Surgical Anatomy Part 29

O. Saphena vein.

P P. Falciform margin of the saphenous opening.

Q. See Plate 38.

R. Sheath of the femoral vessels.

S. Anterior crural nerve.

T. The external ring.

[Ill.u.s.tration: Abdomen and leg, showing blood vessels, muscles and other internal organs.]

Plate 36

PLATE 37.

All the letters except the following indicate the same parts as in Plate 35.

F. The epigastric artery pa.s.sing between the two hernial sacs

G. The umbilical ligament.

H. The neck of the sac of the external hernia.

I. The neck of the sac of the internal hernia.

[Ill.u.s.tration: Abdomen, showing blood vessels, muscles and other internal organs.]

Plate 37

PLATE 38.--AN ANTERIOR VIEW OF PLATE 37.

All the letters, with the exception of the following, refer to the same parts as in Plate 36.

G. The funnel-shaped elongation of the fascia transversalis receiving g, the sac of the external bubonocele.

H. The sac of the internal inguinal hernia invested by h, the transversalis fascia.

Q. The spermatic vessels lying on the outer side of H, the direct inguinal hernia.

[Ill.u.s.tration: Abdomen and leg, showing blood vessels, muscles and other internal organs.]

Plate 38

COMMENTARY ON PLATES 39 & 40.

DEMONSTRATIONS OF THE NATURE OF CONGENITAL AND INFANTILE INGUINAL HERNIAE, AND OF HYDROCELE.

PLATE 39. Fig. 1--The descent of the t.e.s.t.i.c.l.e from the loins to the s.c.r.o.t.u.m.--The foetal abdomen and s.c.r.o.t.u.m form one general cavity, and are composed of parts which are structurally identical. The cutaneous, fascial, muscular, and membranous layers of the abdominal parietes are continued into those of the s.c.r.o.t.u.m. At the fifth month of foetal life, the t.e.s.t.i.c.l.e, 3, is situated in the loins beneath the kidney, 2. The t.e.s.t.i.c.l.e is then numbered amongst the abdominal viscera, and, like these, it is developed external to the peritonaeal membrane, which forms an envelope for it. At the back and sides of the t.e.s.t.i.c.l.e, where the peritonaeum is reflected from it, a small membranous fold or mesentery (mesorchium, Seiler) is formed, and between the layers of this the nerves and vessels enter the organ, the nerves being derived from the neighbouring sympathetic ganglia (aortic plexus), while the arteries and veins spring directly from the main abdominal bloodvessels. It being predetermined that the t.e.s.t.i.c.l.e, 3, should migrate from the loins to the s.c.r.o.t.u.m, 6 a, 7, at a period included between the sixth and ninth month, certain structural changes are at this time already effected for its sure and easy pa.s.sage. By the time that the testis, 5, is about to enter the internal inguinal ring, 6 a, (seventh or eighth month,) a process or pouch of the peritonaeal membrane (processus v.a.g.i.n.alis) has already descended through this aperture into the s.c.r.o.t.u.m, and the t.e.s.t.i.c.l.e follows it.

The descent of the testis is effected by a very slow and gradual process of change. (Tout va par degres dans la nature, et rien par sauts.--Bonnet.) But how, or by what distinct and active structural agent, this descent is effected, or whether there does exist, in fact, any such agent as that which anatomists name "gubernaculum testis," are questions which appear to me by no means settled.[Footnote]

[Footnote: Dr. Carpenter (Principles of Human Physiology) remarks, that "the cause of this descent is not very clear. It can scarcely be due merely, as some have supposed, to the contraction of the gubernaculum, since that does not contain any fibrous structure until after the lowering of the testis has commenced." Dr. Sharpey (Quain's Anatomy, 5th edition) observes, that "the office of the gubernaculum is yet imperfectly understood." The opinions of these two distinguished physiologists will doubtless be regarded as an impartial estimate of the results of the researches prosecuted in reference to these questions by Haller, Camper, Hunter, Arnaud, Lobstein, Meckel, Paletta, Wrisberg, Vicq d'Azyr, Brugnone, Tumiati, Seiler, Girardi, Cooper, Bell, Weber, Carus, Cloquet, Curling, and others. From my own observations, I am led to believe that no such muscular structure as a gubernaculum exists, and therefore that the descent of the testis is the effect of another cause.

Leaving these matters, however, to the consideration of the physiologist, it is sufficient for the surgeon to know that the testis in its transition derives certain coverings from the parietes of the groin, and that a communication is thereby established between the scrotal and abdominal cavities. ]

The general lining membrane of the foetal abdomen is composed of two layers--an outer one of fibrous, and an inner one of serous structure.

Of these two layers, the abdominal viscera form for themselves a double envelope. [Footnote] The testis in the loins has a covering from both membranes, and is still found to be enclosed by both, even when it has descended to the s.c.r.o.t.u.m. The two coverings of fibro-serous structure which surrounded the testis in the loins become respectively the tunica albuginea and tunica v.a.g.i.n.alis when the gland occupies the scrotal cavity.

[Footnote: Langenbeck describes the peritonaeum as consisting of two layers; one external and fibrous, another internal and serous. By the first, he means, I presume, that membrane of which the transversalis and iliac fasciae are parts. (See Comment. de Periton. Structura, &c.) ]

[Ill.u.s.tration: Abdomen and leg, showing blood vessels, muscles and other internal organs.]

Plate 39--Figure 1

PLATE 39, Fig. 2.--The t.e.s.t.i.c.l.e in the s.c.r.o.t.u.m.--When the t.e.s.t.i.c.l.e, 5, descends into the s.c.r.o.t.u.m, 7, which happens in general at the time of birth, the abdomino-scrotal fibro-serous membrane, 6 a, 6 d, is still continuous at the internal ring, 6 b. From this point downwards, to a level with the upper border of the t.e.s.t.i.c.l.e, the ca.n.a.l of communication between the scrotal cavity and the abdomen becomes elongated and somewhat constricted. At this part, the ca.n.a.l itself consists, like the abdominal membrane above and the scrotal membrane below, of a fibrous and serous layer, the latter enclosed within the former. The serous lining of this ca.n.a.l is destined to be obliterated, while the outer fibrous membrane is designed to remain in its primitive condition. When the serous ca.n.a.l contracts and degenerates to the form of a simple cord, it leaves the fibrous ca.n.a.l still continuous above with the fibrous membrane (transversalis fascia) of the abdomen, and below with the fibrous envelope (tunica albuginea) of the testis; and at the adult period, this fibrous ca.n.a.l is known as the internal spermatic sheath, or infundibuliform fascia enclosing the remains of the serous ca.n.a.l, together with the spermatic vessels, &c.

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 39--Figure 2

PLATE 39, Fig. 3.--The serous tunica v.a.g.i.n.alis is separated from the peritonaeum.--When the t.e.s.t.i.c.l.e, 7, has descended to the s.c.r.o.t.u.m, the serous tube or lining of the inguinal ca.n.a.l and cord, 6 b, 6 c, closes and degenerates into a simple cord, (infantile spermatic cord,) and thereby the peritonaeal sac, 6 a, becomes distinct from the serous tunica v.a.g.i.n.alis, 6 d. But the fibrous tube, or outer envelope of the inguinal ca.n.a.l, remains still pervious, and continues in this condition throughout life. In the adult, we recognise this fibrous tube as the infundibuliform fascia of the cord, or as forming the fascia propria of an external inguinal hernia. The anterior part of the fibrous spermatic tube descends from the fascia transversalis; the posterior part is continuous with the fascia iliaca. In relation to the t.e.s.t.i.c.l.e, the posterior part will be seen to be reflected over the body of the gland as the tunica albuginea, while the anterior part blends with the cellular tissue of the front wall of the s.c.r.o.t.u.m. The tunica v.a.g.i.n.alis, 6 d, is now traceable as a distinct sac,[Footnote] closed on all sides, and reflected from the fore part of the t.e.s.t.i.c.l.e, above and below, to the posterior aspect of the front wall of the s.c.r.o.t.u.m.

[Footnote: Mr. Owen states that the Chimpanzee alone, amongst brute animals, has the tunica v.a.g.i.n.alis as a distinct sac.]

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 39--Figure 3

PLATE 40, Fig. 1.--The abdomino-scrotal serous lining remains continuous at the internal ring, and a congenital hydrocele is formed.--When the serous spermatic tube, 6 b, 6 c, remains pervious and continuous above with the peritonaeum, 6 a, and below with the serous tunica v.a.g.i.n.alis, 6 d, the serous fluid of the abdomen will naturally gravitate to the most depending part--viz., the tunica v.a.g.i.n.alis; and thus a hydrocele is formed. This kind of hydrocele is named congenital, owing to the circ.u.mstance that the natural process of obliteration, by which the peritonaeum becomes separated from the tunica v.a.g.i.n.alis, has been, from some cause, arrested. [Footnote 1] As long as the ca.n.a.l of communication, 6 b, 6 c, between the tunica v.a.g.i.n.alis, 6 d, and the peritonaeum 6 a, remains pervious, which it may be throughout life, this form of hydrocele is, of course, liable to occur. It may be diagnosed from diseased enlargements of the t.e.s.t.i.c.l.e, by its transparency, its fluctuation, and its smooth, uniform fulness and shape, besides its being of less weight than a diseased testis of the same size would be.

It may be distinguished from the common form of hydrocele of the isolated tunica v.a.g.i.n.alis by the fact, that pressure made on the s.c.r.o.t.u.m will cause the fluid to pa.s.s freely into the general cavity of the peritonaeum. As the fluid distends the tunica v.a.g.i.n.alis, 6 c, 6 d, in front of the testis, this organ will of course lie towards the back of the s.c.r.o.t.u.m, and therefore, if it be found necessary to evacuate the fluid, the puncture may be made with most safety in front of the s.c.r.o.t.u.m. If ascites should form in an adult in whom the tunica v.a.g.i.n.alis still communicates with the peritonaeal sac, the fluid which acc.u.mulates in the latter membrane will also distend the former, and all the collected fluid may be evacuated by tapping the s.c.r.o.t.u.m. When a hydrocele is found to be congenital, it must be at once obvious that to inject irritating fluids into the tunica v.a.g.i.n.alis (the radical cure) is inadmissible. In an adult, free from all structural disease, and in whom a congenital hydrocele is occasioned by the gravitation of the ordinary serous secretion of the peritonaeum, a cure may be effected by causing the obliteration of the serous spermatic ca.n.a.l by the pressure of a truss. When a congenital hydrocele happens in an infant in whom the t.e.s.t.i.c.l.e, 5, Fig. 1, Plate 39, is arrested in the inguinal ca.n.a.l, [Footnote 2] if pressure be made on this pa.s.sage with a view of causing its closure, the t.e.s.t.i.c.l.e will be prevented from descending.

[Footnote 1: The serous spermatic tube remains open in all quadrupeds; but their natural p.r.o.ne position renders them secure against hydrocele or hernial protrusion. It is interesting to notice how in man, and the most anthropo-morphous animals, where the erect position would subject these to the frequent accident of hydrocele or hernia, nature causes the serous spermatic tube to close.]

[Footnote 2: In many quadrupeds (the Rodentia and Monotremes) the testes remain within the abdomen. In the Elephant, the testes always occupy their original position beneath the kidneys, in the loins. Human adults are occasionally found to be "testi-conde;" the testes being situated below the kidneys, or at some part between this position and the internal inguinal ring. Sometimes only one of the testes descends to the s.c.r.o.t.u.m.]

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 40--Figure 1.

PLATE 40, Fig. 2.--The serous spermatic ca.n.a.l closes imperfectly, so as to become sacculated, and thus a hydrocele of the cord is formed.--After the t.e.s.t.i.c.l.e, 7, has descended to the s.c.r.o.t.u.m, the sides of the serous tube, or lining of the inguinal ca.n.a.l and cord, 6 b, 6 c, may become adherent at intervals; and the intervening sacs of serous membrane continuing to secrete their proper fluid, will occasion a hydrocele of the cord. This form of hydrocele will differ according to the varieties in the manner of closure; and these may take place in the following modes:--1st, if the serous tube close only at the internal ring, 6 a, while the lower part of it, 6 b, 6 c, remains pervious, and communicating with the tunica v.a.g.i.n.alis, 6 d, a hydrocele will be formed of a corresponding shape; 2nd, if the tube close at the upper part of the t.e.s.t.i.c.l.e, 6 c, thus isolating the tunica v.a.g.i.n.alis, 6 d, while the upper part, 6 b, remains pervious, and the internal ring, 6 a, open, and communicating with the peritonaeal sac, a hydrocele of the cord will happen distinct from the tunica v.a.g.i.n.alis; or this latter may be, at the same time, distended with fluid, if the disposition of the subject be favourable to the formation of dropsy; 3rd, the serous tube may close at the internal ring, form sacculi along the cord, and close again at the top of the t.e.s.t.i.c.l.e, thus separating the tunica v.a.g.i.n.alis from the abdomen, and thereby several isolated hydroceles may be formed. If in this condition of the parts we puncture one of the sacs for the evacuation of its contents, the others, owing to their separation, will remain distended.