Demonstrations Of The Nature Of Congenital And Infantile Inguinal Herniae And Of Hydrocele

Sources: Surgical Anatomy

PLATE 39. Fig. 1--The descent of the testicle from the loins to the

scrotum.--The foetal abdomen and scrotum 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 scrotum. At the fifth month of foetal life,

the testicle, 3, is situated in the loins beneath the kidney, 2. The

t sticle 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 testicle, 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 testicle, 3, should migrate from the loins to the

scrotum, 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 passage. 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 vaginalis) has already

descended through this aperture into the scrotum, and the testicle

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 scrotum. The two coverings of fibro-serous structure

which surrounded the testis in the loins become respectively the tunica

albuginea and tunica vaginalis 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.) ]














PLATE 39, Fig. 2.--The testicle in the scrotum.--When the testicle, 5,

descends into the scrotum, 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 testicle, the canal of communication

between the scrotal cavity and the abdomen becomes elongated and

somewhat constricted. At this part, the canal 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 canal is destined to be obliterated, while the outer

fibrous membrane is designed to remain in its primitive condition. When

the serous canal contracts and degenerates to the form of a simple cord,

it leaves the fibrous canal 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 canal is known as the internal spermatic sheath, or

infundibuliform fascia enclosing the remains of the serous canal,

together with the spermatic vessels, &c.














PLATE 39, Fig. 3.--The serous tunica vaginalis is separated from the

peritonaeum.--When the testicle, 7, has descended to the scrotum, the

serous tube or lining of the inguinal canal 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 vaginalis, 6 d. But the fibrous tube, or outer envelope of the

inguinal canal, 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 testicle, 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 scrotum. The tunica vaginalis,

6 d, is now traceable as a distinct sac,[Footnote] closed on all sides,

and reflected from the fore part of the testicle, above and below, to

the posterior aspect of the front wall of the scrotum.



[Footnote: Mr. Owen states that the Chimpanzee alone, amongst brute

animals, has the tunica vaginalis as a distinct sac.]












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 vaginalis, 6

d, the serous fluid of the abdomen will naturally gravitate to the most

depending part--viz., the tunica vaginalis; and thus a hydrocele is

formed. This kind of hydrocele is named congenital, owing to the

circumstance that the natural process of obliteration, by which the

peritonaeum becomes separated from the tunica vaginalis, has been, from

some cause, arrested. [Footnote 1] As long as the canal of

communication, 6 b, 6 c, between the tunica vaginalis, 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 testicle, 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 vaginalis by the fact, that pressure made on the scrotum

will cause the fluid to pass freely into the general cavity of the

peritonaeum. As the fluid distends the tunica vaginalis, 6 c, 6 d, in

front of the testis, this organ will of course lie towards the back of

the scrotum, and therefore, if it be found necessary to evacuate the

fluid, the puncture may be made with most safety in front of the

scrotum. If ascites should form in an adult in whom the tunica vaginalis

still communicates with the peritonaeal sac, the fluid which accumulates

in the latter membrane will also distend the former, and all the

collected fluid may be evacuated by tapping the scrotum. When a

hydrocele is found to be congenital, it must be at once obvious that to

inject irritating fluids into the tunica vaginalis (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 canal by the pressure of a

truss. When a congenital hydrocele happens in an infant in whom the

testicle, 5, Fig. 1, Plate 39, is arrested in the inguinal canal,

[Footnote 2] if pressure be made on this passage with a view of causing

its closure, the testicle will be prevented from descending.



[Footnote 1: The serous spermatic tube remains open in all quadrupeds;

but their natural prone 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

scrotum.]














PLATE 40, Fig. 2.--The serous spermatic canal closes imperfectly, so as

to become sacculated, and thus a hydrocele of the cord is formed.--After

the testicle, 7, has descended to the scrotum, the sides of the serous

tube, or lining of the inguinal canal 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 vaginalis, 6 d, a hydrocele will be formed

of a corresponding shape; 2nd, if the tube close at the upper part of

the testicle, 6 c, thus isolating the tunica vaginalis, 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 vaginalis; 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 testicle, thus separating the tunica vaginalis 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.












PLATE 40, Fig. 3.--Hydrocele of the isolated tunica vaginalis.--When the

serous spermatic tube, 6 b, 6 c, becomes obliterated, according to the

normal rule, after the descent of the testicle, 7, the tunica vaginalis,

6 d, is then a distinct serous sac. If a hydrocele form in this sac, it

may be distinguished from the congenital variety by its remaining

undiminished in bulk when the subject assumes the horizontal position,

or when pressure is made on the tumour, for its contents cannot now be

forced into the abdomen. The testicle, 7, holds the same position in

this as it does in the congenital hydrocele. [Footnote] The radical cure

may be performed here without endangering the peritonaeal sac.

Congenital hydrocele is of a cylindrical shape; and this is mentioned as

distinguishing it from isolated hydrocele of the tunica vaginalis, which

is pyriform; but this mark will fail when the cord is at the same time

distended, as it may be, in the latter form of the complaint.



[Footnote: When a hydrocele is interposed between the eye and a strong

light, the testis appears as an opaque body at the back of the tunica

vaginalis. But this position of the organ is, from several causes,

liable to vary. The testis may have become morbidly adherent to the

front wall of the serous sac, in which case the hydrocele will distend

the sac laterally. Or the testis may be so transposed in the scrotum,

that, whilst the gland occupies its front part, the distended tunica

vaginalis is turned behind. The tunica vaginalis, like the serous

spermatic tube, may, in consequence of inflammatory fibrinous effusion,

become sacculated-multilocular, in which case, if a hydrocele form, the

position of the testis will vary accordingly.--See Sir Astley Cooper's

work, ("Anatomy and Diseases of the Testis;") Morton's "Surgical

Anatomy;" Mr. Curling's "Treatise on Diseases of the Testis;" and also

his article "Testicle," in the Cyclopaedia of Anatomy and Physiology.]










PLATE 40, Fig. 4.--The serous spermatic tube remaining pervious, a

congenital hernia is formed.--When the testicle, 7, has descended to the

scrotum, if the communication between the peritonaeum, 6 a, and the

tunica vaginalis, 6 c, be not obliterated, a fold of the intestine, 13,

will follow the testicle, and occupy the cavity of the tunica vaginalis,

6 d. In this form of hernia (hernia tunicae vaginalis, Cooper), the

intestine is in front of, and in immediate contact with, the testicle.

The intestine may descend lower than the testicle, and envelope this

organ so completely as to render its position very obscure to the touch.

This form of hernia is named congenital, since it occurs in the same

condition of the parts as is found in congenital hydrocele--viz., the

inguinal ring remaining unclosed. It may occur at any period of life, so

long as the original congenital defect remains. It may be distinguished

from hydrocele by its want of transparency and fluctuation. The impulse

which is communicated to the hand applied to the scrotum of a person

affected with scrotal hernia, when he is made to cough, is also felt in

the case of congenital hydrocele. But in hydrocele of the separate

tunica vaginalis, such impulse is not perceived. Congenital hernia and

hydrocele may co-exist; and, in this case, the diagnostic signs which

are proper to each, when occurring separately, will be so mingled as to

render the precise nature of the case obscure.














PLATE 40, Fig. 5.--Infantile hernia.--When the serous spermatic tube

becomes merely closed, or obliterated at the inguinal ring, 6 b, the

lower part of it, 6 c, is pervious, and communicating with the tunica

vaginalis, 6 d. In consequence of the closure of the tube at the

inguinal ring, if a hernia now occur, it cannot enter the tunica

vaginalis, and come into actual contact with the testicle. The hernia,

13, therefore, when about to force the peritonaeum, 6 a, near the closed

ring, 6 b, takes a distinct sac or investment from this membrane. This

hernial sac, 6 e, will vary as to its position in regard to the tunica

vaginalis, 6 d, according to the place whereat it dilates the

peritonaeum at the ring. The peculiarity of this hernia, as

distinguished from the congenital form, is owing to the scrotum

containing two sacs,--the tunica vaginalis and the proper sac of the

hernia; whereas, in the congenital variety, the tunica vaginalis itself

becomes the hernial sac by a direct reception of the naked intestine. If

in infantile hernia a hydrocele should form in the tunica vaginalis, the

fluid will also distend the pervious serous spermatic tube, 6 c, as far

up as the closed internal ring, 6 b, and will thus invest and obscure

the descending herniary sac, 13. This form of hernia is named infantile

(Hey), owing to the congenital defect in that process, whereby the

serous tube lining the cord is normally obliterated. Such a form of

hernia may occur at the adult age for the first time, but it is still

the consequence of original default.












PLATE 40, Fig. 6.--Oblique inguinal hernia in the adult.--This variety

of hernia occurs not in consequence of any congenital defect, except

inasmuch as the natural weakness of the inguinal wall opposite the

internal ring may be attributed to this cause. The serous spermatic tube

has been normally obliterated for its whole length between the internal

ring and the tunica vaginalis; but the fibrous tube, or spermatic

fascia, is open at the internal ring where it joins the transversalis

fascia, and remains pervious as far down as the testicle. The intestine,

13, forces and distends the upper end of the closed serous tube; and as

this is now wholly obliterated, the herniary sac, 6 c, derived anew from

the inguinal peritonaeum, enters the fibrous tube, or sheath of the

cord, and descends it as far as the tunica vaginalis, 6 d, but does not

enter this sac, as it is already closed. When we compare this hernia,

Fig. 6, Plate 40, with the infantile variety, Fig. 5, Plate 40, we find

that they agree in so far as the intestinal sac is distinct from the

tunica vaginalis; whereas the difference between them is caused by the

fact of the serous cord remaining in part pervious in the infantile

hernia; and on comparing Fig. 6, Plate 40, with the congenital variety,

Fig. 4, Plate 40, we see that the intestine has acquired a new sac in

the former, whereas, in the latter, the intestine has entered the tunica

vaginalis. The variable position of the testicle in Figs. 4, 5, & 6,

Plate 40, is owing to the variety in the anatomical circumstances under

which these herniae have happened.