Expandable mechanical hemodynamic support systems, devices, and methods
Some embodiments of percutaneous ventricular assist devices have a two-part design that includes a housing component and a separately deployable rotatable inner catheter component. The housing component can include an expandable pump housing. The inner catheter can include an expandable pump impeller and an associated flexible drive shaft. The drive shaft can be coupled to a motor located external to the patient. The motor can rotate the drive shaft to spin the pump impeller inside of the pump housing, causing blood to be pumped within the patient. In some embodiments, the pump impeller is inflatable or self-expandable. The two-part percutaneous ventricular assist devices with inflatable or self-expandable pump impellers are designed to have very small delivery profiles. Accordingly, various deployment modalities, including radial artery deployment, are practicable using the two-part percutaneous ventricular assist devices described herein.
1. A percutaneous ventricular assist device comprising:
a housing component comprising:
an elongate drive shaft housing defining a lumen;
a pump housing attached to a distal end portion of the drive shaft housing, the pump housing being radially reconfigurable between: (i) a low-profile configuration configured for trans-vascular advancement to a target location within a patient and (ii) a radially expanded configuration; and
an inlet cannula extending from the pump housing, wherein the pump housing has a larger outer diameter than the inlet cannula when the pump housing is in the radially expanded configuration; and
a rotatable inner catheter comprising a pump impeller attached to a distal end portion of an elongate drive shaft, wherein the rotatable inner catheter is deployable separately from the housing component by inserting the rotatable inner catheter into the lumen of a deployed housing component and advancing the rotatable inner catheter along the lumen until the pump impeller is within the pump housing,
wherein, during deployment of the rotatable inner catheter, the pump impeller is slidable along an entirety of the lumen when the pump impeller is in a radially collapsed configuration as the rotatable inner catheter is advanced along the lumen, and
wherein the pump impeller is radially expandable to an operable configuration when the pump impeller is within the radially expanded configuration of the pump housing in the target location within the patient.
2. The percutaneous ventricular assist device of claim 1 , wherein the pump impeller is movable relative to the pump housing in response to retraction or advancement of the drive shaft relative to the drive shaft housing.
3. The percutaneous ventricular assist device of claim 1 , wherein the drive shaft defines an inflation lumen, and wherein the pump impeller is radially expandable in response to receiving an inflation fluid supplied to the pump impeller via the inflation lumen.
4. The percutaneous ventricular assist device of claim 3 , wherein the inner catheter further comprises:
a drive shaft hub attached to a proximal end portion of the drive shaft; and
a drive shaft hub seal coupled with the hub and sealing a proximal end of the inflation lumen.
5. The percutaneous ventricular assist device of claim 3 , further comprising a motor, wherein the inner catheter further comprises a drive shaft hub attached to a proximal end portion of the drive shaft, wherein the drive shaft hub is configured to be coupled to the motor, and wherein the motor and the drive shaft hub are configured to allow an inflation fluid to pass into the inflation lumen via the drive shaft hub while the drive shaft hub is coupled to the motor.
6. The percutaneous ventricular assist device of claim 1 , wherein the percutaneous ventricular assist device is configured to pump blood by rotation of the pump impeller while the pump impeller is positioned in the pump housing and without any mechanical bearing or bushing between the pump impeller and the pump housing.
7. The percutaneous ventricular assist device of claim 1 , wherein the pump housing is configured to self-expand to the radially expanded configuration.
8. The percutaneous ventricular assist device of claim 1 , wherein the percutaneous ventricular assist device is configured to pump blood when: (i) the pump impeller is positioned in the pump housing at a target location within a patient, (ii) the pump impeller and the pump housing are expanded, and (iii) the drive shaft is rotated by a motor located external to the patient.
9. The percutaneous ventricular assist device of claim 1 , wherein the inlet cannula defines one or more inlet openings, and wherein the pump housing defines one or more outlet openings.
10. The percutaneous ventricular assist device of claim 1 , wherein the pump impeller is inflatable from the low-profile configuration to the radially expanded configuration in which the pump impeller is configured to pump blood when rotating relative to the pump housing.
11. The percutaneous ventricular assist device of claim 1 , wherein the drive shaft housing allows a purge fluid or blood to flow between the pump housing and the pump impeller to provide a hydrodynamic bearing between the pump housing and the pump impeller.