Intra Vascular Ultra Sound: One More Tool to Diagnose Aorto-duodenal Fistula

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.

Aortic Bulge: A Possible Predictive Sign of Impending Aortoenteric Fistula

Purpose

The purpose of this study is to introduce the aortic bulge sign, a finding observed retrospectively on computed tomography prior to the acute presentation of aortoenteric fistula, and to determine its interobserver reliability.

Methods

Following research ethics board approval, all cases of aortoenteric fistula at our institution occurring from 2011–2015 were identified retrospectively. All previous computed tomography images of patients who eventually developed aortoenteric fistula were reviewed by a single observer for the presence of a potentially predictive finding of fistulization, the aortic bulge sign. These previous images were then combined with age and sex matched controls into a case bank. Eight radiology residents and staff were instructed in observing the aortic bulge sign. These observers then reviewed the case bank in a blinded analysis to determine the interobserver reliability of this finding.

Results

Fourteen cases of aortoenteric were identified. The average patient age was 70.71 years with a male-to-female ratio of 11:3. Eleven patients had previous computed tomography images available for review. With blinded analysis by multiple observers, the aortic bulge sign was identified with greater than 80% agreement in six of 11 cases (66.67%). Fleiss' kappa was calculated at k = 0.60 (95% confidence interval 0.50–0.69), corresponding to moderate-to-substantial interobserver agreement.

Conclusions

The aortic bulge sign has been retrospectively identified as a promising computed tomography finding of eventual aortoenteric fistula prior to acute presentation. Further study is required to determine the diagnostic value of this sign.

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.

Editor's Choice - Management of Secondary Aorto-enteric and Other Abdominal Arterio-enteric Fistulas: A Review and Pooled Data Analysis

OBJECTIVES

To compare management strategies for secondary abdominal arterio-enteric fistulas (AEFs).

METHODS

This study is a review and pooled data analysis. Medline and Scopus databases were searched for studies published between 1999 and 2015. Particular emphasis was given to short- and long-term outcomes in relation to AEF repair type.

RESULTS

Two hundred and sixteen publications were retrieved, reporting on 823 patients. In-hospital mortality was 30.7%. Open surgery had higher in-hospital mortality (246/725, 33.9%), than endovascular methods (7/98, 7.1%, p < .001, OR 6.7, 95% CI 3-14.7, including staged endovascular to open surgery, 0/13, 0%). In-hospital mortality after graft removal/extra-anatomical bypass grafting was 31.2% (66/226), graft removal/in situ repair 34% (137/403), primary closure of the arterial defect 62.5% (10/16), and for miscellaneous open procedures 41.3% (33/80), p = .019. Among the subgroups of in situ repair, homografts were associated with a higher mortality than impregnated prosthetic grafts (p = .047). There was no difference in recurrent AEF-free rates between open and endovascular procedures. Extra-anatomical bypass/graft removal and in situ repair had a lower AEF recurrence rate than primary closure and homografts. Late sepsis occurred more often after endovascular surgery (2-year rates 42% vs. 19% for open, p = .001). The early survival benefit of endovascular surgery was blunted during follow-up, although it remained significant (p < .001). Within the in situ repair group, impregnated prosthetic grafts were associated with the worst overall and AEF related mortality free rates and vein grafts with the best. No recurrence, sepsis, or mortality was reported following staged endograft placement to open repair after a mean follow-up of 16.8 months (p = .18, p = .22, and p = .006, respectively, compared with patients in other groups).

CONCLUSIONS

Endovascular surgery, where appropriate, is associated with better early survival than open surgery for secondary AEFs. Most of this benefit is lost during long-term follow-up, implying that a staged approach with early conversion to in situ vein grafting may achieve the best results in selected patients.

Critical gastrointestinal bleed due to secondary aortoenteric fistula

Secondary aortoenteric fistula (SAEF) is a rare yet lethal cause of gastrointestinal bleeding and occurs as a complication of an abdominal aortic aneurysm repair. Clinical presentation may vary from herald bleeding to overt sepsis and requires high index of suspicion and clinical judgment to establish diagnosis. Initial diagnostic tests may include computerized tomography scan and esophagogastroduodenoscopy. Each test has variable sensitivity and specificity. Maintaining the hemodynamic status, control of bleeding, removal of the infected graft, and infection control may improve clinical outcomes. This review entails the updated literature on diagnosis and management of SAEF. A literature search was conducted for articles published in English, on PubMed and Scopus using the following search terms: secondary, aortoenteric, aorto-enteric, aortoduodenal, aorto-duodenal, aortoesophageal, and aorto-esophageal. A combination of MeSH terms and Boolean operators were used to device search strategy. In addition, a bibliography of clinically relevant articles was searched to find additional articles (Appendix A). The aim of this review is to provide a comprehensive update on the diagnosis, management, and prognosis of SAEF.

Aortic graft in hollow viscus

Secondary aortoenteric fistulas (AEFs) and aortic graft infection are relatively rare but fatal complications of aortic surgery. A 77-year-old man had a 1-week history of fever and abdominal pain with right inguinal area swelling. The patient's medical history included hypertension, aortobifemoral bypass grafting due to right iliac artery, and superficial femoral artery occlusion. Abdominopelvic computed tomography revealed the presence of an aortic graft in the hollow viscus. Although there have been several reports of secondary AEF, there have been few reports of an aortic graft in a hollow viscus. Diagnosis of AEF can be delayed in patients with atypical symptoms. Without a high index of suspicion, this condition has fatal consequences.

Intravascular ultrasound

Intravascular ultrasound (IVUS) has an interesting history that parallels that of many of the advancements that have led to the endovascular era. The use of IVUS in conjunction with standard cross-sectional imaging and three-dimensional reconstructions offers a powerful tool in both the diagnosis and treatment of complex vascular pathology. The use of IVUS has increased over the years and is currently in the process of being incorporated into several modalities that will offer more in the way of real-time information in both the aortic arena and the treatment of increasingly complex peripheral vascular disease. Currently, we use IVUS as a powerful adjunct in combination with other modalities to increase our understanding of vessel architecture and assist in the management of complex vascular pathology.

Secondary iliac-enteric fistula to the sigmoid colon complicated with entero-grafto-cutaneous fistula

We report the case of a 67-year-old man who was admitted to our department with acute rectal bleeding. The patient had had previous aortoiliac surgery with the utilization of an aortobifemoral vascular prosthesis. Diagnosis of aortoenteric fistula was made between the distal suture line of the right graft leg and the sigmoid colon. This fistula had an enterocutaneous component. After exploratory laparotomy, primary resection of the sigmoid colon, exstirpation of the enterocutaneous fistula, excision of the right graft leg and extraanatomical crossover bypass were successfully performed. This study reports a rare type of aorto/ilac-enteric fistula to the left colon complicated with an entero-grafto-cutaneous component and describes an unusual and successful surgical treatment method.