Is the graft function of living donor renal transplants associated with renal mass matching by CT angiographic volumetry?

Abstract

r=-0.407, p=0.010; Background : The renal volume of donors can be easily measured by computerized tomographic angiography with 3-dimentional reconstruction routinely. The pre-transplant functional renal volumes of living donors may influence graft outcomes. Low functional renal mass and mismatch of donor kidney-recipient body size can lead to progressive renal injury and poor graft function. Therefore, I evaluated the association between living donor renal volumes and graft function after transplantation. Material and Methods :I carried out a single center retrospective analysis of 51 consecutive living donor renal transplantations carried out between January 2005 and December 2011. I defined the transplanted renal volume as the renal volume per unit recipient body surface area (BSA, mL/m2). The patients were divided into two groups by donor-recipient BSA ratio : group I (n=31, ≤1) and group Ⅱ (n=20, >1). I then analyzed the clinical characteristics and laboratory data of donors and recipients to measure the correlation between renal volumes and graft outcomes. Results : The renal volumes of living donors were correlated with their estimated glomerular filtration ratios (eGFR) (r =0.314, p =0.025). Serum creatinine after renal transplant was correlated with transplanted renal volume at 1, 3 and 12 months (r =-0.319, p=0.048; and r =-0.472, p=0.002). Serum eGFR was also correlated with transplanted renal volume at 3 and 12 months after renal transplant (r =0.318, p=0.049 and r =0.388, p=0.015). When I compared outcomes according to donor-recipient BSA ratio group, there were no significant differences in terms of acute and chronic rejection, infection and delayed graft function. However, serum creatinine levels at 3,6 and 12 months was higner in group I (p=0.011, p=0.022, and p=0.007) and serum eGFR at 1,3,6 and 12 months after renal transplantation was significantly lower in group I (p=0.036, p=0.042, p=0.042 and p=0.049). There was no significant difference in graft survival between the two groups. Conclusion : Renal volume in living donors may reflect their renal function and have a significant impact on graft outcomes after transplantations. Hence, renal volume matching should be considered in selecting donor-recipient pairs for living donor renal transplantation.