Hcemorrhoids, in their relation to sis, consist merely of dilated veins, situated in the vicinity of the anus, and in which chronic inflammation and thickening of the external coat and surrounding areolar tissue is very conspicuous. The dense covering of areolar tissue, and the comparative smallness of the enclosed vessel's calibre, have given rise to different explanations of the pathological origin of piles.
Le Dran, Racamier, Delaroque, Cullen, Chaussier, and others have considered them as encysted coagula of extravasated blood. Delpech and Crnveilhier describe them as tumours of erectile tissue. But by far the most numerous and reputed pathologists, among whom may be mentioned Andral, Stahl, Petit, Morgagni, Hodgson, Lobstein, Froriep, and Brodie, concur in the now gene rally received doctrine of the origin of hm morrhoids in varicose veins.
Hmmorrhoids consist of oval, ovoid, or round masses with broad bases, situated either just within, or just without, the sphincter ani. On examining the texture of these tumours, they are found to consist of cells or cavities of various sizes, surrounded by layers of red, dense, areolar tissue. These, which vary in shape, are lined internally by the smooth lining membrane of the vein, and are perfor ated here and there with the apertures of small communicating and tributary veins.
The absolute continuity of these cells with the venous cavity has been proved by Hasse and Brodie, who have injected them from the arteries ; the former has also injected them by the veins.
They are very apt to inflame and become lined with lymph, or stuffed with coagula.
Varices occur in all situations and in every variety : instances are on record where they have occurred in the veins of the (esopha gus, lips, eyelids, bladder, heart, &c.: indeed there .appears to be no region which is free from the occasional development of this dis ease.
Rupture or Perforation of Veins.—A number of pathological examples, in which perforation of the vessel's walls is the conspicuous cha racter, may be conveniently, though, it must be confessed, not very naturally, classed under this head. Either with or without previous change, and that change very various, the lesion may occur, so that the only condition common to these instances of morbid change is a breach in the venous cylinder.
A rupture, without previous morbid change in the vessel, and which may occur in any case where the tissues of the vein are thin and weak, may be produced by an unusual amount of intermit tension of the contained fluid. So again, an attenuated or ulcerated state of vein may yield before an amount of distension that is neither excessive nor unusual : rupture is the result in either case.
Destructive disease may, as well in veins as elsewhere, attack the tissues of the organs in question, — suppurative inflammation, ulcer ation both extrinsic and intrinsic, extension of malignant disease, &c.: perforation is here the issue.
In the rupture of a previously healthy vein the change consists in a rent or tear of the structure, the surrounding tissues being nor mal : the rent is sharp, and more or less re gular. In perforation from ulceration, &c. the aperture is rough, irregular, and jagged; the parietes of the vessel are thinned down towards the hole, are much thickened more remotely, and the orifice is ragged and shreddy.
Sudden or extreme obstruction to the cir culation, thus causing excessive distension, has produced rupture of the healthy veins. Bichat mentions instances of rupture of the veins of the lower extremities during preg nancy ; Lee, those of the labia during labour. Violent muscular exertion has ruptured veins, by producing local congestions : Hodgson, for example, has witnessed rupture of the veins of the leg during cramp of the gastrocne mins ; I have three times seen rupture of a vein on the dorsum of the foot during strong exertion. Andral narrates an example where, during a violent struggle, the vena cava in ferior was ruptured ; " the borders of the perforation seemed as if they had been torn asunder, and the coats of the vein in the neighbourhood were perfectly healthy." The peculiar bloodlessness of the surface, and con sequent deep-seated congestion which occurs during rigors or the sudden application of cold .
to the surface, has ruptured the large internal veins. Portal tells us of a case of rupture of the vena cava superior from a patient getting into a cold bath : and Senac mentions the rupture of the large internal veins as occurring in the rigors of intermittents.