Stenting of the Right Ventricular Outflow Tract in the High-Risk Infant With Cyanotic Teratology of Fallot

Abstract

Neonatal tetralogy of Fallot (TOF) repair carries an increased risk of low birthweight or premature infants. Studies are investigating stents in the right ventricular outflow tract (RVOT) as an alternative to aortopulmonary shunts. The authors review their institutional experience with RVOT stenting in the high-risk infant with TOF. Data on sequential patients who received RVOT stents were reviewed, with collection of their surgical, echocardiographic, and catheterization data. Size-matched control subjects were identified and outcomes compared. Six infants went to the catheterization lab for RVOT stenting from 2008 to 2010. Five of these patients had placement of an RVOT stent after balloon dilation. The median saturations were 71% on 48% fraction of inspired oxygen (FiO2), with improvement to 94% (p < 0.001) on 39% FiO2 24 h after stent placement. As shown by echocardiography, the diameter of the median right pulmonary artery (RPA) was 2.6 mm (z-score, -3.3), and the diameter of the left pulmonary artery (LPA) was 2.0 mm (z-score, -4.5). Repeat echocardiography before surgery showed a statistically significant increase in RPA and LPA size as well as a modified McGoon ratio (p < 0.05). Four of the five patients subsequently underwent TOF repair. No stent fractures occurred. One patient had repair 10 days after stent placement secondary to stent malposition and tricuspid valve injury. The authors' experience with stents in the RVOT of TOF patients has yielded good results, with significant improvement in oxygen saturations. Patients had successful elective surgical repair and stent removal without longer cardiopulmonary bypass times or recognizable complications compared with shunted patients.

The use of small stents to delay surgical intervention in very young children with critical congenital heart disease

“…Reported success rate ranges between 80% -100%. (5,6,(10)(11)(12)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) Our findings compare favourably with this. Overall, low periprocedural complication rates have been reported in stents used in older children (up to 16%).…”

“…(21,32,33) In younger and smaller patients, complications mostly consist of vascular compromise, haemorrhage and dysrhythmias. Later complications include intrastent proliferation, restenosis and occlusion (3-36%).…”

“…However, as the group of patients is quite diverse, it is difficult to compare the overall mortality to a similar surgical series. (3)(4)(5)(6)(10)(11)(12)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) Mortality in surgical COA repairs in infants for example, is known to be much lower (<2%), but higher in small, complex patients (5 -25%). (3,12) It should be mentioned that one patient was sent home for palliative care and one patient had severe post-operative hypoxia and acidosis.…”

“…(14) Experience in stenting very young and small patients with critical obstructive congenital heart disease is limited and consists mostly of case reports and a few review articles. (5,6,(10)(11)(12)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) The majority reported good immediate results, but limited data on follow-up and final outcomes is available.…”

Stenting of the right ventricular outflow tract as primary palliation for Fallot-type lesions

“…A large number of centres are now considering the option of stenting the RVOT in preference to BT shunting, in particular in low weight neonates [19,20] and hybrid procedures have been reported in premature neonates [21].…”