Abstract:

Objective   To study the morphometric and qualitative histopathologic changes of tensor veli palatini in OSAHS patients, and to explore whether neurogenic lesions could be a contributory factor. Methods  Biopsies were obtained by uvulopalatopharyngoplasty in 30 OSAHS patients. Control specimens of tensor veli palatini were retrieved in 10 patients with chronic tonsillitis. The morphological alteration was evaluated using Trichrome HE，Masson staining , AchE histochemistry stain and a transmission electron microscope(TEM). Results  In OSAHS patients, the scarsof myofibers were decreased, but the scars  of collagen fibers were increased, the ratio of scars  of myofibers to those of collagen fibers was progressively decreased. TEM：The structure of myofibril was confused, some myofilaments and part of the Z zones dissolved, some breaks disappeared, sarcoplasms   dilated cystiformly and tubularly, the mitochondria  concentrated among the muscle fibers, the myelinated nerve fibers degenerated, the myelin sheath loosened and regional edema occurred. The levels of AchE expression in myoceptors were decreased. Conclusion  The myoceptors and nervus peripheralis of tensor veli palatini in OSAHS patients have great morphologically change. The degree of pathological changes and the morphometric and qualitative histopathologic changes of tensor veli palatini is positively correlated. The denervation of tensor veli palatini may play  an important  role in the etiopathogenesis of OSAHS.

Key words: apnea; tensor veli palatini; morphology; denervation