Autologous fat implantation for vocal fold scar: A preliminary report

New insights into the anatomy and physiology of phonation, along with technological advances in voice assessment and quantification, have led to dramatic improvements in medical voice care. Techniques to prevent vocal fold scar have been among the most important, especially scarring and hoarseness associated with voice surgery. Nevertheless, dysphonia due to vocal fold scar is still encountered all too frequently. Although it is not generally possible to restore such injured voices to normal, patients with scar-induced dysphonia can usually be helped. Voice improvement is optimized through a team approach. Treatment may include sophisticated voice therapy and vocal fold surgery. Although experience with collagen injection has been encouraging in selected cases (particularly in those involving limited areas of vocal fold scar), there is no consistently successful surgical technique. Attempts to treat massive vocal fold scar, such as may be seen following vocal fold stripping, have been particularly unsuccessful. This paper reports preliminary experience with the implantation of autologous fat into the vibratory margin of the vocal fold of patients with severe, extensive scarring. Using this technique, it appears possible to recreate a mucosal wave and improve voice quality. Additional research is needed.     

Fibronectin: An Interesting Vocal Fold Protein

A great deal of information is accruing regarding the function of the extracellular matrix. Once thought to be simply a structural entity to surround cells, it is now known to do much more. Fibronectin in particular has received specific attention. Fibronectin is a ubiquitous glycoprotein found most abundantly in the extracellular matrix of regenerating, healing, and embryonic tissue. Vast evidence supports the fact that fibronectin participates in many diverse functions throughout the body that are relevant to vocal fold biology. This article introduces the structure of fibronectin and its isoforms and provides an introduction to some of the many functions it plays. It also reviews the evidence about fibronectin's place in vocal folds and vocal fold pathology. It discusses fibronectin's presence in vocal nodules, vocal polyps, vocal scarring, and Reinke's edema, and reviews the data on its role in mucosal wave impairment. Lastly, it discusses preliminary microarray data that show gene expression for fibronectin to be upregulated in true vocal folds when compared to false vocal folds.     

Interstitial protein alterations in rabbit vocal fold with scar

Fibrous and interstitial proteins compose the extracellular matrix of the vocal fold lamina propria and account for its biomechanic properties. Vocal fold scarring is characterized by altered biomechanical properties, which create dysphonia. Although alterations of the fibrous proteins have been confirmed in the rabbit vocal fold scar, interstitial proteins, which are known to be important in wound repair, have not been investigated to date. Using a rabbit model, interstitial proteins decorin, fibromodulin, and fibronectin were examined immunohistologically, two months postinduction of vocal fold scar by means of forcep biopsy. Significantly decreased decorin and fibromodulin with significantly increased fibronectin characterized scarred vocal fold tissue. The implications of altered interstitial proteins levels and their affect on the fibrous proteins will be discussed in relation to increased vocal fold stiffness and viscosity, which characterizes vocal fold scar.     

Collagen injection in the scarred vocal fold

Scar tissue in the vocal fold can impair vibration and voice quality. The association of scarring and glottic insufficiency prompted our use of injectable bovine collagen in a variety of pathologic conditions exhibiting vocal fold scarring. Incremental augmentation and improved glottic function in several treated patients seemed to be facilitated by softening of scar tissue. Although the use of bioimplants in the larynx is associated with immunologic risks, the proclivity to soften scar tissue is one potential benefit of such materials. The biological activity of injectable collagen seems to alter local collagen metabolism by promoting ingrowth of host fibroblasts that are active in collagen degradation and synthesis. Further research to study the mechanisms whereby injectable collagen promotes remodeling of connective tissue might have significant therapeutic implications in the management of laryngeal scarring.     

Reflux and vocal disorders in singers with bulimia

Dysphonia associated with bulimia has been described in the literature associated with vocal fold edema and polypoid changes. Laryngopharyngeal reflux (LPR) has been documented to cause reflux vocal fold pathology including edema and polypoid changes. We studied eight singers with bulimia and documented vocal fold pathology, including edema, posterior commissure hypertrophy, ventricular obliteration, and telangiectasia. Reflux was demonstrated in all eight. The results of this study showed that LPR may be a contributing factor to vocal disorders in singers with bulimia.     

Sarcoidosis Presenting as Bilateral Vocal Fold Paralysis

Sarcoidosis with cranial polyneuritis and mediastinal granulomatous compression as a cause of unilateral left vocal fold paralysis has been reported infrequently. No case of sarcoidosis causing bilateral vocal fold paralysis in the abducted position has been reported in the Otolaryngology/Voice literature. Vocal fold function can be impacted in sarcoidosis by direct laryngeal involvement or by neural pathways. In the patient described in this case, sarcoid cranial polyneuritis coupled with bilateral paratracheal and mediastinal adenopathy resulted in bilateral vocal fold paralysis. This patient had a dramatic response to treatment with steroids. Sarcoidosis should be included in the differential diagnosis of unilateral or bilateral vocal fold paralysis.     

The treatment of vocal fold paralysis with injectable collagen: Clinical concerns

Over the past several years, the treatment of vocal cord paralysis has been substantially improved by the availability of injectable Teflon. This substance, suspended in glycerin, has provided consistent results in laryngeal rehabilitation due to its tissue tolerance and lack of resorption. Recently, moified bovine collagen has been proposed as an additional substance for use in vocal cord injections to treat vocal fold paralysis. Collagen is currently being used for augmentation of dermatologic scarring, especially on the face. It has undergone clinical trials and has now been approved for clinical use in this setting. Bovine collagen has proven very useful in scar modification. The injections are generally well tolerated and adverse responses do not often occur. Most of the adverse local reactions can be avoided by using a skin test on the forearm 1 month prior to treatment and excluding those patients with positive responses.     

Dysphonia and bulimia: Vomiting laryngeal injury

Voice problems associated with vomiting laryngeal injury in bulimic patients have not been previously described in the literature. Injuries found include subepithelial vocal fold hemorrhages that probably go on to produce mucosal wave tethering. More severe scarring may also result, but superficial telangiectasia of the glottic mucosa seems to be a more common feature. Three patients from a voice clinic population are described, and a further 10 patients from an eating disorders clinic who had not presented with voice complaints were studied with questionnaires, history, video laryngostroboscopy, and voice recordings.     

Paradoxical vocal fold movement: A case report

We present a case of one patient with respiratory stridor that was resolved by speech therapy. Paradoxical vocal fold movements were observed by flexible fiberoptic videolaryngoscopy in this patient during episodes of wheezing and dyspnea. Otherwise, normal vocal fold movement was observed in normal conditions of breathing (out of the crisis) and during phonation. Many different terms have been used to describe this entity in the literature, and it is crucial that clinicians recognize the subtle signs of functional stridor. Paradoxical vocal fold motion has to be considered as an important cause of respiratory disease. Its recognition and treatment are discussed in this report.     

Characterization of chronic vocal fold scarring in a rabbit model

The purpose of the current study was to assess the histologic and rheologic properties of the scarred vocal fold lamina propria during a chronic phase of wound repair in a rabbit model. Eighteen rabbit larynges were scarred using a procedure that involved stripping the vocal fold lamina propria down to the thyroarytenoid muscle, using 3-mm microforceps. The approximate dimension of injury to the vocal fold was 3 x 1.5 x 0.5 mm [length x width x depth]. At 6 months postoperatively, histologic analysis of the scarred and control lamina propria in eight of these rabbits was completed for collagen, procollagen, elastin, and hyaluronic acid. Compared with control samples, scarred tissue samples revealed fragmented and disorganized elastin fibers. Additionally, collagen was significantly increased, organized, and formed thick bundles in the scarred vocal fold lamina propria. Measurements of the viscoelastic shear properties of the scarred and control lamina propria in the remaining 10 rabbits revealed increased elastic shear modulus (G') in 8 of 10 scarred samples and increased dynamic viscosity (eta') in 9 of 10 scarred samples. Although rheologic differences were not statistically significant, they revealed that on average, scarred samples were stiffer and more viscous than the normal controls. Histologic data are interpreted as indicating that by 6 months postinjury, the scarred rabbit vocal fold has reached a mature phase of wound repair, characterized by an increased, organized, and thick bundle collagen matrix. Rheologic data are interpreted as providing support for the potential role of increased, thick bundle collagen, and a disorganized elastin network on shear stiffness and dynamic viscosity in the chronic vocal fold scar. Based on these results, a 6-month postoperative time frame is proposed for future studies of chronic vocal fold scarring using the rabbit animal model.     

Histologic and Rheologic Characterization of Vocal Fold Scarring

Scarring of the vocal fold causes considerable dysphonia and presents significant treatment challenges. A rabbit model was developed to investigate the histologic ultrastructure and rheologic properties of the scarred vocal fold lamina propria. Eleven rabbit larynges were scarred by means of forcep biopsy. Sixty days postoperatively, the rabbits were sacrificed and their vocal folds were harvested. Histological analysis of the scarred and normal lamina propria was completed for collagen, procollagen, elastin, and hyaluronic acid. Linear viscoelastic shear properties of the tissues were also measured, including elastic shear modulus and dynamic viscosity. Compared to normal vocal fold lamina propria, scarred tissues demonstrated significantly less collagen, an increase in procollagen, and a decrease in elastin. Rheologically, both elastic shear modulus and dynamic viscosity were significantly higher for the scarred tissues. Increased stiffness and viscosity do not appear to result from an increase in collagen, but rather appear to be related to the presence of new, disorganized collagen scaffolding. Results are interpreted in terms of the possible role of interstitial proteins in the etiology of increased stiffness and viscosity, which requires further investigation. This animal model should allow for systematic future investigations of vocal fold scarring and its treatment.     

Dependence of phonation threshold pressure on vocal tract acoustics and vocal fold tissue mechanics

Analytical and computer simulation studies have shown that the acoustic impedance of the vocal tract as well as the viscoelastic properties of vocal fold tissues are critical for determining the dynamics and the energy transfer mechanism of vocal fold oscillation. In the present study, a linear, small-amplitude oscillation theory was revised by taking into account the propagation of a mucosal wave and the inertive reactance (inertance) of the supraglottal vocal tract as the major energy transfer mechanisms for flow-induced self-oscillation of the vocal fold. Specifically, analytical results predicted that phonation threshold pressure (Pth) increases with the viscous shear properties of the vocal fold, but decreases with vocal tract inertance. This theory was empirically tested using a physical model of the larynx, where biological materials (fat, hyaluronic acid, and fibronectin) were implanted into the vocal fold cover to investigate the effect of vocal fold tissue viscoelasticity on Pth. A uniform-tube supraglottal vocal tract was also introduced to examine the effect of vocal tract inertance on Pth. Results showed that Pth decreased with the inertive impedance of the vocal tract and increased with the viscous shear modulus (G") or dynamic viscosity (eta') of the vocal fold cover, consistent with theoretical predictions. These findings supported the potential biomechanical benefits of hyaluronic acid as a surgical bioimplant for repairing voice disorders involving the superficial layer of the lamina propria, such as scarring, sulcus vocalis, atrophy, and Reinke's edema.     

Preliminary Results of a New Temporary Vocal Fold Injection Material

Temporary vocal fold injection is a valuable procedure for vocal fold paralysis or paresis of uncertain permanency and as a trial augmentation to decide the value of vocal fold augmentation. A new material made from glycerin, carboxymethylcellulose, and water has recently been developed for temporary vocal fold augmentation. Eleven patients underwent vocal fold injection for the treatment of glottal incompetence with this material. The duration of effectiveness of this injection material was 2 to 3 months depending on the injection amount. This new material satisfies several requirements for an ideal temporary vocal fold injection material in terms of injectability, convenience, duration of effectiveness, and safety. The authors conclude that this new material is a good option for temporary vocal fold augmentation.     

Spatial arrangement of the structural elements ofvocal fold layers: An adjustment to the vibration process

It is well established that the multilayered structure of the vocal fold is highly adjusted to the requirements of the vibration process during phonation. There is also some partial data indicating that the spatial arrangement of each vocal fold layer corresponds to the functional requirements, and thus facilitate the phonation process. Nevertheless, all reports on the spatial arrangement of the vocal fold structures deal only with an individual element of the vocal fold histologic structure. The present study encompasses the spatial histologic analysis of all major elements of the vocal fold layers. It was demonstrated that the vocal fold epithelial cells, the connective and muscle fibers, and even the blood vessels run parallel to the vocal fold free edge, which indicates a high adjustment to the phonation requirements and the vibration process.     

Vocal fold paralysis secondary to cardiac countershock (cardioversion)

Application of electrical energy to the heart is effective in treating many dysrhythmias. There are, however, also disadvantages associated with cardioversion. Employment of external electrical current has been shown to induce epicardial and myocardial damage at the site of electrode application. We present the only case in the English literature of vocal fold paralysis in which the single identified associated event was cardioversion. In this case of temporary vocal fold paralysis, there was no invasive procedure to directly damage the nerve. Echocardiography of the patient revealed a large left atrium, placing the recurrent laryngeal nerve in an abnormal anatomic position where it was vulnerable to the electric current.     

Botulinum toxin injection in the treatment of vocal fold paralysis associated with multiple sclerosis: A case report

Botulinum toxin has been demonstrated clinically to be an effective treatment for a variety of laryngeal problems, most notably spasmodic dysphonia. As in other movement disorders, the theory behind the injection of this substance in the larynx has been a weakening of the vocal fold musculature to relieve uncoordinated and spasmodic movement of the vocal folds, presumably rebalancing the forces within the intralaryngeal musculature. Recently, this concept was applied to help reposition the arytenoid cartilage in acute and longstanding anteromedial cricoarytenoid dislocations. This same concept may apply to the paralyzed vocal fold. In support of this idea, a number of investigators have shown that immobile, clinically paralyzed vocal folds may still have partial voluntary motor unit activity. This voluntary activation may not produce clinically evident movement but may be sufficient to produce tone within the fold. If the voluntary motor units in the abductor musculature of the paralyzed fold are weakened with botulinum toxin, the continued pull of the functioning adductor musculature may be sufficient to medialize the paralyzed fold. This idea has been supported by animal experiments, which have shown that botulinum toxin may affect the ability of the fold to rebalance itself. With this evidence in mind, a patient with fold immobility secondary to multiple sclerosis was treated in an attempt at laryngeal rebalancing, using botulinum toxin to medialize the fold. However, instead of simply having the fold return fixed to the midline, the patient regained normal laryngeal mobility and voice. While it is unclear whether the botulinum toxin alone was responsible, the coincidence of this occurrence certainly requires reporting. This paper is a report of the first successful treatment of vocal fold paralysis using botulinum toxin to treat vocal fold fixation in a patient with multiple sclerosis.     

Complications of collagen injection of the vocal fold: report of several unusual cases and review of the literature

Injection laryngoplasty is one of the most frequently performed procedures in patients with voice complaints. Various biomaterials have been used to medialize vocal folds or to treat symptoms of vocal fold scar. The ideal biomaterial would be easily injected through a fine-gauge needle, well tolerated, and long lasting. Injectable collagen preparations fulfill at least two of these criteria, and collagen has been used widely for vocal fold injections. MATERIALS AND METHODS: We present a retrospective review of two unusual complications of collagen injection and a review of the relevant literature on the complications of medical use of collagen compounds. RESULTS: Two patients in whom collagen was injected formed firm submucosal deposits that interrupted the normal mucosal wave and produced significant dysphonia. Surgical removal of these deposits restored the mucosal wave and improved voice quality. Management of this unusual complication of human collagen injection in the vocal fold has not been reported previously. Other complications of collagen injection include hypersensitivity reactions to bovine collagen, local abscess formation at injection sites, and possibly induction of collagen vascular disease in some patients. CONCLUSIONS: Although collagen injections of the vocal fold rarely result in complications, physicians using collagen must be familiar with the types of complications that can occur. Proper diagnosis and prompt management of complications can result in good outcomes.     

Glottal opening in patients with vocal fold tissue changes

Synchronized videostroboscopy and electroglottography were applied to the measurement of anterior-to-posterior open glottal length in four groups of patients; two with no clinically significant voice disorder, one with vocal fold polyps, and one with vocal fold nodules. The data showed that the groups did not differ significantly when open glottal length was measured at the time of minimum glottal opening. The pathological groups had significantly lower open glottal length measurements, however, when measurements were obtained at the time that vocal fold contact was initiated during the glottal cycle. The findings are preliminary evidence that vocal fold neoplasms may not have the effect of reducing glottal closure, as previously suggested in the literature. The data also highlight the importance of examining differential effects of vocal fold neoplasms at various points throughout the glottal cycle.     

Outpatient transoral laser vaporization of anterior glottic webs and keel placement: Risks of airway compromise

Management of acquired anterior glottic webs involves resection of the web with reconstitution of a linear vocal fold edge and anterior commissure. Traditional procedures such as transcervical midline thyrotomy (with tracheostomy) and keel placement have been used for patients with extensive scar formation and airway compromise. However, in selected patients with more limited scarring and minimal-to-no airway compromise, a transoral endoscopic approach may be a viable option. In three patients, transoral laser vaporization followed by transoral keel placement and outpatient removal resulted in a vocal quality that perceptually improved without any evidence of respiratory compromise postoperatively.