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. MA 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 MA 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 mm(2) with a mean of 169.56 +/- 84.73 mm(2). There was no statistically significant difference of the surface area between MA types. The mean functional depth of MA 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.