Nephron sparing surgery for Wilms tumor--where is the future?

Bench surgery with autotransplantation for bilateral Wilms tumor-A feasible technique for renal sinus invasion

Purpose

Bilateral Wilms tumor (BWT) with renal sinus invasion requires extremely difficult surgical care. This study presents an alternative strategy for tumor removal while at the same time preserving the renal parenchyma.

Materials and methods

In total, 9 cases of synchronous BWT were admitted to our hospital between May 2016 to Aug 2020. We retrospectively reviewed the clinical data, surgical technique, and functional and oncological outcomes of these cases.

Results

The 9 cases included 3 males and 6 females, with a median age of 12 months at surgery (range 7-40). A total of 14 kidney units had renal sinus invasion (77.8%), whereas multifocal neoplasms were observed in 7 units (38.9%). The local stage distribution revealed 1 kidney with stage I, 10 kidneys with stage II, and 7 kidneys with stage III. Nephron-sparing surgery was performed on 15 kidney units (83.3%), among which 13 (72.2%) underwent bench surgery with autotransplantation (BS-AT), whereas 2 (11.1%) were subjected to tumor enucleation in vivo. Urinary leakage was the most prevalent postoperative complication. We observed negative margins. During the mean follow-up of 28.4 months, 2 patients (22.2%) succumbed from sepsis and renal failure, respectively, whereas the other 7 (77.8%) survived without recurrence. Survivors experienced an estimated glomerular filtration rate of 81 ± 15.4 ml/(min × 1.73 m²). The endpoint renal volume of 9 renal units receiving BS-AT significantly increased (P = 0.02).

Conclusions

In summary, the surgical management of bilateral Wilms tumor requires meticulous operative approach and technique. Besides, BS-AT provides a viable alternative to nephron-sparing surgery for BWT patients with renal sinus invasion.

Nephron-sparing surgery in bilateral Wilms' tumor: A report of two cases

Nephron-sparing surgery (NSS) has been proposed by many as an alternative to bilateral nephrectomies and renal replacement therapy in bilateral Wilms’ tumor (BWT). NSS is not without significant recurrence, morbidity, and mortality. Long-term follow-up, especially with regard to the renal function, remains lacking. Preoperative computed tomography angiogram can help prepare a roadmap for NSS but can underestimate the salvageable parenchyma due to compression of normal adjacent parenchyma. Intraoperative ultrasound can delineate the boundary of surgical margin and help achieve negative margins. We present two cases of BWT, aged 7 and 13 months, managed with neoadjuvant chemotherapy followed by bilateral NSS and adjuvant chemotherapy and report the follow-up of the same. We also explore the role of preoperative imaging and intraoperative ultrasound in the management. Both patients are alive without recurrence at a follow-up of 12 and 8 months.

Oncology: the role of partial nephrectomy in Wilms tumor

Wilms tumor represents the most common pediatric renal malignancy and the fourth most common childhood cancer overall. Overall survival from Wilms tumor has increased to over 90 % secondary to multidisciplinary therapy and multi-institutional cooperative group trials. Recent therapeutic focus has shifted to reduction in treatment morbidity and renal preservation while maintaining the high survival rates. Partial nephrectomy is an integral component of the multimodal treatment protocols for Wilms tumor patients with bilateral disease, solitary kidney, or predisposing syndromes. Recent consideration has been given to utilization of nephron sparing surgery (NSS) in carefully selected patients with nonsyndromic unilateral Wilms tumor. While long-term, prospective data in this subgroup of patients is not yet available, case series demonstrate comparable oncologic outcomes after partial versus radical nephrectomy. The relative rarity of Wilms tumor, especially those amenable to upfront partial nephrectomy, presents a challenge to conducting controlled trials.

The use of Tachosil as hemostatic sealant in nephron sparing surgery for Wilms tumor: preliminary observations

BACKGROUND

TachoSil, which is an absorbable collagen sponge coated with human fibrinogen and thrombin, has proven to enhance hemostasis and promote optimal wound healing in adults undergoing nephron sparing surgery (NSS). We report our preliminary experience using this hemostatic agent during NSS in children.

METHODS

Prospective analysis of 3 patients with Wilms tumor (synchronous bilateral in one) undergoing NSS at our institution over an 18-month period. Primary outcome measures were intraoperative bleeding control and surgery-related postoperative sequelae.

RESULTS

Overall, 4 kidneys underwent 5 NSS procedures, which included 3 partial nephrectomies and multiple tumor excisions performed on another kidney at initial and second-look surgery. After control of major bleeding and suturing of the collecting system, which was entered during 2 of the 5 NSS procedures, TachoSil was applied to the parenchymal surface of the kidney, achieving immediate hemostasis. All NSS procedures were performed without hilar clamping, drainage or stent placement. None of the patients required blood transfusion. Small perirenal fluid collections were documented postoperatively, and all spontaneously resolved within 4 weeks of surgery.

CONCLUSION

In children undergoing NSS, TachoSil represents an effective and safe tool for control of mild to moderate bleeding, and also facilitates sealing and wound dressing.