Vasculature

Question 1

A 65 year old male patient presents with sharp generalised shock and bilateral leg ischemia:

what is the most important first clinical examination?

Answer 1

A vascular examination of the abdomen for AAA;

• check for tender mass in abdomen and pulses in all limbs (AAA often has other aneurysms in the body, especially popliteal)
• be aware clinical examination is difficult in obese people, and thin people give false positives
• clinical examination only picks up on 40-50% of AAA

Question 2

What is the difference between a transmitted and a expansile pulsation when palpating a swelling in the abdomen?

Answer 2

Upon palpating a swelling:

Transmitted pulsation is via something in the abdomen that is transmitting the pulse of the aorta, it isn’t pulsing itself

• putting the patient in knee-elbow position will remove the pulsation from the swelling
• the pulse only moves anteriorly (fingers move upward)

Expansile pulsation is an artery that is swollen and therefore the swelling itself is pulsing with the beat of the heart (most likely an aneurysm)
- pulse moves anteriorly AND laterally (fingers move outward)

Question 3

What is the investigative pathway for suspected AAA?

Answer 3

1. Clinical examination - vascular examination
2. Urgent CT scan
   - confirms diagnosis
   - decides if endovascular repair is possible
3. Endovascular repair:
   - Clamp the aorta above the aneurysm in order to repair it
   - where the clamp is placed decides the stress put on the heart and the parts of the body that undergo ischemia

Question 4

What are the Fontaine classifications used for?

Answer 4

The Fontaine classifications (1-4) are the grades of chronic limb ischemia in peripheral vascular disease.

Fontaine 1 - asymptomatic, fit

Fontaine 2 - claudication (aching muscles on effort)

Fontaine 3 - rest pain (claudication at rest)

Fontaine 4 - tissue loss (vascular ulcer or gangrene)

Question 5

How do we investigate cerebrovascular disease?

Answer 5

Duplex ultrasound - to visualise areas where the stenosis is.

If degree of stenosis is uncertain, MR or CT is used afterwards to back up the duplex findings.

Question 6

What is the relevance of maximum transverse aortic diameter in the treatment of an aneurysm?

Answer 6

The maximum transverse diameter (MTD) dictates the treatment:

Rupture of the aneurysm (highest danger) is exponentially associated with MTD

Normal aorta diameter - 2.5cm
Small AAA - 4.5cm
Large AAA - 5.5cm

7% risk at 6cm
50% annual risk of rupture at 8cm

Question 7

How do we diagnose an aortic dissection?

Answer 7

TOE - transoesophageal echocardiogram

Or: CT with contrast (-better since we can see entire aorta, not just the part the probe is against)

Or: MR angiogram (- best for diagnosis)

Question 8

If abdominal aortic aneurysms are often asymptomatic until they rupture, (at which point they have a high mortality rate), how do we avoid people getting to the point of rupture?

Answer 8

The NHS has an abdominal aortic aneurysm screening programme:

All men who reach 65 are invited to AAA screening, this means a USS of the abdomen.

Results:

Normal = less than 3cm diameter
Small aneurysm = 3-4.4cm diameter - follow up scans
Medium aneurysm = 4.5-5.4cm - follow up scans
Large aneurysm = 5.5cm or more - referral to vascular surgeon

(Around 1 in 70 men aged 65-74 in England have an AAA - highest incidence therefore the targeted group)