Corkscrew shape for right-sided cardiac device
A catheter includes a catheter body, a pump assembly and a cannula. The pump assembly can be disposed at a distal end of the catheter body and has a distal portion. The cannula can be coupled to the distal end portion of the pump assembly and can include a proximal cannula portion and a distal cannula portion. The distal cannula portion has an approximately helical shape which can allow the cannula to be inserted into a patient's right heart and pump blood therethrough. In certain implementations, the distal tip of the helical shape has a slight bias relative to the main helix to further facilitate delivery of the device. In certain applications this bias is toward the central axis of the helix.
1. A catheter configured for delivering an intravascular blood pump within a patient's vasculature, comprising:
a catheter body having a distal end, a proximal end, and a first longitudinal axis;
a pump assembly disposed at the distal end of the catheter body, the pump assembly having a distal end portion;
a cannula coupled to the distal end portion of the pump assembly, the cannula comprising a proximal cannula portion having inlet ports, and a distal cannula portion having outlet ports, the distal cannula portion having a pre-formed shape that is approximately helical, with a curvature that mimics the curvature of an anatomical pathway that traverses the inferior vena cava, right atrium, tricuspid valve, right ventricle and pulmonary valve of the patient's heart such that when the distal cannula portion is positioned along the anatomical pathway, the inlet ports are positioned in the inferior vena cava and the outlet ports are positioned in the pulmonary artery;
wherein the helical shape approximated by the distal cannula portion has a second axis parallel to and offset from the first longitudinal axis of the catheter body.
2. The catheter of claim 1 , wherein a distal tip of the cannula is angled toward a center of the second axis.
3. The catheter of claim 2 , wherein the helical shape approximated by the distal cannula portion has a radius between about 10 mm and 50 mm.
4. The catheter of claim 3 , wherein the helical shape approximated by the distal cannula portion has a radius between about 20 mm and 40 mm.
5. The catheter of claim 4 , wherein the helical shape approximated by the distal cannula portion has a radius of about 30 mm.
6. The catheter of claim 1 , wherein the helical shape approximated by the distal cannula portion has a pitch between about 50 mm and 140 mm.
7. The catheter of claim 6 , wherein the helical shape approximated by the distal cannula portion has a pitch between about 70 mm and 120 mm.
8. The catheter of claim 7 , wherein the helical shape approximated by the distal cannula portion has a pitch of about 90 mm.
9. The catheter of claim 1 , wherein the helical shape approximated by the distal cannula portion completes one turn.
10. The catheter of claim 1 , wherein a length of the distal cannula portion is about two-thirds of a total length of the cannula.
11. The catheter of claim 1 , wherein the cannula has a total length of about 17 cm.
12. The catheter of claim 1 , wherein the cannula in configured to extend through the tricuspid valve and the pulmonary valve into the inferior vena cava when positioned in the right heart.
13. The catheter of claim 1 , wherein the cannula is configured to be approximately perpendicular to a plane defined by the tricuspid valve during entry through the right atrium into the right ventricle.
14. The catheter of claim 1 , wherein the curvature of the distal end of the cannula is configured such that a distal tip of the cannula points toward the pulmonary valve after passing through the tricuspid valve.
15. The catheter of claim 1 , wherein the helical shape of the cannula is configured to match an average patient anatomy of the right atrium, tricuspid valve, right ventricle, pulmonary valve and pulmonary artery during placement in the right heart.
16. The catheter of claim 1 , wherein the cannula is sized for percutaneous delivery.
17. The catheter of claim 13 , wherein the cannula has a diameter of about 10 Fr.
18. The catheter of claim 1 , further comprising a flexible extension coupled to the distal cannula portion.
19. The catheter of claim 1 , wherein the catheter is configured for percutaneous insertion into a patient through the anatomical pathway.