The performance of three estimates of glomerular filtration rate before and after live donor nephrectomy

Abstract

Summary Serum creatinine‐based estimates of glomerular filtration rate (GFR) are inaccurate in healthy individuals. Therefore, their use in assessment prior to live donor nephrectomy has been restricted. There are less data on their use postdonor nephrectomy. This study assessed three GFR estimates against Cr51 EDTA radioisotope GFR (iGFR) in the same cohort of patients before and after donor nephrectomy. A total of 206 patients underwent iGFR measurement prior to donor nephrectomy and this was repeated in 187 patients 6–8 weeks postsurgery. The iGFR was compared with the modification of diet in renal disease (eGFR), Cockcroft–Gault (cgGFR) and Mayo Clinic equation (mcGFR) estimates of GFR. Preoperatively, all GFR estimates performed poorly against iGFR; however, mcGFR provided the most reliable estimate. The eGFR underestimated iGFR by 23.60 ± 16.43 ml/min/1.73 m2, cgGFR by 15.54 ± 18.13 ml/min/1.73 m2 and mcGFR overestimated by 0.72 ± 18.11 ml/min/1.73 m2. Postdonation, all estimates again performed poorly, but eGFR and mcGFR outperformed cgGFR. The eGFR underestimated iGFR by 9.13 ± 10.11 ml/min/1.73 m2, mcGFR by 9.44 ± 13.80 ml/min/1.73 m2 and cgGFR overestimated by 6.42 ± 14.49 ml/min/1.73 m2. No GFR estimate performed sufficiently well to supersede iGFR measurement prior to donor nephrectomy. Performance postdonation was little better. In addition, there was no correlation between fall in iGFR and fall in GFR estimates postdonation.

Does preserved kidney volume predict 1 year donor renal function after laparoscopic living donor nephrectomy?

“…However, previous studies have shown that estimated GFR was not accurate for subjects with normal renal function. The MDRD formula can underestimate GFR by between 9 and 29 mL/min in a kidney donor population . Also, the lack of long‐term follow up in the present study represents an additional limitation, as other risk factors, such as cardiovascular events, are not considered.…”

“…The MDRD formula can underestimate GFR by between 9 and 29 mL/min in a kidney donor population. [14][15][16] Also, the lack of long-term follow up in the present study represents an additional limitation, as other risk factors, such as cardiovascular events, are not considered.…”

Renal function and cardiovascular outcomes after living donor nephrectomy in the UK: quality and safety revisited

“…We chose not to rely on an eGFR before LDN, as regardless of methodology these techniques are known to underestimate the true GFR . This is not a surprise as the MDRD method, was originally generated using GFR measurements in a population of patients with established CKD, most with GFRs of <60 mL/min/1.73 m 2 .…”

Change in renal function following laparoscopic donor nephrectomy using 99 mTc-diethylenetriaminepentaacetic acid scan

“…The MDRD equation can underestimate GFR by between 9 and 29 mL/min in a kidney donor population [10][11][12]. We found that donors with CKD postoperatively actually had good renal function.…”

“…In healthy populations or in subjects with stage I chronic kidney disease (CKD), performance of these equations is poor with considerable systematic underestimation of true GFR and low accuracy [10][11][12].…”