Perfusion parameters (PP) and early transplant outcome data from 332 consecutive ECD type kidneys machine preserved on the Waters RM-3 apparatus were reviewed and analyzed to examine the validity of using suboptimal PPs (renal resistance of .41-.60) as a criterion for discarding kidneys. Overall discard rate was 23.5%, with 55% of these having "poor" PP as part of reason for discard. PP analysis after 4 hours on the RM-3 is presented. This encompasses 280 kidneys with renal resistance <= .60. Sixty-six kidneys were discarded (23.5%). Of the 214 transplanted kidneys, 146 had immediate function (IF; 68%), 63 had delayed function (DGF; 29%), and 5 never functioned (PNF; 2%). Of the 30 transplanted kidneys with renal resistance .40 to .60, 16 (53%) had IF versus 58% in kidneys with renal resistance <= .40 (P =.125). Two of the five PNF kidney had renal resistance > .40. The PP-related discard rate in the renal resistance .41 to.60 kidneys was 51% versus 17% in the ;renal resistance <= .40 (P <= .01). Based on our observations kidneys with renal resistance <= .60 should not be discarded strictly based on "suboptimal perfusion parameters." This presents an opportunity for a decrease in discard rates of ECD kidneys.
