Na. Blom et al., Normal development of the pulmonary veins in human embryos and formulationat a morphogenetic concept for sinus venosus defects, AM J CARD, 87(3), 2001, pp. 305-309
Citations number
21
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
A sinus venosus defect is a form of interatrial communication associated wi
th abnormal drainage of the right pulmonary veins. Its morphogenesis still
remains unclear. We therefore studied the normal development of pulmonary v
eins in human embryos in relation to the sinus venosus and the dorsal mesoc
ardium using graphic reconstructions and HNK-1 immunohistochemistry, Twenty
embryos, ranging from 4 to 7 weeks' gestation, were examined. At 4 weeks,
the orifice of the nonlumenized common pulmonary vein is visible as an endo
thelial invagination within the sinus venosus segment. Development of the m
uscular septum primum and the ventral proliferation of extracardiac mesench
yme from the dorsal mesocardium positions the common pulmonary vein (CPV) e
ventually into the left atrium, The right wall of the CPV contributes to th
e posterior part of the atrial septum and is continuous with the dorsal sin
uatrial fold (the future left venous valve). With the use of HNK-1 antigen
expression as a marker for sinus venosus myocardium, this common wall betwe
en the right-sided sinus venosus and the CPV is demonstrated, and at 7 week
s the proximal port of the right upper pulmonary vein also becomes part of
this common wall. This study demonstrates that the CPV develops within the
sinus venosus segment and that later a common myocardial wall is present be
tween the sinus venosus in the right atrium and the CPV. A deficiency of th
is wall explains the development of sinus venosus defects. (C) 2001 by Exce
rpta Medico, Inc.