Geometric modification of Billroth-II gastric resection with computational fluid dynamics (CFD) method: assessment of anastomotic leak and duodenogastric reflux risks

There are two main problems in research on gastric surgery: life-threatening complications and clinical follow-up. Computational fluid dynamics can be used as a tool to identify the source of these problems and provide solutions to improve gastric resection procedures. In this study, geometric configurations that can be applied in surgery for Billroth-II gastric resection with jejunojejunostomy anastomosis were presented. The effects of these geometric configurations on the anastomotic leak and leakage of pancreatic juice and bile into the stomach (duodenogastric reflux) risks were investigated numerically. Finite volume method was preferred for numerical analyses. The SIMPLE algorithm for the pressure–velocity coupling and the second-order scheme for the pressure correction were applied. First-order UPWIND and second order UPWIND schemes were used in the mass transport and discretization of conservation equations, respectively. Numerical analyzes were performed for different gastroenterostomy anastomosis suture angles (α), the ratios of afferent loop length to suture width (L/D), and the ratio of the distance between the gastroenterostomy and jejunojejunostomy anastomoses to the suture width (H/D). For both when the stomach was mostly full or empty, it was determined that the best results were obtained for α = 30°, H/D = 2.5 and L/D = 5 in terms of anastomotic leak and duodenogastric reflux risks. It was concluded that in Billroth-II gastric resection with jejunojejunostomy anastomosis, giving an angle with positive slope to the suture, increasing the afferent loop length, and keeping the jejunojejunostomy anastomosis at a distance of at least 2.5 times the suture width from the gastroenterostomy anastomosis reduces the risks of anastomotic leak and duodenogastric reflux.