The Investigation Of The Relationship Between Histologica And Structural Changes Of The Uvula And Obstructive Sleep Apnea-Hypopnea Syndrome

Objective: This study was conducted to investigate histopathological changes of uvula tissues in patients with obstructive sleep apnea-hypopnea syndrome ( OSAHS ) and correlation between the changes and OSAHS .Method: Uvulas were obtained by uvulopalatopharyngoplasty in 24 patients with moderate OSAHS and 10 patients with severe OSAHS and by autopsy in 10 individuals not known to have OSAHS. Light microscopy (×100 ) were applied to observe the histology structure, including the shape, density and arrangement of muscle and spatium intermusculare and epithelial tissue . Half-quantity-analytical method was applied to investigate the changes.Result: The structure of epithelial lining in OSAHS are complete, but there are some abnormal changes , including the enlargement of intercellular space with interstitial edema, epithelium swelling , small vessels encroaching basal layer ,and inflammation and edema in mucosa accompanying plasma cell infiltration . The thickness of the lamina propria ( an index of interstitial edema ) was also significantly increased in patients with OSAHS compared with controls (0.92±0.21 mm vs 0.24±0.07 mm, respectively; P<0.001) .The thickness of the the lamina propria was significantly increased in patients with severe OSAHS compared with moderate OSAHS . ( 1.03±0.11mm vs 0.24±0.07 mm, respectively ; P<0.001 ). The thickness of the lamina propria was significantly increased in patients with different BMI.( 24≤BMI≤28 VS BMI >28 ) , ( 1.03±0.11 mm vs 0.24±0.07 mm, respectively ; P<0.001 ) Average quantity of muscle in cross section of uvula were significant difference between OSAHS and controls ( 85.47士29.54 vs 149.70士22.68,respectively ; P<0.001)and between moderate OSAHS and severe OSAHS ( 117.70士32.09 vs 72.04士14.47 ,respectively;P<0.001) But there is no statistically significant difference among OSHAS with different BMI. Muscle fibers in control group line up in order ,link compactly, and have regular shape .The anomalistic arrangement of muscle in OSAHS group were worsen gradually with the severity of OSAHS compared with regular muscle form in control group.Conclusion: Apparent pathologic changes of mucous and muscle of uvulas in patients with OSAHS were founded , including thickening and inflammation of mucous, decreasing of muscle density ,morphological changes of muscle, degeneration and so on . The abnormal changes above were positive correlation with the degree of OSAHS . The manifested in the uvula tissue of patients with moderate and severe, contribute to descending muscle tension and ascending compliance of pharyngeal wall ,leading to upper airway occlusion observed during sleep in these patients. The histological and structural changes of the uvula have significant correlation .