Mark Goldstein MBChB, Presenter: Nothing to Disclose

Sangeet Ghai MD, Abstract Co-Author: Nothing to Disclose

Mostafa Atri MD, Abstract Co-Author: Support, Lantheus Medical Imaging, Inc

Lindsay Jacks, Abstract Co-Author: Nothing to Disclose

Martin E. O'Malley MD, Abstract Co-Author: Nothing to Disclose

1) To retrospectively assess factors affecting the success of ultrasound guided core biopsy of native and transplant kidneys. 2) To attempt to determine if an algorithm for predetermined number of passes can be obtained.

This was an ethics board approved retrospective study. 500 consecutive non-focal renal biopsies were identified between June 2005 and December 2007 with a documented no. of biopsy passes. All biopsies were targeted to yield maximal renal cortex and performed with 18-gauge automatic biopsy needles by abdominal radiologists or trainees under sonographic guidance. No. of biopsy passes and specimen adequacy was determined by an on-site cyto-technologist using light microscopy with the aim to achieve ≥15 glomeruli as per our institutions criteria. Serum creatinine, body mass index (BMI), needle type (Bard/ Temno), transplant age, kidney size, diabetic status, and operator were recorded. Univariate analysis was performed to determine the variables predicting no. of biopsy passes. Multivariate logistic regression was used to determine predictors of >3 biopsy passes.

474 biopsies (338 transplant, 136 native) were included for statistical analysis. 95% of biopsies were adequate for histological diagnosis with 56% achieving ≥15 glomeruli. Mean no. of passes for all kidneys was 2.87, and was significantly more for native kidney (3.1 v 2.78, p=0.002). Mean no. of glomeruli yielded per pass was significantly greater from transplant kidneys (7.2 v 6.1, p=0.0002). Native kidney, increasing creatinine level, trainee biopsy operator, and use of a Temno needle were found to be independent predictors of having >3 biopsy passes on multivariate analysis. Native kidneys were 2 times as likely to have >3 biopsy passes (OR=2.0, p=0.02). Age at biopsy, gender, BMI, and diabetic status were not found to be associated with the no. of biopsy passes.

In the absence of an on-site cyto-technologist 3 passes would on average be adequate to make a histological diagnosis. A single pass would on average yield the minimum no. of glomeruli (7) from transplant kidneys as per the Banff 97 criteria, with 2 passes required to yield an adequate sample of ≥10 glomeruli.

3 biopsy passes would on average be adequate for random biopsies to make a histological diagnosis in the absence of an on-site cyto-technologist potentially reducing time and cost.

Goldstein, M, Ghai, S, Atri, M, Jacks, L, O'Malley, M, Non-focal Renal Biopsies: Adequacy and Factors Affecting a Successful Outcome.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9003430.html