Aorto-enteric fistula: unusual CT appearance

Digestive hemorrhage and fever as a result of a double secondary aortoenteric fistula following the repair of a juxtarenal abdominal aortic aneurysm and an infection of the aortobifemoral bypass graft: a case report

A double secondary aortoenteric fistula (AEF) occurs in a patient who has had significant aortic surgery and is characterized by a direct connection between the gastrointestinal (GI) tract and the aorta at two separate sites.

IMPORTANCE

During aortoc reconstructive surgery, the patient may present with a variety of unusual complaints, including fever and GI bleeding. These symptoms are indicative of problems, including the development of an aortoentric fistula, particularly when there is a double secondary fistula.

CASE PRESENTATION

The patient was admitted to the hospital due to hematemesis, melena, and high-grade fever after undergoing synthetic grafting aortobifemoral bypass (anatomical reconstruction) and partial resection of the juxtarenal abdominal aortic aneurysm. Pus discharge and a double aortoenteric fistula in unusual sites such as the second-third portion of the duodenum and caecum are visible in upper GI endoscopy and computed tomography angiography. The patient underwent a two-stage open surgery, the first stage involving aortic limb graft exclusion and extra anatomical reconstruction, and the second stage involving graft removal, fistula management, and bowel repair. Then the patient spent a few days in the surgical intensive care unit before being discharged.

CLINICAL DISCUSSION

Primary and secondary AEF are the two categories of AEF. In patients who underwent aortic reconstruction surgery, the frequency of secondary AEF ranges from 0.36 to 1.6%. Due to the 8:1 injury ratio in the secondery AEF, men suffer more injuries than women.There are two types of fistula depending on whether or not the suture line is involved. The first form is graft enteric erosion, which excludes the suture line, while the second type is entric graft fistula, where the suture line is included. Most common site fistula is third and fourth part of duodenum and least common site is fistula formation in large bowel.

CONCLUSIONS

An uncommon complication is double secondary AEF following aortic reconstruction surgery. Since one of the most significant presentations an AEF patient can present with is major GI bleeding and sepsis, A delay in seeking immediate medical treatment could result in the patient's death. It should be emphasized that one of the mechanisms for AEF formation and a frequent cause of sepsis in patients is recurrent aortic graft infection following aortic reconstruction surgery.

Secondary aortoenteric fistula possibly associated with continuous physical stimulation: a case report and review of the literature

BACKGROUND

Secondary aortoenteric fistula is a rare but fatal complication after reconstructive surgery for an aortic aneurysm characterized by abdominal pain, fever, hematochezia, and hematemesis, and the mortality rate is high. It has been suggested that it arises due to either continuous physical stimulation or prosthesis infection during primary surgery. We describe an aortoenteric fistula following reconstructive surgery for an abdominal aortic aneurysm together with postmortem pathological findings.

CASE PRESENTATION

A 59-year-old Japanese man who had undergone reconstructive surgery for an abdominal aortic aneurysm 20 months earlier presented with the chief complaint of hematochezia and malaise. Esophagogastroduodenoscopy and total colonoscopy revealed only colon diverticula with no bleeding. Contrast-enhanced computed tomography revealed gas within the aneurysm sac and adhesion between the replaced aortic graft and intestinal tract, suggesting a graft infection. After 18 days of antibiotic treatment, he suddenly went into a state of shock, with massive fresh bloody stool and hematemesis, followed by cardiac arrest. An autopsy revealed communication between the artery and the ileum through an ulcerative fistula at the suture line between the left aortic graft branch and the left common iliac artery. Pathological analysis revealed tight adherence between the arterial and intestinal walls, but no marked sign of infection around the fistula, suggesting that the fistula had arisen due to physical stimuli.

CONCLUSIONS

Pathological analysis suggested that the present secondary aortoenteric fistula arose due to physical stimuli. This reaffirms the importance of keeping reconstructed aortas isolated from the intestine after abdominal aortic aneurysm surgery.