Increased detection of early vascular abnormalities after renal biopsies by color Doppler sonography

Objective. The purpose of this study was to assess the frequency of abnormal vascular findings after renal biopsies as detected by color and pulsed Doppler sonography. Methods. With both color and pulsed Doppler sonography, we examined 77 patients who underwent a renal biopsy of a native kidney. The examination was carried out before and immediately after the biopsy. A follow-up sonographic assessment was performed 24 hours later. If abnormal vascular findings were detected, the patients were reexamined after 2 weeks or even for a longer period. Results. Tissue samples suitable for histologic diagnosis were obtained in 94% of the biopsies. In 17 of 77 patients, changes were observed in the color and pulsed Doppler examination immediately after the biopsy. A small localized flow disturbance was diagnosed in 10 kidneys, and a color tract was seen in 7. In 1 case, this tract was associated with a small localized flow disturbance. In 2 other patients, a localized flow disturbance was detected only in the examination performed 24 hours after the biopsy. Eight of the 10 flow disturbances diagnosed immediately after the biopsy and all tracts were not visible at the 24-hour follow-up examination. All these vascular findings were undetectable on sonographic examination without color and pulsed Doppler imaging. Conclusions. The results indicate that vascular lesions, detectable with color and pulsed Doppler sonography, are not rare findings early after renal biopsies. These vascular findings show a high rate of spontaneous resolution within the first 24 hours.