Who really benefits from nephron-sparing surgery?

OBJECTIVE: To analyze the influence of preoperative renal function on postoperative renal outcomes after radical nephrectomy (RN) and nephron-sparing surgery (NSS) for malignancy in patients stratified according to preoperative chronic kidney disease (CKD) stage and surgical extent (NSS vs RN).

PATIENTS AND METHODS: Retrospective review of patients undergoing renal surgery for localized renal masses stratified by surgical extent and preoperative CKD stage based on glomerular filtration rate (GFR) level: stage I (>90 mL/min/1.73 m(2)), stage II (60-89 mL/min/1.73 m(2)), and stage III (30-59 mL/min/1.73 m(2)). Survival analysis for significant renal impairment was based on freedom from the development of new-onset GFR <30 or <45 mL/min/1.73 m(2).

RESULTS: A total of 1306 patients were included in the analysis with preoperative CKD stage I (27.9%), II (52.1%), and III (20.1%); 41.3% and 58.7% underwent NSS and RN, respectively. NSS was associated with a lower annual rate of GFR decline in preoperative CKD stage-I (P = .028) and stage-II patients (P = .018), but not in CKD stage-III patients (P = .753). Overall, 5.0% and 15.0% developed new-onset GFR <30 mL/min/1.73 m(2) and <45 mL/min/1.73 m(2), respectively. There was no difference in the probability of developing significant renal impairment between NSS and RN in CKD stage-I or -III patients, whereas only in CKD stage-II patients was the surgical extent independently associated with development of significant renal impairment (RN: odds ratio, 9.0; P = .042 for GFR <30 mL/min/1.73 m(2) and odds ratio, 2.3; P = .003 for GFR <45 mL/min/1.73 m(2)).

CONCLUSION: Compared with RN, NSS is associated with a lower rate of GFR decline for preoperative CKD stage-I and -II patients, but only CKD stage-II patients demonstrated a decreased risk of developing significant renal impairment.