[II-TISL-01] 修正大血管転位症の解剖学
Keywords:Congenitally Corrected Transposition of The Great Arteries, discordant atrioventricular and ventriculo-arterial connections, Morphology
CCTGA is a complex congenital anomaly with a wide spectrum of morphological features and clinical profiles. The underlyingmalformation is the combination of discordant atrioventricular and ventriculo-arterial connections (“duplicated discordance”), results in normal physiology despite the presence of the transposition of the great arteries. The most common anatomical arrangement is situs solitus with L-looping of the ventricles and the aorta anterior and leftward of the pulmonary artery (S,L,L) in 95 percent of caseswhile situs inversus with D-looping of the ventricles and the aorta anterior and rightward (I,D,D) is also seen in the other 5% of ccTGA cases. The majority of cases have any associated anatomical abnormalities (ie VSD in 60 to 80 % of patients, LVOTO or PS/PA in 40 to 50%, and abnormalities of the tricuspid valve in up to 90% with Ebstein’s anomaly in 50%. The isolated ccTGA without malformation is seen 1% of cases. Due to the malalignment of the atrial and inlet ventricular septum with the reversed off-setting of the attachments of the leaflets of the atrioventricular valves to the septum, the regular atrioventricular node is anatomically impossible to connect to the atrioventricular bundle in ccTGA with situs soitus {SLL} arrangement andthe anterior AV node is located above the lateral margin of the area of pulmonary to mitral fibrous continuity which gives rise to a penetrating bundle (PB) and the non-branching bundle (NBB) encircles pulmonary valve anteriorly and descends onto the anterior part of the trabecular septum on the right side (morphological LV) surface of the septum.