vocal fold paralysis

1. VOCAL FOLD PARALYSIS
Dr. Bikram B. Karki
Resident
MCOMS

2. ANATOMY OF VAGUS NERVE
• Provides innervation to intrinsic muscles and
sensory structures
• Some fibres originate in medulla ( nucleus
ambiguus) while
others originate at higher level
• Leaves skull through jugular foramen
• Descends within carotid sheath as far as
superior border of thyroid cartilage
• Then between IJV and CCA to root of neck

3. SUPERIOR LARYNGEAL NERVE
• Arises from lower portion of inferior
ganglion
• Descend on side wall of pharynx, posterior
and
medial to ICA
• At greater cornu of hyoid bone –
• Divides into
internal laryngeal branch
external laryngeal branch

4. • Internal branch
• Descends to thyrohyoid membrane piercing
it
above superior laryngeal artery
• Inferiorly communicates with ascending
branch of RLN
• External branch
• Descend deep to superior thyroid artery
on inferior constrictor muscle
• Pierces muscle and supplies cricothyroid
muscle

5. RECURRENT LARYNGEAL NERVE
• RIGHT RLN
• Arises- right vagus nerve infront of
right subclavian artery in neck
• Winds backward around it
• Ascends obliquely behind CCA
• Into trachea - oesophageal groove
• Reaches lower pole of thyroid and intimately related to ITA

6. • LEFT RLN
• Arises- left vagus nerve in mediastinum and
loops around arch of aorta
• Passed medially and posteriorly to ligamentum
arteriosum
• Ascends in trachea - oesophageal groove
• Both right and left RLN intimately related to
medial surface of thyroid
• Passes deep to lower border of inferior
constrictor muscle
• Enter larynx behind cricothyroid joint

7. NERVE SUPPLY OF LARYNX
• motor supply:
• cricothyroid muscle: superior laryngeal nerve
• all other intrinsic muscles: recurrent laryngeal nerve
• sensory supply:
• above level of vocal cord: superior laryngeal nerve
• below level of vocal cord: recurrent laryngeal nerve

8. CLASSIFICATION
• Can be unilateral or bilateral
• On the basis of nerve involvement:
• SLN paralysis
• RLN paralysis
• Combined paralysis
( both RLN and SLN )

9. PATHOPHYSIOLOGY
• Most cases of laryngeal paralysis result – from peripheral nerve
damage
• Larynx - strong propensity for re-innervation
• However, regeneration of RLN - more problematic than most
peripheral nerve
• Re-innervation is often dysfunctional and does not yield physiologic
motion

10. SEMON’S LAW
• Motor fiber innervating abductor and adductor lay in separate bundle
• Progessive nerve injury - selectively damages abductor nerve fibre
• So in partial injury, VF lie close to midline with weak abduction
• Over times, adductor muscle weaken- VF move laterally (cadaveric
position )

11. WAGNER AND GROSSMAN THEORY
• In absence of cricoarytenoid joint fixation
• An immobile vocal fold in paramedian position - pure unilateral RLN
paralysis
• An immobile VF in lateral ( cadaveric position ) - combined paralysis
of SLN and RLN
• Widely accepted theory

12. MODERN THEORY
• Final position of paralysed VF is not static and is decided by
• Degree of paralyzed muscle atrophy and fibrosis
• Degree of re-innervation following injury
• Extent of synkinesis of all intrinsic muscle
• Crico-arytenoid joint - Fibrosis and ankylosis

13. SITE OF LESION
• Supranuclear
• Rare
• Requires B/L symmetrical lesion of cortex
• Nucelar
• Tumor of medulla
• PICA thrombosis, Bulbar palsy
• Encephalitis, Cranial polyneuritis
• MND

14. • Posterior fossa and jugular foramen
• Vernet syndrome – 9,10,11 CN
• Villaret’s syndrome- 9,10,11,12 CN and horners syndrome
• Collet- siccard syndrome- 9,10,11,12 CN
• Hughling’s jackson syndrome – 10,11,12 CN
• Schmidt’s syndrome – 10,11CN

15. Extra cranial
Cervical
region
• Penetrating injuries
• Tumors of hypopharynx,
thyroid,
upper oesophagus, PPS
• Surgery of thyroid gland
Thorax
• Aortic aneurysm
• Enlarged left atrium
• Carcinoma of bronchus
• Mediastinal tumors,
• Enlarged mediastinal glands

16. AETIOLOGY
• Congenital
• Acquired
CONGENITAL
• Idiopathic – most common
• CNS lesion
• Hydrocephalus
• Arnold- chiari malformation
• Cerebral palsy
• Mediastinal lesion
• Vascular malformation of great vessels or heart

17. ACQUIRED
• Idiopathic (13%)
• Although viral infections – influenza and infectious mononucleosis
• Inflammatory (13%)
• Pulmonary tuberculosis
• Malignant (25%)
• Lung
• Oesophagus
• Thyroid
• nasopharynx

18. • Surgical trauma (20%)
• Thyroid, oesophagus, lung ,heart, mediastinum
• Non-surgical trauma (11%)
• Aortic aneurysm
• Left atrium enlargement
• Neurological (7%)
• CVA, MS, parkinson’s disese, head injuries, diabetic neuropathy,
alcohol
• Miscellaneous (11%)
• Rheumatoid disease
• Collagen disease

19. CLINICAL FEATURES
• SLN PALSY
• Unilateral
• Voice – not severely affected
• Compensation occurs quickly
• Disability to professional voice user- significant
• Bilateral
• Voice - lower, weaker and breathy
• With good compensation - speaking voice returns but singing voice
compromised
• Cough and choking

20. RLN PARALYSIS
• Unilateral abductor paralysis
• Initial hoarsenss - disappear as normal VF compensates
• Voice tire with repeated use
• May aspirate – particularly liquid
• Bilateral abductor paralysis
• VF- paramedian position
• Voice – good but degree of stridor variable
• Stridor and dyspnoea

21. • Unilateral adductor paralysis
• Flaccid paralysed VF – Lateral position
• Voice - Weak husky, sometimes whisper only
• Aspiration
• Bilateral adductor paralysis
• Rare
• VF - lateral position
• Aphonia
• Aspiration
• Unable to cough

22. INVESTIGATION
• Assessment of vocal folds movement
• Flexible fibreoptic laryngoscopy
• Stroboscopy
• Endoscopy
• Panendoscopy – need for biopsy
• Radiology
• Chest X-ray – screen for intrathoracic region
• CT Scan from skull base to mid- thorax
• MRI – imaging skull base or CNS

23. • Modified barium swallow
• Thyroid scan
• Hematological test
• Full blood count, ESR, serology
• Laryngeal electromyography ( LEMG )
• Measures electric activity of larynx muscle via thin percutaneous
needle electrodes
• Allows better differentiation between neural lesion and other cause
• Provide evidence of re-innervation and denervation
• Localization of lesion along nerve

24. • EVALUATION OF LEMG
• Normal- joint fixation,
post scar
• Fibrillation - denervation
• Polyphasic - reinnervation
synkineses

25. MANAGEMENT FOR UNILATERAL ADDUCTOR
PARALYSIS
• Voice therapy
• Vocal fold injection
• Medialization thyroplasty
• Arytenoid adduction
• Laryngeal nerve re-innervation
• Combination of above

26. VOCAL FOLD INJECTION
• Injection of absorbable bulking material in paralysed fold to
improve glottic insufficiency
• Brunnings (1911)
• First describe injection of vocal folds
• Injected paraffin
• Arnold (1962)
• Popularized the technique
• Introduction of Teflon

27. MATERIALS USED
• Paraffin
• Teflon
• Autologous fat
• Cymetra
• Collagen
• Calcium hydroxyapatite
• Gelfoam paste
• Hyaluronic acid formulations

28. TEFLON
• Polymer of tetrafluoroethylene
• Contain 50% glycerine
• Glycerine absorbed in few weeks
• Length of effect – permanent
• Disadvantage
• Inflammatory reaction → encapsulation of remaining teflon
(granuloma )
• If placed superficially - erosion of overlying mucosa

29. AUTOLOGOUS FAT
• Insertion deep into VF ( High density )
• 30–50% - absorbed within 1st month
• Good immediate voice quality
• Length of effect - permanent
• Advantages:
• Easily harvested
• Readily available ( lower abdomen and inner thigh)
• No foreign body reaction

30. COLLAGEN
• Protein - natural constituent of lamina propria of VF
• Popularized by ford et al. for use in larynx
• Injected superficially into vocal ligament
• Length of effect - 3 – 4 months
• Advantage
• Better stability
• Reduces rate of hypersensitivity, which is < 1%

31. SILICONE
• Silicon gel
• Injected deep in body of VF – to prevent migration
• Length of effect – permanent
• Inflammatory reaction → fibrous capsule
CALCIUM HYDROXYAPATITE
• Widespread usage
• Injected deep in VF
otherwise lead to long-term hoarseness
• Length of effect - 2-5 years

32. METHODS
• Percutaneous injection
• Transoral injection
• Laryngoscopic injection

33. PERCUTANEOUS INJECTION
• May be
• Lateral approach or
• Anterior approach

34. • Lateral approach
• Through thyroid ala at level of vocal fold
• Determined by palpation of thyroid notch and
inferior border of thyroid ala anteriorly
• Vocal fold lies at midpoint

35. • Anterior approach
• Through cricothyroid membrane
• Needle is inserted - angled superiorly and
Laterally under direct visualization with
• Flexible fiberoptic nasopharyngoscope
• Transthyrohyoid approach

36. TRANSORAL INJECTION
• Apply topical lidocaine spray to
pharyngeal + laryngeal mucosa
• Patient holds tongue forward - indirect visualization
• Injection of material with curved laryngeal needle
• Direct bevel away from midline ( minimize intramucosal injection)

38. LARYNGOSCOPIC INJECTION
• Performed under general anesthesia
• Introduction of kleinsasser’s microlaryngoscope

39. • Complication
• Under injection - requires repeat procedures
• Over injection - airway compromise
• Improper placement –
subglottal extension and potential stenosis
• Granuloma formation
• Migration of materials (Teflon)

41. MEDIALIZATION THYROPLASTY
• Medialization of VF by an implant
placed
through a window in thyroid
cartilage
• Insertion of prosthesis -
lateral to inner perichondrium

42. IMPLANTS USED
• Silastic implants
(montgomery)
Carved or prefabricated
• Dense hydroxyapatite
(vocom) implants
• Gore-tex strip

43. TECHNIQUE
• Supine position
• LA - administered subcutaneously and
in four quadrants over ipsilateral lamina
• A 5-cm incision - made through platysma
• Flaps elevated Superiorly and inferiorly -
subplatysmal plane -
expose thyroid notch and inferior border (thyroid
cartilage)

44. • Strap muscles - split in midline and
• Are retracted laterally off thyroid lamina

45. • Window measures 6 mm (vertical) by 10 mm
(horizontal;
• Anterior aspect of window
• Positioned 5 to 8 mm posterior to ventral midline -
women
and 8 to 10 mm - men
• Superior aspect of window
• Placed at level of true fold
• Level of true fold
• A point half distance between
Thyroid notch and Anterior-inferior border of

46. • Outer perichondrium incised and
• Elevated from thyroid cartilage
• Cutting bur is used, followed by a diamond
bur
• To remove cartilage and to protect underlying
perichondrium

47. • Inner perichondrium is circumferentially
elevated with blunt dissector
• Template or appropriately sized
prosthesis –
placed in most effective position
• Small suction drain placed deep to strap
muscles
• Closure of skin

48. • Variations in placement of implant
• Vertical and horizontal implants relative to plane of vocal fold

49. • Advantages
• performed with local anesthesia
• potentially reversible
• better assessment of voice during procedure
• structural integrity of VF – preserved
• Disadvantages
• open procedure
• procedure is technically more difficult
• closure of posterior glottis may be limited

50. • Complications
• Incomplete glottal closure (10-15%)
• Penetration of endo laryngeal mucosa - Airway obstruction
• Chondritis
• Wound infection
• Post op hematoma, odema
• Suboptimal voice outcome – most common
• Implant migration or extrusion

51. ARYTENOID ADDUCTION
• Partial division of sternohyoid
muscle
1 cm below its insertion
• Posteriorly based flap separates
muscle away from posterior
cartilaginous border
• Paraglottic space - connected
between posterior cartilage border

52. • Posterior “cookie –bite” window -
created with kerrison rongeur
• Pyriform mucosa - dissected
posteriorly using a kitner
• Muscular process of arytenoid -
identified

53. • 4-0 prolene suture passed through
muscular process in figure of eight
fashion
• Passage of suture through ML window
• Final tying of a surgeon’s knot over
thyroid ala

54. LARYNGEAL REINNERVATION
• Horsley (1909) - reported first successful vocal fold reinnervation
( RLN )
• Two most common reinnervation techniques
• Neuromuscular pedicle (NMP)
• Ansa cervicalis to RLN (ANSA-RLN) anastomosis/transfer
• Additional techniques
• Hypoglossal nerve – RLN transfer
• Primary anastomosis of RLN
• Direct nerve implantation
• Muscle-nerve-muscle graft

55. NEUROMUSCULAR PEDICLE (NMP)
• Attempts to transfer - nerve with a portion
of its motor units intact to a denervated muscle
• Technique
• Horizontal incision - near lower border of thyroid
cartilage
• Anterior border of SCM muscle –
exposed and retracted laterally

56. • Branch of ansa cervicalis - supplies anterior belly of omohyoid
muscle
• Identified in two ways:
• First,
finding main trunk of ansa cervicalis as it crosses IJV
and tracing proximally and distally, until appropriate branch
recognized
• Second,
• By medial border of omohyoid mobilized near its attachment to hyoid
and
dissecting in medial to lateral direction along muscle

57. • NMP harvested from omohyoid muscle
• Branch of ansa cervicalis nerve to
omohyoid is removed With 2 to 3 mm
attached block of muscle

58. • NMP placed into PCA muscle ( for
lateralization )
• PCA muscle recognized by its fibers,
which pass at right angles to inferior
constrictor
• NMP placed in LCA muscle via window in
thyroid ala
• NMP - sutured in place with two or three
sutures of 5-0 nylon.

59. ANSA CERVICALIS TO RLN
• Technique
• Incision - natural creases of neck below cricoid cartilage
(thyroidectomy incison)
• Strap muscles - separated vertically in midline
• RLN - identified in tracheoesophageal groove, and
- dissected at its entrance into larynx
• Ansa cervicalis - identified along lateral border of sternothyroid
muscle
at level of omohyoid muscle or along IJV

61. • Advantage
• Procedure relatively easy
• Can be reversed ( extralaryngeal procedure )
• Subsequent use of vocal fold injection or thyroplasty is not limited
• No foreign body reaction ( No permanent implant material )
• Disadvantage
• Typically takes longer to perform
• Delay of several months - before substantial improvement in voice
occurs
• Can be difficult after thyroid surgery or after bilateral neck surgery

62. MANAGEMENT OF BILATERAL ABDUCTOR
PARALYSIS
• Good voice but lack abduction during inspiration
• Maintenance of airway is primary goal
• Airway preservation often
damages an otherwise good voice

63. • Surgical management
• Tracheostomy
• Vocal fold lateralization
• Lateralization thyroplasty
• Endoscopic cordotomy
• Endoscopic cordectomy
• Arytenoidectomy
• Laryngeal reinnervation

64. VOCAL FOLD LATERALIZATION
• EXTERNAL APPROACH
• Thyroid cartilage exposed via horizontal incision
• 16-gauge IV cannula inserted through thyroid
cartilage
• 4 mm anterior & 2 mm below mid-point of oblique
line
into laryngeal lumen, just above tip of vocal
process,
Under MLS. Guidance
• Another 16-gauge IV cannula inserted 5 mm
below
1st cannula

65. • 1-0 prolene suture threaded through inferior cannula into
laryngeal lumen
• Suture thread brought out with forceps into laryngeal lumen &
inserted into superior cannula
• External traction - on both suture ends - pull vocal cord laterally
to give 5 mm airway
• Threads tied over thyroid lamina

66. VOCAL FOLD LATERALIZATION –
ENDOSCOPIC

70. VOCAL CORDOTOMY
• Laser cordotomy - first described in 1989 by
kashima
• Only frees vocal ligament and vocal muscle
from vocal process of arytenoids
• Tissue retraction enlarges airway
• If one vocal fold seems to have - light degree of
motion,
cordotomy performed on opposite side

71. • Technique
• CO2 laser with 0.2 mm spot size used
• Performed 1-2 mm anterior to vocal
process
• Carried laterally through width of vocal
ligament
and vocalis muscle to thyroid lamina
• Opens air way posteriorly

72. • Complication
• Posterior glottic web
• Postoperative edema
• Granuloma
• Scar formation

73. POSTERIOR CORDECTOMY
• Dennis and kashima - first described
in 1989
• Technique
• CO2 laser 3.5-4 mm
• C- shaped wedge of posterior vocal
cord
excised from free border of cord,
anterior to vocal process
• Extending 4 mm laterally over
ventricular band

74. • Excision - anterior to vocal
process and
cartilage should not be exposed
• Creates 6-7 mm transverse
opening at posterior larynx

75. ARYTENOIDECTOMY
• Thornell (1948) - First endolaryngeal
arytenoidectomy
• Permanent and irreversible surgical procedure
whereby laryngeal inlet is widened
in its transverse axis
• May be
Medial arytenoidectomy
Total arytenoidectomy

76. • Medial arytenoidectomy (partial
arytenoidectomy)
• Most medial 2-3 mm of body of arytenoid
cartilage removed
• Vocal process and intra-arytenoid mucosa -
not disturbed
• Total arytenoidectomy (complete
arytenoidectomy)
• CO2 laser ablation of entire body of
arytenoid
until defect is flush with wall of cricoid ring

77. MANAGEMENT OF BILATERAL ADDUCTOR
PARALYSIS
(CHRONIC ASPIRATION)
• Non surgical management
• All oral intake is discontinued
• Alternative route of alimentation - nasogastric feeding tubes,
gastrostomy, and jejunostomy
• Appropriate antibiotics for infectious complications
• Aggressive pulmonary therapy

79. LARYNGOTRACHEAL SEPARATION (LTS)
• Division of trachea horizontally
between 2nd and 3rd tracheal rings or
at level of an existing tracheotomy
• Proximal tracheal edges closed antero-posteriorly
as blind pouch
• Distal tracheal segment - used to create
tracheostoma

80. TRACHEOESOPHAGEAL DIVERSION (TED)
• Lindeman (1975)
• Horizontal division at 4th and 5th tracheal rings
• Proximal tracheal segment –
end anastomosed to anterior esophagus
• Distal tracheal segment -
used to create a tracheostoma

81. ENDOLARYNGEAL STENT
• Solid stent
• Weisberger and huebsch
• Solid silicone laryngeal stent –
placed endoscopically
• Secured transcervically with sutures
• Tracheotomy tube necessary

82. • Vented stent
• Eliachar
• Vented silicone laryngeal stents
inserted through tracheotomy
• Secured by flexible strap of silicone that
extends
from tracheotomy tract above tracheotomy
tube
• Disadvantage
• Discomfort to patient
• Dislodgement of implant

83. VERTICAL LARYNGOPLASTY
• Incision - made along outer borders of epiglottis, aryepiglottic
folds, over arytenoids and into interarytenoid area
• Epiglottis and supraglottic larynx - closed vertically in two layers
as a tube,
with small opening left superiorly

84. EPIGLOTTIC FLAP CLOSURE
• Supraglottic larynx - approached through an infrahyoid pharyngotomy
• Supraglottic larynx - closed after edges of epiglottis, aryepiglottic
folds and arytenoids are denuded
• Tracheotomy is required

85. • Advantages
• Reversible
• True vocal cords not injured
• Deglutition and speech preservation
( if posterior laryngeal inlet left open )
• Disadvantages
• High rate of flap dehiscence and failure
• Need of transcervical approach and tracheotomy
• Supraglottic stenosis - potential complication

86. GLOTTIC CLOSURE
• Described by Montgomery
• Closed at level of true and false VF
• Technique
• Midline thyrotomy - to expose endolarynx
• True and false VF, ventricles, and posterior commissure - denuded
of mucosa
• Nonabsorbable sutures – to provide glottic closure
• Absorbable sutures - approximate margins of false vocal cords
• Tracheotomy tube necessary

88. NARROW- FIELD LARYNGECTOMY
• Before 1970, laryngectomy - considered surgical procedure of choice
• Can be performed with LA
• Preserves
1) Hyoid
2) Strap muscles
3) Hypopharyngeal mucosa as much as possible
• Closure without tension and reinforced with strap muscle
( Minimizes post-op. complications of pharyngeal stenosis and fistula)
• Tracheostomy is necessary

90. SUBPERICHONDRIAL CRICOIDECTOMY
• Technique
• Anterior aspect of cricoid cartilage exposed
• Cricoid incision
• Perichondrium of anterior cricoid cartilage-
divided vertically in midline - expose cricoid
cartilage

91. • Outer cricoid perichondrium –
elevated to posterior cricoid lamina
• Inner cricoid perichondrium –
elevated from cricoid cartilage
circumferentially
• Cricoid cartilage - removed piecemeal -
bilaterally with biting forceps
• Posterior cricoid lamina - preserved

92. • Inner perichondrium and mucosa -
divided and closed
• Both proximal and distal cut ends of
inner mucosal tube are folded in and
closed

93. • Sternohyoid muscle –
insinuated into cricoid space
• Outer perichondrium closed over
muscle
• Tracheotomy is necessary

94. • Advantage
• High success rate
• Low morbidity
• Preferable to narrow-field laryngectomy and other procedure
• Disadvantages
• Irreversible
• Need for tracheotomy
• Possibility of fistula into upper trachea

95. RECENT ADVANCES
• In recent years, botulinum toxin (botox) injection – used in laryngeal
synkinesis
• Currently being investigated include
• Gene therapy
• Stem cell therapy
• Laryngeal pacing

96. BOTULINUM TOXIN
• Neurotoxin - by clostridium botulinum
• Prevents - release of acetylcholine from axon terminals - causes
flaccid paralysis
• In case of BVFP,
• Used to block aberrant reinnervation of adductor muscles by
inspiratory motoneurons
• Thus, abductor inspiratory motoneurons would gain advantage
and become more effective in producing glottal opening
• Marie et al. - First described botox injection into bilateral adductor
muscles as a treatment for BVFP

97. GENE THERAPY
• Delivering genes by vector to injured neurons and/or denervated
muscles
• After genes are transduced into nucleus of target cells
• Produce peptides
• Promote a) RLN regeneration, synaptic formation
b) muscle growth
• Patients with BVFP caused by neurodegenerative diseases -
benefited

98. STEM CELL THERAPY
• Improve healing potential in degenerative tissue by tissue
regeneration
• Autologous stem cells - isolated from small samples of tissue from
patients –
cultured to a critical mass - re-implanted
• May promote a) regrowth of atrophic muscle mass
b) provide better platform for reinnervation
• Halum et al. (2007) - introduced use of autologous muscle-derived
stem cell for treatment of VFP

99. LARYNGEAL PACING
• Application of functional electrical stimulation (FES) of the PCA
muscle
• Mueller and his associates - recently conducted a clinical trial of
unilateral pacing in 9 patients with BVFP
• Used minimally invasive electrodes activated by
an external pacemaker affixed to the chest wall
• Significant improvement in ventilation
( no negative effect on voice quality)