RISK FACTORS : Turner syndrome, Congenital left heart abnormalities, Family history of left ventricular outflow tract obstruction
Medical Care:
" Severe coarctation of the aorta
o Neonates with severe coarctation of the aorta should first have their condition stabilized.
o First, support respiratory collapse with intubation. Second, infuse prostaglandin E1 to open the ductus arteriosus. Third, correct acidosis. Finally, provide inotropic support to improve symptoms of congestive heart failure.
" Less severe coarctation of the aorta
o Patients presenting with less severe coarctation of the aorta beyond the neonatal period usually have chronically increased afterload and show signs of congestive heart failure. These patients should be treated with digoxin and diuretics.
o Attempts should be made to postpone intervention, such as surgery or balloon dilatation, until the patient is hemodynamically stable.
Surgical Care: No single technique is superior to others in minimizing the rate of restenosis. The preferred method depends on anatomy of the lesion and institutional experience.
" Indication for intervention: At present, 3 specific indications exist for intervention in patients with coarctation of the aorta.
o Significant coarctation or recoarctation of the aorta with long-standing hypertension with or without symptoms
o Hemodynamically significant aortic stenosis
o Female patient contemplating pregnancy
" Types of surgery
o In 1944, Blalock and Park performed the first experimental surgical repair of coarctation of the aorta in animals, which involved use of the left common carotid or subclavian artery to bypass the coarctation with end-to-end anastomosis.
o Resection of the coarctation site and end-to-end anastomosis to repair coarctation was performed first on humans in 1944 by Crafoord, Nylin, Gross, and Hufagel. This is the preferred surgical method even today. In this technique, the aorta is cross-clamped above and below the obstruction, and the discrete narrowing is resected. The advantage of this procedure is that the obstructed site is completely resected. It also avoids the use of prosthetic material and maintains a functioning left subclavian artery. The disadvantages of this procedure involve the sacrifice of spinal and intercostal vessels resulting in paralysis. Also, a high rate of restenosis exists with use of continuous running suture or circumferential fibrosis. This problem is overcome by use of interrupted and absorbable sutures, which allows for improved growth of the anastomotic site.
o Patch aortoplasty was first performed by Vossculte in 1961 to repair coarctation of the aorta. This technique involves cutting across the obstruction and augmenting the area with a patch of prosthetic material. The advantages of this procedure include the ability to repair a long segment of coarctation; sparing of the left subclavian, intercostal, and spinal arteries; and preserving native aortic tissue to allow for growth. The disadvantage of this procedure is that it uses prosthetic material, which may gradually result in aneurysm formation.
o Left subclavian flap angioplasty, introduced in 1966 by Waldhausen and Nahrwold, involves ligating the left subclavian artery and dividing it distally. A longitudinal incision is made from the descending aorta to the coarctation superiorly into the origin of the left subclavian artery. The subclavian artery is turned down and used to enlarge the narrowing. To prevent subclavian steal phenomena, the vertebral artery is ligated. The advantages to this procedure include preservation of native vascular tissue and avoidance of circumferential sutures, which allows for better growth of the involved area. The disadvantage to this procedure is the sacrifice of a major artery to the left arm, resulting in poor growth of that extremity.
o Bypass graft repair bridges the ascending and descending aorta. The major disadvantage of this procedure is that prosthetic material does not grow as the child grows, and it becomes calcified and narrow with time.
o Catheter-based intervention consists of primary ballooning and/or stenting and rapidly is becoming an accepted form of management of native coarctation. Ballooning and stenting is emerging as the treatment of choice for residual or recurrent stenosis. Most cardiologists who treat adults with congenital cardiovascular defects prefer catheter-based intervention. The unacceptably high incidence of paralysis makes surgical intervention on the adult patient much less desirable.
Activity: As with all aortopathies and aortic valve problems, significant and prolonged isometric activities are contraindicated. The risk of dissection, even in repaired coarctation, remains significant and may be increased with isometric activity.
DRUG(S) OF CHOICE :
β’ Alprostadil (prostaglandin E1), patency of ductus arteriosus
β’ Antibiotic prophylaxis (for dental and/or invasive procedures) for life (even after correction)
β’ Antihypertensives if needed
β’ Preload and afterload reduction if heart failure develops
PATIENT MONITORING Frequent :
postoperative followup for evidence of re-stenosis (check for hypertension and pulse disparities) and late
complications
PREVENTION/AVOIDANCE: Patients should be encouraged to have normal lifestyles and activities after coarctation correction
POSSIBLE COMPLICATIONS:
β’ Most common with late or no correction
β’ Heart failure
β’ Aneurysm of circle of Willis, rupture possible
β’ Hypertension
β’ Rupture or dissection of aortic aneurysm
β’ Endarteritis or endocarditis (need antibiotic prophylaxis)
β’ Aortic valve disease (stenosis or insuffi ciency)
β’ Post coarctectomy syndrome: recurrence, hypertension, atherosclerotic heart disease, aneurysm at site of coarctectomy, progressive aortic stenosis and/or regurgitation
β’ Fistula formation between aorta and airways leading to hemoptysis
EXPECTED COURSE/PROGNOSIS :
β’ Depends on age of repair and presence of other cardiac abnormalities
β’ Residual or restenosis (6-33%)
β’ Subsequent cardiac surgery (11%)
β’ Hypertension (25%)
β’ Survival after surgery: 10 years (91%), 20 years (84%), 30 years (72%)
β’ Uncorrected, 80% mortality before age 50