Vascular Surgery

Question 1

Order of tests in vascular surgery

Answer 1

non-invasive Bedside tests
Ultrasound
MR-Angiography
CT-A (can cause contrast induced nephropathy + radiation exposure)
Direct Angiography

Increased complexity will determine when these investigations are ordered -> increased risk = more willing to pursue some of these

Question 2

Contraindication into CT-Angiogram

Answer 2

End Stage renal disease

Question 3

Name some bedside tests

Answer 3

Berger’s test - angle to which the leg has to be raised before it becomes pale, whilst lying down. In a limb with a normal circulation the toes and sole of the foot, stay pink, even when the limb is raised by 90 degrees.

Dopplers:

ABPI

TOE Pressures

Question 4

Name 3 types of waveforms in dopplers

Answer 4

Triphasic: normal, 3 components

Biphasic (moderate stenosis): slightly damped, upstroke less brisk, loss of reversal in diastole

Monophasic (severe stenosis): low amplitudes and slow, blunted antegrade systolic flow, which continues into diastole. Monophasic arterial waveforms are always abnormal and are often seen downstream from stenoses or in collateral vessels formed around the occlusive disease

Question 5

what is ABPI

Answer 5

non-invasive method of assessing peripheral arterial perfusion in the lower limbs

Question 5

Formula for ABPI

Answer 5

Left ABPI = (highest pressure of either left PTA or DP) ÷ (highest brachial pressure)

Right ABPI = (highest pressure of either right PTA or DP) ÷ (highest brachial pressure)

Question 6

Why is toe pressure used

Answer 6

In diabetes, there is concentric calcifications in wall -> cannot be compressed > ABPU not trusted much

In atherosclerosis, the plaque is usually just on one side and one side can be compressed, allowing the aBPI to have better application

Question 6

Value for ischaemic ABPI

Answer 6

<0.3

Question 6

What are the different modes of Ultrasound

Answer 6

FIRSTLINE
B-Mode, bright mode. shades of grey with no indication of flow

B-Mode with Doppler: allows for feel of direction, adds color (away from machine = blue; to machine =red)

No radiation, easy to administer, can identify blockages

Question 7

What is duplex

Answer 7

ULtrasound in B-Mode + Doppler = duplex

Question 8

can velocity be calculated from duplex

Answer 8

yes - can compare velocity at different points in vessel to identify stenosis.