Ulcerative
colitis
Aetiology
The cause of ulcerative colitis is unknown; its prevalence among
first-degree relatives of patients is 15 times that of the general population
but there is no clear Mendelian pattern of inheritance. In spite of intensive
bacteriological studies, no organisms or group of organisms can be incriminated.
Relapse of colitis has, however, been reported in association with bacterial
dysenteries. Some cases are allergic to milk protein. Smoking seems to have a
protective effect and there have been anecdotal reports of remission of the
disease with smoking or the use of nicotine chewing gum. Patients often comment
that relapses are associated with periods of stress at home or at work, but
personality and psychiatric profiles are the same as the normal population.
There
remain three main hypotheses, none of which has been proved:
1. a mucosal immunological reaction;
2. a weakened mucous barrier;
3. defective mucosal metabolism of butyrates.
Epidemiology
There are 10—15 new cases per 100 000 population a year in the UK. The
disease has been rare in Eastern populations hut is now being reported more
commonly, suggesting an environmental cause that has developed as a result of
an increasing ‘westernisation’ of diet and/or social habits and better
diagnostic facilities. The sex ratio is equal; it is uncommon before the age of
10 and most patients are between the ages of 20 and 40 at diagnosis.
Pathology
In 95 per cent of cases the disease starts in the rectum and
spreads proximally. When the ileocaecal valve is incompetent, retrograde
(backwash) ileitis involving the last 30 cm of the ileum is likely to occur. It
is a nonspecific inflammatory disease, primarily affecting the mucosa and
superficial submucosa, and only in severe disease are the deeper layers of the
intestinal wall affected. There are multiple minute ulcers, and microscopic
evidence proves that the ulceration is almost always more severe and extensive
than the gross appearance indicates. When the disease is chronic, inflammatory
polyps (pseudopolyps) occur in up to 20 per cent of cases and may be numerous.
They result from previous episodes of ulceration heaving islands of spared
mucosa which will remain prominent when the adjacent mucosa heals. In severe
fulminant colitis a section of the colon, usually the transverse colon, may
become acutely dilated and the intestinal wall then becomes extremely thin and
may perforate (‘toxic megacolon’). On microscopic investigation there is an
increase of inflammatory cells in the lamina propia, the walls of crypts are
infiltrated by inflammatory cells and there are crypt abscesses. There is
depletion of goblet cell mucin. The crypts are reduced in number and appear to
be atrophic and irregularly spaced. With time these changes become severe and
precancerous changes can develop (r~ severe dysplasia or carcinoma in situ).
Symptoms
The first symptom is watery or bloody diarrhoea; there may be a rectal discharge of mucus which is either blood stained or purulent. Pain as an early symptom is unusual. In most cases the disease is chronic and characterised by relapses and remissions. In general, a bad prognosis is indicated by (1) a severe initial attack, (2) disease involving the whole colon and (3) increasing age, especially after 60 years. If the disease remains confined to the left colon the outlook is better.
Proctitis
Inflammation confined to the rectum accounts for about 25 per cent of
all cases. As most of the colon is healthy the stool is formed or semi-formed
and the patient is often severely troubled by tenesmus and urgency. The risk of
cancer in these cases is low. In 5—10 per cent there is spread to involve the
rest of the colon.
Left-sided
and total colitis (Fig. 57.20)
Diarrhoea usually implies that there is active disease proximal to the
rectum. Approximately 15 per cent of patients have left-sided colitis, and 25
per cent have total colitis extending beyond the midtransverse colon. The
clinical pattern is one of recurrent severe attacks of bloody diarrhoea up to 20
times a day, dehydration and fluid electrolyte losses. Anaemia and
hypoproteinaemia are common.
Disease
severity
Disease severity can be graded as:
1.mild
— rectal bleeding or diarrhoea with four or fewer motions per day and the
absence of systemic signs of disease;
2. moderate — more than four motions per day but no systemic signs of
illness;
3. severe — more than four motions a day together with one or more
signs of systemic illness: fever over 37.50C, tachycardia more than
90/minute, hypoalbuminaemia less than 30 g/litre, weight loss more than 3 kg.
Complications
of severe disease
Fulminating colitis and toxic dilatation (megacolon) (Fig. 57.21).
Patients
Perforation. Colonic perforation in ulcerative colitis is a grave
Severe
haemorrhage. Severe rectal bleeding is uncommon and may occasionally require
transfusion and rarely surgery.
Investigations
A plain abdominal film can often show the severity of disease. Faeces
are only present in parts of the colon that are normal or only mildly inflamed.
Mucosal islands can sometimes be seen and have been mentioned. Small bowel loops
in the right lower quadrant may be a sign of severe disease.
Barium
enema
The principal signs are (Fig. 57.23):
• loss of haustration, especially in the distal colon;
• mucosal changes caused by granularity;
• pseudopolyps;
• in chronic cases, a narrow contracted colon.
In
some centres an instant enema is used with a water-soluble medium for contrast
instead of barium and no bowel preparation to avoid aggravating any underlying
colitis (Fig.
Sigmoidoscopy
Sigmoidoscopy is essential for diagnosis of early cases and mild disease not showing up on a barium enema. The initial findings are those of proctitis, the mucosa is hyperaemic, bleeds on touch and there may be a pus-like exudate. Later tiny ulcers may be seen and appear to coalesce. This is different from the picture of amoebic dysentery where there are large deep ulcers with intervening normal mucosa.
Colonoscopy
and biopsy
This has an important place in management:
1. to establish the extent of inflammation;
2. to distinguish between ulcerative colitis and Crohn’s colitis;
3. to monitor response to treatment;
4. to assess long-standing cases for malignant change.
Although
it may occasionally be helpful, colonoscopy is not usually used in acute cases
for fear of aggravating the disease or perforation.
The
cancer risk in colitis
Although this is an important complication the overall risk is only
about 3.5 per cent. It is much less in early cases but increases with duration
of disease. Thus, after 20 years of colitis the risk may be as much as 12 per
cent. Carcinoma is more likely to occur where the whole colon is involved and
where the disease started in early life (Fig. 57.25). Carcinomatous change,
often atypical and high grade, may occur at many sites at once. The colon is
involved rather than the rectum and the maximal incidence is during the fourth
decade.
The
golden rule is that, when the disease has been present for 10 years or more,
regular colonoscopic checks must be carried out, even if the disease is
clinically quiescent. If on biopsy there is severe epithelial dysplasia, surgery
is indicated. Annual colonoscopy and biopsy is then part of cancer surveillance.
In the rare cases with a fibrous stricture these should be examined especially
carefully for the presence of an underlying carcinoma.
Extraintestinal
manifestations
Arthritis occurs in around 15 per cent of patients and is of the large
joint polyarthropathy type, affecting knees, ankles, elbows and wrists.
Sacroileitis and ankylosing spondylitis are 20 times more common in patients
with ulcerative colitis.
Skin
lesions: erythema nodosum, pyoderma gangrenosum or aphthous ulceration.
Eye
problems: iritis.
Liver
disease: sclerosing cholangitis has been reported in up to 70 per cent of cases.
Diagnosis is by ERCP which demonstrates the characteristic alternating
stricturing and bleeding of the intrahepatic and extrahepatic ducts.
Bile
duct cancer is a rare complication and colectomy does not appear to reduce the
risk of subsequent bile duct cancer or sclerosing cholangitis.
Treatment
Medical
treatment of an acute attack
Corticosteroids are the most useful drugs and can be given either
locally for inflammation of the rectum or systemically when the disease is more
extensive. Sulphasalazine and other 5-aminosalicylic acid (5-ASA) derivates, for
example, mesalazine and olsalazine, can be given both topically and
systemically.
Their main function is in maintaining remission rather than treating an
acute attack. Nonspecific antidiarrhoeal agents have no place in the routine
management of ulcerative colitis.
Mild
attacks
Patients with a mild attack and limited disease will usually respond to
rectally administered steroids. In those with more extensive disease, oral
prednisolone 20—40 mg/day is given over a 3—4-week period. Sulphasalazine 1
g three times a day or one of the newer 5-ASA compounds should be given
concurrently.
Moderate
attacks
These patients should be treated with oral prednisolone 40 mg/day, twice
daily steroid enemas and 5-ASA. Failure to achieve remission as an out-patient
is an indication for admission.
Severe
attacks
These patients must be regarded as medical emergencies and require
immediate admission to hospital. Their appearance is often misleading, and they
must be examined at least twice a day with particular reference to the presence
of signs of peritonism. Their abdominal girth is measured and liver dullness
should be percussed regularly. A plain abdominal radiograph is taken daily and
inspected for dilatation of the transverse colon of more than 5.5 cm. The
presence of mucosal islands on plain radiographs (see Fig.
57.22), increasing
colonic diameter or a sudden increase in pulse and temperature may indicate a
colonic perforation. A stool chart helps in the assessment of response to
therapy, and careful medical/surgical joint management is essential. Fluid and
electrolyte balance is maintained, anaemia is corrected and adequate nutrition
provided, sometimes in severe cases with intravenous nutrition. The patient is
maintained nil by mouth and treated with intravenous hydrocortisone 100—200 mg
four times daily. This can be supplemented with a rectal infusion of
prednisolone. There is no evidence that antibiotics modify the course of a
severe attack. Some patients are treated with azathioprine or cyclosporin A to
induce remission, If there is failure to gain an improvement within 5—7 days
then surgery must be seriously considered. Prolonged high-dose intravenous
steroid therapy is fraught with danger. Patients who have had weeks of
treatment, during which the colonic wall has become friable and disintegrates at
laparotomy, are now fortunately rare.
Indications
for surgery
The risk of colectomy is 20 per cent overall, ranging from 5 per
cent in those patients with proctitis to 50 per cent in those patients with a
very severe attack:
• severe or fulminating disease failing to respond to medical
therapy;
• chronic disease with anaemia, frequent stools, urgency and
tenesmus;
• steroid-dependent disease: here the disease is not severe but
remission cannot be maintained without substantial doses of steroids;
• the risk of neoplastic change: patients who on review
colonoscopy have severe dysplasia;
• extraintestinal manifestations;
• rarely, severe haemorrhage or stenosis causing obstruction.
Operations
I. In the emergency situation the ‘first-aid procedure’ is a total
abdominal colectomy and ileostomy. The rectum can either he brought out at the
lower end of the wound as a mucous fistula or closed just beneath the skin. This
has the advantage that the patient recovers quickly, the histology of the
resected colon can he checked, and restorative surgery can be contemplated at a
later date when the patient is no longer on steroids and in optimal nutritional
condition. The alternative, division of the rectum below the sacral promontory,
can result in breakdown and pelvic abscess, and makes subsequent identification
of the stump more difficult.
2. Proctocolectomy and ileostomy:
this is the procedure associated with the least compilcation rate. The patient
is left with a permanent ileostomy There is, however, a 20 per cent long-term
risk of adhesion obstruction, and 5—10 per cent of the perineal wounds are
very slow to heal. The late result will be a chronic perineal sinus which may
require repeated currettage or excision. The obvious disadvantage is an
ileostomy and although many patients cope remarkably well there is a
psychological and social ‘cost’.
Rectal and anal dissection.
Refinements of the procedure have included a close rectal dissection to minimise
damage to the nervi erigentis and hence erectile dysfunction which may occur in
0.5—2 per cent, and inter sphincteric excision of the anus which results in a
smaller perineal wound and fewer healing problems.
3. Restorative proctocolectomy with
an ileoanal pouch (Parks). In this operation a pouch or reservoir is made out of
ileum (Fig. 57.26) as a substitute for the rectum and sewn or stapled to the
anal canal. Various pouch designs have been described, hut the J is the most
popular and the most easily made using staplers (Fig.
57.27). There is some
controversy over the correct technique for ileoanal anastomosis. In the earliest
operations, the mucosa from the dentate line up to midrectum was stripped off
the underlying muscle, but it is now known that a long muscle cuff is not
needed. A mucosectomv of the upper anal canal with an anastomosis at the dentate
line is claimed to remove all of the at risk mucosa and any problem of
subsequent cancer. It may also result in imperfect continence with nocturnal
seepage. The alternative is a double stapled anastomosis to the top of the anal
canal preserving the upper anal canal mucosa. Continence appears to be better,
but the theoretical risk of leaving inflamed mucosa remains.
The procedure can he carried
out in one, two or three stages. In selected cases a covering loop ileostomy is
omitted hut is usually used. Complications include pelvic sepsis — usually
resulting from a leak of the ileoanal anastomosis, small bowel obstruction and
pouch vaginal fistula. Frequency of evacuation is determined by pouch volume,
completeness of emptying, reservoir inflammation and intrinsic small bowel
motility, but can be between three and six evacuations daily. Although
associated with a higher complication rate, it is rapidly becoming the operation
of choice in younger patients, avoiding a permanent ileostomy. About 20 per
cent of patients have an episode of pouchitis, that is, inflammation of the
reservoir, at some time. It usually responds to treatment with metronidazole.
4. Colectomy and ileorectal
anastomosis: if there is minimal rectal inflammation this can occasionally he
used; it has largely been superseded by restorative proctocolectomy.
5.
ileostomy with a continent
intra-abdominal pouch (Kock’s procedure). A reservoir is made of ileum and
just beyond this a spout is made by inverting the efferent ileum into itself to
give a continent valve just below skin level. The pouch is emptied by the
patient inserting a catheter through the valve; now rarely used.
Ileostomy
End ileostomy (Brooke). In those patients with a permanent ileostomy
there must be scrupulous attention to detail during the operation to ensure that
the patient has a good functional result. The position of the ileostomy should
be carefully chosen by the patient with the help of a stoma care nursing
specialist. The ileum is normally brought through the lateral edge of the rectus
abdominis muscle. The use of a spout (Fig. 57.28) was originally described by
Bryan Brooke and it should project some 4 cm from the skin surface. A disposable
appliance is placed over the ileostomy so that it is a snug fit at skin level.
ileostomy
care
During the first few postoperative days, fluid and electrolyte balance
must he adjusted with great care. There may he an ‘ileostomy flux’ while the
ileum adapts to the loss of the colon, and the fluid losses can amount to 4 or 5
litres/day. The stools thicken in a few weeks and are semisolid in a few
months. The help, skill and advice of the stoma care nursing specialist are
essential. Modern appliances have transformed stoma care and skin problems are
unusual (Fig. 57.29).
Complications
of an ileostomy include prolapse, retraction, stenosis, bleeding and
paraileostomy hernia.Loop ileostomy. This
is often used to defunction a pouch ileoanal procedure or even a low anterior
resection. A knuckle of ileum is pulled out through a skin trephine in the
right iliac fossa. An incision is made in the distal part of the knuckle and
this is then pulled over the top of the more proximal part to create a spout on
the proximal side of the loop with a flush distal side still in continuity. This
allows near-perfect defunction, but also the possibility of restoration of
continuity by taking down the spout and reanastomosing the partially divided
ileum.