Varicose aneurism.—When a vein and artery communicate with each other in a manner similar to that already described, excepting that an aneurismal sac formed of condensed cellular tissue and containing some coagulated blood is interposed between their orifices, the disease is termed a varicose aneurism. As this disease is generally the result of some accident in bleed ing, as it occupies the same situation at the bend of the arm, and as the sac in that case never attains to any considerable size, it is difficult and frequently impossible to distinguish during life between the two affections : nor is the diagnosis of much importance, for as the patho logical changes in the artery and vein, and the phenomena produced by them, are exactly the same, so will be the rationale of the treatment.
Some few years since, a patient was admitted into the Charitable Infirmary with a popliteal aneurism of the size of a child's head, and with all- the veins of the limb, particularly of the thigh, enormously distended so as to appear like ropes twisted and knotted under the in teguments. In every one of these veins the peculiar thrill and sound of aneurismal varix could be distinctly perceived. The account he gave of himself was this : he had a pulsating tumour in the ham for fourteen years previ ously, which gradually increased to its present size, until the veins began to swell, when the large tumour became stationary. He expe rienced but little inconvenience, and said he was able to walk eleven or twelve miles a day. He was frequently permitted to leave the hos pital, and exhibited himself to several profes sional men for money. As he refused to sub mit to any treatment, and indeed no operation held out a prospect of much benefit, he was soon discharged. This man (I believe) still lives, and as be resides in a distant part of the country, perhaps the true pathological nature of a case so very interesting may never be ascertained. Could it have been that this was originally a case of popliteal aneurism that had burst into the popliteal vein ? The position of this vein, and its very intimate connexion with the artery, causq it to appear to be a part of the sac of every popliteal aneurism, and it is not difficult to conceive that the tumour might have given way in this particular situation, and a communication been thus established between the artery and vein through the medium of the aneurismal sac.
It may not be unimportant to observe, that rare as these latter forms of disease are acknow ledged to be, they are still more so in reality than is generally imagined. It often happens that a congeries of knotted and contorted veins forms a tumour strongly resembling the aneu rismal varix in its external characters, and im parting similar sensations of thrill and sound. If one of these happens to occupy a situation favourable to the production of aneurismal varix, it might easily occasion a mistake, and perhaps it would be very difficult to point out a satisfactory diagnostic. I have seen two of these tumours dissected, which during the lives of the patients were supposed to have been aneurismal varices, in neither of which could the slightest commu nication with any neighbouring artery be dis covered.
Aneurism by anastomosis.—The disease which was so named by John Bell, and by him first placed in the class of aneurismal tumours, has no title to such a position, unless that it forms a reservoir of blood, and occasionally exhibits the phenomenon of pulsation. But it mate rially differs in that the blood contained within it is fluid, is not withdrawn from the circulation, and therefore does not coagulate. The circum stances, however, of these tumours being in creased or diminished in size by those influ ences which excite or depress the activity of the circulation, and of the leading trunks of the vessels supplying them having, however erroneously, been made the subjects of opera tion for their cure, serve to connect them in some respects with the pathology of arteries, and justify a passing notice of the subject here. This
kind of tumour has also been called the nvus maternus or mother mark, because it so often appears from birth or at a very early age, and its shape, colour, size, or situation is explained by the mother on the supposition of some sub having been thrown at her, or from other causes of affright. It may, however, appear for the first time in more advanced life, in the form of a speck or pimple, which gradually enlarges until it constitutes a disease of a most important and sometimes dangerous nature.
The external characters of aneurism by anas tomosis are somewhat varied, and have admitted of its classification under three forms apparently distinct from each other : 1. Where the mark or stain is merely cutaneous, does not increase in size, and is never pulsatile. These marks may be of different colours, sometimes red, sometimes of a brassy yellow, or perhaps brown ; and as they occasion no inconvenience beyond the unsightliness of their size and situation, they can scarcely be considered as diseases. Indeed, if the common mole be admitted un der this class of naevi, in many instances it seems to constitute a beauty rather than a defect. 2. Where the disease is situated in both the skin and sub-cutaneous cellular tissue. It appears as a patch, slightly elevated, of a red or purple colour, being generally of a brighter hue on the face or breast, and darker on those parts usually kept covered. The colour of the noevus also seems to depend on the quality of the blood with which it is altogether or prin cipally supplied, as sometimes tumours are met with which might be termed venous aneurisms of this description, consisting evidently of veins indurated, knotted, and contorted on each other, increasing gradually, and never pul satile; these frequently occur in different parts of the body of the same individuaband are always attended more or less with pain. The arterial nwvus is, however, most intimately connected with the present subject. It sometimes pre sents an appearance as if irregularly granulated; more frequently is it smooth and velvety. The deep stain possesses a sharp and circumscribed edge, yet a net-work of minute vessels may be seen like an areola around it, conveying blood to nourish the tumour, and therefore forming an important part of the diseased structure. The tumour is increased in size and intensity of colour by every thing that accelerates the circu lation—by exercise, intemperance, paroxysms of passion, and even by an elevation of tem perature, and hence the supposed marks of currants and other fruits are said to grow red and ripen at the proper season. Its feel is doughy, and communicates a sensation as if it contained a jelly. It sinks, and is diminished by pressure on its surface, but immediately the pressure is removed it recovers its former level. It may be stationary for years, but the contrary is generally observed ; its growth, however, is always irregular, being more rapid at one period than another. 3. The distinguishing charac teristic of the third form of nanrus is its pulsa tility. It beats synchronously with the heart and arteries. When wounded, blood of a bright red colour flows from it, often in such abundance as to occasion syncope or even more dangerous consequences. As it grows larger, the skin gradually becomes thin ; it bursts and bleeds ; masses of coagula lie upon its surface, putrefying and occasioning the most unsightly appearance and most offensive odour. This is a condition that cannot endure long, the patient soon becomes irritable and weak, and falls a victim to that irregular, ill-formed hectic which is seen in every disease accompanied by extensive haemorrhages. It is manifest that the distinctions between these latter forms of nvevi are merely artificial ; the second can be made to pulsate and to increase by heat or intern perance;the third can often be restrained by cold, by abstinence, and other means that debilitate the circulation.