Evaluation of the learning curve in laparoscopic low anterior resection for rectal cancer

Abstract

Background: Laparoscopic low anterior resection for rectal cancer is considered to be more technically demanding than laparoscopic colectomy. This study aimed to analyze the learning curve for laparoscopic low anterior resection and to identify the factors that influence this learning curve.

Methods: Data from 250 consecutive patients undergoing laparoscopic low anterior resection for rectal cancer, excluding patients with a combined resection such as cholecystectomy, hepatectomy, hysterectomy, or gastrectomy, between December 1996 and April 2010 were analyzed. For operative time, the learning curve was analyzed using the moving average method. The conversion rate and the postoperative complication rate were evaluated in five groups of up to 50 patients each based on the number of cases required for analysis of operative time. In addition, risk factors that influenced conversion to open surgery and postoperative complications were analyzed.

Results: The learning curve analysis for operative time using the moving average method showed stabilization at 50 cases. The conversion rate decreased significantly by group 4 (151-200 cases). The postoperative complication rate decreased significantly by group 5 (201-250 cases). The significant factors for conversion to open surgery were male sex (odds ratio [OR], 2.6094; 95% confidence interval [CI], 1.1-6.4) and T stage (OR, 2.4793; 95% CI, 1.1-5.8). For postoperative complications, male sex (OR, 3.8590; 95% CI, 1.9-3.8) was significant. In addition, the risk factors for anastomotic leakage were male sex (OR, 15.7659, 95% CI, 3.2-284.8) and multiple firing (2 or more cartridges for rectal transection) (OR, 3.0589; 95% CI, 1.1-9.5).

Conclusions: The risk factors affecting the learning curve for laparoscopic low anterior resection were T stage and male sex. In laparoscopic low anterior resection, rectal transection in particular can be technically difficult, and standardization for accurate performance of the same technique for expanded indications is very important.