The preoperative M2BPGi score predicts operative difficulty and the incidence of postoperative complications in laparoscopic liver resection

Background Liver fibrosis or cirrhosis frequently makes parenchymal transection more difficult, but the difficulty score of laparoscopic liver resection (LLR), including the IWATE criteria, does not include a factor related to liver fibrosis. Therefore, this study aimed to evaluate M2BPGi as a predictor of the difficulty of parenchymal transection and the incidence of postoperative complications in LLR. Methods Data from 54 patients who underwent laparoscopic partial liver resection (LLR-P) and 24 patients who underwent laparoscopic anatomical liver resection between 2017 and 2019 in our institution were retrospectively analyzed. All cases were classified according to M2BPGi scores, and reserve liver function, intraoperative blood loss, and postoperative complications were compared among these groups. Results Sixteen cases (29.6%) were M2BPGi negative (cut-off index < 1.0), 25 cases (46.3%) were 1+ (1.0 <= cut-off index < 3.0), and 13 cases (24.1%) were 2+ (cut-off index >= 3.0). M2BPGi-positive cases had significantly worse hepatic reserve function (K-ICG: 0.16 vs 0.14 vs 0.08, p < 0.0001). Intraoperative bleeding was significantly greater in M2BPGi-positive cases [50 ml vs 150 ml vs 200 ml, M2BPGi (-) or (1+) vs M2BPGi (2+), p = 0.045]. Postoperative complications (Clavien-Dindo >= II) were significantly more frequent in M2BPGi-positive cases [0% vs 4% vs 33%, M2BPGi (-) or (1+) vs M2BPGi (2+), p = 0.001]. Conclusion M2BPGi could predict surgical difficulty and complications in LLR-P. In particular, it might be better not to select M2BPGi (2+) cases as teaching cases because of the massive bleeding during parenchymal transection.