An unusual cause of acute cholangitis†

Abstract

An 84-year-old woman with a history of a 4-cm abdominal aortic aneurysm presented with fever, chills, nausea, and right upper quadrant abdominal pain for 12 hours. Pertinent physical findings included a fever of 39.4°C, pulse of 120-130, and marked right upper quadrant tenderness with mild guarding but no rebound tenderness or palpable abdominal pulsatile mass. Laboratory analyses revealed elevated total bilirubin of 1.9 mg/dL (normal = 0.2-1.0 mg/dL), with direct bilirubin of 1.6 mg/dL (normal = 0.0-0.3 mg/dL), an elevated aspartate aminotransferase of 760 U/L (normal = 7-45 U/L), leukocytosis of 14,300 cells/μL (normal <11,000 cells/μL) and microcytic anemia with a hemoglobin of 10 g/dL (normal = 12-16 g/dL), hematocrit of 31% (normal = 38%-46%), and mean corpuscular volume of 78 fL (normal = 80-100 fL). ERCP, endoscopic retrograde cholangiopancreatography; MRCP, magnetic resonance cholangiopancreatography. Magnetic resonance cholangiopancreatography (MRCP) revealed a 1-cm dilated common bile duct tightly wrapped around a 5.8-cm abdominal aortic aneurysm with a thrombus (Fig. 1) causing extrahepatic bile duct compression and associated proximal bile duct dilatation without signs of choledocholithiasis (Fig. 2). The patient declined any surgery or other invasive procedures and was managed conservatively with antibiotics and pain control. Her symptoms initially improved, but she subsequently developed septic shock and died. Acute cholangitis is a bacterial infection typically superimposed on an obstruction of the biliary tree, usually caused by choledocholithiasis. The differential diagnosis also includes inflammatory biliary stricture caused by primary sclerosing cholangitis, obstructive tumors such as cholangiocarcinoma and ampullary neoplasm, biliary stenosis due to pancreatic pathology, iatrogenic endoscopic manipulation of the common bile duct and extrahepatic bile duct compression. There are a number of less common but important causes of cholangitis. Common bile duct stenosis has been caused by calcified, dissecting, and ruptured abdominal aortic aneurysms, abdominal aortic pseudoaneurysms and aneurysms of the celiac axis and hepatic artery. In previously reported similar cases, the prominent presenting symptom was jaundice, whereas others had abdominal pain, fever, and anorexia.1, 2 Another rare extraluminal source of common bile duct compression is portal hypertension causing dilated portal vein collaterals. In one series of eight cases of biliary obstruction secondary to portal cavernomas, the average time from portal cavernoma diagnosis—usually by ruptured esophageal varice—to biliary involvement was 8 years.3 In another study, the majority of patients with portal biliopathy who presented with acute cholangitis and were diagnosed by abdominal ultrasound with doppler and endoscopic retrograde cholangiopancreatography (ERCP).4 Elimination of biliary obstruction is critical for survival and includes endoscopic sphincterotomy and balloon endoscopic dilatation of the common bile duct as well as surgical decompression of the portal system with splenorenal shunting. This case demonstrates the importance of appropriate imaging such as MRCP to both accurately diagnose the cause of cholangitis and to guide definitive therapy to relieve biliary obstruction in patients with vascular and other anatomical anomalies. MRCP is an accurate and noninvasive tool for investigation of the pancreatico-biliary tree. It is more cost-effective than ERCP, has the ability to diagnose extrahepatic compression, and is far more sensitive than traditional ultrasound.5 Such cases should be initially treated with urgent biliary decompression and stent insertion for drainage. After resolution of infection, treatment options include repair of aneurysm by intraluminal patch aortoplasty and surgical exclusion of the aneurysm by ligation to address the underlying cause of the obstruction and prevent future complications.