Optimized technique in needle biopsy protocol shown to be of greater sensitivity and accuracy compared to wedge...

Kidney biopsy is an important tool in determining allograft suitability for transplantation. Most deceased-donor renal biopsies performed today in the United States are wedge biopsies (WBs), with core needle biopsies being performed only by a minority of organ procurement organizations (OPOs). The lack of a gold standard in tissue sampling and tissue evaluation has prompted our OPO to find a more sensitive biopsy method as well as a more accurate pathology evaluation protocol to reassess expanded-criteria donor kidneys.

Between the months of March 2007 and June 2008, the New York Organ Donor Network OPO imported 226 kidneys. These kidneys had been previously biopsied by the originating OPOs utilizing the WB method. All 226 kidneys were rebiopsied by our preservation team using the optimized needle biopsy technique (ONBT) and then evaluated by the pathologists of the Transplant Pathology Laboratory of the Mount Sinai Hospital.

Histologic findings from both types of biopsies were compared in the following parameters: glomerular yield, percentage of obsolete glomeruli, tubular interstitial scarring, arterial intimal fibrosis and acute tubular necrosis. Difference in glomerular yield between WB and ONBT was not statistically significant (P = .1736). ONBT detected more tubular interstitial scarring and arterial intimal fibrous narrowing than WB (P = .00). No statistical difference was found between the two biopsy methods in identifying acute tubular necrosis.

The data suggest that there were no statistical differences in sample reliability between ONBT and WB. However, ONBT was found to be significantly more sensitive in identifying allograft tubular interstitial scarring as well as intimal fibrous narrowing. Overall this study provides proof that ONBT is a more reliable and accurate method compared to WB in identifying important parameters of renal allograft.