Whole and cortical kidney volume predict 5‐year post‐nephrectomy eGFR in Indian living kidney donors. Issue 2 (25th November 2022) - Chanda, Reettika
Abstract: Aim: To study the additional utility of pre‐nephrectomy whole and cortical kidney volumes (WKV, CKV) in predicting long‐term post‐nephrectomy kidney function in Indian living kidney donors (LKDs). Methods: This retrospective cohort study included all LKDs who underwent nephrectomy between 1 January 2006 and 31 December 2015 at our centre, had pre‐nephrectomy height, weight and computed tomography (CT) angiography with arterial and nephrographic phase documented, and 5‐year post‐nephrectomy creatinine values measured. Correlation between body surface area (BSA) adjusted pre‐nephrectomy total CKV, WKV and pre‐nephrectomy CKD EPI eGFR; BSA‐adjusted remnant pre‐nephrectomy CKV (rCKV), WKV (rWKV) and 5‐year post‐nephrectomy CKD EPI creatinine eGFR (5yeGFRCr ); predictors of 5yeGFRCr < 70% of pre‐nephrectomy CKD EPI creatinine eGFR (pre‐eGFRCr ), and an equation to predict 5yeGFRCr from pre‐nephrectomy variables were calculated. Results: A total of 196 LKDs (74% female, mean age 41.7 ± 11.0 years) were included in the study. Total WKV showed higher correlation with pre‐nephrectomy eGFR than CKV, the highest with CKD EPI cystatin eGFR. Remnant WKV showed higher correlation than rCKV with post‐nephrectomy eGFRCr and this increased over time. Older age, lower rWKV or rCKV, higher BSA, and higher pre‐eGFRCr identified LKDs with 5yeGFRCr < 70% of pre‐eGFRCr, with rCKV identifying a higher proportion (4.5%) of such LKDs. A model including rWKV or rCKV predicted 5yeGFRCr better than one including age, gender, BSA and pre‐eGFRCr alone. Conclusion: Inclusion of pre‐nephrectomy remnant CKV and WKV into models for 5yeGFRCr and sub‐optimal post‐nephrectomy adaptation in Indian LKDs improves their accuracy. CKD EPI cystatin eGFR correlates better with functional renal mass. Summary at a Glance: Pre‐nephrectomy whole and cortical kidney volume identify Indian living kidney donors with sub‐optimal renal adaptation 5 years after nephrectomy and improve the accuracy of prediction models for 5‐year post‐nephrectomy CKD EPI creatinine eGFR. CKD EPI cystatin C eGFR has a higher correlation with CT volumes than CKD EPI creatinine eGFR.