diverticular disease Flashcards
definition of diverticular disease
A GI diverticulum is an outpouching of the gut wall (colonic mucosa and submucosa), usually at sites of entry of perforating arteries.
Diverticulosis means that diverticula are present
diverticular disease implies they are symptomatic ie associated with compliocations
Diverticulitis refers to inflammation of a diverticulum due to impaction of faecalith and pooling of gut flora.
Hinchey classification of acute diverticulitis: Ia: phlegmon, Ib and II: localized abscesses, III: perforation with purulent peritonitis or IV: faecal peritonitis.
pathophysiology of diverticular disease
Macro: Diverticulae are most common in the sigmoid and descending colon. Absent from the rectum.
Micro: consist of herniated mucosa and submucosa through the muscularis, particularly at sites of nutrient artery penetration with a peritoneal covering - associated colonic smooth muscle hypertrophy resulting in luminal stenosis
aetiology of diverticular disease
most occur in sigmoid colon with 95% complications at this site, but R sided and massive single diverticular can occur
high interluminal pressures (perhaps because of lack of fibre) force the mucosa to herniate through the mucosal layers at weak points adjacent to the penetrating vessels
30% of westerners have diverticulosis by age 60
mostly asymptomatic
low fibre, refined diet = loss of stool bulk = high colonic intraluminal pressures must be generated to propel the stool - herniation of the mucosa and submucosa through the muscularis
RF for diverticular disease
low fibre, refined diet, increasing age, connective tissue disorders
pathogenesis of diverticular disease
absent from the rectum
Proposed diverticular obstruction by inspissated faeces can lead to bacterial overgrowth, toxin production and mucosal injury and diverticulitis, perforation, pericolic phlegmon, abscess, ulceration and fistulation or stricture formation
epidemiology of diverticular disease
60% western people will have it
rare <40yrs
R sided diverticula are more common in Asia
sx of diverticular disease
- often asymptomatic 80-90%
- PR bleeding
- fever in diverticulitis
- altered bowel habit
- +- L sided colic relieved by defaecation
- nausea
- flatulence
- high fibre diets dont help symptoms
- Diverticular disease is a common cause of fistula, either with small bowel, bladder or vagina and may present with pneumaturia, or faeculent vaginal discharge, or recurrent UTI
sx of diverticulitis
all symptoms of diverticular disease plus:
pyrexia
hx of diverticular disease
often asymptomatic 80-90%
alternating constipation (pellet faeces) and diarrhoea
GI bleed - PR bleeding may be acute or chronic
diverticulitis - pyrexia and LIF or suprapubic (referred from hindgut) abdominal pain
features of complications: pneumaturia, faecaluria and recur-rent UTI may be due to a vesicocolic fistula or enterocolic fistula
can mimic malignancy
signs of diverticular disease
usually normal
occaisionally lower abdominal tenderness and faecal loading
diverticulitis
- raised WCC, CRP/ESR
- tender colon +_ localised or generalised peritonism if perforation has occured
ix for diverticular disease
common incidental finding at colonoscopuy
CT abdo is best to confirm acute diverticulitis and can identify extent of disease and any complications eg colovesical fistulae
colonoscopy risk perforation in acute setting
AXR may identify obstruction or free air (perforation)
FBC: anaemia, raised WCC and CRP in diverticulitis
check clotting and cross-match if bleeding
barium enema +- air contrast - Demonstrates the presence of diverticulae with a saw-tooth appearance of lumen, reflecting pseudohypertrophy of circular muscle (should not be performed in acute setting as there is a danger of perforation).
mx for diverticular disease
antispasmodics eg mebeverine 135mg/8hr PO
surgical resection sometimes needed
diverticulitis
- mild attacks can be treated at home with bowel rest (fluids only) +- AB
- admit for analgesia, NBM, IV fluids and IV AB (cephalosporin and metronidazole)
if abscess forms need percutaneous CT guided drainage
treat conservatively first - rehydration, NBM, broad spectrum IV AB
Follow up CT to ensure abscess resolution – if enlarging consider percutaneous drainage
Interval colonoscopy will be required once acute inflammation has resolved
if GI bleed - PR bleeding os often managed conservatively eith MBM, IV rehydration,AB and transfusion if necessary
chronic - high fibre diet and buliking agent eg methylcellulose, laxatives may be required if constipation is severe. Encourage high fluid intake
when is surgery needed for diverticulitis
necessity of surgery depends on infective complications
Stage 1 - Pericolic or mesenteric abscess - Surgery rarely needed
Stage 2 - Walled off or pelvic abscess - May resolve without surgery
Stage 3 - Generalized purulent peritonitis - Surgery required
Stage 4 - Generalized faecal peritonitis - Surgery required
indications for elective surgery include stenosis, fistulae, or recurrent bleeding
surgery may be necessary with recurrent attacks or when complications develop eg severe bleeding or infection
Sigmoid colectomy, Hartmann’s procedure, fistulectomy or drainage of pericolic abscesses are some operations performed.
complications of diverticular disease
perforation
haemorrhage
fistulae - Enterocolic, colovaginal, or colovesical (pneumaturia ± intractable UTIS). Treatment is surgical, eg colonic resection.
abscesses
post infective strictures may form in the sigmoid colon
diverticulitis
colonic obstruction
perforation
ileus, peritonitis and shock
mortality 40%
manage as for an acute abdo
At laparotomy a Hartmann’s procedure may be performed
Primary anastomosis is possible in selected patients.
Emergency laparoscopic management is an emerging alternative.
