VAGINAL HYSTEROTOMY 209 



brane, possesses many transverse folds, which secrete a viscid, 

 opalescent slime during pregnancy, sealing hermetically the 

 canal of the cervix uteri. 



The submucosa is rich in elastic and fibrous fibres, its 

 lower portion having many veins and some arteries. 



The muscularis, lying between the mucosa and serosa, is 

 made up of concentric fibres, forming, so to speak, a sphincter 

 muscle, and therefore designated sphincter cervicis. The outer 

 muscular layer consists of longitudinal fibres, which are lost in 

 the vagina. The external face shows a serosa, the peritoneum, 

 which to some extent covers the vagina, reduplicates and lines 

 the rectum. The excavation thus formed represents the so- 

 called excavatio rectovaginalis. 



During dilatation of the cervix the canal is partly opened 

 by the uterine contractions, gradually involving the cervix, 

 partly by the mechanical action of the water-bag. This dila- 

 tation is so considerable on account of the many elastic fibres 

 and numerous folds of the palma plicata, that the corpus uteri 

 and vagina form one wide canal for the passage of the fcetus. 



Indications. — When the above described dilatation does not 

 occur, the birth of the fcetus stops. Many causes may produce 

 insufficient dilatation. We have seen already that in many 

 instances dilatation can be effected with the fingers or with the 

 hand. It was also pointed out that many conditions may be 

 mistaken for spasm of the cervix or obliteration of the cervical 

 canal. Obliteration of the cervical canal is the only indication 

 for hysterotomia vaginalis. It may be the result of a carti- 

 laginous-like degeneration, from cicatricial tissue or adhesions 

 between the walls of the cervical canal following injuries. In 

 those cases conception took place at a time when the canal was 

 still open and the wound not yet completely healed. The in- 

 jury was received at a previous birth. 



Should the diagnosis be doubtful, mechanical dilatation 

 must first be attempted. Forcible dilatations must remain the 

 last resort. 



Details of the Operation. — Balestra already in 1816 per- 

 formed vaginal hysterotomy in the cow after the Eicherand 



