Charles E. Lohr, MD
PGY-4 Resident of Radiology

Hoang Trang, DO
PGY-4 Resident of Radiology

Surendra Bansal, MD
Professor of Radiology
University of Pittsburgh
Medical Center-Mercy
Pittsburgh, PA

ABSTRACT
Introduction: Biliary stents are commonly used in the palliative treatment of obstructive jaundice from pancreatic neoplasms. Complications associated with biliary stents include bleeding, infection, obstruction, and migration, which can occur any time after placement. Although stent fractures are rare, they may present early or late after placement and can be identified using radiographic imaging.

Results and discussion: The authors describe the case of an elderly man who presented with jaundice after his biliary stent fractured. A fragment migrated to his bowel and caused obstruction, requiring surgical intervention. They highlight their patient's radiographic findings and discuss complications associated with biliary stents used to correct malignant obstruction.

Conclusion: Prophylactic measures are crucial in preventing complications associated with biliary stents and include frequent physical examinations, laboratory screenings, and radiographic evaluations. The patency period of biliary stents is generally short, and stent replacement may be warranted for patients whose survival exceeds 5 months.

Figure 1—Contrast-enhanced CT scan showing intrahepatic biliary ductal dilatation (A). More inferiorly, a 3-cm neoplasm is visible in the head of the pancreas (B).

Biliary stents are advocated for the palliative treatment of obstructive jaundice from pancreatic neoplasms. The majority of biliary stents remain patent for only 5 months, and ongoing follow-up is recommended to evaluate stent function. This improves the likelihood of detecting complications that may require medical therapy, stent replacement, or surgery.

We report the case of an 83-year-old man who presented with hematemesis and abdominal distention 4 months after stent placement to relieve biliary obstruction caused by a neoplasm in the pancreatic head. Radiographic imaging confirmed a fractured stent and showed distal small bowel obstruction due to the stent fragment. The stent fragment was removed surgically, resolving the patient's symptoms.

CASE REPORT

An 83-year-old man presented to the hospital because of jaundice. Computed tomography (CT) scanning demonstrated a 3-cm mass in the head of the pancreas, along with pancreatic and biliary ductal dilatation (Figure 1). Pulmonary metastases were also observed. The patient's medical history was significant for rectal cancer, which was diagnosed 14 years earlier and for which he had undergone anterior resection and colostomy.

Figure 2—Radiograph showing the biliary stent within the common bile duct. The stent fragment is located in the mid-pelvis, causing a partial small bowel obstruction. A nasogastric tube was placed, and a vena caval filter and colostomy are visible in the left lower quadrant.

Biliary endoprosthesis was attempted with endoscopy but was unsuccessful due to stricture of the common bile duct. Percutaneous placement of a metallic, internal stent, which was 65-mm long and 10-mm in diameter, resolved the biliary obstruction.

The patient returned to the hospital 4 months later, after experiencing 1 day of hematemesis and abdominal distension. Abdominal radiography showed the common bile duct stent in position and a metallic density within the pelvis (Figure 2). A small bowel follow-through study demonstrated dilated bowel loops beginning at the jejunum and terminating at the distal ileum where the metallic fragment was located (Figure 3). Abdominal and pelvic CT scanning showed dilated loops of small bowel with a transition point at the site of the stent fragment, within the terminal ileum (Figure 4). During exploratory laparotomy, the stent fragment was palpable within the bowel lumen. This segment of the distal ileum was resected, and primary anastomosis was performed by side-to-side functional end-to-end anastomosis (Figure 5). The proximal portion of the stent remained in satisfactory position and was left in place. Postoperatively, the patient received routine antibiotics and pain medications, and his recovery was uneventful.

DISCUSSION

Biliary stenting is well-established as a temporary or definitive treatment for biliary obstruction resulting from benign or malignant lesions.¹ Plastic and metallic stents are available, but metallic stents are used most often for providing palliation in patients who have malignant disease and are not surgical candidates.

Complications related to biliary stenting are categorized as early or late: morbidity or mortality that occurs within the first 30 days following placement is termed early, whereas complications that arise after 30 days are classified as late.² Early complications generally include infection, bleeding, and stent instability in technically difficult cases. Late complications commonly involve obstruction, migration, and tumor overgrowth. Stent fracture is a rare complication of biliary endoprosthesis and can occur early or late; it has been observed anywhere from 24 hours to 4 years after placement.³

Our case illustrates the importance of recognizing possible complications associated with biliary stents. Prophylactic measures have been suggested to prevent complications associated with stents that were placed to correct malignant obstruction. These include recommending that patients undergo frequent physical examinations, laboratory screenings, and serial abdominal radiographs to check for biliary obstruction and replacing stents in patients whose survival is prolonged. It may be prudent to conduct follow-up examinations as frequently as every 3 months.

Biliary stent fractures

Figure 3—Small bowel follow-through showing dilatation of small bowel loops beginning at the jejunum and terminating at the distal ileum where the fractured stent fragment is located. There is minimal reflux of barium from the duodenum into the common bile duct.

Stent fractures have been attributed to a variety of factors, including the type of stent used, whether it has been in place longer than its expected patency period, the presence of malignant stricture, and placement and retrieval procedures employed.⁴ Our patient's stent fracture likely resulted from the continuous anatomic stress of bending. He did not undergo any interventions following initial stent placement, and we observed no change in the size of the pancreatic head mass that would support fracture secondary to tumor growth.

Fractures usually occur at the level of the anchoring flap, and the fragments typically remain within the biliary tree. Most patients present with obstructive jaundice or cholangitis. Clinical findings suggestive of biliary stent fracture include jaundice, abdominal pain, elevated bilirubin levels, and abnormal pancreatic enzymes. These findings may be secondary to biliary obstruction.

Radiography

Radiographic examination is recommended when there is suspicion that a biliary stent has fractured and has not been eliminated completely. If the stent has fractured, a radiograph will show a change in size from the time of placement. Any stent fragment will likely be identified more distally within the abdomen or pelvis. Further imaging with cholangiography or CT cross-sectional imaging may be warranted to evaluate the patient for any possible complications associated with the stent fracture, such as biliary obstruction. In the case of a migrated fragment, cholangiography or CT cross-sectional imaging should be considered to evaluate the patient for infection, hematoma, or, as in our case, bowel obstruction.

Biliary stent migrating to bowel

Fracture of a biliary stent with the inferior fragment migrating to the bowel has been documented previously.^5,6 Peck and Wattam report the case of an 81-year-old patient who had stricture of the mid-lower common bile duct associated with cholangiocarcinoma; the patient presented with obstructive jaundice 5 weeks after stent placement and was found to have a stent fracture.⁵ Mallat and associates describe the case of an 83-year-old patient who required a biliary stent for a pancreatic malignancy; this patient's stent fracture was detected secondary to isolated fever 3 months after placement.⁶ In both cases, the stent was removed without complications. To our knowledge, ours is the first report of a biliary stent fracture in which migration of a stent fragment resulted in bowel obstruction and required surgical intervention.

Treatment

Endoscopic retrieval is the preferred treatment for stents that have fractured within the biliary system. It is possible that an endoscopic approach may not retrieve the stent. If the stent remains patent, it may be left in position. If the fractured stent cannot be retrieved and is causing obstruction, placement of another stent may be attempted endoscopically or percutaneously. If these approaches are unsuccessful, surgery may be considered.

CONCLUSION

Biliary stents are commonly used as palliative treatment for obstructive jaundice due to pancreatic neoplasms. A longer survival period increases the risk that the patient will experience complications, including stent fracture. Prophylactic measures are recommended for such patients to prevent complications that could require surgical intervention. Close follow-up using radiographs, and if there are complications with the stent, cholangiography and CT scanning, may be helpful for evaluating these patients.

Figure 4—Unenhanced CT scan showing a metallic stent fragment within the lumen of the distal ileum.	Figure 5—Intraoperative specimen showing the resected ileum with mucosal ulceration and a 2.2-cm fractured stent prosthesis.

References

1. Smilanich RP, Hafner GH. Complications of biliary stents in obstructive pancreatic malignancies. A case report and review. Dig Dis Sci. 1994;39(12):2645-2649.
2. Mueller PR, Ferrucci JT Jr, Teplick SK, et al. Biliary stent endoprosthesis: analysis of complications in 113 patients. Radiology. 1985;156(3):637-639.
3. Geschwind JF, Dagli MS, Vogel-Claussen J, et al. Percutaneous removal of a fractured endostent remnant from the portal vein. Cardiovasc Intervent Radiol. 2002;25(2):152-154.
4. Diller R, Senninger N, Kautz G, et al. Stent migration necessitating surgical intervention. Surg Endosc. 2003;17(11):1803-1807.
5. Peck R, Wattam J. Fracture of Memotherm metallic stents in the biliary tract. Cardiovasc Intervent Radiol. 2000;23(1):55-56.
6. Mallat A, Saint-Marc Girardin MF, Meduri B, et al. Fracture of biliary endoprosthesis after endoscopic drainage for malignant biliary obstruction. Report of two cases. Endoscopy. 1986;18(6):243-244.