Comparison and validation of three difficulty scoring systems in laparoscopic liver surgery: a retrospective analysis on 300 cases

Difficulty scores (DSs) have been proposed to rate laparoscopic liver resection (LLR) technical difficulty increasing surgical safety. The aim of the study was to validate three DSs (Hasegawa, Halls and Kawaguchi) and compare their ability to predict technical difficulty and postoperative outcomes. All patients who underwent LLR from January 2006 to January 2019 were analyzed. Exclusion criteria were cyst fenestrations, thermal ablation, missing data for the computation of the DS and a follow-up < 90 days. The population comprised 300 patients. The DS distribution in the study population was: Halls low 55 (18.3%), moderate 82 (27.3%), high 111 (37%) and extremely high 52 (17.3%); Hasegawa low 130 (43.3%), medium 105 (35%) and high 65 (21.7%); Kawaguchi Grade I 194 (64.7%), Grade II 47 (15.7%) and Grade III 59 (19.7%). Hasegawa and Kawaguchi showed the strongest correlation (r = 0.798, p < 0.001). Technical complexity, evaluated using the Pringle maneuver, Pringle time, blood loss and operative time, increased significantly with Hasegawa and Kawaguchi score classes (p < 0.001 for all comparisons). None of the scores properly stratified postoperative complications. The highest Kawaguchi (23.7% grade III vs. 13.7% grades I and II, p = 0.057) and Hasegawa (24.6% high vs. 13.2% low/medium, p = 0.025) classes had a higher overall morbidity rate than medium–low ones. Kawaguchi and Hasegawa scores predicted LLR’s technical difficulty. None of the scores discriminated the postoperative complication risk of low classes compared with medium ones.