Case of the Month

Radiological diagnosis:  

Impacted CBD stent fragment in the distal CBD.  

Management: 

ERCP guided stent fragment removal with rat mouth forceps was performed. There was symptomatic improvement.

Discussion:

Hindrance to the passage of conjugated bilirubin in the biliary tract leads to obstructive jaundice [1]. The CBD is the most common site of biliary obstruction [2]. Causes of obstructive jaundice include benign causes like choledocholithiasis and biliary stricture, and malignant causes like periampullary carcinoma and carcinoma of the head of the pancreas.

Pre-operative ERCP for CBD stone clearance followed by laparoscopic cholecystectomy is preferred in managing cholelithiasis with choledocholithiasis. This approach ensures a clear bile duct without distal obstruction, reducing the risk of postoperative bile leaks and the need for additional interventions [3]. In cases where stones are refractory to endoscopic retrieval, a biliary stent is placed as a temporary measure to maintain biliary drainage and prevent stone impaction, while awaiting definitive treatment [4]. After complete clearance, the biliary stent is retrieved to reduce common complications like stent misplacement, displacement, hemorrhage, obstruction, perforation, and infection. The complication rate is higher in patients with longstanding stents [7]. However, in this case, the CBD stent was retrieved in fragments, as the stent was placed five years ago. It is important to ensure complete removal when the stent is broken, as a residual fragment can also cause cholestasis. 

Cholestasis is the main pathology behind obstructive jaundice, which clinically presents as pruritus, pale-colored stools, xanthomas, and abdominal pain [5]. Routine biochemical workup includes Total and direct bilirubin levels, Serum Alanine Transaminase levels, and an elevated level of Direct bilirubin, which is specific for cholestasis.

This patient was asymptomatic and became symptomatic a few days after stent removal with elevated levels of total and direct bilirubin.

Pre- and post-procedure abdominal radiographs ensure clearance of all fragments when CBD stents are removed in fragments. Symptomatic patients with abnormal foreign bodies in the juxtahepatic region should be screened. If screening transabdominal ultrasonography shows a dilated CBD with a diameter of more than 6 to 7 mm [6], the entire CBD from its origin to the duodenum should be screened for calculus, mass, or other pathology causing obstruction. In this case, an echogenic fragment of the stent is seen in the distal CBD near the pancreatic head.

Contrast-enhanced CT scans are accurate in localising the level of obstruction and the etiology of cholestasis based on the pattern of CBD cutoff [8]. 

Conclusion-

The rate of complications associated with the CBD stent increases with the duration of stent placement.

A chronically placed stent, when removed in pieces, requires simple investigations such as serial radiographs obtained pre- and post-procedure to assure complete evacuation of the CBD.