Coarctation of Aorta

Last updated 2015 - Written by Dr. Benjamin Marsh

Definition

Coarctation is a stricture of the descending aorta near the insertion site of the ductus arteriosis, ductal COA are most common.

Coarct 1.JPG

Symptomatic COA typically presents in the neonatal period because of  reduced antegrade flow due to concomitant aortic hypoplasia, VSD, PDA or mitral valve defects. They are physiologically different from the asymptomatic types that develop compensatory collateral circulation and often do not present in childhood.

Clinical Manifestations of Symptomatic

  • Presentation: poor feeding, FTT and dypnea (CHF), oliguria, anuria (renal failure) and circulatory chock at 2-6wks. Most are hospitalized by 14d.
  • PE:  There is usually a loud gallop, pulses are often weak and thready.
  • EKG: RVH or RBBB is usually present (LVH is typically absent as there has been insufficient time to compensate).
  • CXR: shows cardiomegaly, pulmonary edema or pulmonary venous congestion.
  • Echo is diagnostic.

Clinical Manifestations of Asymptomatic

  • Rarely complain of leg pain. Natural Hx includes LV failure, ICH, or HTN encephalopathy by adulthood.
  • PE: Absent or weak and delayed leg pulses. Arm HTN may be present. A grade 2-3/6 late SEM continuing past S2 heard best at left interscapular but also URSB and MLSB. Often an ejection click from a bicuspid valve is present at the apex.
  • EKG: LVH (without S-T or T wave changes) or WNL.
  • CXR: May show a slightly enlarged heart, a prominent aortic knob, and a “3” sign on overpenetrated films may be seen. May see rib notching in pt over 10yo from collaterals.
  • Echo is diagnostic. Coexistence of a PDA makes the diagnosis of a COA difficult, and a isthmus/descending aorta diameter <0.64 strongly suggest COA

Management of Symptomatic Types

  • Vasopressors, diuretics, and oxygen are used for CHF, and  PGE 1 infusion is given to reopen the ductus. Intubation reduces O2 demand.
  • Balloon angioplasty is occasionally used in sick infants, but because of high complication rate (recoarctation in >50% and femoral artery injury) surgery is preferred.
  • Surgery:

The mortality rate for isolated COA is less than 5%. Postoperative renal failure is the most common cause of death. Residual obstruction or recoarctation occurs in 33%.

If there is a coincidental non-restrictive VSD, it will need to be repaired during surgery.

If there is a coincidental VSD and PA pressures remain high after repairing the COA, then PA banding is indicated with later VSD repair at 6-24mo.

A restrictive VSD will usually be managed expectantly.

Management of Asymptomatic Types

Treat HTN, with high suspicion of hypertensive crisis.

Surgery is superior to ballon angiopathy, but expandable stents are available.

If severe HTN, CHF, or cardiomegaly is present, surgery is indicated. If the diameter of the coarct is <50% of the aorta then surgery is indicated. A pressure gradient≥20 mm Hg between UE and LE is an indication for elective surgery at age of 1 to 2 yo . This degree of pressure gradient corresponds to a 65% reduction in aortic diameter. 

Post op

Follow up continues indefinitely.

Symptomatic

Because recoarcation is so frequent pt are to get f/u every 6-12mo. Balloon angioplasty may be used in these cases. Close monitoring of blood pressures for HTN

Asymptomatic

Post-op HTN and abd pain without residual gradient are common and are managed with nitroprusside and esmolol (switched later to captopril or enalapril)

Residual pressure gradient of < 10 to 20 mm Hg is common. Monitor for HTN and recoartation. Watch for bicuspid aortic valve, mitral valve disease or subaortic AS.

Sources: Park Ch 3,   Nadas’ Ch 36,     Nelsons Ch 421