Peripheral Vascular Disease

Basic anatomy of the lower limbs

 

The large caliber abdominal aorta (1) terminates by forking (bifurcation) into two large common iliac arteries (2) that have practically no side branches.

Each of these arteries also bifurcates into branches: The internal iliac artery (3), also called the hypogastric artery, that supplies all the organs of the pelvis and the genitalia with blood, and the external iliac artery (4).

The common femoral artery (5) is a continuation of the external iliac artery. It lies at the root of the thigh and is the most frequently used artery for arterial approach in all diagnostic and interventional procedures.

The common femoral artery rapidly divides into the superficial femoral artery (6), which runs on the interior part of the thigh and has few if any sidebranches, and the profound femoral artery (7) which is responsible for supplying blood to all muscles of the thigh.

The superficial femoral artery is continued by the popliteal artery (8), which passes to the calf behind the knee joint.

In the superior (upper) part of the calf, the popliteal artery divides into three branches (two tibial arteries (9) and one interosseous artery), which are responsible for supplying blood to all the muscles of the calf.

All three of them descend to the leg where they form an anastomotic plexus that supplies blood to all local tissue.

PVD is a common circulation problem in which arteries that carry blood to the arms or legs become narrow or clogged and the blood flow gets slower or stops.

Diminished blood flow to a part of the body may cause discomfort because the blood carries essential substances such as oxygen and nutrients to all the cells.

If the blood flow to a certain part of a limb stops completely for a few hours, that part may suffer up to irreversible damage.

This phenomenon is called gangrene and the only available treatment is amputation.

Interventional Radiology

Background and history

• The first therapeutical application of cardiovascular catheterization was invented by Charles Dotter and Melvin Judkins in 1964.
• They developed an intravascular catheter system that could be advanced inside a peripheral artery to the site of an atherosclerotic narrowing, in order to relieve it by dilatation.
• The procedure developed rapidly at the beginning of the 80s and as more and more physicians were trained to apply it, a lot of experience in using it was gained.
• Today peripheral intervention techniques are the most widely used procedures in treating peripheral atherosclerotic artery disease by a non surgical method.
• Interventional radiologists are specially trained doctors who use x-ray and other imaging techniques to “see” inside the body and diagnose Peripheral Vascular Disease (PVD). They use special methods of treatment that may avoid surgical interventions.
• These methods of treatment are minimally invasive and gain access to major vessels by puncturing peripheral arteries and/or veins.
• They guide long narrow tubes (catheters) through the blood vessels to access the diseased part of the vessel involved.

Some advantages of interventional radiology

• Low operating risk in patients with associated severe vascular or systemic disease such as severe brain and/or coronary atherosclerosis.
• Less traumatic than surgical intervention (involving small incisions no larger than the lead tip of a pencil).
• Low operating risk in patients with associated severe vascular or systemic disease such as severe brain and/or coronary atherosclerosis.
• Lower mortality and morbidity.
• Peripheral Transluminal Angioplasty (PTA) with or without stenting, has been clearly demonstrated to reduce the rate of amputation in 86% of patients that have suitable lesions for interventional treatment.
• General anaesthesia is usually not required; the procedures are performed with local anaesthesia given by injection at the site of the vascular access.
• Less painful, as lesions are much smaller.
• Shorter hospital stay.
• Less expensive than surgical procedures depending on the type of materials used to treat a particular illness.

What is the difference between:

Peripheral Intervention
An interventional radiologist uses x-rays and other imaging devices to guide thin catheters and other small tools through the peripheral arteries to treat an illness without having to open up an area over the diseased part of the artery.
Conventional vasular surgery

Conventional vascular surgery
A traditional surgeon makes an incision (a cut) to open up an area of the body. He or she looks directly at the diseased segment or organ and repairs it.

Peripheral Stents

Background

Intravascular peripheral stents were developed to adress the limitations of balloon angioplasty including acute complications and unsatisfactory results that occurred in peripheral interventions.

What is a peripheral stent?

A peripheral stent is a small vascular prosthesis (tube) consisting of stainless steel, nitinol or titanium wires.

These wires are specifically designed so that the stent can be mounted on deflated balloon catheters. Positioning the deflated balloon with the unexpanded stent mounted on it inside a diseased vessel and inflating the balloon at high pressure deploys the stent against the vessel wall.
The stent remains in the vessel acting as a scaffold to keep the vessel open.

Stents are classified according to their design, basic material they are made of, or the method of deployment. The type of stent used, (diameter, length, and manufacture) should be left to the operating doctor to decide, as he/she is the only one that can best judge all the parameters.

When are peripheral stents used?

If a vessel does not respond properly to balloon inflations and remains narrowed or does not open enough, it might be necessary to implant a stent. Stents were developed to reduce immediate recoil of the vessel narrowing and to improve immediate and long-term results of Percutaneous Transluminal Angioplasty (PTA) mainly in anatomically unfavorable narrowings.

Peripheral stent placement

A peripheral stent can be implanted in the peripheral artery at the time of PTA. It acts as a scaffolding device, which remains in the treated artery to ensure the passage of blood for a longer period.