542 OBSTETPJCAL OPERATIOXS. 



Craniotomy. 



Craniotomii 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 introduced to facilitate 

 its performance ; but very few of them have been utilised in veterinary 

 obstetrics, and indeed for the larger domesticated animals they are of 

 no use. A simple straight or curved bistoury, Giiuther's sliding 

 embryotom (Fig. 200), finger-scalpel (Figs. 198, 199), the long-handled 

 embryotom (Fig. 203), scalpel embryotom (Fig. 201), bone-chisel (Fig. 

 207), or saw (Fig. 208), may one or all be employed, according to cir- 

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

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

 Even in woman, with all those advantages and appliances of which the 

 veterinary obstetrist cannot avail himself, craniotomy is always a for- 

 midable undertaking. The cephalotrihc and cranioclast, so useful in 

 human obstetricy, cannot be employed with our animals, it would 

 appear ; but there is no reason why modifications of these instruments 

 might not be devised to answer the same end. 



Hurtrel d'Arboval recommends that craniotomy be performed with a 

 convex probe-pointed bistoury (sharp on the convex border), the middle 

 of the cranium being incised ; then the fingers compress the bones, and 

 so effect delivery. 



Eainard advises two incisions on each side of the head, in the parietal 

 region. Giinther mentions that if, after puncture, the operator cannot 

 ■crush the bones of the cranium with the hand, they should be cut by 

 his secator, and removed piecemeal. Carsten Harms states that when 

 the head is an obstacle, it should always be crushed, if possible, the 

 bones being broken beneath the skin. Sometimes it is sufficient to 

 remove the lower jaw ; and in order to effect this, the jaw is first fixed 

 by a cord, the skin is then cut through on each side — from the com- 

 missure of the mouth to the temporo-maxillary articulation, the masseter 

 muscles and the ligaments being divided ; a transverse section of the 

 skin is now made between each joint, the finger separating it, and then 

 two or three assistants pulling at the cord, the jaw is removed. If it is 

 the transverse diameter of the head which forms the obstacle, the divi- 

 sion must be longitudinal, and great service may be derived from the 

 use of the bone-chisel — either Cartwright's or Margraff's pattern. As 

 much of the skin should be left as possible, in order to cover the jagged 

 ends of the bones. 



With the smaller animals, puncture and craniotomy are not at all 

 difficult operations, the bones being fragile and easily perforated or 

 crushed. 



Decapitation and Decollation. 



Decapitation, an operation which consists in separating the head 

 completely from the body, so as to allow these parts to be removed one 

 after the other, is not very often required ; and fortunately so, as it is 

 not without great danger to the parent. More frequently the head is 

 partially removed, the fore-limbs amputated, or evisceration of the chest 

 or abdomen — or both — practised, rather than resort to decapitation. 



Decollation is necessary when the neck is distorted and cannot be 

 straightened, and has to be divided at the point of curvature, the head 

 and portion of neck attached to it being then extracted. 



