Long-term Morphological Changes of Remnant Pancreas and Biliary Tree after Pancreatoduodenectomy on CT

Background. Despite the increasing number of long-term survivors after pancreatoduodenectomy, little is known about morphological appearance of the remnant pancreas or the biliary system after surgery. Methods. To evaluate long-term morphological changes of the remnant pancreas and biliary tree after pancreatoduodenectomy, computed tomograms obtained at the time of surgery and more than 2 years after operation were reviewed in 19 Japanese patients. Results. Two to three years after surgery, parenchymal atrophy of the remnant pancreas occurred in 9 (56%) of 16 patients without atrophy at the time of surgery. Three patients who had had parenchymal atrophy preoperatively showed no change after surgery. Of 10 patients with a dilated pancreatic duct preoperatively, 8 (80%) patients demonstrated a decline in ductal size, while the other 2 showed persistent ductal dilatation. Of 9 patients with a normal-sized pancreatic duct preoperatively, 2 patients (22%) developed ductal dilatation after surgery, and the other 7 showed no change. In 4 (57%) of 7 patients with a dilated hepatic duct preoperatively dilatation was reduced after surgery, whereas it persisted in the remaining 3. Only one (8%) of 12 patients with a non-dilated biliary tree preoperatively showed ductal dilatation 6 months following surgery. Pneumobilia was revealed in 13 (68%) of 19 patients by the follow-up examinations. Conclusions. Surgeons should be aware of these changes in morphology of the remnant pancreas and biliary tree after pancreatectoduodenectomy.