Fehling's ° remarkable case is probably partly traumatic in its origin. The woman was sixty-three years old, and had had eleven deliveries anti one abortion. For fifteen years she had had a prolapsus which had been left to itself. One day, after going up to the fourth floor with a pail of water, it protruded very greatly, and she attempted to replace it forcibly with her hands. A fatal rupture of the posterior vaginal wall, with pro lapsed coils of intestine, occurred. The history of this case furnishes us with a key to a similar condition, which Rokitansky ' once found post mortem.
In these cases the traumatic influences were slight, and they may be placed by the side of the spontaneous cases. They presuppose au exces sive friability of the vaginal walls from a pathological process of some kind, together with a sudden increase in vaginal tension from ascites, retroversio uteri, or hernia post. vag., etc.
Now as to vaginal ruptures which occur sub-partu.
They occur both with natural and with artificial deliveries. If we do not include the very frequent fissures of the mucous membrane at the hymenal insertion, which occur in most first deliveries, vaginal ruptures are rare accidents in childbirth. In 108 cases of rupture M'Clintock counts 35 as affecting the vagina especially.' We can easily appreciate the conditions which predispose to vaginal rupture in childbirth. The excessive tension and stretching of the walls is the prime factor, especially when there is any disproportion between. the advancing part and the vaginal tube. An unequal amount of ten sion is therefore exerted; sometimes spontaneously by abnormal positions of the head, but much more frequently from a faulty direction of the for ceps in extraction. As a rule the posterior wall, being the one most sub ject to tension, is the one that is ruptured. The rapidity with which the vagina is dilated is a factor, as is also the condition of the vaginal tissue as regards extensibility. Deep fissures at the upper and lower segments of the tube generally involve the neighboring organs. Thus ruptures of the vaginal vault usually involve that of the cervix uteri; those near the vaginal entrance are continuous with perine,a1 rents. But we do see uncomplicated fissures at both places. Those of the vaginal vault then often form transverse tears, and sometimes spread so far in a circular form as to completely separate the uterus from the vagina. Hugenberger,
who has described this variety of rupture minutely under the name of kolpoporrhexis,' has collected 39 cases, the 40th occurring in his own practice. Seventeen of them were anterior, 17 posterior, and 6 more or less complete separation of vagina and uterus. Like uterine ruptures, they occurred most frequently in multiparce, in whom there was marked disproportion between pelvis and fcetus. In either case the essential cause of spontaneous rupture is the enormous stretching and tension of the cervical and vaginal walls, which occurs when there is an impassable obstacle, and the internal os is behind the head or other prominent part of the child. This mode of origin was described by Crantz, thoug,h G. A. Michaelis was the first to thoroughly study it.' Michaelis found in eight cases of rupture which he observed, that the vagina was always solely or especially the part involved. Bondi ' has proven the same origin for the more frequent cervical ruptures of the uterus, though he improperly denies the validity of the generally accepted explanation of vaginal rupture. Next to this the commonest e,ause is the exceptionally great extension of the vagina above an unyielding steno sis; this we have already mentioned when considering vaginal stenoses. (E. Kennedy, Doherty.) Ruptures from pressure of the soft parts be tween the child's head and pelvic prominences can probably only occur when the vagina has been enormously stretched and there are exostoses springing from the promontory or the sharp edge of the pecten pubis (Lehmann), or most commonly, the symphysis. It might also occur from too great prominence of the ischial spines, or from badly united fractures of the•pubis, with displacement and a large amount of callus.
We do not set any very high value upon spasmodic uterine contractions, or the influence of ergot as causes of rupture, though they have been much dwelt upon by the older authorities. We cannot in any of these older cases exclude the possibility of a want of proper mechanie,a1 rela tionship between the pelvis and the fcetus; and more recent confirmatory observations are wanting.