Validation of a Difficulty Scoring System for Laparoscopic Liver Resection: A Multicenter Analysis by the Endoscopic Liver Surgery Study Group in Japan.

Background: Laparoscopic liver resection (LLR) is widely used for hepatic disease treatment. Preoperative prediction of operative difficulty can be beneficial as a roadmap for surgeons advancing from simple to highly technical LLR. We performed a multicenter analysis to investigate a "difficulty scoring system" for predicting the difficulty of LLR.

Study Design: The proposed "difficulty scoring system" includes 3 difficulty levels based on 5 factors. The system was validated in a cohort of 2,199 patients who underwent LLR at 74 Japanese centers between 2010 and 2014; the difficulty level was rated as low (n = 965), intermediate (n = 891), and high (n = 343). Operative parameters, postoperative complications, and outcomes were compared according to the difficulty levels.

Results: The median operation time and blood loss were 258 minutes (range 30 to 1,275 minutes) and 75 mL (range 0 to 7,798 mL), respectively. The overall conversion rate was 5.0% (n = 110). The incidences of postoperative complications, liver failure, and in-hospital death were 5.3% (n = 116), 1.5% (n = 32), and 0.5% (n = 12), respectively. Median hospital stay was 9 days (range 1 to 189 days). Conversion rate, operation time, and blood loss showed a direct correlation with the difficulty level. A strong correlation was observed among the difficulty level, incidence of postoperative complications, and hospital stay. Incidence of postoperative liver failure and in-hospital death in the high difficulty group was higher than that in the low difficulty group.

Conclusions: Preoperative evaluation with the "difficulty scoring system" predicted the difficulty of the operation and the postoperative outcomes of LLR. In the beginning of LLR training, surgeons should start with low difficulty-level operations.