Vocal mechanics as the basis for phonosurgery

Subtotal Submucosal Arytenoidectomy with Lateralization Sutures (SMALS) Covered by a Mucosal Flap

OBJECTIVE

Glottic airway stenosis (GAWS) may result from bilateral paralysis (BVFP) or posterior glottic stenosis (PGS). Since the glottis is the principal airway sphincter, surgeons shift on the balance between airway, aspirations, and voice. We aim to describe our surgical technique and outcome of the SMALS procedure for GAWS correction.

METHODS

A retrospective cohort of patients who underwent SMALS for PGS between 2018 and 2021. SMALS involves: endoscopic submucosal subtotal arytenoidectmy (preserving medial mucosal flap) and lateralization sutures. The sutures lateralize the mucosal flap to cover the arytenoidectomy bed without lateralization of the membranous vocal fold; expanding the posterior glottis, while preserving a relatively good voice. Covering the arytenoidectomy bed enhances healing. Medical and surgical data, airway, voice, and swallowing symptoms were collected. Relative glottic opening area (RGOA) and relative glottic insufficiency area (RGIA) were calculated.

RESULTS

Eleven PGS patients who underwent 15 SMALS were included (4 bilateral), all patients had post-intubation PGS, 1 patient also had prior radiation to the larynx. All patients were tracheostomy-dependent. There were no major complications. No granulation or retracting scar was observed at follow-up. None had a persistent voice or swallowing disability. Successful outcome (decannulation) was achieved in 8 (73%); RGOA increased in all (Δ = 0.37; p = 0.003), while RGIA remained relatively stable (Δ = 0.02; p = 0.055).

CONCLUSIONS

SMALS is a safe and effective, novel modification of the classic arytenoidectomy, for GAWS correction that can be easily applied and may expand the airway without significant glottic insufficiency symptoms.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:353-360, 2024.

Control of Pre-phonatory Glottal Shape by Intrinsic Laryngeal Muscles

OBJECTIVES

Surgical manipulations to treat glottic insufficiency aim to restore the physiologic pre-phonatory glottal shape. However, the physiologic pre-phonatory glottal shape as a function of interactions between all intrinsic laryngeal muscles (ILMs) has not been described. Vocal fold posture and medial surface shape were investigated across concurrent activation and interactions of thyroarytenoid (TA), cricothyroid (CT), and lateral cricoarytenoid/interarytenoid (LCA/IA) muscles.

STUDY DESIGN

In vivo canine hemilarynx model.

METHODS

The ILMs were stimulated across combinations of four graded levels each from low-to-high activation. A total of 64 distinct medial surface postures (4 TA × 4 CT × 4 LCA/IA levels) were captured using high-speed video. Using a custom 3D interpolation algorithm, the medial surface shape was reconstructed.

RESULTS

Combined activation of ILMs yielded a range of unique pre-phonatory postures. Both LCA/IA and TA activation adducted the vocal fold but with greater contribution from TA. The transition from a convergent to a rectangular glottal shape was primarily mediated by TA muscle activation but LCA/IA and TA together resulted in a smooth rectangular glottis compared to TA alone, which caused rectangular glottis with inferomedial bulging. CT activation resulted in a lengthened but slightly abducted glottis.

CONCLUSIONS

TA was primarily responsible for the rectangular shape of the adducted glottis with synergistic contribution from the LCA/IA. CT contributed minimally to vocal fold medial shape but elongated the glottis. These findings further refine laryngeal posture goals in surgical correction of glottic insufficiency.

LEVEL OF EVIDENCE

N/A, Basic science Laryngoscope, 2022.

Long-Term Effects of Fat Injection Laryngoplasty in Relation to the Injected Fat Volume in Patients With Unilateral Vocal Fold Paralysis

OBJECTIVE

To evaluate the improvements in vocal function and glottal form before and after autologous fat injection laryngoplasty in relation to the injected total fat volume in patients with unilateral vocal fold paralysis.

DESIGN

Clinical study.

METHODS

Seventy-three patients with unilateral vocal fold paralysis received fat injection laryngoplasty and were divided into low-volume injection (<3 mL; average, 2.0 mL) and high-volume injection (≥3 mL; average, 4.3 mL) groups. Voice function before and after fat injection laryngoplasty were examined by aerodynamics evaluations, pitch and intensity measurements, and acoustic analyses. The glottal form before and after fat injection laryngoplasty was determined by measuring the ratio of vocal fold bowing (bowing ratio) and the ratio of lengths between bilateral vocal process (width ratio) at an easy phonation under laryngeal endoscopic examination. The postoperative parameters were evaluated for a median period of four years after fat injection laryngoplasty. The differences between pre- and postoperative parameters were examined separately for each group by the paired t-test. For each variable, a comparison of the effects of surgery was conducted using an analysis of covariance model with the change between the pre- and postoperative values as a dependent variable and the preoperative value as a covariate.

RESULTS

In both groups, all parameters of voice function and glottal form after surgery significantly improved in comparison to those before surgery. Maximum phonation time, amplitude perturbation quotient, and normalized noise energy for 0 to 4 kHz in the high-volume group improved more significantly in comparison to those in the low-volume group.

CONCLUSIONS

As a rough guide for males, injection of more than 3 mL of autologous fat to the vocal muscle layer is recommended for reliable improvement of voice function in patients with unilateral vocal fold paralysis.

One hundred years of external approach medialisation thyroplasty

It has been 100 years since Erwin Payr first developed an operation to improve the effects of a paralysed vocal fold, and operations based on this technique are still in use today. This technique, medialisation thyroplasty, aims to improve the symptoms caused by vocal fold palsy by realigning the lateralised vocal fold into the midline.

Whilst the effects of vocal fold palsy were recognised in antiquity, it was only with the development of indirect laryngoscopy in the late nineteenth century that the vocal fold paralysis could be identified as an aetiology for poor phonation and dysphagia. Payr, in 1915, was the first to perform a recognisable form of medialisation thyroplasty, which was further developed in the early twentieth century, but medialisation thyroplasty did not begin to be widely used until the development of the modern technique by Isshiki et al., in 1974.

Since then, medialisation thyroplasty has continued to be developed and is currently the most widely used technique for correcting the effects of vocal fold palsy. However, a wide array of therapeutic options is now available for vocal fold palsy and it is impossible to say whether or not medialisation thyroplasty will still be used in another 100 years.

Control of the glottal configuration in ex vivo human models: quantitative anatomy for clinical and experimental practices

INTRODUCTION

The objective of this paper was to identify the determining factors of the glottal prephonatory configuration from the point of view of the resulting muscular actions (i.e., arytenoids adduction, membranous vocal fold adduction, and tension).

MATERIALS AND METHODS

21 human non-embalmed excised larynges (12 females and 9 males) were studied. Experiment A (11 larynges) studied four conditions of adduction of the vocal folds and arytenoids. Experiment B (10 larynges) studied the effect of cricothyroid approximation on the vocal fold length and the cricothyroid angle.

RESULTS

Experiment A: The mean glottal area significantly decreased from 41.2 mm² mean with no adduction, to 10.2 mm² mean with arytenoid adduction, to 9.2 mm² with membranous vocal fold adduction, and down to 1.1 mm² with the combination of arytenoid and membranous adduction. The effect of the task was statistically significant. Experiment B: The length of vocal folds increased from 13.61 mm median to 14.48 mm median, and the cricothyroid angle decreased of 10.05 median along with cricothyroid approximation.

DISCUSSION

The results of experiment A emphasize the sub-division of adductor intrinsic muscles in arytenoids adductors (i.e., LCA and IA), and membranous vocal fold adductor (i.e., TA). The results of experiment B quantify the effect of cricothyroid approximation on the vocal folds length. The implications of these results can be useful in both clinical practice and experimental studies.

A comparison between transoral glottis-widening techniques for bilateral vocal fold immobility

OBJECTIVE

Comparison of different endoscopic glottis-widening procedures designed for bilateral vocal cord immobility (BVCI) is a challenge. This is because a statistically efficient analysis and comparable clinical series is hard to obtain considering the variable aspects of the results and the evaluation methods. This study of a large number of cadaver larynges provides comparable, objective data for the evaluation of the possible postoperative breathing and voicing function.

STUDY DESIGN

A morphometric study was performed on 50 male and 50 female larynges to compare the different suture lateralization and resection procedures.

METHODS

The postoperative characteristic of glottic configuration was evaluated following vocal cord laterofixation, endolaryngeal arytenoid abduction lateropexy (EAAL), Schobel's external lateralization procedure (SELP), transverse cordotomy (TC), and medial and total arytenoidectomies (AE). The glottic area and the parameters determining the phoniatric outcomes were assessed by a digital image analyzer program.

RESULTS

Improvement of glottic area was observed after all procedures, but arytenoid abduction procedures were significantly the most effective. However, the smallest vocal cord angles were found in TC and AE; the injury of the voicing structures results in a deterioration of vocal mechanics and can be reasonably assumed to negatively influence the voice. Endolaryngeal arytenoid abduction lateropexy and SELP may provide the best phonation closure when residual adduction regeneration can occur.

CONCLUSION

This study demonstrates the complexity of the correct surgical decision making in BVCI. Procedures that utilize physiological abduction of the arytenoid cartilage seem to be more advantageous, especially if recovery of adductor function occurs.

LEVEL OF EVIDENCE

N/A.

Framework Surgery for Treatment of Unilateral Vocal Fold Paralysis

Laryngeal framework surgery is the current gold standard treatment for unilateral vocal fold paralysis. It provides a permanent solution to glottic insufficiency caused by injury to the recurrent laryngeal nerve. Various modifications to the original Isshiki type I laryngoplasty procedure have been described to improve voice and swallowing outcomes. The success of this procedure is highly dependent on the experience of the surgeon as it epitomizes the intersection of art and science in the field. The following article reviews the evidence, controversies, and complications related to laryngoplasty for unilateral vocal fold paralysis. It also provides a detailed analysis of how and when arytenoid-positioning procedures should be considered, and summarizes the literature on postoperative outcomes.

Medialization thyroplasty using autologous nasal septal cartilage for treating unilateral vocal fold paralysis

Objectives

A persistent insufficiency of glottal closure is mostly a consequence of impaired unilateral vocal fold movement. Functional surgical treatment is required because of the consequential voice, breathing and swallowing impairments. The goal of the study was to determine the functional voice outcomes after medialization thyroplasty with using autologous septal cartilage from the nose.

Methods

External vocal fold medialization using autologous nasal septal cartilage was performed on 15 patients (6 females and 9 males; age range, 30 to 57 years). Detailed functional examinations were performed for all the patients before and after the surgery and this included perceptual voice assessment, laryngostroboscopic examination and acoustic voice analysis.

Results

All the patients reported improvement of voice quality post-operatively. Laryngostroboscopy revealed almost complete glottal closure after surgery in the majority of patients. Acoustic and perceptual voice assessment showed significant improvement post-operatively.

Conclusion

Medialization thyroplasty using an autologous nasal septal cartilage implant offers good tissue tolerability and significant improvement of the subjective and objective functional voice outcomes.

Surgical tips for type II thyroplasty for adductor spasmodic dysphonia: modified technique after reviewing unsatisfactory cases

CONCLUSION

Use of the titanium bridge, both at the top and bottom corners of the incised thyroid cartilage, is essential for success. Most importantly, these procedures should be done with minimal damage to the tissues involved, using fine instruments.

OBJECTIVES

Type II thyroplasty that aims at lateralization of the vocal folds for spasmodic dysphonia is a type of surgery that requires utmost surgical caution, because of the extremely delicate site for surgical intervention, critically sensitive adjustment, and difficult procedures to maintain the incised cartilages in a correct position.

PATIENTS AND METHODS

By means of a postoperative questionnaire and examinations, analyses were made of the relation in each case between the detailed surgical records and the outcomes in terms of subjective complaints, vocal features, and laryngeal as well as aerodynamic findings.

RESULTS

It was found that surgical failures or unsatisfactory results arise most frequently from certain clear mechanical faults. The critical procedures that most affected the results included: (1) incision and separation of the thyroid cartilage at the midline; (2) adjustment of separation width for optimal voice; (3) cartilage-perichondrium separation for holding an appropriate titanium bridge; and (4) installation and fixation of titanium bridges.

Over-injection of autologous fat in the vocal fold: how to remove the excess?

Chordal injection of autologous fat is useful in treating incomplete closure of the glottis on phonation, because it is simple, uses an intraoral approach and is mostly effective. However, when excess fat is injected, the removal of the excess is generally much more difficult than the injection. A 48-year-old man underwent intrachordal injections of autologous fat twice bilaterally for vocal fold atrophy. He came to our hospital because his hoarseness became worse after every operation. Three-dimensional computed tomography revealed that a large amount of fat was injected in the bilateral subglottal and glottic regions. These findings indicated that his dysphonia was due mainly to the excessive injected fat, and removal of the fat was planned. Under local anesthesia, we partially removed the excess fat through a window made in the thyroid cartilage, without touching the vocal folds. The voice and laryngeal findings were monitored during the surgery according to fiber-stroboscopic findings. Postoperatively, a significant improvement was seen in the voice and vibration of the vocal folds, although the results were not completely satisfactory.

Autologous Transplantation of Fascia into the Vocal Fold: Long-Term Result of Type-1 Transplantation and the Future

OBJECTIVES

Since 1997, we have performed the autologous transplantation of fascia into the vocal fold (ATFV) procedure on cases of sulcus vocalis. In what follows, we report the long-term results of our new surgical approach and discuss the role of these transplantations. We also review and report some complications that can be caused by ATFV. Finally, we discuss the ATFV technique as a contribution to the phonosurgery of the future.

STUDY DESIGN

Prospective study.

METHODS

We were able to obtain long-term results from 10 volunteer cases (2 female and 8 male, age: 15-71, mean 46.5 years old) who could be followed up for at least 3 years after transplantation. All were cases of pathologic sulcus vocalis.We measured maximum phonation time (MPT) and carried out pre- and postsurgical clinical observation and laryngeal stroboscopy in all cases. These measurements and observations were made before the ATFV and at 6 months, 1 year, 2 years, and 3 years after surgery.

RESULTS

In stroboscopic observation 1 year after the ATFV, satisfactory glottal closure and excellent mucosal wave were observed for all cases, and there was no case with hyperadduction of the false vocal folds. MPT measures remained at an improved level 2 years and 3 years after the transplantations. Paired-sample t tests showed that the improvement relative to preATFV levels was significant for all postsurgical measurements up to 3 years.

CONCLUSIONS

We conclude that ATFV is a successful surgical procedure for sulcus vocalis and scarred vocal folds. Other phonosurgical clinical applications may also be envisioned.

Functional outcome of vocal fold medialization thyroplasty with a hydroxyapatite implant

OBJECTIVES

Unilateral vocal fold paralysis can cause a persistent incomplete glottal closure during phonation, resulting in impaired voice function. The aim of this study was to evaluate functional results of medialization thyroplasty using a hydroxyapatite implant (VoCoM).

STUDY DESIGN

Prospective observational cohort study.

METHODS

Between 1999 and 2003, a total of 26 patients (19 men, 7 women) undergoing medialization thyroplasty using a hydroxyapatite implant because of unilateral vocal fold paralysis were enrolled in the study. To evaluate voice function, the following parameters were measured preoperatively and postoperatively: mean fundamental frequency, mean sound pressure level, frequency and amplitude range (voice range profile), and maximum phonation time. A perceptual assessment of hoarseness was conducted using the Roughness, Breathiness, Hoarseness scale. Furthermore, the magnitude of voice related impairment of the patient's communication skills was rated on a 7-point scale. A combined parameter called the Voice Dysfunction Index (VDI) was used to rate vocal performance.

RESULTS

All patients showed a statistically significant improvement in the VDI, in perceptual voice analysis, in maximum phonation time, and in the dynamic range of voice. One patient experienced a postoperative wound hemorrhage as a minor complication. No further complications or implant extrusions were observed.

CONCLUSIONS

Medialization thyroplasty using a hydroxyapatite implant is a secure and efficient phonosurgical procedure. Voice quality and patient satisfaction improve significantly after treatment.

[Therapy for unilateral vocal fold palsy]

The main symptom of unilateral vocal fold palsy is hoarseness, which can cause considerable disturbance to the patient depending on its extent and the patient's individual situation. Therapy aims at the restitution of a tuneful and resilient voice, which can be achieved by surgical or conservative means, improving the glottal closure and synchronizing the vocal fold vibrations during phonation. Vocal therapy is a common conservative method that may be supported by psychotherapeutic or physical procedures. In surgical therapy, there is a distinction between techniques of endoscopic augmentation by injecting different materials into the vocal folds and transcutaneous laryngeal framework surgery, i.e., transferring the paralyzed vocal fold to the glottal midline. Particularly apt for injection are biocompatible materials amount and position whose can easily be controlled. However, the inevitable resorption of many materials causes deterioration in voice quality. Furthermore, the change of vocal fold morphology obstructs regular phonatory vibration. On the other hand, medialization thyroplasty leads to permanent voice amelioration without a substantial complication rate when performed by experienced surgeons.

Long-term results of type II thyroplasty for adductor spasmodic dysphonia

OBJECTIVES

To assess the outcome of type II thyroplasty in the treatment of adductor spasmodic dysphonia (ASD).

STUDY DESIGN

Prospective case series.

METHODS

Thirteen patients with the diagnosis of ASD who were previously treated successfully with botulinum toxin therapy were recruited. Type II thyroplasty as described by Nobuhiko Isshiki was performed on all the patients. A self-rating assessment of the degree of severity and vocal effort were recorded and compared preoperatively and during postoperative follow-up.

RESULTS

There were four early failures in our series, with two caused by friable thyroid cartilage. In the early postoperative period, after excluding the early failures, six (66.7%) and seven (77.8%) patients had moderate-good improvement in symptom severity and vocal effort, respectively. During the follow-up period, a further five patients had deterioration of voice quality and were classified as failures. Of these five patients, two patients had reversal of their procedure. At the end of the follow-up period (mean follow-up period of 12 months), six (66.7%) and five (55.5%) patients sustained improvement in symptom severity and vocal effort, respectively. However, only two (22.2%) and three (33.3%) patients had moderate-good improvements in symptom severity and vocal effort, respectively, after 12 months.

CONCLUSIONS

Botulinum toxin injection remains the gold-standard treatment for ASD in our center. Potential patients for type II thyroplasty need to be carefully selected and counseled by a multidisciplinary team of otolaryngologists, neurologists, and speech pathologists.

Type 2 thyroplasty for spasmodic dysphonia: fixation using a titanium bridge

OBJECTIVE

In order to facilitate surgery for spasmodic dysphonia, i.e. type 2 thyroplasty, a device was designed to fix the incised edges of the thyroid cartilage firmly.

MATERIAL AND METHODS

Various types and sizes of titanium bridge were developed for clinical use.

RESULTS

The results of surgery for spasmodic dysphonia were satisfactory in all 10 cases in which the new titanium bridge was used. No complications have been encountered to date.

CONCLUSION

Type 2 thyroplasty for spasmodic dysphonia was made easier to perform using the new titanium bridge, and more stable fixation of the reconstructed thyroid cartilage was achieved.

Cricothyroid Approximation and Thyroid Chondroplasty: A Patient Survey

OBJECTIVE: Cricothyroid approximation is performed in male-to-female transsexuals to raise the pitch of the voice often accompanied by a thyroid chondroplasty, an aesthetic reduction of the thyroid cartilage. The survey was conducted to ascertain patient satisfaction with the procedures.

STUDY DESIGN AND SETTING: Fifty-four patients had the procedures performed in our department over an 8-year period; 45 patients were sent postal questionnaires to evaluate patient satisfaction with the appearance of the laryngeal prominence, pitch of the voice, and which they found more beneficial, the surgery or speech therapy.

RESULTS: A response rate of 93% was obtained; 86% of patients thought their laryngeal profile had improved, 79% thought their voice had improved, and 55% thought that surgery and 21% thought that speech therapy had helped more in improving the voice. Overall, 79% were satisfied with the results of the surgery.

CONCLUSIONS: Cricothyroid approximation and thyroid chondroplasty have a high patient satisfaction rate.

Minifenestration type I thyroplasty using an expanded polytetrafluoroethylene implant

Several methods have been used to treat laryngeal incompetence, but no ideal technique has been identified. This paper describes a clinical experience with minifenestration type I thyroplasty using a new device made of expanded polytetrafluoroethylene (ePTFE). The device, a thin ribbon of ePTFE, is inserted through a 4-mm fenestration to produce vocal fold medialization. At our center, 26 of these devices have been implanted in the past 3 years. Good or satisfactory results were achieved in 96% of cases. Advantages of this technique include easy insertion of the implant, nominal cost and biocompatibility of the ePTFE device, ready availability of all instruments required for the procedure, and elimination of the need to perform arytenoid adduction.

Anterior and posterior medialization (APM) thyroplasty

OBJECTIVE

In unilateral vocal fold paralysis with dysphonia, most of the paralyzed vocal folds may be medialized effectively by medialization laryngoplasty. However, if the posterior glottal gap is wide, these procedures may sometimes have a limit to medialize the posterior glottis and cannot be effective for acceptable voice quality. The objective of this study is to introduce a new surgical technique for medializing the membranous and cartilaginous portions of the paralyzed vocal fold: anterior and posterior medialization (APM) thyroplasty.

METHOD

Six patients underwent APM thyroplasty. They completed preoperative and postoperative evaluation with acoustic analysis and video laryngoscopy.

RESULTS

All patients satisfied their voice subjectively after surgery. The paralyzed vocal folds, membranous and cartilaginous parts, were medialized well, and the paralyzed arytenoid showed less anterior tipping postoperatively. On voice analysis all patients showed prolonged phonation times and decreased perturbations after surgery.

CONCLUSION

The advantages of this procedure are to medialize the membranous and cartilaginous portions of the paralyzed vocal fold directly and to correct vertical mismatch between two vocal folds. This procedure might be especially indicated in the lateralized position of the paralyzed vocal fold but not in the higher paralyzed vocal fold compared with the normal vocal fold.

Thyroplasty for adductor spasmodic dysphonia: further experiences

OBJECTIVES

Two different surgical techniques for midline lateralization thyroplasty (type 2 thyroplasty) for adductor spasmodic dysphonia (SD) have been described, one using a composite graft and the other without. Indications and results for each method among different types of SD were compared, together with the theoretical background for the surgery.

STUDY DESIGN

Retrospective.

METHODS

The medical records of six patients with SD together with the fiberscopic video recording of laryngeal findings before, during, and after surgery were reviewed. The intraoperative video recordings of the surgical procedures were compared with the postoperative findings.

RESULTS

The vocal features of SD, diverse preoperatively, disappeared postoperatively and a normal, or almost normal, voice was attained in 5 of 6 cases. The failure in one patient was attributed to combined focal dystonia of the neck muscles and difficulty in lateralization. Type 2 thyroplasty without a graft, which causes bowing of both vocal folds, is simple to perform and effective enough for most SD cases. No recurrence has been noted so far over postoperative periods ranging from 6 months to more than 3 years.

CONCLUSION

The results suggest that thyroplasty is an effective therapeutic approach for SD.

Concomitant type I thyroplasty and thoracic operations for lung cancer: preventing respiratory complications associated with vagus or recurrent laryngeal nerve injury

OBJECTIVES

We sought to prevent postoperative swallowing disorder, aspiration, and sputum retention in cases of recurrent laryngeal or vagus nerve section occurring during lung cancer resection.

METHODS

In 14 of 25 consecutive patients, type I thyroplasty and thoracic operations were performed during the same period of anesthesia. All patients had a preoperative laryngeal computed tomographic scan providing us with indispensable measurements for vocal fold medialization under general anesthesia (ie, without intraoperative phonatory control). Nine remaining patients had a type I thyroplasty delayed from thoracic operations because of intraoperative doubt about laryngeal innervation injury, and 2 did not need a laryngeal operation. Main postoperative records consisted of swallowing ability, respiratory complications, and quality of voice.

RESULTS

No swallowing disorder, aspiration, or sputum retention occurred in cases of concomitant laryngeal and thoracic operations. Of these 14 patients, a single case (7%) of major complication (vocal fold overmedialization) occurred and required an early and successful revision thyroplasty; one case of cervical hematoma that did not require surgical drainage was considered a minor complication (7%). Twelve (86%) patients who underwent the concomitant association of both operations were fully satisfied with their quality of voice.

CONCLUSIONS

Type I thyroplasty and thoracic operation can be advantageously associated in case of injury to laryngeal motor innervation to prevent postoperative swallowing disability and dramatic respiratory complications.

Progress in laryngeal framework surgery

This paper reviews progress in laryngeal framework surgery since it was first reported about 25 years ago. The success of this type of surgery requires both a basic knowledge of the physiology of phonation, in order to make decisions about the surgical procedure, and surgical skill, in order to accomplish the intended procedure successfully. The main reason for hoarseness is imperfect closure of the glottis, but the second most important reason for hoarseness, increased stiffness of the vocal fold, cannot be corrected by mere medialization of the vocal fold. Laryngeal framework surgery is different in concept from conventional surgery, which is intended to remove the lesion. Controversial points discussed here regarding type I thyroplasty include: (i) whether the cartilage window should be removed; (ii) materials for fixation of the window; and (iii) comparison of type I thyroplasty with arytenoid adduction. A new surgical treatment for spasmodic dysphonia and its results in three patients are described briefly. Surgery for raising the vocal pitch requires further improvement. In the future, laryngeal framework surgery will have wider application in treatment of dysphonias, such as asthenic voice due to atrophy in professional singers or aging, pitch problems in females and gender identity disorder and spasmodic dysphonia.

Midline lateralization thyroplasty for adductor spasmodic dysphonia

Midline lateralization thyroplasty was successfully performed on a patient with adductor spasmodic dysphonia. The thyroid cartilage was incised at the midline, and a 3 x 2-mm perforation was made at the anterior commissure to widen it. The perforation was closed with a free composite graft taken from the upper edge of the thyroid ala, and the incised thyroid cartilage edges were kept separated 4 mm apart with silicone wedges. A part of the sternohyoid muscle was rotated to seal any leak from the perforation. The postoperative course was uneventful. The voice has been restored to normal, and there is no sign of recurrence of the symptom so far, as of 1 year 5 months postoperative. Although a longer follow-up is needed, this case indicates that midline type II thyroplasty could be a useful treatment for adductor spasmodic dysphonia.

Advances and refinements in phonosurgery

Scientific discovery, technological advances, and improved outcomes assessment have resulted in advances and refinements in phonosurgery. Three areas of substantial evolution are phonomicrosurgery, laryngeal framework surgery, and the use of implantable materials in vocal folds. Discovery of the importance of the superficial layers of the lamina propria has led to increased use of more limited medial microflap approaches and less frequent use of the classic lateral cordotomy flap approach. Alternative approaches to managing vocal fold scarring defects have addressed the separation of body and cover and provided suitable lamina propria replacement. Approaches to sulcus vocalis have been refined to address type II (linear vergeture) and type III (focal invasive pit) sulcus, where there is loss of lamina propria, while still recognizing the common nonpathological type I (physiological) sulcus. Technological advancements such as photodynamic therapy, tuned dye lasers, and laryngeal microdebridement have augmented the armamentarium for mechanical removal of laryngeal papillomata. Careful infusion-assisted microexcision and adjunctive medical management have been refined and made more effective. Laryngeal framework surgery has embraced the development of Silastic, hydroxylapatite, expanded polytetrafluoroethylene, and titanium shims. Anatomical studies have helped to improve operative precision and safety, and have led to inventive variations in arytenoid repositioning that improve closure of the posterior subunit. Vocal fold augmentation by injection has been facilitated by innovative use of the rigid telescope and intraoperative videostroboscopy. Anatomical studies have focused on the infrafold region and rheological studies have attempted to match viscoelastic properties of injectable substances to those of vocal fold tissues. Alloplastic materials such as Teflon have been largely supplanted by newer bioimplantables such as fat, collagen, and fascia.