Isolated iliac aneurysms.

Isolated iliac aneurysms are relatively infrequent, often difficult to detect and therefore rarely considered in the differential diagnosis. Because of their close anatomical relationship to the ureters, bladder, colon, pelvic veins, femoral and sciatic nerve roots one is often misled. The consequences can be grave; chronic ureteric obstruction for instance can cause damage to one or both kidneys. With the growing frequency of tube grafting for aortic aneurysms it becomes increasingly important to consider the prevalence and incidence of isolated iliac aneurysms. The aim of this study is to report the incidence, clinical course and outcome of these lesions. In a consecutive series of 678 aorto-iliac aneurysms in the years 1972-1988 there were 53 isolated iliac aneurysms (7%) ranging in size from 3.5-14 cm whereas the reported incidence in the literature lies between 1-2%; the prevalence in consecutive autopsy series is even less than 1%. CT scanning proved to be the gold standard for the evaluation of pelvic aneurysmal disease whilst angiograms were of little help. A palpable mass was present in nine cases; GI-tract signs in 12 (five patients being operated on for suspicion of appendicitis or sigmoiditis), the genito-urinary tract was involved in eight cases, sciatic or femoral root nerve compression occurred in seven, recurrent pulmonary embolism in two, lower extremity ischaemia in seven and a-v fistula in one. The male:female ratio was 51:2 and that of ruptured to non-ruptured aneurysms 15:38. The site of isolated iliac aneurysms was the common and/or the internal iliac artery uni- or bilaterally. The external iliac artery was never involved.(ABSTRACT TRUNCATED AT 250 WORDS)