Benign Biliary Stricture

Benign biliary stricture is a non-malignant narrowing of the bile duct that causes cholestasis, cholangitis and secondary biliary cirrhosis if untreated.

• Causes: postoperative bile duct injury (about 80 percent, mostly after cholecystectomy), chronic pancreatitis (distal common bile duct), primary sclerosing cholangitis, IgG4 related sclerosing cholangitis, Mirizzi syndrome and impacted stones, ischaemic cholangiopathy (after liver transplant, hepatic artery occlusion, chemotherapy), radiotherapy, trauma, recurrent pyogenic cholangitis (hepatolithiasis), parasites (Ascaris, Clonorchis, Fasciola), tuberculosis, HIV cholangiopathy, portal biliopathy (portal vein thrombosis) and sphincter of Oddi stenosis.
• Lesions may develop months to years after the initial injury.

Intermittent or progressive jaundice, pruritus, dark urine, right upper quadrant pain, recurrent fever and rigors (cholangitis), fatigue; some are detected by raised alkaline phosphatase alone.

• Chronic pancreatitis strictures cause jaundice with abdominal pain and weight loss; primary sclerosing cholangitis presents with fatigue, itch and inflammatory bowel disease; IgG4 disease presents with jaundice, autoimmune pancreatitis, salivary gland swelling and retroperitoneal fibrosis.
• Differential diagnosis: malignant stricture (cholangiocarcinoma, pancreatic cancer), choledocholithiasis, hepatitis, primary biliary cholangitis, drug-induced cholestasis, extrinsic compression by nodes or pseudocyst.
• Complications: cholangitis, hepatolithiasis, hepatic abscess, secondary biliary cirrhosis, portal hypertension, cholangiocarcinoma (in primary sclerosing cholangitis), recurrent stricture, bile duct stones and sepsis.

Cholestatic liver profile, bilirubin, INR, full blood count, CRP; IgG4 level; antimitochondrial antibody and ANA; HIV test.

• Magnetic resonance cholangiopancreatography defines the site, length and number of strictures; CT for pancreatic disease, nodes or collections.
• Endoscopic ultrasound and endoscopic retrograde cholangiopancreatography with brush cytology and intraductal biopsy to exclude malignancy (a benign result does not exclude cancer; follow-up for 6 to 12 months).
• Features favouring a benign stricture: short smooth narrowing, history of surgery or pancreatitis, stable course; features favouring malignancy: long irregular stricture, mass, wall thickness over 3 mm, rising CA 19-9, weight loss.

Supportive: nutrition, fat soluble vitamins (vitamin K 10 mg IV for coagulopathy), treatment of pruritus (cholestyramine 4 g up to three times daily, rifampicin 150 to 300 mg twice daily), analgesia.

Pharmacological

• Cholangitis: piperacillin-tazobactam 4.5 g IV every 6 to 8 hours or ceftriaxone 2 g IV daily plus metronidazole 500 mg IV every 8 hours for 5 to 7 days after drainage.
• IgG4 related stricture: prednisolone 0.6 mg/kg (30 to 40 mg) daily for 4 weeks, taper by 5 mg every 2 weeks to stop within 3 months; azathioprine 2 mg/kg daily or rituximab 1 g on days 1 and 15 for relapse.
• Primary sclerosing cholangitis: ursodeoxycholic acid 13 to 15 mg/kg/day has uncertain benefit; high doses above 28 mg/kg/day cause harm; treat dominant strictures.
• Parasites: praziquantel 25 mg/kg three times daily for 2 days (clonorchiasis), albendazole 400 mg single dose (ascariasis), triclabendazole 10 mg/kg (fasciolosis).
• HIV cholangiopathy: antiretroviral therapy; treat cryptosporidium with nitazoxanide 500 mg twice daily for 3 days.

Procedures

• Endoscopic dilation with progressive placement of multiple plastic stents (increase the number every 3 months for 12 months; success in 80 to 90 percent), or a fully covered self-expanding metal stent for 6 to 12 months.
• Percutaneous transhepatic balloon dilation and drainage when endoscopy cannot reach the stricture.
• Surgery: Roux-en-Y hepaticojejunostomy (success 80 to 90 percent) for complete or complex strictures, failed endoscopic therapy, or chronic pancreatitis stricture; liver resection for unilateral atrophy and hepatolithiasis; transplant for end stage secondary biliary cirrhosis.

Special groups: chronic pancreatitis (covered metal stent; treat pain and alcohol use), liver transplant recipients (balloon dilation with stents), children (biliary atresia needs early surgery).

Red flags: cholangitis, hepatic abscess, failure of endoscopic therapy, biliary cirrhosis, suspicion of malignancy.

Follow-up: liver profile every 3 months during stenting and for 2 years after; imaging for recurrence; surveillance for cholangiocarcinoma in primary sclerosing cholangitis.