The Incidence of Recurrent Laryngeal Nerve Damage Following

The Incidence of Recurrent Laryngeal Nerve Damage Following an Anterior Cervical Spine OperationBy: Brian Purcell, BSN, SRNAUPMC Hamot Medical Center School of Anesthesia/Gannon UniversityRecurrent Laryngeal Nerve

Recurrent Laryngeal NerveBranch of the Vagus Nerve, Crainial Nerve X. Left recurrent laryngeal nerve passes at aortic arch. Provides sensory innervation to infraglottis (Trachea below the vocal cords)Provides motor innervation to all of the larynx except the cricothyroid muscle

Recurrent Laryngeal NerveInnervates all of the 1st set of Intrinsic Larynx Muscles. These muscles alter the size and shape of the larynx.Aryepiglottic- Pulls epiglottis down over larynxThyroepiglottic- Assists pulling epiglottis downOblique arytenoid- Pulls arytenoids togetherRecurrent Laryngeal NerveInnervates all of the 2nd set of intrinsic laryngeal muscles except the cricothyroid (External Superior Laryngeal Nerve)These muscles move the true vocal foldsThyroarytenoid- relaxes vocal cordsLateral Cricoarytenoid- adducts vocal cordsPosterior Cricoarytenoid- abducts vocal cordsTraverse Arytenoid- adducts vocal cordsVocalis- weak abduction of vocal cords

Recurrent Laryngeal NerveStimulation of Recurrent Laryngeal Nerve causes abduction, opening of the vocal cords.

Recurrent Laryngeal NerveDamage to Recurrent Laryngeal Nerve causes vocal cord adduction, closing.

Recurrent Laryngeal NervePartial damage to Recurrent Laryngeal nerve on one side will cause the cord on the same side to shut, resulting in a deterioration of voice quality Unilateral damage usually does not compromise airway function, but airway protection against aspiration may be compromised.

Recurrent Laryngeal NerveBilateral damage to Recurrent Laryngeal Nerve will cause both vocal cords to shut. This results in stridor and respiratory distress. If the recurrent laryngeal nerve is completely severed, the vocal cords will partially close and will not move. Recurrent Laryngeal NerveSymptoms of Recurrent Laryngeal Nerve damageUnilateral: HoarsenessBilateral acute: Stridor, respiratory distressBilateral chronic: AphoniaBilateral damage and the patient will not be able to speak. Ask the patient to say e which implies continued vocal cord function. Bilateral damage may require re-intubation, Cpap may be effective for airway obstruction. 10Damage to Recurrent Laryngeal NerveWhat can cause damage to the Recurrent Laryngeal Nerve?LaryngoscopyIntubationLMA LesionsTraumaSurgical ProceduresLesions in the mediastinum may involve the recurrent laryngeal nerve. The patient may present with hoarseness and may potentially have airway management issues including difficult mask ventilation, intubation, and an increased risk of aspiration. 11Examples of Surgical Procedures that can Cause Damage to Recurrent Laryngeal NerveENTTHYROIDPARATHYROIDTRACHEAL RESECTIONNECK DISSECTION

Examples of Surgical Procedures that can Cause Damage to Recurrent Laryngeal NerveThoracicLobectomyPneumonectomyLung ResectionMediastinoscopy

Examples of Surgical Procedures that can Damage Recurrent Laryngeal NerveVascular SurgeryCarotid EndartectomyExamples of Surgical Procedures that can Cause Damage to Recurrent Laryngeal NerveGeneral SurgeryEsophagostomy/EsophagectomyEsophageal Diverticulectomy

Examples of Surgical Procedures that can Cause Damage to Recurrent Laryngeal NerveNeurosurgeryAnterior Cervical FusionInvolves anterior neck dissection and retraction of the soft tissue that gives exposure to the anterior vertebral column.

Anterior Cervical Spine Surgery and Recurrent Laryngeal Nerve DamageRetraction InjuryFor this surgery, Jaffe and Samuels report a 5% incidence. The exact cause recurrent laryngeal nerve injury is not known, but it is hypothesized that compression of the recurrent laryngeal nerve within the endolarynx leads to injury(Apfelbaum, Kriskovich & Haller, 2000)Anterior Cervical Spine Surgery and Recurrent Laryngeal Nerve DamageWhat can be done to decrease or prevent the incidence? Manipulate ETT cuff after retractor placementUse the least amount of air possible in the ETT cuff to maintain a seal Side of surgical approachReplace Retractors Monitor Recurrent laryngeal nerve during surgeryManipulate ETT cuff after retractor insertionApfelbaum, Kriskovich & Haller in 2000 studied the relationship between deflating cuff after retractor placement and re-inflating after 5 seconds. Allows ET tube to re-center within the larynxThe rate of temporary paralysis decreased from 6.4% to 1.69% using the described maneuver

the retractor displaces the larynx against the shaft of the endotracheal tube with impingement on the vulnerable intralaryngeal segment of the recurrent laryngeal nerve. 19Manipulate ETT cuff after retractor insertionAudu, et al. in 2006 did not find statistical significance in their study as to the use of the above described method. Some surgeons use the method some do not Use just the amount of air required to create a seal in the Endotracheal tube cuffAudu, et al describe this method as the just seal method.the ETT was insufflated using the just seal method as follows: With the ETT cuff deflated, positive pressure (2025 cm H2O) was generated in the breathing circuit while listening for an air leak around the ETT. The cuff was then insufflated with air until the leak was obliterated.

The goal was to keep the cuff pressure under 20 while still maintaining a seal. In some cases this was not possible. 21Use just the amount of air required to create a seal in the Endotracheal tube cuffAudu et al in 2006 did not find statistical significance in decreasing incidence of vocal cord paralysis associated with recurrent laryngeal nerve damageJung and Schramm published in 2010 did find significance in in decreased incidence of paralysis with lower ETT cuff pressuresSide of surgical approachJung and Schramm (2010) report that in conjunction with maintaining low ETT cuff pressures, the left side approach reduced the incidence of vocal cord paralysisReplace RetractorsRackesh et al. (2010) conducted a study that found cuff pressure in general may be the cause of vocal cord paralysis. Conclusions were to create a just seal and possibly institute intermittent release of the retractors which would keep the cuff pressures at an acceptable levelDuring the study, the researchers found that without intervention, cuff pressures could reach as high as 168% of basline. 24Monitor Recurrent Laryngeal Nerve Intra-operativelyTisdall, M., Henn, C., & Dorward, N. (2010) study on 19 patients using vagal/recurrent laryngeal nerve stimulation to monitor the integrity of the recurrent laryngeal nerve. With small sample size, researchers concluded that intraoperative monitoring may potentially reduce the incidence of recurrent laryngeal nerve palsy.

Monitor Recurrent Laryngeal Nerve Intra-operatively

Monitor Recurrent Laryngeal Nerve Intra-operativelyStimulation monitoring similar to that used in Thyroid surgery, where such monitoring is manditory Monitoring identifies the recurrent laryngeal nerve, and can identify areas of concern which can be avoided to reduce recurrent laryngeal nerve injuryTisdall, M., Henn, C., & Dorward, N. (2010)

Conclusions Recurrent Laryngeal Nerve is Branch of Cranial Nerve X (Vagus Nerve)Left recurrent laryngeal nerve passes at the aortic archProvides sensory innervation to infraglottis (Trachea below the vocal cords)Provides motor innervation to all of the larynx except the cricothyroid muscle

ConclusionsStimulation of Recurrent Laryngeal Nerve causes abduction, opening of the vocal cords. Damage to Recurrent Laryngeal Nerve causes vocal cord adduction, closing. Unilateral damage causes vocal cord on same side as the damage to close. This can result in hoarseness and the inability to protect against aspiration.

ConclusionsBilateral damage will cause both cords to close and will result in respiratory distressDamage to recurrent laryngeal nerve during anterior cervical surgery is thought to be caused by compression of the caused by retractor placement. Recurrent laryngeal nerve damage is the most common ENT complication associated with anterior cervical procedures.

ConclusionsMethods of preventing recurrent laryngeal nerve injury:Manipulate the endotracheal tube cuff after retractor placement. Create a just seal with ETT cuffPossibly perform surgery from left side.Stimulation monitoring of recurrent laryngeal nerve

ConclusionsStill no concrete standard of care in preventing recurrent laryngeal nerve damage. More study and research needs to be completed to create a concrete standard of care. References Apfelbaum, R., Kriskovich, M., & Haller, J. (2000). On the incidence, cause, and prevention of recurrent laryngeal nerve palsies during anterior cervical spine surgery. Spine, 25(22), 2906-2912. Audu, P., Artz, G., Scheid, S., Harrop, J., Albert, T., Vaccaro, A., & ... Rosen, M. (2006). Recurrent laryngeal nerve palsy after anterior cervical spine surgery: the impact of endotracheal tube cuff deflation, reinflation, and pressure adjustment. Anesthesiology, 105(5), 898-901.

References Jaffe, R., & Samuels, S. (2009). Anesthesiologist's manual of surgical procedures. (4th ed.). Philadelphia: Lippincott, Williams & Wilkins, a Wolters Kluwer business.Jung, A., & Schramm, J. (2010). How to Reduce Recurrent Laryngeal Nerve Palsy in Anterior Cervical Spine Surgery: A Prospective Observational Study. Neurosurgery (67)1, 10-15References Rakesh, G., Girija,R., Parmod, B., Hemansh, P., Manish, M. (2010). Clinical Investigation Effects of Retractor Application on Cuff Pressure and Vocal Cord Function in Patients Undergoing Anterior Cervical Discectomy and Fusion. Indian Journal of Anaesthesia (54)4, 292-295. DOI: 10.4103/0019-5049.68370Tisdall, M., Henn, C., & Dorward, N. (2010). Intra-operative Recurrent Laryngeal Nerve Stimulation During Anterior Cervical Discectomy: A Simple and Effective Technique. British Journal of Neurosurgery (24)1, 77-79. DOI: 10.3109/02688690903398459