PROGNOSTIC IMPACT OF CONSERVATIVE SURGERY FOR PANCREATIC IPMNS

Background: The extent of pancreatic resection for intraductal papillary mucinous neoplasm (IPMN) remains an unresolved issue; in fact, although total pancreatectomy (TP) would definitively prevent metachronous progression to IPMNs or PDACs, metabolic consequences can seriously affect the long-term quality of life. The aim of this study is to analyze the prognostic impact of conservative surgery for pancreatic IPMNs. Methods: We retrospectively analyzed surgical and post-operative data of all pancreatic resections for IPMN performed at our center in a ten-years period, with a minimum follow-up of 24 months. Patients were divided in three different groups based on preoperative indications and post-operative histopathological findings: 1) patients with worrisome features at preoperative imaging undergone pancreatic resection according to the current guidelines and with histopathological proven IPMN with low to high grade dysplasia (IPMN group); 2) patients with IPMN with worrisome features at preoperative imaging undergone pancreatic resection according to current guidelines and with histopathological accidental findings of carcinoma (IPMN-PDAC group); 3) patients with PDAC at preoperative imaging undergone pancreatic resection and with histopathological accidental discovery of collateral IPMN (PDAC-IPMN group). The Kaplan-Meier method was used to compare the overall survival and the disease-free survival of the three groups. Results: From November 2007 to December 2017, 467 patients underwent pancreatic resections, 108 of which had a diagnosis of IPMN. Among these, 25 patients were included in the IPMN group, 20 in the IPMN-PDAC group and 63 in the PDAC-IPMN group. The mean follow-up was 37.13.0 months. A conservative surgery was performed in 55% of patients (36 pancreatoduodenectomies, 23 distal pancreatectomies), while 45% of patients underwent a TP (49). In the IPMN group the OS and DFS were 117.6 and 141.6 months respectively. In the IPMN-PDAC group the OS and DFS were 37.8 and 36.6 months respectively. In this group, 8 patients presented a malignant recurrence. In the PDAC-IPMN group the OS and DFS were 47.9 and 60.8 months respectively. Malignant recurrence was observed in 28 patients. None of patients treated with conservative surgery needed a completion of pancreatectomy due to the progression of IPMN lesions with worrisome features or PDAC in the remnant pancreas during the follow-up. Comparing the OS and the DFS between the three groups, we found a significant difference with a better prognosis only for the IPMN group (p<0.05), while no differences were retrieved between the other two groups. Considering the type of operation, there were not differences between partial or total pancreatectomy in terms of OS and DFS, although there was a higher rate of postoperative surgical complications in patients treated with conservative surgery (p<0.05), but without affecting the length of hospital stay and the 30-day mortality. Only 22.4% of patients developed diabetes after conservative surgery. Conclusion: The prognosis of patients undergoing pancreatic resection for IPMN depends on the presence of malignancy progression of the IPMN into invasive cancer, even if at an early stage, and not on the extension of surgery. A timely, conservative surgery can be considered an appropriate choice, thus avoiding serious long-term metabolic consequences.