notes by dr Claudio Italiano
In the normal subject in an upright position, the venous return from the lower limbs is ensured, for a small part, by the venous tone, by the vis a tergo (ie by the residual push of the systolic impulse) and by the thoracic aspiration.
However, it is essentially the muscular contractions that drive the venous blood towards the right heart, while the valvular system prevents its reflux towards the bottom and towards the superficial network.
Anatomically the venous system of the lower limbs consists of deep veins (which run between the muscles) and superficial veins (which form a complex network just below the skin). The venous blood goes back along the lower limb, mainly through the deep veins and in a small part, through the superficial veins.
Tests with the lanyard for the practical evaluation
of superficial or deep continence of varicose veins
of the lower limbs
The heaviness and tiredness of the lower limb during prolonged standing,
the orthostatic edema, absent in the morning, detected in the evening, then the
eating disorders of the skin:
- pigmentation,
- hardening,
- ulcer,
characterize chronic venous insufficiency whatever the etiology. They are due to
hypertension and venous stasis due to backflow of blood, in a network with
insufficient valvular system.
The Trendelemburg maneuver assesses the continence of the saphenous
ostium; the patient raises the lower limb to 45 ° (with veins that become
collabite) and a tourniquet is applied to the root of the thigh, thus
compressing the superficial vessels; the patient then goes into orthostasis and
subsequently removes the snare: if the valves are insufficient, the veins tend
to fill up quickly from top to bottom; clearly it is not very applicable to the
setting of Intensive Medicine.
The Perthes maneuver assesses the existence of a deep vein occlusion,
from thrombophlebitis: a tourniquet is applied to the patient's thigh, who is
invited to walk; usually the superficial veins are emptied (the deep pathways
allow the venous discharge) while if there is a deep occlusion, the vascular
outflow is forcefully directed into the superficial circle, causing severe pain
in the calf.
In the essential varices, the main venous axis, deep, does not show any
important alteration.
Valvular insufficiency weighs on the superficial network, affecting either
saphenous vein, sometimes both and different perforating veins.
The varices become more evident during the erect position, they disappear when
the limb is raised.
The Schwartz sign, propagation of the wave caused by striking a section of the
blood column with a finger not segmented by valves, allows to specify the
topography of the varices and the main communication point that feeds them,
especially in fat subjects.
The passive hand appreciates, at the arch of the internal saphenous vein, the
reflux under the coughing and the propagation of the wave caused by the active
hand which abruptly strikes the most evident ectasias of the calf.
The examination of the external saphenous vein is performed on the patient
sitting with his legs dangling.
Each palpable venous cord is altered. The
Schwartz sign demonstrates the alteration of the external saphenous network. The
Brodie-Trendelenburg test highlights the valvular insufficiency.
It causes the varicose sagging by raising the lower limb and applying a rubber
tourniquet to the root of the thigh in order to compress the internal saphena
below the arch.
The patient is therefore invited to assume the upright position and after twenty
seconds the shoelace is removed. In the normal individual, the answer is
negative: with or without elastic, no vein is swollen.
In the varices of the internal saphenous vein due to isolated ostial valvular
insufficiency, the Trendelenburg test is positive. The varices remain emptied
until the string is kept in place and fill from top to bottom when it is removed.
In the varices of the internal saphenous vein, with insufficient communicating
veins (arch, perforators of the Hunter canal, perforating leg) the Trendelenburg
test is doubly positive: while the tourniquet is in situ the varices fill
moderately, through the distal communicants.
When the strap is removed, their distension increases, due to the reflux from the ostium. If the test is negative (stretched varices even during the application of the tourniquet, ndt) or doubly positive, it is advisable to repeat the maneuver (Delbet and Moquot) applying the lasso first above and after below the knee to specify the seat of insufficient communicants.
Finally, the lace is narrow under the knee to close the arch of the external saphena. If the varices remain loose as long as there is a lanyard it is a sign that they are fed by the external saphenous. If they are filled immediately, it means that they are fed by the piercings of the leg.
The age of the main venous axis, the deep, of the lower limb can already be clinically established when, despite the existence of voluminous varices, there is no orthostatic edema or there is little. The Delbet test provides a complementary confirmation easily. When the patient is standing, he places himself above the point where an insufficient communicating has already been identified, a lanyard that prevents reflux into the superficial venous circulation. After a minute of walking if the varices sag, it means that the blood they contained was drained through the deep pathway. By removing the lace they relax again.
The external break.
- Causes an abundant, continuous, persistent haemorrhage for both standing and
sitting patients. To stop it, it is sufficient to make the patient lie down,
with the leg very raised, and apply a compressive dressing.
- A varicose package or cord, first depressible and not painful, becomes hard,
painful, irreducible. It is thrombosed. The overlying skin becomes pink, warm,
oedematous.
To obtain the remission of symptoms and to avoid the complication of a deep
thrombosis, moist heat, active mobilization with raised limbs, short marches and
elastic compression are often sufficient.
The skin trophic disorders.
- Pigmentation, induration and ulcer are the consequences of stasis and regional
venous hypertension. The ulcer can heal if the venous stasis is suppressed:
- either with absolute rest in bed, with the leg raised.
- is outpatient, with a compressive bandage (in lastex or bandage with Unna's
glue) which holds a well-made dressing.
But only the removal of varices ensures lasting healing.
cfr anche index vascular surgery