In infants only congenital oblique inguinal hernia are found.
I have never observed a case of direct inguinal hernia in children, perhaps because in children the inguinal canal runs straight and both openings, although wider, are situated nearly one above the other (Bahimann).
If the processus vaginalis is completely patent it is called a com plete hernia. It extends clown into the scrotum, 'even if the testicle already lies there, for nearly all cases of incomplete descent are accom panied by complete hernia, as may be understood from the conditions of development (Fig. 36).
If the processus vaginalis is closed at its lower end and abdominal contents enter the open abdominal portion, it is an incomplete hernia. This may extend also into the scrotum, but even then the entire cir cumference of the testicle lies outside the hernial sac.
As in the case of other ducts lined with mucous membrane or endo thelium, which when partially occluded may lead to cyst formation, cystic tumors may develop in the processus vaginalis, and these are called hydroceles. They may be combined with hernia in many varia tions, and may remain in communication with the abdomen by a minute gap (hydrocele communicans).
It is very often found that in children the seminal cord, artery, veins, nerves, and vas deferens are not united in one cord, but are dis tributed along the circumference of the processus vaginalis in accordance with the disturbances of development they have undergone, and it is only after becoming detached in incomplete hernia that they unite as in the adult and, as a cord, proceed to the testicle.
Lateral prolapses between the layers of the inguinal canal sionally occur in front of the peritoneum or between the muscles, ducing the rare types of hernia—properitoneal, interstitial, or superficial. Remembering the similarity of development in the female, we find there is a resemblance in the development of inguinal hernia. The canalis Nuckii represents the inguinal canal and the processus vaginalis passes all the way along the round ligament into the labia majora. By following these (Pails of .development it is possible to explain easily the external pathological anatomy.
In the event of a complete hernia the testicle lies in its wall, pro truding by half its ,sice, as it also does in hydrocele of the testis. The seminal cord always runs at the outer wall of the hernial sac, lint as the latter may be exceedingly thin it will sink into the epididymis.
As mentioned before, the testicles as well as the last part of the seminal cord are not connected with the hernial sac. although an exten sive hernia may by its weight gravitate into the scrotum so that the base of the hernial sac may be contiguous to the testicle.
In both forms any kind of abdominal contents may be found within the sac, such as oment um, coils of small intestine, very often the crecum and appendix; in females the ovaries (Figs. 37a and 37c). The intes tinal coils and parts of the omentum which may be found in the hernial sac are generally reducible in herniie which are not adherent to the sac and can be completely returned into the abdominal cavity.
The case is different if the ciecum with its broad surface, together with the parietal peritoneum, is dragged into the hernial sac. The appendix with its mesentery is adherent to the hernial wall, and, simi larly, the cmcum may be adherent with its broad surface to the hernial wall, which at this place has of course originated from the parietal part of the peritoneum.
These conditions are, of course, subject to variations. For instance, anomalies are not rare in which the clecum and the entire colon, hay ing a free mesentery, may, together with loops of the small intestine, find their way into the left hernial sac. In this case they are just as easily reducible as hernhe containing free coils and omentum. Other wise difficulty in reducing right-sided hernia points with great prob ability to the and appendix as contents. (Personal observation of 16 cases.) (Fig. 37a.) It has been mentioned More that in abnormal development of a descended ovary the latter may lodge in a hernial sac of the labia majora. This is not a rare occurrence in female infants.
It is intelligible from the anatomical conditions that the hernial ring becomes considerably distended by the bulky contents and its fre quent passage through the same. The fascial bundles, or pillars, con tinue to diverge. The sphincters become atrophied from want of use, while the cremaster is the only muscle that becomes hypertrophied; surrounding the hernial sac, it tries as a kind of self-help to prevent exaggerated distention of the hernial sac (Goldner, Bayer), thus form ing a natural suspensory.
It occasionally happens not only that the serous coverings are tuberculous, but also that the inner wall of the hernial sac is studded with typical tubercles. (Observation of four cases.) The symptoms of an incipient as well as of a developed reducible hernia are visible externally only as a rule.
A tumor of the inguinal canal, whether it lies in the canal itself, above it, or extends into the scrotum, arouses even in laymen the sus picion of hernia. If the contents can he pressed back into the abdomen, eliciting an audible intestinal gurgle, then the diagnosis is beyond doubt. In the absence of these symptoms, there can be confusion only with a hilocular hydrocele or one that communicates with the abdominal cavity. Translucency of the contents, palpation (elastic fluctuation), and percussion (air) will decide the question. A displaced testicle in the inguinal canal will be recognized by the fact of its absence in the normal place.
The differential diagnosis in irreducible hernia may present greater difficulties. But here, again, careful physical examination will prevent mistaking it for a unilocular hydrocele, without having to resort to a test puncture. When the hernia is tense, elastic and irreducible the condition is usually so serious that it can be recognized from the patient's general condition. Here we have to deal with a