A 6-month-old child with worsening cyanosis from birth, hypercyanotic spells and failure to thrive, was admitted with severe desaturation. Systemic saturation was < 56%, and echocardiography revealed severe infundibular pulmonary stenosis with normal pulmonary valve and a restrictive ventricular septal defect. The child underwent percutaneous stenting of the right ventricular outflow tract (RVOT), with good reduction in gradient and clinical stabilization. The child is being followed up for elective intracardiac repair.

       Case Report. A 6-month-old child was admitted with cyanosis noted from birth with failure

Figure 1

Right ventricular angiogram showing restrictive VSD with right-to-left shunting.

to thrive, cyanotic spells and worsening cyanosis. The child weighed 4.5 kg, had severe systemic desaturation (< 56%) and was tachypneic at rest. Clinical examination revealed a soft pulmonary component of the second heart sound, a grade-4 ejection systolic murmur at the left sternal border and right ventricular apical impulse.
       Electrocardiography showed sinus tachycardia, right ventricular hypertrophy with strain and small left ventricular forces. Echocardiography revealed severe infundibular pulmonary stenosis (PS) with no valvular component, restrictive perimembranous ventricular septal defect (VSD) with aortic override, right ventricular (RV) hypertrophy and dysfunction. The pulmonary stenosis gradient was 110 mmHg and the branch pulmonary arteries were normal.
       In view of the child’s unstable clinical condition, systemic-to-pulmonary artery shunt was an option, but due to the restrictive closing VSD and RV dysfunction, relieving the RVOT obstruction was necessary. The child’s parents, however, were unwilling to allow intracardiac repair at this stage, hence the child underwent palliative stenting of the RVOT to abolish the gradient.

Figure 2

Left ventricular angiogram showing small compressed left ventricle.

       Cardiac catheterization confirmed the diagnosis as tetrology of Fallot with restrictive VSD and purely infundibular PS (Figures 1 and 2).

Catheterization revealed the following data:

RV: 124/0–12 mmHg
Systemic saturation = 54%
PA: 12/8, mean = 11 mmHg; PS gradient = 112 mmHg
LV: 70/0–8 mmHg;
Aorta: 66/49 mmHg
The RVOT was crossed with a 0.018-inch Roadrunner^® wire (Cook, Inc., Bloomington, Indiana) and the RVOT was stented with a 8 x 17 mm Express™ peripheral stent (Boston Scientific, Natick, Massachusetts) (Figures 3 and 4). The stent was postdilated with 10 x 20 mm Stricker balloon.

Post-stenting catheterization data were as follows:

RV: 24/0–8 mmHg
Systemic saturation = 98%
PA: 20/8; mean = 13 mmHg
PS gradient = nil
LV: 90/0–8 mmHg
Aorta: 90/42 mmHg

       The left ventricle, which was under filled prior to the procedure, was well filled post-stenting (Figures 2 and 5).

       Discussion. The indications for RVOT stenting are RV-to-PA conduit stenosis, residual infundibular stenosis after intracardiac repair, tetrology of Fallot with hypoplastic branch pulmonary arteries

Figure 3

Stent positioned across the RVOT.

after palliative shunt surgery, pulmonary atresia after perforation of atretic segment, and RV hypertrophic cardiomyopathy.^1,2 RVOT stenting is superior to plain balloon dilatation alone due to incomplete abolition of gradients, a high incidence of restenosis and precipitation of hypoxicspells.³ Treatment of choice in native infundibular stenosis is surgery, as it carries a very low risk and rarely requires reoperation.
       RVOT stenting provides an effective alternative to palliative surgical enlargement of the RVOT. Restenosis causes recurrence of gradients in some cases, but responds to redilatation.² Complications of RVOT stenting are stent migration, ventricular arrhythmias, collapse or fracture of the stent and recurrent stenosis.² In properly selected cases, RVOT stenting can be used as a

Figure 4

Right ventricular angiogram post-stenting.

Figure 5

Left ventricular angiogram post-stenting.

palliative procedure with gratifying results, as occurred in our case. RVOT stenting is usually indicated in cases where total intracardiac repair is not possible. In our case, due to the underweight child having severe desaturation and the parents’ unwillingness to allow open heart surgery, we carried out the percutaneous intervention.
       During the 6-month follow-up period, repeat angiography was performed, showing no stent migration, restenosis or fracture. The child is scheduled for total intracardiac repair soon, and the surgeons do not anticipate problems in cutting across the stent to widen the RVOT.

1 Hausdorf G, Schulze-Neick I, Lange PE. Radiofrequency-assisted “reconstruction” of the right ventricular outflow tract in muscular pulmonary atresia with ventricular septal defect. Br Heart J 1993;69:343–346.
2 Gibbs JL, Uzun O, Blackburn MEC, et al. Right ventricular outflow stent implantation: an alternative to palliative surgical relief of infundibular pulmonary stenosis. Heart 1997;77:176–179.
3 Nakanishi T. Intavascular stents for management of pulmonary artery and right ventricular outflow obstruction. Heart Vessels 1994;9:40–48.