Cleidotomy

CLEIDOTOMY, cleidotomia (from Greek cleis—clavicle and temno—I cut), an obstetric operation involving the transection of one or both clavicles of the fetus for the purpose of reducing its shoulder girdle. The necessity for using cleidotomy arises when it is impossible for the fetus to pass through the birth canal without reducing the volume of its shoulders. Such an impossibility is created by a spatial discrepancy between the size of the fetal shoulder girdle and the dimensions of the mother's pelvis and depends, aside from rare cases of malformations, either on the excessive development of the fetus (so-called giant children, according to Winter, over 5,000 g) with a normal maternal pelvis, or on the narrowness of the latter with a normal weight and size of the fetus, and sometimes on both together, whereby the narrowing of the pelvis in such cases may be relatively insignificant, and the weight of the fetus may exceed the average norm by 0.5 kg or slightly more. Cleidotomy is performed either as an additional procedure for the extraction of a previously perforated fetus, in which the shoulders become stuck in the narrowed pelvis following the extraction of the head, or as an independent operative aid when the need for it is felt after the spontaneous birth of an unreduced head or its extraction with forceps. In the first case, it is a variety of embryotomy in general and is combined, besides perforation, with other methods of reducing the child. Thus, Herff in 1889, in addition to cleidotomy, also applied the transection of the 2 upper ribs in his case. As a distinct operation, cleidotomy was first proposed in 1895 by Prof. Fenomenov, who emphasized its independence, typicality, and simplicity of execution and gave it the name cleidotomia. However, according to Perondi, this operation was pointed out as early as 1887 by Fornani. With a known disproportion between the fetal shoulder girdle and the mother's pelvis, the head, having been born spontaneously or with the help of forceps from the genital slit, does not perform an external rotation; the face thus remains pressed against the perineum due to the fact that the shoulders at this moment are in the transverse or oblique diameter of the pelvic inlet or above it. An attempt to bring down the fetus by the born head encounters elastic resistance, forcing the head to 'retreat' back into the genital slit. In order to palpate the neck of the fetus and orient oneself to the position of the shoulders, one must insert fingers deep into the birth canal. When there is difficulty in the passage of the shoulders through the birth canal, one should attempt to pull energetically on the head, simultaneously assisting the advancement of the fetus by pressing on the fundus of the uterus along the axis of the pelvic canal. Upon the failure of this attempt, 2-4 fingers are inserted into the birth canal, and one attempts either to change the position of the shoulders, moving them from the transverse to the direct or oblique diameter if the shoulders have entered the pelvis, or into the oblique if they are at the pelvic inlet or above it. Next, an attempt to advance at least one shoulder with a finger inserted into the axillary cavity, or (on the advice of Bumm) to bring down the arm of the fetus, is appropriate. All these attempts, however, may not yield a result. In such cases, Fenomenov recommends resorting to cleidotomy. The technique of cleidotomy consists of the following: having pulled the head strongly to the side, the corresponding hand is inserted into the genital canal, under the control of which the clavicle is transected on one side with long, blunt-pointed, strong scissors (of the Fenomenov type), and then the same is done on the other side. The ends of the transected clavicles shift and overlap each other, due to which the biacromial diameter is reduced. The shoulder girdle, reduced in volume (up to 5 cm according to Liebich), slips through the pelvic canal during energetic downward pulling on the head. One can limit oneself to the transection of only one clavicle; to facilitate the passage of the shoulders in this case, it is recommended to bring down the arm, which is significantly facilitated thanks to the preceding cleidotomy. If, even after the transection of the clavicles, pulling on the head does not yield a result, pulling the fetus with a finger or fingers inserted into the axillary cavity facilitates the passage of the shoulders. This last measure can be replaced by pulling with the help of a hook applied (as Jolly advises) from the side of the chest. Descriptions of cases of using cleidotomy on a living fetus (as far as is known) do not exist. However, it is theoretically conceivable (Strassmann, Liebich) to perform cleidotomy in these cases as well. Bearing this possibility in mind, Liebich advises, in the resulting situation, not to waste time on other attempts to extract the shoulders, but to immediately proceed to cleidotomy, and in order to avoid injuring vessels, he advises performing the transection of the clavicles with the help of a Gigli saw, introduced behind the clavicle with an aneurysm needle after a preliminary incision of the skin over the clavicles. However, it is possible to avoid injuring vessels even when transecting the clavicles with the indicated blunt-pointed scissors, as proven by the case of Strassmann. After cleidotomy on a living fetus, the use of a hook is not recommended due to the possibility of damaging the vessels and nerves of the axillary cavity. Cleidotomy, proposed by Fenomenov as an independent, typical, and simple obstetric operation, having found quite numerous supporters and followers (e.g., Strassmann, Liebich, and others), met with objections from Jolly, who points out that this operation is not technically simple and does not achieve its goal by itself, because with its help, the mechanism of shoulder passage is not changed, according to which, for their successful passage through the birth canal, one shoulder must first descend into the pelvis, and then the other. This circumstance, in the opinion of Jolly, both in his two cases and in cases of the use of cleidotomy by others, caused the need for the subsequent application of a hook, bringing down the arm, etc.