|HOW I DO IT
|Year : 2011 | Volume
| Issue : 2 | Page : 66-69
Management of bilateral abductor palsy: Posterior cordectomy with partial arytenoidectomy, endoscopic approach using CO 2 laser
Department of Laryngology, Deenanath Mangeshkar Hospital, Pune, Maharashtra, India
|Date of Web Publication||19-Sep-2011|
Department of Laryngology, Deenanath Mangeshkar Hospital, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
| Abstract|| |
The treatment of bilateral immobile vocal cords (BAP) is a balance between phonation, airway and swallowing. Various techniques of endoscopic approach for the treatment of bilateral vocal fold immobility have been proposed and have been modified by various surgeons. Trans oral CO 2 laser endoscopic arytenoidectomy has become the most common method for its management. CO 2 laser is arguably the most appropriate tool for cordectomy with the advantage of increased precision, better hemostasis and minimal tissue handling. We describe the procedure of posterior cordectomy with partial arytenoidectomy using trans oral CO 2 laser for management of BAP. The present modality of preservation of part of shelf of arytenoid and use of laser in super pulse mode contribute to good results with minimum complication
Keywords: Bilateral abductor palsy, CO 2 laser, cordectomy
|How to cite this article:|
Gandhi S. Management of bilateral abductor palsy: Posterior cordectomy with partial arytenoidectomy, endoscopic approach using CO 2 laser. J Laryngol Voice 2011;1:66-9
| Introduction|| |
Bilateral immobile vocal cord due to bilateral abductor palsy leads to respiratory distress that occasionally can become life threatening. Vocal cords are immobilized either due to palsy or fixation. Though their voice quality is not affected as the vocal cords are in adduction with an inability to abduct, the patient does have stridor which gets worse on exertion or during respiratory infection.
Various etiologies known to cause this condition are neck surgery (predominantly thyroid), trauma, neurological disorders and laryngeal malignancies. 
The symptomatic treatment for this condition is a balance between phonation, airway and swallowing. Surgeons have long been searching for techniques to safely widen the glottic airway in patients with bilateral vocal cord paralysis without detracting from vocal quality and/or causing aspiration. Surgical methods were designed to attain good respiration, phonation and swallowing. For last 15 years, trans oral carbon dioxide (CO 2 ) laser endoscopic arytenoidectomy has perhaps become the most common method.
Since 1922 when there was no alternative to tracheostomy to present times when there are multiple options available, the treatment of bilateral immobile cords has evolved with time. The method adopted by Chevalier Jackson introduced of ventriculocordectomy, where by the entire vocal cord and ventricle was excised,  created an excellent airway but resulted in breathy voice. Sub mucosal resection of vocal fold proposed by Hoover resulted in excessive scarring and thus leading to glottic stenosis and post operative dysphonia. 
Procedures on arytenoids included extra laryngeal arytenoidectomy  in which arytenoid cartilage was freed from all its muscular and ligamental attachments except the vocal muscle. In lateralization procedure, the arytenoids are fixed laterally to the thyroid ala. This was modified by fixation of the corresponding vocal fold in order to conserve a good glottic opening. 
Reports of laryngofissure with arytenoidectomy with lateralization of the vibrating portion of vocal cord with stainless steel suture creating glottic airway of 4 to 6 mm at its posterior aspect are also documented. 
Various techniques of endoscopic approach for the treatment of bilateral vocal fold immobility have been proposed and have been modified by various surgeons. , Remacle et al., and Plouin-Gaudon et al., described their results of subtotal arytenoidectomy with CO 2 laser. , Oswal et al., described their results of endoscopic laser surgery for bilateral immobile cords on basis of respiration, phonation and swallowing. 
CO 2 laser is arguably the most appropriate tool for cordectomy with the advantage of increased precision, better hemostasis and minimal tissue handling. In the present article, I describe the use of trans-oral CO 2 laser for managing cases with compromised airway due to bilateral immobile vocal cords by a Sub-total arytenoidectomy with posterior cordectomy Though the procedure itself may be performed on any such case, there are certain situations where the surgery should not be done. These include patients with concurrent pulmonary, neurological and malignant disease. A simultaneous lesion compromising the airway like a sub-glottic stenosis should always be looked for since it makes the surgery unsuitable. Also in the pediatric age group with age less than 12 years, we prefer not to do this surgery.
| Pre-Operative Work Up|| |
A detailed history is recorded to identify the possible etiology. Most of the patients either present with stridor or have distressed breathing of exertion or during sleep. Each patient is investigated with endoscopy, radiology and pulmonary function test (PFT). All patients are examined by flexible endoscopy, digital videostroboscopy and with digital high speed camera to evaluate the entire upper airway and to measure the glottic chink. A high resolution CT imaging of the neck and mediastinum is done to rule out any external cause.
Anti reflux management was started in all the patients three weeks before surgery and continued for 12 weeks following surgery.
The endotracheal tubes used should be laser safe, and are available in various forms. Commonly used ones are the Oswal-Hunton uncuffed metal tube, the Mallinckrodt tube (stainless steel endotracheal tube available as uncuffed and cuffed), the Rush Kernen Latex tube which has a double cuff, and the Laser-Shield® tube by Medtronics Xomed company. Patients with tracheostomy are anesthetized using red rubber endotracheal tube through the tracheal stoma. A wet cottonoid pack is then placed in the subglottis to protect the endotracheal tube. The cuff is inflated with normal saline tinted with methylene blue in order to reveal any possible damage during the course of surgery. The patient's face is protected by large, moist compresses. The intubation tube is removed toward the end of the surgery to clear up the posterior most part of the vocal cord and arytenoids. Jet ventilation is subsequently used during this part of the surgery.
The choice of anesthetic technique is determined as per the findings. Majority of these patients presented with tracheostomy. In these patients, laser safe tube was used for anesthesia, with use of wert cottonoid around it. Others were anesthetized with combination of intubation and jet ventilation High frequency jet ventilation was used as it allows unimpeded view of the glottis.
| Operative Technique|| |
The suspension laryngoscope is used for the complete exposure of glottis especially of the posterior commissure. By direct laryngoscopy and use of 70 Hopkins telescope, the endolarynx is inspected. The mobility of crico-arytenoid joint is checked with a probe. 0endoscope of 4.6 mm diameter is used to examine the complete airway and to rule out any associated airway pathology
A CO 2 laser is used, coupled with Acublade® , a automated scanning device. This laser is coupled to an operating microscope (Karl Zeiss) for surgery. Laryngeal micro surgical instruments specially adapted for laser surgery ith suction and cautery attachments are used. Diode laser (Diomed UK) is used as a complementary laser system in cases of bleeding in posterior glottis.
Subtotal/partial arytenoidectomy with posterior cordectomy
The surgery starts with horizontal laser incision on the free edge of vocal cord just anterior to the vocal process. The section must be completed in order to obtain retraction of the membranous vocal fold to the front. The incision is initially marked and extended laterally in the paraglottic space up to 4 mm toward the thyroid cartilage as shown in the picture. After grasping the vocal process, the cutting is continued posteriorly and medially to include the laryngeal slope of the body of the arytenoid in excision. The portion so excised includes the vocal process, posterior third of the true cord, posterior part of ventricular fold and medial part of body of arytenoid. Ideally this procedure creates up to 6 mm of transverse opening in the posterior glottis, adequate for most patients without undue risk of prolonged aspiration [Figure 1],[Figure 2],[Figure 3],[Figure 4].
The settings on the laser machine we use are as follows. CO 2 laser is used in Acublade® mode with 0.5 to 2.0 mm length, 0.2 to 0.5 mm depth and 8 W of power for subtotal arytenoidectomy, 5 W of power for posterior cordectomy. Laser application is done in continuous mode with super-pulse. Flash scanner mode with 0.7 mm diameter 2 to 2.5 W of power is used in continuous mode for vaporization and reduction of the posterior shelf of the arytenoids to minimize or prevent aspiration.
A 2 mm posterior shell of the arytenoid cartilage is preserved to prevent aspiration [Figure 1]. This is more easily performed in super pulse mode because of its superior sectioning effect with less carbonization, which can mask the limits of the tissues to be spared. If the posterior shell looks too thick, it can be made thinner by vaporization with scanner mode of CO 2 laser. The procedure is completed by splitting of the joint between the cricoid cartilage and the resected part of the arytenoid cartilage body. If necessary, hemostasis of the arytenoid artery is achieved by electrocoagulation via the monopolar cautery attachment of microforceps / adjuvant use of Diode laser.
The surgical procedure usually lasts for 25 to 30 min. After the resection of the arytenoid the surgical site is covered with neuro surgical cottonoid with 2 ml of mitomycin-C (1 mg/ml) for 2 min to prevent fibrosis. The bed is then covered with fibrin glue to prevent the formation of granuloma. During surgery, antibiotics (cefotaxim) and steroids (dexamethasone) are administered intravenously. Upon awaking, non-tracheostomy patients are extubated in OT room.
| Post Operative Management|| |
Postoperatively, the patients are kept in intensive care unit for 24 h for observation. The patients are observed for respiratory difficulties due to possible surgical edema. All patients receive post operative therapy including broad spectrum antibiotics for 7 days, nebulization with steroids and mucolytic agent. Anti reflux treatment is given for 12 weeks. Patients do have some dysphonia post-operatively but usually, useful phonation may be achieved in most cases with formation of neocord.
Almost all cases show transient aspiration of both liquids and semi-solids. Though aspiration for semi-solids improves in first 24-48 h, the same for liquids may continue for another day or two. However none of these cases show prolonged aspiration. Besides aspiration, the possible known complications include granuloma formation, posterior glottal webbing, and insufficient airway requiring revision surgery.
Benefits of this technique
Subtotal arytenoidectomy as practiced by us has shown excellent results in our centre [Figure 5] and [Figure 6]. The procedure as proposed here is performed in 25-30 min and does not need tracheostomy prior to surgery. This is also due to the fact of availability of superpulse mode that increases the cutting effect reducing the thermal effect and risk of edema. None of the operated patients have required re-intubation due to glottic edema; however, we do keep the patient in ICU for 24 h for observation. CO 2 laser definitely makes the surgery easier as compared to that done by use of cold instruments especially in terms of bloodless fields at the level of arytenoid artery.
|Figure 5: Preoperative image of glottic inlet showing bilateral abductor palsy|
Click here to view
This technique is a modified version as that described by Ossoff et al., in the sense that laser is used in super pulse continuous mode. This reduces the surgical time. A posterior cartilaginous shelf is preserved and this allows good stability of arytenoid region.
This also reduces the surgical time, postoperative hospital stay. The respiratory functions are also better after this procedure. Patient does have some dysphonia, but this can be minimized by preservation of as much as possible of the vibrating portion of the vocal cord.
| Conclusion|| |
CO 2 laser partial arytenoidectomy by trans oral endoscopic route is an excellent and less morbid alternative modality to open procedure. The present modality of preservation part of shelf of arytenoid and use of laser in super pulse mode contribute to the good results with minimum complication.
| References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]