Laryngeal collagen injection as an adjunct to medialization laryngoplasty

An Update on the Clinical Efficacy and Safety of Collagen Injectables for Aesthetic and Regenerative Medicine Applications

Soft tissues diseases significantly affect patients quality of life and usually require targeted, costly and sometimes constant interventions. With the average lifetime increase, a proportional increase of age-related soft tissues diseases has been witnessed. Due to this, the last two decades have seen a tremendous demand for minimally invasive one-step resolutive procedures. Intensive scientific and industrial research has led to the recognition of injectable formulations as a new advantageous approach in the management of complex diseases that are challenging to treat with conventional strategies. Among them, collagen-based products are revealed to be one of the most promising among bioactive biomaterials-based formulations. Collagen is the most abundant structural protein of vertebrate connective tissues and, because of its structural and non-structural role, is one of the most widely used multifunctional biomaterials in the health-related sectors, including medical care and cosmetics. Indeed, collagen-based formulations are historically considered as the "gold standard" and from 1981 have been paving the way for the development of a new generation of fillers. A huge number of collagen-based injectable products have been approved worldwide for clinical use and have routinely been introduced in many clinical settings for both aesthetic and regenerative surgery. In this context, this review article aims to be an update on the clinical outcomes of approved collagen-based injectables for both aesthetic and regenerative medicine of the last 20 years with an in-depth focus on their safety and effectiveness for the treatment of diseases of the integumental, gastrointestinal, musculoskeletal, and urogenital apparatus.

Voice outcome after vocal fold injection augmentation with carboxymethyl cellulose versus calcium hydroxyapatite

BACKGROUND

Vocal fold injection augmentation is a recognised treatment modality for glottic insufficiency. Causes of glottal closure insufficiency include vocal fold paralysis, paresis, atrophy, sulcus vocalis, scarring and vocal fold deficiency after laryngeal surgery. A variety of materials exist for injection augmentation. This study aimed to compare voice improvement after injection augmentation between two injectable materials: carboxymethyl cellulose and calcium hydroxyapatite.

METHOD

This retrospective study included 66 consecutive patients with glottic insufficiency who underwent injection augmentation.

RESULTS

Among the patients who received their first injection augmentation with carboxymethyl cellulose and their second injection augmentation with calcium hydroxyapatite (n = 28), voice quality improved significantly after both injection augmentations. No significant differences were observed in any of the objective and subjective voice quality measurements examined following carboxymethyl cellulose and calcium hydroxyapatite injections.

CONCLUSION

Voice improvement after injection augmentation depends mainly on the improvement of glottic closure, rather than the injection material.

Thyrohyoid Approach for Vocal Fold Augmentation

Objectives:

I performed a retrospective chart review to evaluate the patient tolerance and clinical results of a new technique for office-based vocal fold augmentation.

Methods:

Ten patients undergoing the thyrohyoid approach for vocal fold augmentation were asked to rate their tolerance of the procedure using a 10-point rating scale (1 = “no problem” and 10 = “very uncomfortable”). The patients also filled out a quality-of-life survey (Voice Handicap Index-10) immediately before and 1 month after the procedure. I reviewed the preprocedure and postprocedure stroboscopic findings. The findings analyzed included changes in wave symmetry and glottal closure, and evidence of implant migration.

Results:

All patients successfully underwent the procedure. The mean patient tolerance score was found to be 2.1. The average score on the Voice Handicap Index-10 improved from 21.3 before the procedure (SD, 9.23) to 7.5 after the procedure (SD, 5.77). These values were compared by use of a paired t-test, and the difference was found to be significant, with a p value of .01. The analysis of stroboscopic results revealed “improvement” or “no change” in the wave symmetry, “improvement” in glottal closure, and “no evidence of migration” after the procedure in all cases.

Conclusions:

The study findings demonstrate that the thyrohyoid approach can be used successfully in patients who need vocal fold augmentation, and that it is generally well tolerated.

[Treatment of glottal gap]

Glottal gaps can be either physiological or pathological. The latter are multifactorial, predominantly organic in origin and occasionally functional. Organic causes include vocal fold paralysis or scarring, as well as a deficiency or excess of tissue. In addition to loss of the mucosal wave, the degree of hoarseness is primarily determined by the circumferential area of the glottal gap. It is thus important to quantify the extent of glottal insufficiency. Although a patient's symptoms form the basis for treatment decisions, these may be subjective and inadequately reflected by the results of auditory-perceptual evaluation, voice analysis and voice performance tests. The therapeutic approach should always combine phonosurgery with conventional voice therapy methods. Voice therapy utilises all the resources made available by the sphincter model of the aerodigestive tract and knowledge on the mechanism of voice production. The aim of phonosurgery is medialization, reconstruction or reinnervation by injection laryngoplasty or larynx framework surgery. These different methods can be combined and often applied directly after vocal fold surgery (primary reconstruction). In conclusion, the techniques described here can be effectively employed to compensate for glottal gaps.

Collagen injection for correcting vocal fold asymmetry: high-speed imaging

OBJECTIVES

We hypothesized that high-speed digital imaging with videokymographic and laryngotopographic analysis would provide a quantitative method to evaluate the effect of collagen injection for the correction of asymmetric and irregular vocal fold vibration in unilateral vocal fold paralysis.

METHODS

Videokymographic and laryngotopographic analysis was performed for high-speed digital recordings of vocal fold vibration for visualizing the glottal vibratory patterns, and for quantifying the frequency of vibration of each vocal fold, respectively, including comparisons between the paralyzed and normal vocal folds before and after surgery. This included prospective observations of 11 subjects with unilateral vocal fold paralysis (4 male, 7 female; mean +/- SD age, 67.1 +/- 12.0 years) using high-speed digital image analysis before and after collagen injection.

RESULTS

Analysis of the laryngotopographs revealed 2 distinct frequencies of vibration for the paralyzed and contralateral vocal folds for 8 of the 11 subjects before surgery. After collagen injection, the vibration frequencies became identical, despite asymmetric vibration amplitudes. Asymmetric vibration amplitudes were also observed in the other 3 subjects before surgery, but the amplitudes became symmetric after collagen injection, despite a persistent phase shift.

CONCLUSIONS

Asymmetric vibration in vocal fold paralysis was exemplified by differences in vibration frequency and amplitude between the vocal folds. The present study showed that after collagen injection, these aspects of vibratory patterns improved toward symmetry. This surgical procedure could improve the functional symmetry of the larynx for phonation.

Collagen Injection as a Supplement to Arytenoid Adduction for Vocal Fold Paralysis

Objectives:

Dysphonia associated with vocal fold paralysis can persist even after successful medialization procedures, including arytenoid adduction. It is hypothesized that laryngeal collagen injection could improve phonation following arytenoid adduction in selected patients. Our objective was to evaluate how collagen injection could result in measurable improvements in vocal function and voice quality.

Methods:

Forty patients with unilateral vocal fold paralysis who had undergone arytenoid adduction underwent transoral injection of non—cross-linked bovine dermal collagen by means of indirect laryngoscopy and a curved injection device. A control group of 40 patients underwent arytenoid adduction but not collagen injection. The patients' voice quality was assessed perceptually with the GRBAS scale, and vocal function was assessed by acoustic and aerodynamic measures (maximum phonation time and transglottal DC flow). The relative glottal area was also assessed by videostroboscopy.

Results:

Significant improvements in vocal function and voice quality were observed with collagen injection for those patients who did not achieve satisfactory glottal competence with arytenoid adduction alone. Glottal area measurements revealed that glottic insufficiency was significantly reduced after arytenoid adduction as well as after collagen injection.

Conclusions:

The findings suggest that collagen injection could be an effective supplementary treatment for improving voice following arytenoid adduction. It has the advantage of being a minimally invasive outpatient office procedure. The long-term efficacy of the procedure should be explored.

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.

The effect of surface electrical stimulation on vocal fold position

OBJECTIVES/HYPOTHESIS

Closure of the true and false vocal folds is a normal part of airway protection during swallowing. Individuals with reduced or delayed true vocal fold closure can be at risk for aspiration and may benefit from intervention to ameliorate the problem. Surface electrical stimulation is currently used during therapy for dysphagia, despite limited knowledge of its physiological effects.

DESIGN

Prospective single effects study.

METHODS

The immediate physiological effect of surface stimulation on true vocal fold angle was examined at rest in 27 healthy adults using 10 different electrode placements on the submental and neck regions. Fiberoptic nasolaryngoscopic recordings during passive inspiration were used to measure change in true vocal fold angle with stimulation.

RESULTS

Vocal fold angles changed only to a small extent during two electrode placements (P < or = .05). When two sets of electrodes were placed vertically on the neck, the mean true vocal fold abduction was 2.4 degrees; while horizontal placements of electrodes in the submental region produced a mean adduction of 2.8 degrees (P = .03).

CONCLUSIONS

Surface electrical stimulation to the submental and neck regions does not produce immediate true vocal fold adduction adequate for airway protection during swallowing, and one position may produce a slight increase in true vocal fold opening.

Evaluation of open approach and injection laryngoplasty inrevision thyroplasty procedures

INTRODUCTION: Vocal outcomes after medialization laryngoplasty are variable and may change over time. A revision procedure via open approach or an injection laryngoplasty may be necessary to improve vocal outcomes.

METHODS: A retrospective chart review was performed.

RESULTS: Twenty-nine subjects were identified and stratified into group 1A (n = 9) if the allograft was repositioned/replaced, group 1B (n = 4) if the allograft was removed, and group 2 (n = 16) if an injection laryngoplasty was performed. Statistically significant differences were found between all data prerevision to postrevision ( P ≤ 0.05) for group 1A and group 2 when multiple paired-sample t tests were calculated for patient-reported voice severity ratings and voice impact ratings as well as clinician-reported voice ratings of grade, roughness, and breathiness. Results of group 2 were often temporary, with 10 of 16 (62.5%) subjects receiving multiple injections.

CONCLUSION: Both open revision laryngoplasty and injection laryngoplasty are successful at providing improved vocal outcomes. Results are often temporary after injection laryngoplasty and often require multiple procedures.

Results with collagen injection into the vocal folds for medialization

PURPOSE OF REVIEW

This review outlines the indications, surgical techniques and follow-up, with results, for current collagen use.

RECENT FINDINGS

Micronized AlloDerm (Cymetra) is a presently available injectable substance made from human collagen and elastin particles. A mean follow-up of 8-10.5 months showed lasting results after injection for vocal fold immobility. Collagen injection is one possible method for treating a vocal fold scar - or sulcus -vergeture by medialization of one or both of the scarred vocal folds. Collagen injection laryngoplasty is presently the treatment of choice for presbyphonia if speech therapy is insufficient. Collagen injection for Parkinson-related dysphonia is an effective temporary method of subjectively improving voice and speech in selected patients. Laryngeal collagen injection can also permit further medialization of one or both vocal folds after medialization thyroplasty.

SUMMARY

Injection laryngoplasty with micronized AlloDerm, a presently available homologous collagen, remains a suitable option for the treatment of vocal fold immobility with a moderate gap. Collagen injection is also efficient for sulcus vergetures, scars and presbyphonia, and can help in cases of Parkinson's disease. Complications are uncommon but patients must be advised that the stability of results is unpredictable. Collagen injection can be repeated and does not prevent other surgical solutions.

Safety of percutaneous injection of bovine dermal crosslinked collagen for glottic insufficiency

OBJECTIVE

Our aim was to review the safety of percutaneous injection laryngoplasty using bovine crosslinked collagen, focusing specifically on two often-stated concerns: injecting patients who are taking the anticoagulant medication warfarin, and injecting patients without prior skin hypersensitivity testing.

STUDY DESIGN AND SETTING

Retrospective chart review of injection laryngoplasty performed between 1997 and 2006 at the University of California, Los Angeles.

RESULTS

The study group consisted of 895 patients who underwent 1290 injection laryngoplasty procedures. No bleeding complications were noted in 59 patients taking warfarin. No allergic complications were reported in 845 patients who did not undergo skin hypersensitivity testing before injection laryngoplasty.

CONCLUSION

Percutaneous bovine crosslinked collagen injection laryngoplasty is safe in patients taking warfarin. Skin testing for hypersensitivity does not appear to be necessary before injection.

SIGNIFICANCE

Patients on warfarin are candidates for injection laryngoplasty without the need to discontinue the medication. Eliminating skin hypersensitivity testing before percutaneous bovine crosslinked collagen injection laryngoplasty allows for a prompt treatment of glottic insufficiency.

Thyrohyoid Approach to Cidofovir Injection: A Case Study

Various techniques for injection into the larynx have been well described, including transoral injection with indirect laryngoscopy or direct laryngoscopy and transcutaneous injection through the thyroid cartilage or cricothyroid membrane. We describe a case not amenable to these techniques, in which entry through the thyrohyoid membrane for injection of cidofovir was successfully performed with a thyrohyoid approach. This technique is described, and comparisons are made with currently available techniques.

The role of glottal gap in predicting aspiration in patients with unilateral vocal paralysis

Aspiration has been frequently noted among patients suffering from vocal-fold paralysis. The association between a defect of glottal closure and aspiration in patients with unilateral vocal paralysis appears to have been rarely reported. The current study reviews collected data consisting of videotaped flexible nasoendoscopy and stroboscopy for patients with a unilateral vocal-fold paralysis. Mean normalized glottal gap areas for patients suffering vocal paralysis with associated aspiration are significant greater than that for the non-aspiration group. Subsequent to the surgical correction of the glottal gap, all patients recovered well from their earlier aspiration. The investigation of objectively derived data revealed that poor airway protection due to incomplete closure of the vocal fold was the major cause of aspiration for patients suffering unilateral vocal-fold paralysis. Intracordal autologous fat injection can successfully improve the breath control and eliminate aspiration in patients with vocal-fold paralysis.

Evidence-based treatment of paralytic dysphonia: making sense of outcomes and efficacy data

The criteria used to determine the success or failure of a given treatment for vocal fold paralysis are fundamental components of routine clinical practice and treatment outcomes research for the surgeon and voice therapist. The purpose of this article is to offer a guide to the critical interpretation of available measures of out-come and efficacy for this patient population. Such data form the basis for the practice of evidence-based medicine and voice therapy,essential if the standard of care is to evolve to the benefit of the patient. A better understanding of the potentials and limitations of each measure is important for treatment planning and patient counseling and, ultimately, for the conception of future well-designed clinical research. The complex issues regarding outcomes measurement are addressed here within the context of current treatment literature on vocal fold paralysis. Particular emphasis is placed on realistic data gathering within clinical practice.