the sac, or of its
two branches where it bifurcates (Brasdor, 1760, and Wardrop, 1825), may
arrest or only diminish the flow of blood through the sac. It is less
successful than the proximal ligature, and is therefore restricted to
aneurysms so situated as not to be amenable to other methods; for
example, in aneurysm of the common carotid near its origin, the artery
may be ligated near its bifurcation, or in aneurysm of the innominate
artery, the carotid and subclavian arteries are tied at the seat of
election.

_Compression._--Digital compression of the feeding artery has been given
up except as a preparation for operations on the sac with a view to
favouring the development of a collateral circulation.

_Macewen's acupuncture or "needling"_ consists in passing one or more
fine, highly tempered steel needles through the tissues overlying the
aneurysm, and through its outer wall. The needles are made to touch the
opposite wall of the sac, and the pulsation of the aneurysm imparts a
movement to them which causes them to scarify the inner surface of the
sac. White thrombus forms on the rough surface produced, and leads to
further coagulation. The needles may be left in position for some hours,
being shifted from time to time, the projecting ends being surrounded
with sterile gauze.

The _Moore-Corradi method_ consists in introducing through the wall of
the aneurysm a hollow insulated needle, through the lumen of which from
10 to 20 feet of highly drawn silver or other wire is passed into the
sac, where it coils up into an open meshwork (Fig. 73). The positive
pole of a galvanic battery is attached to the wire, and the negative
pole placed over the patient's back. A current, varying in strength from
20 to 70 milliamperes, is allowed to flow for about an hour. The hollow
needle is then withdrawn, but the wire is left _in situ_. The results
are somewhat similar to those obtained by needling, but the clot formed
on the large coil of wire is more extensive.

[Illustration: FIG. 73.--Radiogram of Innominate Aneurysm after
treatment by the Moore-Corradi method. Two feet of finely drawn silver
wire were introduced. The patient, a woman, aet. 47, lived for ten months
after operation, free from pain (cf. Fig. 75).]

Colt's method of wiring has been mainly used in the treatment of
abdominal aneurysm; gilt wire in the form of a wisp is introduced
through the cannula and expands into an umbrella shape.

_Subcutaneous Injection