Endoscopic Management of Recurrent Biliary Sepsis Associated with Prolonged Biliary Stent Exposure into the Duodenal Bulb and Concurrent Duodenal Obstruction in Advanced Pancreatic Cancer

A 69-year-old woman with pancreatic adenocarcinoma was referred because of recurrent fever and biliary sepsis. She had been diagnosed with stage III pancreatic head cancer (Fig. 1A, B) in July 2023 and underwent endoscopic retrograde cholangiopancreatography (ERCP) with the placement of a fully covered, self-expandable metal stent (FC-SEMS) for malignant biliary obstruction (Fig. 1C, D). Despite palliative chemotherapy, the disease progressed to stage IV by December 2024. Since late 2024, she experienced repeated episodes of fever, leukocytosis, and hyperbilirubinemia requiring hospitalization, consistent with recurrent obstructive cholangitis and biliary sepsis. Physical examination revealed mild right upper quadrant tenderness. Laboratory tests showed an elevated white blood cell count and total bilirubin level. Contrast-enhanced computed tomography (CT) demonstrated tumor progression with near-complete obstruction of the second portion of the duodenum and dilatation of the biliary tree (Fig. 2A, B). Esophagogastroduodenoscopy revealed severe tumor-related duodenal stenosis and partial exposure of the shaft of the FC-SEMS into the duodenal bulb (Fig. 2C, D). Because marked duodenal obstruction presented concurrently, the recurrent sepsis was interpreted as resulting from the combined effects of impaired antegrade biliary drainage, increased intraduodenal pressure, and duodenobiliary reflux through the exposed and partially occluded stent, rather than from stent exposure alone.

FIG. 1. (A, B) Initial contrast-enhanced computed tomography (CT) images showing a pancreatic head mass with malignant biliary obstruction and upstream biliary dilatation. (C, D) Endoscopic retrograde cholangiopancreatography (ERCP) demonstrating distal biliary stricture and deployment of a fully covered self-expandable metal stent (FC-SEMS) across the obstruction.

FIG. 2. (A, B) Follow-up CT images showing disease progression with near-complete obstruction of the second portion of the duodenum and biliary dilatation despite the indwelling FC-SEMS. (C, D) Esophagogastroduodenoscopy showing severe tumor-related duodenal stenosis and partial exposure of the FC-SEMS shaft into the duodenal bulb. Arrows highlight the exposed stent, which served as a conduit for duodenobiliary reflux in the setting of impaired antegrade drainage. (E, F) Argon plasma coagulation (APC) applied to remove obstructing tissue and debris and to recanalize the occluded FC-SEMS without placement of an additional biliary stent. (G, H) Deployment of a duodenal self-expandable metal stent (SEMS) across the malignant duodenal obstruction to restore alimentary passage, decompress the duodenum, and reduce reflux toward the biliary stent.

Endoscopic re-intervention was performed. A stent-instent approach or placement of an additional plastic stent was considered; however, severe tumor-related duodenal deformity and the intraluminally exposed FC-SEMS made stable access to the biliary axis and coaxial guidewire manipulation technically unfavorable. Additional biliary stenting also had the potential to further crowd the narrowed duodenal lumen without correcting the gastric outlet obstruction. Argon plasma coagulation (APC) was therefore selected because the exposed stent was directly accessible endoscopically and APC allowed non-contact ablation of obstructing tissue and debris with recanalization of the occluded FC-SEMS, without implanting another biliary device (Fig. 2E, F). A duodenal self-expandable metal stent (SEMS) was subsequently placed to relieve gastric outlet obstruction, reduce intraduodenal pressure, restore antegrade passage, and separate the exposed biliary stent from the food stream within the duodenal lumen (Fig. 2G, H). After treatment, fever resolved and inflammatory markers and bilirubin levels improved. The patient resumed oral intake and was discharged in stable condition with continued palliative care.

Endoscopic biliary stenting is a standard palliative treatment for malignant biliary obstruction.1,2 FC-SEMSs are useful because the covering membrane reduces tumor ingrowth; however, they are associated with a broad spectrum of early and delayed complications, including migration, sludge or food impaction, stent occlusion, tumor overgrowth at the stent ends, pancreatitis or cholecystitis, duodenal erosion, stent exposure, fistula-like choledochoduodenal communication, and reflux cholangitis.3 Partial stent exposure or a choledochoduodenal communication may be encountered in clinical practice and does not invariably cause sepsis by itself. The distinctive feature of this case is recurrent biliary sepsis after prolonged indwelling FC-SEMS placement in combination with a severe malignant duodenal obstruction, which made the exposed stent clinically relevant as part of a combined reflux-and-obstruction mechanism.

The pathophysiology in this patient should therefore be interpreted as multifactorial rather than as the consequence of stent exposure alone. Tumor progression produced near-complete duodenal obstruction, which likely increased intraduodenal pressure, promoted food retention and bacterial overgrowth, and impaired antegrade bile flow through the distal biliary stent. Under these conditions, the exposed and partially occluded FC-SEMS could function as a conduit for retrograde duodenobiliary reflux, resulting in repeated cholangitis and biliary sepsis. This mechanism also explains why durable clinical improvement occurred only after both components were addressed: recanalization of the biliary stent and relief of duodenal obstruction.4,5

Endoscopic re-intervention is generally the preferred management strategy for malignant biliary stent dysfunction. Established options include balloon cleaning, placement of a plastic stent through the existing metal stent, and metal stent-in-stent placement.5 In the present case, these options were considered, but severe duodenal stenosis, distorted anatomy, and the exposed intraluminal segment of the FC-SEMS limited stable endoscopic access and were expected to make guidewire passage and coaxial stent deployment difficult. Moreover, additional biliary stenting alone would not have corrected the high-pressure duodenal segment that probably drove reflux. APC was chosen because it provided immediate, localized, non-contact ablation of obstructing tissue and debris within the exposed stent and restored biliary patency without adding another device to the narrowed duodenal lumen. Duodenal SEMS placement was then performed to treat gastric outlet obstruction and to reduce the reflux-promoting pressure gradient. This case emphasizes that recurrent cholangitis or biliary sepsis in patients with long-term FC-SEMSs should prompt careful endoscopic evaluation for both biliary stent dysfunction and concomitant duodenal obstruction, even when cross-sectional imaging alone does not fully explain the recurrent infection. Early recognition of this combined mechanism may facilitate timely endoscopic intervention and prevent recurrent biliary sepsis.