[Application of acellular dermal matrix in prevention of laryngeal stenosis in glottic carcinoma].

Objective:To investigate the effect of acellular dermal matrix in preventing laryngeal stenosis in glottic carcinoma patients. Methods:Fifty-five patients with glottic carcinoma（T2, T3） from February 2018 to December 2022 were divided into experimental group（28 cases） and control group（27 cases） according to their wishes. Acellular dermal matrix was placed in the operation cavity in the experimental group after laryngofission, while control group 12 cases were sutured by pulling the upper and lower edges, 15 cases were repaired with sternohyoid muscle fascia flap. Results:In the experimental group, 1 case had laryngeal stenosis caused by laryngeal mucosa swelling after operation, and extubated successfully after symptomatic treatment. In the control group, 7 cases had laryngeal stenosis after operation, of which 3 cases were caused by granulation tissue hyperplasia in laryngeal cavity, and extubated after symptomatic treatment. 2 cases extubated after operation suffered from progressive dyspnea during radiotherapy, and underwent tracheotomy again, extubation successful after treatment. 2 cases caused by laryngeal mucosa swelling, after symptomatic treatment, one case was successfully extubated, and one case had long-term intubation. The laryngeal stenosis rate of the experimental group was 3.6%（1/28） , which was lower than control group 25.9%（7/27）, and the therapeutic effect of the experimental group was significantly better than control group （χ²=5.526, P=0.019）. Conclusion:Implanting acellular dermal matrix in the operation cavity of glottic carcinoma can reduce the occurrence of laryngeal stenosis and have satisfactory preventive effect on laryngeal stenosis.

Length of the Cricoid and Trachea in Children: Predicting Intubation Depth to Prevent Subglottic Stenosis.

OBJECTIVE: Define the length of the subglottis and trachea in children to predict a safe intubation depth. METHODS: Patients <18 years undergoing rigid bronchoscopy from 2013 to 2020 were included. The carina and inferior borders of the cricoid and true vocal folds were marked on a bronchoscope and distances were measured. Patient age, weight, height, and chest height were recorded. Four styles of cuffed pediatric endotracheal tubes (ETT) were measured and potential positions of each cuff and tip were calculated within each trachea using five depth of intubation scenarios. Multivariate linear regression was performed to identify predictors of subglottic and tracheal length. RESULTS: Measurements were obtained from 210 children (141 male, 69 female), mean (SD) age 3.21 (3.66) years. Patient height was the best predictor of subglottic length (R2 : 0.418): Lengthsg (mm) = 0.058 * height (cm) + 2.8, and tracheal length (R2 : 0.733): Lengtht (mm) = 0.485 * height (cm) + 21.3. None of the depth of intubation scenarios maintained a cuff-free subglottis for all ETT styles investigated. A formula for depth of intubation: Lengthdi (mm) = 0.06 * height (cm) + 8.8 found that no ETT cuffs would be in the subglottis and all tips would be above the carina. CONCLUSION: Current strategies for determining appropriate depth of intubation pose a high risk of subglottic ETT cuff placement. Placing the inferior border of the vocal cords 0.06 * height (cm) + 8.8 from the superior border of the inflated ETT cuff may prevent subglottic cuff placement and endobronchial intubation. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:S1-S10, 2022.

A Randomized Controlled Trial of Dexamethasone as a Prophylactic Treatment for Subglottic Stenosis in a Rabbit Model.

OBJECTIVE: Iatrogenic injury is a common cause of subglottic stenosis (SGS). We investigated the role of pre-injury dexamethasone as a preventive treatment for iatrogenic subglottic stenosis. METHODS: 16 New Zealand White rabbits were used in an IACUC approved study. Subjects were divided into two groups: intramuscular dexamethasone (DEX) at a dose of 2 mg/kg 15 minutes prior to an endoscopic injury to create SGS, and the same injury creation with a preoperative intramuscular saline (SAL) injection. Three independent, blinded raters evaluated endoscopic images to obtain cross sectional area (CSA) airway measurements. Rabbit airways were measured just prior to injury and at one week post-injury. All subjects were provided as-needed postoperative steroids and buprenorphine for symptoms of respiratory distress. Data analysis was performed using Student t-test. Intraclass correlation coefficients were used to assess inter-rater agreement. RESULTS: All subjects survived to the one-week post-injury airway evaluation. There was no difference in airway size between groups prior to injury (P = .28). Subjects in the DEX group demonstrated an average stenosis of 20.3% (95% CI 10.2-30.5) at one week compared to 60.6% (95% CI 40.3-80.9) in the SAL group (P = .01). Subjects in the control group required significantly more doses of postoperative dexamethasone (P = .02). Inter-rater agreement for between raters was excellent (ICC = .88). CONCLUSION: This is the first study to examine the role of pre-injury glucocorticoids in preventing iatrogenic subglottic stenosis. In our model, a single dose of intramuscular dexamethasone given prior to a subglottic injury resulted in a statistically significant reduction in airway stenosis. This research suggests that administering systemic dexamethasone should be considered prior to any procedure that may injure the subglottis, including traumatic intubation, to prevent iatrogenic subglottic stenosis.

Transglottic corticosteroid injection for treatment of soft post-intubation subglottic stenosis: a retrospective analysis of 26 children.

PURPOSE: Surgical treatment is generally recommended for severe subglottic lesions following traumatic endotracheal intubation in children. An alternative approach is early transglottic corticosteroid administration to reduce scar formation and prevent the need for subsequent surgical intervention. This technique has been practiced successfully for several decades at the Children's Hospital of Cologne and the outcomes of 26 subsequent patients reviewed in this analysis. METHODS: All patients who underwent transglottic corticosteroid injection for treatment of post-intubation stridor and dyspnoea between 2012 and 2018 were identified and their records and endoscopy images analysed. Severity of the endoscopic findings was assessed using the Myer-Cotton classification (MCC) and an Expected Need for Surgical Intervention (ENSI) score (1 = inevitable; 2 = very likely necessary; 3 = probably avoidable and 4 = most likely not necessary) was recorded. Treatment was considered successful if the children had a complete resolution of clinical symptoms. RESULTS: A total of 26 patients with a median (range) age of 1.9 (0.02-7.2) years and weight of 9.8 (1.8-25) kg were identified and included into the analysis. Endoscopic images were available for 22 children. All children underwent transglottic corticosteroid injection prior to any potential surgical treatment. A total of 22 patients (85%) improved following transglottic corticosteroid injection including 4 of 5 patients with a MCC = 3 and ENSI = 1 avoiding surgical intervention. None of the patients experienced a deterioration of clinical symptoms or endoscopic findings. CONCLUSION: Transglottic corticosteroid injections as first-line treatment in children with severe post-endotracheal intubation trauma can successfully resolve symptoms and prevent invasive surgery.

Laryngotracheal foreign body: chicken neck bone.

We herein present a case involving a 78-year-old patient who had aspirated a laryngotracheal foreign body 3 days prior to hospital admission. The patient had severe congenital intellectual disability; however, no agitation, suffocation, or death occurred despite almost complete laryngeal obstruction. The laryngotracheal foreign body was removed by tracheotomy and suspended microlaryngoscopy.

Prevención, diagnóstico y manejo de lesiones laringotraqueales agudas y subagudas posintubación en pacientes pediátricos / Prevention, diagnosis and management of acute and subacute laryngotracheal post-intubation lesions in pediatric patients

Las lesiones laringotraqueales asociadas a intubación se deben principalmente a una técnica defectuosa y a daño por presión del tubo endotraqueal sobre la mucosa; además influyen características propias del paciente y de los cuidados de enfermería. Hasta el 40% de los pacientes pediátricos intubados pueden presentar alteraciones laríngeas inmediatas y hasta 30% tienen estridor o disnea posextubación. Si estos síntomas persisten por más de 3 días tendrían indicación de laringotraqueoscopía. Las lesiones más habituales son edema, úlceras y tejido de granulación. El edema puede producir obstrucción respiratoria aguda que puede manejarse con reintubación con tubos más pequeños y aplicación tópica de crema de corticoides con antibióticos. Las úlceras y granulaciones pueden evolucionar hacia secuelas cicatriciales que comprometen la fisiología laringotraqueal; las granulaciones exofíticas deben retirarse endoscópicamente. Aunque la incidencia de estenosis subglótica posintubación ha disminuido en las últimas décadas, situándose entre 2,7%y 4,2%, algunos estudios sugieren un subdiagnóstico debido a lesiones poco sintomáticas al alta. En el período cicatricial activo, estas estenosis pueden dilatarse para evitar llegar a una cirugía abierta. El manejo otorrinolaringológico de estos pacientes en etapas tempranas es fundamental para evitar secuelas cicatriciales irreversibles que requieren de cirugías complejas, con riesgo vital por obstrucción de la vía aérea.

Intubation-associated laryngotracheal injuries are mainly caused by a defective technique and endotracheal tube pressure-induced mucosal damage; patient factors and nursing care are also important. Up to 40% of intubated pediatric patients may show immediate laryngeal alterations and up to 30% have post-extubation stridor or dyspnea. If these symptoms last for over 3 days, laryngotracheoscopy is indicated. Edema, ulcers and granulation tissue are the most usual lesions. Edema can lead to acute airway obstruction, and is managed by reintubation with a smaller tube and topical application of a corticosteroid and antibiotic cream. Ulcers and granulations can lead to scarring that compromise laryngotracheal physiology; exophytic granulations must be removed endoscopically. Although the incidence of post-intubation subglottic stenosis has diminished over the last decades to about2,7% to 4,2%, some studies suggest that there is a subdiagnosis because of oligosymptomatic lesions at the time of discharge. On the active scarring period, dilatation of the stenosis can be used to avoid open surgery. Early otorhinolaryngologic management of these patients is fundamental for avoiding irreversible cicatricial sequels that require complex surgeries, with life risk due to airway obstruction.

[The algorithm for rehabilitation of the patients presenting with laryngeal cancer following open functionally sparing operations].

The objective of the present study was to increase the efficiency of the treatment of the patients presenting with laryngeal cancer by the enhancement of the functional reserve of the preserved portion of the larynx and the prevention of the narrowing of its lumen. Another objective was to develop an algorithm for the rehabilitation of the patients with laryngeal localization of the tumour following open functionally sparing operations that consists of the operative and postoperative stages. During the period from 2006 to 2014, a total of 71 patients underwent functionally sparing operations. 66 of them were operated for laryngeal cancer, 1 for thyroid cancer spreading over trachea and larynx, 3 for papillomatosis. Resection of the larynx in the vertical and horizontal planes was performed in 62 and 9 patients respectively. Vertical plane surgery included the following procedures: fronto-lateral resection of the larynx in 51 patients, extended fronto-lateral resection in 10, and combined resection in 1 patient. It is concluded that the systemic approach to the treatment of the patients with laryngeal cancer and the proposed algorithm for their rehabilitation made it possible to restore the laryngeal function in 68 of the 71 patients (95.8%).

Use of local mitomycin C in enhancing laryngeal healing after laser cordotomy: a prospective controlled study.

BACKGROUND: The purpose of this study was to investigate the role of intraoperative application of mitomycin C in prevention of glottic restenosis after posterior transverse CO2 laser cordotomy (PTLC) for patients with post-thyroidectomy bilateral vocal fold paralysis. METHODS: Twenty-five patients with an impaired airway because of bilateral vocal fold paralysis were treated with PTLC. Patients were divided into groups: the mitomycin C group (13 patients) had PTLC and topical mitomycin C; and the control group (12 patients) had PTLC only. RESULTS: No patients in the mitomycin C group developed glottic granulation or laryngeal scarring, whereas 5 of 12 patients in the control group developed granulation (p = .014) and 2 of 12 patients had laryngeal scarring (p = .28). Ten of 13 patients in the mitomycin C group ended up with mild dyspnea with no limitation to normal everyday activities whereas only a third of the control group achieved this outcome (p = .05). CONCLUSION: The use of topical mitomycin C has been shown to decrease postoperative laryngeal granulation, scarring, restenosis, and the need for revision surgery.

Endoscopic keel placement to treat and prevent anterior glottic webs.

We performed a retrospective chart review to examine and describe our clinical experience of use of the Lichtenberger technique to place silicone elastomer keels after lysis of existing webs or for prevention of webs following anterior commissure surgery in adults. Twenty-two patients were identified for inclusion, ranging in age from 24 to 80 years. For 18 patients with existing glottic webs,the surgical procedure involved laryngoscopy with complete lysis of the anterior glottic web by laser or sharp technique, followed by placement of a square of silicone elastomer that is sutured in place with the Lichtenberger needle holder and left in place for 3 to 5 weeks. The procedure was well tolerated, and successfully corrected the web in all but 2 cases. For 4 patients, the procedure was performed prophylactically at the time of anterior commissure surgery considered high-risk for web formation. The procedure does not require a tracheotomy, and patients can maintain a normal diet and have functional phonation while the keel is in place. This approach to treating anterior glottic webs offers several advantages over traditional open thyrotomy with keel placement and should be considered to treat or prevent anterior glottic webs.

Endotracheal tube: friend or foe? Bacteria, the endotracheal tube, and the impact of colonization and infection.

The microbiology of the endotracheal tube culture plays a role in diagnosing a variety of diseases in the newborn intensive care unit, including subglottic stenosis, bronchopulmonary dysplasia, and ventilator-associated pneumonia. Bacterial production of a biofilm that coats the endotracheal tube acts as a reservoir for infection, prevents eradication, and may play a role in the development of subglottic stenosis. The diagnosis of ventilator-associated pneumonia is limited by the CDC definition as well as currently available diagnostic methods. Biomarkers could aid in differentiating colonization from infection, but are not available to most clinicians. The etiology of ventilator-associated pneumonia is often polymicrobial. Failure to differentiate colonization from infection results in unnecessary prescription of antibiotics, which could contribute to antimicrobial resistance. Measures to prevent ventilator-associated pneumonia have been described, primarily in the adult population.

Cyclooxygenase-2 inhibition for the prevention of subglottic stenosis.

OBJECTIVE: To evaluate the role of targeted cyclooxygenase-2 inhibition in reducing scarring associated with a subglottic airway mucosal injury. DESIGN: Thirty-four New Zealand white rabbits underwent anterior cricothyroidotomy. Subglottic stenosis (SGS) was created by carbon dioxide laser injury. INTERVENTION: Treatment consisted of intraperitoneal injection of celecoxib or vehicle for 4 days. Endoscopies were performed to assess injury and healing. Subglottic mucosal secretions were collected with Gelfoam swabs (Pfizer Inc) before and after injury and at subsequent time points. Animals were humanely killed at 3 or 8 weeks after injury and airways were excised, followed by gross examination and histologic analysis to assess the severity of SGS. Secretions were analyzed for interleukin-1ß, prostaglandin E2 (PGE2), and matrix metalloproteinase-8 by enzyme-linked immunosorbent assays. RESULTS: Endoscopy showed mild to moderate stenosis in the celecoxib group, but mild to severe stenosis in the vehicle group. Histologic assessment confirmed and quantified reduction in stenosis and scarring as well as advanced reepithelialization. In the healing tissue, mucosal thickening (stenosis) was reduced significantly (P = .02) in celecoxib-treated animals compared with those treated with vehicle, at 3 and 8 weeks (decrease in thickness by 32% and 49%, respectively). Collagen density (fibrosis) was also reduced 25% at both 3 and 8 weeks but the difference was not statistically significant (P = .20). Reduced level of PGE2 in the subglottic mucosal secretions was correlated with mucosal thickness at 8 weeks (P = .02). CONCLUSION: Short-duration, anti-inflammatory therapy resulted in reduced stenosis and fibrosis with correlation of PGE2 levels in subglottic mucosal secretions.

Effect of pentoxifylline and 5-fluorouracil/triamcinolone on laryngotracheal stenosis developing as a complication of tracheostomy: study in rats.

We aimed to investigate the prophylactic effect of pentoxifylline (PTX) and 5-fluorouracil (5-FU) on laryngotracheal stenosis in tracheotomised rats by evaluating blood glutathione peroxidase (GPx) and superoxide dismutase activities and by histopathological evaluation of laryngotracheal segment. Randomized prospective single-blind study. Standard vertical tracheotomy was performed on 24 rats. Then, the animals were randomly divided into three groups. Intraperitoneal PTX administered to group A (study group) for 10 days. 5-FU was injected in paratracheal tissues in group B (study group) for 10 days. In group C (control group), intraperitoneal saline was administered for 10 days. After 10 days, tracheal cannules were removed. For biochemical analysis, two blood samples were obtained. Three weeks later, all animals were euthanized and trachea specimens were harvested. Stenosis index and mean wall thickness in PTX group were lower as compared to other groups but the difference was statistically insignificant. Minimum inflammation and fibrosis plus maximum epithelial regeneration were seen in PTX group. In addition, GPx activity was at highest level in PTX group and a statistically significant difference was found between control and PTX groups (P = 0.024) though the difference between remaining groups was statistically insignificant (P = 0.121). Superoxide dismutase activity was highest in PTX group but no statistically significant difference was found between the three groups (P = 0.305). The administration of PTX increases GPx activity and it may have some effect on tracheal scar formation which develops following tracheostomy.

Wound-healing modulation in upper airway stenosis-Myths and facts.

Wound healing plays a major role in the development of acquired subglottic stenosis. Pharmacologic treatment of subglottic stenosis must address both physiologic and pathologic healing processes. The relevant Pubmed and Ovid databases from 1960 to 2007 were systematically searched. Several modulating agents have been tested. Most of them were poorly investigated. Three modalities were thoroughly studied-steroids and antibiotics, mitomycin, and antireflux medications. However, there are conflicting data regarding their role in preventing and treating subglottic stenosis. Current data support to some extent the textbook suggestions of antibiotics, steroids, and antireflux treatment. As no other treatment options exist, we recommend using these modalities for pharmacologic modulation of subglottic stenosis. Mitomycin should still be considered as an unproven treatment; its use may be considered as an adjunct.

Effect of mitomycin in the surgical treatment of tracheal stenosis.

OBJECTIVE: To assess the capacity of high and low doses of the antimitotic drug mitomycin to prevent laryngeal stenosis in an animal model. METHODS: A prospective, randomized, double-blind, controlled study was carried out. End-to-end anastomosis was performed in 18 rabbits after tracheal annulus resection to produce inflammation. There were 3 treatment groups: topical saline (isotonic sodium chloride solution) and low-dose (0.2 mg/mL) and high-dose (0.5 mg/mL) topical mitomycin. RESULTS: A total of 107 procedures were performed: 54 surgical procedures, 35 fibrobronchoscopies, and 18 biopsies. The effect of mitomycin was dose related. In the high-dose mitomycin group, most rabbits progressed to stenosis with a percentage decrease in airway diameter that was significantly greater than in the other 2 groups (P <.001). The mean (SD) percentage of maximum stenosis in the high-dose group was 51% (22%). In the low-dose and saline groups, it was 18% (13%) and 16% (9%), respectively. No significant differences in tracheal stenosis between the low-dose mitomycin and saline groups were observed. Blinded histopathological analysis also showed no significant differences between the saline group and the low-dose mitomycin group. Compared with the other 2 groups, the high-dose mitomycin group had a significant increase in fibroproliferative tissue (P <.001). CONCLUSION: These results suggest that topical mitomycin is not effective for avoiding tracheal stenosis and may provoke the opposite effect if the dose is not carefully selected.

The preventive effect of halofuginone on posterior glottic stenosis in a rabbit model.

OBJECTIVE: The aim of this study was to investigate the preventive effect of halofuginone on posterior glottic stenosis (PGS) in an animal model. STUDY DESIGN: A randomized, controlled animal study. SUBJECTS AND METHODS: Sixteen male New Zealand White rabbits were used for this study. After the mucosa of posterior glottis was removed for producing PGS, the study group (eight rabbits) was given intraperitoneal halofuginone at 0.1 mg/kg/day for 4 weeks and saline was injected into peritoneum in the control group. At 4 weeks after injury, postsurgical changes of posterior glottis were evaluated by gross and histologic examination. RESULTS: PGS was induced by the mucosal stripping of the posterior glottis. The halofuginone-treated group showed less scarring and granulation tissue formation. Also, the degree of synechia was significantly less than that of control group. Histologic analysis showed the decreased fibrosis in the halofuginone-treated group. CONCLUSION: This study suggests that halofuginone can be helpful in preventing PGS after laryngeal injury.

Comparison between mitomycin C and chitosan for prevention of anterior glottic steno after CO2 laser cordectomy in dogs.

OBJECTIVE: To compare the effectiveness of an immediate application of topical mitomycin C (MMC) with chitosan for prevention of anterior glottic stenosis (AGS) after microsurgical resecting of both vocal fold with CO2 laser, including the anterior commissure, in a canine model. DESIGN: Prospective randomized experimental study. METHOD: Twenty-four canine larynges were injured by a microresecting procedure of both vocal folds with a CO2 laser. The dogs were randomly divided into three groups for treatment, respectively with MMC, chitosan, or isotonic sodium chloride solution (control) for 5 minutes immediately after surgery. One week after the initial surgery, three dogs in each group were randomly selected, the ultrastructures of the fibroblasts were examined with a transmission electronic microscope, and expression of basic fibroblast growth factor (bFGF) and transforming growth factor beta1 (TGF-beta1) were evaluated by enzyme-linked immunosorbent assay (ELISA). Three weeks after surgery, the remaining dogs' glottic web were lysed and repeatedly treated with MMC, chitosan, or isotonic sodium chloride solution. The glottic wound healing and AGS formation were examined every week, and all larynges were harvested and examined histologically 6 weeks after the initial surgery. RESULTS: Results included 1) transmission electronic microscope examination of the ultrastructures of the fibroblasts indicated that both MMC and chitosan inhibited the proliferation of fibroblast; 2) the expression of bFGF and TGF-beta1 increased both in the MMC group and the chitosan group, and the expression of bFGF in the chi-tosan group was higher than in the MMC group (P = .010), while the expression of TGF-beta1 was lower (P = .000);3) the extent of AGS formation was decreased both in the MMC group and the chitosan group, while it was less in the chitosan group than in the MMC group (P = .047); 4) the grade of collagen content between the MMC group and the chitosan group was not significantly different (P = .5). CONCLUSION: Chitosan is more effective in preventing AGS after CO2 laser cordectomy than MMC.

Refining indications for the use of mitomycin C using a randomized controlled trial with an animal model.

OBJECTIVES: To evaluate the effect of mitomycin on the repair of acquired subglottic stenosis and to define the optimal concentration of mitomycin that would minimize restenosis after repair. STUDY DESIGN AND SETTING: A randomized prospective model was used in which 20 ferrets (Mustela putorius furo) underwent simulated intubation injury that was then treated with CO2 laser lysis. RESULTS: Comparison of cross-sectional airway areas, after stenosis repair, showed no significant differences between control and mitomycin treatment groups. Comparison of histologic scores for both inflammation and mucosalization yielded no difference between control and treatment animals. CONCLUSIONS: Mitomycin C appeared to have no benefit when placed after repair of an acquired stenosis. SIGNIFICANCE: This study closely models the injury experienced by children with acquired subglottic stenosis. These data provide clear evidence that mitomycin is limited in its effect on established wounds and help further define its role as an adjuvant for surgery in the aerodigestive tract.

Use of silicone hearing aid mold material in laryngotracheal reconstruction.

OBJECTIVES: Endolaryngeal stenting in patients with irregularly shaped larynges can be challenging. In such cases, the use of a moldable yet reasonably rigid endolaryngeal stent is desirable. The purpose of this report is to describe our experience with silicone hearing aid material as a moldable endolaryngeal stent in a patient with an atypically shaped larynx. METHODS: A patient with relapsing polychondritis that resulted in complete stenosis of the subglottic airway underwent laryngotracheal reconstruction. Moldable silicone, commonly used to prepare ear canal molds for hearing aids, was molded into the neo-endolarynx to serve as a custom-made endolaryngeal stent. RESULTS: The patient tolerated the moldable silicone stent well and had a patent airway with epithelialization 8 months after removal. CONCLUSIONS: Silicone mold material is a suitable substance for endolaryngeal stenting. It conforms to the configuration of the individual's airway, is tolerated well, can be removed relatively easily, and is a useful alternative to prefabricated stents in laryngotracheal reconstruction.

Prevention of anterior glottic stenosis after bilateral vocal fold stripping with mitomycin C.

OBJECTIVE: To examine the effects of immediate application of topical mitomycin C (MMC) on the prevention of anterior glottic stenosis (AGS) after microsurgical stripping of both vocal folds, including the anterior commissure, in a canine model. DESIGN: Prospective randomized experimental study. INTERVENTIONS: Twelve canine larynges were injured by a stripping procedure of both entire membranous vocal folds. The dogs were randomly divided into 2 groups for treatment with 1.0 mg/mL of MMC or with isotonic sodium chloride solution (control) for 5 minutes immediately after surgery. Three and 6 weeks after surgery, the glottic webs were lysed and repeatedly treated with MMC or isotonic sodium chloride solution. The glottic wound healing and AGS formation were examined every week. Ten weeks after the initial surgery, all larynges were collected and examined histologically. RESULTS: The stripping procedure induced AGS, affecting 58% to 86% (mean, 72%) of the length from the anterior commissure to the vocal process in the control group. The application of MMC at the time of initial surgery significantly lowered the incidence and extent of the web formation (P = .004). The AGS lesions were resolved by web lysis and treatment with MMC, without significant local adverse effects. Histological staining for collagen and elastin revealed that MMC treatment did not induce excessive fibrotic or atrophic changes in the lamina propria of the vocal folds. CONCLUSION: Bilateral stripping of the membranous vocal folds induces significant AGS, which can be minimized by use of MMC at initial surgery.