Bifid epiglottis

Ear, Nose & Throat Journal, Nov, 2007 by Stefanie K. Horne, Peter G. Michaelson, Erik Weitzel

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A 3-year-old boy with a history of autism, polydactyly, and micrognathia was evaluated for snoring, witnessed apneas, and nasal airway obstruction. His medical history included premature birth at 32 weeks' gestation and neonatal stridor and hydronephrosis, both of which resolved spontaneously. There was no recurrence of the stridor, and no cough or aspiration was reported.

On examination, the patient was noted to have small, nonobstructing tonsils in addition to the micrognathia. Flexible endoscopy revealed a 90% obstruction of the choanae secondary to adenoid hypertrophy. Additionally, a bifid epiglottis was noted. Closure of the laryngeal inlet appeared to be adequate during deglutition. Polysomnography was attempted, but the patient did not tolerate it and the attempt was abandoned. A review of a previously obtained magnetic resonance image revealed that the brain

The opinions and assertions expressed in this article are those of the authors and do not necessarily represent the official policy of the U.S. Air Force or the Department of Defense. was normal. The patient's multiple congenital abnormalities corresponded with no known syndrome.

The patient was taken to the operating room for adenoidectomy and diagnostic laryngoscopy and bronchoscopy. During the procedure, bifid epiglottis was confirmed (figure). No other airway abnormalities were identified. The patient tolerated the procedure well, and he experienced significant postoperative alleviation of his snoring and apneas.

Bifid epiglottis--defined as a cleft in the epiglottis of at least two-thirds of its length--is a rare anomaly that is almost always associated with multiple other congenital defects. (1) The most commonly reported associated defects are (1) abnormalities of the digits of the hands and feet, which occur in as many as 90% of patients (polydactyly in as many as 75%), and (2) oral anomalies--including cleft palate, cleft uvula, micrognathia, and microglossia--which occur in as many as 84% of patients. (2) The most devastating associated anomalies are those of the hypothalamic-pituitary axis; they include hypothalamic hamartomas and the absence of a pituitary gland, which can lead to growth retardation, hypoglycemia, hypoadrenalism, and hypothyroidism. (2) Fortunately, hypothalamic-pituitary axis anomalies are rare.

The pattern of associated anomalies supports the hypothesis that bifid epiglottis is the result of a teratogenic event rather than a genetic mutation since the embryologic development of the epiglottis occurs at the same time as that of the hand, hypothalamus, larynx, and oral cavity. (1) A challenge to that theory was provided by the results of a case series by McClay et al, who studied three generations of a family in which 5 of 8 members available for examination had polydactyly and some degree of cleft epiglottis,s As a result, the true etiology behind these anomalies is still unknown.

Reports of bifid epiglottis in the literature are rare. Sturgis and Howell reviewed 12 cases and found that associated congenital abnormalities were commonly seen. (1) Most of those patients presented with airway complaints--stridor, dysphagia, dysphonia, and dyspnea. Two of these patients died during the neonatal period. In only 1 of these 12 cases was the bifid epiglottis discovered as an incidental finding; this occurred during intubation for an unrelated surgery. Our patient was found to have a bifid epiglottis by flexible endoscopy during an evaluation of adenoid hypertrophy.

Multiple theories have been proposed to explain the embryologic origin of the epiglottis. Most authors believe that the midline hypobranchial eminence is the sole precursor of the epiglottis. Contribution from the paired fourth pharyngeal arches to the lateral portion of the epiglottis remains controversial. (1,3) Based on the findings of the 12 cases they reviewed, including the number and location of clefts, Sturgis and Howell theorized that the epiglottis has one medial precursor (the hypobranchial eminence) and two lateral precursors (the paired fourth pharyngeal arches). (1) Such an origin would account for the array of congenital epiglottic abnormalities that are seen, including wide midline clefts (attributable to an absence of the hypobranchial eminence) and paired lateral clefts (secondary to a failure of the hypobranchial eminence to fuse to the lateral fourth arches). It is more difficult to explain these anomalies by citing the theory of one midline epiglottic precursor.

References

(1.) Sturgis EM, Howell LL. Bifid epiglottis syndrome. Int J Pediatr Otorhinolaryngol 1995;33(2):149-57.

(2.) Stroh B, Rimell FL, Mendelson N. Bifid epiglottis. Int J Pediatr Otorhinolaryngol 1999;47(1):81-6.

(3.) McClay JE, Wiatrak B, Proud VK. Bifid epiglottis and polydactyly: A new genetic syndrome. Otolaryngol Head Neck Surg 1997:116(1):129-33.

Stefanie K. Horne, MD; Peter G. Michaelson, MD; Erik Weitzel, MD

From the Department of Otolaryngology--Head and Neck Surgery, Wilford Hall Medical Center, Lackland Air Force Base, Tex.