Inferior head resection of the pancreas for intraductal papillary mucinous neoplasms

Previous reports have suggested that patients with intraductal papillary mucinous neoplasm (IPMN) have a favorable prognosis after surgical resection. Thus, a variety of types of partial pancreatic resections have been advocated for treating these low-grade malignant tumors. However, the surgical outcome of IPMN after such limited pancreatectomy has not been fully clarified.

We performed a retrospective review of the clinicopathologic features and surgical outcome in 15 patients who underwent inferior head resection for IPMN at the Chiba University Hospital and National Cancer Center Hospital East between July 1994 and January 2007.

There were 13 patients with noninvasive IPMNs (10 adenomas and 3 noninvasive carcinomas) and 2 patients with minimally invasive intraductal papillary mucinous carcinoma (minimally invasive IPMN). Complete tumor removal (R0 resection) was performed in four patients (80%) with intraductal papillary mucinous carcinoma. Subsequent pancreatoduodenectomy was performed in one patient because of noninvasive carcinoma with multiple mucous lakes in the pancreatic parenchyma. Values for N-benzoyl-l-tyrosyl-p-aminobenzoic acid excretion test results before (n = 13) and after (n = 13) the operation were 70.7 and 66.1, showing no significant difference. The 2-h glucose levels in the 75 g oral glucose tolerance test before (n = 13) and after (n = 13) the operation were 133 and 146 mg/dl, respectively, showing no significant difference. Pancreatic fistula occurred in 7 (47%) patients. Overall morbidity and mortality rates were 67 and 0%, respectively. The overall 1-, 3-, 5-, and 10-year survival rates for the 15 patients were 100, 79, 79, and 71%, respectively. The 1-, 3-, 5-, and 10-year survival rates for patients with noninvasive IPMN (n = 13) and those with minimally invasive IPMN (n = 2) were 100, 92, 92, and 83%; and 100, 0, 0, and 0%, respectively. There was a significant difference in survival between patients with noninvasive IPMN and those with minimally invasive IPMN (p = 0.0005). No patient with noninvasive IPMN developed recurrent disease. One patient with minimally invasive IPMN died of recurrent peritoneal dissemination 18 months after margin-positive R1 resection. Two patients died of pancreatic ductal adenocarcinoma, 30 and 78 months after inferior head resection.

Pancreatic endocrine and exocrine function was well preserved after inferior head resection. Pancreatic fistula occurred more frequently after inferior head resection than with conventional pancreatoduodenectomy. Patients with noninvasive IPMN had favorable survivals after this procedure. However, one patient with minimally invasive IPMN with margin-positive R1 resection died of recurrent disease. Thus, margin-negative R0 resection should be performed for IPMN.