Venous anomalies Flashcards
Clinical significance of venous anomalies
→ Rarely clinically significant
Embryology of venous system: embryonic venous system
- Earliest form of venous return to embryonic heart
o Paired cardinal venous system: cranial and caudal cardinal veins
o Join sinus venosus
What forms CrVC? Which parts of the embryologic system regresses
o L cranial cardinal vein regresses → anastomosis to R cranial cardinal vein
o R cranial and common cardinal veins remain and enlarge → form CrVC
What forms from L common cardinal vein persists
→ form coronary sinus
Drain coronary circulation
Supracardinal system and species differences
o R supracardinal vein form R azygos (Hu, dog, cats, horses)
o Absent in swines and cattles → will have hemiazygos on L side formed by L supracardinal vein
o Azygos (R) or hemiazygos (L) depending on species
Join proximal segment of corresponding R or L CrVC
Which species normally have L CrVC
Rabbits/rats/mice
Which species normally have L azygos
Po
Which species normally have R azygos
Ca/Fe
Which species normally have R and L azygos
Bo
Breed reported for pLCrVC
German Shepherds
From which structure coronary sinus is a remnant
embryonic L Cr cardinal vein
Features of pLCrVC
o Can be single CrVC or both L and R CrVC present
o Can be associated with other congenital diseases (TOF, ASD, mitral atresia, juxtaposition of RA appendage)
o Should not be ligated → appropriately return venous blood to RA
Not clinically significant hemodynamically
o Size is iα to co existent R CrVC
Types of pLCrVC described by buchanan
o Complete → enter CS
Receive blood from veins cranial to the heart
o Incomplete → L azygos drain into it before entering CS
Proximal portion of L CrVC receives vein draining the costocervical-vertebral trunk
In Hu, pLCrVC can be associated w/
unroofed CS
If so, persistent L CrVC drain into LA
R to L shunting → cyanosis