Conversion from robotic surgery to laparotomy: a case-control study evaluating risk factors for conversion.

Objectives: To determine risk factors associated with conversion to laparotomy for women undergoing robotic gynecologic surgery.

Methods: The medical records of 459 consecutive robotic surgery cases performed between December 2006 and October 2011 by 8 different surgeons at a single institution were retrospectively reviewed. Cases converted to laparotomy were compared to those completed robotically. Descriptive statistics were used to summarize the demographic and clinical characteristics.

Results: Forty of 459 (8.7%, 95% CI 6.3%-11.7%) patients had conversion to open surgery. Reason for conversion included poor visualization due to adhesions (13), inability to tolerate Trendelenburg (7), enlarged uterus (7), extensive peritoneal disease (5), bowel injury (2), ureteral injury (1), vascular injury (1), bladder injury (1), technical difficulty with the robot (2), and inability to access abdominal cavity (1). 5% of cases were converted prior to docking the robot. On univariate analysis, preoperative diagnosis (p=0.012), non-White race (p=0.004), history of asthma (p=0.027), ASA score (p=0.032), bowel injury (p=0.012), greater BMI (p<0.001), need for blood transfusion (p<0.001), and expected blood loss (p<0.001) were associated with conversion. On multivariate analysis, non-White race (OR 2.88, 95% CI 1.39-5.96, p=0.004), bowel injury (OR 35.40, 95% CI 3.00-417.28, p=0.005), and increasing BMI (OR 1.06, 95% CI 1.03-1.09, p<0.001) were significantly associated with increased risk for conversion. Prior surgery was not associated with conversion to open surgery (p=0.347).

Conclusion: Conversion to laparotomy was required for 8.7% of patients undergoing robotic surgery for a gynecologic indication. Increasing BMI and non-white race were identified as the two preoperative risk factors associated with conversion.