Bowel ischaemia****

Question 1

Acute mesenteric ischaemia (AMI):

What 2 blood vessels are commonly affected causing an acute reduction in blood flow?

What are some causes?

Answer 1

Superior mesenteric artery  (SMA)
Coeliac artery (CA)

Left heart or aortic thromboembolism (e.g. post MI, AF, infective endocarditis)
Atherosclerosis - similar to angina
Vasculitis

Question 2

Chronic mesenteric ischaemia (CMI):

What 3 vessels are typically affected?

What type of bowel does it affect?

What is it also referred to?

Answer 2

Superior mesenteric artery (SMA)
Inferior mesenteric artery (IMA)
Coeliac artery (CA)

Both

Angina - also known as Intestinal angina

Question 3

Ischaemic colitis - generally commoner and milder than mesenteric ischaemia:

What type of bowel does it affect?

What 2 arteries are affected?

Typical causes?

Answer 3

Large bowel

Middle colic artery (Superior mesenteric artery territory)
Left colic artery (Inferior mesenteric artery)

Atherosclerosis
Emboli
Hypoperfusion (e.g. sepsis)
Drugs (contraceptive pill, cocaine)

Question 4

Ischaemic colitis - generally commoner and milder than mesenteric ischaemia:

Where is usually affected? What is this area referred to as?

Answer 4

Splenic flexure - known as Griffith’s area

Question 5

Acute mesenteric ischaemia (AMI):

Presentation - 3

CMI:

Presentation:

• Triad of abdo pain - severity? character? what makes it worse?
• Eating hurts so why would happen? - 2
• What may be heard on auscultation?

Answer 5

Moderate to severe pain
Sudden onset
Symptoms out of proportion to exam findings

Severe
Colicky
Post-prandial abdo pain - after eating

Weight loss and fear of eating (sitophobia)

Abdominal bruits due to atherosclerosis

Question 6

Ischaemic colitis - Presentation:

• Severity?
• Onset?
• Character?
• Site?

What may also be present in severe cases with necrosis and/or perforation?

Answer 6

Moderate
Onset over hours
Sometimes colicky
LIF - Tenderness over affected bowel area

Peritonitis with abdo distention, guarding and rebound tenderness

Question 7

Why might you get PR bleeding and diarrhoea?

Answer 7

Mucosal sloughing - necrotic surface epithelial cells are discarded from the small intestinal mucosa leading to bleeding

Question 8

Investigations:

Bloods - why do you do?

• FBC - 2
• ABG - 2
• Amylase - 1

What bedside test could show a possible cause of acute mesenteric ischaemia?

Answer 8

Raised WBC - infection and low Hb - anaemia

Metabolic acidosis and raised lactate

Raised amylase - pancreatitis

ECG - arrhythmias including AF as a cause

Question 9

Investigations:

Imaging:

• What may an abdo XR show? - 1
• What may mucosal oedema look like on AXR?
• What can be done to find pneumoperitoneum in perforation?

What could be done to look at vasculature?

Answer 9

Bowel dilation
Thumb-print sign - look at pics
Erect XR - if perforated

CT abdo with IV contrast - can see mucosal oedema, ectopic gas and vessel occlusion

Question 10

What can be done for AMI as further diagnostic tests?

Colonoscopy can be done for ischaemic colitis. What could it show?

Answer 10

Mesenteric angiography

Mucosal sloughing
Friability
Ulceration

Question 11

Management - AMI and ischaemic colitis:

What should be done immediately?

Why are IV ABs also given?

Answer 11

Supportive care

Risk of bacterial translocation - Bacterial translocation is defined as the passage of viable bacteria from the gastrointestinal (GI) tract to extraintestinal sites, such as the mesenteric lymph node complex (MLN), liver, spleen, kidney, and bloodstream.

Question 12

Management - AMI:

Papaverine is given. What is it and what does it do? How long is it given for?

In severe disease, what can be done via laparoscopy/laparotomy? - 2

What is given after surgery?

Answer 12

Opioid antispasmodic which causes vasodilation
Infusion and continued 24 hrs

Embolectomy
Arterial bypass and resection of any infarcted bowel

Heparin or thrombolysis or standalone Rx in mesenteric vein thrombosis

Question 13

Management - Ischaemic Colitis:

If its pain is severe and sudden, what is done?

What is done if it is not severe?

Answer 13

Partial or total colectomy

Usually self-resolving

Question 14

Management - CMI:

What surgery can be done?

What is done if unfit for surgery?

What else also needs to be thought about?

Answer 14

Systemic-mesenteric bypass

Percutaneous angioplasty - a procedure that can open up a blocked blood vessel using a small, flexible plastic tube, or catheter, with a “balloon” at the end of it. When the tube is in place, it inflates to open the blood vessel, or artery, so that normal blood flow is restored.

Managing CVD risk factors - smoking, alc

Question 15

Complications - 3

Answer 15

Perforation
Sepsis
Strictures