Pulmonary Artery Resistor

Pulmonary Artery Resistor

Improving blood flow in children with congenital heart disease

The National Institute of Health needed a way to redistribute blood in children with CHD. Vivonics designed a stent that deploys into the pulmonary artery that allows for minimally invasive adjustment to blood distribution

Congenital heart disease (CHD) refers to the various malformations of the heart and surrounding vessels that occur prior to birth.  Almost 1% of children are born with some form of significant CHD, and CHD remains a leading cause of infant death in the United States.  Many infants with CHD develop exuberant blood flow to their lungs that, if left untreated, will result in overwhelming congestive heart failure and death.  For example, in ventricular septal defect (VSD), the most common type of CHD occurring in 37% of cases, holes in the septum allows oxygen rich blood entering into the left ventricle from the lungs to leak out to the right ventricle and escape out the pulmonary artery instead of out the aorta and to the rest of the body.  When, however, complete surgical repair in infancy is not possible or not ideal, it becomes imperative that the pulmonary blood flow be restricted, in order to allow the infant to thrive to an age where repair is feasible.  The current approach for many of these children is to surgically limit their pulmonary blood flow.  This can be accomplished by cinching down on the main or branch pulmonary arteries with a band (pulmonary artery band) or by completely removing the natural flow to the lungs and replacing it with a controlled source of blood flow through a Gortex shunt or surgical conduit.  Although effective in controlling pulmonary blood flow, the pulmonary artery band results in distortion of the pulmonary arteries which can negatively impact future surgical intervention.  In addition it can only be adjusted through additional surgery.  Similarly, placement of a surgical shunt or conduit can result in distortion of the pulmonary arteries.  In addition, these artificial connections have the potential for thrombosis, distortion and occlusion, which can have fatal consequences.  

The development of a percutaneous intravascular pulmonary artery resistor would avoid the complications associated with these current techniques and have the potential for non-surgical adjustment over time to accommodate for growth.  The Vivonics solution is a minimally invasive surgery (MIS) device that implants within the main pulmonary artery in order to elevate flow resistance to palliate the patient's CHD symptoms and move toward systemic flow. 

*Product under development, not yet FDA approved