Right Ventricular Outflow Tract Stenting as Palliation of Critical Tetralogy of Fallot: Techniques and Results

Abstract

Background. Despite current trends toward early primary repair, the surgical systemic-to-pulmonary shunt is still considered the first-choice palliation in patients with critical tetralogy of Fallot (TOF) and duct-dependent pulmonary circulation unsuitable for primary repair. However, stenting of the right ventricular outflow tract (RVOT) is nowadays emerging as an effective alternative to surgical palliation in selected patients. Methods and results. RVOT stenting is usually performed from a venous route, either femoral or, in selected cases, the right internal jugular vein. Less frequently, mostly in pulmonary infundibular/valvar atresia, this procedure can be performed using a hybrid surgical/interventional approach by surgical exposure of the RVOT, puncture of the atretic valve, and stent deployment under direct vision. The size and type of the most appropriate stent may be chosen, based on ultrasound measurements of the RVOT, to cover the right ventricular infundibulum completely and, at the same time, sparing the pulmonary valve, unless significant pulmonary valve annulus hypoplasia and/or supra-valvular stenosis is a significant component of the obstruction. In the large series so far published, early mortality of RVOT stenting is less than 2%, comparing favourably with either Blalock-Thomas-Taussig shunt or early primary repair. In addition, morbidity and clinical sequelae of this approach do not significantly differ from surgical palliation, even if RVOT stenting shows lesser durability and a higher rate of trans-catheter re-interventions over a mid-term follow-up. Finally, similar but more balanced pulmonary artery growth than surgical palliation following RVOT stenting is reported over a mid-term follow-up. Conclusions. RVOT stenting is a technically feasible, well-tolerated, and effective palliation in critical TOF. This approach is cost-effective with respect to surgical palliation either in high-risk neonates or whenever a short-term pulmonary blood flow source is anticipated due to the early surgical repair. It effectively increases pulmonary blood flow, improves arterial saturation, and promotes balanced pulmonary artery growth over a mid-term follow-up.

Personalized Approach in Transcatheter Palliation of Congenital Heart Disease with Duct-Dependent Pulmonary Circulation: Right Ventricular Outflow Tract Stenting vs. Arterial Duct Stenting

“…The tools potentially available to achieve this aim are RVOT stenting or AD stabilization. Both of them showed high efficacy in improving arterial oxygen saturation and promoting balanced pulmonary artery growth [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

“…Over time, several small series showed excellent results of AD stenting employed as a palliation procedure for pulmonary duct-dependent cardiac malformations. The initial experiences over the last few decades [ 14 ] have been encouraging in small series and, over time, larger series, in even more complex anatomic/clinical settings [ 14 , 15 , 16 , 17 , 18 ], clearly showing the superiority of this approach with respect to surgical palliation.…”

“…Over time, large multi-center series have clearly and definitively demonstrated the superiority of AD stenting over surgical shunt in terms of complications, length of hospital stay and mortality and costs [ 15 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ].…”

“…However, despite this potential pathologic blood flow streaming and the occurrence of pulmonary stenosis at the site of duct implantation, the growth of the pulmonary arteries following duct stabilization is good and significantly more balanced than after mBT shunt [ 23 , 26 ]. In addition, the size of the stent potentially used to stabilize the AD may be more precisely set and tailored to patient size and the anticipated time of palliation with respect to a surgical shunt, either in the case of normal size of pulmonary arteries or in the case of hypoplastic or discontinuous pulmonary arteries [ 13 , 14 , 15 , 21 , 28 ]. In fact, in low-weight neonates, it is possible to under-size the stent diameter and further re-dilate it at mid-term follow-up during patient growth [ 14 ].…”

Trans-Catheter Palliation in Tetralogy of Fallot Patients: Complications & Challenges

“…2 Transcatheter palliation has been promising in the management of TOF patients for providing the optimal interim care. 9 Certain complications have been described in association with these procedures. 10 Most of the complications are minor ones, and can be managed easily.…”