Airway Complications and Management after Thyroidectomy

1. Airway Complications and Management after Thyroidectomy Jose M. Soliz, M.D. Christiane Vogt-Harenkamp, M.D. UT AnesthesiologyGrand RoundsMarch 31st 2005

2. Case History 19 year old Hispanic female presents for a left hemithyroidectomy. The patient underwent a right hemithyroidectomy six weeks previously for a thyroid nodule. On final pathology report, the patient was noted to have papillary thyroid cancer.

3. Case History Medications: none Allergies: none Past medical history: none Past surgical history: right hemithyroidectomy six weeks prior. uneventful, no noted complications

4. Case History Family History: non-contributory Social History: denies etoh, smoking, drugs ROS: on day of surgery, patient denied any fever, rhinorrea, hoarseness, or sore throat. Does complain of three day history of non productive cough without fever which had about resolved on day of surgery.

5. Physical Exam General: thin, 55kg Airway: Mallampati Class I, >3 FBMO, >5cm TM distance, good neck extension and flexion CV: RRR, no murmurs rubs or gallops Respiratory: clear to auscultation Extremities: WNL

6. Perioperative Course Pre-induction: Versed, prophylactic antibiotic Induction: Propofol, Fentanyl, Lidocaine, Rocuronium Intubation: Grade I view, 7.0 armored ETT placed with cuff inflated, non traumatic, 1 attempt Surgical course: uneventful, minimal blood loss Extubation: patient had four twitches, reversed, spontaneously breathing, positive hand grasp, eye opening on command

7. Extubation Cuff deflated, tube pulled. Patient began breathing low tidal volumes with audible stridor. Differential Diagnosis? What to do next?

8. Post-Extubation Patient desaturates to high 80’s low 90’s. Positive pressure applied with jaw lift. Assisted ventilation possible with movement of adequate tidal volumes. O2 sats return to 100%. Patient is then able to spontaneously move adequate tidal volumes with continued audible stridor and jaw lift.

9. Post-Extubation • Decision was made to deepen patient with sevoflurane while maintaining spontaneous ventilation. • DL performed by anesthesiology team and surgical attending. • Both vocal cords in paramedian position with no movement of Right vocal cord, and minimal movement of Left vocal cord with passive expiration, laryngeal and cord edema noted. • Surgeon sprays vocal cords and larynx with racemic epinephrine. Stridor continues. • ENT consulted intraoperatively, noted the above findings

10. Post-Extubation Plan • Plan: re-intubate patient with smaller diameter tube 6.0, start high dose steroids. Transport patient intubated and sedated to ICU • Plan for three days of high dose steroids • Trial of extubation and DL in OR, with ENT present for examination and possible tracheostomy. • Three days later, after EUA by ENT, findings of laryngeal edema had resolved, but right true vocal cord paralysis, and left true vocal cord paresis were unchanged and surgical airway was performed • Patient later discharged home with tracheostomy, was decannulated 2.5 months later with return of adequate cord function

11. Airway Complications and Management after Thyroidectomy Outline • Anatomy • Complications and management • Intubation related and post-op complications • Diagnosis and prevention • Therapeutic measures • Take home message • Focus on laryngeal nerve palsies

12. Anatomy

13. Airway Complications and Management after Thyroidectomy Anatomy of the Larynx • Begins at base of tongue, ends at beginning of trachea • Anterior to esophagus, extends from C5 to C6 (adults) and C3 to C4 in children • Houses vocal cords: voice generation; they extend from arytenoid cartilages posteriorly to thyroid cartilage anteriorly • Functions as valve: open during respiration, half open and modulated during phonation, closed during swallowing and before coughing

14. Airway Complications and Management after Thyroidectomy Anatomy of the Larynx • Consists of 9 cartilages (thyroid frontal, cricoid =complete ring, epiglottis, arytenoids, cuneiformes, corniculates) and • 4 joints plus fibro-elastic membranes, muscles and mucous membranes • Connects and separates oral cavity with / from airway / esophagus respectively • superior laryngeal artery as branch of sup. thyroid artery from external carotid artery; inferior laryngeal artery from thyro-cervical trunk and subclavian artery

15. Topographic Anatomy of Larynx and Trachea

16. Airway Complications and Management after Thyroidectomy Innervation of the Larynx • Above vocal cords: superior laryngeal nerve (CN X): • internal branch for sensory innervation of supra-glottic mucosa, • external branch with motor fibers to cricothyroid muscle • Below vocal cords:recurrent laryngeal nerve • motor innervation of intrinsic laryngeal muscles (abductors) , • sensory innervation of mucosa below vocal cords

17. Innervation

19. Airway Complications and Management after Thyroidectomy Intubation related complications • Tracheal tear • arytenoid subluxation (from placement of tube) can phonate, difficulty breathing • posterior lateral dislocation of arytenoids (from tube removal) can cause hoarseness, but good air movement • laryngeal edema • laryngeal nerve apraxias (can occur by compression of anterior ramus of RLN by ETT cuff. May lead to temporary unil. or bil RLN palsy • long term intubation: tracheomalacia, scarring, granuloma

20. Airway Complications and Management after Thyroidectomy Incidence of respiratory complications at extubation and in the recovery room is greater than at intubation • Hematoma (0.79% -1.2%)→airway obstruction • Laryngeal edema (0.19%)→airway obstruction • Hypoparathyroidism, temp.: 0.9-8.3%, perm.: <1.7%→ stridor, hypocalcemia • Dysphagia (1.4%) • Infection (0.3%) • Tracheomalacia (Rosato L. et al. World J Surg. 2004 Mar;28(3):271-6. Hermann M. et al. Ann Surg. 2002 Feb;235(2):261-8 Kark AE. et al Br Med J (Clin Res Ed) 1984 Nov 24;289(6456):1412-5)

21. Airway Complications and Management after Thyroidectomy • Unilateral recurrent laryngeal nerve palsy, • temp.: 0.2 - 7%, 50-93% of cases, • perm.(after 6-24 months): 0.2 -1.6% • of note: 1.9% of patients without and 3% of patients presenting with carcinoma of the thyroid have unilateral/ ipsilateral recurrent laryngeal nerve palsy pre-operatively)→ hoarseness, impaired coughing, aspiration; 30-50% without symptoms! (Rosato L. et al. World J Surg. 2004 Mar;28(3):271-6. Hermann M. et al. Ann Surg. 2002 Feb;235(2):261-8 Kark AE. et al Br Med J (Clin Res Ed) 1984 Nov 24;289(6456):1412-5)

22. Airway Complications and Management after ThyroidectomyRecurrent laryngeal nerve palsy - Unilateral • Symptoms: • hoarseness • breathlessness • ineffective cough • aspiration • glottic incompetence Farling, P.A. Thyroid Surgery. British Journal of Anaesthesia, 2000, Vol. 85, No.1, 15-28

23. Airway Complications and Management after Thyroidectomy • Bilateral recurrent laryngeal nerve palsy (0.4% -1.9%)→ airway obstruction • Damage to the superior laryngeal nerve (3.7-25%)→ voice alteration (Rosato L. et al. World J Surg. 2004 Mar;28(3):271-6. Hermann M. et al. Ann Surg. 2002 Feb;235(2):261-8 Kark AE. et al Br Med J (Clin Res Ed) 1984 Nov 24;289(6456):1412-5)

24. Airway Complications and Management after ThyroidectomyRecurrent laryngeal nerve palsy • Injury can occur by a number of mechanisms such as ischemia, contusion, entrapment, and actual transection • Higher risk of damage for malignancy and secondary operations • Anatomic variability and distortions will increase the risk of nerve injury Farling, P.A. Thyroid Surgery. British Journal of Anaesthesia, 2000, Vol. 85, No.1, 15-28

25. Airway Complications and Management after Thyroidectomy RISKFACTORS FOR RECURRENT LARYNGEAL NERVE DAMAGE • No or incomplete dissection and exposure of recurrent laryngeal nerve (Visualization required along the distance between branching of inferior thyroid artery and entry of nerve into cricothyroid cartilage) • Non- recurrent laryngeal nerve (anatomical variation, 0.25-0.79%, only on right side) • Thyroid cancer • Total thyroidectomy (permanent nerve damage) • Re-do surgery (recurrence or cancer) • Sub-sternal goiter • Ligature of the inferior laryngeal artery (Friedrich T. et al Zentralbl Chir. 2000;125(2):137-143 Defechereux T. et al Acta Chir Belg.2000 Mar-Apr;100(2):62-67)

26. Airway Complications and Management after Thyroidectomy RISKFACTORS FOR RECURRENT LARYNGEAL NERVE DAMAGE The risk of recurrent laryngeal nerve palsy with total thyroidectomy for cancer or in re-do surgery for recurrence of goiter is about 10 times higher than for one-time surgery in benign disease. (Friedrich T. et al Zentralbl Chir. 2000;125(2):137-143 Defechereux T. et al Acta Chir Belg.2000 Mar-Apr;100(2):62-67)

27. Airway Complications and Management after Thyroidectomy Prevention • Pre-operative laryngoscopy: • 1.9% of patients without and 3% of patients presenting with carcinoma of the thyroid have unilateral/ ipsilateral recurrent laryngeal nerve palsy pre-operatively • Complete dissection and exploration of recurrent laryngeal nerve during surgery • visualization required along the distance between branching of inferior thyroid artery and entry of nerve into cricothyroid cartilage) • Awareness of anatomical variations

28. Airway Complications and Management after Thyroidectomy • Prevention • Continuous RLN monitoring may be useful in certain cases, but time consuming, requires spontaneous ventilation, and incidence of false negatives. Also controlled trials have shown no statistical reduction in paralysis, paresis, or total injury rates to the RLN • May perform deep extubation with spontaneous breathing to observe vocal cord movement. • Farling, P.A. Thyroid Surgery. British Journal of Anaesthesia, 2000, Vol. 85, No.1, 15-28 • Robertson ML, Steward DL, Gluckman JL, et al. Continuous laryngeal nerve integrity monitoring during thyroidectomy: does it reduce risk of injury? Otolaryngology Head and Neck Surgery. 2004 Nov; 131(5):596-600.

29. Airway Complications and Management after Thyroidectomy Therapeutic strategies for unilateral and bilateral recurrent laryngeal nerve palsy Unilateral: • spontaneous recovery of function (40%) • logopedic treatment • electro therapy • surgical (medialization of vocal cords) Joshua B. et al Isr Med Assoc J 2004 Jun;6(6):336-8 Tanaka S. et al Laryngoscope 2004 Jun;114(6):1118-22 Cheng SC. Et al Zhonghua Er Bi Yan Hou Ke Za Zhi 2004 Aug;39(8):464-8)

30. Airway Complications and Management after Thyroidectomy Therapeutic strategies for unilateral and bilateral recurrent laryngeal nerve palsy Bilateral: • Reintubation (if paralyzed in para-median position • Tracheostomy • Surgical • endoscopic posterior ventriculocordectomy, • nerve decompression from ligatures or scar tissue, asap! • glottic widening procedures after 6-9 months Joshua B. et al Isr Med Assoc J 2004 Jun;6(6):336-8 Tanaka S. et al Laryngoscope 2004 Jun;114(6):1118-22 Cheng SC. Et al Zhonghua Er Bi Yan Hou Ke Za Zhi 2004 Aug;39(8):464-8)

31. Airway Complications and Management after Thyroidectomy Therapy of other Complications (incl. Intubation related Damage ) • Hematoma • immediate: reintubation, evacuation, hemostasis • delayed: evacuation, hemostasis, and (awake) re-intubation, tracheostomy • Laryngeal edema • Reintubation with small ETT, steroids, extubation after 24 or 48 hours with leak test and over airway exchange catheter • Scarring • Laser ablation of arytenoid scar tissue • Tracheomalacia: • Re-intubation • surgical correction

32. Airway Complications and Management after Thyroidectomy Therapy of other Complications (incl. Intubation related Damage ) • Apraxia of recurrent laryngeal nerve with temporary unil. or bil RLN palsy (compression of anterior ramus of RLN by ETT cuff) : • Reintubation with smaller tube, • racemic epinephrine inhalation, • Tracheostomy • NOTE: measure cuff pressures, or inflate cuff only to negative leak

33. Take home message • Identification of recurrent laryngeal nerve injury postop based on clinical symptoms is not reliable. • Up to 1/2 of patients with RLN damage may have no or minimal voice changes post op with a unilateral RLN lesion. • Post -op voice changes can occur without nerve lesion, may be result of superior LN damage or intubation alone • In redo or cancer related thyroid surgery, request pre-op examination by ENT prior to surgery • Farling, P.A. Thyroid Surgery. British Journal of Anaesthesia, 2000, Vol. 85, No.1, 15-28 • Robertson ML, Steward DL, Gluckman JL, et al. Continuous laryngeal nerve integrity monitoring during thyroidectomy: does it reduce risk of injury? Otolaryngology Head and Neck Surgery. 2004 Nov; 131(5):596-600.