4: Mesenteric Ischaemia

Question 1

define acute mesenteric ischaemia

Answer 1

sudden decrease in blood supply to the bowel –> bowel ischaemia and necrosis

Question 2

what are the 4 types of acute mesenteric ischaemia

Answer 2

• Thrombus-in-situ (Acute Mesenteric Arterial Thrombosis, AMAT)
• Embolism (Acute Mesenteric Arterial Embolism, AMAE)
• Non-occlusive cause (Non-Occlusive Mesenteric Ischemia, NOMI)
• Venous occlusion and congestion (Mesenteric Venous Thrombosis, MVT)

Question 3

how does mesenteric ischaemia present

Answer 3

• generalised abdo pain
• out of proportion to clinical findings
• ± N&V
• O/E: non specific tenderness
• features of globalised peritonism

Question 4

what labs tests are performed for acute mesenteric ischaemia

Answer 4

• ABG: assess degree of acidosis + serum lactate to show severity of bowel infarction
• routine bloods
• G&S

Question 5

in what conditions can amylase be raised

Answer 5

• mesenteric ischaemia
• ectopic pregnancy
• bowel perf
• DKA

Question 6

how is mesenteric ischaemia definitively diagnosed

Answer 6

CT + IV contrast (in arterial and portal venous phase)

Question 7

how will arterial bowel ischaemia present on CT imaging

Answer 7

• oedematous bowel secondary to ischaemia and vasodilation
• progressing to loss of bowel enhancement
• pneumatosis
• should also highlight an acute occlusion of typically SMA or coeliac artery w halo sign around occlusion

Question 8

what is involved in the initial management of acute mesenteric ischaemia

Answer 8

• urgent IV fluids
• catheter
• fluid balance chart
• confirmed cases = broad spec abx due to risk of faecal contamination if perf and bacterial translocation

Question 9

what is a patient at high risk of developing in acute mesenteric ischaemia

Answer 9

significant acidosis –> multi-organ failure

Question 10

what surgical options are available for mesenteric ischaemia

Answer 10

• excision of necrotic or non-viable bowel, if not suitable for revascularisation
• revascularisation of the bowel: involving removal of any thrombus or embolism via radiological intervention (suction thrombectomy or thrombolysis)
• venous ischaemia requires anticoag and bowel resection

Question 11

what are the main complications of mesenteric ischaemia

Answer 11

bowel necrosis and perforation

Question 12

what is chronic mesenteric ischaemia

Answer 12

reduced blood supply to the bowel which gradually deteriorates over time as a result of atherosclerosis in the coeliac trunk, SMA or IMA

Question 13

who is chronic mesenteric ischaemia more common in

Answer 13

• > 60 yrs
• more common in female pt

Question 14

why are pt with chronic mesenteric ischaemia generally asymptomatic

Answer 14

due to collateralisation
- means that commonly at least 2 out of coeliac, SMA,IMA must be affected for pt to be symptomatic

Question 15

what is the classical set of symptoms associated w chronic mesenteric ischaemia

Answer 15

• Postprandial pain – classically occurring around 10mins-4hrs after eating
• Weight loss – a combination of decreased calorie intake and malabsorption
• Concurrent vascular co-morbidities, e.g. previous MI, stroke, or PVD

Question 16

what are examination findings of chronic mesenteric ischaemia

Answer 16

often non-specific
- evidence of malnutrition/cachexia
- generalised abdo tenderness
- abdo bruits

Question 17

what are appropriate investigations into chronic mesenteric ischaemia

Answer 17

• bloods: will appear normal, check electrolytes e.g. Mg, Ca for malnutrition
• anaemia: lipids profile or blood glucose level
• CTA: diagnostic test of choice

Question 18

describe mesenteric angioplasty

Answer 18

• performed percutaenously through femoral or brachial/axillary artery to allow catheter to pass through
• once in region, small balloon expanded to dilate vessel and stented

Question 19

what are the main complications of chronic mesenteric ischaemia

Answer 19

bowel infarction
malabsorption