Only 1.1% of males and 2.2% of females are hospitalized for surgery on the varices of the lower limbs. The most frequently affected sites are represented by the superficial veins of the lower limbs.
and its collaterals (see: vein anatomy); if you want to extend the concept even to modest varicosities of only aesthetic importance, this figure reaches 35%. There is a notable difference between the various countries: the disease is much more frequent in Europe than in Africa or Asia, where there is a 10 times lower prevalence., which hinders the return of venous blood upwards
The factor that most affects venous blood pressure is posture; during the standing position, especially if prolonged, the venous pressure increases considerably, up to ten times the normal pressure. Consequently, occupations that require an upright posture for long periods of time or long journeys by car or plane, often lead to the onset of marked venous stasis and the appearance of edema (swelling due to the presence of fluid) on the feet. . Varicose veins are much more frequent after 50 years of age, in obese people and especially women, due to the high venous pressure that pregnancy causes in the lower limbs. In addition, the high levels of estrogen present in women, facilitate relaxation of the venous wall musculature The familial tendency seen in varicose vein disease is believed to be due to impaired development of the venous wall.
The real cause of the dilation of the lower limb veins, however, has not yet been defined; there are basically two hypotheses for which the valves and the structure of the venous wall are held responsible, respectively. The hypothesis of valvular degeneration today seems difficult to sustain: ultrasound techniques have made it possible to highlight how the branches of some veins of the lower limbs can undergo varicose degeneration even when there is good valve continence. therefore facing the structure of the varicose vein wall, in which there seems to be less collagen and elastin than in the normal venous wall.
If there are varicose veins with valvular insufficiency of the saphenous vein systems and communicating veins, part of the blood pushed towards the heart during walking tends to flow back into the superficial circulation and from this to pour back into the deep circulation, thus implementing a vicious circle. The hemodynamic effect of this mechanism consists in a lower drop in walking pressure of 20 centimeters of water and in a faster recovery of the basal pressure values of 80-100 centimeters of water. Failure to reduce venous pressure during exercise muscle is the basis of almost all diseases of the venous system, both superficial and deep, and as such represents a risk factor for varicose veins.
Other articles on "Varicose varicose veins"
- Anatomy of the veins
- Varicose veins: causes and classification
- Varicose veins: symptoms and diagnosis
- Varicose veins: treatments and therapy
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