Tracheal agenesis: A case report and review of the literature JOSEPH KERSCHNER,MD, and DOUGLAS W. KLOTCH,MD, FACS,Tampa, Florida Tracheal agenesis is a devastating congenital anomaly first described in 1900 by Payne. 1 In 1962 Floyd et al.2 classified tracheal agenesis into three types (Figs. 1, 2, and 3). One year later, Fonkalsrud et al. 3 attempted the first surgical correction of this anomaly. This attempt, as well as other interventions, have been unsuccessful in allowing any long-term survival. Eighty-seven cases have previously been identified in the world literature. This additional Floyd type III case typifies the problems of assessment and management of this fatal anomaly. A discussion of the embryology and associated congenital anomalies is presented. The clinical aspects of managing this abnormality are described along with previous attempts at surgical correction. Newer investigations may lead to a solution of this lethal anomaly. CASE REPORT A full-term, 3300-gm girl was delivered by normal spontaneous vaginal delivery to a 23-year-old gravida 2, para 1 mother who had an uncomplicated pregnancy with a normalappearing ultrasound at 20 weeks. After delivery the child was noted to have respiratory distress with Apgar scores of 3 and 6 at 1 and 5 minutes. The infant was noted to have an absent cry. Attempt was made to intubate the infant without success. Saturations were maintained with the use of bag-valve mask. Attempts at intubation by the neonatology service were also unsuccessful, and the child was taken to the neonatal intensive care unit while being supported by bag and mask. The ototaryngology service was called, and after direct laryngoscopy revealed no subglottic opening, the infant was taken directly to the operating room. Further endoscopy at this time revealed essentially normal-appearing vocal folds with complete occlusion of the airway immediately in the subglottic area. A patent esophagus was identified posteriorly. A neck exploration was performed in an attempt to identify a tracheal remFrom the Divisions of Otolaryngology(Dr. Kerschner) and Surgery (Dr. Klotch), University of South Florida. Reprint requests: Douglas W. Klotch, MD, Harbourside Medical Towers, 4 Columbia Dr., Suite 730, Tampa, FL 33606. Otolaryngol Head Neck Surg 1997;116:123-8. Copyright © 1997 by the American Academy of OtolaryngologyHead and Neck SurgeryFoundation, Inc. 0194-5998/97/$5.00 + 0 23/4/72278 nant. Only the esophagus could be identified, and intubation of this structure allowed mechanical ventilation with good saturations. A presumed diagnosis of tracheal agenesis was made, and contrast material was used to radiographicatly confirm this (Fig. 4). The child's situation was discussed with the family, who elected no further intervention. The child was returned to the neonatal unit and allowed to die. The family refused a postmortem examination. DISCUSSION Tracheal agenesis is a devastating congenital anomaly that is made even more tragic when it presents in the face of a seemingly normal pregnancy. The diagnosis is now often made antemortem, but the surgeon still has little to offer the child to significantly prolong life. The terms tracheal agenesis, tracheal atresia, and tracheal aplasia have each been used in the literature to refer to essentially the same entity. 4-8 These terms have also been used to differentiate more severe from less severe cases. This fact and the occasional inclusion of severe cases of tracheal stenosis have led to some confusion in the cataloging and reporting of this entity. We evaluated the world literature in an attempt to identify cases not previously included in other reviews. We excluded cases that we believed were not clearly defined examples of tracheal agenesis. Eighty-seven cases of tracheal agenesis were identified in the world literature (Table 1). Some confusion occurs in assigning cases to the Floyd type I category. At presentation cases of Floyd type I have a short segment of distal trachea arising from the anterior esophagus, which then divides into the main-stem bronchi (Fig. 1). Essentially any degree of absent trachea with a concomitant tracheoesophageal communication could technically be classified as a type I tracheal agenesis. Other classification schemes have attempted to further describe and include these variations.33 The classification scheme of Faro et al.33 divides tracheal agenesis into categories A through G, with type A representing total pulmonary agenesis and type G representing tracheal stenosis. Although any pathologic entity will have some degree of variability in severity, it is important to distinguish tracheal agenesis from severe cases of stenosis or a short segment of tracheal atresia. These latter 123 OtolaryngologyH e a d a n d N e c k Surgery 124 Table KERSCHNER a n d KLOTCH J a n u a r y 1997 I. L i t e r a t u r e r e v i e w Case no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19, 20 21 22 23 24 25 26 27-30 31 32-36 37 38 39, 40 41 42 43 44 45 46 47, 48 49 50 51 52, 53 54 55 56 57, 58 59 60 61 62 63 64 65 66 67 68 69 70 Source Payne ~ Beneke 9 Walched ° Fritz ~~ Benesova and Peter 12 MareM 3 Milles and Dorsey TM Kessel and Smith 15 Sandison 16 Hempe117 Devenis and Otis I8 Onarir and Sariyalcin 19 Floyd et al. 2 Fonkalsrud et al. 3 Witzelben 7 McCraken et al 8 Devi and More 21 Stowens 2° Lyons and Bruce 22 Colavecchio 23 Joshi 24 Elmer 25 McNie and PryseDavis 26 Peison et al. 6 Altman et al. 27 Hopkinson 28 Hong et al. 29 Effman et al. 3o Warfel and Schulz 31 Perel et al. 32 Faro et al. 33 Morgan et al. 34 Donovan and Friedman 4 Anderson et al. 35 Buchino et al. 36 Siplovich and Cywes 37 Parameswaran et al. 3s Haupt and Edwards 39 Paes et al. 4o Reilly et al. 41 Solano-Larranga et al. 51 Milstein et al. 43 Evans et al. 44 Haskovcova 45 Sakal et al. 46 Holinger et al. 47 Kearns and Miller 4s Diaz et al. 49 Bray and Lamb 5° Brandenkamp et al. 51 Zimmermann et al. 53 Herbert et al. 54 Ruiz et al. 55 Scurry et al. 56 Rovira et al. 57 Ishii et al. 58 Nakada et al.59 Statz et al. 6o T a b l e 1. L i t e r a t u r e r e v i e w - - c o n t ' d Year 1900 1905 1928 1933 1934 1940 1950 1953 1955 1956 1957 1961 1962 1963 1963 1964 1966 1966 1968 1969 1969 1969 1970 1970 1972 1972 1974 1975 1976 1977 1979 1979 1979 1981 1982 1982 1983 1983 1984 1984 1984 1985 1985 1985 1986 1987 1987 1989 1988 1988 1988 1988 1988 1989 t989 1989 1989 1989 Floyd's type Case no. 71 III II II II III I, II II II 1 III I II II, I, II, I II II, III, II, II, II II II II, II II II I II II III III, II II II III II, II III II II I1,$ II I III II II II III I III II III III Total type l, 11 (~13%); total type II, 53 (-62%); total type III, 22 (~26%). *Case of total pulmonary agenesis with tracheal agenesis. l-Type unclear from translation of article. :t:Second case type not described. 72 73 74 75 76 77 78 79 80-84 85 86 87 88 Source Year Floyd's type ArizmendiDorantes et al. 61 Branger et al. 62 Brichard et al. 63 McDonald and Orio164 Chiu et al. 5 Dost et al. 65 Schiffmann et al. 66 Well 67 Lopaz et al. 68 Koltai and Quiney 6e Rodriguez et al. 7o Downing TM Raso 72 Present case 1989 III 1989 1990 1990 1990 1991 1991 1991 1991 1992 1992 1992 1993 1993 II II III III II II II II II, III, I, I, II III III II Ill examples have a significant portion of healthy trachea, which may allow for survival by prompt surgical intervention. 73 They definitely represent a different clinical entity and likely have a different embryologic genesis as well. It is best to reserve the term tracheal agenesis for cases with a very small, if any, segment of normal distal trachea. These patients cannot be saved by tracheotomy or other surgical intervention at this time. The trachea and esophagus begin their development from the foregut during the third and fourth weeks of gestation. However, the embryology of tracheal stenosis is an unresolved issue. Koltai and Quiney's review of this subject is excellent,69 and they point to at least three competing theories. Initially, most accepted the theory from the works of His, 75 Bremer,76 and Smiths This theory proposed the formation of a tracheoesophageal septum during development. Tracheal agenesis was presumed to result from ventral displacement of this septum. Later work by Zaw-Tun78 and Kluth et al.79 called into question the tracheoesophageal septum. Zaw-Tun claimed that the trachea developed as a ventral outgrowth of the foregut. Kluth et al. showed that the esophagus and trachea develop as the foregut decreases in size by infolding, without formation of a fused septum. The prenatal presentation of infants with tracheal agenesis has ranged from high-risk, complicated pregnancies to completely uneventful ones. One significant prenatal finding in a number of presentations is that polyhydramnios. After delivery, all infants display respiratory distress as well as an absent or exceedingly weak cry. Attempts at intubation will reveal an absent glottic or subglottic opening and an inability to intubate the infant. Some OtolaryngologyHead and Neck Surgery Volume 116 Number 1 KERSCHNERand KLOTCH 125 ,.;.:.., Fig. 2. Type II tracheal agenesis as described by Floyd et al. 2 Fig. 1. Type I tracheal agenesis as described by Floyd et al. 2 confusion may arise by esophageal intubation, which generally allows relatively adequate ventilation in the short term. Stabilization may also be achieved by bagvalve mask. Further respiratory difficulty or suspicion of the diagnosis generally leads to endoscopic evaluation of the infant or emergent neck exploration to identify the trachea and attempt a tracheotomy. Laryngoscopy, bronchoscopy, and esophagoscopy often confirm the diagnosis. Further information can be obtained by a contrast study through the esophagus. Any doubt about the child's anatomy should be confirmed with neck exploration to ensure that a tracheal remnant for tracheostomy does not exist. 49,69 Further management of tracheal agenesis has yielded no long-term survival. Intubation of the esophagus with either an endotracheal or tracheostomy tube provides a temporary airway. Gastric decompression must also be performed to prevent gastric and intestinal dis- tention from the use of the esophagus for ventilation. In type I lesions the short distal tracheal segment may be intubated directly.69 Several attempts have been made to achieve more definitive repair. The first was made by Fonkalsrud et al. in 1963.3 Their attempt involved division of the cervical esophagus. The proximal end provided drainage of oral and pharyngeal secretions, and the distal end was brought out as a stoma and intubated with a tracheostomy tube for ventilation. The chest was ~ e n entered, and distal to the takeoff of the bronchi another division of the esophagus was performed. This procedure allowed separation of the newly created pseudotrachea and the gastrointestinal tract. The distal portion of the second division was used for enteral feedings. Surprisingly, decannulation was apparently successful several days after this procedure. Fonkalsrud's patient survived for 6 weeks, the longest survival period to date. In 1972 Altman et al.27 used a procedure that varied from Fonkalsrud's by performing a gastric division 126 KERSCHNERand KLOTCH OtolaryngologyHead and Neck Surgery January 1997 Fig. 4. X-ray to confirm diagnosis of tracheal agenesis. Fig. 3. Type III tracheal agenesis as described by Floyd et al. 2 instead of dividing the distal esophagus. This procedure provided the theoretical advantage of not having to enter the chest cavity. Other attempts have been made since, using essentially the same principles, and without any significant success.36,57,68 The attempts at surgical correction are hampered by two major factors when the esophagus is used as a pseudotrachea. The first difficulty is that the esophagus lacks rigidity and is therefore prone to collapse with normal inspiratory forces. Second, and more importantly, the esophagus lacks the ciliated respiratory epithelium of the normal trachea. This prevents the efficient handling of secretions and inevitably results in pneumonia, the cause of death in Fonkalsrud's patient. Further management of tracheal agenesis is also complicated by the many other congenital anomalies with which it is often associated. Several investigators noted that cases of tracheal agenesis were frequently accompanied by other defects. 3°,35,4~,43 In 1981 Anderson et al. 35 suggested that tracheal agenesis might be linked to the VATER association. Quan and Smiths0,81 had first proposed the VATER association in 1972. This association included vertebral defects, and atresia, tracheoesophageal fistula and esophageal atresia, radial dysplasia, and renal defects. It was later expanded to VACTERL to include cardiac and limb defects.69.82 Reilly et al.41 and Milstein et al. 43 provided reviews that supported the link between tracheal agenesis and the VATER association. Further investigation by Evans et al. 44 suggested that tracheal agenesis best fit into a new association. This was later termed the TACRD association, and included tracheal agenesis or (laryngo)tracheal atresia, cardiac anomalies, radial ray defects, and duodenal atresia. 44,49How tracheal agenesis is linked to these other nonrandom deformities has yet to be elucidated. Whichever association best includes tracheal agenesis, it is important to realize that any future attempts at dealing with this anomaly will often have other pathologic conditions to address as well. A number of investigators have looked at possible solutions for various tracheal anomalies. Most of the investigations have centered around solving the more common problem of severe or recurrent tracheal stenosis. Various prosthetic materials have been proposed, including Marlex, Dacron, and Silastic,83-85 Both pedicled and free flaps, primarily consisting of periosteal designs, have also been proposed.86-90 Any solution involving replacement of a large portion of the trachea obviously becomes that much more difficult. These potential solutions are plagued with difficulties similar OtolaryngologyHead and Neck Surgery Volume 116 Number I to the use o f the e s o p h a g u s as a trachea. R e c o n s t r u c t i o n m u s t c o n t e n d w i t h the a b s e n c e or i n c o r p o r a t i o n o f resp i r a t o r y e p i t h e l i u m . T h e a i r w a y m u s t b e sufficiently r i g i d to p r e v e n t c o l l a p s e w i t h i n s p i r a t o r y forces a n d m u s t also a d a p t w i t h g r o w t h o f the child. T h e r e is also the difficulty o f g r a n u l a t i o n tissue a n d s t e n o s i s o c c u r r i n g at the suture line o f a n y i n c o r p o r a t e d graft. In 1992 C h o p r a et al.Ss w e r e able to g r o w r e s p i r a t o r y e p i t h e l i u m o n p r o s t h e t i c D a c r o n b y cell culture t e c h n i q u e s . S u c h w o r k will p e r h a p s l e a d to a b e t t e r u n d e r s t a n d i n g o f resp i r a t o r y e p i t h e l i u m a n d a m e t h o d to e f f e c t i v e l y incorp o r a t e it into r e c o n s t r u c t i v e m o d e l s . In addition, r e c e n t a d v a n c e s i n t i s s u e m o l d i n g w i t h m i c r o v a s c u l a r free tissue a n d b o n e i n d u c t i o n m a y h o l d a s o l u t i o n to r e c o n s t r u c t i o n o f l o n g - s e g m e n t t r a c h e a l defects.9~ In s u m m a r y , t r a c h e a l a g e n e s i s is a rare b u t devastating a n o m a l y o f t e n f o u n d i n a s s o c i a t i o n w i t h o t h e r c o n g e n i t a l defects. P r o m p t i n t e r v e n t i o n o f t e n allows for p r e m o r t e m d i a g n o s i s . It is i m p o r t a n t t h a t a n a c c u r a t e d i a g n o s i s b e m a d e a n d t h a t less severe d i s e a s e b e r u l e d out. A l t h o u g h several surgical a t t e m p t s h a v e b e e n m a d e to p r o v i d e a n airway, n o l o n g - t e r m s u c c e s s h a s b e e n a c h i e v e d . It is h o p e d that f u r t h e r i n v e s t i g a t i o n s in trac h e a l r e c o n s t r u c t i o n a n d t r a c h e a l p r o s t h e t i c s will e v e n tually a l l o w t h e s e i n f a n t s a c h a n c e at survival. REFERENCES 1. Payne WA. Congenital absence of the trachea. Brooklyn Med J 1900;14:568. 2. Floyd J, Campbell DC, Dominy DE. Agenesis of the trachea. Am Rev Respir Dis 1962;86:557-60. 3. Fonkalsrud EW, Martete RR, Maloney JV. Surgical treatment of tracheal agenesis. J Thorac Cardiovasc Surg 1963;45:520-5. 4. Donovan TJ, Friedman W. Aplasia of the trachea. Ear Nose Throat J 1979;58:92-9. 5. Chiu T, Cuevas D, Cuevas L, Monteiro C. Tracheal agenesis. South Med J 1990;83:925-30. 6. Peison B, Levitzky E, Sprowls JJ. Tracheo-esophageal fistula associated with tracheal atresia and malformation of tile larynx. J Pediatr Surg 1970;5:464-7. 7. Witzelben CL. Aplasia of trachea. Pediatrics 1963;32:31-5. 8. McCrakert AW, Flanagan N, FlanaganR Tracheal atresia associated with cor biloculare~ Thorax 1964;19:530-2. 9. Beneke R. Uber Bachlunge und Hernia diaphragmatica spuria. Verb Dtsch Ges Pathol 1905;9:202-11. 10. Walcher K. Angeborener Mangel der Trachea. Dtsch Z Gerlichtl Med 1928;12:292-6. l 1. Fritz E. Eine seltene Missbidung der oberen Luftwege. Virchows Arch A 1933;289:264-9. 12. Benesova D, Peter R. Absence of trachea in apparently normal fetus. Cas Lek Cesk 1934;73:356-8. 13. Marek JJ. Congenital deformity of trachea. Ohio State Med J 1940;36:1308. 14. Milles G, Dorsey DB. Intra-uterine respiration-like movements in relation to development of fetal vascular system: discussion of intra-uterine physiology based upon cases of congenital absence of trachea, abnormal vascular development and other anomalies. Am J PathoI 1950;26:411-25. 15. Kessel I, Smith JN. Congenital absence of trachea. Thorax 1953;8:266-8. KERSCHNER and KLOTCH 127 16. Sandison AT. Partial absence of trachea with tive birth. Arch Dis Child 1955;30:475-7. 17. Hempel KJ. Beitrag zur kongenitalen Atresia das Larynx und Aptesie der Trachea. Zentralbl Allg Pathot 1956;95:226-37. 18. Devenis AM, Otis RD. Tracheal atresia associated with tracheoesophageat fistula. J Thorac Surg t957;34:405-8. 19. Onarir R, Sariyalcin B. Yeni dogmns cocukta trabeanin tamamen yokleegu (trachea aplazisi). Tip Fak Mec 1961;24:607-12. 20. Stowens D. Diseases in the respiratory system. In: Pediatric pathology. 2nd ed. Baltimore: Williams and Wilkins. 1966:45281. 21. Devi B, More JRS. Total tracheopulmonary agenesis associated with asplenia, agenesis of the umbilical arteries, and other anomalies. Acta Paediatr Scand 1966;55:107-16. 22. Lyons SM, Bruce AEG. Tracheal agenesis: report on. two cases. Anaesthesia 1968;23:98-102. 23. Colavecchio A. Agenesie der Trachea und LaFynxatresie. Zentralbl Allg Pathot 1968;111:140-52. 24. Joshi VV. Tracheal agenesis. Am J Dis Child 1969;117:341-3. 25. Eimer H. Aplasie der Trachea bei einem Neugeborenen. Zentralbl Gynakol 1969;9!:1614-6. 26. McNie DJM, Pryse-Davies DJ. Tracheal agenesis. Arch Dis Child 1970;45:143-4. 27. Altman RP, Randolph JG, Shearin RB. Tracheal agenesis: recognition and management. J Pediatr Surg 1972;7:i 12-8. 28. Hopkinson JM. Congenital absence of the trachea. J Pathol 1972;107:63-7. 29. Hong SW, Barab GM, Schnaufer L, et al. Tracheal agenesis with bronchoesophageal fistula. Laryngoscope 1974;83:250-4. 30. Effman EL, Sprackman TJ, Bardon WE, et al. Tracheal agenesis. AJR 1975;125:767-87. 31. Warfel DA, Schulz DM. Agenesis of the trachea: report of a case and review of the literature. Arch PathoI Lab Med 1976; 100:3579. 32. Perel A, Kopelovitch J, Ron M, Perlman M. Tracheal agenesis. Harefuah 1977;93:245-6. 33. Faro RS, Goodwin CD, Organ C, et al. Tracheal agenesis. Ann Thorac Surg 1979;28:295-9. 34. Morgan CL, Grossman H, Leonidas J. Roentgenographic findings in a spectrum of uncommon tracheoesophageal anomalies. Clin Radiol 1979;30:353-8. 35. Anderson CL, Ahmed G, CaldweJl CC. Tracheal atresia associated with congenital absence of the radii. CIin Pediatr 1981;20:478-80. 36. Buchino JJ, Meagher DR Cox JA. Tracheal agenesis: a clinical approach. J Pediatr Surg 1982;17:132-7. 37." Siplovich L, Cywes S. Tracheal agenesis. Z Kinderchimrgie 1982;35:12-3. 38. Parameswaran A. Krishnaswami H, Walter A. Congenital bronchoesophageal fistula associated with tracheal agenesis. Thorax 1983;38:551-2. 39. Hanpt PA. Edwards WD. Two cases of tracheal agenesis. Am J Dis Child 1983;137:498-501. 40. Paes BA. de Sa DJ. Hitch DA. Fata malformations of the lar~ r,x and upper trachea. Laryngoscope 1984:94:1477-81. 41. Reilly JS. Adldns JC. Supance JS. Stool SE. Tracheal agenesis: a case report and literature review. Trails Penn Acad Ophthalmol Otolaryngol 1984:37:55-9. 42 Solano-Larranaga H. Coronado-Macias E. Agenesis of ~ e trachea: presentation of a case and review of the literature. Bol Med Hosp Infantil Mex 1984:41:231-3. 43 Milstem MJ. Marcella L. Bickers RG. Tracheal agenesls m infants with VATER association. Am J Dis Child 1985:139:7780. 44. Evans JA. Reggin J. Greenberg C. Tracheal agenesis and associated malformations: a comparison with tracheoesophageal fistula and the VACTERL association. Am J Med Genet 1985:21:2134. 45. Haskovcova I. Agenesis of the trachea: pathologico-anatomic study. Cesk Pediatr I985:40:27-9. 128 KERSCHNER and KLOTCH 46. Sakai N, Makoto I, Miller RH. Temporal bone findings in VATER syndrome. Arch Otolaryngol Head Neck Surg 1986;112:416-9. 47. Holinger LD, Volk MS, Tucker GE Congenital laryngeal anomalies associated with tracheal agenesis. Ann Otol Rhinol Laryngol 1987;96:505-8. 48. Kearns DB, Miller RH. Tracheal agenesis. Int J Pediatr Otorhinolaryngol 1987; 13:143-8. 49. Diaz EM Jr, Adams JM, Hawkins HK, Smith RJH. Tracheal agenesis: a case report and literature review. Arch Otolaryngol Head Neck Surg 1989;115:741-5. 50. Bray RI, Lamb WH. Tracheal stenosis or agenesis in association with tracheo-oesophageal fistula and oesophageal atresia. Anaesthesia 1988;43:654-8. 51. Brandenkamp JK, Maceri DR, Crockett DM. Tracheal agenesis: the importance of an endoscopic diagnosis. Otolaryngol Head Neck Surg 1989;101:688-92. 52. Niranjan V, Daruwalla DR, Shah V, Fernandez AR. Tracheal agenesis. Int J Pediatr 1988;55:635-7. 53. Zimmermann H, Mildenberger H, Kluth D. Tracheal agenesis: which surgical measures are sensible? Z Kinderchirurgie 1988;43:414-6. 54. Herbert M, Kruger-Franke M, Gokel M, Versmold H. Agenesis of the trachea. Pathologe 1988;9:313-7. 55. Ruiz MTE, Ripoll GB, Maluenda CA, Estrany XC. Agenesis of the trachea: apropos a case. Anales Esp Ped 1988;29:185-7. 56. Scurry JR Adamson TM, Cussen LJ. Fetal lung growth in laryngeal atresia and tracheal agenesis. Aust Paediatr J 1989;25:4751. 57. Rovira J, Morales L, Rottermann M, Llaurado VJF, Perez del Pulgar J. Agenesis of the trachea. J Pediatr Surg 1989;24:11267. 58. Ishii K, Hasegawa M, Muraji T, et al. A case of tracheal agenesis. Jpn J Clin Radiol 1989;34:161-3. 59. Nakada K, Kitagawa H, Enami T, Yamate N, Tsukada K, Seki I. Tracheal agenesis with bronchoesophageal fistnlas--a case report. Jpn J Surg 1989;19:494-7. 60. Statz T, Lynch J, Ortmann M, Roth B. Tracheal agenesis: a case report. Eur J Pediatr 1989;t49:203-4. 61. Arizmendi-Dorantes JG, Sanchez-Mendio M, Torres-Castanon R, Rodriquez-Jurado E Agenesis of the trachea. Presentation of a case and review of the literature. Bol Med Hosp Infantil Mex 1989;46:285-8. 62. Branger B, Berlivet M, Wesoluch M, Picherot G, Gerard C, Massias C. Agenesie tracheale. Arch Fr Pediatr 1989;46:359-62. 63. Brichard B, Smeets E, Withofs L, et al. Tracheal agenesis: an exceptional cause of neonatal respiratory distress. Pediatr Pulmonol 1990;9:119-20. 64. McDonald SM, Oriol NE. Tracheal agenesis: resuscitative management. Anesthesiology 1990;73:1279-82. 65. Dost R Majewski F, Roth H, Reckman M, Burrig KF. Tracheal agenesis: a case report. Laryngorhinootologie 1991 ;70:158-60. 66. Schiffmann JH, Rehder H, Speer CR Tracheal agenesis, a rare cause of respiratory insufficiency in newborn infants. Monatsschrift Kinderheilkunde 1991 ;139:102-4. 67. Weil RJ. Pathologic quiz case 1. Tracheal agenesis. Arch Otolaryngol Head Neck Surg 1991;117:804-7. 68. Lopez L, Serrano A, Valera A, Freixinet J, Santa R, Beltra R. Tracheal agenesis: an unresolved problem. Thorac Cardiovasc Surg 1991;39:99-101. 69. Koltai PJ, Quiney R. Tracheal agenesis. Ann Otol Rhinol Laryngol 1992;101:560-6. 70. Rodriguez CC, Alonso EC, Olivera FJT, Losada JP, Reguera CS, De Vargas LD. Total tracheal agenesis. Anales Esp Ped 1992;37:511-3. OtolaryngologyHead and Neck Surgery January 1997 71. Downing GJ. Tracheal agenesis with diaphragmatic hernia. Am J Med Genet 1992;42:85-7. 72. Raso DS. Rare congenital anomaly of tracheal agenesis [Letter]. Ann Otol Rhinol Laryngol 1993;102:971. 73. Sankaran K, Bhagirath CR Bingham WT, Hjertaas R, Haight K. Tracheal atresia, proximal esophageal atresia, and distal tracheoesophageal fistula: report of two cases and review of literature. Pediatrics 1983;71:821-3. 74. His W. Anatomie menschlicher Embryonen. III. Zur Geschichte der Organe. Leipzig: Vogel, 1885:12-9. 75. His W. Zur Bildungsgeschischte der Lungen beim menschlischen Embryo. Arch Anat 1887;19:89-106. 76. Bremer JL Congenital anomalies of the viscera: their embryologic basis. Cambridge, Mass: Harvard University Press, 1957:27-31. 77. Smith EI. The early development of trachea and esophagus in relation to atresia of the esophagus and tracheoesophageal fistula. Contrib Embryo Carnegie Inst 1957;36:41-57. 78. Zaw-Tun HA. The tracheoesophageal septnm--fact or fantasy? Acta Anat 1982;114:21. 79. Kluth D, Steding G, Seidl W. The embryology of foregut malformations. J Pediatr Surg 1987;22:389-93. 80. Quan L, Smith DW. The VATER association: vertebral defects and atresia, tracheoesophageal fistula with esophageal atresia, radial dysplasia. Birth Defects t972;8:75-8. 81. Quan L, Smith DW. The VATER association: vertebral defects, and atresia, T-E fistula with esophageal atresia, radial and renal dysplasia: a spectrum of associated defects. Pediatrics 1973;82:104-7. 82. Khoury MJ, Cordero JF, Greenberg F, James LM, Erickson JD. A population study of the VACTERL association: evidence for its etiologic heterogeneity. Pediatrics 1983;71:815-20. 83. Borrie J, Redshaw NR, Dobbinson TL. Silastic tracheal bifurcation prosthesis with subterminal Dacron suture cuffs. J Thorac Cardiovasc Surg 1973;65:956-62. 84. Neville WE, Bolanowski PJR Soltanzadek H. Prosthetic reconstruction of the trachea and carina. J Thorac Cardiovasc Surg 1976;72:525-38. 85. Chopra DR Kern RC, Mathieu PA, Jacobs JR. Successful in vitro growth of human respiratory epithelium on a tracheal prosthesis. Laryngoscope 1992;102:528-32. 86. Cohen RC, Filler RM, Konuma K, Bahoric A, Kent G, Smith C. The successful reconstruction of thoracic tracheal defects with free periosteal grafts. J Pediatr Surg 1985;20:852-8. 87. Krespi YP, Biller HE Baek SM. Tracheal reconstruction with a pleuroperiosteal flap. Otolaryngol Head Neck Surg 1983;91:610-4. 88. Friedman M, Grybauskas V, Toriumi DM, Kaplan A, Seiden A. Reconstruction of the subglottic larynx with a myoperiosteal flap: clinical and experimental study. Head Neck Surg 1986;8:287-95. 89." Kambic V, Godina M, Zupevc A. Epithelialized microvascular iliac crest flap for reconstruction of a subglottic and tracheal stenosis: a preliminary report. Am J Otolaryngol 1986;7:157-62. 90. Hartig GK, Esclamado RM, Telian SA. Comparison of the chondrogenic potential of free and vascularized perichondrium in the airway. Ann Otol Rhinol Laryngol 1994;103:9-15. 91. Fayad J, Kuriloff DB. Prefabricated microvascular autograft in tracheal reconstruction. Otolaryngol Head Neck Surg 1994;111:396-406.