Anterior Glottic Web Research Articles

Comparative Study between Endoscopic Surgical Excision of Anterior Glottic Web with or without Keel Placement

Abstract Background A focal narrowing of the airway caused by fibrotic tissue at the level of the true vocal folds is known as anterior glottic web. Congenital anterior glottic webs are less common than acquired anterior glottic webs. Endotracheal intubation, laryngeal trauma or surgery close to the anterior commissure, radiotherapy, and, in rare cases, inflammatory processes can cause them at any age. Objective To decide the need for endoscopic keel placement for management of anterior glottic web, prevention of vocal cord adhesions and to reduce the recurrence. Patients and Methods This study was systematic review and meta-analysis study included research articles with the following criteria; retrospective, prospective, case series, case report studies, published in English language, in the last 25 years, only studies on humans, studies on congenital and acquired anterior glottic web, studies with endoscopic keel placement, and studies without keel placement. Results The main findings of the current study was that; among keel used studies, the recurrence proportion was 13.5% with 95% Confidence interval (5.5%-24.2%), the proportion of granulation from pooled studies was found in 3.44% with 95% Confidence interval (1.16%-7.5%)and regarding voice improvement in this meta-analysis high significant improvement (94.2%) with 95% Confidence interval (85.8%-99%) was reported; Recurrence among the 3 studies did not use keel was 30.6% with 95% Confidence interval (7%-61. 8%). However, the voice improvement was reported among 97.4% with 95% Confidence interval (91.5 %-99.9%) Data Sources Medline databases (PubMed, Medscape, ScienceDirect. EMF-Portal) and all materials available in the Internet till 2019. Conclusion The optimal treatment of acquired anterior glottic web remains controversial; Placement of a keel has low recurrent rate and good voice improvement but had several disadvantages such as the need for two separate operations under general anaesthesia, prolonged recovery, and the risk of infection and granuloma formation. However other techniques as the mucosal flap technique had better voice improvement without granulation formation with high success rates.

A Modified Approach for Preventing Anterior Glottic Web Formation Using Mitomycin C in Bilateral Vocal Fold Lesions.

Objectives: Laryngeal keel insertion, mucosal suture, application of mitomycin-C (MMC), and staged operations are approaches to prevent the anterior glottic web, but there are limitations. Our study suggests a modified approach to prevent the formation of an anterior glottic web. Methods: This retrospective single-institution tertiary center study (N = 23) involved the simultaneous removal of bilateral vocal fold lesions with topical MMC application. If exudate was identified after 4 to 6 weeks, second laryngomicroscopic surgery (LMS) was performed to remove it with topical MMC application. Extent of anterior glottic web was measured as a percentage of the total length of the membranous vocal fold. Results: After the initial surgery, 18 patients recovered without anterior web or fibrin exudate. Thick exudate was observed in 5 patients. After the second LMS, all patients showed improvement and did not develop anterior web. Conclusion: This modified method has been developed to prevent the anterior glottic web without complications.

Laryngeal Cancer Presenting as an Anterior Glottic Web.

Laryngeal Cancer Presenting as an Anterior Glottic Web.

Assessing the concern for airway complications introduced by Wendler's glottoplasty.

Wendler's glottoplasty (WG) is a pitch-elevating surgery performed by laryngologists providing gender-affirming care. The surgery creates an anterior glottic web that could theoretically cause airway concerns, either perioperatively or at the time of future procedures; such concerns are not well-described in the literature. We seek to assess surgeon opinions on airway concerns regarding WG. A survey of laryngologists assessing opinions on airway considerations in glottoplasty. A total of 19 physicians responded, representing approximately 193 surgeries. 52.6% performed glottoplasty and the remainder responded based on experience with anterior glottic webs. Two perioperative airway complications were reported, both mild stridor that did not prevent same-day discharge. No long-term sequela was reported. All surveyed laryngologists endorsed an altered general anesthetic approach for future procedures, with 73.7% advocating for use of a smaller endotracheal tube. 72.2% did not have "major concerns" about future intubations, and only 5.3% thought the immediate risk of airway compromise was a "real concern." 91.9% counsel their patients routinely but briefly on airway concerns. Open-ended comments conveyed themes of concern for post-operative disruption of the web more than of airway compromise. Because glottoplasty is performed in the anterior glottis and does not significantly impact airway patency, the risk of serious airway complications appears to be minimal. Laryngologists believe future intubations require a modified approach with a smaller tube, partly due to concern for glottic web trauma. Based on this pilot study, the topic deserves greater work to standardize care and anesthetic alterations for patients with WG. 5.

An Acquired Anterior Glottic Web Model by Heat Injury with a Laryngoscopic Approach in a Rabbit.

Acquired anterior glottic webs (AGW) can lead to abnormally elevated phonatory pitch, dysphonia, and airway obstruction requiring urgent intervention. In this study, we construct a novel AGW rabbit model using heat injury by a laryngoscopic way. A primary study was conducted to identify the injury depth in rabbits' vocal folds (VFs) by graded heat energy, and the heat energy for the incurrence of epithelial layer, lamina propria, and muscular layer (ML) injury was 25, 30 and 35 W, respectively. Then, four different models were designed based on the depth and degree of the injury to determine the optimal procedure for AGW formation. Morphological features, vibratory capacity, and histopathologic features of the AGW were correspondingly evaluated. The procedure for conferring the heat injury to the depth of ML and the extent of anterior commissure and middle part of bilateral VFs showed the highest success rate of AGW formation (95%, 19/20). For its low cost, effectiveness, and stability for AGW formation, the heat injury rabbit model with a laryngoscopic approach may provide a new platform for testing novel anti-adhesion materials and bioengineered therapies. Impact Statement Tissue engineering based on biomaterials has been a very hot research field and may be introduced to prevent the acquired anterior glottic web (AGW) formation. However, lacking a widely recognized animal model for AGW has limited the trial of anti-adhesion materials in the larynx. In this study, we have developed a novel rabbit model for AGW formation by conferring a heat injury under a laryngoscope; this model is cheap, effective, and stable for the anti-adhesion materials and bioengineered therapies. Thus, this research would arouse crucial interest and be widely employed.

Gender Affirming Laryngeal and Voice Surgery.

Gender affirmation laryngeal and voice surgeries are components of “voice-lift” or cosmetic voice surgeries. Feminization surgery can modify vocal folds (fundamental frequency [Fo]) and vocal tract (resonance frequency). For increased pitch, vocal folds should be shorter, thinner, and tighter. Cricothyroid approximation (CTA) surgery increases tension of the vocal folds. Endoscopic procedures for pitch raising are done by shortening the length and reducing mass of vocal folds. This shortening is achieved by surgically creating anterior glottic web. Comparing the results of various open and endoscopic surgical techniques, fundamental frequency (Fo) is raised maximally and remains stable after GL as compared with CTA.

Anterior Glottic Web Secondary to Bioenzyme Toxicity.

Anterior Glottic Web Secondary to Bioenzyme Toxicity.

Complications and outcomes following open laryngotracheal reconstruction: A 15 year experience at an Australian paediatric tertiary referral centre

ObjectiveTo report on our experience with open pediatric laryngotracheal reconstruction (LTR) with cartilage interposition grafts over the past 15 years and document setbacks and factors that affect postoperative outcomes. MethodA retrospective chart review was performed on all pediatric patients who underwent single and double-stage LTR at The Children’s Hospital in Westmead between August 2004 and July 2019. The outcomes measured include the overall decannulation rate, rates of postoperative complications, need for subsequent procedures and postoperative functional results (dyspnea, stridor, voice impairment). ResultsBetween August 2004 and July 2019, a total of 51 open LTRs were performed on 46 patients, with mean age 3.9 years (range 1 month to 12.1 years), including 11 revision operations (11.8%). The most common indication for surgery was subglottic stenosis, followed by bilateral vocal cord motion impairment followed by anterior glottic web. 13 cases (25.5%) were complicated by ventilator associated pneumonia in the postoperative period and 11 patients (21.6%) experienced wound complications ranging from localised wound abscess to wound dehiscence and graft failure. Patients with viral infections had an increased risk of wound dehiscence and graft failure (OR 1.8, 95% CI 1.01 – 3.23). Patients with a greater decrease in albumin in the postoperative period were more likely to have wound complications (OR 1.8; 95% CI 1.17 -2.83). Ten patients failed extubation and required a subsequent tracheostomy. Severity of stenosis, age at time of surgery, history of prematurity and revision LTR were not predictors for need for reintubation and/or tracheostomy after surgery. 23 cases (45.1%) underwent subsequent endoscopic procedures such a balloon dilatation to manage restenosis following LTR. Though 45.7% had a very good outcome, a significant group of 21% had ongoing voice issues. ConclusionGood outcomes were achieved following open LTR for pediatric laryngotracheal stenosis despite postoperative complications. At final follow up, 33 patients (71.7%) had good exercise tolerance with no or mild stridor. Forty-one of the forty-six patients (89.1%) were successfully decannulated.

Laser Reduction Glottoplasty for Voice Feminization: Experience on 28 Patients.

Laser reduction glottoplasty is a relatively new surgical procedure for voice feminization on transgender women. This study aims to determine long-term voice results of glottoplasty on transwomen. Nonrandomized, retrospective, cohort. Tertiary referral center. Endoscopic laser reduction glottoplasty was performed on 28 transwomen. Voice Handicap Index (VHI-30), Transsexual Voice Questionnaire (TVQ), acoustic analysis with /a/ for F0, jitter, shimmer, noise to harmonic ratio and acoustic analysis for speaking F0 were measured before and after surgery. Patients self-evaluated their postoperative voices and medical students and 2 voice experts scored patients' pre- and postsurgery voice samples as masculine, feminine or neither. Mean total VHI and TVQ scores improved significantly postoperatively (P < .001). Pre- and postsurgery mean F0 were 132 and 198 Hz and mean speaking F0 were 123 and 194 Hz, respectively; these variations were found statistically significant (P < .001). Postoperative mean jitter, shimmer and NHR increased significantly compared to preoperative values (P < .05). Nine patients (32%) were not happy with their postsurgery voice result and were offered anterior glottic web formation as secondary procedure. MFT women's self-ratings of their postsurgery voices showed 3 masculine, 19 feminine and 6 neither outcomes, leading to patient gratification score of 68%. Medical students evaluated 79% of postsurgery voice specimens as feminine. Voice experts evaluated 75% of postsurgery voice specimens as feminine. Laser reduction glottoplasty is an accomplished and satisfying operation for feminizing voice of transwomen. Its voice outcome appears to be durable for 5 years. However, secondary operation may be needed to further gratify transwomen.

Surgical Management of Anterior Glottic Webs.

Congenital webs are rare and represent <5% of all congenital laryngeal anomalies. They are usually a partial laryngeal atresia rather than a true web, and present as a thick and fibrotic web with subglottic extension and associated subglottic stenosis. All patients with a congenital anterior glottic web should be evaluated for chromosome 22q11.2 deletion syndrome. Management strategies are mainly based on the severity of airway obstruction and the anatomical extension of the webs. Simple division of the web endoscopically may be adequate for rare thin webs, however, an open approach is usually warranted for thick glottic webs regardless of Cohen grades. Open repair can be either with keel placement or reconstruction of the anterior commissure.

Surgical management of acquired anterior glottic web: a systematic review.

Acquired anterior glottic web poses a significant challenge to laryngologists given its propensity to recur following treatment, and there are a wide variety of described techniques. A systematic review of the medical literature was undertaken in order to identify all articles pertaining to the management of acquired anterior glottic web. Thirteen studies meeting the inclusion criteria were identified and analysed. All were retrospective series, with varying surgical techniques and outcome measures. Only two studies reported on the use of topical mitomycin C. Mucosal graft techniques and keel placement appear to improve success rates, but both carry risks and disadvantages. Based on the available evidence, the use of topical agents such as mitomycin C cannot be recommended in the management of acquired anterior glottic web.

Single and double mucosal microflap CO2 laser “sliding” technique in the management of iatrogenic glottic web: anatomical and functional results

An anterior glottic web consists of the formation of a bridge of scar tissue covered by epithelium between the anterior free edges of the true vocal cords and represents one of the most common complications of laryngeal endoscopic surgery for tumors involving the anterior commissure. Endoscopic surgery is the therapy of choice, but simple section of the web is burdened by a high recurrence rate. Topical application of mitomycin C, intracordal stents, and the use of mucosal microflaps have been proposed to improve outcomes. We report our experience with the use of single and double mucosal microflaps (sliding technique) during the management of iatrogenic anterior glottic web (IAGW). From November 2010 to December 2018, 30 patients (29 males, 1 female, mean age 65years, range 47-87years) were observed for IAGW, and 11 of these patients (36.7%) required surgical treatment. The Voice Handicap Index (VHI) and the GRBAS were used for the perceptive evaluation of pre- and post-operative voice quality. A reduction of the web length was observed in all cases, and we did not observe any residual web at the mid-third of the glottis. The mean post-operative VHI score decreased from 45 to 24, and the mean post-operative GRBAS values were reduced from 2.8, 2.4, 2.3, 2.1, and 1.1 to 1.9, 1.4, 1.3, 1.1, and 0, respectively. The microflap technique represents an effective and reproducible one-step procedure that, in expert hands, allows to obtain good anatomical and functional results in a high percentage of cases.

An ex vivo porcine model of the anterior glottoplasty for voice feminization surgery.

Perceived gender identity is correctly assigned when a combination of physical and vocal attributes become congruent. Several voice feminization procedures have gained popularity, but current evidence of their impact on vocal feminization is limited to case series. This study establishes an ex vivo porcine phonatory model to evaluate the ideal extent of anterior glottic web formation in relation to frequency elevation and airway patency. Six fresh porcine larynges were obtained and fitted with arytenoid adduction sutures. Compressed air was passed through the larynges, and the vocal folds were adducted to induce phonation. Vocal fold length, posterior glottic width, fundamental frequency, and sound pressure intensity were measured as the vocal folds were progressively shortened as per the anterior glottic web surgical technique. The average fundamental frequency prior to web formation was 109.7 Hz. The maximum frequency achieved after web formation was 403.7 Hz, and the web proportions varied from 11.8% to 61.0% of the length of the membranous vocal folds. The glottic cross-sectional area showed an expected inverse linear relationship to the length of the glottic web. Creation of an anterior glottic web caused consistent elevation of pitch, but there was a gradual plateau of effect with increased length of the web. The ex vivo porcine larynx is demonstrated as an effective, available, and low-cost model for further study of vocal pitch elevation surgical techniques. We demonstrate that in addition to progressively reducing the cross-sectional area of the airway, additional benefit from increased web length is limited. NA Laryngoscope, 130:E206-E212, 2020.

Carcinoma presenting as idiopathic anterior glottic webs: A case series

An anterior glottic web is an abnormal fusion of the anterior aspect of the membranous vocal folds. Noncongenital glottic webs are usually iatrogenic from intubation or laryngeal surgery. We present six adult patients whose initial in-office diagnoses were consistent with "idiopathic" benign anterior glottic webs as determined by three laryngologists (a.m.k., j.m.b., m.j.p.). Further evaluation revealed the diagnoses of laryngeal squamous cell carcinoma in all cases. The high risk of malignancy in cases of idiopathic anterior glottic web necessitates biopsy for tissue diagnosis of all such lesions. Laryngoscope, 129:2118-2120, 2019.

Fundamental Frequency in Excised Human Larynges after Anterior Glottic Web Formation of Various Extents.

To determine the effect of vocal fold anterior web formation on fundamental frequency with a cadaveric excised larynx model. Experimental study with excised human larynges. Academic tertiary care hospital. Sixteen freshly excised human larynges were evaluated with high-speed videoendoscopy and digital kymography during artificially produced vibration. Each larynx was assessed in 4 conditions: preoperative controls and after 25%, 33%, and 50% decreases in the vibratory portion of the vocal folds. The following parameters were evaluated: fundamental frequency, periodicity, vocal fold vibration amplitude, phase symmetry, and glottic closure. The mean fundamental frequencies were 208.87, 250.20, 292.37, and 342.67 Hz for preoperative controls and 25%, 33%, and 50% reductions in vibratory length of the vocal folds, respectively. Fundamental frequency increased with each increase in anterior glottic web extent, and the difference among the groups was statistically significant in absolute values in hertz and in semitone elevation. The mathematical models for estimating postoperative fundamental frequency had a statistically significant coefficient. The vibration of the vocal folds remained periodic in all larynges before and after the procedures. There was a significant and progressive increase in the fundamental frequency with each enlargement of anterior glottic web. Based on the control frequency, mathematical models could estimate the value of the fundamental frequency after the procedure.

Airway Anomalies in Patients With 22q11.2 Deletion Syndrome: A 5-Year Review.

To characterize the frequency of airway anomalies in patients with 22q11.2 deletion syndrome (22q11DS). Retrospective review of patients with 22q11DS who had undergone microlaryngoscopy/bronchoscopy (MLB) for aerodigestive symptoms at a tertiary care children's hospital from 2011 to 2016. Thirty patients underwent an MLB due to the following indications: aspiration (11), stridor (10), chronic respiratory failure due to ventilator dependence (8), and difficult intubation (1). Median age at MLB was 6.5 months (range, 0.25-32 months). Forty airway anomalies were identified in 20 (66%) patients. Laryngomalacia (10), tracheomalacia (8), and bronchomalcia (8) were the most common intraoperative findings, followed by laryngeal cleft (5), anterior glottic web (5), subglottic stenosis (3), and subglottic cysts (1). Synchronous airway anomalies were common and identified in 11 (55%) of the patients who had identified anomalies on MLB. Nineteen of the 20 patients required operative intervention due to the anomalies identified. Structural airway abnormalities are common in children with 22q11DS undergoing MLB, and synchronous anomalies can frequently exist. Providers caring for children with 22q11DS should be vigilant about airway evaluation when aerodigestive symptoms are present.

Web thickness determines the therapeutic effect of endoscopic keel placement on anterior glottic web.

This work is a retrospective analysis to investigate the critical risk factor for the therapeutic effect of endoscopic keel placement on anterior glottic web. Altogether, 36 patients with anterior glottic web undergoing endoscopic lysis and silicone keel placement were enrolled. Their voice qualities were evaluated using the voice handicap index-10 (VHI-10) questionnaire, and improved significantly 3months after surgery (21.53±3.89 vs 9.81±6.68, P<0.0001). However, 10 (27.8%) cases had web recurrence during the at least 1-year follow-up. Therefore, patients were classified according to the Cohen classification or web thickness, and the recurrence rates were compared. The distribution of recurrence rates for Cohen type 1~4 were 28.6, 16.7, 33.3, and 40%, respectively. The difference was not statistically significant (P=0.461). When classified by web thickness, only 2 of 27 (7.41%) thin type cases relapsed whereas 8 of 9 (88.9%) cases in the thick group reformed webs (P<0.001). These results suggest that the therapeutic outcome of endoscopic keel placement mostly depends on the web thickness rather than the Cohen grades. Endoscopic lysis and keel placement is only effective for cases with thin glottic webs. Patients with thick webs should be treated by other means.

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

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. This is a nonrandomized prospective cohort study. University hospital. 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. 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%. Anterior commissure web formation is a successful surgical option for voice feminization. However, additional surgery may be necessary for patient satisfaction.

An Excised Canine Model of Anterior Glottic Web and Its Acoustic, Aerodynamic, and High-speed Measurements

This study aims to build an excised anterior glottic web (AGW) model and study the basic voice-related mechanisms of the AGW through investigating the acoustic, aerodynamic, and vibratory properties. Overall, four conditions were tested for each of the eight canine larynges used. At baseline, 10%, 20%, and 33% occlusion (as determined by the placement of the suture), acoustic, aerodynamic, and high-speed video data were collected while each larynx was phonated in a soundproof booth. The phonation threshold pressure (PTP) and the phonation threshold flow significantly increased as percent occlusion increased (P < 0.001). There were significant increases in jitter % and shimmer % from baseline group to AGW model groups at PTP, 1.25 PTP, and 1.5 PTP (P = 0.039, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P = 0.001, respectively). The fundamental frequency significantly increased as percent occlusion increased at all given pressures (P < 0.001). Correlation dimension (D2) was significantly higher in the AGW model groups than in the baseline group at PTP, 1.25 PTP, and 1.5 PTP (P = 0.002, P < 0.001, P = 0.01, respectively). High-speed videos revealed that, the left phase shift in the AGW model groups compared with the baseline at 1.25 PTP was significant (P = 0.027) and right phase shift at 1.5 PTP (P < 0.001). We presented an anatomically similar model of a type 1 AGW and confirmed its validity through aerodynamic, acoustic, and high-speed video analysis in our study. We observed and investigated the glottic web movement, which may be a new explanation for the pathologic voice-related mechanism of AGW.

Prevention of anterior glottis web with hyaluronic acid derivatives in rabbit model.

Validating an antiadhesive strategy to prevent anterior glottic web (AGW) development. Prospective animal study in rabbits. Fifteen New Zealand white rabbits were randomly divided into three equal groups (five rabbits each), applying either HyFence (HF: 0.1 g/vocal fold), an antiadhesive test agent; mitomycin-C (MMC: 1 mg/ml, 4 min) as reference therapy; or saline (control group) to AGWs induced by laryngofissure technique (previously reported by us). At week 8, the extent of AGW was measured to assess preventive effects of HF and MMC, and laryngeal specimens were sampled for high-speed recording and histologic analysis. AGW induction was successful in all five (100%) control rabbits, each demonstrating fibroconnective tissue and collagen fibers at anterior commissure, with AGW ratio averaging 0.57 ± 0.052. An AGW was seen in 100% of the rabbits survived in the MMC group (n = 2) with the 60% (n = 3) of the MMC rabbits expired due to postprocedure infections. The average AGW ratio was 0.28 ± 0.070 in the MMC group. AGW formation rate was 50% in HF group with one rabbit expired from infection. Mean AGW ratio was lowest in the HF group (0.23 ± 0.10; P = 0.013). Microscopically, AGW induction sites in HF-treated rabbits displayed significantly fewer collagen fibers (P = 0.009) by comparison. This is the first reported use of a cross-linked hyaluronic acid gel that may prevent AGW formation. N/A. Laryngoscope, 126:2320-2324, 2016.