The quantitative determination of indications for the surgical repair of cyanotic heart disease
Nakata, S.
Nihon Kyobu Geka Gakkai 34(2): 147-157
1986
ISSN/ISBN: 0369-4739 PMID: 3722911 Document Number: 280168
The operative deaths or heart failure are observed more frequently in the cases with smaller size of the pulmonary arteries. Therefore, the estimation of the pulmonary arteries becomes an important factor in the indication of surgical treatment for the congenital cyanotic heart diseases. We have proposed a quantitative method to estimate the cross-sectional areas of both pulmonary arteries, and then divided this by BSA for standardization. The resultant values were applied retrospectively to our series of total correction of various kind of diseases with decreased pulmonary flow. PA-index is based on the fact that the cross-sectional areas of the right and left pulmonary arteries increase linearly during growth. PA-index is calculated as follows; PA-index=(RPA-area+LPA-area)/BSA where, PA-area is expressed in mm2 and BSA is in square meters. The mean value of PA-index obtained from 40 patients with normally developed pulmonary artery is 330 .+-. 30, and showed constant value in a wide range of BSA from infancy to adolescence. Restrospective analysis of the preoperative PA-index carried out in 46 cases of tetralogy of Fallot, 26 cases of Rastelli operation, and 15 cases of Fontan operation. In tetralogy and Rastelli group, the PA-index ranged from 100 to 400. In Fontan group, the development of the pulmonary arteries was better than in other two group, and 70% of cases had a PA-index in the normal range. PA-index was found to be useful to predict the operative mortality, which tended to increase when PA-index was less than 100 for the conventional repair for tetralogy of Fallot, less than 200 for Rastelli procedure and less than 250 for Fontan procedure. In such patients, palliative procedures would be recommended. Severe deformities of pulmonary artery give rise to difficulty in measuring diameter in cyanotic heart disease. General principle of this PA-index is based on calculation of areas of the pulmonary arteries at their distal end where conventional angioplasty can be performed through a median sternotomy. In order to measure PA-index, it is mandatory for the pulmonary artery to be tubular. It is important to confirm that the pulmonary artery is tubular by the lateral projection. A few exceptions were found in case with major aortopulmonary collateral artery, in case after Waterston shunt and in case with prolonged preoperative pulmonary congestion which made overestimation of pulmonary arterial size.