The Investigation Of The Histological And Structural Changes Of The Uvula In Obstructive Sleep Apnea Syndrome

ObjectiverTo investigate the histological structural and ultrastructural change of the uvula and the correlation of AMI, Sa02 and minimum Sa02 of the patients in obstructive sleep apnea syndrome(OSAS), find out the theoretical proofs of the functional change of soft palate muscles (uvula etc), provide references to the clinic for selecting operating method and improve the operation. Method Fibred endoscope Mtlller examination, MRI and PSG were applied;20 cases of OSAS mainly obstructed at the soft palate level were selected and the uvulas were resected by palatopharyngoplasty as experiment group;5 male cases without OSAS past history and related diseases were selected and the uvulas were taken by microscopy as control group. Light microscopy and electron microscopy were applied to observe the histology structure and ultrastructure; half-quantity-analytical method was applied to investigate the change of histological structure and ultrastructure in OSAS. Result Electron microscopic: the crests of the mitochondrias broken and lysed, the granules of the matrix lost obviously, and the completeness of the inner and outer membranes disappeared; the difference between Flameng scoredexperiment group and control group was of statistical significance (P<0.05); the Flameng score, AHI, Sa02 and minimum Sa02 were correlated in control group(r=0. 64, r= -0.72, r= -0.64 respectively, P<0. 05).The structure of myofibril confused. Some myofilaments dissolved; part of the Z zones arrayed as serrata;some breaks disappeared; sarcoplasms dilated cystiformly and tubularly;the mitochondrias concentrated among the muscle fibers, and they were of various size and degenerated; the nuclears of the muscle cells pyknosed slightly; vesicle degeneration appeared in the axon of muscle fibers. The biological membranes were broken with various degrees; the myelinated nerve fibers and the axons degenerated; the lysosomes and endoplasmic reticulums broke down. Light microscopy: In the OSAS group: The squalors epithelium of mucosa hyperplasia papillarily; high edema appeared under the mucosa; the blood vessel dilated; the submucosa mucus gland hyperplasia with various degree; the duct dilated; the submucosa lymphoid tissue hyperplasiaed and lymphoid follicles formed. Striated muscles were eroded by the glands; the muscle fibers deformed and vacuolated; striated muscles disappeared; part of the muscle fibers atrophied or were replaced by fibrous tissues. The ratio of fibrous tissue and fat tissue had positive correlation to AHI (r=0. 465, r=0.647, P<0.05); the muscular tissues had negative correlation to AHI(r= --4-0.760, P<0.05) ; the proportion of fat tissues was negatively correlated to the average Sa02(r= -0.508, P<0.05). Conclusion The ultrastructural changes of mitochondria, the relatively less muscular tissues, the relatively more fibrous tissues and fat tissues, and the edema of nervous tissues result in the descent of the muscle tension, the increase of pharynx wall' s compliance and the constriction of respiratory tract, make the airway cave in easily, and is the main cause of aggravating the ischemia of OSAS patients obstructed at the soft palate level.