Angiodysplasia

Question 1

What is the most common vascular abnormality of the GI tract?

Answer 1

Angiodysplasia

Responsible for approx 6% of lower GI bleeds and 8% of upper GI bleeds.

Question 2

What causes angiodysplasia?

Answer 2

Formation of arterivenous malformations between previously healthy blood vessels

Question 3

Where does angiodysplasia most commonly occur?

Answer 3

In the caecum and ascending colon

Question 4

Epidemiology

Answer 4

1-2% prevalence

Second most common cause of rectal bleed in those >60y

Most common cause for bleeding from small bowel

Question 5

Pathophysilogy of acquired angiodysplasia

Answer 5

Reduced submucosal venous drainage in the colon due to chronic and intermittent contraction of the colon.

This gives rise to dilated and turtuous veins.

This further causes loss of pre-capillary sphincter competency and in turn causes the formation of small arteriovenous communications.

This is characterised by a small tuft of dilated vessels.

Question 6

Pathophysiology of congenital angiodysplasia.

Answer 6

Hereditary haemorrhagic telangiectasia

Rendu-Osler-Weber syndrome

Heyde’s syndrome

Question 7

What is Heyde’s syndrome

Answer 7

Aortic stenosis + angiodysplasia

Leads to GI bleed

Question 8

Clinical features

Answer 8

Rectal bleeding and anaemia

Can be asymptomatic and only diagnosed incidentally on colonscopy (10%)

Painless occult PR bleed (most common presentation)

Acute haemorrhage (10-15% of cases)

Question 9

What does the clinical presentation depend on?

Answer 9

On the location and severity of the arteriovenous malformation.

Upper GI lesions can cause haematemesis or melaena

Lower GI lesions (more common) are more likely to present as haematochezia

Question 10

Dx

Answer 10

Oesophageal varices

GI malignancies

Diverticular disease

Coagulopathies

Question 11

Examination findings

Answer 11

Usually minimal or completely normal

In Heyde’s syndrome there might be aortic stenosis

Question 12

Laboratory investigations

Answer 12

Blood tests with FBC, U&Es, LFTs and clotting + haematinics

G&S or crossmatch might be warranted if there is a need for transfusion.

Question 13

Imaging of angiodysplasia.

Answer 13

OGD to exclude malignancy

Colonoscopy if more leading towards a distal AV lesion.

Question 14

Small bowel AV lesions might be hard to identify.

How is this done?

Answer 14

By wireless capsule endoscopy

Question 15

If there is an overt angiodysplastic bleed, what investigation might be done?

Answer 15

Mesenteric angiography to confirm the location of a lesion

This is in order to plan for intervention as necessary.

Question 16

What can angiography involve?

Answer 16

Radionuclide scanning

CT scanning

MRI scanning

This is to image the GI tract vascular supply after injection of a radio-opaque contrast into the vessels

Question 17

How can patients admitted with angiodysplasia be treated?

Answer 17

Conservatively especially if there is only minimal limited bleeding in a haemodynamically stabe patient.

Bed-rest and IV fluid support along with potential tranexamic acid.

10% of patients with angiodysplasia will present with a major GI bleed and need to be managed according to that protocol.

Question 18

Indications for definitive therapy.

Answer 18

Persistent or severe cases when bleeding sites are identified.

Question 19

Two main methods of definitive treatment

Answer 19

Endoscopy therapies

Radiographic therapies (mesenteric angiography)

Question 20

What is usually the first line of management?

Answer 20

Endoscopy therapy with argon plasma coagulation

Question 21

Explain argon plasma coagulation

Answer 21

Electrical current and argon are subjected to the bleeding vessel.

This is a safe, cost-effective and usually successful treatment option.

Question 22

Give exampes of other endoscopic techniques

Answer 22

Monopolar electrocautery

Laser photoablation

Sclerotherapy

Band ligation

Question 23

When is mesenteric angiography done?

Answer 23

Used for small bowel lesions that cannot be treated endoscopically.

Question 24

Explain mesenteric angiography

Answer 24

Involves super-selective catheterisation and embolisation of the vessel that has been demonstrated to the bleeding.

This is by extravasation of contrast dye into the bowel lumen from the identified angiodysplastic lesion.

Question 25

When else might mesenteric angiography be indicated?

Answer 25

GI bleed from any other location where endoscopic therapy failed

When endoscopy is not a suitable option like people who are unfit for it.

Question 26

Explain surgical intervention.

Answer 26

Where resection and anastomosis of the affected segment of bowel is required to limit bleeding

Bowel resection in patients with angiodysplasia is associated with a relatively high mortality.

Question 27

Indications of surgical management

Answer 27

Continuation of severe bleeding despite angiographic and endoscopic management

Severe acute life-threatening GI bleed

Multiple angiodysplastic lesions that cannot be treated medically

Question 28

Complications of angiodysplasia

Answer 28

Mainly related to treatment

Re-bleeding post-therapy is quite common

Endoscopic techniques have a small risk of bowel perforatio

Mesenteric angiography carries risks of haematoma formation, arterial dissection, thrombosis and bowel ischaemia.