Endoscopic study of the function of the junction and the timing of epithelialization of the pancreatogastric anastomosis after pancreatoduodenectomy

Abstract

Introduction: the failure of pancreatodigestive anastomosis, as the most common complication after pancreatectomy, can be associated with the complexity of the healing processes of tissues of different embryogenesis, especially when forming an anastomosis between the wall of the gastrointestinal tract and a parenchymal organ, such as the pancreas, which has no serous and mucous membranes, except for the pancreatic duct. So far, the healing processes of pancreatodigestive anastomoses have not been studied. Endoscope access to the pancreatogastrojejunal anastomosis allows visualizing the processes of epithelialization of the pancreatic stump invaded into the gastric lumen. The purpose of the study: to conduct an endoscopic study of the healing processes of the pancreatogastroanastomosis and to determine the timing of pancreatic stump epithelialization. Materials and methods. Pancreatogastroanastomosis at the reconstructive stage of pancreatectomy was used in 35 cases. The pancreatic stump was drained by the lost drainage of the ductus arteriosus and invaded the gastric lumen through the posterior wall. This technique of pancreatoduodenectomy allows for endoscopic examination of the pancreatogastrostomy both in the early and late postoperative period. Endoscopic examination of the pancreatogastrojejunostomy in the postoperative period was performed in 17 patients, with an interval of 1 month to 1 year. Attention was paid to the function of the connection and the timing of anastomotic epithelialization. Patients with pancreatic fistula type B and C were not studied. Results and discussion. By the end of the first month, the pancreatic stump was covered with fibrin, and single, small granulations with areas of epithelialization were seen along its periphery. In the next 3–4 months, there was a circular layering of fresh gastric mucosa, from the periphery to the center of the pancreatic stump. The fresh mucosa filled all the defects and recesses of the anastomosis area. The oculus of the bile duct was visualized as a rounded shape, up to 2 mm in diameter. By the 6th month, the epithelialization of the anastomosis zone was completed. In the following months, the mucous membrane in the anastomosis area was atrophic, with no signs of inflammation. Conclusions: 1. Epithelialization of the pancreatogastroanastomosis occurs due to the layering of fresh gastric mucosa on the invaded pancreatic stump from the periphery to the center. 2. Epithelialization of the invagination begins by the end of the first, beginning of the second month, from 2 to 4 months – intensive layering of the gastric mucosa on the pancreatic stump occurs. After 5 months, the gastric mucosa completely immerses the invaded pancreatic stump, with the surface of the anastomosis area leveled. 3. The healing of the pancreatogastroanastomosis ends at 6 months after surgery. The ductus arteriosus becomes rounded with a diameter of up to 2 mm. In the long-term period, the anastomosis zone is represented by an atrophic mucous membrane with no inflammation and the same color as the surrounding gastric mucosa. 4. Smooth healing of the pancreatogastroanastomosis makes it possible to recommend its use at the reconstructive stage in pancreatoduodenectomy.