Postintubation interarytenoid adhesion

Characteristics of Experimental Recurrent Laryngeal Nerve Surgical Injury in Dogs

Objectives

We characterized various recurrent laryngeal nerve (RLN) injuries in dogs.

Methods

Sixteen dogs were classified as having complete injuries (transection) or incomplete injuries (ligation, half-section, and crush). The characteristics of nerve injuries were evaluated by endoscopic examination, laryngeal electromyography (LEMG), and histopathologic examination at 0 to 12 months after the injury.

Results

After the RLN injury, the average muscle fiber diameter and the average muscle bundle diameter of the affected muscles were decreased, and the average number of muscular cell nuclei per square inch increased. Fibrillation potentials were found 1 to 3 months after injury, and reinnervation potentials appeared 3 to 6 months after incomplete injury. For nerve transection and ligation, there was no reaction with LEMG instantly after injury involving vocal fold fixation. Vocal fold motion did not improve in members of the complete injury group, whereas all of the vocal folds in the members of the nerve ligation subgroup had limited activity in the later period. Various forms of vocal fold mobility were observed after injury in the half-section subgroup. Animals in the crush subgroup had normal EMG signals combined with abnormal LEMG signals with lower amplitudes after injury. Vocal fold fixation was not observed in this subgroup.

Conclusions

We found the causes of nerve injury, in order of decreasing severity, to be transection, ligation, half-section, and crush.

Diagnostic Laryngeal Electromyography: The Wake Forest Experience 1995–1999

BACKGROUND:

Laryngeal electromyography (LEMG) is a valuable diagnostic/prognostic test for patients with suspected laryngeal neuromuscular disorders.

OBJECTIVE:

To report our experience with diagnostic LEMG at the Center for voice Disorders of Wake Forest University and to evaluate the impact of LEMG on clinical management.

METHODS:

Retrospective chart review of 415 patients who underwent diagnostic LEMG over a 5-year period (1995–1999).

RESULTS:

Of 415 studies, 83% (346 of 415) were abnormal, indicating a neuropathic process. LEMG results altered the diagnostic evaluation (eg, the type of radiographic imaging) in 11% (46 of 415) of the patients. Unexpected LEMG findings (eg, contralateral neuropathy) were found in 26% (107 of 415) of the patients, and LEMG results differentiated vocal fold paralysis from fixation in 12% (49 of 415). Finally, LEMG results altered the clinical management (eg, changed the timing and/or type of surgical procedure) in 40% (166 of 415) of the patients.

CONCLUSIONS:

LEMG is a valuable diagnostic test that aids the clinician in the diagnosis and management of laryngeal neuromuscular disorders.

Laryngoscopy in Bilateral Vocal Fold Immobility: Can You Make a Diagnosis?

Objectives:

This study explores whether videoendoscopic findings and patient history help make the diagnosis in bilateral vocal fold immobility (BVFI).

Methods:

Medical records from 1995 to 2003 were searched to identify patients with posterior glottic stenosis (PGS) and bilateral vocal fold paralysis (BVFP) who also had videoendoscopic examinations. Videoendoscopic examination findings that could help differentiate PGS from BVFP were identified a priori. A weighted scoring index, based on the adjusted odds ratios of significant examination findings on multiple logistic regression, was derived. Associations between the weighted scoring index, patient history, and diagnosis were then evaluated.

Results:

Twenty-six patients with BVFP and 28 patients with PGS were identified. Posterior glottic scar (weight = 2), medial arytenoid erosion with a widened posterior glottis (weight =1), and appropriate vocal fold motion (weight = 1) were significant variables (p ≤ .05, multiple logistic regression) and constituted the weighted scoring index. A weighted scoring index of ≥ 2 and a history of prolonged intubation predicted PGS in 95.2% of cases. A weighted scoring index of ≤ 1 and a history of neck surgery predicted BVFP in 95.0% of cases.

Conclusions:

The weighted scoring index with the patient history provides an objective tool for diagnosing BVFI.

Value of Laryngeal Electromyography in Diagnosis of Vocal Fold Immobility

Objectives:

We sought to determine the value of laryngeal electromyography (LEMG) and evoked LEMG in the diagnosis of vocal fold immobility.

Methods:

We analyzed 110 cases of vocal fold immobility by their clinical manifestations and LEMG characteristics, including spontaneous potential activity, motor unit potential measurement, recruitment pattern analysis, and evoked LEMG signals.

Results:

With LEMG, we identified 87 patients with neuropathic laryngeal injuries. Neurogenic vocal fold immobility showed a wide variety of abnormal activity. Fibrillation potentials and positive sharp waves were found in patients with laryngeal nerve injuries. For laryngeal paralysis, there was no reaction with LEMG and evoked LEMG. For incomplete laryngeal paralysis, decreased evoked LEMG signals were also seen with delayed latency (thyroarytenoid muscle, 2.2 ± 1.0 ms, p < 01; posterior cricoarytenoid muscle, 2.4 ± 1.0 ms, p < .05) and lower amplitude (thyroarytenoid muscle, 0.9 ± 0.7 mV, p < .05; posterior cricoarytenoid muscle, 1.2 ± 1.0 mV, p < .01). Nineteen patients with vocal fold mechanical limitations generally had normal LEMG and evoked LEMG signals. Four patients with neoplastic infiltration of the laryngeal muscles demonstrated abnormal LEMG signals but nearly normal evoked LEMG signals.

Conclusions:

We conclude that LEMG and evoked LEMG behavior plays a crucial role in the diagnosis of vocal fold immobility. The decreased recruitment activities on LEMG and the decreased evoked LEMG signals with longer latency and lower amplitude reflect the severity of neuropathic laryngeal injury.

Photodocumentation of the development of type I posterior glottic stenosis after intubation injury

Bilateral vocal fold immobility may result from bilateral recurrent laryngeal nerve paralysis or physiologic insults to the airway such as glottic scars. The progression of mucosal injury to granulation tissue, and then posterior glottis stenosis, is an accepted theory but has not been photodocumented. This paper presents serial images from common postintubation injury to less common posterior glottic stenosis with interarytenoid synechia.

Pathologies of the larynx and trachea in childhood

Pathologies in the larynx and trachea in the pediatric age can be characterized in 4 main groups: airway stenosis, acute infections, benign neoplasia and foreign body aspiration. In this review main diagnostic strategies and therapeutic options are presented. Laryngomalazia is the most frequent condition of supraglottic stenosis. The term supraglottoplasty summarizes all different techniques used for it's repair using an endoscopic approach. Glottic stenosis is rare in children. Usually a compromise between voice preservation and airway restoration has to be sought. Type of reconstruction and timing are varying considerably in individual cases, endoscopic approaches should be preferred. Subglottic stenosis remains the largest group in paediatric airway pathology, with cicatrial stenosis being predominant. Today, cricotracheal resection is the most successful treatment option, followed by the classical laryngotracheal reconstruction with autologous cartilage. In early infancy subglottic stenosis is particularly demanding. Endoscopic treatment is possible in selected patients, but open reconstruction is superior in more severe cases. Tracheostomy is not a safe airway in early infancy, it's indication should be strict. Foreign body aspiration needs to be managed according to a clear algorhythm. Recurrent respiratory papillomatosis should be treated with emphasis on function preservation. The role of adjuvant medication remains unclear. Infectious diseases can be managed conservatively by a pediatrician in the majority of cases.

Interarytenoid osseous bridge after prolonged endotracheal intubation

Posterior glottic stenosis or interarytenoid fibrous adhesion is uncommon and has sometimes been misdiagnosed as cord paralysis. Laryngoscopy and laryngeal electromyography studies are the two main diagnostic aids. We present the case of a 63-year-old man under endotracheal intubation during 10 days after a cardiac procedure who was evaluated in our department for persistent dysphonia. The laryngoscopy showed a granuloma-like lesion in the posterior glottic space. During the microlaryngoscopy procedure, the osseous consistence of the interarytenoid lesion was observed. Laser surgery excision of the lesion was performed with good results. According to our review of the literature, this corresponds to the second case reported.

Glottic scar bands following intubation

We present two uncommon cases of abnormalities of the pediatric airway, which may present in the first instance to the anesthetist. Glottic scar bands are a result of intubation trauma and are a treatable cause of voice abnormalities and sometimes respiratory distress.

Surgical management of laryngotracheal stenosis in adults

The purpose was to evaluate the outcome following the surgical management of a consecutive series of 26 adult patients with laryngotracheal stenosis of varied etiologies in a tertiary care center. Of the 83 patients who underwent surgery for laryngotracheal stenosis in the Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital of Lausanne, Switzerland, between 1995 and 2003, 26 patients were adults (> or = 16 years) and formed the group that was the focus of this study. The stenosis involved the trachea (20), subglottis (1), subglottis and trachea (2), glottis and subglottis (1) and glottis, subglottis and trachea (2). The etiology of the stenosis was post-intubation injury ( n = 20), infiltration of the trachea by thyroid tumor ( n = 3), seeding from a laryngeal tumor at the site of the tracheostoma ( n = 1), idiopathic progressive subglottic stenosis ( n = 1) and external laryngeal trauma ( n = 1). Of the patients, 20 underwent tracheal resection and end-to-end anastomosis, and 5 patients had partial cricotracheal resection and thyrotracheal anastomosis. The length of resection varied from 1.5 to 6 cm, with a median length of 3.4 cm. Eighteen patients were extubated in the operating room, and six patients were extubated during a period of 12 to 72 h after surgery. Two patients were decannulated at 12 and 18 months, respectively. One patient, who developed anastomotic dehiscence 10 days after surgery, underwent revision surgery with a good outcome. On long-term outcome assessment, 15 patients achieved excellent results, 7 patients had a good result and 4 patients died of causes unrelated to surgery (mean follow-up period of 3.6 years). No patient showed evidence of restenosis. The excellent functional results of cricotracheal/tracheal resection and primary anastomosis in this series confirm the efficacy and reliability of this approach towards the management of laryngotracheal stenosis of varied etiologies. Similar to data in the literature, post-intubation injury was the leading cause of stenosis in our series. A resection length of up to 6 cm with laryngeal release procedures (when necessary) was found to be technically feasible.

Long-term complications of artificial airways

In summary, long-term complications of artificial airways are rare but important sequelae of artificial airways. Many of the potential long-term complications of translaryngeal intubation and tracheotomy are similar and overlapping. Although most patients who undergo these procedures tend to tolerate them without difficulties, significant morbidity and mortality may occur. Identifying the exact cause of the complication may not be possible at times, due to the multiple risk factors involved in the pathogenesis. It is hoped that understanding these potential complications will lead to a more vigilant preventive measures during the institution of long-term artificial airways and a judicious early search for the underlying pathology when a complication is suspected.

Traumatic complications of airway management

Safe and effective airway management techniques have become a hallmark of modern anesthesiology practice, but even such overwhelmingly successful and life-saving practices come with a cost. This cost is morbidity and mortality secondary to the techniques themselves. Closed claims analysis has shown that adverse outcomes secondary to respiratory events constitute the single largest source of injury to patients (75%). Airway management complications are a significant subset of these outcomes. Difficult intubation was shown to be a factor in only slightly more that one third (38%) of these claims. Six percent of closed claims were for airway trauma. These data indicate that injury frequently occurs without initial difficulty in management of the airway, may occur throughout the perioperative period, and can be unexpected when it occurs. Thorough knowledge of the mechanisms of airway injury associated with different airway management techniques may allow for better patient outcomes. This chapter reviews complications of airway management involving the placement of endotracheal tubes. In addition, because laryngeal mask airways (LMAs) have gained increasing prominence in airway management use in the past 10 years, complications relating to their use will also be reviewed.

Management of bilateral arytenoid cartilage fixation versus recurrent laryngeal nerve paralysis

Bilateral arytenoid cartilage fixation (ACF) closely resembles vocal cord immobility due to recurrent laryngeal nerve paralysis (RLNP). This study sought to determine the etiologic differences between these two entities and to derive conclusions about treatment. The charts of 218 consecutive adult patients with immobility of both vocal cords requiring surgery for airway restoration were reviewed. The results of laryngeal electromyography and laryngotracheoscopy were used to distinguish ACF from RLNP. In 186 patients (85.3%), RLNP was identified. Of these, 154 paralyses (82.8%) were caused by surgical interventions, 5 (2.7%) were caused by previous intubation, 16 (8.6%) were caused by various malignancies, and 7 (3.8%) were neurogenic. In 4 patients (2.2%), the cause remained unclear. We identified ACF in 32 patients. The etiologic factors included previous long-term intubation in 22 patients (68.8%), short-term intubation in 3 patients (9.4%), Wegener's granulomatosis in 3 patients (9.4%), rheumatoid arthritis in 2 patients (6.3%), previous laryngeal surgery in 1 patient (3.1%), and caustic ingestion in 1 patient (3.1%). Additional second-site airway stenosis was found in 10 of the RLNP patients (5.4%) and in 15 of the ACF patients (46.9%). All RLNP patients had endoscopic surgery without temporary tracheotomy. Eighteen ACF patients required open surgery, and 4 were managed endoscopically but required temporary tracheotomy. The etiologic factors were significantly different for the two entities under study. Additional sites of stenosis were more frequent in ACF patients. Stenosis due to RLNP could be managed endoscopically without preliminary tracheotomy, while ACF frequently required open surgery and temporary tracheotomy.