the axilla, the collateral circulation will be weakly maintained, in
consequence of the small number of anastomosing branches arising from it
above and below the seat of the ligature. The two circumflex humeri
alone send down branches to inosculate with the small muscular offsets
from the middle of the brachial artery. When tied in the middle of the
arm between the origins of the superior and inferior profunda arteries,
the collateral circulation will depend chiefly upon the anastomosis of
the former vessel with the recurrent branch of the radial, and of
muscular branches with each other. When the ligature is applied to the
lower third of the vessel, the collateral circulation will be
comparatively free through the anastomoses of the two profundi and
anastomotic branches with the radial, interosseous, and ulnar recurrent
branches. If the artery happen to divide in the upper part of the arm
into either of the branches of the forearm, or into all three, a
ligature applied to any one of them will, of course, be insufficient to
arrest the direct circulation through the forearm, if this be the object
in view.
XVII.--The radial artery. If this vessel be tied in any part of its
course, the collateral circulation will depend principally upon the free
communications between it and the ulnar, through the medium of the
superficial and deep palmar arches and those of the branches derived
from both vessels, and from the two interossei distributed to the
fingers and back of the hand.
XVIII.--The ulnar artery. When this vessel is tied, the collateral
circulation will depend upon the anastomosis of the palmar arches, as in
the case last mentioned. While the radial, ulnar, and interosseous
arteries spring from the same main vessel, and are continuous with each
other in the hand, they represent the condition of a circle of which,
when either side is tied, the blood will pass in a current of almost
equal strength towards the seat of the ligature from above and below--a
circumstance which renders it necessary to tie both ends of the vessel
in cases of wounds.
XIX.--The common iliac artery. When a ligature is applied to the middle
of this artery, the direct circulation becomes arrested in the lower
limb and side of the pelvis corresponding to the vessel operated on. The
collateral circulation will then be carried on by the anastomosis of the
following branches--viz., those of the lumbar, the internal mammary, and
the epigastric arteries of that side with each other, and with their
fellows in the anterior abdominal parietes; those of the middle and
lateral sacral; those of the superior with the middle and inferior
haemorrhoidal; those of the aortic and internal iliac uterine branches
in the female; and of the aortic and external iliac spermatic branches
in the male. The anastomoses of these arteries with their opposite
fellows along the median line, are much less frequent than those of the
arteries of the neck and head.
XX.--The external iliac artery. This vessel, when tied at its middle,
will have its collateral circulation carried on by the anastomoses of
the internal mammary with the epigastric; by those of the ilio-lumbar
with the circumflex ilii; those of the internal circumflex femoris, and
superior perforating arteries of the profunda femoris, with the
obturator, when this branch arises from the internal iliac; those of the
gluteal with the external circumflex; those of the latter with the
sciatic; and those of both obturators, with each other, when
arising--the one from the internal, the other from the external iliac.
Not unfrequently either the epigastric, obturator, ilio-lumbar, or
circumflex ilii, arises from the middle of the external iliac, in which
case the ligature should be placed above such branch.
XXI.--The common femoral artery. On considering the circles of
inosculation formed around the innominate bone between the branches
derived from the iliac arteries near the sacro-iliac junction, and those
emanating from the common femoral, above and below Poupart's ligament,
it will at once appear that, in respect to the lower limb, the
collateral circulation will occur more freely if the ligature be applied
to the main vessel (external iliac) than if to the common femoral below
its branches.
XXII.--The superficial femoral artery. When a ligature is applied to
this vessel at the situation where it is overlapped by the sartorius
muscle, the collateral circulation will be maintained by the following
arteries:--the long descending branches of the external circumflex
beneath the rectus muscle, inosculate with the muscular branches of the
anastomotica magna springing from the lower third of the main vessel;
the three perforating branches of the profunda inosculate with the
latter vessel, with the sciatic, and with the articular and muscular
branches around the knee-joint.
XXIII.--The popliteal artery. When any circumstance renders it necessary
to tie this vessel in preference to the femoral, the ligature should be
placed above its upper pair of articular branches; for by so doing a
freer collateral circulation will take place in reference to the leg.
The ligature in this situation will lie between the anastomotic and
articular arteries, which freely communicate with each other.
XXIV.--The anterior and posterior tibial and peronoeal arteries. As
these vessels correspond to the arteries of the forearm, the
observations which apply to the one set apply also to the other.
[Footnote]
[Footnote: For a complete history of the general vascular system, see
The Anatomy of the Arteries of the Human Body, by Richard Quain, F.R.S.,
&c., in which work, besides the results of the author's own great
experience and original observations, will be found those of Haller's,
Scarpa's, Tiedemann's, &c., systematically arranged with a view to
operative surgery.]
THE END.