Modification of a disposable needle for renal biopsy in children and transplant recipients.

While use of a disposable biopsy needle (Tru-Cut) has been shown to result in less distortion of glomerular architecture than the reusable Franklin-Vim-Silverman needle, the long specimen notch (20 mm) makes it less desirable for use in small children or renal allograft biopsy. A simple modification of the cannula handle permits selection of any desired specimen length. Four percutaneous renal biopsies of nephrotics under 4 years of age and an additional four renal allograft biopsies were performed using this technique, resulting in adequate specimens and no complications. It is concluded that the described modification of the Tru-Cut needle may increase the safety of renal biopsy in patients at higher risk for hemorrhagic complications.