Doppler flow evaluation can anticipate abnormal left lung perfusion after transcatheter closure of patent ductus arteriosus.

Abstract

Coil protrusion into the left pulmonary artery (LPA) has been described after transcatheter closure of the patent ductus arteriosus (PDA). The possible impact of such a finding in lung perfusion has not been completely clarified. We evaluated Doppler flow velocities and lung perfusion in patients submitted to that procedure. After transcatheter closure of PDA with coils, 70 patients (mean age 8.6+/-3.4 years) were followed for a period of 3.6+/-0.9 years (range 2.1-5.9) and compared to 22 controls. Peak flow velocities and coil protrusion were assessed by Doppler echocardiography. A Doppler velocity index (DVI) was calculated by the difference between the LPA and right pulmonary artery (RPA) peak flow velocities relative to the pulmonary trunk (PT) expressed in percentage, as follows: DVI=(LPA velocity - RPA velocity)/PT velocity x 100. Lung scintigraphy was performed using (99m)Tc-labelled macro-aggregated albumin. Device protrusion was observed in 94% of the patients, 10% of whom presented abnormal left lung perfusion. Peak LPA velocity and DVI were significantly greater in patients (p=0.001) and correlated negatively with left lung perfusion values (R(2)=0.21 and R(2)=0.65, respectively). A cut-off value of 50% for the DVI showed high sensitivity and specificity for reduced lung perfusion. Impaired left lung perfusion may appear following transcatheter closure of PDA with coils and the determination of DVI may anticipate such alteration.