Single-incision laparoscopic cholecystectomy learning curve experience seen in a single institution

Single-incision laparoscopic surgery (SILS) is laparoscopic surgery done by one incision through the umbilicus. Cholecystectomy lends itself well to a SILS approach. As these procedures have become more widely adapted, it is important to determine the approximate learning curve to decrease two surgical endpoints: (1) time to completion of the procedure; and (2) decreased incidence of conversion.

We prospectively reviewed our series of 50 cholecystectomies done using the SILS approach between May 2008 to September 2008. All cases were performed by two advanced laparoscopic surgeons at a single institution. Data was collected immediately after the case and entered into an Excel database. Cases were performed by insufflating the abdomen with a Veress needle through the umbilicus followed by placement of 5-mm ports at the umbilicus.

Patient ages ranged between 21 and 82 years with a median age of 45 years. Body mass index (BMI) range was 21 to 42 kg/m with a mean of 30 kg/m. Average length of time for cases was 1 hour 9 minutes with a range between 55 minutes and 120 minutes. The average length of time for the first 25 cases was 80 minutes. When compared with cases 26 to 50 the average length of time was 60 minutes (P<0.05). The conversion rate to conventional laparoscopic cholecystectomy was 10%. Conversion was accomplished through the addition of a 5-mm port elsewhere on the abdominal cavity. After the tenth case, the incidence of conversion went down to zero. When conversions were further stratified, they occurred within each individual surgeon's first ten cases.

The learning curve for successful consistent completion of SILS cholecystectomy cases appears to be after 25 cases. In addition, conversion rates drop dramatically after the first ten cases.