Magnetic Resonance Imaging–Guided Transcatheter Cavopulmonary Shunt

Abstract

OBJECTIVES The aim of this study was to test the hypothesis that real-time magnetic resonance imaging (MRI) would enable closed-chest percutaneous cavopulmonary anastomosis and shunt by facilitating needle guidance along a curvilinear trajectory, around critical structures, and between a superior vena cava “donor” vessel and a pulmonary artery “target.” BACKGROUND Children with single-ventricle physiology require multiple open heart operations for palliation, including sternotomies and cardiopulmonary bypass. The reduced morbidity of a catheter-based approach would be attractive. METHODS Fifteen naive swine underwent transcatheter cavopulmonary anastomosis and shunt creation under 1.5-T MRI guidance. An MRI antenna-needle was advanced from the superior vena cava into the target pulmonary artery bifurcation using real-time MRI guidance. In 10 animals, balloon-expanded off-the-shelf endografts secured a proximal end-to-end caval anastomosis and a distal end-to-side pulmonary anastomosis that preserved blood flow to both branch pulmonary arteries. In 5 animals, this was achieved with a novel, purpose-built, self-expanding device. RESULTS Real-time MRI needle access of target vessels (pulmonary artery), endograft delivery, and superior vena cava shunt to pulmonary arteries were successful in all animals. All survived the procedure without complications. Intraprocedural real-time MRI, post-procedural MRI, x-ray angiography, computed tomography, and necropsy showed patent shunts with bidirectional pulmonary artery blood flow. CONCLUSIONS MRI guidance enabled a complex, closed-chest, beating-heart, pediatric, transcatheter structural heart procedure. In this study, MRI guided trajectory planning and reproducible, reliable bidirectional cavopulmonary shunt creation.

First-in-Human Closed-Chest Transcatheter Superior Cavopulmonary Anastomosis

“…Our group and others have explored numerous related preclinical approaches to endovascular bypass over the past decade (12,13,23). The vessel-to-vessel crossing technique was first described by our group (14).…”

“…In animals, our group and others have used needle (12) and radiofrequency perforation (23) for unidirectional “classic” Glenn shunts (SVC solely to the right PA) and more recently the contemporary, and more technically demanding, bidirectional (both PAs) version (13). In post-operative Fontan patient case reports, small pulmonary artery-to-atria fenestrations (24) and medium-sized PA reconnections (25) have been created.…”

“…Ultimately, we were successful in using trans-septal needle puncture aimed at balloon targets, followed by covered stent placement in animals to create a “classic Glenn” or unidirectional cavopulmonary anastomosis (SVC connected exclusively to the right PA and excluding the left PA) (12). More recently, we accomplished transcatheter bidirectional cavopulmonary anastomosis (SVC blood flow distributed to both the right and left PA) using real-time cardiac magnetic resonance imaging guidance in animals (13). …”

“…For more than 2 decades, our group and others have been working to develop minimally invasive, nonsurgical therapy for patients with single-ventricle physiology (11–13). We describe a novel entirely transcatheter nonsurgical closed-chest procedure, which is the anatomic equivalent of the contemporary surgical superior cavopulmonary anastomosis.…”

Real‐time MRI guidance of cardiac interventions

“…27 Shunts may also be required to direct flow of blood from one structure to another such as a Blalock-Taussig shunt and usually require cardiac surgery. Real-time MRI guidance with superior soft tissue visualization compared to x-ray has facilitated multiple novel procedures in preclinical studies including a percutaneous cavopulmonary shunt; 28 ultimately, the ability to perform such novel procedures in patients, avoiding the need for surgery, will drive clinical adoption of interventional cardiac MR techniques.…”