Michael Azzopardi1, Tom Wallace2,
Yazan S. Khaled1,3
1Leeds Institute of Medical Research, Department of
Academic Surgery, St James’s University Hospital, Leeds, United Kingdom
2Leeds Vascular Institute, Department of Vascular
Surgery, Leeds General Infirmary, Leeds, United Kingdom
3School of Medicine, University of Leeds, United
Kingdom
“Written informed consent was obtained from the patient to publish this
report in accordance with the journal’s patient consent policy”.
Corresponding author:
Mr. Yazan S. Khaled
Leeds Institute of Medical Research & School of Medicine
University of Leeds
Clinical Sciences Building
St James’s University Hospital
Leeds, LS9 7TF
United Kingdom
Phone: +44 113 2065281
Fax: +44 113 2065281
Email: Y.Khaled@leeds.ac.uk
Keywords:
Artery-enteric fistula, gastrointestinal haemorrhage, sigmoid cancer,
graft explant.
Conflict of interest: The authors declare no conflict of interest.
Abastract
This case study discusses the staged management of a 78-year old patient
presenting with life-threatening lower gastrointestinal (GI) bleeding
secondary to an aortoiliac graft-enteric fistula (GEF) into the sigmoid
colon on the background of an adenocarcinoma and diverticular disease.
The patient had an aorto bi-iliac synthetic dacron graft repair of an
abdominal aortic aneurysmal (AAA) some 20 years prior. Here, we present
a case of successful endovascular treatment of massive haemorrhage, as a
bridge to definitive second-stage dacron graft explant and autologous
vein reconstruction with a simultaneous anterior resection.
Background
Arterio-enteric fistula (ArEF) is an umbrella term that encompasses
various fistulations between the great arteries and the gastrointestinal
(GI) tract, including aortoesophageal, aortogastric, aorto-enteric
fistulas (AEF) and iliac artery-enteric fistula (IEF).
ArEF is a rare cause of potentially lethal GI bleeding and the vast
majority appear to occur in the aorta, with few examples of IEF
encountered in modern literature. These fistulas can occur via two
separate pathological mechanisms. Primary ArEF are rare, occurring as a
spontaneous communication between an artery and bowel from a combination
of direct frictional forces and inflammatory processes [1]. The most
encountered mechanism contributing to primary ArEF is aneurysmal
formation, which is theorised to develop into a fistula from the
repetitive mechanical forces exacerbated by cardiac pulsations and
peristaltic movements [2]. This gradual degradation and erosion of
the outermost layers of bowel and artery can also result spontaneously
in other pathological circumstances; including tumours, diverticular
disease, sepsis, syphilis and tuberculosis [3-6].
Secondary ArEFs are much more common given that they are an iatrogenic
complication of open or endovascular AAA repair using synthetic graft.
In this case, seeding of bacteria onto the synthetic graft is known to
exacerbate the erosive mechanisms involved in fistula formation [2].
Hallet et al . have suggested a 1.6% chance of fistula formation
after AAA graft repair [7]. The vast majority of ArEFs encountered
in literature are between the abdominal aorta and duodenum due to their
intimate anatomical association. IEFs are rarely encountered, but it
appears that the majority occur secondary to pelvic surgery, malignancy,
radiotherapy and infection [8].
In this case report we
encountered a 78-year old patient, 20 years after an elective AAA
Y-graft repair, presenting to emergency with haematochezia as a result
of a fistula between the right common iliac artery (CIA) and sigmoid
colon. The patient was known to have a sigmoid adenocarcinoma and
diverticular disease from a colonoscopy three weeks prior to his
emergency presentation. The rarity and complexity of this case
necessitated a multidisciplinary staged approach to the management, both
in the acute and elective setting, leading to a favourable outcome.