F. Godart et al., EARLY AND LATE RESULTS AND THE EFFECTS ON PULMONARY-ARTERIES OF BALLOON DILATATION OF THE RIGHT-VENTRICULAR OUTFLOW TRACT IN TETRALOGY OF FALLOT, European heart journal, 19(4), 1998, pp. 595-600
Background Balloon dilatation of the pulmonary valve remains controver
sial as a palliative procedure in tetralogy of Fallot. Aims To determi
ne the clinical outcome, growth of the pulmonary Vascular tree and End
ings at surgery of balloon dilatation of the pulmonary valve performed
as a palliation in infants with tetralogy of Fallot. Methods and Resu
lts Thirty-three severely cyanosed infants (mean age of 3 months for t
he whole population, including seven neonates) underwent this procedur
e from June 1990 to January 1997. After balloon dilatation, systemic o
xygen saturation increased from a mean value of 76 +/- 9% to 88 +/- 7%
(P<0.001). The procedure was accomplished without complications. Four
patients had recurrent hypoxic spells after dilatation leading to sur
gical repair within 30 days of dilatation (three modified Blalock-Taus
sig shunts and one complete repair). A control study was performed at
a mean of 6.1 +/- 4.5 months after dilatation in 16 patients to establ
ish growth of the pulmonary vascular tree (repeat catheterization in n
ine patients and surgical pulmonary annulus calibration in seven). The
pulmonary annulus increased from a mean Z score of -4.1 +/- 0.9 SD to
-2.5 +/- 1.1 SD (P<0.001), Z score for the right pulmonary artery fro
m -3.0 +/- 0.6 SD to -1.9 +/- 1.2 SD (P=0.007) and the Z score for the
left pulmonary artery from -2.7 +/- 0.7 SD to -1.6 +/- 1.3 SD (P=0.02
1). At late follow-up (mean of 9 months after dilatation, range 3 to 5
4 months), 28 patients underwent complete repair. Trans-annular patchi
ng was required in 43% of patients. Four post-operative deaths were ob
served, none dilatation related. Conclusion Balloon dilatation of the
pulmonary valve is an effective and safe palliation in tetralogy of Fa
llot. It promotes growth of the pulmonary vascular tree, reducing the
need for trans-annular patching and is recommended in symptomatic infa
nts of very young age, with a small pulmonary annulus (Z value below -
4 SD) and associated cardiac anomaly.