Institution learning curve of laparoscopic colectomy—a multi-dimensional analysis

Abstract

This study aimed to evaluate the learning curve for laparoscopic colorectal resection of a university colorectal unit, the operative outcome in its developing and established period of laparoscopic colorectal resection is compared. We analyzed 1,031 consecutive patients who underwent laparoscopic colorectal resections for colorectal carcinoma performed in a colorectal unit between April 1992 and December 2008. Multi-dimensional analyses of the learning curves of the institution and seven individual surgeons were performed. The operative outcomes of period 2 (2002-2008) was generally better than period 1 (1992-2001), in terms of operative time, number of lymph nodes retrieved, intra-operative blood loss and transfusion. The conversion rate of period 1 was higher than period 2 (19.7% vs. 5.1%, p < 0.001). There were no difference in the rates of intra-operative complications (2% vs. 3.3%, p = 0.32) and major post-operative complications (6% vs. 4.5%, p = 0.28). Analysis of the operative time using moving average method showed that the operative time of period 2 was generally shorter than that of period 1. The operative time transiently increased when there were new trainee surgeons joining the program. The CUSUM analysis of institutional conversion rate showed a steady state being reached at 310 cases. For the rates of intra-operative and major post-operative complications, steady states were both achieved at around 50 cases, and these rates were maintained during the whole study period. Operative outcome of laparoscopic colorectal resection improved with experience. Continuous training of new trainee would not affect the operative outcomes of an established specialized unit.