1. Differential Diagnosis: Infantile Stridor
Amy Stinson
MS IV
KCUMB

2. Stridor
An expression of partial respiratory tract obstruction 2° to external compression or partial occlusion within the airway1
Character & Intensity:
Site & Degree of obstruction
Airflow velocity & Pressure gradient
Stridor

3. Stridor
Inspiratory – problem at or above vocal cords, usually high pitched at cords, low pitched above cords
Laryngomalacia, unilateral cord paralysis
Expiratory – problem is below cords – tracheobronchial tree, more prolonged
Vascular compression
Biphasic – usually subglottic
Subglottic stenosis, subglottic hemangioma, bilateral cord paralysis

4. Laryngomalacia Most common cause of stridor
Most common congenital laryngeal abnormality
“Congenital flaccid larynx” or “Inspiratory laryngeal collapse”
Inspiration:
Prolapse of supraglottic structures
Extreme infolding of “Omega-shaped” epiglottis and aryepiglottic folds
Lateral margins of epiglottis fold inward; aryepiglottic folds are tall, foreshortend and thin; arytenoids are large with redundant tissue. Mucosal edema makes symptoms worse.

5. Laryngomalacia
Photographs show a case of laryngomalacia during expiration (A) and inspiration (B). Note the infolding of the aryepiglottic folds.

6. Laryngomalacia Normal Vs Abnormal

7. Laryngomalacia Signs & symptoms:
Inspiratory stridor within a few days of birth
Initially mild  more pronounced with a peak at 6 –9 mo4
Stridor is worse when supine and neck flexion: better when prone and neck extension1
Symptoms worse when sleeping, feeding, or on exertion
Most commonly – mild stridor that is self limited
Most cases spontaneously resolve by 2 yrs of age

8. Laryngomalacia More Severe: Presumed etiologies:4
Severe stridor, apneic episodes, feeding problems, & FTT
 pulmonary HTN & cor pulmonale
Presumed etiologies:4
Abnormally pliable supraglottic cartilage
Neuromuscular abnormalities
GER

9. Laryngomalacia DX: Treatment: Endoscopy under local anesthesia
Laryngotracheobronchoscopy to R/O other path
Polysomnography to detect desaturations w/hypoxia or hypercapnia
Treatment:
OBSERVE
Temp trach in severe cases
Sx for 10%  supraglottoplasty which reduces amount of laryngeal mucosa
Anti-reflux meds
Supraglottoplasty – divide aryepiglotitc folds, excise wedge of folds with or with out trimming arytenoids on lateral borders of epiglottis, suture epiglottis to base of tongue
Watch out for bleeding, aspiration and supraglottic scarring

10. Laryngomalacia “State Dependent” Laryngomalacia6
Neurogenic factors would cause at states of awareness – often paradoxical.
Direct stimulation resolves
Discoordinate Pharyngolaryngomalacia6
Assoc. with severe collapse and poor outcomes
Need CPAP & nasal stents and poss. trach

11. Vocal Cord Paralysis
Second most common congenital abnormality of larynx4
Congenital & Bilateral is most common presentation with stridor and is usually seen in males4
Unilateral paralysis on Left seems to be more common but less associated with stridor6
Check nucleus ambiguous & supranuclear tracts plus Vagus nerve & branches3

12. Vocal Cord Paralysis Etiology: Idiopathic
CNS: Arnold-Chiari malformation
CV: Congenital abnormalities of heart & great vessels of Sx correction of
Trauma: Repair of TE fistula, birth trauma, head injury
Inflammatory: Guillian-Barre
PNS: myotonic dystrophy, myasthenia gravis

13. Vocal Cord Paralysis Signs & Symptoms:
Asymp  acute airway obstruction
High pitched inspiratory stridor, apnea, cyanosis
Hoarse, breathy cry
Weak cough
All more common with bilateral palsy

14. Vocal Cord Paralysis Dx: Tx: Fiberoptic endoscopy
Laryngotracheobronchoscopy
MRI
Tx:
Unilateral: Observe, Speech therapy
Bilateral: Tracheotomy, frequent endoscopies, no Sx for at least a year – maybe longer
CNS mcc in infancts, cords are usually adducted which can cause airway compromise

15. Vocal Cord Paralysis

16. Subglottic Stenosis 3rd most common congenital cause of stridor
Subglottis is the narrowest part of airway & the only complete ring (cricoid cartilage)
Congenital & Acquired

17. Subglottic Stenosis2,4,5 Congenital: Acquired:
Soft tissue stenosis or cartilaginous stenosis
Severe: stridor at birth
Mild: intermittent stridor & resp tract infections
Acquired:
Neonatal intubations, external trauma, high trach, infection, burns
Repeated failure of attempted extubation
Gradual onset of stridor after extubation
Pressure necrosis of subglottic mucosa, duration of intubation is most determining factor
Edema & ulceration follow  perichondritis  granulation & fibrous tissue formation

18. Subglottic Stenosis1,2
Stenosis if < 4mm in full term infant; < 3mm in preterm infant
Meyer-Cotton Grading
I: 0-50%
II: 51-70%
III: 71-99%
IV: no detectable lumen

19. Subglottic Stenosis Decrease risk: Uncuffed, polyvinylchloride tubes
Smaller tubes
Nasotracheal intubation = less friction
Risks – larynx 1/3 size of adults; arytenoids make up more of the glottis; smaller subglottis; tissue is softer and more pliable

20. Subglottic Stenosis Treatment:
Observe: Grade I, II, airway can increase with growth of child
Tracheotomy: until reconstruction
Endoscopic: Laser can decrease granulation tissue, can actually worsen with long term scarring
Laryngotracheal reconstruction: requires cartilage grafts and stents, enlarges stenosed portion
Cricotracheal resection: excises stenosed portion, higher success rate, but increased risk of recurrent laryngeal nerve damage

21. Subglottic Hemangioma
A soft, compressible, bluish tumor below true vocal cords
Female > male 2:1
50% have cutaneous hemanigioma
Subglottis is most common location – usually unilateral
Tend to proliferate from birth – 1 yr then involute. Usually resolved by 5 yrs.

22. Subglottic Hemangioma
Signs & Symptoms:
Intermittent stridor that progresses to biphasic stridor with dyspnea and cyanosis
Originally dx as croup

23. Subglottic Hemangioma
Treatment
Observe: if small
Tracheotomy until involution
Steroids – possible estrogen receptor  involution
Laser therapy – good for hemostasis
Surgical excision – becoming more common because of stenosis from trach
Interferon – alfa-2a has antiangiogenic activity when hemangioma in proliferate phase
Trach & Laser stenosis
Steroids  HTN Cushings growth retardation
IFN – can get rebound growth and effects in kids not totally known

24. Less Common Causes of Stridor
Dysphagia lusoria
Laryngeal cysts
Congenital laryngeal webs
Laryngeal foreign bodies
Respiratory papillomatosis

25. Dysphagia Lusoria “Dysphagia of unclear etiology”
Congenital anomalies of aortic arch:
Double aortic arch
Anomalous origin of R or L subclavian artery
Kommerell’s Diverticulum – saccular aneurysmal dilation at of ARSA or ALSA
If LA or ductus present between subclavian and pulmonary  complete vascular tracheobronchial ring
Presents as respiratory distress, dysphagia & stridor

26. Dysphagia Lusoria Dx: Tx: CXR Barium swallow w/ esophogram
Sx repair through lateral thoracotomy with lung separation
Embryo – distsal end of interrupted 4th aortic arch btw carotid and subclavian

28. Laryngeal Cysts2,4 Rare cause of Stridor More superficial Fluid filled
Ductal: MC, originate from obstruction of submucous gland
Saccular: in laryngeal ventricles, usually congenital

29. Congenital Laryngeal Webs1,2,4
Embryology: Failure of complete recanalization
Most common in anterior glottis (fusion of ant portion of vocal cords)
Abnormal cry & stridor
Incise thin webs
Excise and stent severe webs

30. Laryngeal Foreign Bodies4
MC in kids 1-3 yrs
Most inhaled objects pass through larynx and lodge distally
If lodged in larynx & partially obstructed
Stridor, hoarseness, and cough
Confirm w/X-ray
Remove in OR

31. Respiratory Papillomatosis1,2,4
Most common neoplasm of larynx in children
Dx: most common btw 2 –5 yrs
Increased risk:
First born, vaginal delivery, teenage mother
HPV 6, 11
Gradual progression of dyspnea and stridor
Tx: surgical ablation w/CO2 laser  webs & scarring
Larynx mc involved, thought to be b/c of amniotic fluid aspiration, can lead to life threatening airway obsruction

32. References
1. Rowe, LD. Pediatric Airway Obstruction. Otolaryngology – Head and Neck Surgery. Current Surgery. Chap 38.
2. Kirby, GS. et al. Respiratory Tract and Mediastinum. Current Pediatrics. Chap 18.
3. Gormley, PK. et al. Congenital vascular anomalies and persistent respiratory symptoms in children. International Pediatric Journal of Otorhinolaryngology. Nov 1999: 51:23-31.
4. Lange, et al. Current Opinion in Otolaryngology and Head and Neck Surgery. Lippincott, Wilkins and Williams. Dec p 349.
5. Mossad, E. et al. Diverticulum of Kommerell: A review of a Series and a Report of a Case with Tracheal Deviation Compromising Single Lung Ventilation. Anesth Analog. 2002:94:1462-4
6. Bent, J. Pediatric Laryngotracheal Obstruction: Current Perspectives on Stridor. Laryngoscope. 2006: 116:
7. Sisk, EA. et al. Tracheotomy in Very Low Birth Weight Neonates: Indications and Outcomes. Laryngoscope. 2006: 116: