The Surgical Dissection Of The Superficial Bloodvessels Etc Of The Inguino-femoral Region

Sources: Surgical Anatomy

Hernial protrusions are very liable to occur at the inguino-femoral

region; and this fact has led the surgeon to study the anatomical

relations of this part with more than ordinary care and patience. So

minutely has he dissected every structure proper to this locality, and

so closely has he investigated every possible condition of it as being

the seat of hernial, that the only novelty which now remains to be

sought for is that of a simplification of the facts, already known to be

far too much obscured by an unwieldy nomenclature, and a useless detail

of trifling evidence. And it would seem that nothing can more directly

tend to this simplification, than that of viewing the inguinal and

femoral regions, not separately, but as a relationary whole. For as both

regions are blended together by structures which are common to both, so

do the herniae which are described as being proper to either region,

occur in such close connexion as at times to render it very difficult to

distinguish between them.



The human species is, of all others, most subject to hernial in the

groin. The erect attitude of the human form, and the fact that many of

its more powerful muscular efforts are performed in this posture, cause

its more frequent liability to the accidents called abdominal herniae or

ruptures.



The viscera of the abdomen occupy this cavity completely, and indeed

they naturally, at all times, subject the abdominal parietes to a state

of constant pressure, as may be proved by their escape from the abdomen

in cases of large wounds of this region. In the erect posture of the

body this pressure is increased, for the viscera now gravitate and force

downwards and forwards against the abdominal parietes. In addition to

this gravitating force, another power impels the viscera from above

downwards--namely, that of the muscles of the trunk, and the principal

agent amongst these is the diaphragm. The lungs, again, expanding above

the diaphragm, add also to the gravitation of the abdominal contents,

and these, under the pressure thus accumulated, occasionally make an

exit for themselves at the groins, which are the weakest and most

depending parts of the abdomen.



Herniae are variously named in accordance with the following

circumstances--viz., the precise locality at which they occur--the size

and form of the tumour--the time of life at which they happen. Sexual

peculiarities do not serve to distinguish herniae, though it is true

that the inguinal form, at the part D F, occurs more commonly in the

male, whilst the crural form, at the opening E, happens more frequently

in the female.



The most common forms of herniae happen at those localities where the

abdominal walls are traversed by the bloodvessels on their way to the

outstanding organs, and where, in consequence, the walls of the abdomen

have become weakened. It also happens, that at these very situations the

visceral pressure is greatest whilst the body stands erect. These

localities are, A, the umbilicus, a point characterized as having given

passage (in the foetal state) to the umbilical vessels; D, the place

where the spermatic vessels and duct pass from the abdomen to the

testicle; and immediately beneath this, the crural arch, which gives

exit to the crural vessels. Herniae may happen at other localities, such

as at the thyroid aperture, which transmits the thyroid vessels; and at

the greater sacrosciatic notch, through which the gluteal vessels pass;

and all regions of the abdominal walls may give exit to intestinal

protrusion in consequence of malformations, disease, or injury. But as

the more frequent varieties of herniae are those which traverse the

localities, A, D, E, and as these, fortunately, are the most manageable

under the care of the surgical anatomist, we proceed to examine the

structures concerned in their occurrence.



A direct opening from within outwards does not exist in the walls of the

abdomen; and anatomy demonstrates to us the fact, that where the

spermatic cord, D F, and the femoral vessels, pass from the abdomen to

the external parts, they carry with them a covering of the several

layers of structures, both muscular and membranous, which they encounter

in their passage. The inguinal and crural forms of herniae which follow

the passages made by the spermatic cord, and the crural vessels, must

necessarily carry with them the like investments, and these are what

constitute the coverings of the herniae themselves.



The groin in its undissected state is marked by certain elevations and

depressions which indicate the general relations of the subcutaneous

parts. The abdomen is separated from the thigh by an undulating grooved

line, extending from C*, the point of the iliac bone, to B, the

symphysis pubis This line or fold of the groin coincides exactly with

the situation of that fibrous band of the external oblique muscle named

Poupart's ligament. From below the middle of this abdomino-femoral

groove, C B, another curved line, D, b, springs, and courses obliquely,

inwards and downwards, between the upper part of the thigh and the

pubis, to terminate in the scrotum. The external border of this line

indicates the course of the spermatic cord, D F, which can be readily

felt beneath the skin. In all subjects, however gross or emaciated they

may happen to be, these two lines are readily distinguishable, and as

they bear relations to the several kinds of rupture taking place in

these parts, the surgeon should consider them with keen regard. A

comparison of the two sides of the figure, PLATE 27, will show that the

spermatic cord, D F, and Poupart's ligament, C B, determine the shape of

the inguino-femoral region. When the integument with the subcutaneous

adipose tissue is removed from the inguino-femoral region, we expose

that common investing membrane called the superficial fascia. This

fascia, a a a, stretches over the lower part of the abdomen and the

upper part of the thigh. It becomes intimately attached to Poupart's

ligament along the ilio-pubic line, C B; it invests the spermatic cord,

as shown at b, and descends into the scrotum, so as to encase this part.

Where this superficial fascia overlies the saphenous opening, E, of the

fascia lata, it assumes a "cribriform" character, owing to its being

pierced by numerous lymphatic vessels and some veins. As this

superficial fascia invests all parts of the inguino-femoral region, as

it forms an envelope for the spermatic cord, D F, and sheathes over the

saphenous opening, E, it must follow of course that wherever the hernial

protrusion takes place in this region, whether at D, or F, or E, or

adjacent parts, this membrane forms the external subcutaneous covering

of the bowel.



There is another circumstance respecting the form and attachments of the

superficial fascia, which, in a pathological point of view, is worthy of

notice--viz., that owing to the fact of its enveloping the scrotum,

penis, spermatic cord, and abdominal parietes, whilst it becomes firmly

attached to Poupart's ligament along the abdomino-femoral fold, B C, it

isolates these parts, in some degree, from the thigh; and when urine

happens to be from any cause extravasated through this abdominal-scrotal

bag of the superficial fascia, the thighs do not in general participate

in the inflammation superinduced upon such accident.



The spermatic cord, D, emerges from the abdomen and becomes definable

through the fibres of the sheathing tendon of the external oblique

muscle, H, at a point midway between the extremities of the ilio-pubic

line or fold. In some cases, this place, whereat the cord first

manifests itself in the groin, lies nearer the pubic symphysis; but

however much it may vary in this particular, we may safely regard the

femoro-pubic fold, D, b, as containing the cord, and also that the place

where this fold meets the iliopubic line, C B, at the point D, marks the

exit of the cord from the abdomen.



The spermatic cord does not actually pierce the sheathing tendon of the

external oblique muscle at the point D, and there does not, in fact,

exist naturally such an opening as the "external abdominal ring," for

the cord carries with it a production of the tendon of the external

oblique muscle, and this has been named by surgical anatomists the

"intercolumnar fascia," [Footnote] the "spermatic fascia." The fibres of

this spermatic fascia are seen at D F, crossing the cord obliquely, and

encasing it. This covering of the cord lies beneath the spermatic

envelope formed by, a b, the superficial fascia; and when a hernial

protrusion descends through the cord, both these investing membranes

form the two outermost envelopes for the intestine in its new and

abnormal situation.



[Footnote: On referring to the works of Sir Astley Cooper, Hesselbach,

Scarpa, and, others, I find attempts made to establish a distinction

between what is called the "intercolumnar fascia" and the "spermatic

fascia," and just as if these were structures separable from each other

or from the aponeurotic sheath of the external oblique muscle. I find,

in like manner, in these and other works, a tediously-laboured account

of the superficial fascia, as being divisible into two layers of

membrane, and that this has given rise to considerable difference of

opinion as to whether or not we should regard the deeper layer as being

a production of the fascia lata, ascending from the thigh to the

abdomen, or rather of the membrane of the abdomen descending to the

thigh, &c. These and such like considerations I omit to discuss here;

for, with all proper deference to the high authority of the authors

cited, I dare to maintain, that, in a practical point of view, they arc

absolutely of no moment, and in a purely scientific view, they are, so

far as regards the substance of the truth which they would reveal,

wholly beneath the notice of the rational mind. The practitioner who

would arm his judgment with the knowledge of a broad fact or principle,

should not allow his serious attention to be diverted by a pursuit after

any such useless and trifling details, for not only are they unallied to

the stern requirements of surgical skill, but they serve to degrade it

from the rank and roll of the sciences. Whilst operating for the

reduction of inguinal hernia by the "taxis" or the bistoury, who is

there that feels anxiety concerning the origin or the distinctiveness of

the "spermatic fascia?" Or, knowing it to be present, who concerns

himself about the better propriety of naming it "tunica vaginalis

communis," "tunique fibreuse du cordon spermatique," "fascia

cremasterica," or "tunica aponeurotica?"]



The close relations which the cord, D F, bears to the saphenous opening,

E, of the fascia lata, should be closely considered, forasmuch as when

an oblique inguinal hernia descends from D to F, it approaches the

situation of the saphenous opening, E, which is the seat of the femoral

or crural hernia, and both varieties of hernia may hence be confounded.

But with a moderate degree of judgment, based upon the habit of

referring the anatomy to the surface, such error may always be avoided.

This important subject shall be more fully treated of further on.



The superficial bloodvessels of the inguino-femoral region are, e e,

the saphenous vein, which, ascending from the inner side of the leg and

thigh, pierces the saphenous opening, E, to unite with the femoral vein.

The saphenous vein, previously to entering the saphenous opening,

receives the epigastric vein, i, the external circumflex ilii vein, h,

and another venous branch, d, coming from the fore part of the thigh. In

the living body the course of the distended saphenous vein may be traced

beneath the skin, and easily avoided in surgical operations upon the

parts contained in this region. Small branches of the femoral artery

pierce the fascia lata, and accompany these superficial veins. Both

these orders of vessels are generally divided in the operation required

for the reduction of either the inguinal or the femoral strangulated

hernia; but they are, for the most part, unimportant in size. Some

branches of nerves, such as, k, the external cutaneous, which is given

off from the lumbar nerves, and, f, the middle cutaneous, which is

derived from the crural nerve, pierce the fascia lata, and appear upon

the external side and middle of the thigh.



Numerous lymphatic glands occupy the inguino-femoral region; these can

be felt, lying subcutaneous, even in the undissected state of the parts.

These glands form two principal groups, one of which, c, lies along the

middle of the inguinal fold, C B; the other, G g, lies scattered in the

neighbourhood of the saphenous opening. The former group receive the

lymphatic vessels of the generative organs; and the glands of which it

is composed are those which suppurate in, syphilitic or other affections

of these parts.



The general relations which the larger vessels of the inguino-femoral

region bear to each other and to the superficies, may be referred to in

PLATE 27, with practical advantage. The umbilicus, A, indicates pretty

generally the level at which the aorta bifurcates on the forepart of the

lumbar vertebrae. In the erect, and even in the recumbent posture, the

aorta may (especially in emaciated subjects) be felt pulsating under the

pressure of the hand; for the vertebrae bear forward the vessel to a

level nearly equal with, C C, the anterior superior spinous processes of

the iliac bones. If a gunshot were to pass through the abdomen,

transversely, from these points, and through B, it would penetrate the

aorta at its bifurcation. The line A B coincides with the linea alba.

The oblique lines, A D, A D,* indicate the course of the iliac vessels.

The point D marks the situation where the spermatic vessels enter the

abdomen; and also where the epigastric artery is given off from the

external iliac. The most convenient line of incision that can be made

for reaching the situation of either of the iliac arteries, is that

which ranges from C, the iliac spine, to D, the point where the

spermatic cord enters the abdomen. The direct line drawn between D and G

marks the course of the femoral artery, and this ranges along the outer

border, E, of the saphenous opening.





DESCRIPTION OF PLATE 27.



A. The umbilicus.



B. The upper margin of the pubic symphysis.



C. The anterior superior spine of the left iliac bone. C*, the situation

of the corresponding part on the right side.



D. The point where, in this subject, the cord manifested itself beneath

the fibres of the external oblique muscle. D*, a corresponding part on

the opposite side.



E. The saphenous opening in the fascia lata, receiving e, the saphenous

vein.



F. The lax and pendulous cord, which in this case, overlies the upper

part of the saphenous opening.



G. Lymphatic glands lying on the fascia lata in the neighbourhood of the

saphenous opening.



H. The fleshy part of the external oblique muscle.



a a a. The superficial fascia of the abdomen.



b. The same fascia forming an envelope for the spermatic cord and

scrotum.



c. Inguinal glands lying near Poupart's ligament.



d. A common venous trunk, formed by branches from the thigh and abdomen,

and joining--



e e. The saphenous vein.



f. The middle cutaneous nerve, derived from the anterior crural nerve.



g. Femoral lymphatic glands.



h. Superficial external iliac vein.



i. Superficial epigastric vein.



k. External cutaneous branches of nerves from the lumbar plexus.