Renal salvage procedures in patients with synchronous bilateral Wilms' tumors: a report from the National Wilms' Tumor Study Group.

Synchronous bilateral Wilms' tumor accounts for 4% to 6% of all Wilms' tumors. Renal salvage procedures (partial nephrectomy and enucleation) have been recommended to conserve renal parenchyma. The objective of this study was to review the results of renal salvage operations performed in children who had bilateral neoplasms. The authors reviewed the records of 98 children enrolled in the Fourth National Wilms' Tumor Study who had synchronous bilateral tumors and underwent renal salvage procedures. One hundred thirty-four kidneys were managed with renal salvage procedures. Complete excision of gross disease was accomplished in 118 (88%) of the 134 kidneys. Local tumor recurrence in the remnant kidney or tumor bed occurred in 11 cases (8.2%). Overall, 72% of the kidneys were preserved, and the 4-year survival rate was 81.7%. The surgical morbidity after a salvage procedure was comparable to that of a complete nephrectomy in patients with unilateral Wilms' tumor. Although the incidence of positive surgical margins is worrisome, it did not invariably lead to local recurrence in the remnant kidney or the tumor bed.