vascular variation Flashcards
how does development of the heart and vascular system begin?
begins early in development in the mesoderm w/in (embryonic) and outside (extra embryonic, yolk sac and placental) the embryo
in early development how many aorta are there?
4:
2 dorsal aortae
2 ventral aortae
explain development of the venous system
embryological development of the venous system is complex
early in development vitalise veins (which drain the yolk sac) and umbilical veins form
what are the veins above the heart called?
pre cardinal veins (bilateral anterior veins)
- lee et al 2010
what are the veins below the heart called?
post cardinal veins (bilateral posterior veins)
- lee et al 2010
explain the developmental process of many veins that are singular in the adult
many veins that are singular in an adult go through a developmental process that involves the development of bilateral vessels first and then one regresses to leave the adult for
explain the development of the superior vena cava
the right cardinal veins form the superior vena cava
the left anterior cardinal vein should regress
what happens if the left anterior cardinal vein does not regress?
then there are 2 SVCs (duplication of the SVC)
what is the incidence of duplicated SVC?
very rare
explain the implication of a duplicated SVC
usually asymptomatic
venous variations are often asymptomatic because as long as the area is being drained and into the correct vessel then there are no blood flow issues and so no symptoms
explain the role of the 2 dorsal aortae in development
they communicate w/ the developing aortic sac and trunkus arterioles via 6 embryonic arches before the most posterior parts of the dorsal aortae fuse together to form one descending aorta
what doe the 4th embryonic arch from the dorsal aorta form?
the adult arch of the aorta on the left side
the right subclavian on the right side
what is chromosome 22q11 deletion assoc w/ and what is the reference?
chromosome 22q11 deletion is assoc w/ congenital heart disease but also w/ isolated conotrunchal anomalies
momma et al 1999
what were the findings of momma et al 1999?
that there is lots of variant anatomy possible when chromosome 22q11 is deleted but the heart retains normal textbook anatomy
where does the brachiocephalic artery form?
from the right horn of the aortic arch
what is the incidence of brachiocephalic artery variation?
it is rare
explain the study carried out by Iterezote et al (2009) on the branchiocephalic artery
study on 110 cadavers found 1 anomaly in the brachiocephalic trunk (0.9%)
the anomaly was brachiocephalic trunk 3.4cm long and 1.9cm in diameter lying infront of the trachea
explain the study carried out by Cromer et al (2004) on the brachiocephalic artery
highlighting the same variant as Iterezote et al (2009) but to the left of the aorta
lead to serious haemorrhage during percutaneous tracheotomy
67y/o female cadaver
what study discussed anomalous vessel compression and what were the findings?
De-Giogio et al (2011)
40y/o male, sudden death
anomalous origin of the right coronary artery lead to massive aneurysm that eventually burst and caused the death of the pt
where is the right coronary artery meant to originate from?
from the R aortic sinus
where did the right coronary artery arise from in the 40y/o male who died suddenly in De-Giorgio et al (2011)?
from the L aortic sinus and passed between the aortic and pulmonary valves
why did the origin of the right coronary artery cause the death of the 40y/o man in De-Giorgio et al (2011)?
because it passed between the aortic and pulmonary valves meaning it was compressed by the expansion of the valves and altered the haemodynamics leading to the formation of an aneurysm
why are variations of the IVC more common than variations of the SVC?
because the developmental process of the IVC is more complex than that of the SVC