Endoscopic management of common bile duct stump fistula after choledochojejunostomy: A case report

Abstract

BACKGROUND

Common bile duct (CBD) stump fistula after choledochojejunostomy is an exceedingly rare phenomenon. We report a unique case suffering from pancreaticobiliary reflux.

CASE SUMMARY

A 73-year-old man underwent Roux-en-Y end-to-side choledochojejunostomy for recurrent CBD stones. Fourteen days after surgery, the patient presented with high-amylase bile drainage (3192 U/L). Imaging revealed a CBD stump fistula. Endoscopic retrograde cholangiopancreatography showed pancreaticobiliary maljunction and sphincter of Oddi dysfunction. Therapeutic intervention, including pancreatic duct stenting and papillary clipping, successfully resolved the fistula.

CONCLUSION

In selected patients, endoscopic decompression may represent an effective management option for CBD stump fistulas associated with pancreaticobiliary reflux developed after choledochojejunostomy.

Key Words: Residual stump fistula; Choledochojejunostomy; Endoscopic retrograde cholangiopancreatography; Common bile duct; Case report

Core Tip: Common bile duct (CBD) stump fistula is an exceedingly rare complication of choledochojejunostomy. This case report suggests that pancreaticobiliary reflux, characterized by high drainage amylase, may contribute to CBD stump fistula, potentially via pancreaticobiliary maljunction or sphincter of Oddi dysfunction. Early recognition of this possible mechanism may be clinically important. Therapeutic endoscopic retrograde cholangiopancreatography, including pancreatic duct stenting and papillary intervention, effectively resolved the fistula in this patient by relieving reflux pressure. This minimally invasive strategy may represent a feasible management option and a potential alternative to surgical reoperation in selected cases.

INTRODUCTION

Choledochojejunostomy is a well-established surgical procedure for biliary reconstruction and decompression[1]. Common complications, such as anastomotic stricture and bile leakage, have been frequently documented in previous studies. Newly, the clinical significance of pancreaticobiliary reflux, which is often associated with pancreaticobiliary maljunction (PBM) or sphincter of Oddi dysfunction (SOD), is increasingly recognized as a factor involved in complex postoperative outcomes[2-4].

In contrast, common bile duct (CBD) stump fistula following choledochojejunostomy is an exceedingly rare and poorly characterized clinical entity. To assess the rarity and management strategies of this complication, a literature search was conducted in PubMed and Google Scholar up to March 2026 using the terms “common bile duct stump fistula”, “choledochojejunostomy”, and other related keywords. Only articles written in English were included in this study, and relevant case reports and case series were reviewed. The search revealed that only a few studies specifically addressed CBD stump fistula after choledochojejunostomy.

Herein, we present a 73-year-old man with both a CBD stump fistula and a choledochojejunostomy fistula, who was successfully managed via endoscopic intervention. This report highlights the potential diagnostic value of elevated amylase levels in the drainage fluid and explores the possible role of pancreaticobiliary reflux in fistula formation.

CASE PRESENTATION

Chief complaints

A 73-year-old man presented with an 8-month history of recurrent upper abdominal pain.

History of present illness

The patient experienced intermittent upper abdominal pain over the last 8 months before presentation. The pain was recurrent and was not associated with food intake. Pain frequency gradually increased over time. Initial ultrasonography at a local hospital suggested CBD stones.

History of past illness

The patient’s surgical history was significant for cholecystectomy. A CBD exploration was conducted in 1994, and a second CBD exploration for recurrent stones was performed in 2015. Over the last three years, he underwent three endoscopic retrograde cholangiopancreatography (ERCP) procedures for recurrent choledocholithiasis, including biliary stent placement 2 years before the current admission.

Personal and family history

The patient reported no history of smoking, alcohol consumption, pancreatitis, or hereditary hepatobiliary diseases.

Physical examination

On admission, physical examination revealed a soft abdomen with mild tenderness in the epigastric region. No rebound tenderness, guarding, or jaundice was observed.

Laboratory examinations

Liver function tests showed no significant hepatocellular injury. Laboratory test results were as follows: Aspartate aminotransferase: 19 U/L; alanine aminotransferase: 8 U/L; alkaline phosphatase: 83 U/L; gamma-glutamyl transferase: 49 U/L; total bilirubin: 19.8 µmol/L; and direct bilirubin: 7.6 µmol/L.

Imaging examinations

Computed tomography and magnetic resonance cholangiopancreatography indicated intrahepatic and extrahepatic bile duct stones with biliary dilation and atrophy of the left lateral hepatic segment (Figure 1).

Figure 1 Computed tomography and magnetic resonance imaging findings. A: Axial computed tomography image showing a large common bile duct (CBD) stone; B: Axial magnetic resonance imaging image confirming the presence of a large CBD stone; C: Magnetic resonance cholangiopancreatography indicating a large CBD stone with marked dilation of intrahepatic and extrahepatic bile ducts (left arrow) and dilation of the pancreatic duct (right arrow).

Postoperative course and diagnostic workup

The patient subsequently underwent laparoscopic left lateral segmentectomy combined with Roux-en-Y end-to-side choledochojejunostomy. The anastomosis was conducted using interrupted 4-0 absorbable sutures and a single-layer technique. On postoperative day 14, the patient developed abdominal pain and increased drainage from the operative site, with light-yellow fluid. The amylase level was markedly elevated in the drainage fluid (3192 U/L).

Fistulography via the subhepatic drainage tube showed opacification of the intrahepatic bile ducts and the jejunum, suggesting communication at the level of the choledochojejunostomy. In addition, sequential opacification of the distal CBD stump and the duodenum was observed, supporting the presence of a CBD stump fistula. Although precise anatomical localization is limited with this modality, together, imaging findings were consistent with the coexistence of both fistulas. Simultaneous opacification of the pancreatic duct revealed a long common channel measuring 17 mm (exceeding 15 mm as the diagnostic threshold), supporting the diagnosis of PBM and pancreaticobiliary reflux (Figure 2).

Figure 2 Fistulography and endoscopic retrograde cholangiopancreatography findings. A: Fistulography indicating a residual stump fistula of the common bile duct (middle arrow), a choledochojejunostomy fistula (upper arrow), and opacification of the pancreatic duct (lower arrow); B: Endoscopic retrograde cholangiopancreatography cholangiogram showing mild dilation of the pancreatic duct; C: Successful placement of a stent in the pancreatic duct.

Initial management comprised continuous irrigation and negative-pressure drainage through the indwelling drain, together with inhibition of pancreatic secretion and nutritional support.

ERCP was conducted six days later, which revealed a markedly enlarged papillary orifice (approximately 0.8 cm in diameter), suggesting SOD. No bile outflow was observed from the papilla. Pancreatography revealed mild pancreatic duct dilation, with a maximum diameter of 0.5 cm. Cholangiography revealed dilation of the distal CBD with a residual stump approximately 1 cm in length and contrast extravasation at the distal end (Figure 3).

Figure 3 Endoscopic findings and papillary intervention. A: Endoscopic images of a markedly enlarged papillary orifice; B: Endoscopic confirmation of successful stent placement in the pancreatic duct; C: Papillary orifice closed using a hemostatic clip.

FINAL DIAGNOSIS

The final diagnosis was residual CBD stump fistula with choledochojejunostomy fistula, accompanied by PBM.

TREATMENT

A pancreatic duct stent was placed during ERCP, and the papillary orifice was approximated using a hemostatic clip (Figure 3).

OUTCOME AND FOLLOW-UP

After ERCP, the drainage volume (approximately 210 mL/day before intervention) significantly decreased within two days, and abdominal pain resolved. Two weeks later, the patient was discharged with a stable condition. Follow-up confirmed spontaneous dislodgement of the pancreatic stent, with no recurrence of abdominal pain, cholangitis, or biliary leakage during the 1-year follow-up.

DISCUSSION

CBD stump fistula subsequent to choledochojejunostomy appears to be an extremely uncommon complication, although postoperative biliary leakage after biliary-enteric reconstruction has been reported in broader hepaticojejunostomy and choledochojejunostomy series. However, reports specifically describing CBD stump fistula after choledochojejunostomy remain very limited, and its underlying mechanisms have been poorly characterized[5-8].

Several notable features were observed in the present case, including recurrent CBD stones, multiple biliary interventions, and imaging findings suggestive of SOD and PBM. In addition to the CBD stump fistula, a concomitant choledochojejunostomy fistula existed and likely contributed to postoperative bile leakage. The exact mechanism underlying the development of the anastomotic fistula remains uncertain, but several factors, including local ischemia, technical tension at the anastomosis, and chronic inflammatory changes due to repeated biliary interventions, may have contributed to its pathogenesis. Although the exact volume contribution of each fistula could not be quantified, the coexistence of two fistulas may explain the relatively high postoperative drainage volume in this patient.

Both SOD and PBM may contribute to the reflux of pancreatic and duodenal contents into the biliary system[9,10]. This mechanism may explain the patient’s long history of recurrent bile duct stones and the opacification of the pancreatic duct in cholangiography[11-13]. In addition, the markedly elevated levels of amylase in the drainage fluid strongly suggest pancreaticobiliary reflux into the residual bile duct stump.

We hypothesized that continuous exposure of the stump to pancreatic juice may have impaired tissue healing. Activated pancreatic enzymes can damage the stump wall and interfere with its proper closure[14,15], particularly when absorbable sutures are used. In this case, the anastomosis was performed using 4-0 absorbable sutures in an interrupted single-layer fashion. However, pancreaticobiliary reflux should not be considered the sole reason for fistula formation in this patient.

Other factors may also have contributed. First, devascularization of the distal CBD stump during surgical dissection may have compromised local tissue perfusion and impaired the healing process. Second, technical factors during reconstruction, including stump closure quality or anastomotic tension, may have increased the risk of leakage. Third, chronic inflammatory scarring due to the patient’s prior biliary surgery and repeated ERCP procedures may have altered the local tissue condition and reduced tissue resilience. Finally, local postoperative inflammation or infection may also have been involved in the development of fistula[16,17]. Therefore, fistula formation in this case was likely multifactorial, with pancreaticobiliary reflux representing a possible contributing factor rather than a definitive cause.

Early recognition and timely intervention were critical in the management of this patient. Postoperatively, attention should be paid to the characteristics of drainage fluid. The presence of persistent drainage with a light yellow appearance should not be assumed to be a simple biliary leakage. Measurement of amylase level in the drainage fluid is particularly important, as a markedly elevated amylase level may suggest pancreaticobiliary reflux[11,18].

In case of abnormal drainage, fistulography through the drainage tube can help delineate the anatomy of the fistula and determine the involvement of the pancreatic duct. In our patient, opacification of the pancreatic duct provided an important diagnostic clue.

ERCP played both a diagnostic and therapeutic role[19]. Endoscopic pancreatic duct stenting reduced pancreatic ductal pressure and facilitated the preferential drainage of pancreatic juice into the duodenum, which was followed by a rapid decrease in drainage volume. Therefore, endoscopic decompression may be an effective and minimally invasive treatment option in selected patients. Supportive management, including adequate drainage, inhibition of pancreatic secretion, infection control, and nutritional support, is also essential[20].

For patients with a complete stump fistula who fail to respond to conservative and endoscopic management, surgical intervention remains a potential definitive treatment to restore the continuity and integrity of the bile duct and prevent recurrence[21]. However, reoperation is technically challenging and carries substantial risk; therefore, it should be considered cautiously.

The primary limitations of this case report were its single-case nature and the lack of long-term manometric data to quantify the reduction in reflux pressure after clipping. In addition, we could not establish a definitive causal relationship between pancreaticobiliary reflux and fistula formation in this patient. Due to the coexistence of a CBD stump fistula and a choledochojejunostomy fistula, it was challenging to explore the underlying mechanisms and determine the relative contribution of each lesion to postoperative drainage. Moreover, the technical success of papillary clipping in this case may not be generalizable to other patients, particularly those with different anatomical features or more severe PBM, in whom endoscopic treatment may be insufficient[22,23].

Nevertheless, endoscopic decompression may be considered in selected patients with CBD stump fistulas, particularly when pancreaticobiliary reflux is suspected, and reoperation brings substantial risk. In conclusion, early recognition of pancreatic juice involvement and timely endoscopic intervention may facilitate successful management in selected cases and potentially resolve the need for a high-risk reoperation.

CONCLUSION

Residual CBD stump fistula is an uncommon but clinically relevant complication of biliary-enteric reconstruction. In this patient, pancreaticobiliary reflux in the setting of PBM and SOD was considered a possible contributing factor, although a definitive causal relationship could not be established.

This case provides several clinical insights. Elevated amylase levels in postoperative drainage can serve as a useful clue to pancreaticobiliary involvement and may facilitate the early recognition of this unusual complication. In selected patients, endoscopic decompression, including pancreatic duct stenting, may represent a feasible minimally invasive management option.

Overall, this case should be deemed hypothesis-generating rather than practice-changing. Future studies are needed to clarify the underlying mechanisms and define the optimal management of this rare complication.

ACKNOWLEDGEMENTS

We wish to express our gratitude to the patient and his family.