Ischaemic Bowel Disease

Ischaemic Bowel Disease

·        Distribution:

o  Vascular occlusion: superior mesenteric

o  Watershed lesions (eg splenic flexure, rectum)

·        Transmural infarction: 

o  Pathogenesis: arterial thrombosis, embolic occlusion, venous thrombosis or strangulation and torsion

o  Macroscopic appearance: Red and intensely congested.  Subsequently gangrenous

o  Microscopic appearance: transmural necrosis, congested with blood, epithelium sloughed off, inflammation, perforation in 3 – 4 days

o  Clinical: severe pain, nausea, collapse, 50 – 75% die

·        Mucosal Infarction:

o  Pathogenesis: non-occlusive hypoperfusion damaging only the inner layers due to shock, cardiac failure, etc

·        Macroscopic appearance: congested in patches or large areas. Mucosa haemorrhagic, oedematous, ulcerated

·        Microscopic appearance: Necrosis of mucosa, remainder OK

·        Clinical: pain, bloody diarrhoea, shock, potentially reversible