Overview
Definition:
Radical nephrectomy for Wilms tumor is the surgical removal of the entire kidney, adrenal gland, perinephric fat, and involved lymph nodes
It is the primary treatment for localized Wilms tumor and often the initial step in management.
Epidemiology:
Wilms tumor, or nephroblastoma, is the most common primary malignant kidney tumor in children, accounting for about 90% of childhood renal neoplasms
Incidence is approximately 1 in 10,000 live births
It predominantly affects children under 5 years of age.
Clinical Significance:
Early and complete surgical resection of Wilms tumor is crucial for achieving cure and minimizing recurrence
Understanding the principles of radical nephrectomy, including its indications, technique, and potential complications, is vital for surgical residents preparing for DNB and NEET SS examinations.
Indications
Surgical Indications:
Primary treatment for localized, resectable Wilms tumor
Staging surgical exploration to assess resectability and stage the disease
Management of recurrent or residual tumor after initial treatment
Occasionally indicated for diagnosis in cases where biopsy is not feasible or definitive.
Staging Considerations:
The extent of surgery influences the surgical stage of the tumor
Factors like tumor rupture, positive margins, and nodal involvement are critical for staging and subsequent treatment planning.
Preoperative Assessment:
Thorough pre-operative evaluation including imaging (ultrasound, CT scan), blood work (CBC, LFTs, renal function tests), and discussion with the pediatric oncology team is mandatory
Pre-treatment chemotherapy for very large or bilateral tumors may alter surgical approach.
Surgical Management
Preoperative Preparation:
Adequate hydration and pain management
Prophylactic antibiotics may be administered
Careful anesthetic management to avoid tumor manipulation and potential seeding
Patient positioning to optimize surgical access.
Operative Technique:
Laparoscopic or open approaches are used
Open approach (subcostal or thoracoabdominal incision) is often preferred for large tumors or suspected extensive disease
Careful dissection starting from the hilum, ligating renal artery and vein first to minimize tumor embolization
Resection of Gerota's fascia with the kidney
En bloc removal of the kidney, adrenal gland, and surrounding lymph nodes
Careful assessment for bilaterality and contralateral kidney involvement.
Lymph Node Dissection:
Systematic sampling or complete dissection of ipsilateral para-aortic, renal hilar, and possibly trans-diaphragmatic lymph nodes, depending on tumor extent and institutional protocols
Crucial for staging and prognosis.
Intraoperative Findings:
Assessment of tumor size, involvement of adjacent structures, and presence of distant metastases
Documentation of any tumor spillage or rupture, which significantly impacts staging and prognosis.
Postoperative Care
Pain Management:
Effective analgesia is essential, often multimodal, including IV opioids and NSAIDs
Epidural analgesia may be considered for open procedures.
Fluid And Electrolyte Balance:
Close monitoring of intake and output, serum electrolytes, and renal function
Replacement of losses from drains or insensible losses
Adequate fluid resuscitation.
Monitoring For Complications:
Vigilant monitoring for bleeding, infection, ileus, and urine leak
Regular vital sign assessment and abdominal examination.
Nutritional Support:
Early initiation of oral feeding as tolerated
If prolonged ileus or inability to feed, parenteral nutrition may be required
Nutritional assessment to ensure adequate protein and calorie intake.
Discharge Planning:
Education of parents regarding wound care, activity restrictions, signs of complications, and follow-up appointments
Coordination with the pediatric oncology team for chemotherapy or radiotherapy as indicated.
Complications
Early Complications:
Hemorrhage from the renal vessels or dissected surfaces
Wound infection or dehiscence
Bowel ileus
Urine leak or fistula formation
Adrenal insufficiency (if adrenal gland is resected and contralateral gland is compromised)
Pulmonary complications (atelectasis, pneumonia).
Late Complications:
Chronic kidney disease or renal insufficiency (especially if contralateral kidney is also compromised or absent)
Bowel obstruction due to adhesions
Post-nephrectomy pain syndrome
Increased risk of cardiovascular disease later in life
Secondary malignancies (rare).
Prevention Strategies:
Meticulous surgical technique to control bleeding and avoid injury to adjacent organs
Careful handling of tissues to minimize contamination
Judicious use of drains
Early mobilization and feeding postoperatively
Prophylactic antibiotics and appropriate wound closure techniques.
Prognosis
Factors Affecting Prognosis:
Stage of the tumor at diagnosis
Histological subtype (favorable vs
unfavorable)
Presence of tumor rupture or spill
Adequacy of surgical resection (negative margins)
Response to neoadjuvant and adjuvant chemotherapy
Presence of bilateral disease or other genetic syndromes.
Outcomes:
With modern multidisciplinary management, the overall survival rate for Wilms tumor is over 90%
Prognosis is significantly influenced by the presence of unfavorable histology or advanced stage.
Follow Up:
Regular follow-up is crucial, typically involving clinical examination, abdominal ultrasound, and chest X-ray at intervals dictated by the stage and histology
Long-term surveillance for recurrence, contralateral tumor development, and late effects of treatment is recommended
Surveillance imaging protocols vary by risk stratification.
Key Points
Exam Focus:
Remember the "classic triad": abdominal mass, hematuria, hypertension
Know the stages of Wilms tumor (SIOP and NWTSG systems)
Prioritize early ligation of renal vessels
Identify signs of tumor rupture and its prognostic implications
Understand the role of neoadjuvant chemotherapy for bilateral tumors or very large tumors.
Clinical Pearls:
Always palpate for a mass with extreme gentleness to avoid tumor dissemination
Consider Wilms tumor in any child with a palpable abdominal mass, especially with hematuria
Bilateral Wilms tumors require a different surgical strategy, often involving bilateral partial nephrectomies if possible
Ligate the renal artery before the vein to reduce venous backflow and potential tumor embolization.
Common Mistakes:
Failure to consider Wilms tumor in the differential diagnosis of pediatric abdominal masses
Inadequate surgical resection leading to positive margins
Incomplete lymph node assessment
Aggressive palpation of the tumor
Delay in initiating adjuvant therapy.