Inferior Long-Term Graft Survival of Suboptimal Kidneys After Living Donor Kidney Transplantation.

BACKGROUND

In living donors, if both kidneys are considered to be of equal quality, the side with favorable anatomy for transplant is usually selected. A "suboptimal kidney" is a kidney that has a significant abnormality and is chosen to maintain the principle of leaving the better kidney with the donor. We hypothesized that the long-term outcome of suboptimal kidney is inferior to that of the normal kidney.

METHODS

In a retrospective analysis of 1744 living donor kidney transplantations performed between 1999 and 2015 at our institution, 172 allografts were considered as a suboptimal kidney (9.9%). Median length of follow-up after living donor kidney transplantation was 59.5 months (interquartile range 26.3-100.8). This study strictly complied with the Helsinki Congress and the Istanbul Declaration regarding donor source.

RESULTS

The reasons for suboptimal kidneys were cysts or tumors (46.5%), arterial abnormalities (22.7%), inferior size or function (19.8%), and anatomic abnormalities (11.0%). Suboptimal kidneys showed worse long-term overall graft survival regardless of the reasons (5-year: control vs suboptimal kidney; 88.9% vs 79.3%, P = .001 and 10-year: 73.6% vs 63.5%, P = .004). Suboptimal kidneys showed a 1.6-fold higher adjusted hazard ratio (aHR) of all-cause graft loss (95% confidence interval [CI]: 1.1-2.5, P = .025) and had the same impact as older donor age (≥ 54 years old, aHR: 1.6, 95% CI: 1.1-2.4, P = .008).

CONCLUSIONS

The impact of suboptimal kidney should be factored into the donor selection process.