Background: Laparoscopic surgery demands mastery of a steep learning curve. Defining a learning curve in laparoscopic surgery is useful for planning training programs or clinical trials. This study aimed to define the learning curves for laparoscopic sigmoidectomy used to manage curable sigmoid colon cancer by evaluating early surgical outcome data from three colorectal surgeons.
Methods: This study analyzed data from 138 consecutive patients undergoing laparoscopic sigmoidectomy for curable sigmoid colon cancer performed by three colorectal surgeons between May 2001 and November 2006. The learning curve for each surgeon were generated using the moving average method to assess changes in operation time and cumulative sum (CUSUM) analysis to assess changes in failure rates [(failure = conversion to open surgery, major perioperative complication, or failure to harvest an adequate number of lymph nodes (<12 nodes)].
Results: Learning curves generated with the moving average method indicated that the operation time reached a steady state after 42 cases for surgeon A, 35 cases for surgeon B, and 30 cases for surgeon C. The overall open conversion rate was 2.9%. There was only one laparoscopy-related perioperative major complication (0.7%). An inadequate number of lymph nodes was harvested in 10 cases (7.2%): 6 (10.5%) for surgeon A, 1 (2.4%) for surgeon B, and 3 (7.7%) for surgeon C. Learning curves generated using CUSUM analysis based on a 90% success rate showed that adequate learning occurred after 10 cases for surgeon A, 17 cases for surgeon B, and 5 cases for surgeon C.
Conclusion: Pertinent learning curves for laparoscopic sigmoidectomy used to manage curable sigmoid colon cancer can be generated using the moving average method and CUSUM analysis. These results are likely to be useful in designing laparoscopic training programs and clinical trials aimed at investigating outcomes of laparoscopic colorectal cancer surgery.