by Hannah Farrell
Our expert witnesses in vascular surgery specialise in pathology of the veins and arteries that circulate blood to and from the tissues of the body. They are experts in performing vascular and endovascular surgery, such as carotid stenting, aortic surgery, venous stripping, venous ligation, sclerotherapy, and revascularisation of the lower limbs.
Our experts in vascular surgery have a profound knowledge of managing conditions such as critical limb ischaemia, varicose veins, claudication, thoracic outlet syndrome, venous ulcers, acute mesenteric ischaemia, and thrombophlebitis. Further, their extensive experience in the operating theatre means they can review operation notes and assess the practical nature of the surgical procedures performed.
With a strong understanding of appropriate standards of care and NICE Guidelines, in addition to a thorough knowledge of treatment pathways, our expert witnesses in vascular surgery can advise on causation, breach of duty, current condition, and prognosis in individuals with vascular conditions and who have undergone surgical vascular intervention.
See below for a brief overview on vascular surgery. Alternatively, contact an expert witness in vascular surgery to see how they can help.
What is Vascular Surgery?
Basic Anatomy & Physiology
The three main types of blood vessels in the human body are categorised as arteries, veins, and capillaries. Arteries have strong walls and carry (usually oxygenated and nutrient rich) blood under high pressure to the capillaries in the body tissues. The capillaries are very small blood vessels, with thin walls, that undertake nutrient exchange and oxygen delivery to the tissues of the body, whilst returning deoxygenated blood to the veins. The veins then carry (usually deoxygenated) blood away from the soft tissues, under low pressure. To prevent the backflow of blood in the low-pressure environment, the veins contain valves; these valves are particularly important when blood flow is against gravity, for example in the legs.
Thoracic Blood Vessels
The main artery of the body is the aorta. This is a thick-walled large artery that carries oxygenated blood away from the heart, under very high pressure. The aorta can be divided into four sections:
- Ascending aorta – branching into the aortic sinuses and left and right coronary arteries;
- Aortic arch – branching into the brachiocephalic trunk, left common carotid artery, and left subclavian artery;
- Descending (thoracic) aorta – numerous branches supplying the structures within the thoracic cavity; and
- Abdominal aorta – numerous branches supplying the structures within the abdominal cavity.
The main vein in the body is the superior vena cava (SVC). This is large, containing no valves, and transports blood from the head and upper limbs back to the heart. The inferior vena cava (IVC) and its tributaries returns blood to the heart from the abdomen and lower limbs. Before returning to the heart, nutrient rich blood from the digestive system is circulated via the portal venous system to the liver for processing.
Head & Neck Blood Vessels
The head and neck, including brain, have a very complex blood supply. The main arteries of the neck include the internal and external carotid arteries, vertebral arteries, and the subclavian arteries. The main venous drainage includes the internal, external, and anterior jugular veins and the subclavian veins.
Upper & Lower Limb Blood Vessels
The upper limb has an arterial supply comprising the subclavian, axillary, brachial, radial, and ulnar arteries. The veinous drainage includes the basilic, cephalic, median cubital, brachial, radial, and ulnar veins. The lower limb has an arterial supply comprising the femoral, circumflex, profunda femoris, popliteal, obturator, gluteal, tibial, and peroneal arteries. The foot also receives blood via the dorsalis pedis and posterior tibial arteries. The veinous drainage of the lower limbs includes the popliteal, femoral, profunda femoris, gluteal, iliac, fibular, and tibial veins, which are all located deep in the limb. More superficially lie the great saphenous and small saphenous veins; as these are more easily accessed, they are often used for vein harvesting.
Atherosclerosis
All blood vessels can undergo a pathological process known as atherosclerosis, whereby there is scarring, inflammation, and accumulation of lipids (fats) within the vessel wall, forming an atherosclerotic plaque. Should the surface of the atherosclerotic plaque become disrupted, a thrombus (blood clot) may form.
Arteries are particularly susceptible to atherosclerosis, leading to thickening of the arterial wall, narrowing of the lumen, calcification, and stenosis (hardening). This process leads to ischaemia (reduced blood flow) of the body tissues, which presents in a variety of ways, depending on which blood vessels are affected:
- Lower/upper limb arteries – critical limb ischaemia, claudication, and peripheral artery disease;
- Renal arteries – chronic kidney disease, hypertension;
- Coronary arteries – angina; or
- Carotid arteries – transient ischaemic attack (TIA).
Signs of ischaemia in the lower limb includes leg ulceration, cold extremities, pain on exercise, pallor of the skin, loss of hair growth on the legs, and reduced/absent pulses in the femoral, popliteal, posterior tibial, and dorsalis pedis arteries.
Blood Clots (Thrombus Formation)
Thrombi can form, not only when there is disruption to an atherosclerotic plaque, but also if there is other damage to the blood vessel wall (following trauma), abnormal blood flow (reduced mobility) or an abnormal concentration of blood clotting components in the blood. Venous thromboembolism (VTE) is when a thrombus forms in the veins and embolises (travels) to somewhere else in the body. These commonly develop in the deep veins of the lower limb as a deep vein thrombosis (DVT), and embolise to the lungs (pulmonary embolism) or brain (stroke).
Aneurysms
Blood vessels with weakened areas of their wall are susceptible to ballooning out, known as an aneurysm; although any blood vessel can develop an aneurysm, they most commonly affect arteries such as the aorta and cerebral arteries (brain aneurysm). Brain aneurysms will often lead to stroke. Aortic aneurysms form in the abdominal aorta (abdominal aortic aneurysm) and the thoracic aorta (thoracic aortic aneurysm). Abdominal aortic aneurysms (AAA) require regular monitoring to assess how stable they are and the indication for endovascular repair; a ruptured AAA is a medical emergency. Aortic aneurysms may also be associated with aneurysms in other locations, for example the iliac artery or popliteal artery. Thoraco-abdominal aortic aneurysms can also extend into the visceral and renal arteries and therefore present a more complex surgical picture. Open surgery may be performed to replace the segment of the aorta with a graft. Alternatively, the individuals may undergo endovascular aneurysm repair (EVAR) whereby a stent-graft system is introduced via the femoral arteries, relining the affected area of the aorta, and redirecting blood flow through the graft, allowing the aneurysm to stenose.
Aortic Dissection
Blood vessels may also develop tears in their walls. An aortic dissection is where there is disruption to the aortic wall and may be acute or chronic. Aortic dissections can be classified according to the extent of the aorta involved; the Stanford classification simply assesses whether the ascending aorta is involved, whereas the DeBakey Classification is more specific and addresses different sections of the aorta. Chronic aortic dissections can be managed conservatively with regular imaging. Acute aortic dissections are a medical emergency and require surgical intervention with stents and grafts or thoracic endovascular aortic repair (TEVAR).