Chapter 19

ANATOMY

    This is a located in varities: rare malformation where the obstruction to blood flow is the ascending aorta. There are two typical anatomical varities:

1. Membranous type where a real membrane is present in the ascending aorta.
   
2. Hypoplastic type, where a more extensive area with atrophy of the aorta and consequent reduction of the aortic lumen is responsible for the disease.
   

    The anatomical and hemodynamic events resulting from this malformation otherwise are similar to the previously described aortic valve stenosis.
    In the case of surgical treatment, cardiopulmonary bypass is necessary and a longitudinal incision is carried out on the coronary sinus of Valsalva. A prothesis of dacron, teflon or pericardium is necessary for correction of the malformation.
    In many cases supravalvular aortic stenosis forms part of a multiple malformation syndrome (multiple dental malformation, large mouth, long upper lip, full cheeks with prominent chin and typical upturned nose, mental retardation and calcium metabolism abnormalities). Bilateral multiple stenosis of the pulmonary artery branches are also frequently seen and in more than 60% of these patients with endocardial fibroelastosis of different magnitude.
    As a matter of fact, as a consequence of the high percentage of endocardial fibroelastosis, the final outcome of surgery is not as good as in the cases of aortic valvular stenosis.

SUPRAVALVULAR AORTIC STENOSIS - HYPERCALCEMIA SYNDROME

1. Hypercalcemia with normal or low alk. phosph.
2. Mental retardation
3. Alfin facies with typical dental malformations and large mouth
4. Vomiting - Anoxeria
5. Renal abnormalities

The diagram represents supravalvular aortic stenosis and consequent post stenotic dilatation.