Retroperitoneal Fibrosis

Background

• Characterized by the presence of an inflammatory, fibrotic process in the retroperitoneum causing compression of the retroperitoneal structures including the ureters
• In general, the RPF mass centers around the distal aorta at L4 to L5 and wraps around the ureters, leading to hydronephrosis via extrinsic compression on the ureters or interference with ureteral peristalsis.

Etiology

• Idiopathic (70%)
  • Associated with chronic aortitis
• Other identifiable cause (30%)
  • Medications (3):
    1. Methysergide (Sansert) and other ergot alkyloids
    2. β-Blockers
    3. Phenacetin

Pathogenesis

• Unknown but appears to be autoimmune in nature

Diagnosis and evaluation

• Symptoms and signs are usually nonspecific
• Laboratory evaluation may show an elevated ESR, CRP, moderate leukocytosis, anemia, and variable renal insufficiency associated with electrolyte abnormalities
• Although most patients with malignant RPF have a prior history of malignancy, a thorough evaluation for occult malignancy with careful application of imaging studies is necessary
  • The most common malignancy in RPF is lymphoma

Management

• Decompression
  • Patients with hydronephrosis and uremia should be emergently decompressed by either nephrostomy or ureteral stent
    • Ureteral stent placement is usually not difficult to perform in the setting of RPF.
    • Advantages of ureteral stents:
      • Opportunity to perform retrograde pyelograms to evaluate the anatomy
      • Convenience of internal drainage
    • In a critically ill patient with electrolyte abnormalities and little or no urine output, nephrostomy tube placement is favored.
  • After decompression, the patient should be monitored closely for post-obstructive diuresis, renal function status, and appropriate replacement of fluids and electrolytes.
• Medications
  • Primary medical management involves steroid therapy
    • Patients who have evidence of active inflammation—manifested by increased ESR, CRP, leukocytosis, or active inflammation on a biopsy—are more likely to respond to steroid therapy.
  • Use of immunosuppressive agents (azathioprine, mycophenolate mofetil, cyclosporine, cyclophosphamide, and colchicine) is reserved for patients in whom steroid therapy fails; relapses are as high as 50% during steroid tapering
  • Other medications used: medroxyprogesterone acetate, progesterone, and particularly tamoxifen
• Ureterolysis
  • May be performed open or laparoscopically
  • Although hydronephrosis may be unilateral on preoperative assessment, in general the process is bilateral, requiring bilateral ureterolysis.
    • In bilateral ureterolysis, the ureters need to be protected by intraperitonealization or omental wrapping.
    • If ureterolysis is impossible to perform, renal autotransplantation may be performed

Questions

1. Which medications are associated with retroperitoneal fibrosis?

Answers

1. Which medications are associated with retroperitoneal fibrosis?
   1. Methysergide
   2. Ergot
   3. Beta-blockers
   4. Phenacetin

References

• Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, chap 49