The crochets of Kidd, of Tarnier, of Hubert, of Wasseige, of Stanesco, are certain ones articulated, and others not.
d. Embryotonies which act by pressure or laceration.—The simplest of all is Braun's blunt hook. It is composed of a steel bar bent at an acute angle in the shape of a crook. (Fig. 177.) The festal arm is pulled down as much as possible in order to make the neck accessible. The left hand is introduced into the vagina and one or two fingers are passed around the neck. The hook is then passed flat along the hand and behind the ketal neck, guided by the fingers. The handle of the instrument is then lifted up, and vigorous traction made horizontally until the ligaments of the vertebral column are heard to rupture. The hook is then turned around several times, traction being simultaneously made. The vertebral column and the tissues are thus torn. The fingers should not be with drawn during this manoeuvre, since they are there to protect the mater nal parts against injury. The foetal trunk is readily extracted by pulling on the arm, and the head may be removed either by the hand, the for ceps or the cephalotribe. (Fig. 178.) Pierre Thomas has devised an apparatus which consists in: 1. Braiin's hook. 2. A chain-saw. 3. A vaginal protector.
Braun's hook is perforated for the passage of the chain-saw, and is used for passing the chain around the foetal neck. This accomplished, the hook ill withdrawn, and the two ends of the chain passed through the tubes of the vaginal protector (Fig. 179, B), and the neck is sectioned by working the chain. Thomas says of his method: " We believe that it has the following advantages over Braun's: 1. The maternal parts cannot be injured either by the hook or the chain. 2. The operation is less painful. and is more certain and rapid." We have already stated that Barnes carries an eeraseur wire by means of Ramsbotham's hook, in order to perform brachiotomy.
The two most recent embryotomes are that of Tarnier and that of Thomas, which is simply a modification of Tarnier's.
Tarnier's embryotome is composed of two blades, two conducting rods, a chain-saw. One blade is called the posterior and the other the anterior. These blades are grooved. The posterior blade is curved to fit into the concavity of the sacrum. The anterior blade is slightly curved for inser tion between the fcetus and the pubes. The blades are applied around the foetus, and are locked and screwed down until the handles are close together. The chain is then pushed through the groove in the blades by
means of the conducting rods, and worked along as well by the screw key. The foetus is divided from below upwards. The entire thickness of the body may be cut through in five seconds, according to Tarnier.
Thomas's latest embryotome consists of two blades, two stylets, a special saw. (Fig. 181.) The instrument is used as follows: The posterior blade is inserted behind the neck or the trunk of the foetus, and the an terior blade in front. The blades are locked and brought in apposition. The chain-saw is then carried by the stylets through the blades. The instrument is steadied by an assistant, and by rapid to-and-fro movements of the chain the foetus is sectioned from below downward. The mater nal parts run no risk of being damaged by the saw, being protected by the blades of the instrument.
We see then that it is not instruments which are lacking. The real difficulty in embryotomy is the contraction of the uterus. Where then the blunt hook cannot pass, the same will hold true of other instruments. The simplest method is that of Braun, but it requires an amount of force which may be dangerous to the mother. The same does not hold true of Dubois's scissors. We should then prefer them, resorting to Pajot's device if they failed. In every case where we have been called upon to detruncate or eviscerate, Dubois's scissors have answered us well. We have had six successes in seven cases.
After decapitation the body of the foetus readily follows on traction on the arm. The head may give us trouble. In case it resists our gentle efforts with the hand, forceps or cephalotribe, we may try a blunt hook inserted into the mouth.
Embryotomy is always a grave operation. The mortality rate is, there fore, high, even where practised with the greatest possible care and ex pertness.
Such are the operations which may' be practised on the foetus. May they be compared one with another, from the standpoint of the results which they give for the mother and the infant ? We do not think so; the conditions vary too markedly according to the case, the mode of interven tion and the necessity. The statistics which we have given, it should be remembered, have been copied and recopied, and they vary much accord ing to each author. There is further the element of expertness, which we must take into account, and which explains fully the success of some where others have failed.