Cholecystoduodenal Fistula Due to Gallstone Disease Masquerading as a Duodenal Ulcer Bleed: A Case Report

Introduction

A cholecystoenteric fistula (CEF) is a rare complication of gall stone disease. It was described as a late complication of cholecystitis in 1890 [1]. While a cholecystoduodenal fistula is the most commonly occurring bilioenteric fistulous communication, cholecystocolonic, cholecystogastric, and choledochoduodenal fistulas have also been described [2–4]. Depending on their clinical presentation, they can be classified into non-obstructive and obstructive types. Cholangitis, malabsorption, and weight loss are seen in the former, while the latter presents with gallstone ileus or Bouveret syndrome [5]. We describe a rare case of cholecystoduodenal fistula presenting with upper-gastrointestinal bleed, in line with the Surgical CAse REport (SCARE) Guidelines [6].

Case Report

A 73-year-old woman with a medical history of diabetes mellitus, gallstones, and pancreas divisum presented to the Emergency Department at our district general hospital in July 2024 with a 1-week history of melena. She reported having bowel movements 4 times a day for 1 week, increasing to 7 times on the day of presentation. Upon further inquiry, she disclosed a 1-year history of acid reflux and denied any previous hospitalizations for cholecystitis. She was independent in performing activities of daily living but began experiencing exertional dyspnea since the onset of this illness. Notably, she had no abdominal pain, vomiting, or use of anticoagulants. Except for mild tachycardia, her vital signs were within normal limits, and her abdominal examination was unremarkable. She had no history of prior abdominal surgeries.

Laboratory investigations revealed a hemoglobin level of 42 g/L (down from a baseline of 139 g/L in January 2023), a hematocrit of 0.14 (normal range: 0.33–0.45), a white cell count of 17.3 (normal range: 4.2–10.6), and a normal coagulation profile. Liver function test results were normal. Her Glasgow-Blatchford score was calculated to be 11. Following hemodynamic resuscitation and transfusion of blood and blood products overnight, she underwent a gastroscopy the next morning, performed by the gastroenterology team.

The gastroscopy revealed kissing D1 ulcers (Figure 1):– A 1-cm Forrest IIc ulcer was noted, and 8 ml of adrenaline 1: 10 000 was injected for hemostasis, with a good blanching effect. However, active pus excretion suggested a possible underlying abscess.– A small Forrest III ulcer was also identified.

Additionally, a large hiatus hernia and grade A esophagitis were observed.

Subsequent cross-sectional imaging was performed, and the surgical team was consulted for further management. Contrast-enhanced CT scan of the abdomen revealed features consistent with acute cholecystitis, including submucosal abscess formation, pneumobilia, and likely fistulation between the gallbladder neck and the duodenum (Figures 2–4).

After thorough discussion and obtaining informed consent, the patient underwent an open cholecystectomy with cholecystoduodenal fistula repair. Intraoperatively, dense omental adhesions encasing the gallbladder were encountered, along with intrahepatic perforation of the gallbladder and a large gallstone within its lumen with a cholecystoduodenal fistula at the anterior surface of the first part of the duodenum. A safe cholecystectomy was performed, the fistula was taken down, and the duodenum was repaired with polydioxanone suture and an omental patch. A wide-bore abdominal drain was placed adjacent to the repair site, and a Ryle’s tube was inserted for gastric decompression.

The patient had an uneventful postoperative recovery. She was started on a diet on postoperative day (POD) 5, and the drain was removed prior to discharge on POD 8. No early postoperative complications occurred, and the incision site remained healthy. She was discharged with an empirical course of H. pylori eradication therapy. Histopathological examination of the gallbladder revealed acute-on-chronic cholecystitis, with no evidence of dysplasia or malignancy.

Discussion

Cholecystoenteric fistula (CEF) can have a wide spectrum of clinical presentations. Their prevalence in patients with cholelithiasis is estimated at 3–5% [7]. The condition is predominantly seen in older women [8]. Recurrent episodes of acute cholecystitis or chronic cholecystitis can lead to adhesions between the gall bladder and adjacent viscus. Gall stone impaction then leads to pressure necrosis, causing fistulation between the gall bladder and the viscus. Most acute cases present with gall stone ileus, Bouveret syndrome, or Mirizzi syndrome, while chronic cases present with features of chronic cholecystitis like right upper-quadrant pain and biliary colic. Rarely, they present with massive upper-gastrointestinal bleeding, like our patient, due to a marginal ulcer at the site of the fistula into the duodenum or erosion of vascular structures (cystic artery).

Physical examination results are often non-specific unless the presentation is acute, as in hollow viscus obstruction or cholangitis, and was unremarkable in our patient. Lab studies may show deranged liver function test results when associated with Mirizzi syndrome or raised inflammatory markers in the setting of acute cholecystitis. Imaging with ultrasound can reliably diagnose cholelithiasis, cholecystitis, and pneumobilia. However, it is unlikely to be of benefit in the definitive diagnosis of a bilioenteric fistula, which requires cross-sectional imaging. A CT scan is diagnostic in patients presenting with hollow viscus obstruction due to a radio-opaque gall stone. However, in the absence of a radio-opaque stone, the diagnosis is commonly (20–40%) intra-operative [9,10]. Coronal sections are required to demonstrate the fistula. Additional information, including gall bladder perforation, formation of abscesses, or abdominal collections and inflammation of the surrounding structures essential to operative planning, can be derived from cross-sectional imaging. Magnetic resonance cholangiopancreaticography (MRCP) is helpful when CEF is combined with choledocholithiasis or Mirizzi syndrome.

The definitive management of a CEF involves cholecystectomy, fistula take-down, enterolithotomy (in cases of gall stone ileus and Bouveret syndrome)/bile duct exploration, removal of the culprit stone, and repair of the penetrated organ. A 1-stage procedure in the emergency setting should be selected prudently due to the high incidence of postoperative complications and morbidity in high-risk patients, especially if the surgeon lacks expertise [11,12]. It is nevertheless the preferred procedure in low-risk patients and with an experienced surgeon. A 1-stage upfront open approach to surgery in our patient was preferred in view of anticipated extensive inflammation due to gall bladder perforation and cholecystoduodenal fistula causing recent upper-GI bleeding. While minimally invasive approaches may be appropriate in planned procedures, there is a high likelihood of conversion to open surgery in the emergency setting due to dense adhesions and an obscured Calot’s triangle [13]. A thorough review of imaging and preoperative planning help achieve favorable outcomes.

Conclusions

Cholecystoenteric fistula (CEF) is an uncommon complication of gallstone disease and can be diagnosed intraoperatively. Massive upper-gastrointestinal bleeding is a rare mode of presentation. Hemodynamic resuscitation and management of upper-GI bleed takes precedence, followed by definitive management of the CEF after establishment of the diagnosis.