Institution Learning Curve of Laparoscopic Colectomy--a Multi-dimensional Analysis

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.