Bilateral subglottic cysts in an infant treated with C[O.sub.2] laser marsupialization.

We evaluated a 5-month-old girl who had been born at 27 weeks of gestation. During her neonatal period, she had experienced chronic lung disease that necessitated 3 weeks of endotracheal intubation. At 3 months of age, she developed progressive biphasic stridor. Flexible bronchoscopy performed by the pulmonology service suggested a possible subglottic stenosis. The patient was referred to the otolaryngology clinic.

Direct laryngoscopy and bronchoscopy under general anesthesia confirmed the presence of bilateral subglottic cysts. The cysts had obstructed approximately 50% of the airway (figure, A). During this examination, the left-sided cyst was decompressed by simply passing the bronchoscope into the trachea; the cyst ruptured, and mucoid drainage emanated from the cyst wall (figure, B). Afterward, the patient was taken to the intensive care unit and maintained on steroid therapy.

[FIGURES A-B OMITTED]

Following discharge, the patient was followed in the outpatient clinic. Her symptoms subsided initially, but they gradually returned after 4 weeks. Repeat endoscopy approximately 6 weeks after the initial diagnostic procedure revealed a slight recurrence of the left-sided cyst and persistence of the fight-sided cyst (figure, C). Both cysts were marsupialized with a C[O.sub.2] laser (figure, D). The patient's symptoms resolved immediately and remained so at the 4-month follow-up. Repeat endoscopy had been planned at the 6-month mark, but the patient was lost to follow-up.

[FIGURES C-D OMITTED]

This case illustrates the importance of establishing a proper diagnosis in children with signs and symptoms of upper airway obstruction. It also highlights the successful management of subglottic cysts endoscopically with the C[O.sub.2] laser. Bilateral subglottic cysts represent an unusual cause of stridor in the neonatal and infant population. They are believed to be retention cysts that developed from either congenital or acquired occlusion of the subepithelial mucosal glands.

The most common cause of acquired mucosal glandular occlusion is endotracheal intubation. Endotracheal intubation is associated with subglottic cysts independently of both the duration of intubation and the size of the endotracheal tube. The cysts preferentially arise from the posterior subglottis. Typically, the overlying mucosa remains intact and without evidence of friability. Preterm infants are believed to be more susceptible to the development of subglottic cysts because of a variety of factors, including a narrow airway diameter and a frequent need for respiratory support. The prevalence of subglottic cysts seems to be increasing, perhaps as a result of increased preterm infant survival and better recognition of the condition. (1,2)

Various management methods have been described; among them are simple decompression with rigid instrumentation, excision with cup forceps, and marsupialization. (3) Laser marsupialization allows for precise tissue destruction with minimal postoperative edema.

It is well established that simple rupture is associated with recurrence, as occurred in the case described here. Many authors recommend a staged repair to avoid the formation of circumferential scar tissue.

A diagnosis of subglottic cyst should be considered in all children with stridor and a history of endotracheal intubation, regardless of its duration.

References

(1.) Lim J, Hellier W, Harcourt J, et al. Subglottic cysts: The Great Ormond Street experience. Int J Pediatr Otorhinolaryngol 2003;67: 461-5.

(2.) Tierney PA, Francis I, Morrison GA. Acquired subglottic cysts in the low birth weight, pre-term infant. J Laryngol Otol 1997;111: 478-81.

(3.) Smith JD, Cotton R, Meyer CM III. Subglottic cysts in the premature infant. Arch Otolaryngol Head Neck Surg 1990; 116:479-82.

Soham Roy, MD, FAAP; Joseph Zito, MD.

From the Division of Pediatric Otolaryngology--Head and Neck Surgery, University of Miami School of Medicine.