Spontaneous choledochoduodenal fistula following complete common bile duct transection from penetrating abdominal trauma: an unexpected non-operative resolution

Abstract

Background

Traumatic injuries to the extrahepatic biliary tree are extremely rare, accounting for less than 0.5% of abdominal traumas. They are often associated with severe concomitant vascular and hepatic lesions, and their diagnosis may be delayed due to overshadowing hemorrhagic injuries. Management strategies depend on the patient’s hemodynamic status, ranging from primary repair in stable patients to staged damage-control procedures in unstable situations.

Case presentation

We report the case of a 29-year-old male with no medical history who presented with a thoraco-abdominal stab wound at the right seventh intercostal space. CT scan revealed a grade V hepatic injury extending to the hepatic hilum, with active bleeding from a portal vein branch and suspected common bile duct (CBD) injury. Emergency laparotomy showed a transfixing liver wound involving segments V and VII, complete transection of the CBD, and a partial portal vein injury. Hemorrhage control was achieved with Pringle’s maneuver, portal vein repair, cholecystectomy, transcystic drainage, and hepatic packing. After stabilization and second-look laparotomy 48 h later, the patient developed a subcapsular biloma that was drained percutaneously. Over the following weeks, biliary drainage progressively decreased. MRCP and endoscopic evaluation at two months revealed a spontaneous choledochoduodenal fistula allowing physiological internal drainage. In the absence of biliary dilatation or hepatic dysfunction, definitive bilio-enteric reconstruction was not performed. At one-year follow-up, the patient remains asymptomatic with normal liver function.

Discussion

This case highlights several key aspects in the management of penetrating biliary trauma: the diagnostic limitations of imaging in the acute setting, the role of staged surgery in unstable patients, and the potential for conservative management when spontaneous internal biliary drainage develops. Spontaneous choledochoduodenal fistula formation following traumatic CBD transection is exceptionally rare, with only isolated reports in the literature.

Conclusion

A tailored, staged approach is crucial in managing complex traumatic biliary injuries. In some fortunate situations, spontaneous choledochoduodenal fistulization can provide effective biliary drainage and obviate the need for complex reconstructive surgery, provided close follow-up is ensured.

Introduction

Traumatic injuries to the extrahepatic bile ducts are exceptionally rare, representing less than 0.1% of all trauma patients and 1 to 3% of abdominal trauma [1]. When they do occur, The traumatic injuries to the extra hepatic billiary ducts occur more often after penetrating abdominal trauma (80% of cases), and isolated common bile duct (CBD) transection is exceedingly uncommon [2]. In most cases, biliary injuries are diagnosed intraoperatively, frequently in the context of associated visceral or vascular lesions, and their management remains a major surgical challenge.

Unlike iatrogenic bile duct injuries, which are typically encountered after laparoscopic cholecystectomy, traumatic bile duct lesions are often under-recognized at the initial evaluation [3]. Delayed diagnosis can lead to significant morbidity, including persistent bile leaks, sepsis, biliary peritonitis, or secondary biliary cirrhosis. Spontaneous biliodigestive fistulas are an uncommon phenomenon, most often associated with gallstone disease or peptic ulcer disease [4]. Their occurrence following trauma is exceptional, with only isolated cases reported in the literature [5].

We present the case of a young man who sustained a penetrating thoraco-abdominal injury leading to complete transection of the CBD. Remarkably, the patient evolved toward the formation of a spontaneous choledochoduodenal fistula, which provided an effective internal biliary drainage, avoiding the need for surgical reconstruction. This case underlines both the rarity of traumatic CBD injuries and the uniqueness of spontaneous fistulization as a natural solution to biliary continuity.

This work is reported in line with the scare criteria [6].

Case presentation

A 29-year-old male with no significant past medical history presented to the emergency department with a penetrating thoraco-abdominal knife wound at the level of the right 7th intercostal space. On examination, there was a 2 cm bleeding wound at the right posterior 7th intercostal space. The patient complained of right hypochondrial abdominal pain associated with distension and vomiting. Physical examination revealed tenderness of the right upper quadrant with abdominal distension. A FAST ultrasound examination was not performed due to lack of availability in the emergency setting. Initial laboratory investigations, including liver function tests, were within normal limits. The patient was hemodynamically stable, with a blood pressure of 110/60 mmHg, heart rate of 80 bpm, and oxygen saturation of 99%. Laboratory investigations revealed a hemoglobin level of 10.2 g/dL, with normal renal and electrolyte parameters.

Chest X-ray showed a right pleural effusion with an associated pneumothorax. A thoraco-abdominal CT scan revealed a laceration of hepatic segment V with arterial contrast extravasation, active intrahepatic bleeding from a branch of the middle hepatic vein, and extension of the laceration to the hepatic hilum. There was also a hemicircumferential injury of the portal vein trunk upstream of its bifurcation, with active bleeding and a hematoma in the lesser sac. Suspicion was raised for injury to the common bile duct (CBD) and pancreatic isthmus. The patient was rapidly resuscitated with blood transfusions and taken to the operating room for emergency laparotomy.

Through a midline incision, a large hemoperitoneum was found, along with a transfixing liver injury involving segments V and VII extending to the hepatic hilum and the gallbladder. The injury caused a choledochal-level transection of the common bile duct and a hemicircumferential laceration of the portal vein trunk. There was also a 3 cm diaphragmatic tear. A Pringle maneuver was performed to reduce bleeding, followed by peritoneal lavage. The portal vein injury was repaired using continuous 5 − 0 Prolene sutures. A cholecystectomy was performed. The biliary injury appeared consistent with complete transection, as two non-contiguous ductal ends were identified, with bile leakage from the proximal segment and retraction of the distal duct toward the pancreatic head, without visible continuity. However, given the inflammatory and traumatic context, absolute exclusion of a partial injury was not possible. The CBD was intubated with a 6 Fr trans-cystic drain, The distal bile duct stump was left undisturbed because of retraction and unfavorable local conditions, in keeping with damage-control principles. Persistent bleeding from the transfixing hepatic laceration, along with bile leakage, necessitated hepatic packing using five laparotomy pads. A chest tube was inserted through the 10th intercostal space, and the diaphragmatic injury was closed. Chest tube insertion was intentionally deferred until surgical exploration because of an associated diaphragmatic injury; a controlled intraoperative placement was preferred to minimize the risk of complications.

Postoperatively, the patient achieved hemodynamic and respiratory stabilization, with transfusion allowing stabilization of hemoglobin at 11 g/dL prior to the planned relaparotomy.

The patient underwent planned re-laparotomy 48 h later. There were only a small amount of serous fluid and no active bleeding. The hepatic packs were removed; the biliary injury was reassessed. However, the local operative conditions were unfavourable for definitive biliary reconstruction. The hepatoduodenal ligament and porta hepatis were characterized by severe inflammation and edema, with marked tissue friability. Importantly, the biliary injury was located in close proximity to a recent portal vein repair, and further dissection was judged to carry a significant risk of disrupting the vascular repair and provoking uncontrolled hemorrhage.

In this context, attempting a primary repair or a T-tube reconstruction, as well as further aggressive anatomical dissection, was considered unsafe. The decision was therefore made to maintain a damage-control strategy with external biliary drainage and deferred reconstruction. Two subhepatic Salem drains were placed. Initially, the subhepatic drains returned bile-stained fluid, which progressively became serous. The trans-cystic drain had a bile output ranging between 400 and 700 mL/day. The patient was extubated on postoperative day (POD) 4 and transitioned to non-invasive ventilation.

On POD 10, the patient developed fever. Imaging revealed a subcapsular biloma in hepatic segment V, which was drained under CT guidance (Fig. 1). One liter of bile was aspirated initially, followed by daily drainage of 300–400 mL. Over time, the subhepatic drains ceased output, and the trans-cystic drain output decreased to 200 mL/day. Cholangiography revealed a segmental bile leak originating from segment V, likely responsible for the persistent subhepatic collection, with no opacification of the distal bile duct or duodenum compatible with intraoperative findings (Fig. 2).

Fig. 1.

a : CT Scan images showing the biloma (yellow arrow) b: the drain placed with CT guidance (blue arrow)

Fig. 2.

Cholangiography revealed a segmental bile leak originating from segment V

By POD 20, both the trans-cystic and subhepatic drains had stopped draining and the subhepatic drains were removed. The percutaneous drain continued to return approximately 200 mL/day. Follow-up CT imaging demonstrated near-complete regression of the subcapsular hepatic collection (Fig. 3). The CBD was mildly dilated to 10 mm with a “cup-like” tapering at its distal end. The trans-cystic drain was no longer in place and showed no biliary output and was therefore initially clamped to assess tolerance. After four days of successful clamping without clinical or biochemical deterioration, the drain was removed.

Fig. 3.

CT scan image showing the complete regression of the biloma

Liver function tests were slightly elevated during the early postoperative period and progressively normalized by postoperative day 10. Following exclusion of external biliary drainage during drain clamping, a transient mild elevation of liver enzymes was observed for approximately five days, after which values returned to normal, without associated clinical signs of biliary obstruction or infection.

During the initial postoperative period, the patient received parenteral nutrition with high-calorie support and bicarbonate supplementation to compensate for metabolic losses related to high-output external biliary drainage. After recovery of gastrointestinal function, nutritional management was transitioned to an oral high-calorie diet, with continued sodium bicarbonate supplementation to offset ongoing bile loss.

The patient was discharged with the percutaneous drain in situ and scheduled for biliary reconstruction (hepaticojejunostomy) after 3 months, once ductal dilation was achieved. Over subsequent weeks, percutaneous drain output gradually decreased to 50 mL/day, before accidental dislodgement occurred. Ultrasound demonstrated no residual collection, no intra-abdominal fluid, and a CBD measuring 8 mm. The patient remained anicteric. At 2 months, follow-up ultrasound showed similar findings with normal liver function tests.

Magnetic resonance cholangiopancreatography (MRCP) revealed a small communication between the CBD and the duodenum (Fig. 4). Upper endoscopy confirmed the presence of bile in the duodenal lumen, and side-viewing duodenoscopy demonstrated a choledochoduodenal fistula located away from the papilla (Fig. 5). The diagnosis of a spontaneous choledochoduodenal fistula was established. Given the absence of cholestasis and the presence of effective spontaneous biliary drainage, the planned hepaticojejunostomy was canceled, and the patient was managed conservatively.

Fig. 4.

Magnetic resonance cholangiopancreatography (MRCP) revealed a small communication between the CBD and the duodenum (red arrow)

Fig. 5.

Upper endoscopy showing a choledochoduodenal fistula located away from the papilla (red arrow) and bile in the duodenum (green arrow)

At one-year follow-up, the patient remained asymptomatic with normal liver function tests and no evidence of biliary obstruction.

Discussion

Traumatic injuries to the extrahepatic biliary tract are rare, with a reported incidence of 1–3% of all abdominal trauma cases [1]. Hepatic trauma itself is relatively common, but the majority are blunt injuries involving the parenchyma rather than the biliary tree [7]. Penetrating trauma, although less frequent, is typically associated with more severe and complex lesions, often involving simultaneous damage to vascular and biliary structures(8). Although traumatic injuries of the common bile duct have been previously reported, cases evolving toward spontaneous internal biliary drainage without surgical reconstruction remain exceedingly rare.

In hemodynamically stable patients, the management of hepatic trauma has shifted toward a conservative, non-operative approach supported by advances in imaging and interventional radiology, with excellent reported outcomes [8, 9]. Operative intervention is generally reserved for unstable patients or those with major vascular injuries.

Early diagnosis of extrahepatic biliary injuries remains challenging. Clinical signs may be masked by associated hemorrhage or visceral trauma, and initial laboratory values are often unremarkable. Multidetector CT scan is the primary diagnostic modality in stable trauma patients, but its sensitivity for bile duct injuries is limited. Indirect signs such as unexplained perihepatic fluid collections may raise suspicion, and the presence of associated vascular injury should heighten concern for concomitant biliary damage, given the close anatomic relationship at the hepatic hilum [10]. Moreover, bile duct injuries can sometimes be overlooked even during emergency laparotomy, particularly in the context of hemodynamic instability, active bleeding, or multiple injuries [3]. A high index of suspicion and meticulous intraoperative assessment are therefore essential.

The surgical strategy is guided primarily by the patient’s physiological status and the injury pattern. In stable patients with isolated bile duct injury, primary repair over a T-tube or immediate biliary-enteric reconstruction can be safely performed in experienced hands [11, 12]. Conversely, in unstable patients or those with complex associated injuries, a damage control approach is preferred. This focuses on hemorrhage control, external biliary drainage, and physiological stabilization, with definitive biliary reconstruction deferred [2]. A planned second-look laparotomy after stabilization offers an opportunity to perform a repair if local conditions are more favorable, avoiding the morbidity associated with attempting complex reconstruction in a hostile, inflamed operative field.

Postoperative bile leakage is a common consequence of such injuries and requires vigilant monitoring. Imaging and percutaneous drainage play a central role in controlling bilomas and preventing sepsis [13]. In the absence of spontaneous biliary continuity, the standard definitive treatment for complete transection is a delayed biliary-enteric anastomosis, typically a Roux-en-Y hepaticojejunostomy, performed after at least 3 months or once the bile ducts have become adequately dilated and local inflammation has resolved. This timing facilitates a tension-free, well-vascularized anastomosis and minimizes the risk of postoperative stricture [11].

A remarkable feature of this case is the development of a spontaneous choledochoduodenal fistula, which ultimately restored physiological bile flow and obviated the need for surgical reconstruction. Spontaneous internal biliary fistulization is an exceptional phenomenon in the post-traumatic setting. When it occurs, it is more frequently related to chronic inflammatory processes such as gallstone disease, or peptic ulcer [4]. In our patient, prolonged external biliary drainage and local inflammatory changes likely promoted the formation of a fistulous communication between the common bile duct and the duodenum. This was confirmed by MRCP and duodenoscopy, which showed a patent choledochoduodenal fistula with normal biliary drainage and preserved liver function.

This rare evolution has important clinical implications. While standard management would have been delayed biliary-enteric anastomosis, the spontaneous establishment of internal drainage permitted a conservative, non-operative approach. Despite the favorable short-term outcome, patients with spontaneous biliary-enteric fistulization remain at risk for long-term complications, including recurrent cholangitis, spontaneous fistula closure with secondary biliary obstruction, and late biliary stricture formation. Consequently, prolonged follow-up with clinical assessment, liver function tests, and imaging when indicated is essential. Nevertheless, similar to the few isolated cases reported in the literature [5, 14], our patient’s favorable outcome illustrates that spontaneous biliodigestive fistulization is an exceptional good outcome to a misfortunate accident, but with great vigilance to surveillance.

This case highlights several key messages. First, traumatic extrahepatic biliary injuries are rare but require a high index of suspicion, particularly in penetrating trauma and when vascular injuries are present. Second, CT imaging may fail to identify bile duct injuries, and even during emergency surgery, these lesions can be missed. Third, damage control strategies are crucial in unstable patients, with delayed repair after stabilization offering safer conditions for reconstruction. Finally, the spontaneous development of a choledochoduodenal fistula observed in this case represents an exceptional and unpredictable event, and should not be interpreted as a therapeutic alternative to standard biliary reconstruction. Current management of major bile duct injuries remains surgical, most commonly by hepaticojejunostomy in appropriate conditions.

Limitations: This report describes a single patient and therefore cannot be generalized. Although intraoperative findings were strongly suggestive of complete common bile duct transection, definitive anatomical characterization with ERCP or percutaneous transhepatic cholangiography was not pursued after MRCP demonstrated effective internal biliary drainage, given the patient’s favorable clinical course. Imaging interpretation was limited by postoperative anatomical distortion and the absence of standardized sequential cholangiography. Nevertheless, the consistent correlation between clinical evolution, biochemical normalization, and imaging findings supports the validity of the reported outcome.

Conclusion

Traumatic injuries to the extrahepatic biliary tree remain exceedingly rare and are often associated with severe concomitant hepatic and vascular damage, making their diagnosis and management particularly challenging. In unstable patients, a staged approach combining rapid hemorrhage control, bile diversion, and delayed definitive biliary reconstruction is generally recommended.

This case illustrates that, in some fortunate cases, spontaneous internal biliary drainage through a choledochoduodenal fistula may occur, allowing for a conservative, non-reconstructive strategy with favorable long-term outcomes. Careful postoperative surveillance and appropriate imaging are essential to detect such evolutions and to avoid unnecessary surgery. Ultimately, individualized management based on the patient’s physiological status, the extent of injury, and postoperative evolution remains key to achieving optimal results.

Author contributions

Dr Souhaib Atri, MD: conceptualization , data curation, project manager, reviewing original draft, Dr Mahdi Hammami, MD¹ (Corresponding author) – data curation, writing original draft, Dr Amine Sebai, MD¹ – data curation Dr Ahmed Ben Mahmoud, MD¹ – methodology, Dr Rachid Ksantini, MD¹ – supervision , validation Dr Mohamed Jouini, MD¹ –supervision , validation Dr Anis Haddad, MD¹ – resources Dr Montassar Kacem, MD¹ – supervision, validation.

Funding

There was no source of funding for this study.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethical approval

Not applicable. Our institutions require no ethical approval for case reports

Consent for publication

Written informed consent was obtained from the patients for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests

The authors declare no competing interests.