Wilms’ Tumor and Neuroblastoma

Chapter 85 Wilms’ Tumor and Neuroblastoma



Todd A. Ponsky, MD



Wilms’ Tumor



INTRODUCTION


Nephroblastoma, also known as Wilms’ tumor after Max Wilms who described seven cases in 1899, is the most common intra-abdominal cancer in children. Wilms’ tumor represents 6% of all pediatric cancers and the incidence is 8 cases per 1 million children younger than 15 years of age or 1 in 10,000 infants.1 Seventy-five percent of cases occur in children under 5 years of age, and the peak incidence is 2 to 3 years of age.2


Surgical therapy for Wilms’ tumor was first described in 1877, with poor outcomes. Over the next 100 years, the operative strategy for Wilms’ tumor was modified to include the addition of chemotherapy and, occasionally, radiation. Furthermore, a cooperative study of several groups called the National Wilms’ Tumor Study (NWTS) developed treatment standards that have improved overall survival to approximately 95.6% for stage 1 tumors.3


Children suspected of having a renal mass should undergo an abdominal ultrasound (US). Besides confirming the presence of the tumor, abdominal US is necessary to assess contralateral disease and evidence of caval invasion. Chest x-ray should be performed to assess for metastatic disease.



INDICATIONS



• Renal mass on computed tomography (CT) or US scan


OPERATIVE STEPS



Step 1 Position patient with affected side elevated on roll

Step 2 Transverse abdominal incision

Step 3 Thorough abdominal exploration, reflection of colon off of tumor

Step 4 Exploration of contralateral kidney

Step 5 Ligation of hilar vessels

Step 6 Division of lateral attachments

Step 7 Separation of kidney from adjacent organs

Step 8 Perinephric lymph nodes dissection

Step 9 Ureter ligation

Step 10 Removal of kidney and abdominal wall closure


OPERATIVE PROCEDURE



Incision



Poor Exposure/Tumor Spillage


Prior to incision, the involved side should be slightly elevated with a roll. The optimal incision for Wilms’ tumor is a transverse abdominal incision, which offers the best exposure. A large incision is crucial in order to avoid excessive tumor manipulation and potential tumor spill. Flank incisions offer suboptimal exposure.



• Consequence


Poor exposure may lead to excessive tumor manipulation, which may lead to tumor rupture and spillage. Spillage of tumor will automatically upgrade the tumor to stage 3, which will require postoperative radiation and the addition of doxorubicin (Adriamycin) to the chemotherapy regimen.

Grade 4 complication


• Repair


If the initial incision offers poor exposure, it would be prudent to extend the incision rather than struggle. Once spillage occurs, there is no remedy.


• Prevention


Poor exposure can be prevented by elevating the affected side with a roll and creating a generous transverse incision.


Exploration of the Contralateral Kidney



Contralateral Wilms’ Tumor Identified Intraoperatively


Although controversial, many surgeons will explore the contralateral kidney prior to nephrectomy. Gerota’s fascia is incised, the kidney is palpated and visually inspected on all sides, and any lesions are biopsied.



• Consequence


Occasionally, contralateral tumor that was not visualized on preoperative studies is identified intraoperatively. This may require a complete change in the anticipated management.

Grade 3 complication


• Repair


If a mass is identified in the contralateral kidney intraoperatively, it should be biopsied. If the biopsy confirms Wilms’ tumor, the operation should be aborted and neoadjuvant chemotherapy should be performed.


• Prevention


Preoperative US and CT scans should significantly reduce the chance of a contralateral tumor being identified intraoperatively.


Renal Hilum Ligation



Ligation of the Contralateral Vessels


Sometimes, the large renal mass encroaches on the hilum so much that it thins out the inferior vena cava (IVC) and the ipsilateral renal artery and vein and lifts the contralateral renal vessels up, making them susceptible to injury or ligation (Fig. 85-1).


image

Figure 85-1 Hidden anatomy. When a right renal mass extends into the hilum, it flattens the short right renal vein and lifts up the longer left renal vein. This puts the latter at risk for being mistaken for the right renal vein and ligated inadvertently.



• Consequence


Ischemia of the contralateral normal kidney.

Grade 4 complication


• Repair


Repair of the injury can be attempted. Bypass of the contralateral renal vessels might be necessary if the injury was crushing or extensive.


• Prevention


It is essential to completely identify both sets of renal vessels and their junction with the IVC and aorta to avoid inadvertent injury to the contralateral vessels.

Related posts:

  1. Isolated Limb Perfusions and Extremity Amputations
  2. Traumatic Brain Injury
  3. Open Inguinal Hernia Repair with Plug and Patch Technique
  4. Bronchial and Vascular Sleeve Lobectomy

Stay updated, free articles. Join our Telegram channel
Tags:
Jun 21, 2017 | Posted by in GENERAL SURGERY | Comments Off on Wilms’ Tumor and Neuroblastoma

Full access? Get Clinical Tree
Get Clinical Tree app for offline access