Cardiac bypass catheter system and method of use

Abstract

A medical device assembly is adapted to isolate the heart from systemic circulation while perfusing oxygenated blood to the systemic arterial circulation during a minimally invasive bypass procedure. The assembly includes an arterial catheter with an external shunt valve which forms an anchor to secure the distal end portion within the aortic arch and which also forms a funnel which shunts antegrade aortic blood flow from the aortic root, into a distal flow port and through an internal flow lumen in the catheter, out an intermediate flow port along the catheter proximally of the anchor, and into the systemic arterial circulation. A distal internal valve is further provided within the internal flow lumen between the distal and intermediate flow ports. The distal internal valve selectively occludes the shunted antegrade aortic blood flow between the distal flow port and the intermediate flow port and isolates the left heart chambers from the systemic arterial circulation. Oxygenated blood may then flow from a cardiopulmonary bypass pump, distally through the internal flow lumen, out the intermediate port. The assembly also includes a venous catheter which aspirates venous blood from the vena cavae and into the cardiopulmonary bypass pump while substantially isolating the right heart chambers from the vena cavae and without circumferentially engaging the internal walls of the vena cavae. Distal and intermediate external valves are positioned along the venous catheter within the superior and inferior vena cava, respectively, and between the sinus venarum into the right atrium and either a distal or intermediate flow port, also respectively. The flow ports communicate with a cardiopulmonary bypass pump through at least one flow lumen through the catheter. Each external valve is adjustable to have an outer diameter which is slightly less than the inner diameter of the respective vena cava so that venous blood is substantially occluded from flowing into the sinus venarum and is instead aspirated into the adjacent flow port. A leakage port may also be provided between the distal and intermediate flow ports. The venous catheter may alternatively include an external valve with a valve member which is adjustable from a first radial position at a discrete location around the catheter's circumference to a radially displaced position within the right atrium.