Small Intestine: Radiation Enteritis

Definition

• Radiation Therapy Induced Injury & Inflammation of the Small & Large Intestine
• Initial Changes Typically Resolve Over a Few Weeks but Can Become Chronic

Causes

• Acute Enteritis: Direct Inflammation
• Chronic Enteritis: Obliterative Arteritis of Submucosal Vessels

Basics

• Most Sensitive Layer: Mucosal Layer
• Risk Factors:
  • Radiation Dose & Duration
  • Combined Chemotherapy
  • Diabetes
  • Underlying Vascular Disease

Factors to Reduce Risk

• ACE Inhibitors & Statins
• Operative Attempts:
  • Tissue Expanders
  • Absorbable Mesh
  • Close Peritoneum Over Pelvic Floor
  • Uterus Retroversion
  • Omental Sling for Complete Exclusion of the Small Bowel
• Possible Options:
  • Amifostine – Most Effective Medication to Protect Intestine from Free Radical Damage
  • Probiotics

Presentation

• Bloating & Diarrhea
• Abdominal Pain
• Nausea & Vomiting
• Ulceration
• Fibrosis & Stricture
• Fistula Formation
• Stasis & Bacterial Overgrowth (Blind Loop Syndrome)
• Impaired Absorption & Malnutrition

Diagnosis

• Dx: CT/MRI or Endoscopy & Bx

Treatment

• Basic Tx: Conservative (Dietary Modifications & Antidiarrheals)
• Stricture/SBO:
  • Preferred Approach: Resection
    • Will Recur After Adhesiolysis or Stricturoplasty
  • If Limited Intestinal Reserve: Stricturoplasty
  • Consider Bypass for Massive Adhesions