Symptoms of
pressure on the structures in the neck, similar to those produced by
aortic aneurysm, occur. The pulses in the right upper extremity and in
the right carotid and its branches are diminished and delayed. Pressure
on the right brachial plexus causes shooting pain down the arm and
muscular paresis on that side. Vaso-motor disturbances and contraction
of the pupil on the right side may result from pressure on the
sympathetic. Death may take place from rupture, or from pressure on the
air-passage.

[Illustration: FIG. 75.--Innominate Aneurysm in a woman, aet. 47, eight
months after treatment by Moore-Corradi method (cf. Fig. 73).]

The available methods of treatment are ligation of the right common
carotid and third part of the right subclavian (Wardrop's operation), of
which a number of successful cases have been recorded. Those most
suitable for ligation are cases in which the aneurysm is circumscribed
and globular (Sheen). If ligation is found to be impracticable, the
Moore-Corradi method or Macewen's needling may be tried.

#Carotid Aneurysms.#--Aneurysm of the _common carotid_ is more frequent
on the right than on the left side, and is usually situated either at
the root of the neck or near the bifurcation. It is the aneurysm most
frequently met with in women. From its position the swelling is liable
to press on the vagus, recurrent and sympathetic nerves, on the
air-passage, and on the oesophagus, giving rise to symptoms referable to
such pressure. There may be cerebral symptoms from interference with the
blood supply of the brain.

Aneurysm near the origin has to be diagnosed from subclavian,
innominate, and aortic aneurysm, and from other swellings--solid or
fluid--met with in the neck. It is often difficult to determine with
precision the trunk from which an aneurysm at the root of the neck
originates, and not infrequently more than one vessel shares in the
dilatation. A careful consideration of the position in which the
swelling first appeared, of the direction in which it has progressed, of
its pressure effects, and of the condition of the pulses beyond, may
help in distinguishing between aortic, innominate, carotid, and
subclavian aneurysms. Skiagraphy is also of assistance in recognising
the vessel involved.

Tumours of the thyreoid, enlarged lymph glands, and fatty and
sarcomatous tumours can usually be distinguished from aneurysm by the
history of the swelling and by physical examination. Cys