Virtual CO2 MDCT pancreatography: a new feasible technique for minimally invasive pancreatectomy in intraductal papillary mucinous neoplasms.

Background/aims: Less invasive pancreatic head resection, such as duodenum-preserving pancreatic head resection (DPPHR) has been introduced for the treatment of pancreatoduodenal lesions, especially for benign conditions, for reducing surgical stress and maintaining exocrine and endocrine function of the residual pancreas in consideration of postoperative quality of life (QOL).

Methodology: We investigated the feasibility of a new technique employing three-dimensional (3D) virtual pancreatography using multi-detector CT (MDCT) with carbon dioxide (CO2) gas as a negative contrast agent for detection of intraductal papillary mucinous neoplasm (IPMN) of the pancreas requiring minimally invasive surgery. Branch IPMN is subjected in this study.

Results: Contrast-enhanced MDCT scan of the abdomen diagnosed 4- to 20-mm multilocular septated cysts in the head-uncinate process of the pancreas. Endoscopic retrograde pancreatography (ERP) showed multiple cystic lesions in the head-uncinate process with mild dilatation in the remaining pancreatic duct. For localizing diagnosis of these small and multiple pancreatic cysts, we placed an endoscopic pancreatic stent (EPS), and MDCT with injection of CO2 via EPS was examined for the virtual CO2 pancreatography, consisting of OsiriX software system employing 3D virtual anatomic reconstruction with CO2 gas as a negative contrast agent. Virtual CO2 MDCT pancreatography demonstrated that all cystic lesions of the pancreas were contained within the area of the head-uncinate process of the pancreas. We performed DPPHR, and surgical margin of the patient's remnant pancreas was determined as non-malignant by intraoperative histology. There was no residual pancreatic cyst and tumor after surgery. The resected tumor was diagnosed as branch duct type intraductal papillary mucinous adenocarcinoma. According to our minimally invasive DPPHR obtained by virtual CO2 pancreatography, the pancreatic endocrine and exocrine functions of this patient were maintained at almost the same levels as those in his preoperative status. With respect to preservation of the endocrine and exocrine functions of the pancreas, DPPHR is a highly effective surgical procedure due to limited surgical resection.

Conclusions: Our new technique of virtual CO2 MDCT pancreatography is a feasible procedure for preservation of the remnant pancreatic function. This is the first report of virtual CO2 pancreatography providing minimally invasive pancreatic surgery.