Is contralateral exploration of the kidney necessary in patients with Wilms tumor?

Surgical exploration of the contralateral kidney in patients with Wilms tumor is standard practice. The introduction of modern imaging techniques (ultrasound, computerized tomography and magnetic resonance imaging) in place of excretory urography has led to a more accurate definition of intrarenal pathology. Is contralateral kidney exploration still necessary in patients with Wilms tumor?

We reviewed the records of 75 patients from 3 medical centers who were evaluated and treated for Wilms tumor in the last 14 years. All children underwent preoperative excretory urography, computerized tomography, ultrasound and/or magnetic resonance imaging.

Seven bilateral Wilms tumors were diagnosed preoperatively and confirmed surgically, whereas extensive operative exploration of the contralateral kidney in the other 69 patients revealed no additional pathological condition. This concurred with preoperative radiological findings with 100% sensitivity and specificity. Furthermore, 1 month to 12 years of followup (mean 4.3 years) revealed no tumor in the contralateral kidney. The major postoperative complication was small bowel obstruction in 5 patients 15 to 180 days (mean 77.2) after explorative laparotomy.

In all patients preoperative radiological investigation was accurate in excluding bilaterality. With modern imaging techniques and effective chemotherapy extensive contralateral renal exploration may no longer be mandatory for managing Wilms tumor.