Renal Function Recovery after Nephrectomy or Nephron-Sparing Surgery in Children with Unilateral Renal Tumor.

Introduction Children with unilateral renal tumor (URT) and preoperative renal dysfunction (PRD) may benefit from nephron-sparing surgery (NSS). To test this hypothesis, we studied the outcome of baseline renal function after nephrectomy or NSS among children with URT. Materials and Methods Retrospective records review of children with URT who underwent nephrectomy (25 children) or NSS (11 children) at our institution. We analyzed the estimated glomerular filtration rate (eGFR) changes over time among patients, stratified by both preoperative renal function (with or without PRD) and surgical extent (NSS vs. nephrectomy). The primary end point was evaluation of compensatory recovery of preoperative eGFR after surgery. Only children older than 2 years at surgery were included in the study. Renal dysfunction was defined as an eGFR < 90 mL/min/1.73 m2. Results After nephrectomy or NSS, patients with PRD presented, on average during adolescence, a significant increase in eGFR, whereas patients without PRD presented, on average during adolescence, a stable eGFR. However, after nephrectomy, 5 of 17 (29%) and 7 of 8 (87%) adolescent patients with baseline eGFR ≤ or > 100 mL/min/1.73 m2, respectively, achieved or maintained two-kidney eGFR values (T-KEV) (p = 0.01). After NSS, four adolescent patients with PRD and seven without PRD achieved or maintained T-KEV. Conclusion The majority of children with URT and low baseline eGFR present with an impaired renal function recovery after nephrectomy and may benefit from NSS. Collaborative studies are needed to support present findings.