IMAGE OF THE MONTH Gastrointestinal Bleeding Caused by Pancreatic Arteriovenous Malformation Tanima Jana,* Jorge D. Machicado,* and Sushovan Guha‡ *Department of Internal Medicine, ‡Division of Gastroenterology, Hepatology and Nutrition, University of Texas Medical School at Houston, Houston, Texas
48-year-old African American man presented to the emergency department with hematemesis. He complained of abdominal pain and weight loss for the past 6 months. His history was significant for type 2 diabetes mellitus. On physical examination, the abdomen was tender to palpation in the left upper quadrant. Laboratory data showed mild anemia (hemoglobin level, 11.7) and transaminitis (alanine aminotransferase level, 125; aspartate aminotransferase level, 220). The rest of the biochemistry, hepatobiliary, and coagulation studies were normal. Esophagogastroduodenoscopy was normal. Computed tomography of the abdomen (Figure A) showed a heterogenous pancreatic head, a dilated portal vein of 1.9 cm (Figure A, asterisk) and early portal venous filling during the arterial phase. Magnetic resonance imaging of the abdomen showed dilated portal and splenic vein filling during the arterial phase and extensive peripancreatic vasculature. A 1.8-cm choledochal cyst was found in the head of the pancreas, communicating with the second portion of the duodenum. Endoscopic ultrasound showed collateral vessels from the head to the tail of the pancreas. Endoscopic retrograde cholangiopancreatography showed a type III choledochal cyst (Figure B, arrow) with a fistulous connection to the duodenum. In light of the continued decrease in hemoglobin level, the patient underwent conventional angiography, which showed a diffuse vascular blush in the body of the pancreas (Figure C, superior mesenteric artery), with early filling of the portal vein
A
during the arterial phase (Figure C, asterisk). A final diagnosis of pancreatic arteriovenous malformation (AVM) was made. Transjugular liver biopsy showed a hepatic venous pressure gradient of 3 mm Hg and normal histopathology. Although a Whipple procedure was considered, it ultimately was not attempted because there was no disease-free pancreas available for anastomosis and extensive pancreatic vascularization was present. The patient was managed symptomatically, and at the 1-year follow-up evaluation, his pain was well controlled without recurrence of gastrointestinal bleeding. Pancreatic AVM is a rare condition in which blood flows directly from the arterial to venous circuit while bypassing capillary vessels.1,2 Since the first description by Halpern in 1968,3 approximately 80 cases have been reported in the literature. Although its etiology is unknown, proposed causes include congenital malformation (90%) and acquired causes such as trauma, tumor, or inflammation.2 Half of the patients present with gastrointestinal bleeding, 40% complain of abdominal and/or back pain, and 20% are asymptomatic.1 The mechanisms of GI bleeding in patients with pancreatic AVM include ischemia of the duodenal mucosa leading to duodenal ulcer (50%), esophageal or gastric varices from portal hypertension (42%), hemobilia (12%), or pancreatic duct bleeding (8%).4 None of these causes was identified in our patient. Erosion of the AVM into the choledochal cyst was the most plausible mechanism of GI bleeding. The diagnostic modality of choice for Clinical Gastroenterology and Hepatology 2014;-:-–-
IMAGE OF THE MONTH, continued pancreatic AVM is angiography. Other noninvasive tests such as Doppler ultrasound, dynamic computed tomography, and magnetic resonance imaging might be helpful, but findings are not specific. Treatment options include surgery, transarterial embolization, transjugular intrahepatic portosystemic shunt, and radiation.1,2 Surgical resection is widely considered the most successful therapy but cannot always be performed, as was the case in our patient. In conclusion, clinicians should recognize pancreatic AVM in the differential diagnosis of gastrointestinal bleeding and be familiar with the diagnostic work-up that leads to its diagnosis.
References 1.
2
Song KB, Kim SC, Park JB, et al. Surgical outcomes of pancreatic arteriovenous malformation in a single center and review of literature. Pancreas 2012;41:388–396.
2.
Chou SC, Shyr YM, Wang SE. Pancreatic arteriovenous malformation. J Gastrointest Surg 2013;17:1240–1246.
3.
Halpern M, Turner AF, Citron BP. Hereditary hemorrhagic telengiectasia. An angiographic study of abdominal visceral angiodysplasias associated with gastrointestinal hemorrhage. Radiology 1968;90:1143–1149.
4.
Hosogi H, Ikai I, Hatano E, et al. Pancreatic arteriovenous malformation with portal hypertension. J Hepatobiliary Pancreat Surg 2006;13:344–346.
Conflicts of interest The authors disclose no conflicts. © 2014 by the AGA Institute 1542-3565/$36.00 http://dx.doi.org/10.1016/j.cgh.2014.02.009
48-year-old African American man presented to the emergency department with hematemesis. He complained of abdominal pain and weight loss for the past 6 months. His history was significant for type 2 diabetes mellitus. On physical examination, the abdomen was tender to palpation in the left upper quadrant. Laboratory data showed mild anemia (hemoglobin level, 11.7) and transaminitis (alanine aminotransferase level, 125; aspartate aminotransferase level, 220). The rest of the biochemistry, hepatobiliary, and coagulation studies were normal. Esophagogastroduodenoscopy was normal. Computed tomography of the abdomen (Figure A) showed a heterogenous pancreatic head, a dilated portal vein of 1.9 cm (Figure A, asterisk) and early portal venous filling during the arterial phase. Magnetic resonance imaging of the abdomen showed dilated portal and splenic vein filling during the arterial phase and extensive peripancreatic vasculature. A 1.8-cm choledochal cyst was found in the head of the pancreas, communicating with the second portion of the duodenum. Endoscopic ultrasound showed collateral vessels from the head to the tail of the pancreas. Endoscopic retrograde cholangiopancreatography showed a type III choledochal cyst (Figure B, arrow) with a fistulous connection to the duodenum. In light of the continued decrease in hemoglobin level, the patient underwent conventional angiography, which showed a diffuse vascular blush in the body of the pancreas (Figure C, superior mesenteric artery), with early filling of the portal vein
A
during the arterial phase (Figure C, asterisk). A final diagnosis of pancreatic arteriovenous malformation (AVM) was made. Transjugular liver biopsy showed a hepatic venous pressure gradient of 3 mm Hg and normal histopathology. Although a Whipple procedure was considered, it ultimately was not attempted because there was no disease-free pancreas available for anastomosis and extensive pancreatic vascularization was present. The patient was managed symptomatically, and at the 1-year follow-up evaluation, his pain was well controlled without recurrence of gastrointestinal bleeding. Pancreatic AVM is a rare condition in which blood flows directly from the arterial to venous circuit while bypassing capillary vessels.1,2 Since the first description by Halpern in 1968,3 approximately 80 cases have been reported in the literature. Although its etiology is unknown, proposed causes include congenital malformation (90%) and acquired causes such as trauma, tumor, or inflammation.2 Half of the patients present with gastrointestinal bleeding, 40% complain of abdominal and/or back pain, and 20% are asymptomatic.1 The mechanisms of GI bleeding in patients with pancreatic AVM include ischemia of the duodenal mucosa leading to duodenal ulcer (50%), esophageal or gastric varices from portal hypertension (42%), hemobilia (12%), or pancreatic duct bleeding (8%).4 None of these causes was identified in our patient. Erosion of the AVM into the choledochal cyst was the most plausible mechanism of GI bleeding. The diagnostic modality of choice for Clinical Gastroenterology and Hepatology 2014;-:-–-
IMAGE OF THE MONTH, continued pancreatic AVM is angiography. Other noninvasive tests such as Doppler ultrasound, dynamic computed tomography, and magnetic resonance imaging might be helpful, but findings are not specific. Treatment options include surgery, transarterial embolization, transjugular intrahepatic portosystemic shunt, and radiation.1,2 Surgical resection is widely considered the most successful therapy but cannot always be performed, as was the case in our patient. In conclusion, clinicians should recognize pancreatic AVM in the differential diagnosis of gastrointestinal bleeding and be familiar with the diagnostic work-up that leads to its diagnosis.
References 1.
2
Song KB, Kim SC, Park JB, et al. Surgical outcomes of pancreatic arteriovenous malformation in a single center and review of literature. Pancreas 2012;41:388–396.
2.
Chou SC, Shyr YM, Wang SE. Pancreatic arteriovenous malformation. J Gastrointest Surg 2013;17:1240–1246.
3.
Halpern M, Turner AF, Citron BP. Hereditary hemorrhagic telengiectasia. An angiographic study of abdominal visceral angiodysplasias associated with gastrointestinal hemorrhage. Radiology 1968;90:1143–1149.
4.
Hosogi H, Ikai I, Hatano E, et al. Pancreatic arteriovenous malformation with portal hypertension. J Hepatobiliary Pancreat Surg 2006;13:344–346.
Conflicts of interest The authors disclose no conflicts. © 2014 by the AGA Institute 1542-3565/$36.00 http://dx.doi.org/10.1016/j.cgh.2014.02.009
