In dissecting this rupture from without, or in operating upon it in the living, it will be found to lie at a different depth from the sur face, and to possess variety in the number of fascial coverings according to its position with reference to the parts already described. Thus it may be placed within the crural canal, within that triangular space formed by the fascia lata ; or having passed beyond its inferior opening or falciform edge, it may present more superficially. In the former case, after the division of the common integuments, the skin and fat, the superficial fascia is exposed and may consist of many layers—at all events of two : next is the dense and resisting fascia lata of the thigh ; and deeper still, the funnel shaped fascia in which the crural ring is situated. Between this latter and the sac another fascia has been described under the name of the fascia propria, which may be supposed to be formid by a condensation of that cellular tissue already described as occupying the crural ring ; but I have never been able to satisfy myself as to the existence of this as a distinct membrane, and I must again caution the young operator not to expect to meet with lamina of fascia as de scribed or demonstrated by the anatomist. A dexterous and careful dissector may make al most as many layers of fascia as lie pleases.
After it has passed the inferior border of the crural canal and appeared more externally, the coverings of fascia to be expected must depend on the view taken of the anatomy of this part. If it is believed that the hernia having cleared this point merely swells out on being relieved from the pressure, without passing or pushing through any of the superincumbent structures, then in order to come down upon the sac it would be necessary to divide the skin and cellular tissue, the different laminw of the fascia superficialis, the cribrifurin portion of the fascia lata, the anterior portion of the funnel-shaped fascia, and the fascia propria. If, on the other hand, it is supposed that the hernia has escaped through one of the openings in the femoral sheath, and a corresponding one in the iliac portion of the fascia lata, it will lie more super ficial by the absence of these investments. Iu either case the last layer of fascia most adja cent to the sac is almost always remarkable for density and strength.
The general symptoms of this affection are the same with those of inguinal, such as the appearance of the tumour, its diminution or disappearance in the recumbent position, and the impulse imparted to it by coughing, sneez ing, &c.: its peculiar symptoms are explicable by its anatomical relations. I. The crural hernia is generally small and its increase slow : the size of the ring and the compression ex ercised on it by so many superincumbent layers of fascia will be sufficient to account for this, and also will skew why this rupture is almost always painful, and why position has so much effect on it, relief being constantly ob tained by bending the thigh on the pelvis and rotating the limb inwards. 2. The peculiar manner of growth, its first passing downwards, then forwards, and then upwards and inwards, is caused by the attachment of the funnel-like fascia to the vessels at the superior part of the thigh, and by that of the fascia supelficialis to the fascia lata near the entrance of the saphena vein ; thus its shape is never pyramidal like that of inguinal ; it is globular or oval, and its longest diameter is transverse. 3. I have already mentioned its prevalence amongst females advanced in life.
As the testicle is more subject to disease than any structure at the top of the thigh, there are more affections with which scrotal hernia may be confounded ; but on the other hand, when a doubt arises on the subject of crural hernia, the diagnosis is vastly more difficult, and often the surgeon has to be guided by the gene ral symptoms of peritoneal inflammation rather than by the results of local examination, how ever carefully performed. Mr. Cones* states that "this species of hernia is liable to stran gulation even before it can be felt externally," —an observation I was enabled to verify a few months since in a ease where a very small knuckle of intestine had not passed the inferior aperture of the femoral canal, but was lodged in an absorbent gland, which seemed to have been hollowed out to receive it.t But the
hernia may be much larger and still not disco verable in consequence of some unfortunate complication : I have seen a case of incarce rated hernial in which an abscess was seated at the superior part of the thigh immediately in front of the sac; and after the pus had been evacuated, some time elapsed before decisive symptoms pointed out the existence of the more formidable disease behind. There is, in the Museum in Park-street, a preparation exhibiting a fatty tumour growing on the exter nal surface of a hernial sac. The patient from whom it was taken was the subject of opera tion, and after the integuments and fascia had been divided and this tumour presented, some doubts were at first entertained as to the pre sence of a hernia beneath it ; but on careful examination the operator discovered the hernial tumour, and cutting cautiously through the other, opened the sac, in which a knuckle of intestine was found incarcerated. The opera tion was successful, and the patient recovered. "In many instances," says Mr. Colles, "the difficulty of discriminating the disease is consi derably increased by an enlarged lymphatic eand lying anterior to a very small hernia." Perhaps there are no two affections more liable to be mistaken for each other than erural hernia and an enlarged lymphatic gland; and however apparently distinct the two affections may be, and however easy it may seem to furm a diagnosis in theory, still the best surgeons speak of the difficulty of discriminating between them, and many acknowledge having fallen into the error themselves. It has happened that a patient has had a hernia on one side and an enlarged gland on the other, and when symptoms of strangulation became urgent, it was the gland that was considered to be the most prcssing,and it was selected for the opera tion. I recollect two cases which occurred nearly at the same time ; one in which there was a very minute hernia at the left groin, which had been regarded as a swelled gland, and the patient died of the effects of its stran gulation; the other a case of pure peritoneal inflammation, in which the patient happened to have a swollen gland in the groin, which was actually cut down upon and exposed, but the operation did nut much injury, for the patient subsequently recovered. It has been said that a diagnosis can be established by attention to the following circumstances. The hernia fol lows on some sudden exertion, on a blow or a fall, and appears suddenly and at once ; whereas the gland in the commencement is very small, perhaps like a moveable kernel, and increases slowly and by degrees. Besides, this diagnostic will be greatly assisted if there is a chancre or other sore to account fur the irri tation and inflammation of the gland; but on the other hand the hernia does not always assume its given size at once, it is often su small at the beginning that the patient is not aware of its existence, and so far from appear ing suddenly after a violent exertion it may have been present fur months without being perceived, The hernia receives an impulse from coughing or sneezing, and retires or be comes smaller in the recumbent posture, which are not observed to happen with the gland ; but then an enlarged gland may be complicated with a hernia, and the symptoms so mixed and confused that a diagnosis may be very difficult. It is said that a gland may be moved about and withdrawn from its situation in a slight degree, and if it can there is no great danger of mis taking it; but when it has arrived at the size or occupies the place which could make it resem ble a hernia, then it does not admit of being moved under the fascia, and the diagnosis is almost impossible. Fortunately, a crural hernia does not often consist of omentum, but when it does there is nothing more likely to exhibit the characters of a gland in a state of chronic dis ease, and I know not how the two cases can be accurately distinguished. Here the physical evidence derived from a gentle percussion (as already noticed) is utterly and completely valueless.