Echocardiographic evaluation of the ductal morphology in patients with refractoriness to lipo-prostaglandin E1 therapy

Abstract

Lipo-prostaglandin (PG)E1 is effective at lower doses and has fewer side effects than PGE1-cyclodextrin (CD). Previous studies, however, have suggested that some patients show refractoriness to lipo-PGE1 in the course of treatment. The present paper examines: (i) whether such cases can be predicted by examining the ductal morphology before and 24 h after the start of lipo-PGE1 infusion; and (ii) whether PGE1-CD dilates the ductus arteriosus in patients with refractoriness to lipo-PGE1. The ductal morphology was evaluated with two echo indices, such as minimal and minimal plus maximal intraluminal diameters of the ductus. Two-dimensional echocardiography was performed in 24 patients with ductus-dependent congenital heart disease. The two echo indices were measured before and 24 h after lipo-PGE1 infusion and also at least twice per week until surgery. In 19 of 24 patients, ductal patency was maintained until surgical treatment (group A). The remaining five patients (21%) showed ductal closure during the course of the lipo-PGE1 therapy (group B). There were no significant differences between the two groups, in either the maximal or minimal diameters, which were examined before and 24 h after treatment. In the five patients of group B, lipo-PGE1 was replaced with a relatively high dosage of PGE1-CD (50-100 ng/kg per min), resulting in good ductal patency until surgery. Patients with refractoriness to lipo-PGE1 therapy could not be predicted from initial intraluminal diameters of the ductus using echocardiography. Therefore, serial echocardiographic examinations are important to detect early findings of ductal closure. In addition, PGE1-CD is still useful as back-up therapy in such patients.