In those cases (once much more frequent than at present) where an aneurism has formed after a wound of the brachial at the bend of the arm in venesection, the aneurism may be either circumscribed or diffuse.
If circumscribed, it is advised by some surgeons, specially by the late Professor Colles of Dublin, that the brachial should be tied immediately above the tumour. In most cases of circumscribed, and in all such cases of diffuse aneurism, the preferable operation is boldly to lay open the tumour, turn out all the clots, seek for the wound in the artery, and tie the vessel above and below. A tourniquet above, or, better still, a trustworthy assistant, prevents all fear of hæmorrhage, and such a radical operation exposes the limb to far less chance of gangrene than do any attempts at removing or lessening the tumour by pressure (as recommended by Cusack, Tyrrell, Harrison), and is much more certain than a mere ligature above.[21]
Ligature of Vessels in Fore-arm.—Here, as also we found is the case in the leg, it is almost useless to go on giving exact directions as to the method of throwing a ligature round the vessels in all possible situations.
For below the elbow spontaneous aneurism is almost unknown, and even traumatic aneurisms are extremely rare. It is therefore for hæmorrhage only that the vessels are likely to require ligature, and it is a rule in surgery that to enlarge the wound and to apply a ligature above and below the bleeding point is better practice than to apply a ligature at a distance.
In the case of wounds of the palmar arch, it is extremely difficult, and very apt to injure the future usefulness of the hand, thus to seek for the bleeding point under the palmar fascia, and for these, ligatures of radial and ulnar have occasionally been practised. However, as even this has proved ineffectual, and the interosseous has proved sufficient to continue the bleeding, ligature of the brachial at once is preferable to ligature of so many branches in the fore-arm.
The use of graduated compresses, carefully applied, combined with flexion of the elbow over a bandage, will generally prove sufficient to check such hæmorrhage from the palm, without having recourse to either of the above more severe measures.
Note.—As in the lower limb at page 24, and for the same reasons, I here insert a brief account of the methods of tying the ulnar and radial arteries.
1. Ligature of Ulnar.—Only admissible in the lower half of its course. Operation.—Use the tendon of the flexor carpi ulnaris as a guide, and make an incision along its radial edge, at least two inches in length; expose the deep fascia of the arm and then cautiously divide it; then bending the hand, the flexor carpi ulnaris is relaxed, and the artery is found lying pretty deeply between it and the flexor sublimis digitorum. The ulnar nerve lies at its ulnar side, and the venæ comites accompany the artery. In a tolerably muscular arm, the incision will have to be about an inch inside of the ulnar border of the limb.
2. Radial.—This artery lies more superficial than the preceding, and may be tied at any part of its course.
A. Operation in upper part of fore-arm. Here the artery lies in the interval between the supinator longus and the pronator radii teres. In a muscular arm, the edge of the former muscle is the best guide; in a fat one, the incision may be made in a line extending from the centre of the bend of the arm to the inner edge of the styloid process of the radius. The deep fascia must be exposed and opened, and the muscles relaxed and held aside. The radial nerve lies on the radial side of the vessel.