It involves a side-to-side anastomosis of the pancreatic duct and the jejunum.
[1] The operation involves creating a longitudinal incision along the pancreas while the main pancreatic duct is filleted open longitudinally from the head of the organ to its tail.
One advantage of this procedure compared to a Frey's procedure is that pancreatic tissue is preserved, which may be of critical importance in patients with exocrine or endocrine insufficiency from their chronic pancreatitis.
The main pancreatic duct needs to be 6mm in diameter in the body of the pancreas for this procedure to be possible.
One of the problems that can lead to failure of the Puestow procedure is that pain can persist due to failure to drain the pancreatic duct on the head of the pancreas.