Non-Invasive Vascular Procedures
ABI is a non-invasive diagnostic study to evaluate perfusion of the lower limbs. It is usually performed with a further assessment of the lower digit wave forms and pressures.
A normal ABI and digit pressures indicates that arterial disease is unlikely.
This test is performed if a patient has leg pain on exercise but the ABI is normal at rest. A normal ABI post exercise is an excellent indicator that lower limb arterial disease is not present.
Lower Limb Arterial Duplex
If a reduced ABI is obtained a lower limb arterial duplex scan may be carried out. This diagnostic study images the areas of narrowing or blockage in the arterial tree.
Pre-operative Duplex Marking
Before a vascular or endovascular procedure is carried out on the lower limb any blockages or narrowings are marked on the skin.
Post-operative Graft Surveillance
Once a vascular graft or bypass is put in place it is checked at regular intervals to see if it is free of narrowing or blockage. This aids early intervention in the case of a problem and results in good long-term outcomes.
Post-operative Angioplasty Surveillance
Once a peripheral angioplasty with or without stents is carried out it is checked at regular intervals to see if it is free of narrowing or blockage. This aids early intervention and results in good long-term outcomes.
Carotid Artery Duplex
This test images the extra-cranial portion of the carotid arteries. These arteries supply a large portion of the brain with blood. A narrowing or blockage of these arteries can cause stroke. A negative carotid duplex scan indicates that the likelihood of a CVA originating from the imaged arteries is extremely small. In this department a study of the vertebral arteries (arteries which run close to the bones of the neck) is carried out routinely during a carotid artery duplex.
Abdominal Aortic Duplex
The abdominal aorta is the largest artery in the abdominal cavity. This vessel may also become narrowed or blocked but more common is a dilatation of the artery known as an abdominal aortic aneurysm (AAA.)
AAA increase in size very slowly in general over a period of years or even decades.
An endovascular repair of AAA is called an EVAR. Before the procedure the main arteries of the pelvis (the iliac and common femoral arteries) must be measured and shown to be free of significant narrowing.
Following an EVAR the graft and the aneurysm sac must be followed up at regular intervals to assess patency and to look for any leaks of the endovascular device.
Upper Limb Arterial Pressures
This is a non-invasive diagnostic study to evaluate perfusion of the upper limbs. As for the ABI, upper limb digit waveforms and pressures are usually evaluated also.
Thoracic Outlet Compression (TOC) Studies
Following a normal upper limb arterial pressure test it is sometimes necessary to carry out TOC studies. This test is to rule out mechanical obstruction of the arteries that supply the upper peripheries during movement. Thoracic outlet compression syndrome (TOCS) can affect people of all ages.
Following an abnormal upper limb arterial pressure or in incidental finding of uneven brachial pressures (>10mmHg) during another test, a carotid duplex study may be carried out with an assessment of the subclavian artery to check for any blockages here.
Upper-Limb Arterial Duplex
It may sometimes be necessary to assess the arterial circulation in the rest of the upper limb if upper limb arterial pressures and carotid-subclavian duplex have already been carried out and not given a conclusive result.
Lower Limb Deep Venous Duplex
This assessment of the deep veins is usually performed to rule out a deep vein thrombosis (DVT.) Duplex ultrasound is an excellent method of detecting and following up DVT.
Deep and Superficial Lower Limb Venous Duplex
The most common use of this test is for detection and mapping of varicose veins. The deep veins must also be assessed to ensure that no deep venous insufficiency is present.