Page:Muscles and Regions of the Neck.djvu/26

24 rising in the vicinity of the sterno-clavicular articulation, have been mistaken for aneurisms of the innominata, on the one side, or of the carotid or subclavian on the other, according as they have, in their growth, deviated right or left from the median line. Burns records a case, in which an aneurism so originating from the aorta, was even falsely attributed to the right subclavian: it bulged first on the acromial side of the sterno-mastoid muscle, "a point, where no one would expect a tumour to present, which had worked its way from within the chest." This is an extreme and rare instance; but not so are the misapprehensions, previously alluded to: it is certain, and matter of frequent experience, that aneurisms of the arch, where they escape from the resisting stricture of the sternum and clavicles, project so abruptly, as to have the appearance of belonging to the artery, over which their fundus is situated. They frequently have (as in the case which Burns quotes from Sir Astley Cooper) a Florence-flask-like form, the neck of which may be narrow, and the fundus high in the neck. In several such cases the deception has been so complete, as to suggest to the surgeon the propriety of tying the common carotid below its supposed aneurism: but no instance is on record, as I believe, of the adoption of so calamitous a proceeding. It is, indeed, true and almost self-evident that an aneurismal swelling, formed at the root of the carotid, will commonly first be perceived in the small interval between the heads of the sterno-mastoid, and, in its further growth, may displace these, or cause their absorption:—that one connected with the arteria innominata is likely to project nearer to the trachea, and on the inner side of the sterno-mastoid:—that one originating from the subclavian will usually rise on the outer side of the same muscle; and that the force of the pulse is generally diminished in the branches of a trunk affected with aneurism: yet, while such facts may have their weight, as excluding certain tumours from the respective categories of subclavian, carotid, or innominata aneurism, and as so assisting the negative diagnosis of these diseases,—it admits of no doubt that they are insufficient to establish grounds for positive recognition. The aortic aneurism may imitate every circumstance of position in the neck, which has been mentioned; and can hardly fail by its abnormal pressure to affect the circulation through the contiguous artery, and to weaken the pulse of its branches. To other criteria, than the mere symptom of external prominence, the cautious surgeon will look for a safe diagnosis of swellings in the root of the neck. The minutest inquiry into the history of the patient during the period, which preceded any outward projection of the tumour, and into the actual state of his thoracic organs and of their functions (with notice of every pain, palpitation, or dyspnœa),—an observation of any existing impediment to the return of blood, as evidenced by venous congestion, —and complete and careful stethoscopy, are all requisite to that study of the particular case, which alone can justify an opinion.

2. An important subject for mention, in regard to the surgical anatomy of the neck, is the provision for collateral circulation, when the main trunks are obliterated. Mr. Burns, in discussing the question of tying the arteria innominata, speaks of these natural resources in the spirit of confidence, which has been familiar to English surgery, since the time of its profound lawgiver, John Hunter: "We entertained no dread of the circulation being supported in the right arm; nay, we reduced it to a demonstration. On the dead subject, I tied the arteria innominata with two ligatures, and cut across the vessel in the space between them, without hurting any of the surrounding vessels. Afterwards, even coarse injection impelled into the aorta, passed freely by the anastomosing vessels into the arteries of the right arm, filling them and all the vessels of the head completely." The fluid passed (as the blood would, under similar circumstances, pass in the living subject) from the carotid of the left side to that of the right, through the mesial inosculations of the thyroid, lingual, facial, temporal, occipital, and (not least) cerebral arteries: from the left subclavian, in like manner, chiefly through the thyroid and vertebral branches; and thus a regurgitant stream would flow into the main vessels, up to the very site of ligature. Partly through the continued trunk of the tied vessel, so reinforced by its fellow, and partly by secondary communications (as of the occipital with the cervicalis profunda, of the facial with the internal maxillary, of the pharyngeal and palatine arteries) the blood is distributed in its legitimate destination. If the subclavian alone be obliterated at its commencement, the inferior thyroid and vertebral (communicating with their fellows, but still more largely with the carotid of the same side) helped by the muscular branches of the occipital, will convey the derived current. If the ligature have been applied beyond the scaleni, the transverse branches of the thyroid axis, by their free inosculations with the articular branches of the axillary, and with its subsca-