Editing Ischaemic colitis


Develops when blood supply to colon is insufficient to meet cellular demands

* Most common type of     intestinal ischaemia
* Wide spectrum of disease
* Up to 20% will require     surgery

== '''Epidemiology''' ==

* Most common form of GIT     ischaemia

== '''Risk factors''' ==

* Low-flow state
** Shock
** CCF
* Atherosclerosis
* GIT
** Constipation
** Diarrhoea
** IBS
* Surgery/procedures
** Abdominal surgery
** Aortic surgery - especially      if IMA sacrificed
** Endovascular abdominal      manipulations
** Post-colonoscopy
* Cardiovascular/pulmonary
** COPD
** AF
** HTN
* Metabolic/rheumatoid
** DM
** Dyslipidaemia
** SLE
** RA
* Miscellaneous
** Hypercoagulable states
** Sickle cell disease
** Long-distance running
* Drugs
** Anything inducing      constipation (reduced blood flow and increased intraluminal pressure)
** Cocaine and methamphetamines
** Immunomodulators
** Chemotherapy
** COCP
** Serotoninergic


== '''Pathophysiology''' ==

* Disease location
** Tends to be segmental,      mostly splenic area, but rectosigmoid and caecum can be involved
** Can be isolated right-sided      in 25%
*** Worse prognosis, more       likely to need surgery
*** More associated with IHD,       CKD, AF
** Pan-colonic IC has bad      prognosis
* Schein says to differentiate     between those comorbid (IHD, smoking, CKD) patients who get 'spontaneous'     ischaemic colitis, and those who get it secondary to systemic     hypoperfusion from another cause. However, isn't this the same end result,     and wouldn't the former predispose to the latter, and wouldn't they be     treated the same? So not a clinically significant difference.

== '''Presentation''' ==

* Variable and non-specific
* Sudden, cramping lower abdo     pain; followed by tenesmus; haematochezia (minor)
** Present in 50% of patients
* Can present with     full-thickness ischaemia - high fever, leucocytosis, acidosis, peritonitis

== '''Workup''' ==

* Stool spec - specifically     exclude CDI
* AXR
** Thumb print - submucosal      oedema - most common finding - but non-specific
** Colonic dilatation
** Mural thickening
* CT
** IV/PO contrast
** Should probably do      multi-phase scan to exclude acute mesenteric ischaemia if indicated
* Flexi sig is gold standard
** No increased risk of      perforation, but refrain from over-insufflation, and no need to go      further than the pathology
** Can't usually distinguish      between partial and full thickness ischaemia
** Ulceration/ischaemic changes
** Single stripe sign is      believed to be specific
** Mild: mucosal oedema,      erythema, petechial haemorrhage, mucosal ulceration, firm mucosa on      biopsy
** Severe: dusky mucosa,      submucosal haemorrhage, haemorrhagic ulcerations that can progress to      frank necrosis
** Abrupt cut-off to normal      mucosa is typical

== '''Management''' ==

** Although I think many in      Australia would disagree about the need for endoscopy if reassuring      presentation
* Medical
** Bowel rest
** IVF resuscitation
** Antibiotics (to cover for      translocation)
** Optimise underlying causes
* If no improvement within a     few days, repeat the imaging or perform flexi sig
* Surgery
** Absolute indications
*** Peritonitis
*** Pneumoperitoneum
*** Massive haemorrhage
*** Signs of transmural       necrosis
*** Failing medical treatment
** Operation
*** Laparotomy
*** Exploration of entire small       and large bowel
*** Segmental resection       (anatomically) with either an end ileostomy or end colostomy
*** Can staple ends and do       second-look laparotomy
** Elective surgery
*** Consider it for recurrent       episodes of colitis and pain, or stricture

== Prognosis ==

* 10% will have recurrence
* Symptoms can persist up to 3     months

[[Category:Colorectal]]