Occlusion of the arteries of the lower limbs
Atherosclerosis frequently causes obliterating arteriopathy, which most often affects the lower limbs (PAAD). This chronic disease affects approximately 20% of the population over 65 years old. It is characterized by the narrowing or occlusion of an artery in the lower limbs, which causes poor perfusion (ischemia) of the tissues.
What are the symptoms of atherosclerosis?
Symptoms vary depending on which artery is affected and the degree of decreased blood flow. Sometimes the occlusion or stenosis of the artery (i.e. the reduction in its caliber) is discovered accidentally while the patient does not feel any discomfort. The patient is then said to be asymptomatic (who does not present symptoms).
Sometimes the patient feels pain that only appears when walking. It is then defined as limping. Claudication is a muscle cramp that results from a lack of oxygen supply during exercise. The patient must stop their activity for a few minutes until the cramp disappears. Depending on the artery affected, the cramp is located in the buttock, thigh, calf or foot.
Sometimes the drop in blood flow is so great that the tissues in the leg lack oxygen and nutrients even at rest. The patient then presents with foot pain. These mainly appear when he is in a lying position. Typically, they wake the patient during the night, who then has to put their feet out of bed or walk for them to disappear. In advanced stages, the skin suffers so much from lack of blood that sores may appear. These do not heal because the blood no longer provides enough nutrients for healing. These wounds sometimes become infected, the final stage being gangrene. Pain at rest and non-healing wounds are defined as critical ischemia.
How to make a diagnosis?
Clinical examination often allows us to suspect obliterating arteriopathy of the lower limb. The limb is cold, pale and pulses are not palpable. A comparison of blood pressure in the arm and ankle allows the diagnosis to be made with certainty.
If the symptoms are serious enough to consider intervention, an assessment of the leg arteries is carried out by the angiologist using an ultrasound and measuring blood pressure in the foot. Often, to be able to plan the intervention, a CT scan or an MRI will be carried out in addition by the radiologist.
The surgical indication
Surgical interventions are not performed on asymptomatic patients, except in rare situations.
In the event of claudication, the indication for surgery depends on the disability felt by the patient. It is generally accepted that there is reason to intervene if the latter cannot walk more than 200 meters without stopping. However, if the patient can walk more than 200 meters but judges that the disability justifies taking the risk of an intervention, this is discussed with the surgeon. Conservative treatment by gait training, under the supervision of an angiologist, is sometimes sufficient to increase the walking distance and thus avoids intervention.
In the event of critical ischemia, we always operate because the viability of the leg is at stake.
Vascular rehabilitation and gait training program organized by the Angiology Department
Operating techniques
Two techniques are available:
1. Surgical technique
2. The endovascular technique.
Surgical technique for atherosclerosis
This technique consists of reaching the diseased artery through skin incisions to clean it by directly removing the atherosclerotic plaque or to short-circuit it by performing a bypass. A bypass involves replacing the diseased artery with a segment of synthetic tube, called a prosthesis, or with a vein. This technique has the advantage of presenting very good long-term results. On the other hand, it requires skin incisions, sometimes large, which make the immediate surgical risk and convalescence more significant than for the endovascular technique.
Endovascular technique for atherosclerosis
This technique consists of reaching the diseased artery by passing through the interior of the arteries. A puncture through the skin is made at a healthy artery, normally in the groin, then a metal wire, called a guide, is led to the diseased artery. Balloons are guided over this guide and dilated at the level of the diseased artery to re-open it. If this is not enough, a small metal spring, called a stent, will be deployed in the artery to keep it open. This technique has the advantage of being minimally invasive. It can even be performed under local anesthesia on an outpatient basis. However, it presents worse long-term results than surgery and requires more interventions.
In certain situations, the two techniques can be mixed. This is the so-called hybrid technique. Each patient being unique, their choice is decided according to the topography of the lesions, the patient's state of health and their expectations. Together, the patient and the surgeon decide on the most suitable treatment.
Source: www.chuv.ch - vascular surgery department
