ompletely
lost. The arrest of the blood supply may result in gangrene. Sometimes
the pressure of the extravasated blood causes the skin to slough and,
later, give way, and fatal haemorrhage results.

The _treatment_ is carried out on the same lines as for a ruptured
artery (p. 261), it being remembered, however, that the artery is
diseased and does not lend itself to reconstructive procedures.

_Suppuration_ may occur in the vicinity of an aneurysm, and the aneurysm
may burst into the abscess which forms, so that when the latter points
the pus is mixed with broken-down blood-clot, and finally free
haemorrhage takes place. It has more than once happened that a surgeon
has incised such an abscess without having recognised its association
with aneurysm, with tragic results.

#Treatment.#--In treating an aneurysm, the indications are to imitate
Nature's method of cure by means of laminated clot.

_Constitutional treatment_ consists in taking measures to reduce the
arterial tension and to diminish the force of the heart's action. The
patient must be kept in bed. A dry and non-stimulating diet is
indicated, the quantity being gradually reduced till it is just
sufficient to maintain nutrition. Saline purges are employed to reduce
the vascular tension. The benefit derived from potassium iodide
administered in full doses, as first recommended by George W. Balfour,
probably depends on its depressing action on the heart and its
therapeutic benefit in syphilis. Pain or restlessness may call for the
use of opiates, of which heroin is the most efficient.

_Local Treatment._--When constitutional treatment fails, local measures
must be adopted, and many methods are available.

#Endo-aneurysmorrhaphy.#--The operation devised by Rudolf Matas in 1888
aims at closing the opening between the sac and its feeding artery, and
in addition, folding the wall of the sac in such a way as to leave no
vacant space. If there is marked disease of the vessel, Matas' operation
is not possible and recourse is then had to ligation of the artery just
above the sac.

_Extirpation of the Sac--The Old Operation._--The procedure which goes
by this name consists in exposing the aneurysm, incising the sac,
clearing out the clots, and ligating the artery above and below the sac.
This method is suitable to sacculated aneurysm of the limbs, so long as
they are circumscribed and free from complications. It has been
successfully practised also in aneurysm of t