LARYNGEAL WEB

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    LARYNGEAL WEB

     

    DEFINITION:

    A congenital disorder of the larynx characterized by congenital stridor in infancy and hoarseness in childhood.

    EPIDEMIOLOGY:

    • incidence: 5% of congenital laryngeal abnormalities
    • age of onset:
      • newborn (stridor) -> childhood (hoarseness)
    • risk factors:
      • sporadic
      • M = F

    PATHOGENESIS:

    1. Background

    • differentiation of the larynx occurs between 4-10 weeks of gestation

    2. Etiology

    • considered to be a developmental abnormality occurring between the 4-10th week of gestation where the epitheilial fusion between two sides of the larynx fails to dissolve resulting in incomplete recannulization of the primitive larynx
    • 75% of congenital laryngeal webs are present at birth

    3. Types

    • based on the degree of occlusion of the lumen

    1. Type 1

    • 35% covering the anterior glottis

    2. Type 2

    • 35-50% occlusion of the lumen with the vocal cords visible

    3. Type 3

    • 50-70% occlusion of the lumen with the vocal cords posssibly visualized
    • most common type

    4. Type 4

    • 75-90% occlusion with vocal cords not visualized

    CLINICAL FEATURES:

    1. Infancy

    • inspiratory and expiratory stridor +/- upper airway obstruction with respiratory distress
    • paroxysmal dyspnea +/- cyanosis
    • aphonia, weak or feeble cry
    • poor feeding +/- failure to thrive

    2. Childhood

    • hoarseness, weak high-pitched voice, easy tiring of voice
    • recurrent respiratory tract infections
    • chronic cough
    • dyspnea on exertion

    3. Associated Findings (in 10-15% of cases)

    • respiratory tract anomalies
    • cardiac anomalies - ToF, VSD

    INVESTIGATIONS:

    1. Direct Laryngoscopy/Bronchoscopy

    • diagnostic
    • 98% are anterior and 2% posterior
    • location
      • 75% - glottic
      • 12.5% - supraglottic
      • 12.5% - subglottic

    MANAGEMENT:

    1. Supportive

    • respiratory support with severe or life-threatening upper airway obstruction, i.e, intubation, tracheostomy

    2. Surgery

    1. Resection

    • scissors, CO2 laser, radiofrequency current
      • may need repeated dilation with bougienge to prevent reformation of the web by scarring
    • external laryngofissure +/- intralaryngeal shunts or keels to prevent restenosis
    • no resection may be necessary for small webs

    3. Prognosis

    • normal life span
    • may have a prolonged hoarseness of voice

     

     

    Pediatric Database - LARYNGEAL WEB

    Pediatric Organization - Pedbase [at] Gmail.com