Part 34 (2/2)

[Footnote: The main artery (Plate 47) has been exposed in the iliac and femoral regions with the object of showing the relation which its parts bear to each other and to the whole; all the other dissections have been made upon the same plan, the practical tendency of which will be ill.u.s.trated when considering the subject of arterial anastomosis.]

The external iliac part of the artery, G I, when requiring to be tied, may be reached in the following way: an incision, commencing above the anterior iliac spine, B, is to be carried inwards parallel to, and above, Poupart's ligament, D, as far as the outer margin of the internal abdominal ring. This incision is the one best calculated for avoiding the epigastric artery, and for not disturbing the peritonaeum more than is necessary. The skin and the three abdominal muscles having been successively incised, the fibrous transversalis fascia is next to be carefully divided, so as to expose the peritonaeum. This membrane is then to be gently raised by the fingers, from off the iliacus and psoas muscles as far inwards as the margin of the true pelvis where the artery lies. On raising the peritonaeum the spermatic vessels will be found adhering to it. The iliac artery itself is liable to be displaced by adhering to the serous membrane, when this is being detached from the inner side of the psoas muscle. [Footnote] The artery having been divested of its serous covering as far up as a point midway between I G, the epigastric and internal iliac branches, the ligature is to be pa.s.sed around it in this place, as being equidistant from these two sources of disturbance. As the vein, K, lies close along the inner side of the artery, the point of the instrument should first be inserted between them, and pa.s.sed from within outwards, in order to avoid wounding the vein. If an aneurism affect the upper end of the external iliac artery, it is proposed to tie the common iliac; but this is an operation of so serious a nature, that it can in this respect be exceeded only by tying the aorta itself. The common iliac artery is so situated, that it can as easily be reached from the groin upwards as from the side of the abdomen inwards, and in both directions the peritonaeum would have to be disturbed to an equal extent.

[Footnote: The student, in operating upon the dead subject, is often puzzled to find that the iliac artery does not appear in its usual situation, unaware at the time that he has lifted the vessel in connexion with the peritonaeum. I have once seen a very distinguished surgeon, whilst performing this operation on the living body, at fault owing to the same cause.]

DESCRIPTION OF PLATE 47.

A. The aorta at its point of bifurcation.

B. The anterior superior iliac spine.

C. The symphysis pubis.

D. Poupart's ligament, immediately above which are seen the circ.u.mflex ilii and epigastric arteries, with the vas deferens and spermatic vessels.

E E*. The right and left iliac muscles covered by the peritonaeum; the external cutaneous nerve is seen through the membrane.

F. The vena cava.

G G*. The common iliac arteries giving off the internal iliac branches on the sacro-iliac symphyses; g g, the right and left ureters.

H H*. The right and left common iliac veins.

I I*. The right and left external iliac arteries, each is crossed by the circ.u.mflex ilii vein.

K K *. The right and left external iliac veins.

L. The urinary bladder covered by the peritonaeum.

M. The r.e.c.t.u.m intestinum.

N. The profundus branch of the femoral artery.

O. The femoral vein; 0, the saphena vein.

P. The anterior crural nerve.

Q. The sartorius muscle, cut.

S. The pectinaeus muscle.

T. The adductor longus muscle.

U. The gracilis muscle.

V. The tendinous sheath given off from the long adductor muscle, crossing the vessels, and becoming adherent to the vastus internus muscle.

W. The femoral artery. The letter is on the part where the vessel becomes first covered by the sartorius muscle.

<script>