Organ shortage is an important problem in kidney transplantation. The gap between organ demand and supply is increasing gradually. Lack of deceased donors leads to use of expended criteria, cardiac death and living donors. Recently, a new organ sourcewas added to the above mentioned options. This is the use of the kidneys procured from the patients with small renal tumors. Incidental small renal tumors are detected more frequently by using imaging methods like US, CT scan, MRI. Nephron sparing partial nephrectomy is the gold standard treatment for the patients with small renal tumors (pT1a). Thermal ablation and active follow up are recommended for the patients unfit for the surgery and with comorbid disease.  The studies conducted in the United States and England revealed that total nephrectomy is the most common treatment modality in practice (92.5%-96%).[2,3] Although the nephron sparing partial nephrectomy lately began to take place of total nephrectomy for the treatment of small renal masses, it is still not common. Nowadays, the factors for universality of the total nephrectomy could be summarized as potential risks of partial nephrectomy (bleeding, urinary leak, wound infection), experience of the surgeon and the request of the patients.
There are few reports about the use of kidneys with small renal masses in kidney transplantation. Brook et al. have compared the outcomes of kidney transplantations in patients with small renal tumors (renal cell carcinoma-pT1a-grade 1-3, papillary carcinoma-grade 1-2, chromophobe carcinomagrade 2, oncocytoma), live unrelated donors and dialysis wait-listed patients. In a subsequent matched cohort analysis, kidney recipients from donors with excised renal tumors had comparable graft than the patient survival with the kidney recipients from live unrelated donors. Patient survival for excised tumor kidney recipients was better than those who did not receive a transplant.Mannami et al reported the results by the use of not only kidneys with small renal tumors (renal cell carcinoma, pT1a, grade 1-2) but also kidneys with ureteral cancer(transitional cell carcinoma, pT1a,2,3 grade 1-3), benign diseases (angiomyolipoma, recurrent urinary tract infections, hydronephrosis due to retroperitoneal fibrosis after radiotherapy), aneurism and severe nephrotic syndrome. In this study, the graft and patient survival for 5 years and 10 years were 51.8% and 42.7%, 79.3% and 63.8, respectively. In patients of the same age group on dialysis, patient survival was 72% and 52% at 5years and 10 years, respectively. Beside the graft and patient survival, the improvement of the QoL is also another prominent benefit of the kidney transplantation.
Considering the tumor recurrence, Mannami et al reported no recurrence in the small renal tumor group but showed one at 15 months in ureteral cancer group. Brook et al reported only one tumor recurrence at 9 years after the transplant of the kidney with excised renal tumor.Sener et al reported the results of 5 kidney transplantations after tumor excision with the median 15 months (1 month to 41 months) follow up and there was no recurrence or metastatic disease in the recipients and the donors.In another study it was revealed that no recurrence of tumor by the median 69 months(14 months to 200 months) follow up of 14recipients with tumor excised kidney transplant.  These successive findings support the safe use of the kidneys from the patients with small renal tumor after excision. Availability or lack of the data for long-term follow up should be kept in mind. Transplantation of these kidneys in high risk recipients (like age over 60, no living donor, comorbid disease, estimated live expectancy in 5 years lower than 50%, with history of un successful transplantation) may be helpful to eliminate the concerns about the tumor recurrence.
The use of kidneys with incidentally detected small renal tumors during organ procurement or patient examination doesn’t prohibit the transplantation. Furthermore, earlier mentioned studies showed the possibility, feasibility and safety of utilization of the restored or tumorexcised kidneys in selective cases. When comparing with the wait-listed dialysis patients, kidney transplant recipients have the advantage of better survival and QoL, as well. In the light of this, utilization of the restored or tumor excised kidneys in selective group recipients may be helpful to expand the donor pool. In countries where the organ shortage is still a big problem,most of the transplantations are performed using organs from healthy live donors. The balance between risk and benefit for both donor and recipient should take the priority. The legislations as well as clinic protocols should be based on objective criteria and should be free from bias. Long-term followup outcomes and multicenter studies will guide the future of this approach.
- Thomas AA, Campbell SC. Small renal masses: toward more rational treatment. Cleve Clin J Med. August 2011; 78(8): 539-547.
- Hollenbeck BK, Taub DA, Miller DC, Dunn RL, Wei JT. National utilization trends of partial nephrectomy for renal cell carcinoma: a case of underutilization? Urology. 2006;67:254-259.
- Nuttall M, Cathcart P, van der Meulen J, et al. A description of radical nephrectomy practice and outcomes in England: 1995-2002. BJU Int. 2005;96:58-61.
- Mannami M, Mannami R, Mitsuhata N, et al. Last resort for renal transplant recipients, ‘restored kidneys’ from living donors/patients. Am J Transplant. 2008;8(4):811-818.
- Brook NR, Gibbons N, Johnson DW, Nicol DL. Outcomes of the transplants from patients with small renal tumours live unrelated donors and dialysis wait-listed patients. Transplant Int. May 2010;23(5): 476-483.
- Sener A, Uberoi V, Bartlett ST, Kramer AC, Phelon MW. Living donor renal transplantation of grafts with incidental renal masses after exvivo partial nephrectomy. BJU Int. December 2009;104(11): 1655-1660.
- Buell JF, Hanawway MT, Munda R, et al. Donor kidneys with small renal cell cancers: can they be transplanted? Transplant Proc. 2005 ;37: 581-582.