Structural and Functional Adaptation of the Remnant Kidney After Living Kidney Donation: Long-Term Follow-up

Objective Several adjustments occur after nephrectomy (NT) in the donor's remnant kidney. We investigated kidney donors 10 years after NT and compared several parameters before and after transplantation. Methods A total of 42 kidney donors of the University of Luebeck's Transplant Center were scheduled for a 10-year follow-up and were offered several investigations: laboratory tests, urinalysis and kidney ultrasound examination including determination of kidney volume (KV), resistive index (RI) and pulsatility index (PI). Moreover, a 24-hour ambulatory blood pressure monitoring (ABPM) was performed. A review of the medical records allowed comparison of the investigated parameters before (t₀), 1 month after (t_0.1), and 10 (t₁₀) years after NT. Results Creatinine clearance decreased from 94.3 ± 23 (t₀) to 52.4 ± 22 mL/min/1.73 m² (t_0.1) and increased to 78.2 ± 19 mL/min/1.73 m² after 10 years (t₁₀). Tubular proteinuria (α₁-microglobuline) increased from 6.1 ± 1.5 (t₀) to 63 ± 4.8 (t_0.1) (P <.05) and decreased to 36 ± 2.4 mg/g creatinine at t₁₀ (P <.05). Ultrasound examinations revealed a growth of the KV from 159.8 ± 23.1 (t₀) to 175.5 ± 22.1 mL (t₁₀) (P <.05) and an increase of RI and PI from t₀ of 0.63 ± 0.01 and 1.03 ± 0.03 to t₁₀ of 0.72 ± 0.04 (P <.05) and 1.24 ± 0.11 (P <.05), respectively. Post-NT ABPM values were not significantly different from pre-NT values. Conclusions NT leads to hypertrophy of the remnant kidney associated with an increase of organ volume and creatinine clearance after 10 years of follow-up. Our results indicate an excellent prognosis for the kidney donors without any signs of renal damage.