Immediately under the skin lies the cellular tissue, which is a part of the general cellular investment of the body, and is here known as the superficial fascia of the leg. It is gene rally pretty thick, and is easily dissected back in amputations. Placed between two solid layers, the aponeurosis and skin, it easily in flames and may become the seat of extensive inflammation and abscess. When the inflam mation has terminated in gangrene, the slough ing process in this cellular tissue is very rapid and often very uncontroulable ; and where this destruction has occurred to considerable ex tent, in the after process of reparation the new cellular web is so short, close, and inelastic, as to materially impede the freedom of movement in the limb. When pus has been formed, the facility which the loose texture of the super ficial fascia offers for its spreading in all direc tions, points out the necessity for early and free incisions through the integuments ; and even before this stage of the inflammation, and while it is in its most active state, the same bold practice offers us the best means of arresting its progress. This cellular layer is the seat of the effusion in phlegmonous erysipelas, ana.sarea, phlegmasia dolens, and partially so in ele phantiasis. The distension which this tissue and the integument over it undergo in the dis eases just mentioned, is occasionally enormous, and affords a striking contrast between the elastic properties of the natural and adventitious structures. When anasarca distends a leg upon which an old cicatrix exists, the newly formed cellular web of this part is so little elastic and so little admits the fluid into its cells, that a considerable depression is seen here in the midst of the general swelling.
Imbedded in this superficial fascia we find a number of veins which are various in size, none very large in the natural state, numerous, and here possessed of more surgical interest and importance than in any other superficial region of the body. They are principally ar ranged in two sets ; one commencing about the inner ankle, and running along the inner side of the calf, terminates just below the knee by one trunk called the internal or major saphena. The other set form the saphena minor, by coming from the outer ankle, along the outer and back part of the leg, and termi nating in the popliteal vein in the middle of the ham. This vein is superficial only in the lower two-thirds of the leg ; after this, it passes through the layers of the aponeurosis, and runs under it till its termination. This is the more ordinary course of them, but no part of the circulating system is more various than these superficial veins in their divisions and arrange ment. These veins, by becoming varicose, frequently occasion great suffering to the pa tient, and annoyance to the surgeon, by the difficulty of their cure. The saphena major is more liable to this state of disease than the minor; indeed few persons whose habits are to be much in the erect posture appear to attain middle age without being more or less troubled by it.
The deeper seated veins, which accompany the arteries, lie imbedded among the muscles, and from them receive considerable pe.ssire support, in sustaining the weight of the column of blood above them, and still more in an active sense, when, in contracting, the muscles swell and press against their sides, and thus assist in forcing onwards their contents. But these superficial veins are without this important help. Their sides are supported, on one hand, by the yielding layer of the fascia and muscles, and, on the other, by the integument. When, therefore, any impediment presents itself to the free transmission of the blood through the femoral, popliteal, or iliac veins, or even by the mere weight of the ascending column of blood, in persons who stand much, it is the superficial veins that suffer most, and a perma nently dilated state is the frequent result.
The pathology of varicose veins has not re ceived the attention which it deserves, and hence the conflicting opinions as to the precise nature of their origin ; we must even now con fess with Delpech that the nature and causes of the disease are unknown. It is quite clear that that state of disease of the veins commonly termed varicose comprehends more than one pathological condition, and probably has more than one mode of origin. Every instance of an enlarged vein cannot be considered as a varix, unless we confound under the same denomination a condition of the vessel natural and healthy except in regard to its size, neither originating nor terminating in a morbid condi tion, with every variety and degree of disease accompanied with enlarged capacity of the vein.
We have seen the veins of the abdomen en larged so as to fulfil the office of the vena cava inferior, which was obliterated. But there was not the slightest mark of disease in these super ficial vessels. The uterine veins, also, in preg nancy become enlarged in a similar manner, thus answering to the call for the increased circulation of blood in the uterus. This state of the vessels has been aptly termed hyper trophy, and the term varix has been restricted to permanently dilated states of the veins, at tended with the accumulation of dark blood, which more or less generally becomes coagu lated and adherent to the parietes ofthe vessels. Of this latter species Andral enumerates six varieties : 1st, simple dilatation without any other change, such dilatation affecting either their whole length, or occurring at intervals ; 2d, dilatation, either uniform or at intervals with a thinned state of the veins at the dilated points; 3d, uniform dilatation with thickening the venous coats ; 4th, dilatation at inter s with thickening of the dilated points ; 5th, atation, with the addition of septa within the n, whereby the cavity is divided into little Is in which the blood lodges and coagulates ; , a similar disposition combined with per tions in the parietes of the veins, which municate with the surrounding cellular .ue in a more or less diseased state by nume s small apertures. From repeated observa ion of its practical importance we should be dined to add to this list one other variety, iz. when the varicose state had extended into, r existed distinctly in, the capillaries of the in. We believe that in those troublesome leers known as varicose we shall frequently, not generally, find this state of the minister eins and capillaries, and we are more inclined attribute the pain and the obstinate character these ulcers to the pathological condition now mentioned than to the mere vicinity of an en larged vein as it passes through the superficial fascia. The causes of the diseased state in question have been variously stated, nor do opinions yet agree upon it, some attributing it to mechanical influence, and others supposing a morbid tendency. Both these causes pro bably act in different instances, or even co operate in the same case; we shall now only mention in illustration of the effect produce able by the mechanical influence of too much standing, that it is not necessary to suppose that the valves are either destroyed or even materially injured in structure to nullify their agency in supporting the column of blood above them, since ever so small a communi cation between the two columns, the upper and the under, is sufficient to destroy all the beneficial agency of the valves as supporters of the gravitating fluid in the veins. Therefore a dilatation of the vein merely enough to draw the opposed edges of the valve ever so little apart, or even a thickening of the valves pre venting the accurate coaptation of their edges, will be sufficient to prevent their power of support to the superincumbent column, and as far through the vein as this defective state of the valves may exist, so fist will the gravi tating column of blood be virtually unbroken and entire, and in the same proportion will the tendency to the varicose state be increased. This reasoning will explain many, probably the majority of cases where the morbid dila tation having once begun goes on to increase rapidly by the continued operation of this ex citing cause. That there are other causes capable of producing this state of the veins cannot be disputed ; indeed the occurrence of it in parts not likely to be affected by the up right position, and even in several different parts of the body of the same subject, skews that there is occasionally a morbid tendency in the venous system to this particular state, which acts independently of any mechanical cause; but we believe that this predisposing cause is not necessary to the production of the disease, and that the morbid tendency, when it is met with, should be regarded rather as the exception than as the rule.