Percutaneous renal biopsies: accuracy, safety, and indications.

Fifty-one percutaneous renal needle biopsies were performed on 46 patients. Initial biopsy was adequate for diagnosis in 89% of patients. When a second biopsy was performed, this accuracy increased to 98%. Thirty-four of 51 (67%) biopsies were for renal masses and 17 (33%) for medical indications. Computed tomographic guidance was utilized in 94% of cases. Biopsies of renal masses were performed with 18-21-gauge needles, while biopsies for medical indications were performed with an 18-gauge cutting needle or 14-gauge Trucut. A rate of serious complications of 6% was noted.