Predonation Body Surface Area: Normalized CT Renal Volume as a Predictor of Early Remnant Kidney Dysfunction in Living Kidney Donors

Background: Ensuring donor safety in living donor kidney transplantation (LDKT) requires reliable prediction of remnant renal function. CT volumetry provides an anatomical surrogate for nephron mass, but its predictive accuracy for post-donation dysfunction remains under-explored. Methods: This prospective study enrolled 115 voluntary kidney donors at a tertiary care centre in India. Preoperative CT renal angiography was performed to assess cortical and total renal volumes, which were normalized to body surface area (BSA). Renal function was evaluated using 24-hour urine creatinine clearance and urinary albumin-to-creatinine ratio (UACR), pre-donation and at 6 months post-nephrectomy. Remnant kidney dysfunction was defined as creatinine clearance <60 mL/min and/or UACR ≥30 mg/g. Results: At 6-month follow-up, 21.7% of donors developed microalbuminuria, while none progressed to moderate or severe renal dysfunction. A significant correlation was observed between lower pre-donation whole kidney volume-to-BSA ratio and the development of renal dysfunction (p < 0.05). CT volumetry outperformed demographic predictors (age, gender, BMI) in identifying at-risk donors. ROC curve analysis demonstrated good diagnostic performance of volume parameters for predicting post-donation renal impairment. Conclusion: Pre-donation BSA-corrected renal volume measured via CT volumetry is a strong, non-invasive predictor of early remnant kidney dysfunction in LDKT donors. Incorporation of this parameter into donor screening protocols may enhance risk stratification and long-term donor safety. Funding: Clinical Revenue Support