# Evaluating pneumoperitoneum pressure in robotic liver surgery: a propensity-score matched analysis in a high-volume center in Scandinavia

## TL;DR

This study compares low versus standard pneumoperitoneum pressure in robotic liver surgery and finds no significant differences in outcomes.

## Contribution

The study evaluates the safety and efficacy of using 10 mmHg pneumoperitoneum pressure in robotic liver surgery without central venous pressure management.

## Key findings

- No significant differences in blood loss, operating time, or complications between low and standard pneumoperitoneum pressure groups.
- Low pneumoperitoneum pressure (10 mmHg) was found to be feasible and safe for robotic liver surgery.
- Gas embolism was not observed in either group during the study.

## Abstract

Minimally invasive liver surgery usually involves the use of standard pneumoperitoneal pressure (12–15 mmHg) and low central venous pressure (CVP) management to reduce intraoperative bleeding while hereby possibly increasing the risk for gas embolism. The purpose of this study is to evaluate the efficacy and safety of low pneumoperitoneum pressure (Low-PP: 10 mmHg) compared to standard pneumoperitoneum pressure (Standard-PP: 12 mmHg) in patients undergoing robotic liver surgery (RLS) without active CVP management.

A single-center retrospective cohort study was conducted from June 2019 to February 2024. Propensity-score matching analysis (1:1) was performed based on age, sex, BMI, ASA classification, diagnosis, and extent of resection (minor or major) for Low-PP group to Standard-PP group. The primary outcome were estimated blood loss (EBL), operating time (OT), length of stay (LOS), and complications (Clavien–Dindo classification).

Before the propensity-score matching (PSM) analysis, the Low-PP group comprised 63 patients and the Standard-PP group comprised 130 patients. Following PSM analysis, each group comprised 62 patients. The pringle maneuver was performed significantly more frequently in the Low-PP group (87.1% vs 50.0%, p < 0.001). There were no statistically significant differences with regards EBL, OT, LOS, or overall/major complications between the two groups. Intraoperative anesthetic parameters were comparable, and no signs of gas embolism were observed in either group. In a subgroup analyis for minor and major resections, no statistically significant differences were observed in perioperative outcomes between the groups.

Our study did not find any statistically significant difference in perioperative outcomes of patients undergoing RLS at a pneumoperitoneal pressure of 10 mmHg versus 12 mmHg. We therefore conclude that performing RLS using a pneumoperitoneal pressure of 10 mmHg PP is feasible and safe. Randomized controlled trials are needed to further investigate the potential and benefit of this strategy.

The online version contains supplementary material available at 10.1007/s00464-025-12283-2.