332 Congenital laryngomalacia Michael R.N. Baxter Bse MB Cha FRCA

There is at present, very little information on congenital la- d~veloppement du sont d~crits avec une discussion de ryngomalacia in the anaesthetic literature. The purpose of this la physiopathologie et de lhistoire du d~sordre. On pr~sente article is to review this topic, which in 90% of patients represents $galement le diagnostic et un r~um$ des diffHents traitements. a benign self-limiting condition, disappearing by the age of two Autant la ddmarehe anesth~sique que la technique chirurgieale to five years. However, if untreated, the remaining 10% of cases sont controversdes. Notre technique de diagnostic et de r~pa- can prove fatal. This severe form presents as persistent sternal ration ddfinitive est bas~e sur une laryngoscopie en suspension recession, feeding difficulties, and failure to thrive, progressing r~alis~e sous analg$sie locale et ventilation spontan~e. L~alo- to apnoeic attacks, cor pulmonale and eventually death. The thane est ensuite administr~ par insufflation pharyng~e h l'aide developmental and functional anatomy of the larynx will be d'un catheter nosopharyngd n o 8 et une succion est appliqude included, with a discussion of the pathophysiology and history la bouche. Au cours de la r~paration chirurgicale, un of the disorder. Its diagnosis and a rdsumd of the various treat- tube endotrach~al peut $tre ins$r$ h la discretion de l'a- ment strategies, will be presented. The anaesthetic management nesthdsiste et du chirurgien. Finalement, le r6le du laser is controversial as is the surgical technology. Our technique, au CO 2 et ses risques sont ~voqu~s. for diagnosis or definitive repair, is based upon suspension lar- yngoscopy using topical local analgesia and spontaneous yen. tilation. Halothane is then administered by insufflation into Congenital Laryngomalacia (CLM) is the most frequent the , using a #8 nasopharyngeal catheter, and suction cause of in children. It is the most common con- is applied to the mouth. During the surgical repair, an endo- genital abnormality of the larynx, of unknown aetiology. 1 tracheal tube (ETT), may be insertea~ at the discretion of the Other common intrinsic congenital anomalies causing air- anaesthetist and surgeon. Finally, the role of the carbon dioxide way compromise in infants include , man- C02 laser and its hazards will be introduced. dibular hypoplasia, vocal cord paralysis and congenital . Jusqu~ present, la litt~ratum ane~th~sique donne trbs peu d~n- formation sur la laryngomalacie congdnitale. Le propos de vet Embryology of the larynx article est de revoir ce sujet, qui dans 900/0 des cos est b~nin The primary function of the larynx is to provide a pro- et dispara~t vers l'~ge de 2 fi 5 ans. Cependant, les 10% des tective sphincter at the entrance to the air passages; pho- cos restant peuvent devenir I~thanx sfls ne sore pas trait~s. nation is therefore of secondary importance. Cette forme grave se manifeste par un enfoncement sternal per- The larynx starts to appear in the 4 mm embryo at sistant, des difficult~s d'alimentation et un retard de croissance. four weeks. It develops at the eephalad end of the la- Elle s'aggrave de crises apn$iques, de coeur pulmonaire et ~ven- ryngotracheal groove from branchial arches III to VI: tuellement il y a d~cbs. L'anatomie fonctionnelle ainsi que le The laryngotracheal groove is a longitudinal, ventral out- growth of the foregut. By five weeks the arytenoid swell- ings arise and grow cephalad producing a T-shaped glot- tis, reducing the laryngeal lumen to a slit. At six weeks the is forming from branchial arches III and IV. By eight weeks all the major cartilages are present, Key words and at nine weeks the laryngeal aditus enlarges and re- ANATOMY: larynx; canalizes. The false and true appear at ten ANAESTHESIA: paediatric; weeks and by 28 weeks the definitive configuration is ANAESTHETIC TECHNIQUES: insufflalion; present (Figure 1). EQU[PMENT: lasers; SURGERY; laser, carbon dioxide: microinsLrumentation. Anatomy of the larynx From the Department of Anaesthesia, Children's Hospital of The larynx extends from the superior tip of the epiglottis, Eastern Ontario, 401 Smyth Rd, Ottawa, Ontario K1H 8LI. which is narrower in infants and children than in adults, Address correspondence to: Dr. Baxter. to the inferior border of the ericoid cartilage. The cficoid Accepted for publication 11th December, 1993. is the only complete cartilaginous ring in the respiratory

CAN J ANAESTH 1994 / 41:4 / pp 332-9 Baxter: CONGENITAL LARYNGOMALACIA 333

FIGURE 2 Posteriorview of the laryngealcartilages.

back of the epiglottis. The epiglottis is also capable of FIGURE 1 Embryologyof the larynx. Four stages in the rolling posteriorly by the action of the paired thyroepi- development of the larynx, whichiz formedfrom branchialarches glottis muscles. III-VI. The laryngotrachealgroove appears in the floor of the pharynx in the 4 mm embryoat four weeksof gestation, and continuesto develop over the next six months,until lhe fetusis 28 wk (seven Pathophysiology of CLM months).(Reproduced, with pernussion,from CorlissCE, 19762) Anatomically, in addition to the presence of redundant supraglottie mucosa, six mechanisms of CLM have been reported. The fast three are the most commonly seen tract and forms the foundation of the larynx. The cricoid (Figure 3, Table I). is also the narrowest part of the infant larynx. The rima Neuromuscular and/or cartilaginous defects or imma- glottidis is higher in the newborn being opposite the C3~ turity are thought to contribute to this disorder. However, interspace, descending to the adult level of the C4_5 in- no specific association has been confu-med with CLM terspace at 12 years. In addition, the glottis is angled in the recent literature. 5,7 antero-inferiorly, rather than horizontally as in adults.4 As the aetiology of these mechanisms is undetermined, The framework consists of cartilages and membranes, the term laryngomalacia is inaccurate (Greek: malakia which are partly ossified. There are nine cartilages, three = sot~ening). single and three paired. The single cartilages are the epi- glottic, thyroid, and erieoid cartilages. The paired ear- History tilages are the arytenoids, cornicdates and cuneiforms. The condition has been recognized for many years (Table The thyroid cartilage forms the shield of the larynx. The II). inferior horns of the thyroid, and the arytenoids articulate with the erieoid (Figure 2). Severe congenital laryngomalacia - clinical features The superior opening of the larynx is bound anteriorly by the epiglottis, laterally by the aryepiglottic folds, and Stridor (Table 111) posteriorly by the arytennids. In this way, the sphincter In one study, i stridor presenting secondary to congenital of the aditus is formed. laryngeal malformation was reported to be due to CLM The sphincter operates by contraction of the aryepi- in 59.8% of eases. Its onset is usually in the neonatal glottic muscles, drawing the arytenoids anteriorly to the period.14 The stridor is high pitched in nature and in- 334 CANADIAN JOURNAL OF ANAESTHESIA

TABLE I Anatomical mechanisms of upper in CLMS.S

Type 1. The cuneiforms are drawn inwards during inspiration. Type 2. A long tubular epiglottis (~xaggeratedomega shaped f/), curls on itself. Type 3. The arytenoids collapse inwards. Type 4. The epiglottis is displaced against the posterior pharyngeal wall or vocal folds. Type 5. Short aryepiglotticfolds. Type 6. Overly acute angle of the epiglottis at the laryngeal inlet.

TABLE II Historical view of CLMs,7

1853. First description of enngcnital strider,s 1897. First review and description of supraglottic collapse.9 1900. Respiratory incoordination postulated as cause. I~ 1942. Laryngomalaeia, term first used by Jackson and Jackson (malakia the Greek for the morbid softening of an organ).lJ

FIGURE 3 The three most common anatomical abnormalities of TABLE III Chronological steps in the description of Strider in congenital laryngemalacia. All three variations may coexist during the CLM7 relativelynegative pressure created during inspiration. Although not described below, the aryepiglottic folds also prolapse inferio-medially, 1897. Usunlly'presentat birth, intermittent, positional, worse on following the cartilages. Figures A, B and C, represent 'I~pes l, 2, and activity? 3 respectivelyof upper airway obstruction that have been described in 1953. Precipitated by an URTI.s association with CLM. 'l'2qae1. Anter~-inferiorcollapse of the 1977. May develop only months after birth, n cuneiforms (small arrows). Type 2. The above mechanism (small 1983. May develop weeks after birth? 3 arrows), accompanied by the arytenoids inferiorly. This often occurs in 1984. It is the commonest manifestation of CLM and is association with obstruction by an omega-shapedepiglottis, curling characteristically highpitched, inspiratory with sternal recession about its vertical axis (large arrows). Type 3. The epiglottis may roll and presents at bkth. The latter may lead to a lsectus excavatum posteriorly to form a seal against the posterior pharyngeal wall (large and eventually cor pulmonale. In the mild form the severity arrow), and may even prolapse between the vocal cords. (Reproduced, increases until nine months then reaches a plateau, declines and' with permission from HolJnger& Konior, 1989.5) has usually gone by two years.14 1987. May lead to cor pulmonnle.15 1987. The strider may develop months after birth, is intermittent, positional, being worse in the supine position and on activity.It may even persist into early adolescence?6 spiratory in timing, u7 It is loudest when the child is upset. The strider is also more evident in the supine, relative to the prone position. The positional difference is prob- ably due to the dual effect of the tongue and ex- lion. These infants and children are slow to feed, vomit tension on the supraglottic structures. ~7,~s easily and therefore fail to thrive. The incidence of GER Severe CLM may cause upper airway obstruction, cya- has been reported at 33% in a series of 297 patients, ~7 notic spells, feeding difficulties, failure to thrive, cor pul- and in another series as high as 75%. 5 monale, and developmental delay. Death can occur from either upper airway obstruction or heart failure, s,15,~9,~ Relative incidences of complications The relative incidences of these complications have been Cardiorespiratory failure published in a study (Table IV). The spectrum of signs ranges from nasal flaring to chest retraction, tachypnoea, tachycardia, cyanosis, and finally Definitive Diagnosis of CLM a diminished level of consclousness.7 It is essential to obtain a definitive diagnosis of the cause of strider. Congenital laryngomalacia is responsible in the Feeding di~culties majority, but not in all. Diagnosis is by endoscopy, par- Feeding difl~cultJ.es are a result of gastro-oesophageal re- ticularly , but traeheobronehoscopy should flux (GER), which is secondary to upper airway obstruc- also be considered. Congenital laryngomalacia represents Baxter: CONGENITAL LARYNGOMALACIA 335

TABLE IV Preoperative signs and symptoms of CLM in a series of As GER may be present, failure to ensure an empty 13 patients. 5 stomach can result in leading to Symptom~sign No. ofpatients % a lower infection and . ~7 Pro- longed fasting, apart from having no effect on gastric Stfidor 13 100 volume and pH, may be detrimental to a small patient Feeding difficulty 10 77 We use an NPO period of six hours for solids, and three Failure to thrive 8 62 Obstructive apnoea 8 62 hours for clear fluids. A further measure to achieve the Cyanosis 5 38 desired gastric volume and pH, may be by the use of Gastro-oesophageal reflux 3 23 an H~ antagonist. Cimetidine may be administered, over Cot puimonale 1 8 at least 20 min as an /v infusion in 0.9% saline or 5% dextrose (neonates 10 rag- kg -~. day -~ in divided doses every four to six hours; and for infants and children 20 75% of paediatric laryngeal abnormalities that present rag. kg- i. day -1). for endoscopy, 22 but even when the diagnosis is made, Premedication should be non-sedative. The major in- 27% of patients with CLM have additional airway prob- dication is to block cardiovagal reflexes. An antisiaia- lems. 23 gogue is also an advantage. Indirect laryngoscopy using a mirror is not possible Atropine appears to be the drug of choice and it should in infants and young children. The diagnosis of CLM be administered/v prior to induction of anaesthesia. has therefore to be confirmed by flexible endoscopy using a nasopharyngoscope, or failing this by rigid endoscopy. Induction The latter will require general anaesthesia 24 After placement of monitors, /v access must be estab- Suction placed at the level of the cords will augment fished, if not already secured. Halothane in 100% oxy- inward collapse of the supraglottic structures,25 and assist gen is used for induction. The time taken to reach an in the diagnosis of CLM. This is referred to as a positive adequate depth of anaesthesia will take longer than nor- "Narey sign. "7 This "suction test" may also be used during mal, depending upon the degree of upper airway obstruc- the operation, to detect redundant supraglottic mucosa, tion that is present. However, as anaesthesia is deepened which is removed by microsurgery, employing microin- and a small amount of CPAP (5 cm H20), is applied struments, 7,~4,25 or the CO2 laser. 5'26 to the reservoir bag, the stridor usually disappears. Tiffs The aim of laryngoscopy, is to identify three anatom- makes the airway easier to manage, and therefore in- ical abnormalities that occur either separately or in com- creases the rate of induction. When an adequate depth bination: (1) flaccid epiglottis; (2) poorly supported aryte- of anaesthesia has been reached, a laryngeal spray of noids; (3) short aryepiglottic folds. However, several 4 mg. kg -1 lidocaine, diluted, may be used to obtund problems may hinder the diagnosis of CLM. 23 airway reflexes (each spray = 10 mg). The local anaes- It has been recommended that, in the neonate, the di- thetic is better absorbed by a dry mucosa. Atropine and agnosis should be based on awake flexible endos- lidocaine may also have the additional benefit of delaying copy. s,~8~4.27 However, this may cause cord abduction, as the onset of bradydysrhythmias and tachydysrhythmias, a result of crying, and mask the presence of CLM. 2~ respectively. During suspension laryngoscopy, the laryngoscope blade Spontaneous venti/afion is maintained to assess supra- may splint the vallecula, preventing prolapse of supra- glottic movement, and to avoid the potential problems glottic redundant mucosa, especially that on the epiglottis. that may be associated with other causes of stridor. Ke- The shallow breaths of spontaneous ventilation, during tamine is used by some but may be relatively contraindica- deep inhalational anaesthesia, will also lessen the like- ted, as it has been reported to stimulate and lihood of the inward prolapse of offending mucosa. also to increase oxygen demand by hyperventilation. 2s

General anaesthesia for a def'mitive diagnosis Maintenance of anaesthesia

Preoperativepreparation WITH SUSPENSIONLARYNGOSCOPY In mild cases all that may be required is a history, clinical Anaesthesia may be maintained with topical analgesia examination, complete blood count and electrolytes, with and spontaneous ventilation, with insufllafion into the lateral neck and chest x-rays. An ECG may be ordered pharynx. Spontaneous ventilation without an ETT allows if there are signs of cor pulmonale. Barium studies, chest an unobstructed view of the larynx. It also allows the CT-scan and angiography are reserved for those cases flaccid supraglotfic tissue to prolapse inwards during in- where a vascular anomaly may be present. spiration. After anaesthesia has been established the mask 336 CANADIAN JOURNAL OF ANAESTHESIA is removed and a suspension laryngoscope is introduced. Halothane in 100% oxygen is then insufflated by one of the following methods: (i) directly into the mouth; (ii) by the use of a #8 nasopharyngeal catheter; 26 (iii) a nasal ETT pulled back to the nasopharynx; 27,29 (iv) via the side-arm of the laryngoscope; :9 or (v) with a modified anterior commissure retractor. 3o Of the above choices, the use of a nasopharyngeal cath- eter appears to be the most suitable, and is our practice. It must be borne in mind though, that the anaesthetist does not have complete control of the airway, so that FIGURE 4 Aryepiglottoplasty. A form of supraglottoplasty, in wl'fich excellent communication between the anaesthetist and the redundant mucosa, over the arytenoids and aryepiglottic folds, is surgeon is imperative. excised. The cuneiforms being located within these folds are also In the spontaneously breathing patient, a less popular removed. (Reproduced, with permission, from Jani et aL, 1991.7) technique, due to the movement produced, is Intermittent apnoea. This is achieved by the intermittent removal of TABLE V Developmentsin surgeryfor severeCLM s,7 the facemask or ETT. 31,n The surgeon then has a series of short periods in which to make a diagnosis. 1922. Amputation of the epiglottis?~ When ventilation must be controlled, Insufflation is 1944. Wedge resection of theepiglottisfl still the method of choice. The alternative, jet ventilation, 1971. Epiglottis sutured to the base of the tongue. 42 is not recommended in infants and young children, 1971. Hyomandibulopexy. 43 1984. The first microsurgical endoscopic surgery for CLM) 4 mainly due to the risk of barotrauma. When using the 1985. Longitudinal aryepiglottie folds incision. ~ injector, inspection has to be limited to the times when 1987. Aryepiglottoplasty with gloaso-epiglottopexy. ~ the vocal cords are not abducted and vibrating. This tech- 1989. Laser surgical supraglottoplasty? nique will have the same deleterious effect during 1991. Microinstrumental aryepiglottoplasty. 7 surgery, n-36 Continuous suction of the oropharynx by a catheter, taped to the cheek of the patient, will decrease pollution. 26 Mild laryngomalacia is benign and self-limiting, re- quiring reassurance and follow-up. Severe CLM, how- WITHOUTSUSPENSION LARYNGOSCOPY ever, requires surgical intervention. 14 The procedure becomes more straightforward when a flexible fibreoptic system is used. After an irthalafional Surgical options for severe CLM induction, fibreopfic endoscopy may be performed Before the 1980s the mainstay of management was a tra- through a facemask, using a Portex fibreoptic swivel cheostomy. Today, the use of a tracheostomy has been adaptor between the faeemask and the anaesthesia sys- abandoned due to the high morbidity, 46.5%, and mor- tem; in this way the anaesthetist may have more control. tality, 1.4% to 10%, with which it is associated. ~7-39 The scavenging of waste gases is more efficiently handled The current surgical aim is to perform a type of su- if this method is adopted but it may be suitable only praglottoplasty, i.e., removal of prolapsing redundant su- for older infants and children. praglotfic mucosa: the amount and site of tissue removed varies. The terms epiglottoplasty, supraglottic trimming, Postoperative care anterior epiglottopexy, and aryepigiottoplasty have been Patients should be kept NPO for four hours postopera- used to describe these procedures, depending on what tively and placed in humidified oxygen, in an intensive type of surgery has been performed, s,7,14,15J9 However, care environment for observation of signs of airway ob- the interarytenoid mucosa is never removed, but pre- struction. The signs include: stridor, nasal flaring, dysp- served to prevent postoperative stenotic scarfing (Figure noea, tachypnoea, suprasternal, intercostal or subcostal 4, Table V). indrawing, a low or falling transcutaneous oxygen sat- uration, or a decrease in the level of consciousness. Laser surgery versus microsurgieal instrumentation Raeemic epinephrine and steroids are rarely necessary. Either of these options may be chosen with or without However, the doses are: raeemic epinephrine by faeemask the use of an ETT. However, if the laser is not to be (0.2 ml of 2.25% solution, diluted in 2.5 ml of saline, used, then an oral or nasal ETI" may be placed. It offers nebulised with 100% oxygen, i.e., 2.25 mg), and dex- complete control of the airway, and may even splint the amethasone 1 mg. kg -l. larynx for the surgeon, making his task easier to perform. Baxter: CONGENITAL LARYNGOMALACIA 337

There are then no limitations on the type of anaesthesia immobility, then the Laser-Flex (Mallinkrodt, St Louis, provided, and no scavenging problem. Carbon dioxide MO), is safe to use with the CO2 laser, and does not laser surgery has become popular recently, as it offers require to be wrapped. 48 There is then the option of using some advantages over the use of the conventional mi- a muscle relaxant. crosurgery. Tissue destruction is precise, immediate, and The patient's exposed skin, and particularly eyelids, bloodless and tissue manipulation is unnecessary. The are protected with saline-soaked gauzes. The personnel absence of instruments means that there is an unob- also need protection, particulary by eye wear. Ideally a structed view of the operative field. Healing is faster as team should be formed which performs all the laser cases. there is minimal oedema, pain and scar formation. 4s There should be minimal personnel and movement in However, there is controversy over the operative the room. A laser-linked visible and audible warning in- method used. Some surgeons prefer the feel of the tissue, 7 side and outside the room is recommended. 28 and obtain excellent results with the more traditional tech- nique using microinstrumentation, 25 and feel that at Postoperative care times, it may be preferable to the use of a laser, s Regardless of the treatment modality used, humidified oxygen, racemic epinephrine and dexamethasone may be General anaesthesia for severe CLM required to treat signs of airway obstruction as detailed in the above section on diagnosis. Conventional mierosurgery A supraglottoplasty performed with conventional instru- Why the carbon dioxide laser over other laser media? ments, produces good results in certain centres, ~,7,2s and The CO2 laser is used in preference to other lasers in there is a reticence to change, particularly as new equip- airway surgery because it is invisible, provides an un- ment is expensive and people to work with it must be obstructed view of the surgical field, and is capable of trained. The anaesthetic is simplified in the absence of being focussed down to <2 mm. 45 It is also able to coag- a technique that may result in an airway fire: specific ulate vessels <0.5 mm diam. This precision helps to di- gas mixtures and special ETTs become unnecessary. It minish postoperative pain, oedema, bleeding and scar for- is also easier to assist or ventilate the patient's ~f marion, z9 all of which are critical in the narrow diameter an ETI" is in place. If necessary the patient can also of the paediatric airway. be made immobile with a muscle relaxant. Carbon dioxide laser hazards32 Carbon dioxide laser surgery These include eye damage, bleeding into the airway, air- Some surgeons prefer the use of the CO2 laser, despite way perforation, fire inside the airway or outside, and its implications for the anaesthetist. We use the same an- atmospheric contamination: aesthetic technique, insuffiation, as for diagnosis, as do others 26,27,29 with the additional precautions for laser Eyes surgery. Once the "best" airway is obtained with halo- The eye is the organ most susceptible to damage. 24 Cor- thane in 100% oxygen, the inspired oxygen percentage, neal damage would be the result, but there is no risk FIO2 should be lowered as far as possible by the addition to the retina. The patient's eyes must be protected by of air. If the patient's oxygen saturation starts to decrease, damp gauzes whilst the surgeon's are protected by the the FIO2 increased incrementally until an acceptable level optics of the operating microscope. All other personnel is reached. Should airway obstruction develop, the reflex in the room should wear goggles, 45 as optical spectacles to fill the reservoir bag with the oxygen flush must be do not offer wrap-around protection. suppressed until the surgeon is informed. Volatile anaes- thetics in clinical concentrations are nonflammable and Bleeding and airway perforation may be used with safety. 32 Nitrous oxide is also non- Vessels > 0.5 mm are not coagulable, so bleeding into flammable but supports combustion as easily as oxy- the airway may occur. Laryngeal and tracheal peroration gen at high temperatures, and should not be used. ~9,46 have been reported, as has massive subcutaneous em- Helium does not reduce the risk of fire compared with physema with bilateral pneumothoracies following laryn- air as the carrier gas, but may offer an advantage, because geal laser surgery. 49 of its reduced viscosity and density, in the severely com- promised airway. 47 Atmospheric contamination The absence of an ETT obviates concerns over the Unfortunately, the CO2 laser produces the most smoke type of ETT or protective tape required. However, if an of all the laser media, tissue vaporization producing a ETI" is indicated: for prolonged procedures or complete plume of smoke and fine particles (0.31 p.m). Ordinary 338 CANADIAN JOURNAL OF ANAESTHESIA masks fdtre only to 3.0 ~m, therefore a high efficiency ynx; a Textbook for Students and Practitioners, 2nd ed. mask is required (The Protector 11, Anago, Fort Worth, New York: MacMillan Publishing Co., Inc., 1942: 63-8. Texas). 32 12 McSwiney IF, Cavanagh NPC, Languth B Outcome in congenital stridor (laryngomalaeia). Arch Dis Child 1977; Fire 52: 215-8. The greatest fear is that of an airway fire. Measures must 13 Cotton R, Reilly JS. Congenital malformations of the lar- be taken to minimize the risk of any fire, and to deal ynx. In: Bluestone Ed, Stool SE (Eds.). Pediatric Otolaryn- with the problem should it arise. gology, Vol 2. Philadelphia: WB Saunders Company, 1983: 1215-24. Conclusion 14 Lane RW,, Welder D J, Steinem C, Marin-Padilla M. Congenital laryngomalacia can either be mild or severe. Laryngomalacia: a review and case report of surgical treat- The former only requires investigation and follow-up. Se- ment with resolution of pectus exeavatum. Arch Otolaryn- vere CLM, however, needs a form of supraglottoplasty, gol 1984; 110:546 51. using microinstrumentation or the CO2 laser. When 15 Zalzal GH, Anon JB, Cotton RT. Epiglottoplasty for the surgery is performed, we use a technique, without an treatment of laryngomalacia. Ann Otol Rhinot Laryngol ETT, in order to provide a clear view for the surgeon. 1987; 96: 72-6. However, this is controversial. If laser surgery is chosen 16 Cinnamond MJ Congenital disorders nfthe larynx, tra- by the surgeon, it is important to establish a protocol, chea and bronchi. In: Evans JNG (Ed.). Paediatric Otola- and to develop a team that performs all the surgery in ryngology, 5th ed. London: Butterworths, 1987; 412-9. order to estabish proficiency. 17 Nussbaum E, Maggi JC. Laryngomalacia in children. Chest 1990; 98: 942-4. Acknowledgements 18 Zalzal GH. Stridor and airway compromise. In: Grundfast The author wishes to thank Dr. Elliot Rhine for his val- KM (Ed.). Recent Advances in Pediatric Otolaryngology. uable suggestions and review of the manuscript. I am Philadelphia: WB Sannders Company, 1989: 1389-1402. also indebted to the staff of the Audio-Visual department, 19 Marcus CL, Crockett DM, Davidson Ward SL. at the Children's Hospital of Eastern Ontario (CHEO), Evaluation of epiglottoplasty as treatment for severe laryn- for their technical assistance. gomalacia. J Pediatr 1990; 117: 706- I0. 20 Solomons NB, Prescott CAJ. Laryngomalaeia. A review References and the surgical management for severe cases. Int J Pediatr 1 Holinger LD Etiology of strldor in the neonate, infant and Otorhinolaryngol 1987; 13: 31-9. child. Ann Otol Rhinol Laryngol 1980; 89: 397-400. 21 Guilleminault C, Ariagno RL Fomo LS, Nagel I., Bald- 2 Corliss CE. Patten's Human Embryology. Elements of win R, Owen M. Obstructive sleep apnea and near miss Clinical Development. New York: McGraw-Hill, 1976: for SIDS: 1. Report of an infant with sudden death. Pediat- 298. rics 1979; 63: 837-43. 3 Pansky B. Review of Medical Embryology. New York: 22 Holinger PI-L Brown W77 Congenital webs, cysts, laryngo- MacMillan Publishing Co., Inc., 1982: 150. coeles and other anomalies of the larynx. Ann Otol Rhinol 4 Cotd CJ, Todres I1) The pediatric airway. In: Cot6 CJ, Laryngol 1967; 76: 744-52. Ryan JF, Todres ID, Goudsouzian NG (Eds.). A Practice 23 Gonzalez C, Reilly JS, Bluestone C1) Synchronous air- of Anesthesia for Infants and Children, 2rid ed. Philadel- way lesions in infancy. Ann Otol R.hinol Laryngol 1987; 96: phia: WB Saunders Company, 1993; 55-80. 77-80. 5 Holinger LD, Konior RJ Surgical management of severe 24 Feinstein R, Owens WD. Anesthesia for ear, nose and laryngomalacia. Laryngoscope 1989; 99: 136-42. throat surgery. In: Barash PG, Cullen BE S'toetling RK 6 Apley J. The infant with stridor. A follow-up survey of 80 (Eds.). 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