Major venous Thrombosis

The major venous thrombosis , or phlebitis, or thrombophlébite, is with the pulmonary Embolie one of the two manifestations of the thrombo-embolic Maladie: a clot ( Thrombus ) is formed in the venous network of the lower extremities (venous thrombosis) and can second and migrate to a pulmonary Artère (pulmonary embolism).

Anatomy of the veins of the lower extremities

The venous network is made of two distinct entities between which exist communications.

the surface venous network is located under the skin, above the muscles ( known-aponévrotique ). Its function is the drainage of the skin and fabrics under the latter (subcutaneous). It is often directly visible. The abnormal increase in the gauge of the veins of this network forms the Varice S.
the major venous network drains the deep muscles and fabrics. It is known as under-aponévrotique because located behind the fibrous membrane separating the muscles from the skin (Aponévrose).

The communications between these two networks are made by veins known as perforating which, in normal conditions, allows exchanges only in the direction surface network towards major network.

The veins are provided in lower part with the fold of the groin (corresponding anatomically to the ligament inguinal) with valvules preventing the blood backward flow and the exchanges in the direction major venous network towards surface venous network and in the direction proximal vest the distality. These valvules have a decreasing density as one approaches the root of the members. They are also more numerous on the level of the major system. They thus impose the circulation of the surface system towards the major system and of bottom to the top (for a subject upright).

In the event of deterioration of the valves, destruction, absence (sterility) or inefficiency by dilation of the vein, one obtain a table of venous incontinence whose most visible demonstration is the formation of Varice S.

The major venous network

It is consisted the satellite veins of the arteries to the lower extremities. These veins take the name of the corresponding artery. They are, in general, two per artery in lower parts of the knee and single to the top. They are generally very close to the bones.

On the level of the leg (level sural):

former Veins tibiales in the antéro-external part of the calf;
posterior Veins tibiales in the posterior part of the calf;
peroneal Veins in the cabin (left) posterior
muscular Veins, including/understanding the twin veins and soléaires, respectively located within the twin muscles and soléaire (whose whole forms the triceps sural).

The meeting of the posterior and peroneal veins tibiales forms the tibio-peroneal trunk which is linked with the former veins tibiales to give rise to the poplitée Veine which can be duplicated in a third of the cases. The twin veins are thrown in the vein poplitée on the level of the hollow of the same name (back of the knee).

On the level of the thigh:

the surface femoral vein, principal collecting vein, being able to be duplicated
the deep femoral vein, additional collecting vein
the femoral vein common resulting from the meeting of femoral surface and deep to the level of the ligament inguinal, located at the fold of the groin. It receives the vein internal saphene, a little above, on the level of the Triangle of Scarpa. Its way is parallel to that of the Artère femoral and located in inside of the latter.

Above the fold of the groin:

the common femoral vein becomes external iliaque Veine then primitive iliaque Veine following its meeting with the iliaque Veine interns. The meeting of the two primitive iliaques veins on the level of the fifth lumbar vertebra giving rise to the lower Vena cava.

The surface venous network

The two principal veins of this network are the veins internal saphene (or large saphene) and external saphene (or small saphene).

the vein saphene interns is born compared to the malleolus interns (osseous outgrowth of the lower part and intern of the tibia above ankle) and walks on more or less vertically along the inner face of the lower extremity. On the level of the Triangle of Scarpa, it crosses a aponévrose, the fascia cribiformis , to link itself with the common femoral vein by forming a stick. This level exists a valvule, known as ostiale because located at its origin, preventing the venous blood of the common femoral vein from ebbing in internal saphene. The vein internal saphene receives throughout its way of many surface collateral veins. The incontinence of this valvule can oblige the surgical withdrawal of this vein saphene on the level of the stick ( éveinage and crossectomy ).

the vein external saphene is born with the level from the external malleolus (the osseous of lower part and external outgrowth of the Péroné located just above ankle) then walks on with the posterior face of the leg to bring together itself by a stick in the poplitée vein. However its anatomy is very inconstant and its variable termination (saphene internal, femoral deep, femoral surface).

In addition, it can exist a vein additional saphene or vein of Giacomini connecting the vein internal saphene and the vein external saphene.

Epidemiology

Major venous thrombosis is a relatively frequent disease. Its incidence is estimated at 0,5 cases per annum and by 1.000 people. It increases with the age to reach a rate of 3 new cases per annum and by 1.000 people in the octogenarians. It is slightly more frequent at the man.

Causes or risk factors

It begin with a clot in the venous system from the lower extremities. The formation of this clot is supported by:

the venous Stase, caused by an immobility involving the loss of the effect pumps muscular. This damning up is particularly marked in the event of prolonged confinement, but also in the event of long immobilization: plaster or long voyage by plane or car. It can be favoured by a low blood flow on a cardiac failure.
of the acquired biological anomalies: hormonal modifications (in particular association estroprogestatifs, standard pill, and tobacco), inflammatory diseases, Cancer S…
of the constitutional biological anomalies (of birth): deficit in certain factors (AT3, proteins C and S, Factor Leiden (also called resistance to the protein C activated)… This last anomaly being by far most current. These deficits will cause a repeating thromboembolic disease requiring a life treatment. They must be systematically required in the event of accidents repeated without found usual cause. To note that the regulation of Anticoagulant S will disturb the proportioning of these elements which can thus be made only before any treatment or with the stop of this last.

The diagnosis

Private clinic

The traditional clinical picture of major venous thrombosis includes/understands a pain of the calf which is sensitive, hotter, increased volume with presence of the sign of “Homans”: the dorsiflexion of the foot exacerbates the pain. The signs are however often rough and, in a significant proportion, non-existent.

One can palpate an hardened cord sometimes, under the skin, of thrombosis in the case of a surface venous thrombosis. The latter is much less serious because in general, does not evolve to the pulmonary embolism.

Three differential diagnoses are to be evoked:

a deep hématome: the anticoagulant treatment will worsen in this case the signs.
a erysipelas: subcutaneous infectious illness of the leg
a post-phlebitic disease: sensitive leg, with often of the apparent varixes, sometimes with a brownish skin of coloring (dermite ocher). The Doppler venous does not find any Thrombus but after-effects of an old phlebitis: dilation and venous valvular incontinence.

Biology

The proportioning of the D-Dimers , product breakdown of the fibrin which is one of the components major of the clot, makes it possible to make a diagnosis of elimination: a low rate makes far from probable the assumption of a thromboembolic disease , but an high rate does not make it possible to conclude since any disease, so much is not very inflammatory, increases its serum rate by them. In addition this biological proportioning less of value, spent 70 years, the rates which can be high at these ages without pathological significance and thus uninterpretable. However it should be remembered that the thromboembolic disease assigns the elderly more particularly.

The measurement of the TCK and the TP-INR are tests of the blood coagubility. They are made in a systematic way in order to check the absence of disease of coagulation, before beginning the anticoagulant treatment.

According to the table, one can seek from the start a constitutional anomaly of coagulation.

Imagery

The proof of the major venous thrombosis will be brought only if the clot is visualized.

the venous Doppler echography : made by doctors angiologists, it makes it possible to visualize and locate precisely the limits of the clot. It is an examination simple, painless, fast, stripped of dangers and extremely reliable. It is limited however a little more if the thrombus is located high (iliaque or cellar) because these structures can be badly visualized.
the phlebography : it was up to one recent time the examination of reference. One injected a product iodized in the veins of the back of the feet and one took a series of radiographic stereotypes. One could supplement the examination by a cavography by direct injection in the femoral vein with the fold of the groin. This examination involves the risks of any injection of products of contrast: allergy, impaired renal function. It could cause to him even a venous thrombosis. It is in practice current abandoned if one has venous echo-Doppler.
more incidentally, the scanner with injection makes it possible to visualize the vena cava well. It can be supplemented by a spiral thoracic scanner making it possible to make a pulmonary diagnosis of embolism.

Evolution of major venous thrombosis

Under a well led treatment, major venous thrombosis cures in the large majority of the cases without after-effects.

There exist however three types of complications:

the pulmonary Embolism
extension: the thrombus grows and goes up in the venous system, increasing the pulmonary risk of embolism.
the phlebitic disease post : occlusion partial or total of the major venous network makes that it is the surface network which deals with the venous return. The surface veins dilate, the valvules becoming incontinent then. It is the formation of the varixes with their functional procession: heavy pains, legs, trophic disorders cutaneous, oedemas…. These modifications increase the damning up and are the bed with the phlebitic repetitions.

Seldom a thrombus can migrate through an intracardiac communication right-hand side-left (of birth) and give an arterial embolism: it is about a paradoxical embolism .

Treatment of major venous thrombosis

The hospitalization is not necessary if venous thrombosis is simple and satisfactory conditions for a residence treatment.

In general, one employs an anticoagulant treatment under cutaneous ( Héparine of low molecular weight or HBPM ) in an injection with a relay by antivitamine K ( AVK ), begun as of the first day. The HBPM will be stopped only when the latter are effective and after 3 days of overlapping once INR target reached (between 4 and 8 days after the beginning of the treatment)

The rising is authorized as of the second or third day.

A venous application (bands or support stocking) is set up if possible at the first day and if not at least for the rising:

This application constrained the venous return to be done by the major network. It accelerates the repermeabilisation of this last and prevents the phlebitic disease post.
It must be absolutely posed above all to raise (except toilet and urgent need) and to be kept the day.
It must be carried several months.

AVK will be continued several months. In certain cases they will be prescribed with life (presence of a constitutional anomaly of coagulation or repeating phlebitis).

In the event of use of oestroprogestatifs (pill or substitute treatment of the menopause), the choice of the latter will have to be re-examined by the gynecologist.

The Tabac is strongly disadvised.

In rare cases, (If AVK are contra-indicated or if the thromboembolic disease repetition in spite of a well led anticoagulation), one can then propose the installation of a filter undermines :

a “sunshade” is assembled in the vena cava by low venous puncture (femoral) or high (chin-strap) in position under renal. This sunshade theoretically blocks the clots which cannot go up any more in the pulmonary arteries.
the risk of thrombosis of the vena cava is large with notable functional consequences (important disease post phlebitic bilateral).

Preventive medication

In certain situations, the risk of occurred of phlebitis is raised and justifies, consequently, a preventive medication. This risk can reach 40 to 80% after a surgery of the hip or knee and is in the neighborhoods from 10 to 20% at the time of a simple confinement during a hospitalization.

Preventive medication rests on an early rising, the possible port of an elastic application of the lower extremities ( support stocking ) and on the heparin administration with low molecular weights which can be relayed by anti-vitamins K according to the height of the risk.

The Aspirine does not seem to have shown effectiveness in long-term prevention at the people with bottom is likely to make a phlebitis.

Random links: