The blood supply to the body and tail of the pancreas comes from the dorsal and great pancreatic branches of the splenic artery. The short gastrics arise from the hilar branches of the splenic artery. The splenic artery may divide early into a few major branches, or late near the hilum into multiple small branches. The former makes splenectomy easier.
The pancreas drains into the splenic and portal veins via multiple small branches. Dividing these branches and preserving the major trunks is tedious. The branches from the head of the pancreas drain into the right side of the portal vein. To avoid these branches, a finger is passed beneath the neck of the pancreas to the left side of the portal vein when assessing resectability of a pancreatic head tumor