Rose's explanation does not account for those cases in which the um bilical cord is normally constituted and no fistula of the urachus present, the navel ring closed, and the fissure confined to the lower portion of the bladder.
Such cases have been described by Gosselin, Bertet, and others. In these cases stricture of the umbilical cord cannot possibly have caused the rupture. At all events, most recent authorities agree that it is some hindrance to the emission of urine, and as Rose has proven, this may either be due to atresia of the urethra, or to absence of that organ. formerly thought that the prolapse of large and firm organs into the true pelvis might hinder the development of the urethra or even compromise its existence. Thus E. Rose once found the right kidney in the true pelvis; and T demonstrated, in the case that my pupil Dr. Kruger has de scribed, that the left lobe of a much enlarged liver and a whole bunch of small intestine filled the true pelvis, and protruded the diaphragms pelvis outward. Such an obstacle to micturition would of course only cause fissure of the bladder and not a fistula of the nrachus, when it occurs after the complete closure of the urachus. Nevertheless, complete ever sio of this kind does occur very early, even before the two halves of the allantois are fused. This Friedlander, E. Rose, and I myself have ob served. Between, in front of and above the double or single everted bladder, there were folds behind which a sound could be passed. (See Fig. 18.) They arise from the membrana reuniens inferior of Rathke, which closes the abdominal cavity before the skin and the muscle is de veloped, and forms the covering of fistuhe of the urachus, open bladder, and persistent allantoises. Where the pressure of the urine is strong, the bladders will touch one another, so that no solid body can exist be tween them; where it is weak the abdominal walls (abdominal plates) are formed as usual around the open bladders, and, when there are two, be tween them. From the instability of this inferior reuniting membrane the two bladders ultimately touch one another, and the remnants of the membrane form these bridge-like folds (Rose).
In these cases the same cause as a rule that determines the patency of the urachus, or the vesical eversion, will cause the abdominal walls to remain open, the lower portion of the recti muscles to waste, and pelvic deformity to occur. Of course deficiency of the abdominal walls may occur without fissure of the bladder; the whole organ then protruding through the belly walls, forming ectopia vesicw, which we shall con sider later. Ahlfeld's criticism of my c,ase has, however, taught me other
views. He objects to the assumption that an enlarged liver, a kidney lying in the pelvis, or a dilated stomach niay cause a vesical fissure, since the cleft is always symmetrical and centrally located; which could not possibly occur with a varying cause. At the time at which the vesical fissure must arise, the liver is yet too small to exercise any pressure effects u-pon the abdominal viscera, and the small intestine consists of only a fevi coils; the navel ring is then the locus minoris resistentim. We often lind an enlarged liver lobe in cases of umbilical hernia, but no yesical fissure. Finally, at the time at which the vesical fissure must begin, the urachus, is as thick as the intestine; it would certainly crowd out the delicate allantoic bladder at the tail end of the embryo if subjected to much pressure. For Ahlfeld believes that vigorous traction upon the urachus, when it projects to an abnormal extent beYond the tail end, would crowd out the allantois in front of the rectum, and prevent the union of the symphysis and of the external genitals.
AS there is no excretory passage for the allantois, it will fill and burst; the anterior wall will atrophy, and only the posterior become covered with mucous membrane. The intestine will open into the posterior bladder wall by one or more orifices. The rectum usually opens underneath the posterior bladder wall. Ruge and Fleischer deny this, and look upon the tense cord in question as a continuation of the urachus.
I myself believe that an early rupture of the urinary bladder occurs in consequence of urinary retention. To Rose's objection, that cicatrices are absent, I would reply that they are not present bec,ause the abdominal walls are not yet closed, and are thus not injured. Besides this I have several times seen children very shortly after birth, in whom the cord was quite normal, and yet a total inversion of the bladder was present. There seems to be no reason why rupture of the bladder from excessive disten sion during very early embryonal life, should not occur, as it does in extra-uterine life, when there is an impassable obstacle to micturition, as in retroflexio uteri gravida.