Autologous collagen vocal fold injection: A preliminary clinical study

This preliminary study reports the first use of injectable autologous collagen for vocal fold augmentation. In previous studies, the authors showed cross-linked bovine collagen to be effective in more than 150 patients with glottic incompetence, particularly those with focal defects or scarred or atrophic vocal folds. However, concerns about possible adverse immunologic responses to the bovine material have limited its use. The authors studied eight patients with difficult vocal fold pathology, including sulcus vocalis, atrophy, and scarring secondary to trauma and cordectomy. Skin was harvested under local anesthesia, processed into a naturally cross-linked injectable form (Autologen®), and injected using indirect laryngoscopy. Voice production was evaluated prior to the injection and at intervals after the injection, using subjective, perceptual, aerodynamic, acoustic, and videostroboscopic assessments. The results indicate that autologous collagen is comparable to injectable bovine collagen in the management of several difficult glottic insufficiency problems and that the likelihood of a hypersensitivity response is negligible. Unlike bovine collagen preparations, Autologen does not require breakdown of the natural collagen molecule, so it is anticipated that this material will be better tolerated and more stable over time.     

New-generation pulsed carbon dioxide laser: comparative effects on vocal fold wound healing

We investigated wound healing of vocal fold mucosal excisions using a canine model, comparing cold steel, the continuous wave (CW) carbon dioxide (CO2) laser, and a new, microsecond-pulsed CO2 laser. The thermal injury to the surrounding normal tissues produced by the laser increases the risk for scar formation and poor functional voice outcome. This injury may be reduced with a pulsed CO2 laser. Acute, 2-week, and 6-week studies of 15 dogs were made with blinded observers and nonparametric statistical analyses. Histologic comparison showed less thermal injury and scar formation in the vocal folds treated with the pulsed CO2 laser than with the CW CO2 laser. Functional outcomes as studied with laryngeal videostroboscopy revealed better vibratory characteristics with the pulsed CO2 laser as compared with the CW CO2 laser. No differences were seen on these measures between the pulsed laser and cold techniques. Pulsed CO2 lasers may offer the ease of laser laryngology and the superior wound healing of cold steel.     

Clinical experience with collagen injection of the vocal fold: a study of 155 patients

OBJECTIVE: This study evaluated the results of laryngeal collagen injection. STUDY DESIGN: Retrospective study of patients who had undergone laryngeal collagen injection. MATERIALS AND METHODS: A retrospective review of 275 patients treated with collagen injection and a review of the relevant literature on the results of treatment were presented. Follow-up studies were performed for at least 3 months on 155 patients. The patients' voice quality was assessed by perceptual voice analysis using the GRBAS scale, and their vocal function was assessed by acoustic and aerodynamic measures (maximal phonation time and mean flow rate). Assessments were performed before and after collagen injection. RESULTS: Mean objective measures and clinician's perceptual ratings demonstrated measurable improvement in vocal function and voice quality after collagen injection. There were no major complications and no hypersensitivity reactions. CONCLUSION: As an outpatient office procedure, collagen injection offers a simple, efficient and effective treatment for dysphonia. Various aspects of the procedure for anesthesia, injection techniques, and patient selection are discussed.     

Treatment of vocal fold immobility by injectable homologous collagen: short-term results

Various implant materials have been used to treat glottic insufficiency by means of intracordal injection. So far, autologous fat is the most commonly used. Homologous collagen is a new injectable acellular graft material. This collagen, made of 200- particles, is delivered as a freeze-dried powder in a 1-cc-unit syringe and is rehydrated with standard saline solution prior to injection. A prospective study was conducted on 23 patients with unilateral vocal fold paralysis. All injections were performed under general anesthesia using the collagen injection system and a 25-gauge needle. A mean quantity of 1.05 ml (SD: 0.41) of collagen was injected as much as possible in the deep part of the lamina propria. Voicing was resumed after 2 days. The mean follow-up was of 8 months (range: 2–18). Functional results were measured according to the ELS protocol. G(rade), R(oughness) and B(reathiness) according to Hirano were reported on a four-point grading scale showing an improvement from 2.13 to 1.13 for G (P<0.001), from 1.50 to 0.82 for R (P<0.002) and from 1.73 to 1.05 for B (P<0.001). The parameters selected for videolaryngostroboscopy, G(lottal) (Clo)sure, (R)egularity, (M)ucosal (W)ave and (Sym)metry, were measured on a visual analog scale. They showed an improvement from 23 to 19 for Clo (P=0.087), from 15 to 6 for R (P=0.001), from 15 to 11 for MW (P=0.039) and from 17 to 8 for Sym (P=0.001). For the aerodynamic parameters, the maximum phonation time (MPT) and the phonation quotient (PQ) showed an improvement from 5.8 to 8.9 s (P=0.002) and from 704.5 to 449.7 ml/s (P=0.004), respectively. The acoustic parameters were improved from 5.3 to 3.6 (P=0.045) for the jitter (%), they didnt change for the shimmer [(%): 2.4], and they were improved non-significantly from 187.9 to 218.7 Hg for the frequency range. The lowest level intensity was non-significantly increased from 49.6 to 51.3 dB. Regarding the subjective evaluation, the Voice Handicap Index (VHI) was improved from 65 to 37. To date, no homologous collagen-related morbidity has been observed. Injectable homologous collagen appears to be safe and suitable for injection laryngoplasty. Long-term results are pending.     

Pediatric bilateral vocal fold immobility: the role of carbon dioxide laser posterior transverse partial cordectomy

Vocal fold paralysis in children has been estimated to be the second most common congenital abnormality of the pediatric airway. Most commonly, children present with the vocal folds in the midline or adducted position. Pediatric patients usually have a good voice or cry and a poor airway. In these cases, the surgical goal will be improving the airway, usually by lateralizing a vocal fold, while maintaining a normal voice and intact swallowing. The focus of this article is a modification of a technique for use in adults that was introduced by Dennis and Kashima in 1989. The procedure is intended to separate the vocal ligament and vocalis muscle from the arytenoid cartilage with removal of significant tissue mass with the CO2 laser. The demographics and results of 5 pediatric patients who underwent this procedure are discussed. The preoperative goals of airway enlargement, voice preservation, and normal deglutition were achieved in all 5 patients.     

Subtotal carbon dioxide laser arytenoidectomy for the treatment of bilateral vocal fold immobility: long-term results

Sixty-nine patients underwent subtotal carbon dioxide laser arytenoidectomy for treatment of bilateral vocal fold immobility between 1985 and 2000. The population included 69 patients whose mean age was 56 years (SD, 16 years; range, 11 to 82 years). The mean follow-up was 50 months (SD, 44 months; range, 1 to 181 months). The overall postoperative peak expiratory/peak inspiratory flow ratio (normal value, 1) significantly improved (closer to 1; p = .0036). Voice analyses were also undertaken for 27 patients, almost exclusively after operation, given the context of initial emergency. The maximum phonation time averaged 6.57 seconds (median, 6 seconds). The phonation quotient remained high, with a mean of 503 (median, 440), and the mean conversational voice intensity remained around 59 dB. The median frequency analysis type was 3. The advantage of subtotal arytenoidectomy lies in the fact that it maintains a certain degree of rigidity along the posterior limit of the arytenoid frame, preventing inward collapse of the mucosa and thus lowering the risk of aspiration.     

Pediatric vocal fold paralysis: a long-term retrospective study

OBJECTIVE: To review our experience of pediatric vocal fold paralysis (VFP), with particular emphasis on etiological factors, associated airway pathologic conditions, and treatment and prognostic outcomes. DESIGN: Retrospective case review of a cohort of patients presenting with VFP. SETTING: Tertiary referral center. PATIENTS: A consecutive sample of 102 patients presenting with VFP to Great Ormond Street Hospital for Children, London, England, over a 14-year period from 1980 to 1994. RESULTS: There was an almost equal distribution of unilateral (52% [n = 53]) and bilateral (48% [n = 49]) VFP. Iatrogenic causes (43% [n = 44]) formed the largest group, followed by idiopathic VFP (35% [n = 36]), neurological causes (16% [n = 16]), and finally birth trauma (5% [n = 5]). Associated upper airway pathologic conditions were noted in 66% (n = 23) of patients who underwent tracheotomy. Tracheotomy was necessary in only 57% (n = 28) of children with bilateral VFP. Prognosis was variable depending upon the cause, with neurological VFP having the highest rate of recovery (71% [5/7]) and iatrogenic VFP the lowest rate (46% [12/26]). CONCLUSION: Recovery after an interval of up to 11 years was seen in idiopathic bilateral VFP; this has significant implications when considering lateralization procedures in these patients.     

Correcting vocal fold immobility by autologous collagen injection for voice rehabilitation. A short-term study.

We report on a short-term clinical study of injectable autologous collagen (Vocalogen) used to correct dysphonias arising from vocal fold immobility. The collagen is extracted from skin taken from the lower abdominal quadrant area or from just above the bikini line. About 30 cm2 of skin are required to provide 2 mL of injectable collagen. The histologic examination of the preparation before injection disclosed the presence of elastin fibers and some clusters of epithelial cells, beside the collagen fibers. The collagen is naturally reticulated, and the molecule is preserved in its entirety. The technique is exactly the same as that reported for bovine collagen: injection into Reinke's space, under general anesthesia, monitored by direct microlaryngoscopy. The amount injected is also similar: 1.5 mL for correction of glottic insufficiency in which the immobile vocal fold is in the intermediate position. Eight patients were injected, and the average follow-up was 4.5 months. Voice assessments made before and after the treatment included stroboscopy, subjective and perceptual judgments, and aerodynamic and acoustic measurements. The functional results were similar to those obtained with bovine collagen. No complications arose. The probability of any hypersensitivity reaction, always a possibility to be feared with bovine collagen, is negligible with the autologous collagen. Long-term results are as yet unknown, but from the fact that the collagen molecular structure is intact and there is little risk of foreign body response, it would be expected that autologous preparations would be more stable than bovine collagen; this appears to be the case in cosmetic applications. Autologous collagen could be employed for the same indications as bovine collagen, provided that a delay of 45 days (the time required to prepare the injectable collagen) is acceptable. The amount of collagen required is also a limiting factor, since the patient's own skin is the starting donor material.     

The use of the pulse dye laser in the treatment of vocal fold scar: a preliminary study

Objectives/Hypothesis: Dysphonia due to vocal fold scarring is a challenging problem to the laryngologist. Vocal fold scarring after radiation, phonosurgery, and laser cordectomy causes moderate to severe dysphonia. Surgical attempts at scar removal and voice restoration have limited success. Pulsed dye laser (PDL) treatment has been shown to be effective in softening scarred skin by serial office treatments. The objective of this preliminary study was to evaluate the use of the PDL in the management of patients with established vocal fold scar. Study Design: This is an Institutional Review Board‐approved prospective study involving 11 patients. The causes of scarring were phonosurgery (n = 7), radiation (n = 2), and partial laryngectomy (n = 2). The subjects were evaluated pre‐ and postprocedure using the voice handicap index (VHI), laryngeal stroboscopy rating, voice recordings with acoustic and aerodynamic analysis, and self‐evaluation. Methods: The PDL was applied with the fiberoptic delivery system by three treatments at 1‐month intervals in the office setting. Each treatment endpoint was blanching of the treatment site. Results: There were three women and eight men in our study group. Ten of 11 patients subjectively improved by self‐rating. No patients were worse. VHI improved from 48.44 pretreatment to 35.55 at 6 months posttreatment (P < .05). The jitter at 6 months improved from 2.230% to 1.654% (P = NS) and shimmer improved from 3.679% to 3.196% (P = NS). The noise to harmonic ration improved from 0.1428 to 0.1316 (P = NS). The mean phonotory flow went from 0.177 to 0.254 L/S (P < .05).Three raters blinded to treatment sequence rated the posttreatment stroboscopy findings as better than pretreatment in a forced choice comparison, kappa score 0.903. Conclusion: PDL is a safe and potentially promising treatment for established vocal fold scar. Subjectively, no patients were worse and 10 of 11 patients reported improved voice. There was improvement in the VHI, acoustic measures of shimmer and jitter, and stroboscopy findings. Further study using this approach in a larger cohort seems to be warranted.     

声带瘢痕的概念与对策

声带瘢痕是喉科医师面临的最大挑战之一，要改善或恢复由声带瘢痕引起的发声障碍，目前尚无明确有效的治疗方法。各种原因的喉腔损伤都会形成声带瘢痕，包括外伤、嗓音手术(phonosurgery)、放疗、炎症和气管插管的损伤。明确声带瘢痕与发声障碍的关系，需要系统的病史回顾、临床嗓音评估、多种方法的试验性治疗。声带瘢痕导致发声障碍的过程非常复杂，现就声带瘢痕研究近况做一介绍。     

Treatment of vocal fold scarring: rheological and histological measures of homologous collagen matrix

The current treatment options for dysphonia secondary to vocal fold scarring are limited. Few studies address changes in the lamina propria, which is critical to vocal fold biomechanical properties and voice production. Using rheological and histological measures of homologous collagen matrix (HCM)-injected vocal folds, we assessed HCM's potential for providing bulk and restoring biomechanical performance. Twenty rabbits underwent bilateral vocal fold scarring. After 10 weeks of scar maturation, the rabbits had unilateral injections of HCM or saline solution. Ten weeks after the injections, histological studies revealed well-defined collagen globules distributed throughout the lamina propria and underlying muscular tissue. Significantly more procollagen was observed in the HCM-treated group. No significant differences in elastic shear modulus or dynamic viscosity were found between the treatment groups. This study demonstrates that HCM is an inert, relatively stable injectate that may serve well for medialization but does not appear to improve the dynamic properties of the lamina propria.     

Phonosurgical vocal fold injection: procedures and materials

Significant advances have recently occurred in the area of vocal fold injection. Phonosurgical vocal fold injection is now a precise set of techniques used to improve voice quality through vocal fold injection. Lipoinjection and collagen injection are discussed in detail. The different vocal fold injection techniques and materials are discussed in this article.     

Carbon dioxide laser microsurgery of benign vocal fold lesions: indications, techniques, and results in 251 patients

Two hundred fifty-one carbon dioxide laser-assisted cases of microphonosurgery are reported. Our series includes 167 women (66.5%) and 84 men (33.5%), with a mean age of 41 (+/-11) years. Single lesions represent 67.8% (n = 170) of the cases, with 20% (n = 50) being nodules, 18% (n = 44) Reinke's edema, 9% (n = 23) polyps, 8% (n = 19) sulci and related lesions, 6% (n = 16) mucosal cysts, 4% (n = 10) scars, 2% (n = 4) granulomas, and 2% (n = 4) vascular corditis. The cases with 2 or 3 lesions represented 32% (n = 81). Carbon dioxide laser-assisted microphonosurgery is efficient, provided the working parameters are strictly adhered to: micromanipulator micropoint providing a 250-microm laser beam for a 400-mm working distance; 0.1-second single pulses; and maximum power of 3 W with the superpulse wave. Glutaraldehyde-cross-linked collagen remains our filling material of choice in cases of vocal fold atrophy. Fibrin glue is useful for covering the resection area and for setting the microflaps. Microphonosurgery cannot be dissociated from speech therapy, the planning and duration of which, in relation to the procedure, depend on the nature of the initial lesion. Twenty to 30 sessions are usually adequate, but 6 months may be necessary in the case of sulcus vergetures. Our operating technique is derived from the microphonosurgery procedures with cold instruments. In addition to the classic advantage with regard to hemostasis, the carbon dioxide laser micropoint seems to make the dissection of microflaps easier.     

Qualitative and morphometric evaluation of vocal cord lesions produced by the carbon dioxide laser

The canine larynx was studied to obtain qualitative and quantitative data accurately defining the destructive effects of the carbon dioxide laser on epithelial tissue by administering doses of varied energy to the dorsal surface of the vocal cords. Resultant lesions subsequently were analyzed by light, transmission, and scanning microscopy. Three major morphologic patterns of vocal cord lesions were observed: 1. cup shape, 2. doughnut shape and, 3. complex star shape. The patterns produced in the laryngeal tissue reflect the operative mode (energy distribution within the focused spot of energy) of the laser at the time of surgery. The mode resulting in the doughnut shaped pattern (energy distribution around the periphery of the spot) produced deepest lesions, with minimal thermal conduction laterally, whereas the mode resulting in the cup-shaped pattern (energy distribution uniform throughout the spot) produced at comparable doses shallower lesions with larger diameter. Too few star-shaped patterns were observed to permit meaningful morphometric analysis.     

Vocal fold lateralization using carbon dioxide laser and fibrin glue.

Lateralization of one or both vocal folds is a generally accepted surgical principle for the relief of the airway obstruction caused by bilateral vocal fold paralysis. A modified, entirely endoscopic method of lateralization has been developed, employing a carbon dioxide laser to reduce the bulk of the fold, and fibrin glue to maintain the lateral position. The results of 18 operations on 15 patients, including six who had unsatisfactory results after previous surgery, were analyzed and compared retrospectively with the results from 22 patients operated on before the introduction of the method. The patient's ability to perform everyday activities improved in 12 cases, which paralleled the results of the previous, more cumbersome methods. The incidence of re-operation was comparable, given the shorter follow-up after the more recent method.