International Urology and Nephrology 27 (4), pp. 3S7-363 (199S) Core Needle Biopsy in Renal Transplantation I. E. GEt~IM,* P. ROWLANDS,** I. McDICKEN,*** A. BAKRAN,* IL A. SELLS,* M. GLADMAN,*** J. GILLIES*** Departments of*Transplantation, **Radiology and ***Pathology, Royal Liverpool UniversityHospital, Liverpool, UK (Accepted January 3, 1995) Core biopsies have been done by ultrasound assisted 18-G disposable needles with a spring loaded gun (Biopty) system in 140 renal transplant cases either for in- vestigation of an early non-functioning graft or evaluation of deteriorating graft functions. The biopsy procedure was successfullycompleted in 99.5% and sufficient amount of renal tissue was obtained in 88% of cases. The pathological diagnoses were cunfmned 100% by the other clinical parametersof cases with acute cellular re- jection, pyelonephritis, acute tubular necrosis and there was disease recurrence. In another 8 patients (6%) where the pathologicalpicture was showing either no or non- specific changes there was no major change in clinical outcome. In addition, clinical diagnoses of chronic vascular rejection and Cyclosporin A toxicity were confirmed in 93.7% and 91.7%, respectively, in biopsies of these cases. Complications were seen in 3 patientsas a bowel perforation,intra-abdominalbleeding and formation of an intrarenalarterio-venous fistula. In former two complicated cases there was no need for any extra treatment but the artcrio-venousfistulawas successfullyembo- lized through an angiography catheter without losing the graft. We conclude that the Biopty system is more efficient than the free needle aspiration biopsy especially when the pathological diagnosis can be made upon tissue components rather than cellsalone. Introduction The prognosis of kidney transplantation has significantly improved in the last few years. With regard to this improvement advances in organ storage, surgical technology and immunosuppression were the main contributors. An- other incontrovertible factor in such improvement was the instigation ofpercu- taneous needle biopsy techniques in follow-up of transplanted organs [1, 2]. In this study, our experience with a core needle biopsy technique (Biopty) in kidney transplantation is reported. Materials and methods Between October 1990 and December 1991 one hundred and forty needle core biopsies wore carried out at the Royal Liverpool University Hospital. The biopsy system (C. R. Bard, Inc., Covington GA, USA) contains an 18-G biopsy VSP, Utrecht Akad~miai Kiadt, Budapast