Tetralogy of Fallot With Diminutive Pulmonary Arteries: Preoperative Pulmonary Valve Dilation and Transcatheter Rehabilitation of Pulmonary Arteries

Objectives. This studysoughtto determinethe results ofa novel transcatheter management approach in tetralogy of Fallot with diminutive pulmonaryarteries. Background. Tetralogy of Fallot with diminutive pulmonary arteries and severe pulmonary stenosis is rare and resembles tetralogy of Fallot with pulmonary atresia: There is a high incidence of aortopulmonary collateral channels, arborization abnormalities,stenoses and needfor multipleoperations.Because a combined catheter-surgery approach facilitates repair in these patients, such an approach may benefit those with diminutive pulmonaryarteries and pulmonary stenosis. Methods. Clinical, catheterizationand surgicaldata werestudied retrospectively for 10 such patients undergoing preoperative pulmonary valve balloon dilation, among other transcatheter interventions, from January 1989 to January 1995. Results. Initially, the Nakataindex rangedfrom 20 to 98mm1tm1 (mean 67 ± 28 mm1tm2). The pulmonary valve was first balloon dilated(mean balloon/annulus 1.5± 0.3), and the meaninitialvalve annulus Z score (-4.0 ± 1) increased to -3.3 ± 1.1 (p < 0.01). Other interventions included branch pulmonary artery balloon dilation (7patients, 23vessels) and coilembolization ofaortopulmonary collateral channels (8 patients, 31 collateral channels). At preoperativefollow- up catheterization, themeanpulmonary annulusZ score was-3.1 ± 0.7, and the Nakataindex increased to 143 ± 84mm1tm2 (p < 0.03). All patientsunderwent complete surgical repair successfully. At a meanfollow-up period of 2.6 ± 2 years,right ventricular pressurewas <70% systemic in all patients and <50% systemic in seven. Conclusions. In patients with tetralogyof Fallot, severepulmonary stenosis and diminutive pulmonary arteries, initial pulmonary n dilation increases the annulus Z score and anterograde pulmonary blood flow and facilitates simultaneous coiling of aortopulmonary collateral channels and access for branch pulmonaryartery dilation, all of which results in pulmonary artery growth, simplifying surgical management.