Anterior Glottic Web Formation for Voice Feminization - Experience of 27 Patients

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Anterior Glottic Web Formation for Voice Feminization: Experience of 27 Patients Taner Yılmaz, Og˘uz Kus¸çu, Tevfik Sözen, and Ahmet Emre Süslü, Ankara, Turkey Summary: Objective. Voice feminization is needed for male-to-female transsexuals, males with testicular feminization, and females with constitutional androphonia. Anterior glottic web formation affords advantages: endoscopic surgery without skin incision and scar, outpatient surgery, potential reversibility, and low risk for vocal fold and airway damage. Study Design. This is a nonrandomized prospective cohort study. Setting. University hospital. Materials and Methods. All 27 cases of androphonia were treated with endoscopic anterior glottic web formation. Voice Handicap Index (VHI-30); acoustic analysis with /a/ including F0, jitter, shimmer, noise-to-harmonic ratio; and acoustic analysis of connected speech for speaking F0 were determined pre- and postoperatively. Patients and medical students rated pre- and postoperative voices as feminine, masculine, or neither. Results. The pre- and postoperative mean total VHI scores of patients were 38 and 24, respectively; this difference was statistically significant (P < 0.001). Their pre- and postoperative mean F0 and speaking F0 were 152 and 158 and 195 and 200 Hz, respectively; these differences were statistically significant (P < 0.001). Their pre- and postoperative acoustic analysis results were not significantly different (P > 0.05). Seven patients (26%) needed laser reduction glottoplasty for voice feminization because they were not satisfied with the voice result. Patients’ self-evaluations of their postoperative voice revealed 20 feminine, 2 masculine, and 5 neither results, giving a rise to patient satisfaction rate of 74%. Medical students rated 85% of postoperative voice samples as feminine, giving rise to overall success rate of 85%. Conclusion. Anterior commissure web formation is a successful surgical option for voice feminization. However, additional surgery may be necessary for patient satisfaction. Key Words: Voice–Feminization–Vocal cords–Transsexualism–Transgender persons.

INTRODUCTION Male-to-female transsexuals (MFTs), males with testicular feminization who were raised as females, and females with constitutional androphonia seek medical help for their lowfrequency male voice. Males with testicular feminization are genotypically XY patients with female secondary sexual characteristics because of complete or partial androgen insensitivity. Patients with partial androgen insensitivity have ambiguous genitalia and testes; these patients attain male voice characteristics before their gonads are removed to be raised as females. Constitutional androphonia is seen in normal females without any apparent androgen source; some of these ladies may have polycystic ovarian syndrome. There are multiple treatment options for voice feminization. Most of these options are surgical treatments. Voice therapy is the only nonsurgical choice. Cricothyroid approximation,1 anterior commissure advancement,2,3 and feminization laryngoplasty4 are external surgical procedures; therefore, they result in skin

incision and scar. On the other hand, anterior glottic web formation5 and laser reduction glottoplasty6,7 are endoscopic procedures that do not result in skin incision. All of these surgeries produce a feminine voice with potential advantages and disadvantages. A voice surgeon needs to have multiple surgical options for voice feminization in his armamentarium, because many, but not all, patients are not satisfied with the postoperative voice result and ask for a more feminine voice. An ideal surgical procedure for raising vocal pitch should be reliable, with little or no morbidity, and permit the individual to use a normal intent and effort when speaking with an F0 higher than 165 Hz to be perceived as female.8 However, our experience shows that speaking with F0 = 165 Hz is usually not enough and a higher F0 is necessary to be perceived as feminine. The authors would like to present their endoscopic anterior glottic web formation technique for voice feminization and their experience on 27 patients, and discuss the potential advantages and disadvantages of this surgical procedure.

Accepted for publication March 13, 2017. Financial Disclosure: The study was financially supported by a Hacettepe University Research Fund. Conflict of interest: None. This paper was presented on podium at the ALA section of COSM, May 18–22, 2016, Chicago, IL, USA. From the Department of Otolaryngology-Head & Neck Surgery, Hacettepe University Faculty of Medicine, Ankara, Turkey. Address correspondence and reprint requests to Taner Yılmaz, Department of Otolaryngology-Head & Neck Surgery, Hacettepe University Faculty of Medicine, 06100 Sıhhiye, Ankara, Turkey. E-mail: [email protected] Journal of Voice, Vol. 31, No. 6, pp. 757–763 0892-1997 © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jvoice.2017.03.006

MATERIALS AND METHODS This study was approved by the institutional ethics committee of our university (number GO 15/710). The study was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study. This is a nonrandomized prospective cohort study, performed at a tertiary referral center, which is a university hospital. All 27 consecutive cases of androphonia, who applied to our

758 department between 2010 and 2015, were treated with endoscopic anterior glottic web formation and followed for at least 1 year postoperatively. All of the patients lived far away from the city where our hospital was located, so they were unable to attend voice therapy sessions; that is why voice therapy option was not used. Twenty-one patients were male-to-female transsexuals, three were males with testicular feminization, and three were females with constitutional androphonia. Their ages ranged between 14 and 50, with a mean of 29 and standard deviation of 8.1. None of the patients received pre- or postoperative voice therapy. All patients underwent preoperative psychological evaluation before undergoing surgery. They all had stable psychological condition. Voice Handicap Index (VHI-30), including physical, functional, emotional, and total scores, was performed preoperatively and 1 year postoperatively on all patients. Acoustic analysis with /a/ at comfortable pitch and loudness using Computerized Speech Lab Model 4300B (Kay Elemetrics, Lincoln Park, NJ, USA) including Fo (Hz), jitter (%), shimmer percent (Shim) (%), noise-to-harmonic ratio (NHR), and speaking F0 using Analysis of Dysphonia in Speech and Voice was performed preoperatively and 1 year postoperatively on all patients. Surgical technique (Video S1) The operations were performed by a senior author (TY) under general anesthesia with endotracheal intubation. Size B or C Kleinsasser laryngoscope (Storz, Tütlingen, Germany) was inserted into the patient’s larynx and suspended. Anterior commissure must be visualized during microlaryngoscopy; therefore, when necessary, anterior pressure was applied to larynx with adhesive tapes, the ends of which were fixed to operation table. The vocal folds were examined under appropriate magnification with microscope and were palpated with blunt instruments to determine any vocal fold lesion missed during videolaryngostroboscopic examination. Nothing was injected to the vocal folds for hemostasis before surgery. The anterior half of membranous vocal folds was determined. The mucosa of the posterior end of the anterior half of membranous vocal fold was grasped with microlaryngeal forceps and pulled medially. With appropriate microscissors, this mucosa was stripped from the free border of vocal fold toward anterior commissure. The same stripping was repeated on the opposite side. The stripped vocal fold mucosa was removed from anterior commissure with microscissors. Epinephrine was applied with cotton-tipped applicator to the surgical wound for hemostasis. To form anterior glottic web, the denuded vocal folds were sutured to each other. Suturing started at the anterior commissure. The most-difficultto-perform suture was the one at the anterior commissure; suturing became easier as the surgeon moved posteriorly. Two nonlocking microlaryngeal straight forceps and a knot pusher were utilized during suturing. 5/0 vicryl suture with 11-mm-long, reversecutting, curved needle with at least 45 cm thread length was used. The needle was first passed through the right vocal fold from inferior surface to superior surface; then the needle pierced the left vocal fold from superior to inferior surface. The suture was tied to place a single knot subglottically. Usually three to four sutures, sometimes five sutures, were used to bring denuded vocal

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FIGURE 1. Endoscopic view of glottis before starting web surgery. folds together and to create anterior glottic web9,10 (Figures 1–3). Tissue adhesives have never been used. There were 2.5 units of botulinum toxin A injected to each vocalis muscle to ensure involuntary voice rest. Patients were advised postoperative complete voice rest for 7 days. Postoperative medication was not given. The patients were asked to rate their postoperative voice as feminine, masculine, or neither. The pre- and postoperative connected speech samples of patients were mixed stored randomly in a voice file and played in the class of 25 fifth year medical students who never had any education about voice evaluation; they were asked to rate the patients’ voices as feminine, mas-

FIGURE 2. Mucosa of anterior half of both membranous vocal folds was de-epithelialized.

FIGURE 3. De-epithelialized portion of both vocal folds was brought together with three sutures.

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FIGURE 4. Preoperative view of glottis of a female with constitutional androphonia.

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FIGURE 5. Postoperative view of glottis of the patient in Figure 4 after anterior glottic web formation.

culine, or neither. Medical school is 6 years in our country; sixth year comprises internship. Minimum follow-up was 1 year and mean follow-up was 30 months. For statistical comparison of results, the significance was taken as P < 0.05. For comparisons of preoperative and postoperative results of scale variables, Student t test for paired samples was used. Normal distribution of scale variables was checked with Shapiro-Wilk test. RESULTS Because anterior two-thirds of glottis is dedicated to phonation and posterior one third is dedicated to breathing, anterior glottic web formation comprising one-third to one-half of membranous vocal folds is not expected to cause breathing problems. Because we injected botulinum toxin A to adductor muscle (thyroarytenoid), abductor action of posterior cricoarytenoid muscle will be unopposed and patients’ glottis will remain in abduction; therefore, airway obstruction is unlikely. None of the patients reported dyspnea on exertion after anterior glottic web formation. Preoperative and postoperative pictures of endoscopies of two patients were provided (Figures 4–7). A comparison of pre- and postoperative VHI-30 results is shown in Table 1. The mean total VHI-30 score decreased from a preoperative value of 38 to a postoperative value of 24; this difference was statistically significant (P < 0.001). The mean functional VHI-30 score increased from a preoperative value of 9 to a postoperative value of 11; this difference was statistically significant (P < 0.001). The mean emotional VHI-30 score decreased from a preoperative value of 19 to a postoperative value of 3; this difference was statistically significant (P < 0.001). The mean pre- and postoperative physical VHI-30 scores were not significantly different (P > 0.05). A comparison of pre- and postoperative acoustic analysis results is shown in Table 2. The patients’ pre- and postoperative mean F0 were 152 and 195 Hz, respectively; their speaking F0 were 158 and 200 Hz, respectively; these differences were statistically

FIGURE 6. Preoperative view of glottis of a male with testicular feminization.

FIGURE 7. Postoperative view of glottis of the patient in Figure 6 after anterior glottic web formation.

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TABLE 1. Comparison of Pre- and Postoperative VHI-30 Results (Student t Test for Paired Samples)

VHI-30 Functional VHI-30 Physical VHI-30 Emotional VHI-30 Total

Preoperative

Postoperative

Statistics

9.36 ± 2.73 9.71 ± 2.02 19 ± 4.27 38 ± 5.64

11.11 ± 1.77 9.46 ± 1.77 3.46 ± 1.95 24 ± 2.65

t = 4.11, P < 0.001 t = 0.89, P = 0.38 t = 19.00, P < 0.001 t = 12.62, P < 0.001

Mean ± standard deviation. Abbreviation: Voice Handicap Index

significant (P < 0.001). Their pre- and postoperative mean jitter percent, shimmer percent, and NHR were not significantly different (P > 0.05) (Table 2). Evaluation of postoperative voice by patient’s self-report revealed the following results: 20 patients reported their voices as feminine, 2 reported as masculine, and 5 rated their voices as neither. Patient satisfaction rate was 74% (20 of 27). Medical students rated the randomly played connected speech samples. There were 675 preoperative and 675 postoperative evaluations (27 × 25). Seven preoperative voice samples were rated as neither; 668 were rated as masculine (99% = 668 of 675). Five hundred seventy-four postoperative voice samples were rated as feminine and 101 as neither (85% = 574 of 675). The success rate of web formation was therefore 85%. The dissatisfied seven patients (26%) (five MFTs and two males) had the following postoperative mean F0 levels after web formation: 155 Hz, 170 Hz, 182 Hz, 180 Hz, 192 Hz, 170 Hz, and 174 Hz. The mean F0 and mean speaking F0 of these seven patients were 175 Hz. and 180 Hz., respectively; the mean F0 and mean speaking F0 of the other 20 patients were 202 Hz. and 207 Hz., respectively; these differences were both statistically significant (Student t test for independent samples, t = 3.82, t = 4.02, P < 0.001, respectively). They did not have any peculiar finding in their vocal tract; just that their postoperative F0 was not good enough. Among these seven patients, two had suture breakdown as a complication of surgery (7% = 2 of 27); they were revised and laser reduction glottoplasty was performed additionally. All were offered laser reduction glottoplasty as a secondary procedure for voice feminization and they were subsequently operated on. After laser reduction glottoplasty, their postoperative mean F0 levels were all above 200 Hz.

DISCUSSION Fundamental frequency (F0) of voice depends on mass, tension, length, stiffness of vocal folds, and subglottal pressure. As mass and length of vocal folds decrease, F0 increases. As tension and stiffness of vocal folds increase, F0 increases. Subglottal pressure has less effect on F0 than the other factors mentioned; as subglottal pressure increases, F0 decreases. Fifty to sixty percent of voice femininity is supplied by F0 and pitch. The rest is determined by vowel formant frequencies (especially F1), voice quality, resonators, and listener ratings.11 The operations that will be discussed all target the larynx, which is the voice box. They never aim for the resonators, which are the pharynx and mouth. Only voice therapy can modify resonators to attain a more feminine voice. It is a sound practice to advice postoperative voice therapy after voice feminizing operations on whether a patient can or is willing to attend voice therapy sessions. Voice is an important aspect of voice identity. MFTs are bothered by their masculine-sounding voice. They seek medical help because of this. Voice therapy can be efficient in feminizing voice; however, voice therapy alone is usually not enough to obtain feminine voice and male voice reappears in situations like yawning, coughing, sneezing, and laughing. Therefore, surgical therapy is often required to attain continuous feminine voice. The most commonly used surgical method to raise the pitch of voice has been increasing vocal fold tension by cricothyroid approximation described by Isshiki et al.1 However, pitch increment is limited and not long lasting after surgery, with a pitch decline within 6–18 months.5 Subjective satisfaction levels are reported to be between 55% and 78.5%.12,13 Presence of skin incision and accentuation of thyroid notch are other disadvantages

TABLE 2. Comparison of Pre- and Postoperative Acoustic Analysis Results (Student t Test for Paired Samples) Preoperative

Postoperative

Statistics

152 ± 12 158 ± 11 0.6 ± 0.1 1.98 ± 0.2 0.07 ± 0.01

195 ± 14 200 ± 15 0.7 ± 0.2 2.1 ± 0.3 0.08 ± 0.01

t = 5.2, P < 0.001 t = 5.6, P < 0.001 t = 0.72, P = 0.24 t = 0.55, P = 0.38 t = 0.52, P = 0.41

Mean F0 Speaking F0 Jitter % Shimmer % NHR Mean ± standard deviation. Abbreviation: NHR, noise-to-harmonic ratio.

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of cricothyroid approximation. Very high tension on the cricoid and thyroid cartilages may damage these cartilages.5 This operation carries no risk of damage to vocal folds and voice. Thyroid chondroplasty can be performed at the same setting, as requested by some MFT. Anterior commissure advancement has a similar physiological basis of increasing vocal fold tension; it has the same disadvantages as cricothyroid approximation.2,3 However, this operation was primarily defined for bowed vocal folds, and not for MFT and other forms of androphonia. Experience is limited to a small case series by the defining surgeons. Kunachak et al14 defined a voice feminizing procedure called thyroid cartilage and vocal fold reduction. It is an external procedure removing the anterior one-third of thyroid cartilage, as well as shortening and tensioning the vocal folds to raise the pitch. This operation makes the male larynx smaller, just like the female larynx. Thomas and Macmillan4 reported their experience about this operation on 76 patients; however, they gave a different name to it: feminization laryngoplasty. Despite being a good voice feminizing procedure, 25 (33%) patients needed revision because of insufficient tension or asymmetric tension on the vocal cords. The authors also added thyrohyoid approximation to this procedure; it consists of removing the superior portion of each thyroid ala (10 mm). Then sutures are placed between the thyroid cartilage and the hyoid bone. This attempts to shorten the resting vertical dimension of the pharynx. Thomas and Macmillan wanted to address resonance tube, which was not addressed in all other voice feminizing procedures. Laser-assisted voice adjustment 6 and laser reduction glottoplasty7 are reducing the bulk of the vocal muscle and ligament and shift the vocal fold mass toward the female size range. Lateral stretching of the medial vocal fold tenses the vibrating portion between the conus elasticus and the sutures, while thinning the cover layer, and changes the shape of the vocal folds from rectangular to triangular, which is more typical of females. They have the advantage of being endoscopic and being performed as an outpatient procedure. However, there is risk of vocal fold scarring and dysphonia. These procedures can be performed after other failed or unsatisfactory voice feminizing operations, such as tensioning or shortening operations. As a difference between the two similar procedures, we can say that sutures are placed between the edges of mucosal cuts in laser reduction glottoplasty; sutures are not utilized in laser-assisted voice adjustment. Anterior glottic web formation relies on decrease in vibrating vocal fold length and vibrating mass of vocal folds to raise the pitch of voice. Pitch increment is permanent after anterior glottic web formation. The web does not impede breathing at rest and during exercise. However, patients frequently complain of decreased intensity of voice during shouting, yelling, and screaming. This is reflected by increased postoperative functional VHI score. Decreased postoperative emotional VHI score shows satisfied and happy patients with a more feminine voice. Anterior glottic web formation can be performed by both external and endoscopic approaches to shorten the vibrating length of the vocal folds to raise pitch. Donald 15 was the first surgeon to define external anterior glottic web formation. The normal male

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adult vocal fold is roughly 1.5 times longer than a female vocal fold, and its cross-sectional mass is also larger. Fundamental frequency varies inversely with vocal fold length if all other parameters are constant, and on this basis, reducing vibrating vocal fold length by one-third should raise the F0 into a female range. Anderson8 thinks that this is not the case in transgendered individuals, and shortening the vibrating vocal fold length by one-third may be insufficient to accomplish a “female” voice given the phenotypic male vocal tract and vocal fold mass. She prefers 40%–50% shortening of membranous vocal fold, just as we do 50%. Remacle et al16 indicated that VHI did not improve after anterior glottic web formation postoperatively, probably because it was not sensitive enough. We do not agree with them, because VHI is sensitive to patients’ voice complaints. Our study found significant decrease in total and emotional VHI scores and a significant increase in functional VHI scores postoperatively. Decreased emotional postoperative VHI score indicated overall well-being of the patient, as they were happy because of being recognized more feminine in the society. Increased postoperative functional VHI score reflected decreased postoperative voice intensity or increased vocal effort required to phonate postoperatively because higher subglottic pressure requirement.16 However, this higher subglottic pressure requirement was not reflected in the patients’ VHI scores. Subglottic pressure is augmented because of the more important work to perform after reduction of the surface of the glottic aperture; however, the vocal effort tends to decrease with time. Remacle et al16 indicate that as most of the patients are young and are not vocal performers, they are not bothered by the temporary rise of vocal effort and the decrease in vocal range. It is our experience that most patients are bothered by the rise in vocal effort and decrease in vocal range. Furthermore, the rise in vocal effort and decrease in vocal range is not temporary; they are permanent. Gross,5 in his series of 10 MFT, reported a reduction in loudness over all frequencies after anterior commissure web formation. However, he was able to restore preoperative loudness levels through voice therapy, but he did not report the details of how he performed this. Patients are seriously bothered by this rise in vocal effort and decrease in vocal range, and are unhappy about surgical result, as reflected in functional VHI scores. Mastronikolis et al17 presented their series of anterior commissure web formation on 31 MFT. They performed CO2 laser de-epithelialization of the anterior commissure along with the anterior third of the two vocal folds, then sutured two vocal folds with two 3/0 absorbable threads, and next applied fibrin sealant to strengthen the stitches. The mean F0 increased from preoperative 136 Hz to postoperative 206 Hz. Three (10%) of their patients presented with suture breakdown and needed revision web formation surgery. We had two (7%) postoperative suture breakdowns and had to revise the cases. Their total VHI did not change significantly; they did not report physical, functional, and emotional VHI scores. Our study found significant decrease in total and emotional VHI scores and a significant increase in functional VHI score postoperatively. There is no mention about the unhappy patient population in their paper. Our cases included

762 seven (26%) unhappy patients who needed additional surgery in the form of laser reduction glottoplasty. We performed deepithelialization with scissors instead of laser. We utilized three or four 5/0 sutures and never used fibrin sealant. We passed a single suture thread through both vocal folds and tied the suture infraglottically, instead of passing two suture threads through each vocal fold and tying them both supra- and infraglottically. To prevent postoperative suture breakdown and attain involuntary voice rest, we injected 2.5 units of botulinum toxin to both vocalis muscles intraoperatively in addition to 7-day complete postoperative voice rest advice. Mastronikolis et al concluded that anterior commissure web formation was an effective technique to feminize the voice in MFTs; furthermore, their results were better in MFTs younger than 40 years of age. Our modifications in the surgical technique of web formation are based on the technique of Dr. Remacle.16,17 Dr. Remacle uses one 3/0 suture for each vocal fold, that is, two sutures for both vocal folds, and ties two sutures below and above vocal folds. We use one 5/0 suture through both vocal folds and tie it below the vocal folds. Dr. Remacle uses two sutures for each case; we used three or four sutures for each patient. After suturing, Dr. Remacle applies fibrin glue to sutured vocal folds as a secondary sealant; we did not use glue after suturing. We injected botulinum toxin to both vocalis muscles to put vocal folds at rest postoperatively to prevent sutures from tearing through vocal folds. Dr. Remacle does not use botulinum toxin. Instead, he advised a 10-day postoperative voice rest. Meanwhile, Geneid et al18 and Casado et al19 used a 15-day postoperative voice rest. It is our experience that even a 7-day voice rest is too long. The practical use of a 15-day voice rest is impossible. Most probably, patients are using their voice and doctors are not aware of it. Therefore, botulinum toxin A injection to both vocal folds is a sound practice after glottic web formation, as it provides involuntary voice rest for a longer time to prevent sutures from cutting through vocal folds. Kim20 published the results of 362 patients with anterior glottic web formation. This is the largest series so far. However, he called his operation vocal fold shortening and retro-displacement of anterior commissure. He thought it was different from anterior glottic web formation. As a difference from the previous web formation techniques, subglottic tissue, including the lamina propria and submucosal glands extending to the cricothyroid membrane portion, was completely removed. To prevent forming only an anterior glottic web, the first suture was placed on the lateral thyroarytenoid muscle, including the low subglottic portion, and the second suture was placed on the vocalis muscle, not including the subglottic portion, which contributes mainly to highpitched sound. Two different levels of sutures formed a funnel shape, and the anterior commissure was relocated to enhance continuous smooth glottic air flow, which is important for a clear voice. He indicated that the anterior one-third of the vocal fold subglottic tissue including the submucosal glands was removed to modify the tactile feedback system. Phonatory feedback system was modified to redirect airflow toward a new glottis to produce a clear voice. We believe that his assumptions are not based on evidence.

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CONCLUSION Anterior commissure web formation is a successful surgical option for voice feminization. However, additional surgery may be necessary for patient satisfaction. A voice surgeon needs to have multiple surgical options for voice feminization in his armamentarium, because many, but not all, patients are not satisfied with the postoperative voice result and ask for a more feminine voice. APPENDIX SUPPLEMENTARY DATA Supplementary data related to this article can be found online at doi:10.1016/j.jvoice.2017.03.006. REFERENCES 1. Isshiki N, Morita H, Okamura H, et al. Thyroplasty as a new phonosurgical technique. Acta Otolaryngol. 1974;78:451–457. 2. LeJeune FE, Guice CE, Samuels PM. Early experiences with vocal ligament tightening. Ann Otol Rhinol Laryngol. 1983;92:475–477. 3. Tucker HM. Anterior laryngoplasty for adjustment of vocal fold tension. Ann Otol Rhinol Laryngol. 1985;94:547–549. 4. Thomas JP, Macmillan C. Feminization laryngoplasty: assessment of surgical pitch elevation. Eur Arch Otorhinolaryngol. 2013;270:2695–2700. 5. Gross M. Pitch-raising surgery in male-to-female transsexuals. J Voice. 1999;13:246–250. 6. Orloff LA, Mann AP, Damrose JF, et al. Laser-assisted voice adjustment (LAVA) in transsexuals. Laryngoscope. 2006;116:655–660. 7. Koçak I, Akpınar ME, Çakır ZA, et al. Laser reduction glottoplasty for managing androphonia after failed cricothyroid approximation surgery. J Voice. 2010;24:758–764. 8. Anderson JA. Pitch elevation in transgendered patients: anterior glottic web formation assisted by temporary injection augmentation. J Voice. 2014;28:816–821. 9. Yılmaz T, Sözen T. Microsuture after benign vocal fold lesion removal: a randomized trial. Am J Otolaryngol. 2012;33:702–707. 10. Yılmaz T. Sulcus vocalis: excision, primary suture and medialization laryngoplasty: personal experience with 44 cases. Eur Arch Otorhinolaryngol. 2012;269:2381–2389. 11. Hardy TL, Boliek CA, Wells K, et al. Pretreatment acoustic predictors of gender, femininity, and naturalness ratings in individuals with male-to-female gender identity. Am J Speech Lang Pathol. 2016;25:125–137. 12. Wagner I, Fugain C, Monneron-Girard L, et al. Pitch-raising surgery in fourteen male-to-female transsexuals. Laryngoscope. 2003;113:1157–1165. 13. Matai V, Cheesman AD, Clarke PM. Cricothyroid approximation and thyroid chondroplasty: a patient survey. Otolaryngol Head Neck Surg. 2003;128:841–847. 14. Kunachak S, Prakunhungsit S, Sujjalak K. Thyroid cartilage and vocal fold reduction: a new phonosurgical method for male-to-female transsexuals. Ann Otol Rhinol Laryngol. 2000;109:1082–1086. 15. Donald PJ. Voice change surgery in the transsexual. Head Neck Surg. 1982;4:433–437. 16. Remacle M, Matar N, Morsomme D, et al. Glottoplasty for male-to-female transsexualism: voice results. J Voice. 2011;25:120–123. 17. Mastronikolis NS, Remacle M, Biagini M, et al. Wendler glottoplasty: an effective pitch raising surgery in male-to-female transsexuals. J Voice. 2013;27:516–522. 18. Geneid A, Rihkanen H, Kinnari TJ. Long-term outcome of endoscopic shortening and stiffening of the vocal folds to raise the pitch. Eur Arch Otorhinolaryngol. 2015;272:3751–3756. 19. Casado JC, O’Connor C, Angulo MS, et al. Wendler glottoplasty and voice-therapy in male-to-female transsexuals: results in pre and post-surgery assessment. Acta Otorrinolaringol Esp. 2016;67:83–92. 20. Kim HT. A new conceptual approach for voice feminization: 12 years of experience. Laryngoscope. 2016;doi:10.1002/lary.26127. In press.