Factors associated with and impact of open conversion on the outcomes of minimally invasive left lateral sectionectomies: An international multicenter study

Background: Despite the rapid advances that minimally invasive liver resection has gained in recent decades, open conversion is still inevitable in some circumstances. In this study, we aimed to determine the risk factors for open conversion after minimally invasive left lateral sectionectomy, and its impact on perioperative outcomes. Methods: This is a post hoc analysis of 2,445 of 2,678 patients who underwent minimally invasive left lateral sectionectomy at 45 international centers between 2004 and 2020. Factors related to open conversion were analyzed via univariate and multivariate analyses. One-to-one propensity score matching was used to analyze outcomes after open conversion versus non-converted cases. Results: The open conversion rate was 69/2,445 (2.8%). On multivariate analyses, male gender (3.6% vs 1.8%, P =.011), presence of clinically significant portal hypertension (6.1% vs 2.6%, P =.009), and larger tumor size (50 mm vs 32 mm, P <.001) were identified as independent factors associated with open conversion. The most common reason for conversion was bleeding in 27/69 (39.1%) of cases. After propensity score matching (65 open conversion vs 65 completed via minimally invasive liver resection), the open conversion group was associated with increased operation time, blood transfusion rate, blood loss, and postoperative stay compared with cases completed via the minimally invasive approach. Conclusion: Male sex, portal hypertension, and larger tumor size were predictive factors of open conversion after minimally invasive left lateral sectionectomy. Open conversion was associated with inferior perioperative outcomes compared with non-converted cases.