It should be emphasized that, despite available scientific The severity, localization and duration of the outflow dis-
evidence, the above descriptions are in many respects still order and the degree and duration of stress on the leg
only a theoretical model and that the highly complex vein system determine the variable clinical presentations
physiological functional processes and relationships have which appear gradually and with inexorably increasing
to date only been partially elucidated. It is certain, how- severity. This complex of clinical signs is subsumed under
ever, that the complex functional unit - known for the the general term chronic venous insufficiency (CVI) and is
sake of simplicity as the calf-muscle pump - is at the cen- usually assigned to three grades of severity according to
tre of a programmed sequence of events that takes place the Widmer classification.
during movement.
Grade I chronic venous insufficiency is characterized by a
If the return of blood to the heart is disturbed (venous collection of dilated venules (corona phlebectatica) and
insufficiency), less blood is withdrawn from the upstream edema around the ankles and above the arch of the foot,
venous segments and the fall in venous pressure is less and by ankle edema.
pronounced (venous hypertension). The overload on the
veins acts as a backward decompensation extending as Grade II manifests as hyperpigmentation of the skin,
far as the capillaries of the terminal vessels. The low pres- lower leg edema and dermatoliposclerosis. The skin is
sure values necessary for a properly regulated exchange then firmly bonded with the lower leg fascia, cannot be
of substances then cannot develop, and venous flow raised in folds and has a more pronounced sheen than
slows down or even ceases completely. The metabolic usual. An extreme form of dermatoliposclerosis is atro-
processes, especially in the subcutis or cutis, are phie blanche (also known as capillaritis alba or white
impaired. Eventually, the lymphatic system is also affect-
ed, and is only able to compensate the increase in inter-
1) Pronounced dermatoliposcle-
stitial fluid in the initial phases of an outflow disorder by
rosis in Grade II CVI, due to
increasing fibrosis of the cutis
increasing the flow of lymph
and subcutis
2) Atrophie blanche with the
The earliest recognisable consequence of this disordered
white atrophic skin changes
condition is edema, which leads to further increases in
3) Florid venous leg ulcer in
Grade III
pressure and accumulations of fluid and thereby further
4) Ulceration covering the gaiter
exacerbates the already compromised metabolic situation.
12
area of the leg
Further consequences are fibrotic, degenerative and
inflammatory processes associated with trophic skin alter-
ations. Finally, obliterative inflammatory processes in the
venules and arterioles lead, initially in regions with
unfavourable venous hemodynamics, to the development
of venous leg ulceration as the now visible sign of
decompensated venous hypertension.
3 4
Causes [10.11]
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