The object of the operation is in the first instance to reach the outer edge of the anterior scalenus muscle: this lies immediately below the outer edge of the clavicular portion of the sterno-cleido-mastoideus, and the division of a portion of this part of the muscle will greatly facilitate the subsequent steps of the operation, although it may be done without it. The artery will be found crossing over the first rib at the very edge of the attachment of the scalenus anticus to it; but a quantity of cellular substance and fascia intervenes, which must be torn through before it can be exposed. This should be done with a blunt, round-pointed knife, in a line parallel with the first incision, but more immediately over the outer edge of the scalenus muscle. The omo-hyoideus muscle passing obliquely across the root of the neck will be in this manner exposed, which should be clearly done, because it narrows the space in which the operation is to be performed to a small triangle; the outside and apex of which is formed by this muscle, the inside by the scalenus anticus, the base by the rib, above it the subclavian vein, and above it again, but under the clavicle, the supra-scapular artery and vein. The blunt knife, working in the triangular space, will first expose one or more of the nerves of the axillary plexus, which again diminishes the space; more inwardly the scalenus anticus will be felt, and should be seen by tearing through the thin fascia which lies behind the omo-hyoideus, and is connected with it. The point of the finger, assisted if necessary by the blunt knife, should be passed along the edge of the muscle until it rests on the first rib, and at the angle formed between the muscle and the rib the artery will be found and known by its pulsation. The operator should detach the artery in a slight degree from its connections, with the nail of the forefinger, and the aneurismal needle should be passed in preference from below upward, by which the pleura will be avoided. After the ligature has been passed under the artery, the vessel should be pressed upon with the finger, while the ligature is firmly held in the other hand, by which the circulation through the artery will be stopped. The pulsation in the tumor and at the wrist should cease, when the ligature may be tied with a double knot; for doing this, one or two steel probes, having a ring at the end, placed at a right angle with the shaft, will afford great assistance.
In some instances, particularly in short-necked persons, the omo-hyoideus lies close to the clavicle, and requires to be drawn upward and outward from it. In others, the lowest nerve of the axillary plexus lies over the artery, and may be mistaken for it. When the veins coming from the neck are large and numerous, great care should be taken to avoid injuring them, as they frequently cause not only much hemorrhage, but great delay. Great care must also be taken in all these operations to prevent the ingress of air into any of the veins which may by accident be opened, as its admission in quantity has occasioned sudden death, although the entrance of a few bubbles may not be so dangerous as has been supposed.
236. When the axillary artery is to be tied for a wound caused by a sharp-pointed or other instrument which has been forced through the pectoral muscle or under it from the axilla, the patient is to be firmly supported or placed in the horizontal position, the arm to be slightly separated from the body, and an incision made in the course of the axillary artery, through the integuments, superficial fascia, and the great pectoral muscle—in fact, through the anterior fold of the armpit. The length of the incision will depend on the part at which the artery is to be secured. The parts divided being separated, the pectoralis minor will be seen crossing to the coracoid process at the upper part of the wound, and the artery may be felt below it, inclosed in its cellular sheath, with the nerves of the arm and its venæ comites. All other modes of attempting this operation are unworthy consideration, and ought to be discarded as dangerous and insufficient.
At the lower edge of the pectoralis minor, the artery is crossed by the outer of the venæ comites, which passes between the external cutaneous and the external origin of the median nerve, at the spot where they separate from the plexus. The artery may be tied below this separation, or the nerves and vein may be drawn to the outside, and the artery tied above the union of the external with the internal root of the median nerve as high as the origin of the arteria thoracica acromialis, the pectoralis minor being either raised and pushed upward, or divided if necessary. The internal root of the median nerve is in connection with the internal cutaneous and ulnar nerves; the larger of the venæ comites is to the inside and behind, but as it ascends it receives its fellow, and with the cephalic vein forms in front of the artery the subclavian vein.
237. The brachial artery can be traced by its pulsation from the lower edge of the teres major muscle to below the bend of the arm, where it is covered by the pronator radii teres muscle. At first it is on the ulnar side of the humerus, resting on the triceps, and slightly overlapped by the coraco-brachialis and biceps muscles. In the middle of the arm it rests on the tendon of the coraco-brachialis, is close to the bone, and lies under the lower edge of the biceps; in which situation it may always be compressed by bending the forearm, so as to cause the belly of the biceps to enlarge, when pressure made immediately below it will arrest the circulation in the brachial artery. It then crosses toward the anterior part of the arm, and rests on the brachialis anticus muscle until it passes the bend of the elbow. It is accompanied by two veins, which are connected with it by a loose cellular membrane forming a sheath. The external cutaneous and median nerves lie a little to the outside of the artery in the upper third of the arm. In the middle third the median nerve lies generally in front of, but sometimes between the artery and the bone, and is on the inside at the inferior part. The internal cutaneous nerve runs parallel with but superficial to the artery, the ulnar nerve nearer but posterior to it. When a ligature is to be placed on the brachial artery in the upper part of its course, the incision should be made about three inches in length, directly on the line of the pulsating vessel, by which all mistakes will be avoided. The integuments should be divided carefully, that the internal cutaneous nerve may not be injured; the fascia is then to be cut through and the forearm bent, when the vessels and nerves will be relaxed. The artery is to be separated from its veins, one on each side; and it must be recollected that the external cutaneous and median nerves are to the radial side of the artery, the internal cutaneous and the ulnar nerves to the ulnar side of it. In the middle of the arm the median nerve lies immediately over the artery, except in those cases where it passes behind it; when it lies in front it may be mistaken for the artery, from the pulsation being communicated to it. The incision should be to the same extent of three inches, directly in the course of the artery, and the ligature should be passed from the ulnar to the radial side of the vessel, in order to avoid the possibility of including either the internal cutaneous or the ulnar nerve, and for the purpose of excluding both the veins.
238. The brachial artery, a little below the bend of the arm, divides into the radial and ulnar arteries—the radial being the continuation of the brachial in direction, the ulnar in size. The brachial artery, at the bend of the arm, is cushioned on the brachialis internus muscle, having the tendon of the biceps on the outside, the median nerve on its inside, which is at first continued on the same side of the artery, which now takes the name of ulnar. This vessel inclines toward the ulna for about an inch, and then passes between the two origins of the pronator radii teres muscle; the median nerve crosses it at this part to get into the middle of the arm, and is then separated from it by the ulnar origin of the muscle. The artery continues its course, inclining outwardly, under the pronator radii teres, the flexor carpi radialis, the palmaris longus, and the flexor sublimis muscles, lying on the flexor profundus. On clearing the ulnar edge of the flexor sublimis, it is covered by the flexor carpi ulnaris, the course of the artery having been obliquely under these muscles to the extent of two inches. To tie it in any part of this course, they must be more or less divided, and the only difficulty or danger arises from the median nerve, which lies deeper under the radial origin of the pronator teres. But the whole of the muscular fibers may be divided, without injuring the nerve, by successive and careful incisions through them until the artery and nerve are exposed, and a ligature may then be applied above and below the wound in the vessel. It may be supposed, by way of elucidation, that a man has received a wound from a sword through the flexor muscles, which injures also the ulnar artery, as may be presumed from its situation and the continued and impetuous flow of blood. It may be further supposed that this wound is in a slanting direction from the ulna toward the radius. The surgeon, if he thinks he can calculate the point at which the artery is injured, should cut down upon it in the direction of the fibers of the intervening muscles, and even through them until he reaches the artery; but if he has erred in his calculation, he should introduce a probe into the wound, and, after having ascertained the line it has taken, he should cut, if necessary, across the muscular fibers in that direction until he exposes the bleeding artery; if he be careful not to divide the median nerve, no inconvenience will arise from the operation. (Aph. 184, page 192.)
239. If the ulnar artery be wounded near its origin, through the radial side of the pronator teres muscle, an incision should be made through the integuments and the aponeurosis of the biceps muscle; the pronator muscle being then exposed, it is to be drawn inward and downward, or toward the ulna, and the dissection continued until the median nerve is brought into view. The probe introduced through the original wound will lead to the artery, the pulsation of which will be felt and the bleeding seen. Where the nerve crosses the artery, the vessel will be found above or to the radial side of it, and to the ulnar side below. It may be tied above without dividing a muscular fiber; but at the part where the nerve crosses, and below it, some fibers of the pronator teres must be divided, and in some cases the whole of them, before the artery can be properly secured by two ligatures; but this division is of little or no consequence, as the muscular fibers reunite without difficulty.
240. To tie the ulnar artery in the middle third of the arm, the surgeon should bend the wrist, and trace upward the tendon of the flexor carpi ulnaris as far as it can be felt. At the point where it becomes indistinct, an incision should be commenced and carried upward for the space of four inches; the fascia is then to be divided to the same extent, when the flexor carpi ulnaris may readily be traced upward by its tendon, which is on the radial side of it; this muscle may then be easily separated from the flexor sublimis, beneath the edge of which the artery will be found covered by the deep-seated fascia, having a vein on each side, and the ulnar nerve to the ulnar side of it. By this method of proceeding the artery will be readily exposed, which is not always the case by any other manner of operating, and it may be tied as high up as where it passes from under the flexors of the arm.
The ulnar artery may be easily tied near the wrist, where it is most superficial. Bend the wrist, and make the flexor carpi ulnaris act, when the tendon will be felt internal to the styloid process of the ulna; make an incision two inches and a half in extent along the radial edge of this tendon, dividing the fascia of the arm which covers it. The artery will be felt below the deep-seated fascia, and, on dividing it, will be seen with its venæ comites, the ulnar nerve being behind it; that nerve must be avoided, in the application of a ligature.
241. The radial artery may be secured by ligature with great ease in any part of its course to the wrist. At the upper third of the arm, the radial artery is covered by the approximation of the supinator radii longus and pronator radii teres muscles. To expose it at this part, a line may be drawn from the middle of the bend of the arm to the thumb, which will indicate its course; or the supinator radii longus being put into action, an incision is to be made from the bend of the arm obliquely outward along its ulnar edge to the extent of three inches, avoiding the median vein, but dividing the integuments and the fascia. The supinator muscle is then to be gently separated from the pronator radii teres by the handle of the knife, and the artery will be felt covered by the deep-seated fascia; on the division of which, it will be seen with its venæ comites lying on some adipose membrane, and on some branches of the musculo-spiral nerve, which separate it from the tendon of the biceps, and are to be carefully avoided. The musculo-spiral nerve itself lies nearer the radius, rendering it advisable to pass the aneurismal needle from that side.