Renal artery stenosis: detection and quantification with spiral CT angiography versus optimized digital subtraction angiography.

PURPOSE: To compare spiral computed tomographic (CT) angiography with optimized digital subtraction angiography (DSA) for accurate detection and quantification of renal artery stenosis. MATERIALS AND METHODS: In 71 consecutive patients with possible renovascular hypertension, spiral CT angiography was performed of the renal arteries before DSA. Optimized DSA (performed with projection angles calculated from axial spiral CT source images) was used as the standard. Two independent observers evaluated spinal CT angiograms for the presence and grade of renal artery stenosis. Sensitivity, specificity, and interobserver variability were calculated. RESULTS: With spiral CT angiography, all 166 renal arteries and accessory arteries were identified correctly by both reviewers. Overall sensitivity and specificity for assessment of stenoses of grade 0 (none), grade 1 (1%-49%), grade 2 (51%-99%), and grade 3 (occlusion) were 97% and 100%, 92% and 98%, 96% and 96%, and 100% and 100%, respectively. Agreement was strong between spiral CT angiographic and DSA findings in assessment of all grades of stenosis (kappa coefficient, 0.9 and 0.9, respectively) for the two observers. CONCLUSION: Spiral CT angiography enabled accurate assessment of renal artery stenosis in patients with possible renovascular hypertension and may assist in selecting patients for interventional treatment.

Complications during renal artery stent placement for atherosclerotic ostial stenosis.

PURPOSE: To describe short-term complications during stent placement for atherosclerotic renal artery ostial stenosis. METHODS: Sixty-one arteries in 50 patients were treated with Palmaz stents. Nineteen patients had a single functioning kidney, 23 had a bilateral stenosis, which was stented bilaterally in 11, and 8 had a unilateral stenosis. The complications were grouped as those related to the catheterization procedure, those related to stent placement, and those possibly related to either category. The complications were divided into those with severe clinical significance (SCS), those with minor clinical significance (MCS), and radiological-technical complications (RTC). The stent placement procedures were ordered chronologically according to examination date and the complications were tabulated per group of 10 patients. RESULTS: Five (10%) SCS, 5 (10%) MCS, and 8 (16%) RTC occurred in 50 patients. The catheterization procedure led to 2 SCS, 3 MCS, and 1 RTC. Stent placement gave rise to 7 RTC. Three SCS and 2 MCS could have been related to either catheterization or stent placement. More SCS occurred in the first group of 10 patients than in the following groups. CONCLUSION: Renal artery stent placement for atherosclerotic ostial stenosis has a considerable complication rate and a learning curve is present. The complications related to the actual stent placement were without clinical consequences.

Renal artery origins: location and distribution in the transverse plane at CT.

PURPOSE: To determine the in situ location and distribution of the renal artery origins in the transverse plane with computed tomography (CT). MATERIALS AND METHODS: CT scans of the paired main renal arteries in 200 patients (89 men, 111 women) were retrospectively reviewed. The locations of the renal artery origins, defined on the basis of their optimal profile angles, and the angle between them were measured. The degree of aortic atherosclerosis was graded in 119 of the 200 patients. RESULTS: The origins of 400 paired main renal arteries were identified. A statistically significant difference was found between the average best profile angle on the right (24 degrees [range, 26 degrees-70 degrees]) and that on the left (5 degrees [range, -75 degrees to 38 degrees]) (P < .001). Truly laterally located renal arteries were seen on the right in 11 (5%) of 200 right renal arteries and on the left in 56 (28%) of 200 left renal arteries. One hundred eighty-six (93%) of 200 right ostia and only 40 (20%) of 200 left ostia were in an anterolateral location. One hundred four (52%) of 200 left ostia and three (2%) of 200 right ostia were in a posterolateral location. The prevalence of truly opposite renal arteries was 17%. The average profile angle between the renal artery origins was 161 degrees (range, 72 degrees-225 degrees) and was significantly larger in women (P = .001). No relationship was found between ostial location and patient age or atherosclerotic grade. CONCLUSION: In the transverse plane, the location of the origin of the right renal artery tended to be anterolateral and of the left renal artery tended to be posterolateral or lateral. The variation in location and distribution width was great.