Validation of difficulty scoring system for laparoscopic liver resection in patients who underwent laparoscopic left...

A difficulty scoring system (DSS) based on the extent of liver resection, tumor location, liver function, tumor size, and tumor proximity to major vessels was recently developed to assess the difficulty of various laparoscopic liver resection procedures. We validated DSS in patients who underwent laparoscopic left lateral sectionectomy (LLS).

We reviewed the clinical data of 124 patients who underwent laparoscopic LLS between July 2003 and November 2015 and validated the DSS in 90 patients who underwent laparoscopic LLS for tumor according to their surgical outcomes. We also developed and evaluated the modified DSS in 34 patients who underwent LLS for intrahepatic duct (IHD) stones.

The DSS score ranged from 3 to 6 in laparoscopic LLS for tumors. The median blood loss (P = 0.002) was significantly different among patients divided into subgroups by DSS score. We made modified DSS for IHD stones using factors influencing longer operation time, including stone location (P = 0.002), atrophy of liver parenchyma (P = 0.012), ductal stricture <1 cm from the bifurcation (P = 0.047), and combined choledochoscopic examination for remnant IHD (P < 0.001). The modified DSS score for IHD stones ranged from 3 to 7. Blood loss (P = 0.02) and operation time (P < 0.001) were significantly different among subgroups of patients divided by their difficulty scores. The median hospital stay (P = 0.004) and operation time (P = 0.039) were significantly longer and the complication rate (P = 0.025) and complication grade (P = 0.021) were significantly greater in patients with IHD stones than in patients with tumors.

The surgical difficulty varies among patients undergoing the same laparoscopic LLS procedure. The modified DSS developed here can also be applied to patients with IHD stones.