Paracholedochal varices causing biliopathy in a case of portal vein thrombosis.

A 35-year-old male was presented with a history of recurrent acute pancreatitis. An abdominal ultrasound showed extrahepatic portal vein thrombosis, normal biliary system and dilated pancreatic duct. Endoscopic ultrasound (EUS) was done to look for biliary system microliths and chronic pancreatitis. It showed features consistent with chronic pancreatitis, portal vein thrombosis and multiple paracholedochal collaterals causing tortuous and irregular common bile duct (CBD) as shown in Figures 1 and 2, consistent with portal hypertensive biliopathy. His liver function tests were normal. Regular follow-up was advised to the patient.

Figure 1

Radial endoscopic ultrasound image showing multiple collaterals causing compression of common bile duct, portal vein is not visualized

Figure 2

Linear endoscopic ultrasound image showing multiple collaterals causing compression of common bile duct

DISCUSSION

Biliary ductal abnormalities secondary to extrahepatic portal venous obstruction (EHPVO) occurs in 80-100% of patients, these changes are less common in patients with other causes of portal hypertension (cirrhosis 0-33%, idiopathic portal hypertension 9-40%). Higher prevalence of portal hypertensive biliopathy in EHPVO is probably related to long standing portal hypertension in these patients. Symptomatic portal biliopathy (CBD stone leading to cholangitis or stricture leading to cholestasis) is seen in <10% of affected patients.[1] Differential diagnosis of portal hypertensive biliopathy related strictures include primary and secondary sclerosing cholangitis, gallstone disease, ischemic cholangiopathy, AIDS cholangiopathy, autoimmune or recurrent pancreatitis, eosinophilic cholangitis, mast cell cholangiopathy, recurrent pyogenic cholangitis, surgical or blunt trauma and parasitic diseases.[2] The pathogenesis of portal hypertension related strictures include compression by collaterals, mural changes and ischemia (caused by venous supply damage secondary to portal vein thrombosis). The venous drainage of CBD is by veins that ascend along its course, these veins form two plexuses, epicholedochal (on CBD wall) and paracholedochal (parallel to CBD) venous plexus. High venous pressure secondary to portal vein obstruction can be transmitted to these plexuses, and it causes irregular mural changes in the CBD, direct compression by enlarging collaterals and ischemic changes due to portal vein block.[13] Based on magnetic resonance cholangiopancreatography findings, there may be varicoid (smooth indentations by paracholedochal collaterals), fibrotic (stricture) or mixed changes.[3] Asymptomatic patients do not need any treatment if the liver function tests are normal. Management strategies for symptomatic patients include endoscopic stone removal, stenting (if cholangitis secondary to stricture is present) or shunt surgery,[1] generally shunt surgery improves the obstruction, but sometimes bilioenteric anastomosis may be needed.[4] Caution is needed during endoscopic retrograde cholangiopancreatography (ERCP) as there are chances of bleeding from intracholedochal varices and periampullary veins during endoscopic sphincterotomy.[15] Collaterals within CBD appear as filling defects during ERCP and they may bleed from basket manipulation, hence balloon use may be safe (filling defect will not move if it is a varix).[1] EUS may play a great role in minimizing risk of bleeding during ERCP in these patients as periampullary or intracholedochal collaterals can be identified and true stones can be picked up. We feel that EUS should be recommended in these patients (based on availability and cost) before ERCP.