Anatomy of the ventricular septal defect in outflow tract defects: Similarities and differences

Abstract

The ventricular septal defect in outflow tract defects is always an outlet ventricular septal defect, cradled between the 2 limbs of the septal band. However, there are some differences regarding the posteroinferior and superior rims of the ventricular septal defect. These differences suggest an anatomic continuum from the isolated outlet ventricular septal defect to the interrupted aortic arch type B rather than distinct physiologic phenotypes, related to various degrees of abnormal rotation of the outflow tract during heart development: minimal in isolated outlet ventricular septal defect; incomplete in tetralogy of Fallot, tetralogy of Fallot with pulmonary atresia, and double outlet right ventricle; absent in common arterial trunk; and excessive in interrupted aortic arch type B.

A new anatomic approach of the ventricular septal defect in the interruption of the aortic arch

“…We demonstrated in an earlier anatomic study that the VSD in cardiac neural crest defects is always an outlet VSD (Mostefa‐Kara et al. ), which can be easily explained by embryology.…”

“…This VSD is different from the malalignment outlet VSD with a fibrous postero‐inferior rim because of its geographical location, but also because the fibrous continuity involves the septal leaflet of the tricuspid valve and not the anterior leaflet, contrary to the outlet VSD (Mostefa‐Kara et al. ).…”

“…An outlet VSD was defined as a VSD opening to the outlet of the right ventricle and located between the two limbs of the septal band (Mostefa‐Kara et al. ). There were some variations observed, especially regarding the postero‐inferior rim of the VSD, which can be fibrous (with fibrous continuity between the aortic and the anterior leaflet of the tricuspid valve) or muscular, due to a fusion between the posterior limb of the septal band and the ventriculo‐infundibular fold.…”

Impact of anatomic characteristics and initial biventricular surgical strategy on outcomes in various forms of double-outlet right ventricle

“…We include in this category all the VSDs that are not located between the 2 limbs of the septal band, that is inlet, muscular, and central membranous VSD. 12 Associated cardiac anomalies were noted: VSD (location, number, and restriction when significant pressure gradient between the ventricles was diagnosed), subpulmonary and subaortic obstruction, atrioventricular septal defect (AVSD), mitral valve cleft and other mitral valve anomalies, straddling of the mitral or of the tricuspid valve, and coronary artery anomalies.…”

“…Although Brown and colleagues 16 reported biventricular repair in a high proportion of DORV with ncVSD, the choice of this approach as opposed to a univentricular palliation program should be carefully analyzed, because the risk of death and reoperation remains high. The distance between the VSD and the great arteries, 14 the location of the VSD (inlet, muscular, or central perimembranous), 12 and the evaluation of the outflow tracts, AV valves, and global anatomy are the main parameters that should be analyzed to indicate a biventricular repair or a univentricular strategy in DORV with ncVSD. Redirecting the ncVSD to the unobstructed RVOT associated with the ASO procedure, performed in 5 cases in our series, appeared to be a valuable alternative in this unfavorable anatomic subset.…”