Morphometric study of the left atrial appendage related to closure device deployment: a cadaveric study in Thai population.

BACKGROUND: This study aims to investigate the left atrial appendage (LAA) regarding external morphology, positional relation of the ostium of LAA to the left superior pulmonary vein (LSPV), ostium shape, ostium diameter and functional depth. MATERIALS AND METHODS: Left atrial appendages of 65 cadaveric hearts were examined. RESULTS: The prevalence of Cauliflower, Windsock, Cactus and Chicken wing type of LAA were 27.7%, 27.7%, 26.1%, and 18.5%, respectively. LAA with two lobes was the most common. All specimens showed no accessory LAA. The relation of the ostium to the LSPV was found in two types which were mid-type (LAA ostium was at the same level as LSPV) in 29 (44.6%) cases and inferior type (LAA ostium was below the level of LSPV) in 36 (55.4%) cases. The shapes of LAA ostium were oval and round with a prevalence of 55.4% and 44.6%, respectively. The diameter of round type ranged from 9.53 to 21.51 mm with a mean of 14.56 ± 2.6 mm. While in oval type, the long and short diameters ranged from 11.61 to 31.71 mm with a mean of 14.23 ± 4.2 mm and from 6.70 to 23.90 mm with a mean of 11.66 ± 3.5 mm, respectively. The Surface area of the ostium was calculated from the ostium diameter, range from 71.29 to 594.92 mm2 with a mean of 169.56 ± 84.73 mm2. There was no statistically significant difference of the surface area between LAA types. The mean functional depth of LAA was 11.57 ± 4.43 mm. The functional depth of the Windsock-type appeared to be statistically significant from the others. However, there was no correlation between the functional depth and the ostium surface area. CONCLUSIONS: This morphometric data might be beneficial for deployment of LAA closure device in the Thai population.

[Dimensional change of elastomeric impressions after disinfectant immersion].

One method to prevent cross-contamination in dental clinic is to immerse the impressions in disinfectants before making master models. This study to evaluate the effect of disinfectants on dimensions of the elastomers namely polyether, condensation silicone, addition silicone and polysulfide, the disinfectant used in this study is 1% Sodium hypochlorite, 0.13% Sporicidin and 10% Gigasept. Being left under room temperature and immersed in distilled water are two types of controls. Dimensional changes can be measured on master model and compared with the brass standard model. The study reveals that the three disinfectants have no effect on vertical dimensions of all four elastomers but have statistically effect on horizontal dimensions of only polyether (p less than .05). It concludes that all the elastomeric impressions except polyether should be immersed in disinfectants before making master models.