RIGHT-VENTRICULAR OUTFLOW RECONSTRUCTION WITH CRYOPRESERVED HOMOGRAFTS IN PEDIATRIC-PATIENTS - INTERMEDIATE-TERM FOLLOW-UP WITH SERIAL ECHOCARDIOGRAPHIC ASSESSMENT

Objectives. This study was performed to assess by echocardiography the intermediate term outcome of cryopreserved homografts employed in pul monary outflow reconstruction in children and to validate the reliabil ity of Doppler echocardiography in their evaluation. Background. Cryop reserved homografts have become the most widely used pulmonary conduit s. Previous reports have shown the occurrence of homograft regurgitati on in the immediate postoperative period and the propensity of regurgi tation to progress. Although Doppler echocardiography has been useful in assessing extracardiac valved conduit stenosis, its reliability in assessing a large series of cryopreserved homografts has not been docu mented. Methods. Echocardiograms of 41 patients (43 homografts) who un derwent operations between December 1986 and October 1992 were retrosp ectively reviewed. The median age of patients at operation was 37.5 mo nths (range 3 to 333), and the median duration of follow-up was 28.5 m onths (range 1 to 68). Homograft regurgitation was classified an a sca le of 0 to 4+. Pressure gradients across the homografts measured in 23 catheterizations were correlated with corresponding echocardiographic gradients. Results. Regurgitation: Homograft regurgitation occurred i n 100% of patients at follow-up. Progression of severity > 2 grades oc curred during follow-up in 35% and was associated with operation befor e age 18 months (p < 0.002) and stenosis progression (p < 0.05) but no t with homograft type (aortic or pulmonary). These data predict that 5 0% of patients operated on before 18 months of age will have severe re gurgitation by 15 months postoperatively compared with only 15% operat ed on after 18 months. Stenosis: At follow-up, 51% of homografts had a stenotic gradient greater than or equal to 25 mm Hg predominantly at the distal anastomosis, and stenosis progression was related to young age at operation (< 18 months, p < 0.005) and small conduit size (p < 0.01). Fifty percent of conduits implanted before age 18 months could be predicted to stenose by 21.8 months compared with only 5% of those implanted after age 18 months. The gradient measured from Doppler echo cardiography correlated wed with the catheterization gradient (r = 0.8 6). Conclusions. Cryopreserved homograft dysfunction is frequent and p rogressive. Young age at operation (< 18 months) predicts more rapid d eterioration. Doppler echocardiography is reliable in assessing the sy stolic gradients across homografts. Serial echocardiographic assessmen t in the follow-up of these patients accurately characterizes these pr oblems.