Trends in the use of of nephron-sparing surgery (NSS) at an Australian tertiary referral centre: an analysis of surgical decision-making using the R.E.N.A.L. nephrometry scoring system

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Nephron‐sparing surgery (NSS) is increasingly recognised as a preferred form of management for the incidentally detected small renal mass (SRM). Within the context of equivalent oncological outcomes, patients treated by NSS may have a survival advantage over those treated by radical nephrectomy (RN) through a reduced risk of chronic kidney disease and its associated cardiac morbidity. Despite this, according to Medicare data from the USA, a disproportionate number of patients with SRMs continue to be treated with RN instead of NSS. Similar data from Australia are not yet available. The present study explores the evolving management of SRMs at an Australian tertiary centre over a 5‐year period. It utilises the R.E.N.A.L. Nephrometry Score to assess how lesion complexity has influenced surgical decision‐making and charts the increasing use of NSS in the management of low‐complexity renal masses at our centre.

OBJECTIVE

• ? To examine recent trends in the use of nephron‐sparing surgery (NSS) at our centre. Specifically, we sought to examine the process of surgical decision‐making by applying the R.E.N.A.L. nephrometry scoring system to assess the complexity of lesions for which surgery was undertaken.

PATIENTS AND METHODS

• ? We performed a retrospective review of renal masses treated by surgery from January 2005 to December 2009, including 79 RN and 70 NSS.
• ? CT images were available for analysis in 50 patients within each group.
• ? Lesions were scored on the basis of their complexity using the R.E.N.A.L. nephrometry scoring system developed by Kutikov and Uzzo.

RESULTS

• ? There was no difference in age between patients undergoing RN and NSS (median age 61 vs 60 years).
• ? RN was performed for significantly larger lesions (mean [sd ] 68 [9] vs 29 [2] mm, P < 0.05) of predominantly moderate and high complexity (12% low, 56% moderate, 32% high).
• ? NSS was primarily used for low‐complexity lesions, but included four (8%) moderate‐complexity lesions in the final 2 years of the study.
• ? The use of NSS increased from 28.6% of cases in 2005 to 60.0% of cases in 2009, which mirrored the increase in the proportion of operations performed for low‐complexity lesions (22.2% low‐complexity in 2005 to 70.6% in 2009, P < 0.01 for trend).

CONCLUSIONS

• ? The increasing use of NSS at our institution mirrored the increasing treatment of low‐complexity renal lesions.
• ? This may reflect an increased detection and referral of such lesions, or a shift towards treatment of lesions that in the past would have been under surveillance.
• ? Practice at our centre reflects a shifting paradigm towards preferential use of NSS for the treatment of suitable renal masses.