ULCERATIVE COLITIS


DEFINITION
A chronic idiopathic bowel disease which is characterized by inflammatory changes to the mucosa of the colon, with a clinically variable course of remissions and relapses, as well as extra-intestinal manifestations.

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INCIDENCE
Smoking appears to decrease risk in favour of Crohn's
See Crohn's for general IBD risk factors
- Most common in teens - twenties
- Second peak at 40-60y
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AETIOLOGY

Idiopathic
Implicated factors:
- genetics: weak; family hx only in 10%; also 10% identical twin concordance cf 3% fraternal
- post-infectious agents?
 - immunological; e.g. IL imbalance; IL-2 deficiency?
Diet and psychological factors probably not important in relapses
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BIOLOGICAL BEHAVIOUR

Pathology

Inflammatory changes start in rectum and moves continuously proximally;
- no SB disease except occasional backwash ileitis
The lesion is characterised by mucosal / submucosal inflammation (serosal surface is normal)
In the active phase, the mucosa is reddened with a granular surface, with loss of haustra in chronic disease
- islands of regenerating mucosa protrude outwards as pseudopolyps.
Microscopically: there are crypt abscesses, diffuse mononuclear infiltrate, loss of goblet cells
- and epithelial dysplasia (also metaplasia, eg Paneth cells) may progress to cancer.

Natural History
At first presentation, 25% of patients have total colitis (poor sign), 50% have left-sided colitis and 25% have proctitis only.
Sometimes the first attack is the last but 97% will have a relapse in next 10 years
- 60% have mild disease
- 30% require total colectomy;
Typically involves disease flares followed by periods of relative remission.

Extra-intestinal manifestations are more marked than in Crohn's, and may be immune-complex mediated.

Malignancy
Increased risk of colorectal malignancy
Associated with duration and risk
- low in first 8-10y
- increases 1-2% annually therafter.
- 30 years of UC = 10% risk
Occurs in a different pathway, not in polyps
Surveillance annually after 8-10y
- if dysplasia, proctocolectomy (low grade = 20% risk or a cancer; high-grade = 50% risk).

Extra-intestinal
Associated with migratory polyarthritis, sacroiliitis, ank spond, uveitis, hepatic involvement and skin lesions.
Also primary sclerosing cholangitis
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MANIFESTATIONS

Symptoms
Local
Spectrum from mild to severe.
Diarrhoea (often with blood and stringy mucus), frequent bowel motions, tenesmus, LLQ discomfort
- first presentation can be to ED due to bleeding / fluid and electrolyte loss.
- often exacerbated by stress.

Systemic
Fever, malaise, weight loss

Extra-intestinal
Large joint polyarthropathy (20%) in knees, ankles, elbows, wrists
Erythema nodosum, pyoderma gangrenosum, aphthous ulceration in mouth
Sclerosing cholangitis, cholangiocarcinoma

Signs
Those of extra-intestinal manifestations
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INVESTIGATIONS

Diagnosis is made from combo of clinical, endoscopic, radiological, histopath and serological criteria.

MCS
Rule out C diff, CMV, cryptosporidium, giardia.

Radiology

AXR may show non-specific dilation; thickening
CT often performed to evaluate SB (or enterography / capsule endoscopy)

Endoscopy
Colonoscopy including ileal intubation and biopsies is essential.

Serology
p-ANCA (perinuclear antineutrophil cytoplasmic antibodies) are associated but not highly sensitive.

Indeterminant colitis
10% of patients do not get a definitive diagnosis.


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MANAGEMENT

Principles
1. Emergent colectomy should be avoided
- higher morbidity, imperfect long term outcomes.
Majority of patients will respond to modern medical therapy.
- agents like infliximab have reduced incidence of toxic colitis.
25-30% eventually require surgery, typically for:
- intractable disease
- malignancy
- fulminate colitis
- intolerance to medical management.

Non-operative

Mild attacks
Rectal steroids in a foam or liquid enema, or oral sulphasalazine
(5-ASA with a sulphur and salicylic acid component)
Moderate attacks
Oral steroids or IV hydrocortisone
Severe attacks
(>6 bowel motions/day, temp >37.5, albumin <30g/l)
Risk of toxic megacolon, perforation
Oral or IV cyclosporin. Remission maintained on sulphasalazine, azothiaprine

Operative

Indications for Surgery
Emergency
Toxic megacolon
Uncontrolled haemorrhage
Perforation
Urgent
Fulminant colitis
Anaemia
Elective
Intractable disease
Dysplasia / cancer
Side effects of medications
Relative indications
Associated diseases
- derm and ocular manifestations often improve with colectomy
- others, eg PSCholangitis and ank spond appear to act independently and do not.

Fulminant colitis
8 bloody BMs / day
SIRS - tachycardia, fever
Anaemia
AND failing to respond to IV steroids within 48-72h +/- trial of infliximab.
Can progress to toxic megacolon
- often severe SIRS / systemic upset, hypoalbuminaemia with dilated colon.

Acute Surgery
Open total abdominal colectomy with end ileostomy.
Avoid lap approach - friable colon and high risk of perf.
Rectal stump:
- stabled transection at rectosigmoid jx, or preserve and exteriorize mucus fistula; open or closed
- mucus fistula perhaps preferable as is safe, reduced abscesses, facilitates future pelvic dissection.
- either way preserve superior rectal vessels
- and place a rectal tube
Often several months or more before ready for proctectomy with or without restorative procedure.

Elective Surgery
Principles are to remove disease tissue, preserve intestinal continuity if possible
Options:
-
decision depends on disease, functional status, age and patient preference

1. Total Proctocolectomy and End ileostomy

Curative, but permanent stoma.
Perineal proctectomy facilitates layered perineal closure, lowers risk of perineal wound problems.

2. Total Abdominal colectomy and ileorectal anastomosis
Suitable if minimal rectal disease, able to have frequent surveillance
- increased risk of cancer in the rectal stump (10% at 20y)
- 10% risk of proctitis requiring proctectomy
- 10% risk of fecal incontinence
Abdominal colon removed, ileorectal anastomosis at level of sacral promontory.
End to side may be preferable to mitigate against bowel size difference at join
Low risk of leak or sexual / bladder problems.
Fibre and anti-diarrhea agents mitigate multiple daily bowel operations.

3. Continent Ileostomy
Ileum used to create a nipple valve and pouch reservoir.
Valve formed by intussusception of efferent limb.
Patients relieve by inserting a catheter.
Uncommonly used as high revision rates and increasing use of something better:

4. Restorative Proctocolectomy
Operation of choice in elective UC.
Also called ileal pouch anastomosis (IPAA)
Not suitable if acute disease, high risk ,low rectal cancer or Crohn's
Usually a two stage: IPAA with covering ileostomy then reversal.
Acute patients can have a three stage - total colectomy with end ileostomy, proctectomy with IPAA and diverting loop, then reversal.
See procedure for more details.

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