Congenital Laryngeal Anomalies

Outline

• Laryngeal Anatomy, Embryology & Function

• Laryngomalacia

• Laryngoceles & Saccular Cyst

• Vocal Cord Paralysis

• Congenital Laryngeal Web & Atresia

• Congenital Subglottic Stenosis

• Laryngeal & laryngotracheoesophageal clefts

• Subglottic Hemangiomas

Laryngeal Anatomy

• Differences in Adults vs Infants

– 1/3 size at birth

– Narrow dimensions of subglottis and glottis

• subglottis is the narrowest (4-5mm in diameter)

– Higher in the neck

• C4 at birth vs C6-7 at 15 y/o

– Epiglottis is narrower

Laryngeal Embryology

• Laryngeal development

– 3rd week

• Respiratory primordium is derived from primitive foregut

– 4th -5th weeks

• Tracheoesophageal (TE) septum forms by fusion of (TE) folds

• Larynx develops from the 4th & 5th arches

• Primitive laryngeal aditus is T-shaped with 3 eminences

– Hyobranchial eminence becomes the epiglottis

– 2nd & 3rd eminence develops into the arytenoids

– Laryngeal lumen obliterates & then recanalize by the 10th week

Laryngeal Function

– Breathing Passage

– Airway protection

– Aid in the clearance of secretion

– Vocalization

• Symptoms of Laryngeal Anomalies

– Airway obstruction

– Feeding difficulties

– Abnormalities of Phonation

Airway Obstruction

• Symptoms

– Stridor

– Increase work of breathing with retraction, nasal flaring & tachypnea

– apnea episodes, cyanosis & sudden death

• Stridor

– Inspiratory stridor (Supraglottic & glottic)

• Collapse during negative inspiratory pressure

– Biphasic stridor (Subglottic)

– Expiratory stridor (lower tracheobronchial tree)

Airway protection

• First level- Epiglottis, aryepiglottic folds & arytenoids

• Second level- False vocal folds

• Third level- True vocal folds

• Anomalies of any of this structures lead to aspiration and swallowing dysfunction

– Symptoms- coughing, choking and gagging episodes, stasis of secretion, and recurrent pneumonia

Phonatory abnormality

• Dependent on the level of abnormality

– Muffled cry suggest supraglottic obstruction

– High pitch or absent cry is associated with glottic abnormalities

Laryngomalacia

• Most common congenital laryngeal anomaly (50-75%)

• Most frequent cause of stridor in children

• Male predominance 2:1

• Flaccidity of supraglottic laryngeal tissues

• Characterized by inward collapse of supraglottic structures during inspiration

• Anatomic Abnormalities

– Epiglottis

• Long tubular

• Displaced posteriorly on inspiration

• Inferior collapse to the vocal folds

– Short aryepiglottic folds

– Inward collapse of aryepiglottic folds (primarily cuneiform cartilages)

– Anteromedial collapse of the arytenoid cartilages

Laryngomalacia Symptoms

• Airway obstruction

– Mild to moderate obstruction

• Stridor exacerbated by exertion

– Crying, agitation, feeding or supine position

– Severe obstruction

• Substernal retraction

• Pectus excavatum with chronic severe obstruction

– Other complications

• Feeding difficulties

• GERD

• Failure to thrive

• Cyanosis, cardiac failure & death

Stridor in Laryngomalacia

• Inspiratory stridor

– Intermittent low-pitched

• Starts within first two weeks of birth

• Worsens in the first few months followed by gradual improvement

• Peak at 6 months and most are symptom free by 18 to 24 months (75%) 

Laryngomalacia Pathophysiology

• The cause of the collapse is unknown

– Theories

• Derangement of supraglottic anatomy, histology or neurologic function

• Laryngeal cartilage immaturity

– Incidence of laryngomalacia is not increased in premature infants

• Histopathology- normal microanatomy

– Subepithelial edema

• Neurologic involvement

– Associated with central apnea, hypotonia, mental retardation and early speech delay

– Abnormal Neuromuscular Control

• Muscular dilation of supraglottic structures

– Stylopharyngeus, Palatopharyngeus, Hyoglossus & Digastric

Gastroesophageal reflux

• >50% of patients with laryngomalacia

• Airway edema contributes to airway compromise

• Pathophysiology

– Increased negative intrathoracic pressure with collapsed supraglottic leads to retrograde gastric contents

• Edema and/or erythema of posterior supraglottic structures

Diagnosis of Laryngomalacia

• Awake flexible fiberoptic laryngoscopy

– Visualize supraglottic anatomy and collapse

• Fluoroscopy

• Direct laryngoscopy and bronchoscopy- evaluate for synchronous lesions (27%)

Treatment of Laryngomalacia

• Observation- most cases resolve spontaneously

• Medical management for GERD

• Surgical management- severe symptoms

– In 1922, Iglauer amputation of epiglottic redundant tissue with a wire snare

– Supraglottoplasty (CO2 laser, microlaryngeal scissors, microdebrider)

• Trim redundant tissue from:

– Lateral edges of the epiglottis

– Aryepiglottic folds

– Arytenoids

– Corniculate cartilages

– Tracheotomy

Supraglottoplasty

• Supraglottoplasty complications

– Aggressive approach

• supraglottic stenosis

• exacerbation of dysphagia with aspiration

• Rare- massive collapse of supraglottic framework needing tracheotomy placement

• Conservative excision minimizes the probability of postoperative complications

Laryngoceles & Saccular Cyst

• Anatomy

– Saccule- cecal pouch of mucous membrane in anterior roof of the laryngeal ventricle

Laryngoceles

• Dilation or herniation of the saccule

• Communicates with the lumen of the larynx

• Filled by air or mucous

• Internal-extend posterosuperior into the aryepiglottic fold

• External- protrude through the thyrohyoid membrane

• Combined- External + internal

Saccular Cyst

• Congenital cyst of the larynx or laryngeal mucocele

– No communication with the laryngeal lumen

– Filled with mucous (no air)

– Developmental- failure to maintain patency of the saccular orifice

• Two types

– Anterior saccular cyst-

• Protrudes into the ventricle

– Lateral saccular cyst

• extends into the false vocal cords and aryepiglottic folds

• Acquired Laryngoceles

– Increased pressure on the laryngeal lumen (player of wind instruments)

• Acquired saccular cyst

– Occlusion of the saccular orifice (inflammation, trauma or tumors)

• Laryngopyocele

– Infected laryngocele or saccular cyst

Symptoms

• Laryngocele

– Intermittent hoarseness and dyspnea

– Weak cry or aphonia

• Saccular cyst

– respiratory distress with inspiratory stridor

– inaudible or muffle cry

– occasionally dysphagia

• Diagnosis

– Flexible & rigid laryngoscopy

– Soft tissue neck X-ray (distended with air)

– Combined laryngocele- mass protrudes with Valsalva maneuver

• Saccular cyst- Needle aspiration confirms the diagnosis.

• Treatment

– Saccular cyst- aspiration or unroofing with cup forceps or CO2 laser (recurs)

– Endoscopic excision

• Removing remnants CO2 laser

– Open procedures for recurrence

• Lateral cervical approach incising the thyrohyoid membrane

• Protect the superior laryngeal nerve

– Intubation may be needed until edema subsides

Laser Excision of Anterior Saccular Cyst

Vocal Cord Paralysis

• Third most common congenital laryngeal anomaly producing stridor

• Unilateral & Bilateral (1:1)

• 50% are associated to other anomalies

• Acquired paralysis

– 70% association to congenital neurologic abnormalities or neurosurgical procedure to treat them

• (Meningocele, Arnold Chiari Malformation and Hydrocephalus)

– Unilateral are associated to cardiovascular anomalies (PDA) and left side is more common

• Symptoms

– Bilateral

• High-pitched inspiratory stridor

• Inspiratory cry

• Paradoxical function (pressure changes)

– close during inspiration and open during expiration

– Unilateral (less symptoms)

• weak cry and occasional breathy

• Feeding difficulties secondary to laryngeal penetration and aspiration

Vocal Cord Paralysis Diagnosis

• Awake flexible fiberoptic laryngoscopy

– record for slow motion replay

• Direct laryngoscopy

– Palpation of the glottis

– Laryngeal EMG

• Imaging of head (MRI) and chest to evaluate for associated abnormalities (Neurologic & CV)

Unilateral VC Paralysis Treatment

• Watchful waiting

– 70% of idiopathic unilateral VC paralysis resolve spontaneously

– Most within 6 month

– Feeding difficulties manage by thickening of liquids

– Speech therapy consult

– Rare surgical management

• Increased Intracranial Pressure

– early shunting or posterior fossa decompression (better outcome)

Bilateral VC Paralysis Treatment

• Tracheotomy may be necessary (50%)

• Lateralizing one or both paralyzed vocal cords

– Injurious to the developing larynx

• Excisional procedure

– Tissue removed from posterior glottis

• Endoscopic technique with laser

• More consistent results are achieved by external approach

Congenital Laryngeal Web-Atresia

• Uncommon

• Failure of laryngeal recanalization

• Most are glottic (75%)

• Symptoms

– Vocal dysfunction

• Hoarseness

• Aphonia if severe

– Airway obstruction

• Complete laryngeal atresia is incompatible with life and need emergent tracheostomy

Laryngeal Web Diagnosis

• Flexible laryngoscopy

• Direct Laryngoscopy

• Airway films if subglottic or cricoid pathology are present

Treatment

• Thin anterior glottic web

– Incision or dilation

• More significant glottic lesion

– Incision and dilation with possible revision

• >75% glottic involvement and significant subglotic extension

– Tracheotomy soon after birth

• Subglottic involvement is usually accompanied by anterior cricoid plate abnormality

– External approach with division of the web and the cricoid plate

Congenital Subglottic Stenosis

• Second most common cause of stridor

– in neonates, infants and children

• Incomplete laryngeal lumen recanalization

• Newborn larynx <4 mm (premature <3mm) • Congenital less severe than acquired • Two types – Membranous vs cartilagenous Membranous Stenosis • Circumferential & soft • Less severe than cartilagenous • Submucosal changes – Increased fibrous connective tissue layer – Mucous gland hyperplasia Cartilagenous Subglottic Stenosis • Cricoid thickening and deformation – Flattened cricoid • Smaller anteroposterior diameter – Elliptical appearance • smaller transverse diameter • Associated with laryngeal cleft Congenital Subglottic Stenosis • Symptoms – Upper airway obstruction predominate – Inspiratory stridor with progression to biphasic • Agitation worsens (increased air flow) • Mild to moderate are asymptomatic – URI lead to edema and symptoms of croup – History of recurrent or prolonged croup • Severe obstruction – Respiratory distress – Intubation may be needed Congenital Subglottic Stenosis • Diagnosis – DL & Bronch • Visualize the entire larynx • Distinction of membranous vs cartilagenous • Synchronous lesions – Measurement of the stenosis • ET tube placement at sequential size Congenital Subglottic Stenosis • Classification – Grade I < 50% obstruction – Grade II 51-70% obstruction – Grade III 71-99% obstruction – Grade IV no detectable lumen Congenital Subglottic Stenosis • Treatment of Grade I – Watchful waiting for growth • >50% obstruction may require some intervention

• Soft tissue acquired lesions

– Dilation & laser (CO2 & KTP) are sometimes effective

• Most congenital stenosis are cartilagenous

– Laser & dilation are not useful

Congenital Subglottic Stenosis

• Grade II-III treatment

– Multiple failed extubation

– Tracheostomy may be needed

• Until cricoid grows for decannulation

– Anterior cricoid split

• Successful extubation in 66-78%

• Decannulation rate 75-78%

Anterior Cricoid Split

• Horizontal skin incision over cricoid

• Vertical midline incision

– Entire cricoid

– First two tracheal rings

– Lower 1/3 of thyroid cartilage

– ET tube visualize

• Two Prolene sutures on each side of incised cricoid

• Intubated for 7-14 days (stenting)

• Grade III treatment

– Laryngotracheal decompression

• Anterior, posterior and possible lateral

– Reconstruction

• Costal cartilage

– Long term stenting 2-4 wks

• Grade IV & few grade III

– Partial cricotracheal resection

Laryngeal & Larygotracheoesophageal clefts

• rare, incidence of <0.1%

• Incomplete development of TE septum

• Communication of posterior larynx and esophagus

• Strong association with other anomalies (56%)

– TE fistula in 25%

• Laryngeal Clefting

– Interarytenoids only

– Partial or complete cricoid

• Laryngotracheoesophageal clefts

– Cervical or intrathoracic trachea

• Symptoms

– Proportional to the length

– Can be asymptomatic (minor)

– Inspiratory stridor

– Feeding problems aspiration

– Cyanotic episodes

– Recurrent pneumonia

• Diagnosis

– CXR- pneumonia

– Barium swallow- contrast spill over into the trachea

– Direct laryngoscopy best single test

• Observe and palpate the interarytenoid area

• Relationship to the vocal cords

• Treatment

– Supraglottic larynx

• Conservative management

• Swallowing therapy to prevent aspiration

• GERD evaluation and treatment

• Surgical approach

– 80% success rate with Endoscopic repair

– Extension below the vocal cords

• Surgical repair is required

• Mortality

– Laryngeal clefts, rate of 11% and 46%

• other anomalies

• Delay in diagnosis

– Intrathoracic laryngotracheoesophageal is as high as 93%

Subglottic Hemangiomas

• Benign vascular malformations

• Histological- endothelial hyperplasia

• Female predominance 2:1

• Asymptomatic at birth

– Stridor presents by 6 months (85%)

• Associated cutaneous hemangioma (50%)

• Rapid growth phase in the 1st year followed by slow resolution

• Most have complete resolution by 5 years

• 30-70% mortality rate if untreated

• Priority is to maintain the airway while minimizing potential long term sequelae

• Diagnosis

– Direct Laryngoscopy

• Compressible

• Asymmetric, usually posterolateral

• Bluish or reddish discoloration

– CT & MRI

Treatment of Subglottic hemangiomas

• Systemic steroids (principal)

– Partial regression in most patients (82-97%)

– Risk of growth retardation and increase susceptibility to infection

– Risk is reduced by alternate-day dosing regimen in the smallest doses

– Also intralesion corticosteroids has been employed with successful avoidance of tracheotomy

• Interferon alpha-2a

– 50% or greater regression of lesion in 73% of patients

– It requires prolonged therapy, blocks various steps of angiogenesis

– Side effects neuromuscular impairment, skin slough, fever and liver enzyme elevation

• Tracheotomy

– Bypass the obstructing lesion

– Waiting for the expected involution

– risks of tracheostomy as well as delay in speech and language

• Laser CO2 and KTP

– associated with a significant risk of inducing subglottic stenosis in up to 20%

• Surgical excision

– Decannulation shortly after surgery

– Avoiding tracheostomy in 85% of patients

– Laryngeal distortion or damage