CT-guided renal biopsy using a coaxial technique and an automated biopsy gun.

In this series, 35 patients with medical renal disease had renal biopsy guided by computed tomography (CT). Biopsies were done by a coaxial technique in which a thin-walled 16 guage guide needle is placed adjacent to the renal capsule of the lower pole. An 18 gauge cutting needle is then placed through the guide needle, and multiple samples (2 to 4) are obtained with an automated biopsy gun. Adequacy of specimens is immediately checked in the CT suite using low-power microscopy. Specimens are submitted for light, electron, and immunofluorescence microscopy. Adequate tissue for definite diagnosis was obtained in 33 of the 35 patients (94%). One patient had moderate postbiopsy bleeding and was hospitalized. There were no major complications. CT-guided renal biopsy using a coaxial technique and automated biopsy gun is an effective means of obtaining tissue for the evaluation of medical renal disease.