[Comparative value of transthoracic echocardiography and angiography for measuring the pulmonary artery annulus in tetralogy of Fallot]

Abstract

It may be necessary to perform an enlarging pulmonary annuloplasty during surgical cure of Tetralogy of Fallot (TOF) in order to optimise reconstruction of the right ventricular outflow tract. As this additional procedure implies an increase in perioperative mortality, it is useful to prepare for this eventuality before surgery. Two imaging techniques are available: transthoracic echocardiography (diameter of the pulmonary annulus obtained by averaging the measurements obtained in the subcostal and parasternal short axis views of the insertion of the pulmonary valve cusps at end systole) and selective angiography during right heart catheterisation (anteroposterior measurement with comparison to be projected and real size of the catheter at the point of insertion of the cusps at end systole). In this study, these two techniques were compared with reference to the peroperative measurement with Hegar dilators and criteria defined by Naito (minimal diameter of the pulmonary artery annulus with respect to the weight of the child). Seventy-eight children admitted to hospital between January 1986 and April 1994 for curative surgery of TOF were included. The calculation of the intra-class correlation coefficient showed a mediocre correlation with angiography and a very mediocre correlation with echocardiography compared with peroperative measurements. However, the calculation of sensitivities showed angiography to be the predictive investigation for annuloplasty in children not conforming to the Naito criteria: higher sensitivity (83% vs 26% for echocardiography), greater negative predictive value (84% vs 70%). This result holds for all categories of body weight (over and under 10 kg).(ABSTRACT TRUNCATED AT 250 WORDS)