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Inflammatory bowel disease. Dr. Angus Lee SET 1 General Surgery. Burrill Crohn , an American Gastroenterologist, with his 2 other colleagues first described “Terminal ileitis” in 1932. Epidemiology of IBD. Incidence 2-15/100, 000 Prevalence 40-80/100,000
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Inflammatory bowel disease Dr. Angus Lee SET 1 General Surgery
BurrillCrohn, an American Gastroenterologist, with his 2 other colleagues first described “Terminal ileitis” in 1932
Epidemiology of IBD • Incidence 2-15/100, 000 • Prevalence 40-80/100,000 • More common in developed countries; higher SES • More common in Jewish population; less common in Asian population • Presentation commonly at younger age ~ 20s; but can occur at any age • First degree relative with Crohn’s : ~ 10% lifetime risk • Monozygotic twins: 58% for Crohn’s; 6% for UC
Pathogenesis • Complex • Immunological • Genetic and environmental factors • eg. IBD1 gene encodes NODS2 which regulates intestinal epithelial cells immunity has been implicated • Role of smoking: increases risk 2x in Crohn’s but lower risk in UC
How to differentiate Crohn’s and UC? • Direct visualisation by endoscopy • Histological diagnosis • Radiological appearance • Antibodies: anti – Saccharomycescerevisiae (ASCA) for Crohns; antineutrophilcytoplasmic antibody (p- ANCA) for UC
Distribution Crohn’s UC • SB alone ~30-35% • Colon alone ~ 25-35% • Both ~ 30-50% • Perianal ~50% • Stomach and duodenum 5% • Rectum 50% • Proctosigmoid 30% • Extending beyond splenic flexure 20%
Complications UC Crohn’s • Perforation • Haemorrhage • Toxic megacolon • Carcinoma • Perforation • Stricture • Fistula • Perianal complication • Malnutrition • Vit B12 deficiency • Stones: renal; gallbladder
Medical management: 5- ASA • Depends on extent of disease and severity • 5-aminosalicylate (5- ASA) eg. Sulfasalazine; mesalazine; olsalazine • Sulfasalazine: azo bond to sulfapyridine; bond broken down by colonic bacteria; therefore releasing active sulfasalazine • Side effects relate to sulphonamide component • Olsalazine: two 5 ASA • Mesalazine: enteric coating of 5 ASA; coating dissolves in TI • Distal disease --- 5 ASA enema/ suppository (enema can only reach up to splenic flexure at most) • More extensive disease --- oral preparation
Use of steroid • Route: PR suppository; enema; foam; oral; IV • Generally effective in inducing remission; not so effective in maintaining remission • Moderate cases: oral steroid • Severe cases: IV hydrocort
Immunosuppressive drugs • Azathioprine • 6- mercaptopurine • Cyclosporin • Monoclonal antibody: targettingTNF alpha eg. Infliximab -useful for both ileal and colonic Crohn’s - high response rate in severe cases and patients with fistulae.
70% of Crohn’s require surgery • Surgery in UC can be potentially curative
Indication Crohn’s UC • Failure of medical management • Obstruction • Fistulae • Abscess • Haemorrhage • Perforation • Growth retardation • Cancer • Failure of medical management • Toxic megacolon • Haemorrhage • Perforation • Cancer - <1% from 10 years of onset - 10-15% second decade - >20% third decade - ~ 1% increase of incidence after 10 years of colitis
Surgical objectives for complications of Crohn’s disease Preoperative Objectives • Maximize or exhaust nonsurgical treatment options prior to surgery • Surgical intervention should be limited to the treatment of symptomatic complications of Crohn’s disease • Evaluate nutritional status prior to surgery • Consider supplemental nutrition to improve nutritional parameters prior to surgery Intraoperative Objectives • Spare bowel length • Utilize alternative strategies to resection when appropriate to preserve sufficient length of the remaining bowel; minimize short bowel syndrome • Preserve ileocaecal valve if possible • Biopsy any suspicious ulcers or mucosa for malignancy
Fistulae • Classification: Spontaneous vs postoperative Internal vs external • SNAP approach Sepsis; Nutrition; Anatomy; Plan
Choices of operation in UC Emergency Elective • Subtotal colectomy and ileostomy • Proctocolectomyand permanent ileostomy • Proctocolectomy and ileal pouch • Colectomy and ileal rectal anastomosis • Proctocolectomy and continent ileostomy
Pouchitis • Cumulative incidence: 15-53% • double risk if PSC • Treatment: ciprofloxacin and metronidazole • VSL 3 probiotic was shown to be effective in maintaining remission in ~85% of pouchitis