Résumé :
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Degenerative dystrophy of the pharyngeal muscles in OPMD causes fibrosis with swallowing disorders and a decreased relaxation of the cricopharyngeal muscle (CPM) (muscle of the upper esophageal sphincter, UES). The myotomy of the UES improves only a partial and transitory improvement but do not prevent the degradation of the pharyngal muscles. Cells cultures exhibited a reduced myogenicity, as well as a rapid decrease in proliferative lifespan, but the myoblasts isolated from unaffected muscles did not show the defects observed in CPM cultures. This suggests that myoblast autografts from unaffected muscles, injected into the dystrophic muscles, may be a useful therapeutic strategy to restore contractility to pharyngeal muscles. The protocol (PHRC 2002) performed is a graft of autologous cell muscles isolated from quadriceps (Q) or sternocleidomastoid (SCM) muscles into the pharyngeal muscles in OPMD. It is firstly a safety study of both autograft and surgical procedure, that may improve both swallowing and the dystrophic pharyngeal muscles. Biopsies of the selected muscles (7SCM, 5Q) were performed 4 weeks after the initial biopsies. The average number of myoblasts amplified for transplantation was of 240X106 myoblasts. Myoblasts were injected under general anesthesia into pharyngeal muscles, following UES myotomy. At 2 years, the major criteria of evaluation was based on the quality of pharyngeal propulsion at both videoendoscopy os swallowing (VESS) and videofluoroscopy (VFS). The secondary criteria of evaluation were the global swallowing (questionnaires, time of swallowing) and the tolerance of graft. Each patient himself constituted its referenceThere was no complication and the procedure was safe and well tolerated.Preoperatively, at VESS and VFS, 12 and 10 patients exhibited a decrease of pharyngeal propulsion respectively, and all a UES dysfunction. At 2 years, at VESS, the pharyngeal propulsion was normal in one patient, decreased in 10 and severely impaired in 1. At VFS, a decreased pharyngeal propulsion was observed in all patients, which was severely altered in 4. Preoperatively, for the questionnaire of Salassa (grade 0, normal, to 5), nine patients exhibited grade 2 and three a grade 3; the mean of questionnaire of McHorney was of 35. At 2 years, the score of Salassa was grade 0, 1 and 2 in 3, 6, and 3 patients respectively. The mean of questionnaire of McHorney was of 19. The mean time of swallowing 80mL of water was 24s preoperatively and 10s at 2 years. The study demonstrates that global swallowing is improved and the graft well tolerated. Although restauration of dystrophic pharyngeal muscles is limited, graft may prevent muscular degradation usually observed in OPM patients.
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