The learning curve of laparoscopic liver resection utilizing a difficulty score

Abstract

Background: This study aimed to quantitatively evaluate the learning curve of laparoscopic liver resection (LLR) of a single surgeon.

Methods: A retrospective review of a prospectively maintained database of liver resections was conducted. 171 patients undergoing pure LLRs between April 2008 and April 2021 were analysed. A difficulty score by Halls et al. for theoretical predictions of IOC during LLR was applied. IOC was defined as blood loss over 775 mL, unintentional damage to the surrounding structures, and conversion to an open approach. The Halls difficulty score (HDS) includes the following parameters: neoadjuvant chemotherapy, previous open liver resection, benign or malignant lesion, lesion size, and classification of resection. Theoretical association between HDS and predicted probability of IOC was utilized to objectify the shape of the learning curve.

Results: The learning curve results from thirteen years of effort (absolute complexity) and a quintic regression line of relative complexity (HDS).

Conclusion: This learning curve indicates an ongoing learning process for LLR. The proposed mathematical model can be applied for any surgical procedure with an existing difficulty score and a known theoretically predicted association between the difficulty score and given outcome (for example, IOC).