Abstract

Introduction: Partial nephrectomy (PN) is now commonplace for T1a small renal mass lesions. Nephrometry scores allow the planning of operations to quantify difficulty.  A small volume of information about nephrometry scores predicting renal function changes exists.  We assessed whether RENAL nephrometry scores can contribute to operative planning by predicting post-operative glomerular filtration rate (GFR) changes.

Methods: Retrospective data of 45 patients, was collected from robot assisted PN between 2015 – 2020. RENAL score, calculated from pre-operative CT imaging and blood results collected from local pathology platforms, serial values were documented for pre-operative, day 1, 2, 3 and >30 days post-op. Our definition of post-operative chronic kidney disease (CKD) was failure of creatinine to return to within 10% of baseline.

Results: There were 3 distinct data groups; (A) no creatinine change, (B) post-op creatinine change with no CKD, and (C) new CKD.  Average nephrometry scores for Groups A, B and C were 5.0, 5.5 and 7.7 respectively. Analysis showed an average creatinine percentage change for  Group A: 0.3%,  Group B: 7.35%, Group C: 25.8%. Distance to sinus, relation to the polar lines and endophytic location were individually associated to post-operative CKD, independent of each other.

Conclusion: Clear correlation between overall nephrometry scores and post-operative renal function, with each RENAL component independently impacting creatinine change. These were independent of warm ischaemic time and other impact factors such as comorbidity. This will help identify patients more at risk of end-stage renal failure as well as those patients in whom partial nephrectomy may not be of benefit.

Additional Information

This presentation was given at the SES 2020 online conference, 4 July 2020.