Ductus arteriosus arise
from the left 6th aortic arch.
Ductus closes
physiologicallt within 2 hours of birth.
Ductus anatomically
closes by 2 weeks.
Closure of ductus can
take upto 8 weeks in term infants and upto 6 months in preterm infants.
Why does the ductus closes
after birth?
1.Ductus artenosus closes
immediately after birth due to sudden increase in partial pressure of oxygen.
2.Decreased level of
vasoactive prostaglandins.
What are the ductus
dependent circulations
In certain situations
ductus artenosus is the source of pulmonary blood flow. They include
- Pulmonary atresia with intact inter ventricular septum.
- Ductus is the only source of systemic blood flow.
- Hypoplastic left heart syndrome.
- Aortic atresia.
- Complete interruption of aortic arch.
- Preductal coarctation of aorta.
Ductus as the site of
bidirectional mixing of blood seen in TGA (Transposition of great arterires)
