Medical Therapy
In rheumatoid arthritis involving the larynx, treatment options depend on the chronicity of the disease. In general, acute cricoarytenoid (CA) rheumatoid arthritis is treated medically with anti-inflammatory and analgesic medications (with or without systemic steroid therapy). Adjunctive vocal rest, local heat, and humidification may prove helpful. Periarticular local steroid injections have helped in ameliorating acute joint dysfunction.
Treatment of infectious causes of joint fixation requires appropriate antimicrobial therapy for the infecting agent.
Surgical Therapy
Surgical procedures addressing arytenoid fixation can be organized into 2 categories. Techniques in the first group attempt to mobilize the cricoarytenoid (CA) joint in a manner analogous to joint mobilizations in the limbs. For example, in joint fixation resulting from traumatic fracture or dislocation of the cricoarytenoid (CA) joint, expedient relocation of the displaced arytenoid appears to be the procedure of choice, similar to the treatment choice for a dislocated knee or shoulder. Techniques in the second group are based on the concession that the joint is irreparably fixed; they focus on improving the airway by alternative means. This second category also applies to causes of glottic airway restriction other than joint ankylosis. [8]
In 1986, Schaefer et al described a surgical procedure for mobilizing fixed cricoarytenoid (CA) joints. [9] This procedure was performed through a midline thyrotomy in which a superiorly based mucosal flap was elevated from the arytenoid and posterior commissure mucosa. The medial aspect of the cricoarytenoid (CA) joint was then explored, and adhesions in the joint space were lysed until the arytenoid was thought to gain passive mobility. The posterior glottis was expanded by advancing the mucosal flap. Finally, a modified endotracheal tube (Portex stent; Smiths Medical, Kent, United Kingdom) was secured in the glottis to temporarily support the arytenoids in a lateralized position; it was removed approximately 2-3 weeks after surgery during a brief endoscopic procedure.
This procedure was performed in 4 patients, and the cannula was later removed in 3. The authors strongly believed that early postoperative speech therapy improved the range of motion of the cricoarytenoid (CA) joint and, consequently, the final functional outcome.
Closed reduction can be effectively used to treat arytenoid dislocation, according to a prospective study by Lee et al, with early surgical intervention improving outcomes of this procedure. The study involved 22 patients with arytenoid dislocation, including 16 with anterior dislocation and 6 with posterior dislocation. Patients were treated with closed reduction with or without adjunct therapy (injection laryngoplasty or botulinum toxin administration), with the exception of one patient who recovered spontaneously. Of the treated patients, 18 regained arytenoid motion, accompanied by voice improvement, with recovery sustained 6 months postsurgery. The investigators also found that patients who underwent closed reduction within 21 days after the presumed dislocation event tended to have better restoration of arytenoid motion. [10]
A study by Cao et al found that 26 out of 33 patients with an arytenoid dislocation were satisfied with the outcome following closed reduction performed under local anesthesia, with significant improvements found in grade, roughness, breathiness, asthenia, maximum phonation time, self-assessed Voice Handicap Index, jitter%, shimmer%, normalized noise energy, and noise-to-harmonic ratio. [11]
Su et al reported that three patients with bilateral vocal fold immobility and mechanical fixation of the cricoarytenoid (CA) joint were successfully treated first with release of the joint via an external approach and then with exo-endolaryngeal suture lateralization. The joint-release procedure permitted the endolaryngeal mucous membrane to be preserved and allowed one patient to be decannulated and two individuals to experience dyspnea improvement. [12]
The second group of procedures is aimed at ameliorating static glottic airway insufficiency. Standard surgical approaches for treatment of adynamic glottic narrowing include transverse laser cordotomy, partial cordectomy, arytenoidectomy, lateralization procedures, and tracheotomy. Tracheotomy remains the criterion standard for maximizing the airway and preserving phonatory function.
In 1985, Ejnell et al reported their technique for mobilizing a fixed arytenoid with subsequent lateral fixation. [13] The object of this procedure, in contrast to the previously described method, is mobilization for the express purpose of arytenoid refixation in an advantageous position. The technique is performed by using jet ventilation or through a preexisting tracheostoma with the patient under general anesthesia. Coordinated endoscopy and external work are necessary to lateralize the true vocal fold. The arytenoid is initially positioned by passing a dilator through the glottis. Concurrent external lateral fixation is then affected by passing 2 needles through the thyroid lamina to create a suture loop around the vocal fold under direct vision of the endoscopist. The suture is then tied externally over the thyroid cartilage to maintain the position.
Cummings et al described a variation of this technique in 1999. [14] Their novel device and technique attempt to provide adjustable vocal-fold lateralization with a modified thyroplasty technique performed under flexible laryngoscopic visualization. Their design localizes the height of the true vocal fold by placing an external needle through a 1-cm, round window in the thyroid cartilage. A double helical cam device is then inserted medially to engage the soft tissue of the thyroarytenoid muscle lateral to the vocal process. The double-helix design allows the now-engaged tissue to be lateralized by independently backing out the outer cam and by drawing the inner helix and the vocal cord outward into the desired position. Subsequent adjustments after healing are theoretically feasible.
More recently, Rovo et al (2008) have described endoscopic arytenoid lateropexy for severe posterior glottic stenosis involving one or both cricoarytenoid joints. [15] This novel technique employs a specially designed, right-angled scythe for sharp division of the arytenoid and cricoid cartilage. Once scar lysis and cricoarytenoid (CA) joint mobility are achieved, a modified, steel sheath reinforced Lichtenberger endo-extralaryngeal needle carrier is used place a suture through the vocal process. The needle is then passed through the posterior aspect of the thyroid cartilage and secured through a small (about 0.5 cm) transcervical incision.
When complete, the arytenoid is in a posterior, lateral, and superior position which is felt to be a more physiologic position for the abducted arytenoid than prior lateralization techniques. This procedure is temporary and is intended to keep the posterior commissure tissues apart following CO2 laser lysis. Sutures are removed once re-epithelialization is complete. The authors demonstrate improvements in peak inspiratory flow, breathing at rest, and voice (once sutures were removed) in a large majority of patients. Additionally, radiographic evidence of transient postoperative aspiration resolved completely a few weeks after surgery.
The transverse laser cordotomy, which Kashima (1991) popularized, is designed to enlarge the posterior glottic airway while maintaining close opposition of the anterior true vocal folds for phonation. [16] A radial incision is made in the membranous vocal fold immediately anterior to the vocal process of the arytenoid. The resulting wedge-shaped defect in the posterior glottis is due to the anterior retraction of the thyroarytenoid muscle. In cricoarytenoid (CA) fixation, the magnitude of posterior glottic enlargement with cordotomy is entirely independent of arytenoid position and mobility, unlike with the techniques designed to achieve vocal-fold lateralization. The technical ease and minimal tissue destruction in this procedure are additional advantages. Cutting techniques other than the CO2 laser were more recently proposed to affect the same posterior cordotomy surgical defect.
Medial (partial) arytenoidectomy has also gained popularity because of its ability to directly enlarge the posterior respiratory glottis while minimally affecting the anterior phonatory glottis and preserving more of the native laryngeal structure in comparison to the total arytenoidectomy procedure. A comparison of postsurgical airway and phonatory outcomes for transverse cordotomy and medial arytenoidectomy to treat bilateral vocal-fold immobility demonstrated that the procedures yielded satisfactory and fairly comparable outcomes.
Endoscopic or open arytenoidectomy is another approach for enlarging the posterior glottic airway. The technique for endoscopic laser arytenoidectomy, as Ossoff et al elucidated in 1984, allows for the direct and relatively atraumatic ablation of the arytenoid cartilage without the morbidity of an external incision. [17] The addition of direct laser ablation to the armamentarium improved the relative ease of performance when compared to the endoscopic delivery and excision technique previously described by Thornell. Disadvantages of laser arytenoidectomy include the attendant airway risks of CO2 laser surgery, including airway fires and peripheral thermal damage.
As previously noted, tracheotomy remains the criterion standard for providing a safe adequate airway while maintaining native glottal tissue for phonatory function.
Complications
Potential complications of laser arytenoidectomy include the attendant airway risks of CO2 laser surgery, including airway fires and peripheral thermal damage. Postoperative aspiration is a potential complication of all airway-enlarging procedures, including tracheotomy. Furthermore, the extent of tissue alteration and/or destruction carries a proportional risk of degrading vocal quality. Therefore, the ideal surgical procedure is minimally destructive to the normal laryngeal anatomy and provides durable and reproducible airway and vocal function.
Outcome and Prognosis
The outcome and prognosis of cricoarytenoid (CA) fixation depends entirely on the etiology. However, given the relative infrequency of this diagnosis, it is not surprising that the literature contains no reports of clinical outcomes from large series of patients grouped by specific etiology and treatment strategies.
Future and Controversies
Given the infrequent reports of this entity, a routine workup of vocal-fold immobility is appropriate when it is encountered. Of no surprise, standard etiology-based treatment protocols for arytenoid fixation have yet to be established. Increased awareness of this diagnosis and careful attention to the natural history of patients ideally guide the physicians' therapeutic care plan.
The relationship of prolonged joint immobility to joint fixation is a disputed point. Intuition and reason suggest that prolonged immobility may result in cricoarytenoid (CA) joint ankylosis, as it does in other diarthrodial joints. However, histologic studies have failed to demonstrate this phenomenon in the cricoarytenoid (CA) joint. Possible reasons for this inconsistency may include the non–weight-bearing status of these joints and their potential for low-amplitude passive motion with respiratory airflow.
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Cartilages of the larynx, posterior view.