Proper management and follow-up strategy of branch duct intraductal papillary mucinous neoplasms of the pancreas

Background and aim: It has been reported that main duct intraductal papillary mucinous neoplasms are more invasive and have a worse prognosis than branch duct intraductal papillary mucinous neoplasms. Therefore, an aggressive surgical approach has mainly been recommended for all MD-IPMNs. However, the surgical management of BD-IPMNs has been controversial and the consensus guidelines are not specific for an indicator of malignancy in BD-IPMNs. The objective of this study was to determine the proper management and follow-up strategy of BD-IPMNs. Methods: We monitored and analysed patients with presumed BD-IPMNs between March 1995 and March 2010. Result: The mean value of the initial cyst size in all patients with BD-IPMNs was 2.19. cm. Amongst 194 patients with BD-IPMNs, 34 underwent immediate surgical resection, 152 were followed conservatively. Amongst the 152 conservatively managed patients, 18 (11.8%) underwent surgical resection after a median follow-up of 12.7 months (range, 3-48 months). In 132 patients who were managed conservatively without surgery, the mean incremental rate of cyst size growth was 0.0038. cm/month during a median of 30.7 months of follow-up and there were no IPMN-related deaths. Conclusion: Amongst patients with BD-IPMNs, about 10% have surgery within approximately 1 year from the time of diagnosis because of the occurrence of new malignant stigmata. Therefore, a conservative approach without surgery and careful follow-up every 3 months or 6 months during the first year after diagnosis can be safely advocated in patients with BD-IPMNs larger than 10 mm in size who have no risk factors for malignant IPMNs.