Intralesional cidofovir therapy for laryngeal papilloma in an adult cohort

OBJECTIVES: To confirm the safety and efficacy of intralesional cidofovir in the management of laryngeal papilloma and to identify variables that correlate with number of injections needed to achieve remission. STUDY DESIGN: An open-trial prospective evaluation of the efficacy of intralesional cidofovir in subjects with laryngeal papilloma. METHODS: Fourteen adult subjects with biopsy-proven laryngeal papilloma were enrolled in a treatment study of intralesional cidofovir. Preprotocol disease duration ranged from 1 to 30 years with a mean duration of 7 years. Subjects received monthly injections of cidofovir with a maximum dose of 37.5 mg per injection in 6 cc saline (6.25 mg/mL). Injections were repeated until no papilloma could be visually identified during an intraoperative evaluation. After disease remission was achieved, subjects received an additional injection. All injections occurred during suspension microlaryngoscopy. RESULTS: All subjects have achieved disease remission using an injection-only treatment protocol. No additional laryngeal scarring or systemic toxicity was identified. On average, 6 injections were required to achieve remission. Preprotocol disease duration and anatomical staging correlated positively with the number of injections required for disease remission. CONCLUSIONS: Intralesional injection of cidofovir is an excellent treatment option with limited local and systemic toxicities. The injection therapy regimen requires perseverance from both patient and surgeon. Remission of disease can be achieved in adults with laryngeal papilloma.     

Viscoelastic measurements after vocal fold scarring in rabbits--short-term results after hyaluronan injection

CONCLUSIONS: The scarring model resulted in significant damage and elevated viscoelasticity of the lamina propria. Hyaluronan preparations may alter viscoelasticity in scarred rabbit vocal folds. OBJECTIVES: Vocal fold scarring results in stiffness of the lamina propria and severe voice problems. The aims of this study were to examine the degree of scarring achieved in the experiment and to measure the viscoelastic properties after injection of hyaluronan in rabbit vocal folds. MATERIALS AND METHODS: Twenty-two vocal folds from 15 New Zealand rabbits were scarred, 8 vocal folds were controls. After 8 weeks 12 of the scarred vocal folds received injections with 2 types of cross-linked hyaluronan products and 10 scarred folds were injected with saline. After 11 more weeks the animals were sacrificed. After dissection, 15 vocal folds were frozen for viscoelastic measurements, whereas 14 vocal folds were prepared and stained. Measurements were made of the lamina propria thickness. Viscoelasticity was measured on intact vocal folds with a linear skin rheometer (LSR) adapted to laryngeal measurements. RESULTS: Measurements on the digitized slides showed a thickened lamina propria in the scarred samples as compared with the normal vocal folds (p<0.05). The viscoelastic analysis showed a tendency to stiffening of the scarred vocal folds as compared with the normal controls (p=0.05). There was large variation in stiffness between the two injected hyaluronan products.     

Prevention of vocal fold scarring by topical injection of hepatocyte growth factor in a rabbit model

OBJECTIVES/HYPOTHESIS: Vocal fold scarring disrupts the layer structure of the vocal fold lamina propria that is essential for optimal mucosal vibration. Prevention of vocal fold scarring remains challenging. Hepatocyte growth factor (HGF) has strong antifibrotic activity. The authors' previous studies have found that HGF stimulates hyaluronic acid production and suppresses collagen production from vocal fold fibroblasts, suggesting that HGF has therapeutic potential in prevention of vocal fold scarring. The present study aimed to demonstrate the effects of HGF on vocal fold scarring in an in vivo rabbit model. STUDY DESIGN: Animal experiment. METHODS: The vocal fold mucosa was stripped unilaterally in 20 rabbits, then HGF or saline (sham-treated group) was immediately injected into the injured site. At 6 months after the procedure, histological, rheological, and physiological examinations of vibratory behavior were completed. RESULTS: Histological examination revealed excessive collagen deposition and disorganized elastin in the sham-treated group, whereas the HGF-treated group presented with better wound healing exhibiting less collagen deposition. Contraction of the injured vocal folds observed in the sham-treated group did not occur in the HGF-treated group. Rheological data indicated that the HGF-treated vocal folds were less stiff and viscous compared with the sham-treated group. Mucosal vibration of HGF-treated vocal folds appeared much better than the sham-treated group in terms of phonation threshold pressure, vocal efficiency, mucosal wave amplitude, and glottal closure. CONCLUSION: Hepatocyte growth factor proved to be useful in preventing vocal fold scarring and maintaining viscoelastic shear properties of the vocal fold.     

Long-term outcomes of basic fibroblast growth factor treatments in patients with vocal fold scarring,aged vocal fold,and sulcus vocalis

ObjectiveFibrotic changes in the vocal fold mucosa have been observed in patients with vocal fold scarring, aged vocal fold, and sulcus vocalis, which often lead to severe voice disorders. Previous research suggests that the basic fibroblast growth factor (b FGF) improves variations in vocal fold properties [1,2]. Although clinical studies on b FGF treatments have been conducted [3,4,5], these studies only demonstrated the efficacy of this drug over a short period. The present study is the first to investigate the long-term efficacy of b FGF treatment.Methodsb FGF injections were performed in six patients from January of 2016 to December of 2017 at our institution. Patient follow-up continued for at least two years after the last injection. Three patients had vocal fold scarring, two had aged vocal fold atrophy, and one patient had sulcus vocalis. Each vocal fold was injected with 10 µg of b FGF four times. Voice and stroboscopic examinations were performed after surgery (at one month, three months, six months, one year, two years). Fundamental frequency, maximum phonation time (MPT), mean flow rate (MFR), amplitude perturbation quotient (APQ), pitch perturbation quotient (PPQ), and noise-to-harmonic ratio (NHR), and voice handicap index-10 (VHI-10) were examined and compared statistically between the pretreatment time and at each posttreatment time point.ResultsThe speaking F0 had an obvious decreasing tendency, with significant differences suggesting the increase in volume in the vocal folds. Aerodynamic parameters also showed small improvements. The most remarkable improvement was observed in the acoustic parameters, indicating that the treatment could improve the vocal fold to make vibrations symmetrically and regularly for a long period. Achievement of symmetry and regularity on vocal fold vibrations suggested the property changes had happened in the vocal folds. Consequently, the score of VHI-10 had improved, indicating high patient satisfaction with this treatment.Conclusionb FGF injections could be a reliable treatment option for diseases that deteriorate the property of vocal fold.     

Stepped-dose protocol of cidofovir therapy in recurrent respiratory papillomatosis in children

OBJECTIVE: To evaluate a stepped-dose protocol for intralesional injection of cidofovir in children with recurrent respiratory papillomatosis (RRP). DESIGN: Prospective, nonrandomized case series. SETTING: Tertiary care children's hospital. PARTICIPANTS: Eleven children undergoing evaluation for RRP from June 1, 2000, through December 31, 2001. INTERVENTION: Intralesional injection of cidofovir was performed after microlaryngoscopy and carbon dioxide laser treatment. Patients received 4 monthly injections at a concentration of 5 mg/mL and returned 1 month after the last injection for follow-up. Patients with recurrent or recalcitrant disease then started a series of 4 monthly injections at a concentration of 10 mg/mL. OUTCOME MEASURE: Papilloma stage (0-3) documented at multiple subsites by means of serial microlaryngoscopy. We calculated a severity score by summing the scores at all affected subsites. RESULTS: The severity score decreased in each of the 11 patients during the course of therapy, from a mean +/- SD of 13.7 +/- 6.0 at enrollment to 2.1 +/- 3.4 at 1-month follow-up. Six patients experienced complete resolution (stage 0) and 4 others had mild disease (stage, 相似文献   

Fibronectin and adhesion molecules on canine scarred vocal folds

OBJECTIVE: To examine the expressions of fibronectin and other adhesion molecules on the scarred vocal folds in a short- and long-term animal model. STUDY DESIGN: Animal model. METHODS: Six beagles' vocal folds were stripped unilaterally and left untreated. After wounding the vocal folds were harvested from three dogs at 2 months and three dogs at 6 months. The untouched vocal fold was used as a control, and the stripped vocal fold as scarred. Subsequently, the expressions of fibronectin, cadherin, syndecan-1 and syndecan-4 on both vocal folds were examined by immunohistochemical and image analysis. RESULTS: Compared with the control vocal folds, fibronectin significantly increased in the superficial layer of the lamina propria on the scarred vocal folds at both 2 and 6 months. Co-deposition of collagen was observed only at 6 months. Syndecan-4 was significantly overexpressed at the basal layer cells of the epithelium at both 2 and 6 months. No significant expression of either cadherin or syndecan-1 was detected. CONCLUSIONS: Scar characteristics at 2 and 6 months are not identical, suggesting that a 2-month period may not be a sufficient to study vocal fold scarring. Adhesion molecules are important in reorganization of extracellular matrix during wound healing because of their binding and adhesion characteristics. The results indicate that fibronectin might be important in providing a scaffold for the deposition of other proteins such as collagen, and the binding characteristics might affect the stiffness of the scarred vocal fold. Prolonged expression of syndecan-4 may reflect the role of focal adhesion during the assembly of scar structure. Ultimately, better understanding of the histological features of the scarred vocal fold might lead to new approaches to treatment.     

Natural history of adult-onset laryngeal papillomatosis following multiple cidofovir injections

OBJECTIVES: A prospective study was performed to assess the intermediate and long-term efficacy of intralesional cidofovir therapy associated with surgical excision in laryngeal papillomatosis in adults. METHODS: Endoscopy with intralesional injection of cidofovir 5 mg/mL was performed 3 times at 4-week intervals. The concentration was later increased to 7.5 mg/mL and the interval between injections shortened to 2 weeks. Further treatment was performed at 3 or 6 months, depending on the evolution of the papillomas. After complete remission, the treatment was stopped and the patients were reviewed every 6 months. RESULTS: Nineteen patients completed the protocol, with a mean of 4.5 injections each. Complete remission was obtained in 17 cases (89%) after a mean of 3.8 procedures. Remission was stable after a mean follow-up of 24 months (range, 8 to 57 months). With higher cidofovir concentrations at shorter intervals, patients needed fewer injections to achieve remission (mean, 2.1 versus 4.7 injections). CONCLUSIONS: The effectiveness of intralesional cidofovir therapy in adult-onset recurrent respiratory papillomatosis was impressive. Once obtained, complete remission was stable on intermediate or long-term follow-up. The concentration and the interval between injections seemed to influence the number of injections necessary to achieve remission.     

Viscoelastic measurements after vocal fold scarring in rabbits—short-term results after hyaluronan injection

Abstract

Conclusions. The scarring model resulted in significant damage and elevated viscoelasticity of the lamina propria. Hyaluronan preparations may alter viscoelasticity in scarred rabbit vocal folds. Objectives. Vocal fold scarring results in stiffness of the lamina propria and severe voice problems. The aims of this study were to examine the degree of scarring achieved in the experiment and to measure the viscoelastic properties after injection of hyaluronan in rabbit vocal folds. Materials and methods. Twenty-two vocal folds from 15 New Zealand rabbits were scarred, 8 vocal folds were controls. After 8 weeks 12 of the scarred vocal folds received injections with 2 types of cross-linked hyaluronan products and 10 scarred folds were injected with saline. After 11 more weeks the animals were sacrificed. After dissection, 15 vocal folds were frozen for viscoelastic measurements, whereas 14 vocal folds were prepared and stained. Measurements were made of the lamina propria thickness. Viscoelasticity was measured on intact vocal folds with a linear skin rheometer (LSR) adapted to laryngeal measurements. Results. Measurements on the digitized slides showed a thickened lamina propria in the scarred samples as compared with the normal vocal folds (p <0.05). The viscoelastic analysis showed a tendency to stiffening of the scarred vocal folds as compared with the normal controls (p =0.05). There was large variation in stiffness between the two injected hyaluronan products.     

Drug delivery system of hepatocyte growth factor for the treatment of vocal fold scarring in a canine model

OBJECTIVES: Vocal fold scarring remains a therapeutic challenge. Previous studies have indicated that hepatocyte growth factor (HGF), a strong antifibrotic element, has therapeutic potential for restoring scarred vocal folds. To enhance the effect of HGF in vivo, we developed a novel drug delivery system (DDS) in which HGF is embedded in gelatin hydrogel and continuously released over a period of 2 weeks. In the present study we investigated the therapeutic efficacy of the HGF DDS on vocal fold scarring by using a canine model. METHODS: The vocal folds of 8 beagles were unilaterally scarred by stripping the entire layer of the lamina propria. The contralateral vocal folds were kept intact as normal controls. One month after the procedure, hydrogels (0.5 mL) containing 1 microg of HGF were injected into the scarred vocal folds of 4 dogs (HGF-treated group), whereas hydrogels containing saline solution were injected in the other 4 dogs (sham group). Histologic and vibratory examinations were completed for each group 6 months after the initial surgery. RESULTS: The excised larynx experiments showed significantly better vibration in terms of mucosal wave amplitude and glottal closure in the HGF-treated group compared to the sham group. Histologic evaluation of the vocal folds indicated remarkable reduction in collagen deposition and tissue contraction, with favorable restoration of hyaluronic acid and elastin in the HGF-treated group. CONCLUSIONS: The present findings suggest that the novel HGF DDS may provide favorable effects in restoring the vibratory properties of scarred vocal folds.     

Serial office-based intralesional injection of cidofovir in adult-onset recurrent respiratory papillomatosis

Intralesional injection of cidofovir is used in the treatment of recurrent respiratory papillomatosis as an adjuvant therapy after microsurgical excision and CO2 laser therapy. This is conventionally done in the operating room with the patient under general anesthesia. We report our experience with 5 patients with adult-onset recurrent respiratory papillomatosis who were treated with intralesional injections of cidofovir after recurrence of their papillomatosis. These injections were given monthly in the office without the use of general anesthesia. Before cidofovir injection, all patients required repeated CO2 laser treatments at intervals of less than 5 months. We injected 7.5 mg/mL of cidofovir transorally into the papillomas under office telescopic control. These injections were given monthly for 3 consecutive months. The patients were then followed up for 2 to 10 months after therapy to monitor the size of the papillomas. In all 5 patients, partial remission of the laryngeal papillomatosis was noted during the follow-up period. Their need for repeat microsurgery was delayed, and their vocal function improved. Intralesional injection of cidofovir in an office setting appears to be safe and effective. It might be more convenient and cost-effective than performing the same procedure in the operating room with the patient under general anesthesia.     

Growth factor therapy for vocal fold scarring in a canine model

Vocal fold scarring remains a therapeutic challenge. Hepatocyte growth factor (HGF) has strong antifibrotic activity and has proved to have therapeutic potential in restoration of scar tissues such as liver cirrhosis and lung fibrosis. The present study aimed to clarify the effects of HGF injection into scarred vocal folds in a canine model. Canine vocal folds were stripped unilaterally and treated with intracordal injection of saline solution (sham group), HGF (HGF group), or HGF with cultured autologous normal vocal fold fibroblasts (Fb/HGF group) 1 month after injury. The larynges were harvested 6 months after the initial injury and then subjected to vibratory and histologic examination. The results of vibratory examinations in the excised larynx setup revealed that phonation threshold pressure significantly increased and vocal efficiency was significantly reduced in all treated groups as compared to normal data obtained from normal canine larynges. However, the HGF group presented much better results than both the sham and Fb/HGF groups in terms of mucosal wave amplitude and incidence of vocal fold bowing, glottal incompetence, and phase asymmetry. The histologic data indicated a significant increase of collagen in both the sham and Fb/HGF groups, while normal levels of collagen were found in the HGF group. Tissue contraction of the lamina propria was also observed in both the sham and Fb/HGF groups, but was barely detectable in the HGF group. Although the HGF-treated vocal folds appeared to require more driving forces for vibration, HGF might prevent excessive collagen deposition and tissue contraction and thus reduce the effects of scarring on the vibratory properties of the vocal folds. From these data it is concluded that HGF has considerable potential in the treatment of vocal fold scarring.     

Viscoelastic and histologic properties in scarred rabbit vocal folds after mesenchymal stem cell injection

Objective/Hypothesis: The aim of this study was to analyze the short‐term viscoelastic and histologic properties of scarred rabbit vocal folds after injection of human mesenchymal stem cells (MSC) as well as the degree of MSC survival. Because MSCs are antiinflammatory and regenerate mesenchymal tissues, can MSC injection reduce vocal fold scarring after injury? Study Design: Twelve vocal folds from 10 New Zealand rabbits were scarred by a localized resection and injected with human MSC or saline. Eight vocal folds were left as controls. Material and Methods: After 4 weeks, 10 larynges were stained for histology and evaluation of the lamina propria thickness. Collagen type I content was analyzed from six rabbits. MSC survival was analyzed by fluorescent in situ hybridization staining from three rabbits. Viscoelasticity for 10 vocal folds was analyzed in a parallel‐plate rheometer. Results: The rheometry on fresh‐frozen samples showed decreased dynamic viscosity and lower elastic modulus (P < .01) in the scarred samples injected with MSC as compared with the untreated scarred group. Normal controls had lower dynamic viscosity and elastic modulus as compared with the scarred untreated and treated vocal folds (P < .01). Histologic analysis showed a higher content of collagen type 1 in the scarred samples as compared with the normal vocal folds and with the scarred folds treated with MSC. MSCs remained in all samples analyzed. Conclusions: The treated scarred vocal folds showed persistent MSC. Injection of scarred rabbit vocal folds with MSC rendered improved viscoelastic parameters and less signs of scarring expressed as collagen content in comparison to the untreated scarred vocal folds.     

Regeneration of Aged Vocal Fold: First Human Case Treated With Fibroblast Growth Factor

Background/Objectives: Aged vocal folds are characterized by atrophy of the mucosa, which causes dysphonia and is difficult to treat. We have revealed a therapeutic potential of basic fibroblast growth factor (bFGF) for tissue regeneration of the aged vocal fold. We report here the first human case that has been treated with bFGF. Study Design: Institutional review board approved clinical human trial. Methods: A 63‐year‐old man with atrophied vocal folds was treated by local injection of 10 μg of bFGF into the left vocal fold under topical anesthesia. The effects of the injection were examined after 1 to 3 months by videostroboscopy, acoustic and aerodynamic measurements. Results: The atrophy of the vocal fold was improved at 1 week after the injection and glottic gap disappeared. Aerodynamic and acoustic parameters also showed remarkable improvement. These positive effects were maintained up to 3 months. Conclusion: The first case with aged vocal folds treated with bFGF administration is presented. The results are encouraging, suggesting therapeutic effects of bFGF for atrophied vocal folds in human.     

Injection laryngoplasty for management of unilateral vocal fold paralysis

PURPOSE OF REVIEW: The purpose of this review is to provide an up-to-date review of injection laryngoplasty technique and currently available injectable materials in the management of unilateral vocal fold paralysis (UVP). RECENT FINDINGS: Many new materials are currently available as substances for injection laryngoplasty. These materials have been developed along distinct of lines reasoning that address the inherent shortcomings of the previously available injectable substances, namely, poor tissue biocompatibility and poor persistence within the larynx. Accordingly, the past decade has seen heightened efforts toward developing implants with improved biocompatibility and longevity. The past year has witnessed publications reporting animal studies and, on occasion, human clinical trials involving the intralaryngeal injection of calcium hydroxyl-appetite, autologous fascia, particulate silicone and hyaluronic acid derivatives, and others, for managing glottic insufficiency. SUMMARY: In recent years, the application of injection laryngoplasty to unilateral vocal fold paralysis (UVP) has regained popularity. The technique of injection laryngoplasty has several appealing qualities including relative technical ease, low cost, and wide availability in many clinical settings. A growing number of injectable substances have been developed and tested in the clinical setting of glottic insufficiency. When used to manage unilateral vocal fold paralysis, however, injection laryngoplasty has one irrefutable shortcoming: an inability to address posterior glottic insufficiency. Therefore, while injection laryngoplasty technique becomes increasingly popular for vocal fold augmentation in cases vocal fold paresis, atrophy, and scarring, its role in the treatment of UVP should be limited to cases with an appropriate glottal defect. These techniques should be considered as part of a complimentary armamentarium with framework surgery.     

DiHA (dextranomers in hyaluronan) injections for treatment of insufficient closure of the vocal folds: early clinical experiences

OBJECTIVE: To determine the clinical effects of injecting DiHA (a mixture of dextranomer molecules and 1% hyaluronan solution in equal proportions) as a "space filler" into the vocal folds of patients experiencing insufficient closure of the vocal folds resulting from either unilateral vocal fold paralysis or bowed vocal folds. STUDY DESIGN: A consecutive series of patients with insufficient closure of the vocal folds treated with DiHA injections and prospectively followed up with videostroboscopy and voice recordings that were evaluated by expert panels. METHODS: During a 21/2-year period, 14 patients with insufficient closure of the vocal folds were included. Six had a unilateral vocal fold palsy and 8 patients had "bowed" vocal folds. DiHA was injected into one vocal fold. Laryngoscopic examination and voice recordings were performed pre- and postoperatively. Expert panels did the evaluation of the stroboscopy examination and the perceptual voice analysis. RESULTS: Three patients were operated on with local and 11 under general anesthesia. All patients with unilateral palsy improved their stroboscopic status regarding both the wave and the closure after injection. Also, their voice parameters were significantly improved. Among the patients with bowed vocal folds, all except 2 showed an improvement in the glottic wave, 5 of 8 improved in glottic closure, and 3 improved their voice parameters significantly. CONCLUSION: This early clinical experience indicates that DiHA fulfills most of the requirements of an ideal "space-filling" substance for voice restoration in patients experiencing insufficient vocal fold closure.     

Viscoelasticity of rabbit vocal folds after injection augmentation

OBJECTIVES/HYPOTHESIS: Vocal fold function is related to the viscoelasticity of the vocal fold tissue. Augmentation substances used for injection treatment of voice insufficiency may alter the viscoelastic properties of vocal folds and their vibratory capacity. The objective was to compare the mechanical properties (viscoelasticity) of various injectable substances and the viscoelasticity of rabbit vocal folds, 6 months after injection with one of these substances. STUDY DESIGN: Animal model. METHODS: Cross-linked collagen (Zyplast), double cross-linked hyaluronan (hylan B gel), dextranomers in hyaluronan (DHIA), and polytetrafluoroethylene (Teflon) were injected into rabbit vocal folds. Six months after the injection, the animals were killed and the right- and left-side vocal folds were removed. Dynamic viscosity of the injected substances and the vocal folds was measured with a Bohlin parallel-plate rheometer during small-amplitude oscillation. RESULTS: All injected vocal folds showed a decreasing dynamic viscosity with increasing frequency. Hylan B gel and DiHA showed the lowest dynamic viscosity values, and vocal folds injected with these substances also showed the lowest dynamic viscosity (similar to noninjected control samples). Teflon (and vocal folds injected with Teflon) showed the highest dynamic viscosity values, followed by the collagen samples. CONCLUSION: Substances with low viscoelasticity alter the mechanical properties of the vocal fold to a lesser degree than substances with a high viscoelasticity. The data indicated that hylan B gel and DiHA render the most natural viscoelastic properties to the vocal folds. These substances seem to be appropriate for preserving or restoring the vibratory capacity of the vocal folds when glottal insufficiency is treated with augmentative injections.     

Intralaryngeal application of a miniaturized ultrasonic probe

We developed a method for performing intralaryngeal ultrasonography. Normal larynges were obtained from 10 cadavers and examined using an intraluminal ultrasonic tomography apparatus connected to a radial scanning 20 MHz miniaturized probe. The larynx was placed in a bath filled with physiologic saline. and the probe was inserted through the forceps channel of the fiberscope (6 mm diameter). A horizontal ultrasonic image of the vocal fold was obtained. Histologic sections of the larynx were compared with the ultrasonic images. The mucosa in the membranous region of the vocal fold was comprised of three layers ultrasonographically. The epithelium and superficial layer of the lamina propria were visualized as a high echo (hyperechoic) region, the intermediate layer of the lamina propria was visualized as a low echo (hypoechoic) region and the deep layer of the lamina propria was seen as a hyperechoic region. The vocal fold structure can be visualized by intralaryngeal ultrasonography using the filling method. This method may be clinically useful for the detection of tumors involving the vocal folds.     

Comparison of microflap healing outcomes with traditional and microsuturing techniques: initial results in a canine model

A prospective, blinded study was designed to determine whether placement of a microsuture in epithelial defects created on canine vocal folds results in histologically demonstrable improved heating. Epithetial defects similar to those created during microflap removal were made by means of traditional microsurgical techniques on both vocal folds of 4 adult dogs. One vocal fold defect on each dog was then closed with a single microsuture placed through the laryngoscope. The larynges were harvested approximately 6 weeks later, and blinded histologic quantification of scar formation was performed. Microsutures resulted in less scarring in all but 1 of the larynges studied. Unsutured vocal folds exhibited a 75% larger average scar cross-sectional area. Although the sample size was insufficient to establish statistical significance, the observed difference in scar formation between microsutured and unsutured vocal folds suggests that primary closure with a microsuture in the canine model results in less scarring than when healing occurs by secondary intention.     

一侧膈神经上根选择性神经再支配环杓后肌的实验研究

目的 探讨一侧膈神经上根选择性神经再支配环杓后肌的可行性和有效性.方法 8只健康雄性青年Beagle犬作为实验动物,全麻下切断Beagle犬左侧膈神经上根与左侧喉返神经,两断端通过游离神经桥接的方式吻合,并将同侧喉返神经内收肌支切断并植入同侧环杓后肌中;右侧不做任何处理,作为正常对照侧.于手术前、神经修复术后即刻、术后6个月分别行电子喉镜和喉肌电图检查,在最后一次检查后处死动物,取双侧环杓后肌和喉内段喉返神经行组织学检查并与对侧比较.结果 术前8只犬的双侧声带运动正常,术后即刻左侧声带固定,术后6个月均恢复了吸气性外展运动.术前8只犬双侧环杓后肌均能记录到自发肌电位,并引出诱发电位;术后即刻左侧环杓后肌呈电静息,未记录到诱发电位;术后6个月均能记录到自发肌电位,并引出诱发电位,而且两种电位幅度分别与术前比较差异均无统计学意义(均为P>0.05).环杓后肌Masson染色示两侧肌肉纤维相对截面积、胶原纤维相对截面积、肌肉/胶原纤维截面积比差异均无统计学意义(均为P>0.05).喉内段喉返神经甲苯胺蓝染色后示神经纤维分布较均匀密集,且左右两侧喉返神经有髓神经纤维数量差异无统计学意义(P>0.05).结论 左侧膈神经上根选择性神经再支配环杓后肌能有效避免神经错向再生,恢复声带的生理性外展运动.     

Treatment of vocal fold scarring: rheological and histological measures of homologous collagen matrix

The current treatment options for dysphonia secondary to vocal fold scarring are limited. Few studies address changes in the lamina propria, which is critical to vocal fold biomechanical properties and voice production. Using rheological and histological measures of homologous collagen matrix (HCM)-injected vocal folds, we assessed HCM's potential for providing bulk and restoring biomechanical performance. Twenty rabbits underwent bilateral vocal fold scarring. After 10 weeks of scar maturation, the rabbits had unilateral injections of HCM or saline solution. Ten weeks after the injections, histological studies revealed well-defined collagen globules distributed throughout the lamina propria and underlying muscular tissue. Significantly more procollagen was observed in the HCM-treated group. No significant differences in elastic shear modulus or dynamic viscosity were found between the treatment groups. This study demonstrates that HCM is an inert, relatively stable injectate that may serve well for medialization but does not appear to improve the dynamic properties of the lamina propria.