An Assessment of the Surgical Results of the Site-Directed Surgical Treatment in Obstructive Sleep Apnoea Syndrome

Background: Obstructive sleep apnea (OSA) has cardiovascular, neurological, and social complications. Surgical treatment has the potential to improve airway patency but when and which surgery should be done is a controversy. Aims and objectives: To estimate the site of obstruction in patients with OSAS and to assess the surgical results of the site (of obstruction) directed surgical treatment. Methodology: Twenty patients with OSAS were included in the study with Eight adults and Twelve children. It was a prospective study. All patients were assessed for the airway collapse and surgery was done accordingly. Repeat PSG was done after surgery for success rate after 4 months of follow up. Result: 17 patients successfully completed the follow-up. Four (50%) adults and Two (17%) children have grade I or II tonsils while Four (50%) of adults and Ten (83%) children have tonsil size grade III or IV. Seven (88%) adults and one (8%) of the children have adenoid hypertrophy up to grade II. One adult (12%) and nine children (75%) have grade III Adenoid size. Two children (17%) have Adenoid grade IV size. In Four patients retropalatal more than retroglossal collapse was found (50%). One patient (12%) had retroglossal more than retropalatal collapse other one had only retropalatal collapse, and the other one had retroglossal collapse. ESS (Epworth sleepiness scale) decreased postoperatively in both groups. There is a significant change in AHI with the median pre-op AHI being 40.19 to median post-op AHI being 11.35 with a p-value 0.017. Apnea-hypopnea index (AHI) in children pre-operatively was 12.98 (median) changed to 2.15 (median) which is statistically significant. Only one adult patient (12%) is surgically cured while in five patients (63%) surgical success achieved with a surgical success rate of 5/8 (63%). Whereas only one patient is surgically cured 1/8 (13%). Eight patients achieved surgical success with a total success rate of 8/9 (89%). While only two patients achieved surgical cure (23%) among children. Conclusion: The outcome of site-directed surgical treatment is that it is a satisfactory way of treatment of OSAS with an overall success rate of 76%.

Growth and dielectric properties of Ta2O5 single crystals grown by laser heated pedestal growth technique

Ta2O5 single crystals have been grown by the laser heated pedestal growth (LHPG) technique up to several centimeters length with diameter of 1.1 mm. The crystal, characterized by X-ray diffraction, dielectric measurement, and thermal expansion analysis, has Htri-Ta2O5 symmetry. Dielectric permittivity, loss tangent along [001] and [110] direction were investigated over the temperature range from -80 ℃ to 100 ℃. Large dielectric anisotropy in Ta2O5 single crystal was observed. At room temperature, the dielectric permittivities (1 MHz) along [001] and [110] are 33.2 and 231.9, respectively. The reason of dielectric enhancement in Ta2O5 crystal grown by LHPG was also discussed.