311 minimally invasive liver procedures (38.4%) in the late time period. Propensity score matching analysis for patients with colorectal liver metastases showed reduced blood loss with minimally invasive liver surgery (P < 0.001), a similar rate of radical resections, and similar overall survival.

The study demonstrated safe nationwide implementation of minimally invasive liver surgery. Use of the minimally invasive approach increased over time, including a rapid rise for robotically assisted procedures in the later period. Minimally invasive liver surgery maintained or improved favourable short-term outcomes without adverse effects on morbidity, mortality or long-term survival after surgery for colorectal liver metastases.

The study analysed the implementation of minimally invasive liver surgery (MILS) in Sweden over 15 years. The rate of MILS increased over time, including a fast rise in robotically assisted liver surgery in the later period. MILS maintained or improved favourable short-term outcomes without adverse effects on morbidity, mortality or long-term survival for patients with colorectal liver metastases, in the full cohort and a propensity score-matched cohort.