MEDtube Science 2014 - The impact of kidney weight to recipient weight ratio (Kw/Rw) on kidney graft function after transplantation

Background: Kidney transplantation is the best method of renal replacement therapy. Recent studies assess the suitability of kidney selection for a recipient based on kidney weight to the recipient weight ratio (Kw/Rw). Low ratio can indicate insufficient nephron mass for the recipient. The aim of this study was to calculate Kw/Rw ratio useful to evaluate kidney function until one year post surgery. Materials and Methods: In the years 2010 – 2011 at the Department of General and Transplantation Surgery in Warsaw 262 kidney transplantations were performed. We retrospectively analyzed a group of 103 patients who underwent the transplant procedure from a deceased donor. Collected data considered delayed graft function, acute rejection episodes, creatinine, recipient survival and one year graft survival. Kw/Rw ratio was calculated for all of them. Recipients were divided into two groups: group low-ratio (n=36; Kw/Rw ratio4,29 g/kg). Short-term and one-year outcomes of transplantation were compared. Results: Creatinine was significantly better in the group of patients who received larger kidneys (ratio>4,29 g/kg). Delayed graft function (DGF) in the group with low-ratio occurred in 56% patients vs 32% in the high-ratio group (p=0,029). The group with higher Kw/Rw ratio underwent less AR episodes, but this was not statistically significant. There were no differences between graft and one-year patients’ survival between the groups. Conclusion: Kw/Rw ratio could be an additional, differentiating factor in the donor-recipient matching.