Impact of anthropometric data on technical difficulty of laparoscopic liver of resections of segments 7 and 8: the CHALLENGE index.

Background: The high technical difficulty of using a laparoscopic approach to reach the posterosuperior liver segments is mainly associated with their poor accessibility. This study was performed to analyze correlations between anthropometric data and intraoperative outcomes.

Study Design: All patients who underwent segmentectomy or wedge laparoscopic liver resection (LLR) of segments seven and/or eight from June 2012 to November 2019 were retrospectively analyzed. The exclusion criteria were intrahepatic cholangiocarcinoma, associated resection, multiple concomitant LLR, redo resection, and lack of preoperative imaging. Anthropometric data were correlated with intraoperative outcomes.

Results: Forty-one patients (wedge resection, n = 32; segmentectomy, n = 9) were analyzed. A strong correlation was found between the craniocaudal liver diameter (CCliv) and liver volume (r = 0.655, p < 0.001). The anteroposterior liver diameter was moderately correlated with both the laterolateral abdominal diameter (LLabd) (r = 0.372, p = 0.008) and anteroposterior abdominal diameter (r = 0.371, p = 0.008). The body mass index (BMI) was not correlated with liver diameters. Women had a longer CCliv (p = 0.002) and shorter LLabd (p < 0.001) than men. The liver and abdominal measurements were combined to reduce this sex-related disparity. The CCliv/LLabd ratio (CHALLENGE index) was significantly correlated with the time of transection (r = 0.382, p = 0.037) and blood loss (r = 0.352, p = 0.029). The association between the CHALLENGE index and intraoperative blood loss was even stronger when considering only anatomical resection (r = 0.577, p = 0.048). A CHALLENGE index of > 0.4 (area under the curve, 0.757; p = 0.046) indicated a higher bleeding risk. The BMI predicted no intraoperative outcomes.

Conclusion: Anthropometric data rather than the BMI can help anticipate the difficulty of LLR of segments seven and eight.