What is the treatment for retroperitoneal fibrosis?

Treatment of Retroperitoneal Fibrosis

Critical First Step: Establish the Diagnosis

Biopsy is mandatory before initiating any treatment to definitively distinguish benign idiopathic retroperitoneal fibrosis from malignant retroperitoneal sarcoma, as imaging alone cannot reliably differentiate between these entities. 1

• Image-guided core needle biopsy is the preferred diagnostic approach over open surgical biopsy 1
• The differential diagnosis must exclude lymphoma and germ cell tumors, which require completely different treatment paradigms 1
• Never proceed with major surgical resection before establishing histologic diagnosis, as this prevents inappropriate resection of conditions requiring medical rather than surgical management 1

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Treatment Algorithm Based on Diagnosis

For Benign Idiopathic Retroperitoneal Fibrosis

The optimal treatment combines initial urinary decompression, immunosuppressive medical therapy, and selective surgical intervention based on response to medical management.

Step 1: Immediate Urinary Decompression (if obstructive uropathy present)

• Place ureteral DJ stents or percutaneous nephrostomy for acute management of obstructive uropathy causing hydronephrosis 2, 3
• This prevents further renal damage while medical therapy is initiated 2

Step 2: Immunosuppressive Medical Therapy (First-Line)

Initiate combination immunosuppressive therapy with oral prednisolone 1 mg/kg/day plus azathioprine 1 mg/kg/day for 3 months before surgical reevaluation. 3

• Alternative regimens include methylprednisolone pulse therapy combined with azathioprine or penicillamine 4
• Corticosteroid monotherapy for 2 years has shown success in preserving renal function with symptom resolution 5
• Continue immunosuppressive medication for an additional 3 months if complete remission is achieved 3
• Medical therapy alone achieves satisfactory outcomes in 86% of cases, with combination steroid-immunosuppressive therapy effective in 97% 6

Step 3: Surgical Intervention (if medical therapy fails)

Proceed to ureterolysis with intraperitoneal displacement and omental wrapping if stable disease or progression occurs after 3 months of medical therapy. 3

• Combined surgical and medical treatment results in excellent long-term outcomes with only 8% recurrence rate in idiopathic retroperitoneal fibrosis 3
• Continue immunosuppressive medication for 3 months postoperatively in all primary cases 3
• Bilateral ileal ureteral replacement may be necessary in severe cases unresponsive to ureterolysis 3

Step 4: Long-Term Follow-Up

• Lifelong surveillance is required after discontinuation of steroid therapy 5
• Follow-up duration should extend from 6 to 120 months with regular imaging 3

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For Malignant Retroperitoneal Fibrosis (Sarcoma)

Complete surgical resection with negative margins performed by surgeons with sarcoma expertise is the only curative treatment and must be performed at primary presentation. 1, 7

Preoperative Management

• Neoadjuvant radiotherapy (45-50 Gy) is often preferred as it reduces tumor seeding risk and may improve resectability 1, 7
• Consider neoadjuvant chemotherapy when response would facilitate resection or improve symptoms 1
• Preoperative angiography with embolization should be considered for tumors with significant vascular involvement 7

Surgical Approach (Histology-Specific)

For retroperitoneal liposarcomas:

• Extended surgical resection including adjacent viscera is required due to poorly defined margins 1, 7
• Resection often necessitates ipsilateral nephrectomy, hemicolectomy, psoas fascia/muscle resection, and potentially distal pancreatectomy/splenectomy 1, 7

For retroperitoneal leiomyosarcomas:

• Complete tumor resection with involved organs only, preserving adjacent uninvolved organs 1, 7
• Extended resections do not improve outcomes as prognosis is dictated by metastatic disease risk 1, 7

For solitary fibrous tumors:

• Complete resection with negative margins while preserving uninvolved organs 7

Postoperative Management

• Postoperative radiotherapy has limited value following complete resection and carries significant toxicities 7
• Consider boost radiation (10-12.5 Gy IORT for microscopically positive margins, 15 Gy for gross disease) 8

Surveillance

• Cross-sectional imaging at 3-6 month intervals initially, extending to annual after 5 years 1, 7
• Clinical evaluation should accompany all imaging studies 7

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For Secondary Retroperitoneal Fibrosis (post-aortic graft, radiation, prior surgery)

Primary reconstructive surgery is the most promising approach with only 5% recurrence rate. 3

• Ureterolysis with intraperitoneal displacement is the preferred surgical technique 3
• Short external ureteral compression may be managed by endoluminal balloon dilatation 3
• Immunosuppressive therapy has limited role compared to idiopathic cases 3

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Common Pitfalls to Avoid

• Do not perform definitive surgery without tissue diagnosis - this is the most critical error that can lead to inappropriate management of lymphoma, germ cell tumors, or benign inflammatory conditions 1
• Do not rely on imaging characteristics alone to distinguish benign from malignant retroperitoneal processes 1
• Do not discontinue immunosuppressive therapy prematurely in idiopathic cases - continue for full 6 months (3 months initial + 3 months after remission) 3
• Do not perform extended resections for leiomyosarcomas as they do not improve outcomes 1, 7