A pancreatic fistula refers to an abnormal connection between the pancreas and another organ or space caused by the leakage of powerful pancreatic enzymes from either the injured pancreatic duct or from a pancreatic pseudocyst. It usually occurs in association with pancreatitis, but may also be a complication of surgical manipulation or abdominal trauma. This condition is usually treated by restriction of food intake, administration of somatostatin analogues, and in worst cases, surgical or endoscopic treatment.
There are two major types of pancreatic fistula. The first one is called external pancreatic fistula, or pancreaticocutaneous fistula, called as such because of the abnormal communication of the pancreas and the skin. Pancreatic secretions are rich in bicarbonate, a substance that helps maintain the normal potenz hydrogen (pH) of the blood. When a pancreaticocutaneous fistula occurs the bicarbonate-rich secretions evaporate, leading to acidosis or a decrease in blood pH.
The second type is called internal pancreatic fistula because the pancreas communicates with other intra-abdominal organs or spaces. When pancreatic secretions enter the peritoneal cavity, they are called pancreatic ascites. If the mediastinum or the central thoracic compartment is affected, it is called enzymatic mediastinitis. In cases where the pleural covering of the lungs is affected, it is called pancreatic pleural effusion, or pancreatico-pleural fistula.
Pancreatitis, or inflammation of the pancreas, is the most common precedent of a pancreatic fistula. Acute pancreatitis results from excessive alcoholic intake and gallbladder disorders like gallstones. Chronic pancreatitis commonly results from alcoholism in adults, and is linked to abdominal trauma in children. Traumatic injury to the pancreas is rare because the pancreas is relatively protected by its retroperitoneal location. An important but uncommon precedent is pancreatic surgery for malignancies or for necrotizing pancreatitis.
Diagnosis of a pancreatic fistula is performed by analysis of the fluid within the pleura or the abdominal cavity. When the level of amylase, a pancreatic enzyme, is greater than 1,000 international units (IU) per liter, and the level of pancreatic proteins is greater than 3.0 g/dL, the diagnosis is confirmed. Computed tomography (CT) with contrast can help localize the fistula. A useful diagnostic procedure for biliary tract disorders, called endoscopic retrograde cholangiopancreatography (ERCP), may also aid in the diagnosis.
Treating a pancreatic fistula is challenging because pancreatic enzymes are needed for the digestion of food taken orally. The guiding principles include no oral intake of food, total parenteral nutrition, and administration of somatostatin analogues like octreotide, which is supposed to inhibit pancreatic secretion. Endoscopic treatment through ERCP and the placement of a stent or drain may be performed to decrease the pressure in the pancreatic duct. If conservative and endoscopic treatments fail, surgical treatment through pancreatic resection or pancreaticoduodenectomy can be done.