Kidney Week

Abstract: FR-PO1003

Effect of Kidney Volume on eGFR Following Living-Donor Nephrectomy

Session Information

• Transplantation: Clinical - Pretransplantation, Living Donation, and Policies
  November 07, 2025 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 2102 Transplantation: Clinical

Authors

• Del Castillo Rix, Daniel Sebastian, Jackson Memorial Hospital, Miami, Florida, United States

Daniel Sebastian Del Castillo Rix, MD

• Medina, Adriana, Florida International University, Miami, Florida, United States

Adriana Medina

• Ortigosa Serrano, Veronica A., Mount Sinai Medical Center of Florida, Miami Beach, Florida, United States

Veronica A. Ortigosa Serrano, MD

• Mattiazzi, Adela D., Miami Transplant Institute, Miami, Florida, United States

Adela D. Mattiazzi, MD, FASN

• Cabeza Rivera, Franco H., Miami Transplant Institute, Miami, Florida, United States

Franco H. Cabeza Rivera, MD

Background

Living kidney donation remains essential in addressing the organ shortage crisis. Optimizing donor selection requires an understanding of the factors influencing post-donation kidney function. While kidney volume is hypothesized to impact outcomes due to its relationship with nephron mass, its clinical relevance remains unclear. This study evaluates the effect of removed kidney volume on eGFR decline following unilateral nephrectomy in living donors.

Methods

We retrospectively analyzed 792 living donors who underwent nephrectomy between 2011 and 2021 at a single center. Data included age, sex, race, height, weight, baseline eGFR, kidney volumes (measured via CT), and nephrectomy side. Unadjusted and adjusted regression models assessed the association between removed kidney volume and immediate post-donation eGFR drop. Longitudinal eGFR trajectories were modeled using a mixed-effects regression, adjusting for relevant covariates. Significance was set at p < 0.05.

Results

The mean age of 40.7; 63% were male, 44% were Hispanic; the mean eGFR was 106.7; most nephrectomies were left-sided (91%). Mean kidney volumes: left 169.8 cm³, right 164.4 cm³. The removed kidney volume was significantly associated with initial eGFR decline, specifically a drop of 0.006 ml/min/1.73 m² per cm. Over time, longitudinal models indicated a modest compensatory increase in eGFR of 0.014 ml/min/1.73 m per cm. The mean eGFR difference between right and left nephrectomy was -2.1 ml/min/1.73 m² (95% CI: -6.7 to 2.6), not clinically significant. Age and race were also associated with eGFR decline, at 0.2 ml/min/1.73 m² per year of age and 6 ml/min/1.73 m² lower for Black versus White donors.

Conclusion

Kidney volume, age, and race were statistically associated with post-donation eGFR, but the clinical impact of kidney size and age appears minimal. These findings suggest technical considerations, such as anatomical complexity and surgical expertise, should guide nephrectomy side selection. Persistent racial disparities in outcomes—particularly affecting Black donors—warrant further investigation to ensure equitable donor evaluation and care. Future studies should focus on identifying clinically meaningful predictors of post-donation kidney function to support more personalized donor counseling and long-term follow-up strategies.

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.2025qtpy2a7w