The symptoms of aneurism vary according to its position. If it is not within the chest or belly, but in the neck or limbs, it appears as a tumour. The hand placed over it detects a pulsation in time with the beat of the heart. Any tumour placed over an artery would com municate the pulsation of the artery to the hand ; but a tumour apart from the artery might be pushed or lifted from the artery, when the pulsation would cease. This cannot be done with an aneurism. The swelling is from the commencement a soft one. Sometimes uniform and regular pressure will succeed in emptying the sac, and as soon as the hand is removed the blood fills it up again. If the artery be com pressed between the tumour and the heart the swelling becomes relaxed. Severe pain is occa sioned by pressure on nerves; veins may be ob structed, leading to dropsy ; and the constant pressure will even cause eating away of a bone. Of aneurisms in the limbs the most frequent is that situated on the artery in the popliteal space, the space between the hamstring muscles behind the knee. Next comes the femoral ar tery in the groin. Aneurism of the carotid and subclavian arteries (see p. 306) are not uncom mon. Commoner than all these, however, is aneurism of the aorta. Occurring as it does within a cavity of the body it is not so easy to recognize. Thus aneurisms occur in the chest connected with the aorta in the immediate neigh bourbood of the heart, or connected with the arch of the aorta, or with one of the large vessels springing from it, or with some part of the aorta as it descends through the chest towards the belly. These are called thoracic aneu risms. Aneurisms also occur on the aorta in its course through the cavity of the belly, or con nected with one of its large branches. These are abdominal aneurisms.
Now aneurisms in the chest or belly may attain such a size and bulge so much forwards that they are readily recognized as pulsating tumours. Thus a chest aneurism from the arch may bulge forwards, pressing on ribs and breast - bone, and may, by its pressure, eat through the ribs and breast-bone and appear as a regularly heaving mass, perhaps pushing its way up into the root of the neck, and threaten ing to burst through the skin. But, on the other hand, they may not project in this way, because of their situation, and there may be no visible external sign of their presence. In such cases the symptoms of their presence are due to the pressure they, are exerting on surrounding parts. Thus constant aching and shooting pain is likely to be the result of involving nerves. One of the
nerves of the windpipe may be involved and loss of voice result. Pressure ou the windpipe affect ing breathing and producing spasmodic cough, pressure on the gullet causing difficulty of swallowing, pressure on veins leading to con gestion and dropsy of some part of the body according to the vein that is obstructed, and so on, are some of the symptoms that may be pro duced by the aneurism. Aneurism of the arch of the aorta may also affect arteries in its neigh bourhood. Thus the artery going to one arm may be obstructed, and the pulse of that arm be absent or very feeble.
Thus whether the aneurism be external or internal it will require skill and experience to determine its true nature.
Treatment. — The treatment of external aneurism (aneurism not within a cavity of the body) is more simple than that of the internal variety. It naturally requires a surgeon, but various methods may be adopted. One method is to compress the artery nearer the heart than the aneurism, so as to delay the flow of blood and provoke the formation of a clot ; another is to tie the artery. The flow of blood is finally stopped in it, but gradually its branches above the tied part enlarge and carry on the circula tion. Till that is accomplished, great care is requisite to keep the limb warm by wrapping in cotton -wool, &c., lest mortification set in before the circulation is properly restored. It has been mentioned that sudden violent strain may produce aneurism, and the person often feels as if something had given way. If after such an experience a person finds a heaving tumour forming in the course of one of the arteries of the limbs, he ought to go to bed, and avoid interfering with the tumour, till surgical aid is obtained. In the event of an aneurism bursting, the main blood - vessel of the limb should be compressed as described under ACCIDENTS and EMERGENCIES.
The treatment of internal aneurism cannot be conducted on such lines. The patient is kept quiet in bed, and is allowed limited diet, in the hope that the formation of a firm clot in the sac will thus be aided. Some drugs, and especially iodide of potassium, are supposed to aid this result, and opium is used to relieve pain. Where the aneurism has projected from the chest wall, needles connected with galvanic batteries have been introduced into the sac, and the current passed for a few minutes at a time. This has been done for the purpose of aiding in coagulation of the blood in the sac, and has been successful in some cases.