Risk factors of unplanned intraoperative conversion to hand-assisted laparoscopic surgery or open surgery in laparoscopic liver resection.

Background: Laparoscopic liver resection (LLR) is possible in many patients, but pure LLR is sometimes difficult to complete, and unplanned intraoperative hand-assisted laparoscopic surgery (HALS) or open conversion is sometimes necessary. However, appropriate indications and timing for conversion are unclear. This study aimed to clarify the indications for HALS and open conversion from pure LLR.

Methods: We collected data from 208 patients who underwent LLR from January 2010 to February 2021 in our department. We retrospectively examined these data between cases of unplanned intraoperative HALS conversion, open conversion, and pure LLR, and clarified risk factors and indications for HALS or open conversion.

Results: There were 191 pure LLRs, nine HALS conversions, and eight open conversions. In the HALS conversion group versus pure LLR group, body mass index (BMI) (27.0 vs. 23.7 kg/m, p = 0.047), proportions of patients with history of upper abdominal surgery (78% vs. 33%; p = 0.006), repeat hepatectomy (56% vs. 15%; p = 0.002), S7 or S8 tumor location (67% vs. 35%; p = 0.049), and difficulty score (DS) ≥ 7 (56% vs. 19%; p = 0.008) were significantly higher, and surgical time (339 vs. 239 min; p = 0.031) was significantly longer. However, postoperative states were not significantly different between the two groups. The BMI cutoff value for risk of unplanned intraoperative conversion determined by receiver operating characteristic curve analysis was 25 kg/m, and the proportion of patients with BMI ≥ 25 kg/m (89% vs. 31%, p < 0.001) was significantly higher in the HALS conversion versus pure LLR group. In the open conversion group, although there were no significant differences compared to the HALS group in clinicopathological factors except for sex, blood loss was greater (1425 vs. 367 mL; p < 0.001).

Conclusion: Risk factors for considering HALS during LLR were patients with a history of upper abdominal surgery including repeat hepatectomy, BMI ≥ 25 kg/m, S7 or S8 tumor location, DS ≥ 7, and prolonged surgical time. Furthermore, uncontrollable intraoperative bleeding was an indication for open conversion.