Search

Objectives: Laryngeal transplantation research has been studied in various animal models. For in-depth, immunologybased transplantation research, however, a thoroughly studied animal model must exist. The purpose of this study was to develop a reliable surgical technique in mice to serve as a model for further study of laryngeal transplantation. Methods: Heterotopic laryngeal transplantation was attempted in 15 immunocompetent mice by use of modifications of previously described techniques established in rats. Results: Various microvascular techniques were used that led to 8 successful transplants (of 15) with patent vascularity at the time of sacrifice. The first 7 attempts at transplantation were unsuccessful because of technical difficulties related to vessel size, soft tissue traumatic injury, and venous congestion. Subsequently, 8 transplantation procedures were successfully performed after modifications of the surgical technique. Conclusions: This pilot study describes the reproducible surgical techniques performed in using mice for studying laryngeal transplantation. Mice are cost-effective and immunologically well studied, and are thus ideal for further laryngeal transplantation research. [ABSTRACT FROM AUTHOR]

Objectives: One treatment option for unilateral vocal fold paralysis (UVFP) is ansa cervicalis-to-recurrent laryngeal nerve (ansa-RLN) anastomosis to provide reinnervation to the affected vocal fold. The advantages of this treatment approach are that it 1) provides vocal fold tone, bulk, and tension, 2) is technically simple, and 3) does not preclude other medialization procedures. We present all patients who have undergone ansa-RLN anastomosis for UVFP at our institution. Methods: An Institutional Review Board-approved retrospective chart review was performed to include all patients who had undergone an ansa-RLN anastomosis procedure for UVFP at our institution. Data from clinical and endoscopic laryngoscopy with stroboscopy were recorded. Statistical analysis was performed on visual and perceptual vocal data. Results: A total of 46 patients were included in the study. Stroboscopic analysis and perceptual vocal evaluation was performed in a blinded fashion on the 21 patients who had preoperative and postoperative stroboscopy. Severity, roughness, breathiness, and strain all improved significantly over time. Glottic closure, vocal fold edge, and supraglottic effort all significantly improved after operation. Of the 38 patients with at least 3 months of follow-up, all except 1 demonstrated evidence of reinnervation. Conclusions: This technique for treating UVFP results in significant improvements in patients' voice and on visual examination. [ABSTRACT FROM AUTHOR]

Objectives: Dendritic cells (DCs) are key instigators of rejection after transplantation. Their distribution has not been systematically characterized in all locations of the larynx and its surrounding tissues. Methods: Rat larynges were stained with monoclonal antibodies identifying DCs. These cells were then enumerated by a new combination of techniques including immunofluorescence, confocal microscopy, and imaging software. Results: The vast majority of DCs were located in the epithelium and subepithelium of the airway; the mean DC density ranged from 9 cells per square millimeter (0.2% of cells) to 645 cells per square millimeter (10.3% of cells). Their density in the epithelium was 3 to 11 times higher than that in the subepithelium. Non-airway sites (thyroid, parathyroid, muscle, fat) had mean DC densities varying from 3 cells per square millimeter (0.2%) to 57 cells per square millimeter (0.8%). No DCs were detected in cartilage. Conclusions: Dendritic cells are concentrated in the laryngotracheal epithelium and subepithelium and represent a much smaller proportion in the other sites studied. A baseline for laryngeal DC population studies has been established, and a computerized model for consistent quantitation using confocal microscopy has been developed. This unique method will serve as a foundation for investigating DC trafficking after rat laryngeal transplantation. [ABSTRACT FROM AUTHOR]

Investigates the immunosuppressive effect of irradiation in the murine laryngeal transplantation model. Effectiveness of irradiation of donor organs in reducing acute rejection; Protection effect of organ irradiation; Timing and mode of delivery of the irradiation.

Using a rat model of laryngeal transplantation, we sought to define the relationships between acute laryngeal rejection grade (RG) and cyclosporin A (CSA) concentration and CSA dosage. Five recipient Lewis rat groups (N = 10 per group) were administered intramuscular CSA doses of 1.0 (group 1), 2.5 (group 2), 5.0 (group 3), 7.5 (group 4), and 10 mg/kg per day (group 5) for 14 days. Immediately before sacrifice, 5 mL of whole blood was obtained to assay CSA trough levels by high-performance liquid chromatography. The specimens were graded microscopically by blinded reviewers by day of RG, 0 to 14 days after transplantation, as described in earlier reports. Despite high intragroup variability in CSA levels, significantly different mean CSA concentrations were achieved among all CSA dosage groups: 1,2,3,4, and 5 (.0001 < p < .02). The mean laryngeal RGs did not test significantly different from each other with groups 3, 4, and 5 (RG, 2.3 ± 1.3 versus 1.9 ± 1.1 versus .1.7 ± 0.3, respectively, .2 < p < .6). The RG for group 1 was significantly greater than those for groups 2 through 5 (p < .001), and the group 2 RG was greater (p < .02) than those for groups 3, 4, and 5. Polynomial fitting was used to determine the continuous relationship between each individual specimen's CSA concentration and the RG. Significant pathological allograft rejection correlated with CSA concentrations below 250 ng/mL. [ABSTRACT FROM AUTHOR]

Discusses modifications in the rat laryngeal transplantation model, as well as results of a study using nonimmunosuppressed, allogenic transplantations, in order to define a rejection grading system. Transplantation between LBN donor rats and Lewis recipients; Increased rejection demonstrated by histologic criteria in seven categories and gross criteria in 5 categories.

Examines the effects of steroids in vitro organ irradiation to cyclosporine immunosuppression for laryngeal transplantation. Alterations in the mean severity of rejection episodes; Inhibition of cell division; Occurrence of nephrotoxicity.