The aorta originates from the left ventricle of the heart and extends down into the abdomen where it bifurcates into the common iliac arteries at vertebral level L4.

It can be divided into the following sections:

The majority of abdominal aortic aneurysms (AAAs) originate below L1/L2 – the origin of the renal arteries – and above the bifurcation of the abdominal aorta. Although thoracic aortic aneurysms also occur, these are much less common and do not feature in exams as much as AAAs.

There are two common carotid arteries which provide the majority of the blood supply to the head and neck:

The carotid arteries are contained in the carotid sheath and are positioned posterior to the sternocleidomastoid muscles in the neck. They are found in close proximity to three cranial nerves:

During carotid endarterectomy, these nerves are at risk of damage. Damage may cause:

The femoral artery is the main blood supply to the lower limb, and hence its occlusion can result in gangrene and the need for amputation if untreated. It is a continuation of the external iliac artery (a branch of the common iliac artery).

The popliteal artery, a continuation of the femoral artery, runs through the popliteal fossa, ending at the lower border of the popliteus muscle. It divides into the anterior and posterior tibial arteries to supply the leg.

It has five genicular branches, which anastomose with branches of the lateral femoral circumflex artery (from the profunda femoris) and the anterior tibial to supply the knee joint. If the femoral artery must be ligated due to the presence of an aneurysm, this anastomosis ensures that blood will still reach the leg. A femoropopliteal bypass operation is used to ensure limb survival in the case of a popliteal aneurysm.

The great saphenous vein is the longest vein in the body. It originates from the dorsal venous arch of the foot and passes in front of the medial malleolus of the ankle, running medially up the leg and anteriorly up the thigh before passing through the saphenous opening of the fascia lata to join the femoral vein.

The great saphenous vein is the most common vein to be used by vascular surgeons as a conduit in bypass operations.

Peripheral vascular disease (PVD) is obstruction of the peripheral arterial blood flow. This definition therefore excludes the intracranial and coronary arteries. In some patients PVD may be mild with only asymptomatic plaques present. Others may suffer from moderate disease and present with intermittent claudication (IC). Finally, severe disease is likely to present as critical limb ischaemia (CLI), which may result in amputation. Both the presence and severity of PVD is determined by the ankle-brachial pressure index (ABPI). In health the ABPI is greater than 1 mmHg.

The main risk factors for PVD include:

Considering mild disease is mainly asymptomatic the majority of patients present with IC as a result of moderate lower limb ischaemia. The ABPI is typically 0.5–0.9 mmHg. Patients complain of muscular pain in the calf, although pain may also be felt in the thigh and buttocks. Pain is provoked by exercise, most commonly at a ‘claudication distance’ and relieved by rest. Symptoms often follow a cyclical pattern in which they progress then resolve as ischaemia promotes the development of collateral vessels. PVD can be managed conservatively by risk factor reduction strategies, including smoking cessation and supervised exercise programmes. If conservative measures fail vasoactive drugs can be used. Some patients ultimately require surgical treatment.

Stenosis of the carotid arteries in the neck is caused by atherosclerosis and plaque formation. The plaque(s) may be stable and asymptomatic or be the source of embolization. As the embolus travels into the intracranial vasculature it may cause temporary ischaemia resulting in a transient ischemic attack (TIA) or manifest as a thromboembolic stroke resulting in permanent damage. Carotid artery disease may present as a carotid bruit (‘swooshing’ noise) on auscultation. Colour flow duplex ultrasound is the diagnostic modality of choice.

The main risk factors for carotid artery disease include:

If there is a greater than 50 % stenosis of the internal carotid artery on investigation which has resulted in a TIA or stroke, the first line treatment is urgent carotid endarterectomy. This is only indicated within 14 days of the event. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) has reported that carotid endarterectomy provides significant benefit in patients with severe symptomatic stenosis [1]. If the stenosis in the internal carotid artery is found incidentally and is asymptomatic, the evidence for surgery is less clear. The asymptomatic carotid surgery trial (ACST) found that while the procedure reduces stroke risk in asymptomatic patients younger than 75 years, benefit to patients depends on a variety of factors including life expectancy and future surgical risk [2]. Current management options in asymptomatic disease also include medical alternatives.

There are both superficial and deep venous systems in the lower limb. They are connected to each other by perforating veins and at the sapheno-femoral and sapheno-popliteal junctions. Venous blood is returned to the heart via the iliac veins and inferior vena cava.

When the calf muscles in the legs contract blood is pumped towards the heart as venous blood drains from superficial to deep veins. When the calf muscles relax the ‘one-way’ valves in the veins close. This closure prevents backflow of venous blood into the superficial venous system.

Valve incompetency will allow blood to flow into the superficial veins, converting them into a high-pressure system and producing the enlarged, tortuous appearance of varicose veins.