Nephron-sparing procedures in 11 patients with Wilms' tumor.

PURPOSE

In unilateral Wilms' tumor (WT), tumor nephrectomy is the standard surgical approach, whereas partial nephrectomy (PN) is controversially discussed. The aim of our retrospective study was to show that in selected cases of unilateral WT kidney-sparing operations could be a reasonable alternative to nephrectomy and to discuss the results of patients with bilateral WT treated by tumor enucleation.

MATERIALS AND METHODS

From 1981 to 1998, seven patients with unilateral nephroblastoma (four stage I, one stage III and two stage IV) had tumor resection by PN (five right side, two left side), which was planned when the tumor volume was reduced after 4 to 6 weeks of chemotherapy by at least 50%, when the tumor occupied one pole or was easily resectable, when 50% or more of the kidney tissue remained and when paraaortic lymph nodes were free by intraoperative histological examination. In four patients with bilateral WT (stage V) bilateral tumor enucleation was carried out-except in one patient in whom the contralateral kidney had to been removed because of extension of the tumor via the inferior vena cava to the right atrium. All patients ( n = 11) received pre- and postoperative chemotherapy followed by radiotherapy in four patients.

RESULTS

All patients with unilateral WT ( n = 7) are still alive and disease free (follow-up time: mean 6.6 years, range: 28 months to 11 years) with normal renal function, although two patients with secondary nephrectomy revealed creatinine clearance levels at the lower range. In six patients primary PN was performed successfully. In a stage III tumor patient (intraperitoneal metastasis, free lymph nodes), secondary nephrectomy was necessary due to renal arterial thrombosis 2 days after PN. In one stage IV tumor patient (lung metastasis, free lymph nodes), the primary resection was not far enough away from the tumor margin so that an additional slice of tissue with then tumor-free margins had to be resected. This patient evolved a local relapse 19 months after PN and had to be nephrectomised thereafter. In the group of bilateral WT patients ( n = 4), one child died 2 months after surgery during chemotherapy because of central venous line sepsis. One patient who additionally suffered from inferior vena cava tumor thrombosis extending to the right atrium making nephrectomy of the right kidney necessary developed chronic renal failure 4.7 years postoperatively. The other two stage V tumor patients have creatinine clearance levels within the normal range.

CONCLUSIONS

Kidney-sparing procedures remain the operative approach of choice in patients with bilateral WT, but bear the risk of chronic renal failure when one kidney has to be removed. PN in children with unilateral WT, carried out by an experienced surgeon, is a reasonable alternative to nephrectomy if strict guidelines such as excellent tumor response to preoperative chemotherapy and easy resectability far away from the tumor margins through healthy kidney tissue are followed. Paraaortic lymph nodes must be free of tumor invasion in order to avoid local radiotherapy. PN prevents the patient from having to have dialysis in cases of contralateral nephrectomy resulting from metachronous WT or subsequent renal trauma.