Follow-up rates of living kidney donor in Japan: A single center study

Follow-up After Donor Nephrectomy in Living Kidney Donors: How to Manage Living Kidney Donors Postoperatively

BACKGROUND/AIM

This study investigated the follow-up rate of living kidney donors and explored the factors related to continuous follow-up and remnant renal function, enabling the optimal management of living kidney donors.

PATIENTS AND METHODS

We retrospectively evaluated 180 living kidney donors who underwent donor nephrectomies at our institute. Clinical information was obtained from medical charts, and remnant renal function was defined as the estimated glomerular filtration rate 12 months after donor nephrectomy.

RESULTS

Overall, 6/180 donors (3.3%) were lost to follow-up within a year, and the follow-up rate gradually declined yearly. Independent risk factors for loss to follow-up included a follow-up period <60 months and graft survival of the recipient (p=0.002 and p=0.043, respectively). Recipient survival was correlated with loss to follow-up; however, this was not significant (p=0.051). Regarding remnant renal function, age ≥60 years, preoperative estimated glomerular filtration rate <74 ml/min/1.73 m2, and a Δsingle-kidney estimated glomerular filtration rate <9.3 ml/min/1.73m2 were independent risk factors for poorly preserved remnant renal function (p=0.036, p<0.0001, and p<0.0001, respectively). Using propensity score matching to adjust for preoperative factors, a Δsingle-kidney estimated glomerular filtration rate <9.3 ml/min/1.73 m2 was the only significant postoperative factor for poorly preserved remnant renal function (p=0.023).

CONCLUSION

An increased 5-year follow-up rate could lead to an increase in long-term follow-up, and recipient prognosis may be correlated with the living kidney donor follow-up status. Furthermore, Δsingle-kidney estimated glomerular filtration rate was identified as a factor for establishing the optimal precision follow-up management of living kidney donors.

Longitudinal mortality risks and kidney functional outcomes in Japanese living kidney donors

OBJECTIVES

Previous studies suggested that living kidney donors do not have a higher risk of death or kidney failure than the general population. However, living kidney donor risk is controversial. Furthermore, only a few studies have evaluated long-term kidney function after kidney donation.

METHODS

This study evaluated Japanese kidney donor' long-term outcomes, including mortality and kidney function. From 1965 to 2015, 230 donors (76 males, 154 females, and a median age of 54) were enrolled in this study. The median observation period was 11.0 (range, 0.3-41.0) years.

RESULTS

In total, 215 donors were still alive, and 15 had died. Causes of death included malignancies, cardiovascular disease, pneumonia, suicide, gastrointestinal bleeding, and kidney failure. Actual donor survival rates at 10, 20, and 30 years were 95.3%, 90.7%, and 80.9%, respectively. These values were comparable to age- and gender-matched expected survival. Long-term kidney function after donation was evaluated in 211 donors with serum creatinine data. Two donors developed kidney failure 24 and 26 years post-donation, respectively. The percentage of donors whose estimated glomerular filtration rate (eGFR) remained ≥45 mL/min/1.73 m2 at 10, 20, and 30 years after donation were 84.2%, 73.0%, and 63.9%, respectively. Survival rates of donors with eGFR <45 mL/min/1.73 m2 were comparable to those in persons with eGFR >45 mL/min/1.73 m2.

CONCLUSION

Our findings revealed that kidney donors did not have a higher long-term risk of death than the general population. Although some donors showed decreased kidney function after donation, kidney function did not impact their survival.

Impact of Preoperative Abdominal Visceral Adipose Tissue Area and Nutritional Status on Renal Function After Donor Nephrectomy in Japanese Living Donors for Renal Transplantation

BACKGROUND Living kidney donors face the risk of renal dysfunction, resulting in end-stage renal disease, cardiovascular disease, or cerebrovascular disease, after donor nephrectomy. Reducing this risk is important to increasing survival of living donors. In this study, we investigated the effect of preoperative distribution of abdominal adipose tissue and nutritional status on postoperative renal function in living donors. MATERIAL AND METHODS Seventy-five living donors were enrolled in this retrospective study. Preoperative unenhanced computed tomography images were used to measure abdominal adipose tissue parameters. Prognostic nutritional index (PNI) was used to assess preoperative nutritional status. Donors were divided into 2 groups according to abdominal visceral adipose tissue (VAT) area at the level of the fourth and fifth lumbar vertebrae (<80 or ≥80 cm²). Postoperative renal function was compared in the 2 groups, and prognostic factors for development of chronic kidney disease (CKD) G3b were identified using multivariate analysis. RESULTS Donors with a VAT area ≥80 significantly more often had hypertension preoperatively. Although there was no significant difference in preoperative estimated glomerular filtration rate (eGFR) between the 2 groups, postoperative renal function was significantly decreased in donors with a VAT area ≥80 compared to those with a VAT area <80. In multivariate analysis, VAT area ≥80 and PNI <54 were independent factors predicting the development of CKD G3b after 12 months. CONCLUSIONS Our findings suggest that preoperative VAT and PNI affect postoperative renal function. Further research is required to establish appropriate exercise protocols and nutritional interventions during follow-up to improve outcomes in living donors.