NECK. 



573 



except a proposal made by M. Malgaigne* 

 for reaching the larynx through it, which 

 has not yet received the sanction of practice. 

 2. Theangle,in which the a'.ae of the thyroid car- 

 tilage meet, having under the quaint name of 

 pomum Adumi its extreme prominence above. 

 Within it are the essential organs of voice, 

 which, buckler-like, it protects: the inward 

 aspect of its angle attaches the vocal ligaments ; 

 its outward jutting marks their length, and mea- 

 sures the development of the larynx. Hence 

 the pomum Adumi, as indicating by its promi- 

 nence that matured growth of the organs of 

 voice, which belongs to male puberty, is a phy- 

 siognomical character of sex. Desault's mode 

 of laryngotomy consists in a vertical division 

 of this angle from below upward, and has the 

 recommendations of easy performance and of 

 efficiency for the extraction of a foreign body. 

 That it invades parts of high functional endow- 

 ment and extreme irritability, that ossification 

 of the cartilage may unexpectedly prevent its 

 completion, that perfect reunion of the di- 

 vided structure is uncertain are alleged as 

 objections to it, and perhaps over-estimated 

 as such ; for to the first may be answered, that 

 the operation is of relief, and hence little 

 likely to aggravate an irritation, the cause of 

 which it removes ; to the second may be con- 

 ceded, that the mode of operation is not eligible 

 for cases likely to present the bony deposit 

 referred to ; and against the third may be ad- 

 duced the evidence of the French surgeons, 

 by whom chiefly the operation has been per- 

 formed, that the parts are as quickly repaired, 

 and their functions as completely recovered, as 

 after any other mode of operative procedure. 

 As regards its anatomy, nothing can be easier 

 than to lay bare the pomum Adami; a division 

 of the skin, of the superficial and proper fasciae, 

 with some lateral displacement of the sub-hyoid 

 muscles, will suffice for its exposure : and, for 

 its division, the closest following of the me- 

 dial line, in order that the knife may pass be- 

 tween the vocal ligaments, leaving both unin- 

 jured, is the chief precaution to be observed. 

 The upper edge of the glottis is on a level just 

 below that of the superior thyroid notch. The 

 prominence of the thyroid cartilage and the 

 unyielding support which the borders of its 

 arched surface receive from the bony column 

 behind it, render it liable to be crushed by any 

 considerable, direct, antero-poslerior violence. 

 Such has, more than once, been the cause of 

 immediate death where a straightforward blow 

 has reached the larynx in prize-fighting ; and 

 such, too, is a not infrequent effect in death by 

 hanging, especially where, as in the English 

 mode of judicial execution, the rope is made 

 to tighten itself jerkingly. The thyroid carti- 

 lage is sometimes partially divided in attempts 

 at self-destruction, which it commonly frus- 

 trates by defending more important parts. 

 3. A depression which answers to the crico-thy- 

 roid ligament : it is here that the usual opera- 

 tion for urgent glottic dyspnrea is performed. 

 The common integuments and the fascial raphe 



* Medecine Operatoire, 1840, p. 517. 



cover the little interspace in question, which is 

 safely reached between the crico-thyroidei 

 by displacing in a slight extent the sub-hyoid 

 muscles. It has about half an inch of trans- 

 verse breadth, and about a third of an inch of 

 height, is bounded by the inferior thyroid 

 notch and by the anterior part of the circum- 

 ference of the cricoid cartilage ; which borders 

 give attachment to the strong yellow elastic 

 membrane that closes the space. This depres- 

 sion is so readily felt through the integuments 

 its boundaries are so definite and its relations 

 so simple, as to render it a peculiarly eligible 

 spot for bronchotomy, when suddenly and ur- 

 gently required. A small artery sometimes 

 forms, with its fellow of the opposite side, a 

 transverse communication across this mem- 

 brane, and its presence has been much insisted 

 on as a circumstance of practical importance : 

 it is of extreme minuteness, and by no means 

 constantly present : it is the crico-thyroid, and 

 arises from the thyroid branch of the external 

 carotid, near the upper angle of the thyroid 

 body, and runs across the membrane toward 

 the median line. The necessity for haste is 

 commonly of too urgent a character to admit of 

 any deliberate, layer-by-layer, dissective opera- 

 tion : a single steady puncture with a canulated 

 trocar, or with a bistoury directly followed by a 

 tube is the usual mode of conducting it. In 

 such instances the minute artery can hardly be 

 avoided with certainty, but neither can its 

 division be injurious, since the closely fitting 

 canula will secure the cavity of the air-tube 

 against its trifling hemorrhage. In the rarer 

 cases, where time is allowed for a slower divi- 

 sion of the tissues, it would be desirable not to 

 puncture the membrane till the artery, if pre- 

 sent, had been disposed of. It usually lies 

 near to the border of the cricoid cartilage, and 

 might easily be drawn downward away from 

 injury; or its division might be rendered harm- 

 less by torsion, or by a fine ligature. In the 

 more extemporaneous mode of laryngotomy the 

 bistoury should be guided flatly, close beneath 

 the thyroid cartilage; in so making a transverse 

 division of the membrane, it is parallel to the 

 line of the artery, but above its usual position. 

 4. The slight prominence of the cricoid car- 

 tilage, and the series of tracheal rings be- 

 coming progressively deeper toward the ster- 

 nuin, are next felt. In some subjects their 

 chain is seemingly interrupted by a transverse 

 fleshy eminence (which, however, is in health 

 generally imperceptible through the skin), 

 the isthmus of the thyroid gland. To the la- 

 teral portions of this body I shall presently 

 return : the isthmus is its only part having re- 

 lations in the median line, which it crosses to 

 a very variable extent. Most frequently it 

 measures about half an inch in breadth, and 

 corresponds by its middle to the second ring 

 of the trachea : but from this, its normal ex- 

 tent may vary on the one hand to the ex- 

 treme of entire absence on the other to that 

 of being an uncontracted, flattened union 

 of the lateral lobes, which it may so equal in its 

 vertical dimension. Downward from its lower 

 edge, in front of the remaining rings of (he 



