Contrast media nephropathy: intravenous CT angiography versus intraarterial digital subtraction angiography in renal artery stenosis: a prospective randomized trial.

BACKGROUND: Spiral computed tomographic angiography (CTA) is a noninvasive method to diagnose renal artery stenosis (RAS). In digital subtraction angiography (DSA), contrast media (CM) is injected directly into the renal artery; in CTA, a greater amount of CM is injected intravenously, potentially leading to an increased incidence of CM nephropathy. METHODS: We investigated 80 patients with suspected RAS randomized to either CTA or DSA prospectively. The following parameters were determined: serum creatinine level and single-shot inulin clearance for evaluation of renal function and urine alpha1-microglobulin and beta-N-acetyl-glucoseaminidase (beta-NAG) as markers for tubular toxicity. Data from 16 patients undergoing angioplasty in the same session were excluded. RESULTS: In the CTA and DSA groups, 163 +/- 13 and 104 +/- 56 mL of CM (mean +/- SD; P < 0.0001) were administered, respectively. Mean serum creatinine levels increased from 1.78 +/- 1.61 to 1.92 +/-1.73 mg/dL (157 +/- 142 to 170 +/- 153 micromol/L; P = 0.00001) in the CTA group and from 1.52 +/- 1.23 to 1.60 +/- 1.28 mg/dL (134 +/- 109 to 141 +/- 113 micromol/L; P = 0.01) in the DSA group. Mean inulin clearance decreased from 63 +/- 28 to 58 +/- 23 mL/min (P = 0.01) and 65 +/- 26 to 62 +/- 26 mL/min (P < 0.01), median beta-NAG levels increased from 4.6 to 6.0 U/g creatinine (P = not significant) and 2.5 to 8.0 U/g creatinine (P < 0.001), and median alpha1-microglobulin levels increased from 13 to 17 microg/g creatinine (P < 0.025) and 11 to 21 microg/g creatinine (P = not significant) in the CTA and DSA groups, respectively. CM nephropathy occurred in 3 of 33 patients in the CTA group and 2 of 31 patients in the DSA group. The increase in creatinine level was reversible in all patients within 7 days. CONCLUSION: On this study, CTA performed for the detection of RAS is not associated with an increased risk for CM nephropathy compared with intraarterial DSA despite a greater dose of CM.

Angiography for renal artery stenosis: no additional impairment of renal function by angioplasty.

The aim of this study was to compare renal function between patients with renal angiography and patients with renal angiography and angioplasty (AP) for renal artery stenosis (RAS). Forty-seven patients with suspected RAS were prospectively investigated by digital subtraction angiography (DSA) using non-ionic low osmolar contrast media (CM). In 22 patients RAS was detected and in 16 cases an angioplasty was performed in the same session. The following parameters were determined 1 day prior to and after the DSA, respectively: serum creatinine (S-Crea, micromol/l) and single-shot inulin clearance (In-Cl, ml/min) for the evaluation of renal function; and urine alpha 1-microglobuline (AMG, microg/g Crea) and beta-N-acetyl-glucoseaminidase (beta-NAG, U/g Crea) as markers of tubular toxicity. Serum creatinine was measured additionally 2 days after CM had been injected. In both groups with and without AP 174+/-65 and 104+/-56 ml of CM ( p<0.0005) were used, respectively. There were no differences with regard to renal function or risk factors for CM nephrotoxicity between both groups. In the group with AP S-Crea and In-Cl (each: mean+/-SD) did not change significantly (before DSA: 171+/-158 and 61+/-24, after DSA: 189+/-177 and 61+/-25, respectively), beta-NAG (median) rose from 4 to 14 ( p<0.05) and AMG from 8 to 55 (n.s., because of high SD). In the group without AP S-Crea increased from 134+/-109 to 141+/-113 ( p<0.01), In-Cl dropped from 65+/-26 to 62+/-26 ( p<0,01), beta NAG (median) rose from 4 to 8 ( p=0.01), and AMG from 7 to 10 (n.s.). A rise in baseline S-Crea by more than 25% or 44 micromol/l occurred in 4 and 2 patients in the group with and without AP, respectively. Creatinine increase was reversible in all cases within 7 days. In this study using sensitive methods to detect changes of renal function and tubular toxicity no additional renal function impairment in DSA with angioplasty for RAS compared with DSA alone could be demonstrated. Our data suggest that AP performed for RAS has a beneficial effect on renal function.