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 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 Crohn’s : ~ 10% lifetime

riskMonozygotic twins: 58% for Crohn’s; 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 Crohn’s but lower risk in UC

How to differentiate Crohn’s 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

Distribution

Crohn’s UCSB 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

Crohn’s

ComplicationsUC Crohn’s

PerforationHaemorrhageToxic megacolonCarcinoma

PerforationStrictureFistulaPerianal complicationMalnutrition Vit B12 deficiencyStones: renal;

gallbladder

Severity of UC

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 drugsAzathioprine6- mercaptopurineCyclosporinMonoclonal antibody: targettingTNF alpha eg. Infliximab -useful for both ileal and colonic Crohn’s - high response rate in severe cases and

patients with fistulae.

Surgery in IBD

70% of Crohn’s require surgery

Surgery in UC can be potentially curative

IndicationCrohn’s UCFailure of medical

managementObstructionFistulaeAbscessHaemorrhagePerforationGrowth retardationCancer

Failure of medical management

Toxic megacolonHaemorrhagePerforationCancer - <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

Stricturoplasty

FistulaeClassification: Spontaneous vs postoperative Internal vs external

SNAP approach Sepsis; Nutrition; Anatomy; Plan

Choices of operation in UCEmergency ElectiveSubtotal colectomy and

ileostomyProctocolectomy and

permanent ileostomyProctocolectomy and

ileal pouch Colectomy and ileal

rectal anastomosisProctocolectomy and

continent ileostomy

Pouchitis

Cumulative incidence: 15-53%

double risk if PSCTreatment: ciprofloxacin and

metronidazoleVSL 3 probiotic was shown

to be effective in maintaining remission in ~85% of pouchitis