Talk:Paper - Three cases of malformation of the tracheo-oesophageal septum (1906)

From Embryology

Three Cases Of Malformation Of The Tracheo-Œsophageal Septum!: By ARTHUR KEITH, MD, and J. E. Sricek, M.B.

SIR MORELL MACKENZIE, in his Manual of Diseases of the Throut and Nose (vol. ïi. p. 216, 1884), gives a summary of sixty-three cases of malformation of the œsophagus of which only one had been seen by himself, and mentions as à remarkable fact that Hirschsprung had four cases brought to him in à period of six months. The three specimens which are described here came into our possession since July of last year, two in the London Hospital, in cases which were under the care of Dr Percy Kidd, and one of which occurred in the practice of Dr G. H. Harvey of Peckham. But we do not record these cases here because of their rarity, but because, in the first place, the nature of these malformations is not generally understood by those who describe them in the medical press ; secondly, because in all three cases there was present à right aortic arch or its representative— namely, à right subclavian artery arising as the last trunk from the aortic arch; and thirdly, because such records as are to be found in literature are usually not accompanied by illustrations which fully explain the condition. Reference to the valuable “ Reports on Recent Teratological Literature ? published in this Journal by Professor Windle, justities us in believing that the nature of these œæsophageal malformations has not received much attention in late years. A convenient summary of the present state of our knowledge regarding malformation. of the œæsophagus will be found in Dr J. W. Ballantyne’s Antenatal Pathology, vol. ü. p. 462, 1904.

JASE À (see fig. A)—A male, full-time child, who lived a few hours. The œsophagus, at the junction of the upper two thirds and lower third of the trachea, terminated in à dilated cul-de-sac. The lower part of the æsophagus opened from the dorsal aspect of the bifurcation of the trachea, so that its inusculature was continuous with that of the trachea and bronchi. There was a right aortic arch (fig. A); the left subclavian arising last from the arch of the aorta and passing behind the trachea, just below the eul-de-sac of the œsophagus, thus reached the left arm. The left inferior laryngeal nerve passed straight to the larynx. Hare-lip and cleft

1 Read before the Anatomical Society of Great Britain and Ireland, March 1906. Three Cases- of Malformation of the Tracheo-Œsophageal Septum 53

palate were present. There was a wide interventricular foramen due to non-fusion of the endocardial cushions. Family history not obtained.

Case B (fig. B).—A boy, lived six days. No other malformation was observed at the post-mortem examination. A right aortic arch was present with the left subclavian, arising as in case A. The upper segment of the «æsophagus formed à widely dilated diverticulum, and reached to the bifur- cation of the trachea. The lower segment of the œsophagus opened in the posterior wall of the trachea at the junction of the middle and lower thirds

N N

{ UN CA


of that channel. Its orifice was bounded below (see fig. B) by a crescentic fold, the lateral margins of which turned upwards over the free ends of the tracheal rings. The cul-de-sue of the upper segment of the œæsophagus overlapped the origin of the lower segment, to which it was joined by à strand of muscular tissue. Only meconium was passed per anum. Milk was vomited at once, and was blood-stained. The family history showed that the parents and their other six children were normally developed. Case C (see fig. C).—A well-developed child, female, lived nine days. The condition was similar to case B, with the exception that the arch of the 54 Dr Arthur Keith and Mr J. E. Spicer

aorta crossed the left bronchus and gave off the right subelavian artery as its last branch. As in the last case, the subclavian artery lay in the cleft between the upper and lower segments of the œæsophagus. Two supernumerary auricles occurred near the right ear. Hair on scalp long and black. Bullæ on upper part of trunk. Congenital syphilis(?) Vomited immediately on taking food. Vomit blood-stained. Passed meconium and urine. Parents and their three children normally formed. We are indebted to Dr Percy Kidd for permission to examine and report on cases B and C.

The normal formation of the tracheo-œæsophageal septum is clearly shown in the embryological models and publications of His. At the end of the third week (embryo 3:22 mm.) the floor of anterior part of the primitive œsophagus is depressed or evaginated, so that in this segment of the foregut one may recognise a dorsal or œsophageal and a ventral or tracheal division which are separated by lateral ridges which meet behind in à crescentic fold. From the posterior or caudal end of the tracheal division, under the crescentic fold, arise the lung buds. By the end of the fifth week (embryo 12:5 mm. long) the crescentic fold has spread forwards, uniting the lateral ridges, so that the tracheal and æsophageal divisions of the foregut become completely separated from each other by the formation of the tracheo-æsophageal septum. The interarytenoïd fold represents the anterior end of the septum (see fig. D).

To produce the malformations described here, the tracheo-æsophageal septum is evidently formed in the manner shown in fig. E; the lateral tracheo-æsophageal ridges and fold, instead of proceeding horizontally backwards so as to meet between the lung buds and œæsophagus, and so divide the primitive œsophagus into a dorsal and ventral division, proceed obliquely backwards and dorsalwards so as to meet on the dorsal wall of the foregut (see fig. E). In case A, where the œsophagus continues backwards in the line of the trachea, this apparently has been the case, but in the commoner forms shown in B and C (see figs.) it is evident that the tracheo-sophageal septum must have been formed in two parts. The partition between the lower segment of the œsophagus and trachea (see fig. E, «) represents the posterior part of the normal septum, while b represents the anterior part of the septum formed by the obliquely situated tracheo- œsophageal ridges. Morell Mackenzie cites three cases in which the lower segment of the œsophagus opened from a bronchus, from which fact we conclude that the trachea and bronchi (right and left) are derived directly from the foregut by à subdivision of that channel into a dorsal and ventral division by the formation of the tracheo-æsophageal septum, and that only the lungs and intrapulmonary bronchi are formed by à process of out- budding. Three Cases of Malformation of the Tracheo-Œsophageal Septum 55

The fistulæ which are occasionally found between the œsophagus and trachea are apparently due to a partial failure in the union of the lateral ridges which normally unite to form the tracheo-æsophageal septum.

Since recording the above cases we have had an opportunity of examin- ing a fourth. In this case there was no representative of a right aortic arch ; there was atresia ani and malformation of heart.

EXPLANATION OF FIGURE.

A. The œsophagus, pharynx, trachea, and arch of the aorta of case A seen from behind.

B. The same parts of case B, seen from the front, with the trachea opened to show the œsophageal orifice.

C. The same parts in case C, shown in section from the side.

D. Diagram to explain the normal position and relationships of the tracheo- œsophageal septum. The septum is stippled.

E. Diagram to explain the abnormal position of the tracheo-Ͼsophageal septum.

(1) Upper segment of œsophagus ending in a cul-de-sac. (2) Lower segment of œsophagus.

(3) Left bronchus.

(4) Right bronchus.

(5) Arch of aorta.

(6’, 6”) Left and right vagus nerves.

(7) Subclavian artery.

(8) Tracheal orifice of lower segment of œsophagus.

(9) Tracheo-æsophageal septum.