Value of Doppler sonography for predicting clinical outcome after renal artery revascularization in atherosclerotic renal artery stenosis.

OBJECTIVE

The purpose of this study was to prospectively evaluate the usefulness of Doppler sonography for predicting blood pressure and renal function improvement after percutaneous renal angioplasty in patients with unilateral atherosclerotic renal artery stenosis.

METHODS

Thirty-six patients with successfully revascularized unilateral atherosclerotic renal artery stenosis were included. Patients were evaluated by Doppler sonography before treatment, with the resistive index (RI) and acceleration being measured in both kidneys. Blood pressure, number of antihypertensive drugs, and serum creatinine concentration were assessed before treatment and thereafter during a 23 +/- 15-month (mean +/- SD) period.

RESULTS

In 20 of the 36 patients (55%), the RI was less than 0.80 before revascularization. After treatment, blood pressure improved in 17 (85%) of those 20 patients and improved in 8 (50%) of 16 patients with an RI of greater than 0.80 (P < .05). Twenty-five patients had renal insufficiency pretreatment, and 11 (44%) had a baseline RI of less than 0.80. Improvement in renal function after angioplasty was shown in 5 (45%) of these 11 patients and in 4 (28.5%) of 14 in the group with high RI (P > .05, not significant). On analysis of acceleration, blood pressure improved in 9 (69%) of 13 patients with acceleration of greater than 3 m/s(2) and in 16 (69.5%) of 23 with acceleration of less than 3 m/s(2) (P > .05). In patients with renal insufficiency, 5 (50%) of 10 cases with normal baseline acceleration and 4 (27%) of 15 with low acceleration showed improvement in renal function (P > .05).

CONCLUSIONS

An elevated RI should not exclude patients from a revascularization procedure because, although renal RI does correlate with blood pressure response to revascularization, it is not a useful parameter in predicting renal function outcome. Acceleration has no prognostic value.