Phlebectasia

PHLEBECTASIA, dilation of the lumen of a vein. Phlebectasias are subdivided into several types. Rokitansky distinguished: 1) cylindrical dilations of veins with preservation of the normal properties of the wall, with its thinning and thickening; 2) focal phlebectasias of the varicose type. Virchow distinguished simple ectasias, varicose ectasias, ampullary ectasias, dissociating ectasias, and cavernous ectasias. Benda distinguishes diffuse ectasias of the cylindrical or serpentine type, diffuse ectasias but with uneven swellings of the varicose type, and localized tumor-like ectasias of the venous angioma type. In practical medicine, the question of varicose vein dilations is considered separately, but Benda asserts that there are no varicose vein dilations without dilation of the vein along its entire length. The analogy with aneurysms of arteries that are not entirely changed is not applicable, as these are essentially two completely different processes. In the pathogenesis of phlebectasia, the primary factor is a change in the state of the muscular part of the venous wall. Even ruptures of elastic fibers do not have an effect on the width of the lumen, and the tone of the venous wall does not drop because of this. The conditions that change the properties of the musculature of the vein wall can be various. Degenerative and atrophic processes of the vein musculature can lead to phlebectasia, and in these cases, phlebectasias are, as it were, primary. Functional and mechanical factors, which occur in liver cirrhosis, heart defects, and ligation of veins during operations, are accompanied by the dilation of existing veins and the formation of new ones, and in these cases, hypertrophy of the musculature of the venous wall is observed. Subsequent insufficiency of the hypertrophied venous wall can further increase the already existing dilation of the vein. Phlebectasias can also be observed during physiological states; for example, in the pregnant uterus, there is both hypertrophy and dilation of veins. The analysis of the conditions for the emergence of phlebectasia often encounters great difficulties. For example, the development of phlebectasia in the upper part of the thigh against a background of stasis testifies to the absence of parallelism with the greatest mechanical pressure. The development of phlebectasia of the angiomatous type generally has no explanation in a number of cases. The question of phlebectasia with varicose dilations on the lower extremities in pregnant women is being re-examined. The view according to which these phlebectasias developed from the compression of the vein by the pregnant uterus is disputed, and the development of phlebectasia is explained rather by the influx of blood to the lower part of the trunk (Kownatzki). The practical significance of phlebectasia is determined by the conditions of their development and localization. Collateral phlebectasias of the caput medusae type or phlebectasias in the wall of the esophagus and the fundus of the stomach during liver cirrhosis are often the cause of fatal hemorrhage, for example, during punctures of the abdominal wall, during the introduction of a stomach tube, or spontaneously. Active methods of treatment are used mainly in the presence of varicose dilations of the veins of the extremities and the scrotum (see Varicose Veins), which is apparently the main reason for separating them into a special chapter. Literature—see literature and the article Veins.