colitis_ischaemic
ischaemic colitis
introduction
epidemiology
90% occur in >60 yr olds
younger pts tend to have either:
chronic ischaemia may be due to Sx, esp. AAA repair (0.1-10% of AAA repairs)
most cases due to arteriole shunting, spasm or poor perfusion of mucosal vessels
some cases are caused by embolus or thrombus of mesenteric artery
most cases involve the splenic flexure with sparing of rectum as this is less dependent on inf. mesenteric A
pathology
there are three types:
transient, reversible ⇒ mucosal sloughing and then regeneration (most common type)
stricturing - haemorrhagic infarction of mucosa ⇒ ulceration, healing by fibrosis
gangrenous - complete bowel wall infarction ⇒ perforation, peritonitis and death
clinical presentation
AXR and CT findings of ischaemic colitis
most plain films are normal or show a non-specific ileus pattern!
thickening of the colonic wall, with luminal narrowing and transverse ridging
“thumbprinting” of the bowel wall due to oedema
fixed, rigid, tubular, ahaustral bowel loops
pneumatosis (gas in bowel wall):
benign causes of pneumatosis include collagen vascular diseases, steroids, COPD and idiopathic causes.
this can be seen in any severe bowel insult resulting in bowel wall necrosis and is a classic feature of necrotizing enterocolitis of the newborn infant.
free gas in peritoneal cavity (uncommon) or in mesenteric veins and portal vein (these findings are ominous and indicate infarction)
colitis_ischaemic.txt · Last modified: 2018/08/11 01:29 (external edit)