Peripheral Vascular Disease (PVD)

Peripheral vascular disease is where there is an accumulation of plaque within the arteries supplying the lower limbs, manifesting in issues with walking (claudication) or wounds, ulcers or gangrene.

How does it occur?

Peripheral vascular disease is due to atherosclerosis. This is a condition where plaque accumulates in the wall of an artery. Atherosclerosis generally occurs in almost any artery. Its formation and insidious progression can take several years before clinical symptoms appear.

Atherosclerosis is a complex and evolving area of knowledge and understanding, but is thought to occur due to a variety of factors. These include poor diet, smoking, chronic inflammation, family history, dyslipidaemia and hypercholesterolaemia. Exposure to toxic agents causes inflammation that damages the lining of the artery wall. This then leads to platelet aggregation and low-density lipoprotein infiltration into the wall of the artery forming atherosclerotic plaques. The change in haemodynamic forces and continual exposure to toxins initiates a vicious cycle leading to larger plaques and narrowing of the artery which reduces perfusion to the food. This overall reduced blood flow will result in a range of symptoms from claudication to pain at rest, and eventually ulcers or gangrene.

Treatment

Treatment for PVD varies widely. In the first instance we generally investigate patients for disease with an arterial ultrasound scan or in some instances a CT scan to determine the extent of disease.

The initial treatment may involve observation and lifestyle modification with or without medication. The aim here is to reduce the risk factors of developing severe PVD. This includes controlling blood pressure and cholesterol, healthy diet and exercise to maintain healthy weight and smoking cessation.

What are key-hole surgical options to improve blood flow to the leg?

In the first instance we often embark on minimally invasive treatment. Treatment can include angioplasty (ballooning), stenting or atherectomy (minimally invasive extraction of plaque). Some of the reasons for treatment may include lifestyle limiting impairment in walking, pain in the foot at night interfering with sleep, or wounds, ulcers or gangrene. Many of these procedures can be completed using light anaesthetic (sedation) and most will require an overnight stay in hospital.

An angiogram is a keyhole procedure whereby the vascular surgeon will puncture the femoral artery in the groin and place a plastic tube within the vessel (sheath). Contrast is then injected into the sheath, and with the use of x-ray imaging the location and severity of the disease can be identified. Sheath sizes range from 4 Fr to 9 Fr for standard interventions with a variety of lengths from 6cm to 65cm. This allows for balloons and stents to be inserted to treat the atherosclerotic plaque.

On completion of an angiogram, when the sheath is removed, bleeding will occur. This can be stopped by using finger pressure over where the sheath was inserted or a special device that is used to close the hole in the artery.

Balloon angioplasty and stenting

Balloon angioplasty is a keyhole procedure whereby balloons are used to open the narrowing caused from atherosclerosis. Technically wires are used to find a channel across the plaque allowing for the insertion of the balloon. This is all done through the sheath. There are several balloon sizes and types that may be used. These include plain balloon, drug coated balloons, high pressure balloon and cutting balloon.

Sometimes the artery can recoil and re-narrow and patients require more than one procedure. Stents may be used in addition to balloons to help improve blood flow when ballooning has failed. These are also inserted from the sheath and remain within the artery.

Specialty key-hole intervention – Atherectomy

Atherectomy involves the use of a special device that is inserted within the artery via the sheath that physically extracts plaque from the vessel wall. There are several devices that can be used that either shave plaque or drill a hole through the plaque to create a new channel for blood to flow down to the foot.

What are surgical options to improve blood flow to the leg?

In some instances, we may recommend that the best of course action is open surgical bypass. This requires a general anaesthetic and involves making a large incision along the affected leg to replumb the arteries. Ideally the patients own vein (either from the leg or arm) is used as the graft to bypass the blockage within the artery. Once the vein has been harvested, strong blood thinners are given while each end of the vein graft is attached above and below the blockage. This now provides an alternate route for blood to flow down into the foot. If the patient does not have long enough vein or poor quality vein, then a synthetic material can be used for the bypass graft. The average stay in hospital following a bypass is 5 days.

Risks associated with leg angiogram and surgery