SAN DIEGO, CA USA (UroToday.com) - Limitations of serum creatinine (SCr) to estimate GFR, especially in the blind range of 60-90 ml/min/1.73m2, are well established. This may significantly impact surgeon’s ability to monitor renal function and the ability to detect early development of CKD-III after renal surgery.
Dr. Marianne Schmid and colleagues presented a comparison of SCr and serum Cystatin C (SCysC) use and their ability to predict GFR in this important range of transition from CKD II to CKD III. Dr.Schmid evaluated 31 patients who underwent partial nephrectomy (PN) or radical nephrectomy (RN) and had preoperative GFR > 60 ml/min/1.73m2. GFR was estimated pre-operatively, on the first post-operative day, and one year after the intervention using SCr (eGFR) and SCysC (cGFR). They observed a greater decrease in GFR, for both methods, in patients who underwent RN vs. partial nephrectomy (PN). Elevations of both SCr and SCysC demonstrated statistically significant association between their respective elevations on post-operative day one and in one year (p < 0.001 and p=0.02). In patients with SCr in the blind range, development of CKD-III at one year was seen in 55% and 57% after RN and PN, respectively, based on SCr, while no CKD-III was detected if SCysC was used. Correlation coefficients were superior for SCysC to cGFR (r2=0.99) vs. SCr to eGFR (r2=0.62) in RN and PN (r2=0.99 vs. r2=0.49).
In summary, this study demonstrated a protective effect of PN on development of CKD-III and the superiority of GFR based on SCysC in monitoring renal function, especially in the creatinine-blind range. This may allow for a more accurate detection of early development of CKD-III post-operatively.
Presented by Marianne Schmid, Brigitte Schwaiger, Werner Tenschert, Marc Shaffu, Rana Thabaz, Jessica Langetepe, Sascha Ahyai, Christian Eichelberg, Margit Fisch, and Felix KH Chun at the American Urological Association (AUA) Annual Meeting - May 4 - 8, 2013 - San Diego Convention Center - San Diego, California USA
Reported for UroToday.com by Serge Ginzburg, MD