Renal failure from obstructive uropathy secondary to aortic aneurysm

The impact of computed tomography in the diagnosis and postoperative follow-up of ureteric obstruction in aorto-iliac aneurysmal disease

Between 1979, the advent of computed tomography in our institution, and 1987 we have treated 520 aorto iliac aneurysms surgically, almost 2/3 on an elective basis, the others (183 = 35.2%) being ruptured. Among non-ruptured aneurysms 220 were symptomatic and 19 of 20 cases with ureteric entrapment occurred in these patients corresponding to 8.6% of this subgroup and verified at surgery. In all of these cases the association between ureteric obstruction and the underlying aneurysmal disease was clearly documented by computed tomography. In 8 patients ureteric entrapment was caused by an inflammatory aneurysm, in 12 cases by an arteriosclerotic aneurysm which in one case was a largely expanded internal iliac aneurysm left behind during previous surgery for a ruptured aorta aneurysm. Postoperative follow-up studies of the 8 patients with an inflammatory aneurysm revealed a time-dependent regression heading towards complete disappearance of perivascular fibrosis. Because of potential difficulties associated with the surgical treatment of inflammatory aneurysms it is important to identify perivascular fibrosis and its extent and localization pre-operatively, which can only be achieved by a CT scan. Simultaneously, CT offers information concerning the presence and degree of pyelectasis and calyceal dilatation, identifies the localisation of ureteric entrapment, defines the extent of aneurysmal disease of the iliac arteries, is best-suited for postoperative follow-up in all of the cases and has the most to offer if contrast medium investigations are contra-indicated in the presence of renal insufficiency. Probably the main reason, if not the only one for preoperative angiography, is to demonstrate associated anomalies of the visceral arteries the state of which however, can be just as well assessed by duplex sonography. Thus, computed tomography is the single most important diagnostic tool in the assessment of aorto-iliac aneurysmal disease especially when associated with ureteric entrapment.