History and Physical Examination
Most patients with visceral artery pseudoaneurysms are asymptomatic. Symptomatic pseudoaneurysms can be nonspecific and require a high index of suspicion to establish the correct diagnosis. Symptoms include the following [14] :
-
Fatigue
-
Nausea
-
Vomiting
-
Weight loss
-
Pain in the chest, back, flank, and abdomen
-
Bleeding from an intra-abdominal drain placed at the time of surgery
-
Anemia of unexplained cause
-
Recurrent or intermittent hematemesis or hematochezia in patients who have pancreatitis, particularly when due to chronic alcohol abuse or trauma
-
Rapid enlargement of a pseudocyst or a pulsatile abdominal mass, especially in the presence of abdominal bruit and hyperamylasemia
-
The syndrome known as hemosuccus pancreaticus, characterized by bleeding from the ampulla of Vater, colicky pain, and jaundice
Patients with pancreatitis may have the following symptoms:
-
Persistent or abrupt increase in abdominal pain
-
Decreasing hematocrit values and/or hemodynamic instability and/or gastrointestinal (GI) bleeding with no obvious intraluminal cause
Because pancreatitis is the most common underlying cause of pancreatic pseudoaneurysm, most patients are males with alcoholism (80-90%) who have a history of episodic chronic pancreatitis and secondary pseudocyst formation.
The diagnosis of visceral artery pseudoaneurysm should be considered in any patient with a pseudocyst and a significant abdominal bruit.
Bleeding-associated pain
The clinical picture may vary widely. The most common form of bleeding is probably rupture into a pseudocyst, with eventual bleeding through the pancreatic duct (duct of Wirsung) and, subsequently, the ampulla of Vater if the pseudocyst is connected with the pancreatic duct. This "Wirsungorrhagia" (ie, hemosuccus pancreaticus) manifests as intermittent pain caused by sudden filling with blood and resultant distention of the pancreatic duct and may sometimes be accompanied by elevated levels of pancreatic enzymes.
Once the intraductal pressure reaches a certain level, the bleeding stops and a clot forms. The clot subsequently lyses at a later stage, leading the cycle to repeat itself.
On the other hand, if the pseudocyst does not communicate with the duct of Wirsung, then blood accumulates in the pseudocyst, leading to sudden enlargement and causing abdominal pain and a drop in the hematocrit value.
Complications
The most life-threatening complications of pseudoaneurysms are rupture and subsequent hemorrhage. A pancreatic pseudoaneurysm tends to enlarge when subjected to sufficient intracystic pressure, ultimately rupturing into the GI tract, biliopancreatic ducts, pseudocyst, peritoneal cavity, or retroperitoneum.
Hemorrhage carries a mortality of 13-40% and is almost always fatal if left unattended. Bleeding is usually brisk, but it varies from short, repeated, and self-limiting episodes to massive hemorrhage requiring emergency laparotomy.
The frequency of arterial lesion hemorrhage during pancreatitis ranges from 5% to 10%. However, when pseudocysts are present, the hemorrhage rate rises to 15-20% of cases.
The most common site of rupture is intracystic; the incidence of spontaneous hemorrhage arising from a pancreatic pseudocyst reportedly ranges from 1.4% to 8.4%. This bleeding can be localized in the cyst, causing sudden enlargement and abdominal pain, or bleeding can occur through the cyst into the pancreatic duct if a communication between these structures exists. (In this case, the patient will have GI bleeding.)
Other sites of rupture include the biliopancreatic duct, peritoneal cavity, and retroperitoneum; sometimes, direct erosion into the duodenum and other parts of the GI tract will occur.
Other, infrequent complications of pancreatic pseudoaneurysms include arteriovenous fistula formation and extrahepatic biliary tract obstruction.
-
Splenic artery angiogram demonstrating contrast (white arrow) extravasating into a pseudoaneurysm (black arrow).
-
A CT scan with intravenous contrast enhancement (arrow) within a pancreatic pseudocyst indicating the presence of a pseudoaneurysm.
-
Preembolization angiogram depicting a splenic artery pseudoaneurysm.
-
Postembolization angiogram depicting successful coil embolization of a pseudoaneurysm.
