Presentation on theme: "Unilateral Vocal Cord Paralysis"— Presentation transcript:
1Unilateral Vocal Cord Paralysis Nora Malaisrie, M.D.Faculty Discussant: Natasha Mirza, M.D.Thursday, July 24, 2008Good morning and thank you for coming. Today I will be talking about unilateral vocal cord paralysis. My faculty discussant is Dr. Mirza.Otorhinolaryngology: Head and Neck Surgery at PENNExcellence in Patient Care, Education and Research since 1870
2Introduction Affects quality of life Potential morbidity and mortality A sign of a disease process with multiple etiologies, necessitating thorough evaluationMultiple therapeutic options that must be tailored to the patientUnilateral vocal cord paralysis has a major effect on quality of life with the potential for signficant morbidity and mortality.Unilateral VCP is a sign of disease process and not a diagnosis. Multiple etiologies exist that may account for its presentation, thus necessitating a thorough evaluation.Multiple therapeutic options exist which may be combined and tailored to suit the patient.
3AnatomyUpper motor neurons from cerebral cortex to nucleus ambiguus in the medullaLower motor neurons from nucleus ambiguus exit the medulla as the vagus nerveVagus nerve exits the skull base via the jugular foramenBranchesPharyngeal branchSuperior laryngeal nerveRecurrent laryngeal nerveCorticobulbar fibers from cerebral cortex travel through the internal capsule to synapse on motor neurons in the nucleus ambiguus in the medullaLower motor neurons leave the nucleus ambiguus and exit the medulla between the olive and pyramid as a series of 8-10 rootlets which coalesce into a single nerve root, the vagus nerve.The vagus nerve exits the skull base via the jugular foramenThe vagus nerve descends in the carotid sheath giving off 3 major branches: pharyngeal branch, superior laryngeal nerve and the recurrent laryngeal nerve
4Anatomy Recurrent laryngeal nerve Muscles 0.5% right non-recurrent laryngeal nerveMusclesLateral cricoarytenoidPosterior cricoarytenoidThyroarytenoidInterarytenoidThe superior laryngeal nerve provides sensation to the glottis and supraglottis as well as motor input to the cricothyroid muscle, which controls vocal fold lengthening and pitch.The RLN axons travel with the vagus nerve and branch off at the level of the aortic arch on the left and the subclavian artery on the right. On the left, the RLN travels in or lateral to the tracheoesophageal groove to enter the larynx posteriorly, adjacent to the cricothyroid joint. On the right, the RLN takes a more oblique and lateral course to enter the larynx.The RLN supplies sensation below the glottis and innervates all intrinsic muscles of the larynx excluding the cricothyroid muscle. These include the posterior cricoarytenoid, lateral cricoarytenoid, thyroarytenoid and interarytenoid muscles.A nonrecurrent LN, which branches at the level of the cricoid cartilage, almost always occurs in the right neck in conjunction with a retroesophageal right subclavian artery. It will occur in the left neck in the case of situs inversus.
5Etiology Dysfunction at Brain and brainstem nuclei Vagus nerve Recurrent laryngeal nerve* Etiology of unilateral VCP can occur because of dysfunction at the brain and brainstem nuclei, at the vagus nerve and at the RLN.
7Etiology: Tumor infiltration or mass compression Skull baseThyroidEsophagusLungSkull base, such as paragangliomaThyroid: Thyroid malignancy, benign lesion, goiterEsophageal or lung, such as a malignancy
8Etiology: Systemic disease Systemic lupus erythematosusSarcoidosisAmyloidosisTuberculosisCharcot-Marie-ToothMitochondrial disordersPorphyriaPolyarteritis nodosaSilicosisPoor fear ee ah
9Etiology: Medications Vinca alkaloidsVincristine and vinblastineUnilateral or bilateralDose relatedResolves with dose adjustment or cessationVinca alkaloids: Used in hematologic malignancies and head and neck sarcoma. It has a known neurotoxicity effect that may result in unilateral or bilateral vocal cord paralysis. This is a dose related effect that resolves with dose adjustment or cessation.
10Etiology: Traumatic Iatrogenic: Surgical Iatrogenic: Non-surgical ThyroidectomyAnterior cervical spine proceduresEsophagectomyThymectomyCarotid endarterectomyCardiothoracic surgeryAortic surgeryCoronary artery bypass graftingPulmonary lobar resectionMediastinoscopyIatrogenic: Non-surgicalEndotracheal intubationArytenoid dislocation, subluxationTapia’s syndromeNasogastric tube placement1Non-iatrogenicBlunt or penetrating trauma to the neckTraumatic injury is the most common cause of unilateral VCP. Traumatic causes are iatrogenic and non iatrogenic.Surgical causes are the most common in this category, and this includes thyroidectomy, anterior cervical spine procedures, esophagectomy, thymectomy, CEA, and CT surgeries.Non surgical causes include-Tapia syndrome: This is a recurrent laryngeal and hypoglossal nerve paralysis caused by cuff of the endotracheal tube on the thyroid cartilage.-NGT syndrome: Triad of NGT placement, throat pain and vocal cord paralysis. A rare syndrome that is usually associated with bilateral VCP. Pressure phenomenon causes local irritation, edema and ulceration of laryngeal tissues causing vocal cord injury. Caused by rubbing of laryngeal structures against a fixed NGT, cricoid compression against the spine while in the supine position and tonic contraction of the CP muscle against a fixed NGT injuring the posterior cricoid mucosa.Finally, non iatrogenic traumatic causes include blunt or penetrating trauma to the neck.Brousseau et al. A rare but serious entity: nasogastric tube syndrome. Otolaryngol Head Neck Surg Nov;135(5):
11Etiology: Idiopathic Not well understood Possible infectious cause Lyme diseaseTertiary syphilisEpstein-Barr virusHerpes simplex virus Type IDiagnosis of exclusionUrquhart et al. showed that 26% of patients with a diagnosis of idiopathic VCP had a preexisting neurologic condition and 20% developed a subsequent CNS condition.1Idiopathic unilateral VCP is not well understand.A possible infectious cause has been proposed because many patients report an antecedent URI before the onset of vocal symptoms. However, there is no data to suggest that steroids or antivirals affect the course of the disease.In a retrospective analysis, Urquhart et al. showed that of 193 patients diagnosed with VCP, 18% (35) were idiopathic. Of these 35 patients, 26% (9) had a preexisting neurologic condition and 20% (7) developed a subsequent CNS condition (CVA, post polio syndome, polyneuorpathy associated with a paraneoplastic syndrome). 23% (8) resolved within 5 months.Thus careful neurological evaluation of patients with a diagnosis of idiopathic VCP is recommended.Urquhart et al. Idiopathic vocal cord palsies and associated neurological conditions. Arch Otolaryngol Head Neck Surg Dec;131(12):
12EtiologyIn a retrospective analysis of 363 patients, Rosenthal et al. showed that unilateral VCP was caused bySurgery (46%)Idiopathic (18%)Malignancy (13%)Lung was most commonRosenthal et al. did a retrospective review of all patients within a tertiary center between with vocal fold immobility. These results were combined with the results from a previous study fromFrom , surgery was most common cause at 47%, followed by idiopathic and malignancy, in which lung was most common.Rosenthal et al. Vocal Fold Immobility: A Longitudinal analysis of Etiology Over 20 Years. Laryngoscope Oct;117(10):
13EtiologyRosenthal et al. showed that surgical causes of unilateral vocal cord immobility were the result ofNon-thyroid surgeries (67%)Anterior cervical spine (15%)Carotid endarterectomy (11%)Cardiac (9%)Thyroid surgeries (33%)Thyroid (26%)Parathyroid (6%)Thyroid and parathyroid (1%)In the same study, Rosenthal et al. analyzed all surgical causes of unilateral vocal cord paralysis and showed that the most common cause were non-thyroid surgeries at 67%. These included cervical spine procedures, CEA and cardiac procedures.Thyroid and parathyroid surgeries comprised the remaining 33%.Rosenthal et al. Vocal Fold Immobility: A Longitudinal analysis of Etiology Over 20 Years. Laryngoscope Oct;117(10):
14EtiologyRosenthal et al. compared unilateral VCP from toSurgical causes doubledMalignant causes decreasedFurther, Rosenthal et al. compared causes of unilateral VCP from to and found thatSurgical causes doubled (CLICK) whileMalignant causes decreased (CLICK)Rosenthal et al. Vocal Fold Immobility: A Longitudinal analysis of Etiology Over 20 Years. Laryngoscope Oct;117(10):
15EtiologyRosenthal et al. compared their study to previous studies to evaluate the changing etiology of unilateral VCP.Increase in surgical causes, with a greater proportion attributable to non-thyroid surgeriesDecrease in malignant causesRosenthal et al also made a comparison of their series of unilateral VCP to previous series earlier in the century in order to analyze changing etiology.There was a statistically significant increase in surgically related causes, with a greater proportion of non-thyroid surgeries. This may be due to the increase in the number of surgeries performed, including thyroidectomy, anterior cervical approach to the spine, and CEA. (CLICK)There was a statistically significant decrease in malignant causes. This may be due to earlier detection and treatment of lung cancer. (CLICK)Finally there was a statistically significant decrease in CNS, aortic/cardiac and traumatic causes. (CLICK)Rosenthal et al. Vocal Fold Immobility: A Longitudinal analysis of Etiology Over 20 Years. Laryngoscope Oct;117(10):
16Evaluation – History Symptoms Past medical and surgical history Voice changesHoarseness to aphoniaCompensatory voice changesVocal fatigue, neck painAspirationWeak, ineffective coughPast medical and surgical historySocial historyEvaluation of unilateral VCP includes a thorough history and physical exam.SymptomsVoice change: Patients may report symptoms ranging from hoarseness to complete aphonia. A breathy, weak voice is due to incomplete glottic closure and subsequent “air wasting” during speech, which may give the patient a sensation of “shortness of breath”. A “watery” or “gurgly” quality to the voice is due to pooled secretions in the pyriform sinus.Patients may compensate with increased respiratory effort and a hyperfunctional supraglottic voice, contracting the supraglottis laterally to appose the false cords or in the anterior-posterior dimension to appose the epiglottis to the arytenoids or the arytenoids to the contralateral false folds. This will produce a voice not dissimilar to muscle tension dysphonia, causing a rough, pitch-locked low frequency voice.Other patients may compensate with a high pitched voice, referred to as a “paralytic falsetto”. This is an 85 Hz increase in fundamental frequency caused by compensatory contraction of the ipsilateral cricothyroid muscle, which remains innervated.These compensatory changes causes an increase in paralaryngeal contractions and subsequently will result in vocal fatigue and neck pain.Incomplete glottic closure may also result in aspiration of liquids. High vagal injuries can cause dysphagia to solids due to denervation of the pharyngeal constrictors. High vagal injuries can also exacerbate aspiration due to SLN involvement and loss of sensation.Incomplete glottic closure also results in a weak and ineffective cough due to the inability to create positive end expiratory pressure (PEEP). This loss of auto-PEEP may even affect pulmonary function as well as maneuvers that require a strong Valsava.PMH: One must assess any history of neurologic or rheumatologic disease to explain an idiopathic unilateral VCP, previous surgeries, prolonged intubations, or trauma. In addition, significant cardiopulmonary cormorbidites may affect the patient’s surgical options.Social history: One must also assess risk factors for malignancy as well as a good voice history, specifically the patient’s vocal habits and needs.
17Evaluation – Physical Exam Cranial nerve examNasopharyngolaryngoscopyVocal cord asymmetryHorizontal and vertical positionGlottic gapPoooled secretionsAspirationMaximal phonation time (MPT)Supraglottic hyperfunctionThe physical exam includes a full head and neck exam with particular attention to the cranial nerves. Evaluate the gag reflex and palatal elevation, as a high vagal injury will cause palatal deviation to the intact side.NPL is performed with an evaluation of voice during various phonatory tasks and at several frequencies. (CLICK)Attention to asymmetry, vocal fold bowing and lesions.Horizontal position: Cadaveric (lateral), paramedian, median. Vertical positionMaximal abduction and adduction may be achieved with the “ee-sniff” maneuver. It is important to note that any ad-duction of the affected cord does not represent partial innervation as the interarytenoid muscle has bilateral innervation.Glottic gap on phonation.Pooling of secretions in the pyriform sinus on the affected side, aspiration of secretionsMaximal phonation time (MPT) is measured by having the patient take a deep breath and phonate /i/ for as long as possible. A normal MPT is 25 sec. Patients with VCP are usually less than 10 sec. Shorter times indicate severe glottic incompetence, worse voice and increased vocal fatigue. However, it is important to note that MPT is affected by pulmonary disease.In long standing unilateral VCP, supraglottic hyperfunction (CLICK) may obscure visualization of the vocal folds. Asking the patient to “sigh” or “hum through the nose” may remove this compensatory muscle contractions.
18Evaluation – Physical Exam VideostroboscopyIncreased amplitude of vibrationVocal fold height differenceVocal process contactVideo stroboscopy is performed to examine glottic gap and mucosal wave (CLICK)One may note an increased amplitude of vibration of the paralyzed cord because of the atrophic nature of the denervated vocalis muscle.One may also note vocal fold height differencesAnd the status of vocal process contact during phonation, which will affect the surgical procedures undertaken
19Evidence Based Medicine Levels and Grades * Now I will discuss the evaluation of the diagnosis of unilateral VCP. Here is a table of evidence based medicine levels as they will apply to the next few slides. Please note that Level I evidence is the highest, characterizing a randomized controlled trial or systemic review of randomized controlled trials.
20Evaluation – LabsIn a survey of 84 otolaryngologists, Merati et al. found that20% found that serum testing was necessaryThe most commonly ordered labs were RF, Lyme titer, ESR, ANA1Routine labs not supported by the literature if cause unknown.2,3Merati et al. performed a survey of 84 members of the American Broncho-Esophagological Association regarding the evaluation of unilateral VCP with no known precipitating cause and showed that20% found the ordering of serum testing “often or always necessary”.The most commonly ordered labs were RF, Lyme titer, ESR and ANAHowever, there is no level I or II evidence to support this but only anecdotal or case series information to support these tests.1. Merati et al. Diagnostic testing for Vocal Fold Paralysis: Survey of Practice and Evidence-Based Medicine Review. Laryngoscope Sept; 116:2. Terris et al. Contemporary evaluation of unilatereal vocal cord paralysis. Otolaryngol Head Neck Surg Jul;107(1):84-90.3. MacGregor et al. Vocal Fold palsy: a re-evaluation of investigations. J Laryngol Otol. 1994;108:
21Evaluation Assess swallow function and aspiration Modified barium swallowFunctional endoscopic evaluation of swallowing (FEES)No additional work up required if clear cut etiologyAspiration is assessed with a MBS or FEES (CLICK)If there is a clear cut temporal relation between surgical or iatrogenic trauma and VCP, no additional workup is necessary. However, if the etiology is unclear, imaging studies are required.
22Evaluation – Imaging Modalities CXR: May be most useful and cost-effective.CT with contrast: May evaluate the entire course of the RLN.MRI: May be useful in patients with polyneuropathyLiterature does not demonstrate superiority of any single modalityIn the same study by Merati et al of otolaryngologists in the ABEA, the majority believed that CXR or CT were “always or often necessary” in the evaluation of idiopathic unilateral VCP.Imaging modalities include CXR, CT and MRI. However, no studies compare any two modalities in a prospective manner.CXR: Historically, CXR has been the principal diagnostic radiograph ordered for idiopathic unilateral VCP. Terris et al found CXR to be the most useful test, securing a diagnosis in 48% of those in which the cause was not apparent, and thus was also the most cost-effective. In addition, they found that no patients developed a malignant pathology following the initial examination. Interestingly, those physicians who had finished their training within the last 5 years of the study were more likely to obtain advanced imaging than those with more than 25 years experience. This resulted in a mean difference in cost of evaluation of $2300 versus $306.CT skull base to chest: With the advent of CT scanning, CT may be superior to CXR in evaluating the course of the RLN from the skull base to the chest. In a retrospective study of patients with extralaryngeal causes of VCP, Glazer et al. found that 82% had a neoplasm along the course of the RLN. Interestingly, 72% of those with a left RLN paralysis and an aortopulmonary mass had a normal CXR.In a recent prospective study by El Badawey et al. of 86 patients with unexplained VCP, 36% had positive findings on CT. 88% of those with positive CT findings had mediastinal adenopathy with or without a pulmonary mass. Patients with negative CT findings were followed for 6-18 months with no positive findings to explain the VCP.MRI brain: Useful in patients with associated cranial polyneuropathies in order to identify intracranial/proximal extraaxial mass lesions as well as RLN invasion in thyroid cancer. However, its use has not been clearly identified in the literature in the evaluation of vocal cord paralysis.Only level IV evidence to support the role of imaging in the evaluation of vocal cord paralysis with no known cause. It may be argued that CXR serve as a screening tool given its low cost and high yield. However, if a positive CXR is to be followed by a CT to further delineate a lesion and a negative CXR is to be followed by a CT, then one may consider pursuing a CT neck and chest as the initial imaging modality.1. Merati et al. Diagnostic testing for Vocal Fold Paralysis: Survey of Practice and Evidence-Based Medicine Review. Laryngoscope Sept; 116:2. Terris et al. Contemporary evaluation of unilatereal vocal cord paralysis. Otolaryngol Head Neck Surg Jul;107(1):84-90.3. Glazer et al. Extralaryngeal causes of vocal cord paralysis: CT evaluation. AJR am J Roentgenol 1983;141:4. ElBadawey et al. Prospective study to assess vocal cord palsy investigations. Otolaryng Head Neck Surg 2008; 138:
23Evaluation – Laryngeal electromyography (LEMG) Needle electrode placement into thyroarytenoid and cricothyoid muscleAssessMuscle at restVoluntary motor unit recruitmentMay not be useful in diagnosisLaryngeal EMG is currently used in the diagnosis, prognosis and treatment of many disorders, including dystonias, vocal cord paralysis and neurolaryngological disorders as well as for placement of botulinum toxin injections. It is usually performed by a neurologist or laryngologist by placing needle electrodes into the musculature.Electrodes are placed into the TA and CT muscle.Placement into TA is performed via the cricothyroid membrane, directing the needle superiorly into the left or right TVC.Placement into the CT muscle is more difficult because of the proximity of the strap muscles. The needle may be placed midline and walked superiorly and laterally over the cartilage with placement into the CT confirmed with a characteristic “pop” sound on EMG and activation with high pitch.Placement into the PCA has been advocated by some but is technically more difficult and uncomfortable for the patient in the office setting. However, testing of the PCA may be used to confirm RLN injury.EMG specifically assess theMuscle at rest andVoluntary motor-unit recruitment: During vocalization or valsava, there should be a concomitant increase in the number and rate of observed motor units as the force of contraction increases. EMG should show a plethora of motor unit potentials. (CLICK)Normal motor unit potential should be triphasic and relatively narrow, approximately 4 msec in duration. (CLICK)EMG may not be useful in diagnosing VCP because of sampling error. When motor unit activity is abnormal, it may be difficult to know that the electrode is in the right location. In addition, test retest reproducibility is difficult because one cannot know the electrode was placed in the exact same place. Sataloff et al performed an evidence based review on 11 studies in the diagnosis of vocal fold paresis versus mechanical fixation of the cricoarytenoid joint and found only level IV evidence to support the use of EMG.Munin et al. Laryngeal electromyography: diagnostic and prognostic applications. Otolaryngol Clin North Am Aug;33(4):Sataloff et al. Practice parameter: laryngeal electromyography (an evidence-based review). Otolaryngol Head Neck Surg 2004; 130:
24Evaluation – LEMGMunin et al. reported that LEMG obtained 1-6 mo from onset may be helpful in determining prognosis.1Prognosis good if there is absent spontaneous activity and normal recruitment with normal motor unit morphologyPrognosis poor if there is spontaneous activity with absent recruitment and presence of fibrillations2Wang et al. reported that LEMG obtained 2-6 mo from onset have a sensitivity and PPV of 93% and accuracy of 87%.2Munin et al. reported that LEMG obtained 1-6 mo from the onset of VCP may be helpful in determining prognosis.1(CLICK) Absent spontaneous activity, normal recruitment, and normal motor unit potentials signify a good prognosis.(CLICK) Spontaneous discharges during rest, absent recruitment, and presence of fibrillations or denervation nerve potentials signify a poor prognosis.Conditions associated with good prognosis: Association with intubation, blunt trauma or idiopathic etiology.Conditions associated with poor prognosis: Nerve transection, nerve invasion by tumor, association with thoracic aneurysm, progressive neurologic disorders.When Wang et al looked at LEMG from 2-6 months from onset compared to 1-6 months, they increased their PPV (TP/TP+FP) to 93% and accuracy (TP+TN/all) to 87%. Thus EMG may be able to identify those patients with a positive EMG and persistent unilateral VCP as having a poor prognosis and thus requiring more definite surgical management.Munin et al. Laryngeal electromyography: diagnostic and prognostic applications. Otolaryngol Clin North Am Aug;33(4):Koufman et al. Diagnostic laryngeal electromyography: The Wake Forest experience Otolaryngol Head Neck Surg Jun;124(6):603-6.Wang et al. Prognostic indicators of unilateral vocal fold paralysis. Arch Otolaryngol Head Neck Surg Apr;134(4):380-8.
25Differential Diagnosis Cricoarytenoid fixationCaused byJoint subluxation/dislocation with ankylosisJoint fixation by rheumatoid arthritis or goutNormal EMGDirect laryngoscopyLaryngeal malignancyThe differential of unilateral VC immobility includesCA joint dislocation/subluxation caused by intubation trauma or blunt trauma to the neck leading to joint ankylosis or by joint fixation by rheumatoid arthritis or goutEMG is normal and direct laryngoscopy with palpation of the CA joint shows no passive mobility.Laryngeal malignancy with involvement of the joint or the thyroartyenoid muscle is also included in the differential.EMG may show decreased amplitude and recruitment of the TA muscle. However, EMG findings of other muscles were normal. NPL will also show a laryngeal lesion.
26TreatmentGoal: Improve voice and prevent aspiration. Patient factors affect treatment strategies.Presence of aspirationNature of nerve injuryVocal demandsMedical comorbiditiesLEMG findingsStrategies:Observation for 6-12 monthsSpeech and swallow therapySurgical interventionTemporary: Vocal fold injectionPermanent: Vocal fold injection with durable material, medialization thyroplasty +/- arytenoid adduction or laryngeal reinnervationThe goal of treatment is to improve the voice and prevent aspiration. However, patient factors affect treatment strategies.The presence of aspiration favors early treatmentNerve transection and thus poor prognosis for spontaneous recovery favors early treatmentVocal professionals, such as salespeople, teachers or attorneys, favor early treatment, nonvocal professionals and those with limited voice use favors observationSignificant medical comorbidities, such as cardiopulmonary disease, may make general anesthesia unsuitable and thus favor in-office treatmentGood prognosis according to LEMG findings favors observation or temporary vocal fold injectionStategies includeObservation for 6-12 months if there is good prognosis for spontaneous recovery and no sign of aspirationSpeech and swallow therapySurgical intervention. Temporary surgical intervention includes vocal cord injection with shorter duration material. Permanent surgical intervention includes vocal cord injection with durable material, medialization thyroplasty, arytenoid adduction, and laryngeal reinnervation.
27Treatment – Speech and swallow Provides voice therapyTeaches vocal hygiene and compensatory strategiesIdentifies and eliminates counterproductive compensatory strategiesPre-operative and post-operative assessmentSpeech therapy provides several important functions.Provides voice therapy with attention to vocal exercises, head and neck muscle relaxation, intrinsic laryngeal muscle strength and agility and abdominal and thoracic muscle strength for optimal breathing.Teaches vocal hygiene (smoking cessation, hydration) and compensatory strategies, such as pitch modificationIdentifies counterproductive compensatory strategies which produce voice strain, voice fatigue and neck discomfortPre-operative assessment to document and quantitate vocal fold dysfunction, to determine the appropriate treatment modality, to prepare the patient psychologically for surgery, and to provide training for optimal post operative phonation.Post-operative assessment to determine efficacy of treatment and to provide post operative training for optimal phonation.With excellent speech therapy, some patients, especially those with VC in the median position with equal tonicity, may compensate well and avoid surgery altogether.
28Treatment – Injection laryngoplasty Injection with temporary materials temporizes the voice until return of functionMany materials available for augmentationInjection laryngoplasty is the first surgical option and ranges from short to long term injection materials. Injection with temporary materials temporizes the voice if return of function is expected, if there is favorable prognosis on LEMG, or until more definitive surgical procedure is performed.There are several materials availableTeflon (CLICK): Introduced in the 1960’s, teflon was used for permanent medialization. However, the nonviscous substance requires a large bore needle, making it difficult to place in the vocal fold. Disadvantages include the development of granulomas as well as migration of Teflon into tissues. Teflon granulomas are difficult to remove and produce poor vocal outcomes. (CLICK)Bovine collagen: Requires allergy testing 6 weeks before injection due to a 3% rate of hypersensitivity reaction. Cross linked bovine collagen (Zyplast) is associated with a lower rate of hypersensitivity. It provides a 6 month of duration and thus is beneficial for the patient who is expected to recover. Overinjection by 20-30% is necessary because of expected resorption.Human collagen is harvested from the skin of the patient and processed to obtain collagen, thus eliminating hypersensitivity reaction. However preparation is expensive and may take several weeks. (CLICK)Micronized Alloderm (Cymetra) is made from acellular dermis from cadaveric tissue. There is no need for allergy testing due to low immunogenicity. In addiiton, the matrix of dermal components facilitates fibrous ingrowth and angiogenesis after injection. However length of effect is variable and unpredictable. (CLICK)Fat: Viscoelastic properties of fat are similar to those of vocal cord lamina propria and injection is “forgiving” in that a less than perfect injection placement can still produce good voice result. However, the length of effect is also variable and unpredictable and there is donor site morbidity. In addition, overinjection of 30-50% is required for the expected resorption of fat in first 4-6 weeks. (CLICK)Calcium hydroxylapatite (Radiesse): The mineral component of bone, Radiesse shows stability over 2 years with a minimal inflammatory response. The carrier gel is water based requiring a small amount of overinjection. (CLICK)Hyaluronic acid: A component of ECM and thus nonimmunogenic, HA promotes recruitment of fibroblasts and ingrowth of new connective tissue. It is the closest match in viscoelastic properties to the vocal cord of any injectable.O’Leary et al. Injection Laryngoplasty. Otolaryngol Clin N Am 2006;39:43-54.
29Treatment – Injection laryngoplasty Method: Under local anesthesia via transcutaneous or oral approach with NPLAdv: Useful for poor surgical candidates, voice feedbackDisadv: Pt discomfortThe injection is placed into the paraglottic space bounded medially by the conus elasticus and vocal ligament and laterally by the thyroid cartilage perichondrium. This area accommodates a volume of approximately 0.76ml. Injection is placed in the deep portion of the vocal fold in order to avoid disruption of the superficial layer of the lamina propria.This procedure may be performed in the office under local anesthesia with direct visualization by NPL. This may be performed transcutaneously or orally.Transcutaneous: The needle is placed just inferior to the halfway point between the superior notch and inferior border of the thyroid cartilage (CLICK). In older patients in whom the thyroid cartilage is calcified, the needle is placed through the cricothyroid membrane and aimed superiorly (CLICK).Transoral: Topical anesthetic such as benzocaine is applied to the oropharynx and 4% lidocaine is applied to the larynx.There are many advantages to office injection laryngoplasty. It is useful for patients with significant comorbidities who are not surgical candidates and allows for immediate voice feedback to determine the adequacy of injection.The obvious disadvantage is patient discomfort.
30Treatment – Injection laryngoplasty * Office injection of the L TVC with RadiessePre-injectionPost-injection
31Treatment – Injection laryngoplasty Method: Under general anesthesia via direct laryngoscopyAdv: Patient comfort, improved precisionDisadv: No voice feedbackComplications: Under-injection, over-injection, improper placement, foreign body reactionInjection laryngoplasty may also be performed under general anesthesia via direct laryngoscopy with a small ETT or jet ventilation (CLICK)Advantages of this technique include patient comfort and improved precision - especially for those materials that must be overinjected, such as collagen, fat and CymetraDisadvantages include the lack of voice feedback to guide injection. This is an issue for materials that do not resorb and must be injected in a precise amount, such as Teflon or Radiesse.Complications of injection laryngoscopy include underinjection requiring repeat procedures, overinjection causing airway obstruction, improper placement causing subglottic extension, and foreign body reaction such as Teflon granuloma.
32Treatment – Medialization thyroplasty Direct medialization of the vocal cordPerformed alone or with arytenoid adduction or reinnervation procedureImplant materialCarved or prefabricated Silastic implantHydroxyapatite implantGore-Tex stripsLaryngeal framework surgery is a long term solution to unilateral VCP which may be performed after the acute phase of paralysis when there is a poor chance of spontaneous recovery. The first is medialization thyroplasty, which is the medialization of vocal fold via direct external displacement using an implant which addresses the 3-D nature of the patient’s paralysis.This is performed alone or with arytenoid adduction or reinnervation procedure under local anesthesia with IV sedation and under direct visualization via NPL.There are options for the type of implant materialCarved Silastic implants, prefabricated Silastic implants (Montgomery) and dense hydroxyapatite (VoCoM) implants are routinely used. Prefabricated implants with matched-sizing templates allow for a more rapid determination of the correct implant position and size.Gore-Tex strips have also been used with success, and in some situations may provide greater adaptability than prefabricated systems.Procedure:Thyroid cartilage exposedThe superior aspect of the window is at the vocal fold level. A point half the distance between the anterior-inferior border of the thyroid cartilage and the thyroid notch defines the level of the true fold. From this point, a line drawn posterior and parallel to the inferior border of the thyroid cartilage will approximate the level of the true fold.The outer perichondrium is incised and removed.A cutting burr, followed by a diamond burr, is used to remove cartilage and protect the underlying periochondrium.The inner perichondrium is circumferentially elevated with a blunt dissector.A template or appropriately sized prosthesis is placed in the most effective positionThere are variations in placement of the implant. This diagram shows vertical and horizontal implants relative to the plane of the true vocal fold.The implant is manipulated while asking the patient to phonate under direct visualization with NPL in order to obtain the best voice outcome. The implant is then secured.
33Treatment – Medialization thyroplasty Adv: Local anesthesia, voice feedback, reversible, vocal fold integrity preservedDisadv: Open procedure, technically difficult, closure of posterior gap limitedComplications: Penetration of laryngeal mucosa, infection, chondritis, implant migration, airway obstruction, undercorrectionHere are video clips of medialization thyroplasty using Gortex. (CLICK) (CLICK)Advantages include the use of local anesthesia, immediate voice feedback, reversability, and preservation of vocal cord integrity.Disadvantages are that this is an open procedure that is technically difficult. In addition, closure of a posterior glottic gap is limited.ComplicationsPenetration of laryngeal mucosa, infection, chondritis, implant migration, and airway obstructionUndercorrection or incorrect placement with incomplete glottic closure occurs in 10-15%, usually in those injured acutely with progressive atrophy after denervation or in the setting of vocal edema caused by surgical manipulation.
34Treatment – Arytenoid adduction Adjunct to medialization thyroplasty if large posterior glottic gap or vocal folds at different levelsKraus et al. showed that when combined with a medialization thyroplasty, there was improvement in symptoms as well as voice parameters.1Mucullough et al. showed that when combined with medialization thyroplasty, functional results exceeded the improvement attained with medialization alone.2Another form of laryngeal framework surgery is artyenoid adduction, which produces medialization of the vocal cord by mimicking the action of the lateral cricoarytenoid muscle and rotating the arytenoid cartilage by placing a suture from the muscular process of the arytenoid and attaching it to the inferior cornu of the thyroid cartilage.This is useful as an adjunct to medialization thyroplasty if there is a large posterior glottic gap or if the vocal cords are at different vertical levels since medialization thyroplasty may not correct a large gap and does not address differences in vocal fold height.Kraus et al. combined AA with Silastic implant medialization thyroplasty and showed symptom improvement, specifically hoarseness, aspiration, dyspnea, pneumonia and dysphagia. Objective vocal parameters, such jitter (cycle to cycle change in frequency), shimmer (cycle to cycle change in intensity), and mean phonation time, were also improved.McCullough et al. combined AA with Goretex implant medialization thyroplasty and showed improvement in subjective voice assessment as well as MPT greater than in thyroplasty alone.Kraus et al. Arytenoid adduction as an adjunct to type I thyroplasty for unilateral vocal cord paralysis. Head Neck Jan;21(1):52-9.Mucullouch et al. Arytenoid adduction combined with Gore-Tex medialization thyroplasty. Laryngoscope Aug;110(8):
35Treatment – MT + AAComplications of medialization thyroplasty with arytenoid adductionAbraham et al. compared ML + AA patients to ML alone and found no statistical difference.AA requires more extensive tissue dissection in order to expose the arytenoid cartilage compared to medialization thyroplasty alone. This includes retraction of the larynx away from the field and careful dissection of the pyriform sinus mucosa in order to expose the muscular process of the arytenoid cartilage.In a retrospective study, Abraham et al reported no statistical difference in overall complications between patients undergoing MT + AA compared to MT alone. However there is an increased risk of temporary vocal cord edema and local wound complications because of the more extensive tissue dissection required. Two patients did require emergent tracheostomy but were later decannulated. They concluded that the ability to close a large posterior gap is justified by a similar complication rate.Abraham et al. Complications of type I thyroplasty and arytenoid adduction. Laryngoscope Aug;111(8):
36Treatment – Laryngeal reinnervation Goal: Increase bulk and toneIndications: Poor chance of spontaneous recoveryNerve characteristicsRLNAnsa cervicalisTypesNeuromuscular pedicleNerve-nerve anastamosisMay be combined with temporary injection laryngoplasty until reinnervationThe goal of laryngeal reinnervation procedures is to prevent denervation atrophy of the vocal fold and to provide bulk and tone to the denervated muscles, resulting in less asymmetry between the normal and reinnervated vocal fold.It is indicated in unilateral VCP where these is a poor chance of spontaneous recovery. The recommended waiting time is at least 12 months. In the case of ansa to RLN anastamosis, this may be done sooner in the setting of a known transected nerve.Nerve characteristicsThe RLN has motor fibers which are intermixed before branching within the larynx. Thus selective reinnervation of the RLN is impractical. Reinnervation instead produces laryngeal synkinesis, with adductor and abductor nerve fibers nonselectively innervating the laryngeal muscles. Thus all muscles innervated by the RLN are stimulated with no resulting functional movement of the vocal fold.The ansa cervicalis is a purely motor nerve derived from the ventral rami of the cervical plexus that is readily accessible near the laryngeal complex. It has an ideal diameter for nerve to nerve anastamosis and its sacrifice produces little morbidity.Types of laryngeal reinnervation includeNeuromuscular pedicleNerve-nerve anastamosisThese may be combined with injection laryngoplasty until reinnervation takes place.
37Treatment – Laryngeal Reinnervation Nerve muscle pedicle (NMP)Nerve with portion of motor units transferred to a denervated muscle.Thyrotomy performed to place the NMP to the lateral cricoarytenoid muscle.Tucker et al. reported improvement in voice quality and restoration of adduction.1In the nerve muscle pedicle procedure, the nerve is transferred with a portion of its intact motor units. Reinnervation depends partly on the ability of the transplanted axons to reach receptive sites on the recipient muscle fibers and partly on the ability of the muscle fibers to accept innervation from foreign nerves.In this procedure,NMP harvested using branch of ansa cervicalis and 2-3 mm block of omohyoid and placed into the LCA via a thyrotomy.The thyroid cartilage on the denervated side is exposed, and the lower half of the perichondrium of the thyroid cartilage is incised in the midline. A posteriorly based perichondrial flap exposing the lower half of the thyroid ala is created. A block of thyroid cartilage is removed from this area, leaving the underlying perichondrium and the inferior margin of the thyroid cartilage intact. The inner perichondrium is incised to expose the denervated LCA muscle and the NMP sutured in place.Although Tucker et al. reported improvement in voice quality and restoration of adduction, the widespread use of NMP is limited.Tucker et al. Long-term results of nerve-muscle pedicle reinnervation for laryngeal paralysis. Ann Otol Rhinol Laryngol 1989;98:
38Treatment – Laryngeal Reinnervation Ansa cervicalis to RLNProvides weak tonic innervation to intrinsic laryngeal musclesAdv: Extralaryngeal, no permanent implant material, does not affect subsequent proceduresDisadv: Deeper dissection, requires intact nerves , delay in voice improvementCrumley reported improved vocal quality and restoration of the mucosal wave.1Lorenz et al. reported improved vocal quality as well as glottic closure and vocal fold edge straightening.2Although other reinnervation techniques, including from the phrenic, preganglionic sympathetics, and hypoglossal nerves have been described, the ansa cervicalis to RLN reinnervation has been most described. Ipsilateral or contralateral ansa may be used.Provides weak tonic innervation to intrinsic laryngeal muscles to increase bulk and tone.Reinnervation of the TA restores tension resulting in a more normal mucosal wave.Reinnervation of PCA and LCA stabilizes the arytenoid and prevents inferior displacement of the vocal process, thus providing a more symmetric position relative to the opposite side.Procedure:Incision made below level of cricoid usually at level of thyroidectomy incision.After both nerves are identified and the distal RLN is confirmed to be intact, the ansa and RLN are transected. Each nerve should be divided inferiorly enough to allow a tension-free anastomosis.A tunnel deep to the sternohyoid and sternothyroid muscles connects the two operative sites and facilitates the anastomosis.Advantages of this procedures is that it provides bulk and tone to the denervated cord and improves position of the paralyzed vocal cord without placement of any permanent implant material. In addition, the procedure is extralaryngeal and does not affect subsequent use of injection or thyroplasty.Disadvantages are thatIt requires a deeper level of dissection in the neck, with increased OR time compared to thyroplasty or vocal fold injection.It requires intact ansa and RLN distal stump which may be difficult in a previously operated neck.In addition, the possibility of spontaneous recovery is eliminated with the division of the RLN before anastamosis, thus necessitating at least a 12 month waiting period from the onset of paralysis.Finally, there is a delay of 6-9 months before substantial improvement in voice occurs. As a result, injection laryngoplasty with a temporary material may be combined with this procedure until reinnervation takes place.Crumley reported improved vocal quality and restoration of the mucosal wave.1More recently, in a retrospective review, Lorenz et al. found an improvement in voice quality, specifically improved severity, roughness, breathiness, and strain and improvement in glottic closure and vocal fold edge up to 18 months post op.Crumley. Update: ansa cervicalis to recurrent laryngeal nerve anastomosis for unilateral laryngeal paralysis. Laryngoscope Apr;101(4 Pt 1):Lorenz et al. Ansa cervicalis-to-recurrent laryngeal nerve anastomosis for unilateral vocal fold paralysis: experience of a single institution. Ann Otol Rhinol Laryngol Jan;117(1):40-5.
39ConclusionUnilateral vocal cord paralysis affects quality of life and may cause significant morbidityThorough evaluation is mandatory to determine etiology if initially unclearMany treatment options are available which are tailored to patient
41References Cummings: Otolaryngology: Head & Neck Surgery, 4th ed. Bailey: Head and Neck Surgery – Otolaryngology, 4th ed.Rubin et al. Vocal Fold Paresis and Paralysis. Otolaryngol Clin N Am Oct; 40(5):Urquhart et al . Idiopathic vocal cord palsies and associated neurological conditions. Arch Otolaryngol Head Neck Surg Dec;131(12):Brousseau et al. A rare but serious entity: nasogastric tube syndrome. Otolaryng Head Neck Surg Nov;135(5):Rosenthal et al. Vocal Fold Immobility: A Longitudinal analysis of Etiology Over 20 Years. Laryngoscope Oct;117(10):Merati et al. Diagnostic testing for Vocal Fold Paralysis: Survey of Practice and Evidence-Based Medicine Review. Laryngoscope Sept; 116:Terris et al. Contemporary evaluation of unilatereal vocal cord paralysis. Otolaryngol Head Neck Surg Jul;107(1):84-90.MacGregor et al. Vocal Fold palsy: a re-evaluation of investigations. J Laryngol Otol. 1994;108:ElBadawey et al. Prospective study to assess vocal cord palsy investigations. Otolaryng Head Neck Surg 2008; 138:Munin et al. Laryngeal electromyography: diagnostic and prognostic applications. Otolaryngol Clin North Am Aug;33(4):Sataloff et al. Practice parameter: laryngeal electromyography (an evidence-based review). Otolaryngol Head Neck Surg 2004; 130:Koufman et al. Diagnostic laryngeal electromyography: The Wake Forest experience Otolaryngol Head Neck Surg Jun;124(6):603-6.Wang et al. Prognostic indicators of unilateral vocal fold paralysis. Arch Otolaryngol Head Neck Surg Apr;134(4): O’Leary et al. Injection Laryngoplasty. Otolaryngol Clin N Am 2006;39:43-54.Kraus et al. Arytenoid adduction as an adjunct to type I thyroplasty for unilateral vocal cord paralysis. Head Neck Jan;21(1):52-9.Mucullouch et al. Arytenoid adduction combined with Gore-Tex medialization thyroplasty. Laryngoscope Aug;110(8):Abraham et al. Complications of type I thyroplasty and arytenoid adduction. Laryngoscope Aug;111(8):Tucker et al. Long-term results of nerve-muscle pedicle reinnervation for laryngeal paralysis. Ann Otol Rhinol Laryngol 1989;98:Crumley. Update: ansa cervicalis to recurrent laryngeal nerve anastomosis for unilateral laryngeal paralysis. Laryngoscope Apr;101(4 Pt 1):Lorenz et al. Ansa cervicalis-to-recurrent laryngeal nerve anastomosis for unilateral vocal fold paralysis: experience of a single institution. Ann Otol Rhinol Laryngol Jan;117(1):40-5.