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Structural Comparison between the Right and Left Atrial Appendages Using Multidetector Computed Tomography

View Article: PubMed Central - PubMed

ABSTRACT

The three-dimensional (3D) structures of the right atrial appendage (RAA) and left atrial appendage (LAA) were compared to clarify why thrombus formation less frequently occurs in RAA than in LAA. Morphological differences between RAA and LAA of 34 formalin-preserved cadaver hearts were investigated. Molds of RAA and LAA specimens were made and the neck areas, volumes of the atrial appendages (AA), and amount of pectinate muscles (PMs) were analyzed using multidetector computed tomography. In RAA, most PMs were connected to one another and formed a “dendritic” appearance and the inner surface area was smaller than in LAA. RAA had smaller volumes and larger neck areas than LAA. The ratios of the neck area/volume were larger and the amounts of PMs were smaller in RAA than in LAA. The volumes, neck areas, and amount of PMs of RAA were significantly correlated with those of LAA. According to the 3D structure, RAA appears to be suited for a more favorable blood flow, which may explain why the thrombus formation is less common in RAA than in LAA. Examining not only LAA but also RAA by transesophageal echocardiography may be useful in high-risk patients of thrombus formation in LAA because the volume, neck area, and amount of PMs of LAA reflect the shape of RAA.

No MeSH data available.


Representative molds of the right atrial appendage (RAA) and the left atrial appendage (LAA). (a)-1 LAA was dissected from the donated body. (a)-2 A silicon mold of LAA. (a)-3 Multidetector computed tomography (MDCT) scanning image of mold of LAA. (b)-1 RAA was dissected from the donated body. (b)-2 A silicon mold of RAA. (b)-3 MDCT scanning image of mold of RAA.
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fig1: Representative molds of the right atrial appendage (RAA) and the left atrial appendage (LAA). (a)-1 LAA was dissected from the donated body. (a)-2 A silicon mold of LAA. (a)-3 Multidetector computed tomography (MDCT) scanning image of mold of LAA. (b)-1 RAA was dissected from the donated body. (b)-2 A silicon mold of RAA. (b)-3 MDCT scanning image of mold of RAA.

Mentions: AA was dissected in a manner that preserved some of the atrial wall to identify morphological differences between RAA and LAA, particularly gross anatomical differences in PMs. Then, silicon molds of AA from each heart were produced, which included a portion of the neck between RAA and LAA (silicone acrylic hybrid resin; Nissin Chemical Industry Co., Ltd., Echizen, Japan; mixing ratio of resin to hardener, 100 : 5 w/w; curing time, 7 days). The neck portion of RAA and LAA was defined as the entrance part of the AA for measurement using TEE [7, 18]. The RAA was measured in conjunction with the two parts divided by the tenia sagittalis. Each mold was inspected using MDCT of a Philips Brilliance 64-slice CT system (Royal Philips, Amsterdam, Netherlands). CT scanning protocols: tube voltage, 120 kVp; tube current, 50 mA; detector configuration, 64-row detectors with 0.625 mm section thickness; beam collimation, 40 mm; rotation time, 0.5 s; pitch, 0.515; display field of view, 16 cm; imaging filter, C-types (Figure 1).


Structural Comparison between the Right and Left Atrial Appendages Using Multidetector Computed Tomography
Representative molds of the right atrial appendage (RAA) and the left atrial appendage (LAA). (a)-1 LAA was dissected from the donated body. (a)-2 A silicon mold of LAA. (a)-3 Multidetector computed tomography (MDCT) scanning image of mold of LAA. (b)-1 RAA was dissected from the donated body. (b)-2 A silicon mold of RAA. (b)-3 MDCT scanning image of mold of RAA.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC5120179&req=5

fig1: Representative molds of the right atrial appendage (RAA) and the left atrial appendage (LAA). (a)-1 LAA was dissected from the donated body. (a)-2 A silicon mold of LAA. (a)-3 Multidetector computed tomography (MDCT) scanning image of mold of LAA. (b)-1 RAA was dissected from the donated body. (b)-2 A silicon mold of RAA. (b)-3 MDCT scanning image of mold of RAA.
Mentions: AA was dissected in a manner that preserved some of the atrial wall to identify morphological differences between RAA and LAA, particularly gross anatomical differences in PMs. Then, silicon molds of AA from each heart were produced, which included a portion of the neck between RAA and LAA (silicone acrylic hybrid resin; Nissin Chemical Industry Co., Ltd., Echizen, Japan; mixing ratio of resin to hardener, 100 : 5 w/w; curing time, 7 days). The neck portion of RAA and LAA was defined as the entrance part of the AA for measurement using TEE [7, 18]. The RAA was measured in conjunction with the two parts divided by the tenia sagittalis. Each mold was inspected using MDCT of a Philips Brilliance 64-slice CT system (Royal Philips, Amsterdam, Netherlands). CT scanning protocols: tube voltage, 120 kVp; tube current, 50 mA; detector configuration, 64-row detectors with 0.625 mm section thickness; beam collimation, 40 mm; rotation time, 0.5 s; pitch, 0.515; display field of view, 16 cm; imaging filter, C-types (Figure 1).

View Article: PubMed Central - PubMed

ABSTRACT

The three-dimensional (3D) structures of the right atrial appendage (RAA) and left atrial appendage (LAA) were compared to clarify why thrombus formation less frequently occurs in RAA than in LAA. Morphological differences between RAA and LAA of 34 formalin-preserved cadaver hearts were investigated. Molds of RAA and LAA specimens were made and the neck areas, volumes of the atrial appendages (AA), and amount of pectinate muscles (PMs) were analyzed using multidetector computed tomography. In RAA, most PMs were connected to one another and formed a “dendritic” appearance and the inner surface area was smaller than in LAA. RAA had smaller volumes and larger neck areas than LAA. The ratios of the neck area/volume were larger and the amounts of PMs were smaller in RAA than in LAA. The volumes, neck areas, and amount of PMs of RAA were significantly correlated with those of LAA. According to the 3D structure, RAA appears to be suited for a more favorable blood flow, which may explain why the thrombus formation is less common in RAA than in LAA. Examining not only LAA but also RAA by transesophageal echocardiography may be useful in high-risk patients of thrombus formation in LAA because the volume, neck area, and amount of PMs of LAA reflect the shape of RAA.

No MeSH data available.