Inflamed tissues at a certain epoch do, it is said, become soft and friable ; why should it not be so in mucous or villous tissues ? Although this reasoning proves nothing,—for we cannot judge from analogy in a graphic science like pathological anatomy,—yet it is the simple expression of the truth, because it is certain that mucous tunics are softened by inflammation, but this softening does not re semble in any thing the idiopathic softening.
Rupture of the bladder is a more frequent occurrence than that of the oesophagus, the stomach, or the intestines ; it occurs sometimes without external violence, simply by a distention of the organ, from a prolonged retention of urine ; most commonly, however, it is produced by a violent blow, or the passage of the wheel of a carriage over the hypogastrium, or the violent efforts to which a woman is subject during the pains of labour, the bladder being in a state of plenitude. In the first case, the rupture usually occurs near the insertion of the ureters or the neck of the bladder, because it is at these points that the distended organ usually begins to thin and tear. In the second case it is usually at the inferior fundus of the organ that the rupture is found.
We have already pointed out the circum stances under the influence of which the blad der may be ruptured, and we have stated that the extravasation of urine by which it is fol lowed is commonly productive of fatal Con sequences.
In a certain but small number of cases, the patient is able to resist .the inflammatory symptoms which are developed, urinary ab scesses are formed, which may open either in the vicinity of the umbilicus, at the hypo gastrium, in the inguinal region, in the vagina, at the perineum, or in the rectum, and a fistu lous canal is organised.
Emile. Fistulous communications be tween the bladder and the vagina or in testines are commonly the result of purely mechanical causes, such as the action of a calculus which may destroy the recto-vesical septum, the action of a foreign body introduced into the anus and penetrating the bladder, the lateralised or recto-vesical operation for stone, the operation of lithotrity, or as a con sequence of the pressure produced by the head of the child in parturition. Vesico-in testinal fistulae sometimes establish a com munication between the bladder and the ileum or colon," and then the summit of the bladder is usually the seat of injury. When the com munication is established between the bladder and the rectum, the posterior surface of the bladder is commonly implicated ; the neck of the bladder may, however, be similarly affected, and then it is commonly owing to the action of a calculus or other foreign body directed upon this portion of the vesical parietes. At
other times the lesion succeeds to chronic in flammation, or to a cancerous ulcer which has extended from the rectum to the bladder; and then the perforation almost always exists near the neck of the latter. The communication of the intestine with the bladder is sometimes established without abscess, without external inflammation. Sometimes the urine does not escape by the rectum, while faecal matter and flatus pass from the rectum into the bladder.
Ordinarily, however, the urine passes into the rectum and often causes diarrhoea; the bladder, distended by intestinal gas, forms a sonorous and painful tumour at the hypo gastri u rn Vesico-vaginal fistulae are sometimes though rarely occasioned by the action of a foreign body introduced into the vagina; sometimes they are the result of the progress of a uterine cancer ; but in general the cause by which they are produced is a laborious accouchement, during which the head of the infant has re mained long in the passage, and has by its pressure determined gangrene of the vesico vaginal septum. The accident may be pro duced by the imprudent use of instruments ; but this is a rare occurrence, perhaps for the reason that instruments are comparatively un frequently employed. In a few days the eschars which are the result of that gangrene are thrown off, and the consequent loss of sub stance may then be demonstrated. We find that these fistulae have not always the same form, the same direction, nor the same extent. In some cases they are longitudinal, at other times transverse ; in others their form is irre gular. The extent of the loss of substance is also very variable : sometimes the fund us of the bladder is extensively destroyed, so much so as to allow of the opposite parietes of the organ being implicated in the opening, and forming a true vesico-vaginal hernia. When the disease is a vesico-umbilical fistula, the com munication is with the summit of the bladder, and is commonly caused by a dilatation of the urachus or by the prolongation of the mucous membrane of the bladder, which is directed along the cord produced by the conversion of the urachus and the vessels by which it is accompanied into a cellular structure.* In either case the disease is almost invariably a consequence of the existence of some ob stacle to the passage of urine along the urethra.