Inflammatory bowel disease

Inflammatory bowel diseaseDr. Angus Lee SET 1 General Surgery

Burrill Crohn, an American Gastroenterologist, with his 2 other colleagues first described Terminal ileitis in 1932

Epidemiology of IBDIncidence 2-15/100, 000 Prevalence 40-80/100,000More common in developed countries; higher SESMore common in Jewish population; less common in Asian populationPresentation commonly at younger age ~ 20s; but can occur at any ageFirst degree relative with Crohns : ~ 10% lifetime riskMonozygotic twins: 58% for Crohns; 6% for UC

PathogenesisComplex

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 Crohns but lower risk in UC

How to differentiate Crohns and UC?Direct visualisation by endoscopy

Histological diagnosis

Radiological appearance

Antibodies: anti Saccharomyces cerevisiae (ASCA) for Crohns; antineutrophil cytoplasmic antibody (p- ANCA) for UC Pathological features

6DistributionCrohnsUCSB 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% GI/ Liver secrets. McNally 4th ed

Crohns

ComplicationsUCCrohnsPerforationHaemorrhageToxic megacolonCarcinomaPerforationStrictureFistulaPerianal complicationMalnutrition Vit B12 deficiencyStones: renal; gallbladder

Severity of UC

Medical management: 5- ASADepends 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 hydrocortImmunosuppressive drugsAzathioprine6- mercaptopurineCyclosporinMonoclonal antibody: targettingTNF alpha eg. Infliximab -useful for both ileal and colonic Crohns - high response rate in severe cases and patients with fistulae.

Surgery in IBD70% of Crohns require surgery

Surgery in UC can be potentially curativeIndicationCrohnsUCFailure of medical managementObstructionFistulaeAbscessHaemorrhagePerforationGrowth retardationCancer

Failure of medical managementToxic megacolonHaemorrhagePerforationCancer - 20% third decade - ~ 1% increase of incidence after 10 years of colitis

Surgical objectives for complications of Crohns disease Preoperative Objectives

Maximize or exhaust nonsurgical treatment options prior to surgery

Surgical intervention should be limited to the treatment of symptomatic complications of Crohns 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 malignancyStricturoplasty

FistulaeClassification: Spontaneous vs postoperative Internal vs external

SNAP approach Sepsis; Nutrition; Anatomy; Plan

Choices of operation in UCEmergencyElectiveSubtotal colectomy and ileostomy

Proctocolectomy and permanent ileostomyProctocolectomy and ileal pouch Colectomy and ileal rectal anastomosisProctocolectomy and continent ileostomy

PouchitisCumulative incidence: 15-53% double risk if PSCTreatment: ciprofloxacin and metronidazoleVSL 3 probiotic was shown to be effective in maintaining remission in ~85% of pouchitis