The isolated internal iliac artery aneurysm--a review.

BACKGROUND: The isolated internal iliac artery aneurysm (IIIAA) is rare but rupture has a high mortality rate. This paper reviews the available literature regarding the epidemiology, aetiology, natural history, diagnosis and management with a focus on aneurysms of atherosclerotic origin.
METHODS: A literature search was performed using internet databases PubMed, Medline and Medscape followed by manual cross referencing of relevant articles. Data were retrieved from the papers, tabulated and analysed to form a review of atherosclerotic IIIAA.
RESULTS: Three hundred and seventy-two papers were found relating to internal iliac artery aneurysms in general and 82 were directly relevant to this paper, reporting 94 cases of atherosclerotic IIIAA. For atherosclerotic aneurysms, the median (range) age was 71.9 (47-89) years and 95% were male. The natural history is unclear but is probably one of increasing size, with corresponding increased risk of rupture. Presentation was with rupture in 40%, leading to rapid death if untreated. The death rate in the group as a whole was 31%. The median (range) size of aneurysms at diagnosis was 7.7 (2-13) cm and death was significantly associated with rupture (Spearman correlation coefficient r=0.327, p=0.007). Symptoms included abdominal pain (31.7%), urological symptoms (28.3%), neurological symptoms (18.3%), groin pain (11.7%), hip or buttock pain (8.3%) and gastrointestinal symptoms (8.3%). Diagnosis may also be coincidental as a result of investigation for other conditions. Of particular use in diagnosis and assessment are ultrasound, computerised tomography and magnetic resonance angiography. Surgical treatment is difficult but can be achieved by ligation, excision or endoanneurysmorrhaphy. More recently, radiological treatments include coil embolisation and endoluminal stenting (often in combination) with the established advantages of endovascular repair have yielded promising short term results, although long term follow-up is required to assess complications and the durability of the devices.
CONCLUSIONS: Atherosclerotic IIIAA is a rare condition and if undiagnosed is often fatal. Early diagnosis and treatment may reduce morbidity and mortality particularly with the advent of endovascular techniques.