Preoperative risk factors for conversion and learning curve of minimally invasive distal pancreatectomy

Background: Although laparoscopic distal pancreatectomy is considered a standard approach, 10% to 40% of these are converted. The preoperative risk factors for conversion are not well described. The aim of this study was to identify risk factors associated with conversion. Methods: Clinicopathological variables of 211 consecutive patients who underwent laparoscopic distal pancreatectomy between January 2007 and December 2015 at Johns Hopkins were analyzed to identify factors associated with conversion. Furthermore, the learning curve for laparoscopic distal pancreatectomy was studied. Results: On univariate analysis of diabetes mellitus, preoperative diagnosis of malignant disease, multiorgan resection, surgeons' years and case experience were significantly associated with conversion (all P < .05). Risk factors independently associated with conversion included diagnosis of malignant disease (odds ratio = 5.40; 95% confidence interval, 1.93-15.12, P = .001), multiorgan resection (odds ratio = 7.10; 95% confidence interval, 1.60-31.53, P = .01), and surgeons' case experience (odds ratio = 0.32; 95% confidence interval, 0.12-0.85, P = .023). Intraoperative reasons for conversion included presence of excessive intraabdominal and retroperitoneal fat (N = 10, 32.3%), adhesions (N = 10, 32.3%), extent of tumor invasion (N = 8, 25.8%), anatomy of vessels (N = 6, 19.4%), and intraoperative bleeding (N = 2, 6.5%). Conclusion: Patients undergoing laparoscopic distal pancreatectomy with a preoperative diagnosis of malignant disease or possible multiorgan resection are at a higher risk of conversion. Surgeon experience of performing >15 procedures significantly reduces the risk of conversion.