540 



OBSTETRIC OPERA TIONS. 



there is sometimes a good deal of risk, so far as the maternal organs are 

 concerned ; and it is advisable to wrap twine, tow, or tape, around a 

 good portion of the blade towards the handle. 



The best instrument, if it is at hand, is a long, medium-sized trocar and 

 cannula, the end of the latter fitting closely on the stalk of the trocar, 

 which should be very sharp. It is introduced safely into the genital 

 canal by drawing the point sufficiently far back into the cannula as to be 

 entirely concealed. This end is then seized between the fingers and 

 thumb in such a way that the index-finger extends a little beyond the ex- 

 tremity of the cannula ; the other three fingers holding it in the palm of 

 the hand, while the right hand sustains and guides the instrument. 

 Should the trocar not fit the cannula tightly, the play between the two 

 renders their indroduction somewhat difficult, and the point may glide 

 through and wound the operator. The trocar may, in such a case, be 

 pushed quite through the cannula, and the point fixed in a cork which 

 can readily be knocked off by one of the fingers when the instrument has 

 reached the head of the foetus. Having arrived at this part, the proper 

 spot for puncture is selected, and then the instrument is applied to it — 

 perpendicular to its surface if possible, to prevent slipping. The trocar 

 is made to penetrate slowly by a slight rotatory motion from side to side, 

 and when all resistance ceases the cranium is perforated. This perfora- 

 tion should not be made at the sutures, if they can be avoided, as they 

 overlap and close the opening. The cannula is now held firmly in its 

 place by the left hand, the trocar is withdrawn by the right, and the fluid 

 escapes. The instrument should be sufficiently long for the end to be 

 near, or even outside, the vulva, when the point is on the cranium of the 

 foetus. 



There is no difficulty in performing this operation when the head pre- 

 sents first, even though it should not have entered the inlet, so long as it 

 is easily accessible to the hand. With the posterior presentation, how- 

 ever, the operation is troublesome ; as owing to the body of the foetus 

 occupying the passage, it is extremely difficult to pass the hand armed 

 with the trocar so far as the head. Nevertheless, it maybe accomplished 

 in many cases by patience and tact. There is no reason why the trocar 

 and cannula should not be passed through the mouth of the foetus in some 

 cases, and made to penetrate the cranium at the base of the skull, when 

 the frontal region cannot be attained. If the head cannot be reached in 

 this presentation, then exsection of the body of the young creature must 

 be practised, and the parts removed until the head can be manipulated. 



Craniotomy. 



Craniotomy or incisioJi of the cranium, is resorted to when puncture has 

 not sufficiently reduced the size of the head. It is an operation of great 

 antiquity in human obstetrics, and various instruments have been intro- 

 duced to facilitate its performance ; but very few of them have been util- 

 ized in veterinary obstetrics, and indeed for the larger domesticated an- 

 imals they are of no use. A simple straight or curved bistoury. Gunthers 

 sliding embryotom (Fig. 187), finger-scalpel (Figs. 185, 186). the long- 

 handled embryotom (Fig. 189), scalpel embryotom (Fig. 188), bone-chisel 

 (Fig. 193), or saw (Fig. 194), may one or all be employed, according to 

 circumstances. It cannot be denied, however, that the operation is very 

 difficult to execute, and not without serious danger for the parent. Even 



