Low risk of contrast nephropathy in high-risk patients undergoing spiral computed tomography angiography with the contrast medium iopromide and prophylactic oral hydratation.

BACKGROUND

Spiral computed tomography angiography (CTA) is a sensitive and specific technique for visualizing renal arteries and diagnosing renal artery stenosis (RAS). Whether spiral CTA is associated with increased risk of contrast nephropathy (CN) in patients with impaired renal function is unknown.

METHODS

We prospectively studied 50 patients with chronic renal insufficiency (serum creatinine concentration greater than 1.58 mg/dl) who underwent spiral CTA with iopromide, a nonionic, low-osmolar contrast agent. Fourteen patients had diabetes mellitus. Patients were encouraged to drink 1 l of water 12 hours before and 2 l over 24 hours after the procedure. The presence of CN was defined by an increase of 20% or more in the baseline serum creatinine level within or 72 hours after administration of the radio-contrast agent.

RESULTS

In the entire group, mean serum creatinine levels increased significantly from 2.92 +/- 1.39 to 3.06 +/- 1.55 mg/dl (p = 0.02) and mean creatinine clearance decreased from 29.8 +/- 12.9 to 28.9 +/- 12.8 ml/min (p = 0.009) 72 h after administration of the contrast medium. Two patients experienced an increase in serum creatinine level of 20%. Renal function returned to baseline within seven days in the 2 patients. Absolute changes in creatinine clearance after the administration of radiocontrast medium were similar in nondiabetic and diabetic patients and in the subgroup of patients, with a baseline serum creatinine of < 3 mg/dl and > or = 3 mg/dl.

CONCLUSIONS

In patients with chronic renal insufficiency, spiral CTA performed with iopromide, a nonionic, low-osmolar contrast medium and a prophylactic oral hydratation, is a minimally invasive technique with low risk of contrast nephropathy.