neonatal coarctation

1. Neonatal Coarctation of Aorta

2. Introduction
• Latin term coartatio - means a drawing together
• Aortic coarctation - narrowing at some point
along the course of the aorta
• context of the congenitally malformed heart
– an area of narrowing of the thoracic aorta
– the region of the insertion of the arterial duct
– with or without additional abnormalities of the aortic
arch.

3. History in Brief
Johann Freidrich Meckel ( 1781-1833) - Prussian anatomist
18 yrs / F - Royal Academy of Sciences of Berlin -1750
‘so narrow that its diameter was smaller by half than that
of the pulmonary artery, which it should have exceeded or
at least have equalled in calibre’
Craigie (Paris) – 1789 ‘a very emaciated woman about 50 years old’.
‘ The part of the aorta which is beyond the arch, between the
ligamentum arteriosum and the first inferior intercostal, was so greatly
narrowed that it had at most the thickness of a goosequill. Hence in
taking apart its walls, which had not decreased in this place, there
remained only a small lumen. The part of the vessel which was above
the constriction was slightly dilated; the distal part was of normal
calibre. The most careful dissection did not reveal either in the aorta or
in its vicinity any cause to which this extraordinary condition could be
attributed’

4. Morphology
• Aortic coarctation - not a uniform entity
• variable degrees of hypoplasia + stenotic areas, within arch
• Tubular hypoplasia - uniform narrowing of part of the arch
• discrete coarctation - localized shelf-like lesion within the
lumen of the arch
• The extreme - interruption of the aortic arch
– Less severe- atresia of the arch - fibrous cord between the
interrupted segments - haemodynamic interruption but
anatomic continuity

5. EDWARD’s Clissification
obstructive lesion within the aortic arch- occupying preductal, paraductal, or postductal
positions

6. Obstructive Lessions
Infolding of aortic wall | Ductal Tissue Shelf

7. SHONE COMPLEX
1. “parachute” mitral valve
2. supravalvar mitral
membrane (SVMM), or
mitral ring
3. valvular and subvalvular
aortic stenosis
4. coarctation of the aorta

9. Embryology

10. Embryology ( 6th
– 8th
Week Gest.)-346
• third aortic arches persist as the common carotid arteries
• The left fourth aortic arch forms the thoracic aortic arch and isthmus
• the right fourth arch normally involutes
• Sixth Arch - proximal pulmonary arteries | Distal ductus arteriosus
A thoracic coarctation - abnormal development of left fourth and sixth aortic arches

11. Two concepts
• The Ductus tissue theory
– Migration of ductal smooth muscle cells into the periductal aorta
– Subsequent constriction and narrowing of the aortic lumen
• The Hemodynamic theory
– Hemodynamic disturbances- reduce the blood flow through the fetal aortic
arch
– Fetus aortic isthmus receives 10% of the combined ventricular output,
diameter about 70% to 80% of ascending aorta
• Coarctation in females with Turner syndrome
– fetal lymphatic obstruction - distended thoracic ducts that compress the
fetal ascending aorta

13. Different Hemodynamics in New Born
• Rapid CoA manifestation
• Myocardium lacks normal structure
• Decrease density of beta-receptor
• Poor adaptability to increase volume

15. Surgery
• End to end anatomosis ( ETE )
• Extended ETE
• Sublclavian Flap Angioplasty ( SFA )
• Subclavian tranlocation ( SFA + LSCA reimplant)
• Synthetic patch angioplasty

16. Resection and End to end anastomosis
• First reported in
1945 by Crafoord
and Nylin
• surgical treatment of
choice – discrete coa
• Extended end-to-end
anastomosis
– broader longitudinal
incision across the
proximal aorta

17. Prosthetic patch aortoplasty
• Vossschulte ( 1961 )
• Longitudinal incision
across the coarctation
• Extending onto the
proximal LSCA
• Area is enlarged with a
patch of Dacron or Gore-
Tex

18. Subclavian Flap Aortoplasty
• Waldhausen & Nahrwold - 1966
• LSCA ligated & divided
• longitudinal incision - extended
through the proximal subclavian
artery and beyond the
coarctation.
• The proximal subclavian stump
then is turned down & used as a
patch of autologous tissue
• vertebral artery is ligated