A Study on Growth of Pulmonary Artery after Modified Blalock-Taussig Shunt in Tetralogy of Fallot

Fallot 4 징증에서 변형 Blalock Taussig 수술후 폐동맥성장에 관한 연구

Ten patients with tetralogy of Fallot were studied angiocardiographically before a modified Blalock-Taussig shunt and again 25*3.2 months after the previous shunt. All of ten patients had patent previous shunt at the time of follow up examination. Pre-and postoperative diameters of left and right pulmonary artery and descending aorta were measured and pulmonary artery index [the sum of the crossectional areas of the right and left pulmonary arteries standardized by the body surface area] was calculated. The ratio of mean diameter of left and right pulmonary arteries to the diameter of the descending aorta [LPA+RPA/2xDA] was increased postoperatively by 0.20*0.068 [p=0.020]. Mean PAI [pulmonary artery index] increased from 283.8*178.4 mm/m2 BSA to 345.8~144.5 mm/m2 BSA after shunt operation [p=0.019]. This results suggested that the modified Blalock-Taussig shunt was effective to help growth of the pulmonary arteries in most cases of the study populations but the ones with the PAI>233mm*/m* BSA appeared less benefited by Blalock Taussig shunt. Calculation of PAI could be an aid to making a decision whether to perform a one stage corrective surgical procedure or a palliative shunt procedure in the patient with small pulmonary arteries.