If, according to Tillmann, the point of communication between the artery and vein be compressed, the pulsation in the dilated and tortuous vessels ceases, and they collapse.
The limb is generally wasted below the varix if the ease is one of long standing; it may also be oedematous, hard, and en larged.
In twenty-nine cases of aneurism of the ascending arch of the aorta opening into the vena cava analyzed by Pepper and Griffith, a thrill was observed in some cases; in others a continuous mur mur with systolic increase, with sudden development of cyanosis, oedema, and en gorgement of the veins of the upper part of the body.
Case of traumatic arterio-venous an eurism of the arch of the aorta and the innominate vein. The thrill was most distinct over the manubrium sterni, and could be followed down the internal jugular and left brachial veins and over the skull in the course of the sinuses. The autopsy showed an opening in the arch of the aorta between the points of origin of the carotid and the innominate arteries, which communicated directly with the left innominate vein: dilated at this point to the size of an orange. Long survival after the accident is worthy of notice. Colzi (Lo Speri mentale, Feb., '95).
Etiology. Both varieties are caused by traumatisms by which an artery and vein in juxtaposition are wounded simul taneously from a stab or in phlebotomy. Arterio-venous aneurisms were much more frequent when veneseetion was in vogue than they are now that this procedure is rarely resorted to.
A true aneurism may gradually ad here to a vein, and give rise to an arterio venous aneurism.
Case of spontaneous, probably con genital, arterio-venous aneurism of the arm and hand, caused by an abnormal communication between the common in terosseous artery and a deep branch of the cephalic vein. Ligature of the bra chial artery followed by gangrene of the forearm and hand; amputation; recov ery. Weidemann (Beitrilge zur klin. Chir., Sept. 15, '93).
Pathology. — Besides the features al ready noted is the fact that the wound between the vessels does not heal, so that at each pulsation a certain amount of blood is forced through from the artery into the vein. The latter pulsates strongly and becomes tortuous and di lated; the veins beyond the aneurismal varix on the limb are likewise dilated.
The artery is more or less dilated above, but much contracted below, the lesion.
aneurismal varix may, as already stated, cause no very serious disturbance, and is not, therefore, re garded as a dangerous condition. This is not the case, however, with varicose aneurism, as the intervening sac may at any moment become disorganized and give rise to a diffuse aneurism. The varicose veins may also become greatly enlarged, and be followed by oedema and perhaps gangrene.
Case of fourteen years' standing, caused by a punctured wound of the axilla. Arm normal, veins not dis tended, function perfect, but all over the arm the characteristic bruit could be heard; operation contra-indicated. Osier (Annals of Surgery, Jan.. '92).
Case of aneurismal varix of the left in ternal carotid artery and the cavernous sinus. It has remained unaltered for twenty-three years. C. E. Williamson (Brit. Jour, Oct. 13, '94).
Fourteen eases of arterio-venous anen rism of subelavian published. Case in which there was no syncope at the time of accident and seven months after de velopment of aneurism no functional trouble. Wedenkind (Deutsche med. Woch., No. 16, '95).
Treatment. — In the majority of cases aneurismal varix requires no treatment, or no more than the application of an elastic bandage to prevent its growth.
Where extension of the affection causes pain and disturbance in the cir culation, compression may be applied above and below and upon the tumor itself; should this not succeed, the artery and vein can be tied above and below the opening, and the aneurism removed. It is only when absolutely necessary that aneurismal varix of the femoral vessels or of the carotid and internal jugular should be submitted to operative pro c edures.
Unlike aneurismal varix, varicose an eurisms, as stated, present an element of danger: the intermediate sac, owing to its histological composition, tending to ulcerate at any moment and to give rise to a diffuse aneurism. Pressure is ob viously contra-indicated; it would cause enlargement of the already dilated veins and probably give rise to oedema and gangrene. The best treatment, especially when the aneurism is small, is to tie both vessels above and below the aneurism. and to remove the latter.