Note by dr Claudio Italiano
The arterial system of the femoral-popliteal-tibial axis is responsible for the vascularization of the lower limbs. As in the other vascular districts of the organism, the arteries of the lower limbs can also be affected by atherosclerotic pathology. By atherosclerotic pathology we mean the formation of fat and calcium deposits on the innermost layers of the artery. The formation of these bearings can lead to narrowing (stenosis) or complete closure of the artery (see chronic peripheral obstructive arterial disease), with consequent decrease or even arrest of blood circulation in the affected districts.
There is a first stage of the disease in which the narrowing of the artery is present, but it is not yet such as to cause symptoms. In the second stage of the disease, reduced circulation leads to the appearance of pain in the lower limb during muscular effort, such as walking. This painful symptomatology, which always arises during physical activity, is completely resolved by the cessation of the muscular exercise itself. With the progression of atherosclerotic disease the pain in the leg appears due to increasingly smaller efforts, therefore also for shorter and shorter walks.
In the third stage of the disease there is the appearance of pain even at rest, therefore without the execution of any muscular effort. The last stage of illness (fourth stage), the most serious, leads to the formation of necrotic lesions on the leg and the foot, which can lead to amputation. From what has been illustrated, it is possible to understand how atherosclerotic pathology is a multi-departmental one, that is, it can affect all arteries, in every district, and above all it is a progressive disease, continuing gradually to worsen until the limb is lost. The first step in the study of atherosclerotic disease is the complete assessment of the degree of disease and the extent of the degree of stenosis of the arteries. To do this, in addition to the clinical examination, an instrumental evaluation of the degree of artery obstruction with EcoColorDoppler, angiography and possible angioTC are important. Obviously the first attempt at treatment is carried out by means of medical therapy based on antiplatelet and vasodilating drugs, ie drugs whose purpose is to make the blood more fluid, to dilate the arteries already restricted by the evolution of the disease to the maximum degree. and to strengthen the collateral circle.
They are candidates for surgical intervention:
• patients with leg pain due to minor muscular efforts, such as walking less
than 50 meters, or presenting vascular pain even at rest, or gangrene.
Surgery is designed to make blood circulation possible again at the level of the
artery that is narrow or completely closed. This is possible through two
distinct surgical techniques:
In case the atheromatous disease is segmental, ie well localized in a short
arterial stroke, leaving the upstream and downstream artery portions intact. It
consists in the isolation and incision of the affected artery as well as the
cleaning of the cholesterol and calcium deposits present in it, with subsequent
artery suture. This intervention is used quite rarely due to the frequent
multiplicity of localizations of the disease. It is an intervention particularly
indicated in young patients as it does not preclude the possibility of a
subsequent by-pass in case of progression of atherosclerotic disease. It does
not involve the use of prosthetics and has better prospects in time.
-BY-PASS used in the case in which the stenosis or the occlusion is extended to
a long or hardly accessible stretch of artery. By bypass we mean the
interposition of an "artificial artery" between the upstream healthy artery
segment and the healthy artery downstream of the obstruction. The blood flow is
then conveyed into a duct positioned in such a way as to overcome the obstacle
represented by the narrow artery. Based on the flow obstruction sites, some
types of by-pass are distinguished:
-BP aorto-bifemoral: involves the
insertion of a bifurcated prosthesis in the anatomical space normally occupied
by the aortic bifurcation, ie the retroperitoneum. The by-pass is interposed
between the aorta and the bilateral femoral arteries. The intervention almost
always requires the use of general anesthesia.
-BP femoro-popliteus: involves the interposition of a prosthesis between the
common femoral artery and the popliteal artery above the knee (supragenicular)
or below the knee (subgenicular).
Surgery can be performed, as well as under general anesthesia, also in
loco-regional anesthesia.
-BP Extra anatomical: provides the revascularization of the lower limbs using a
donor artery and a by-pass path that are different from the natural ones. The
routes used are generally superficial, making the intervention simple and
scarcely traumatizing for the patient.
In the axillo-bifemoral by-pass the prosthesis is interposed between the
axillary artery and the common femoral arteries, either mono or bilaterally. The
prosthesis runs subcutaneously at the level of the thorax until it reaches the
groin. In the femoro-femoral by-pass the prosthesis runs from the femoral artery
from the healthy side to the femoral artery of the other side. It is used in the
case of unilateral iliac artery obstruction. The prosthetic material used may
consist of "biocompatible" synthetic material or an autologous vein taken and
prepared during the same procedure; generally the great saphena vein is used,
but also other venous segments can be used, if necessary.
Complications include:
• thrombosis of the by-pass, that is, occlusion of the prosthesis. It always
requires a surgical review. It has incidence varying from 2% to 7% in relation
to the type of packaged by-pass and the type of prosthesis used. It can lead to
amputation;
• postoperative hemorrhage; it occurs at a percentage lower than 2%;
• appearance of lymphocele, or a lymph collection in the inguinal surgical wound.
It is a relatively frequent complication, but generally of spontaneous
resolution;
• prosthesis infection; it is an extremely serious complication that manifests
itself in a percentage around 2%. To obtain the resolution of the infection it
is often necessary to remove the prosthesis with serious consequences on the
circulatory conditions of the limb. It can lead to amputation;
• edema, ie swelling of the operated limb; it is due to the circulatory and
lymphatic alteration consequent to the surgical intervention. Generally there is
spontaneous resolution of edema within a few weeks of surgery. Sometimes it is
necessary to use elastic supports or bandages. The overall mortality of the
intervention is between 0.5% and 5% determined mainly by cardiology and
respiratory complications.
Link on pathologies of the arteries
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