Guidable intravascular blood pump and related methods

1. A method for perfusing a patient with an intravascular blood pump system, the intravascular blood pump system comprising (i) an intravascular blood pump comprising a rotor having a rotor hub tapering in the distal direction, at least one blade extending radially outward from the rotor hub, the hub having a distal end extending distally beyond the most distal portion of the blade and a shroud within which the rotor is rotatably disposed; (ii) a cannula extending from the shroud and comprising an outer cannula surface, the outer cannula surface having a substantially circular cross-section along a portion of its length; (iii) a first lumen in fluid communication with the intravascular blood pump and operatively arranged to deliver purge fluid to the intravascular blood pump; and (iv) a guide mechanism configured as a second lumen having a proximal end and a distal end, the guide mechanism adapted to guide a distal portion of said intravascular blood pump system to a predetermined location within the circulatory system of a patient, wherein an axis coaxial with and extending through a portion of said guide mechanism extends through a region delimited by the outer cannula surface, and wherein the guide mechanism is configured to allow for a guide wire to slideably advance therealong, the method comprising the steps of:

progressing a guide wire to a predetermined location in the circulatory system of the patient; and

advancing the blood pump system along the guide wire to the predetermined location.

2. The method of claim 1 , wherein the rotor comprises a second blade extending radially from the rotor hub and the rotor hub is generally conical.

3. The method of claim 1 , wherein a distal end of the cannula is open in order to enable the guide wire to pass axially through the distal end of the cannula.

4. The method of claim 1 , wherein the guide mechanism is configured such that the guide wire passes through the region delimited by the outer cannula surface at a location proximal to where the guide wire establishes slidable contact with the guide mechanism.

5. The method of claim 1 , wherein the second lumen has an inner diameter along a portion of its length that is substantially smaller than an outer diameter of the outer cannula surface, and the lengh of the second lumen is substantially longer than the inner diameter of the second lumen.

6. The method of claim 1 , further comprising a guide catheter, wherein the guide catheter is configured to facilitate the placement of the guide wire into the heart.

7. The method of claim 1 , further comprising:

an elongate catheter extending proximally with respect to the intravascular blood pump; and a blood pressure detection mechanism comprising a fluid column disposed within the catheter and configured to detect the pressure of the blood proximate the intravascular blood pump.

8. The method of claim 1 , wherein the cannula is operatively arranged to bend at a location between distal and proximal ends thereof.

9. The method of claim 1 , further comprising a first conduit and a second conduit, at least one of the first conduit or the second conduit terminating in a fitting that is configured to be located outside a patient when the intravascular blood pump and cannula are located inside the patient, at least one of the first conduit and second conduit in fluid communication with the first lumen.

10. A method for perfusion a patent with an intravascular blood pump system, the intravascular blood pump system comprising (i) an intravascular blood pump comprising a rotor having a rotor hub tapering in the distal direction and at least one blade extending radially outward from the rotor hub, the intravascular blood pump coupled to a catheter on a proximal end and a cannula on a distal end; (ii) a first set and a second set of apertures establishing fluid communication between an interior of the cannula and an exterior region of the cannula, wherein the first set of apertures is located in proximity to the rotor and the second set of apertures is spaced apart from and located distal to the first set of apertures towards a distal region of the cannula; (iii) a guide mechanism configured as an elongate lumen and adapted to guide said intravascular blood pump, cannula, and catheter to a predetermined location within the circulatory system of a patient; and (iv) a blood pressure detection mechanism comprising a fluid column configured to detect the pressure of the blood proximate the intravascular blood pump; wherein the elongate lumen (a) is sized substantially smaller than an inner diameter of the cannula and intravascular blood pump; (b) is arranged coaxially with at least one of a distal end or a proximal end of the cannula, and (c) is arranged in series longitudinally with the cannula: the method comprising:

advancing a guide wire to a predetermined location in the circulatory system of the patient; and

advancing the blood pump system along the guide wire to the predetermined location.

11. The method of claim 10 , further comprising a guide wire and a guide catheter, wherein the guide catheter is configured to facilitate the placement of the guide wire through the vasculature into the heart.

12. The method of claim 10 , wherein the cannula comprises an outer cannula surface having a substantially circular cross-section along a portion of its length, and the cannula is reinforced with a spiral wire.

13. The method of claim 10 , further comprising a plurality of egress flow ports disposed in a shroud of the intravascular blood pump, and a plurality of ingress flow ports disposed at a location spaced apart from and distal to the egress flow ports.

14. The method of claim 13 , wherein the ingress flow ports comprise an end port located at the cannula distal end and a plurality of ports located about the cannula and proximal to the end port.

15. The method of claim 10 , wherein the first set of apertures are egress ports and the second set of apertures are ingress ports, and wherein the egress ports are configured to direct blood passing through the interior of the cannula and towards the rotor in a direction that is both proximal and radially outward with respect to the rotor hub.

16. The method of claim 10 , wherein the elongate lumen extends centrally through the cannula and blood pump.

17. The method of claim 10 , wherein the elongate lumen is proximal to the cannula.

18. The method of claim 10 , wherein the cannula is operatively arranged to bend at a location between distal and proximal ends thereof.

19. The method of claim 10 , wherein the distal end of the cannula is open to enable the guide wire to pass axially through the distal end of the cannula.

20. A method for perfusion a patent with an intravascular blood pump system, the intravascular blood pump system is configured to be advanced to a predetermined location in a patient's circulatory system and comprises (i) an intravascular blood pump, the intravascular blood pump comprising a rotor having a generally conical rotor hub tapering in the distal direction, at least two blades extending radially from the rotor hub, the generally conical rotor hub having a distal tip extending distally beyond the blades; (ii) a cannula extending distally from the intravascular blood pump; (iii) a plurality of ingress ports located towards the distal region of the cannula and a plurality of egress ports located in proximity to the blood pump such that movement of fluid proximally through an interior region of the cannula is steered towards the egress ports; (iv) a guide wire having a cross-section substantially smaller than the cannula; and (v) an elongate lumen, the elongate lumen (a) having a luminal interior sized smaller than an inside diameter of the cannula and sufficiently large enough to accommodate the guide wire when the guide wire is advanced therealong, (b) arranged coaxially with respect to at least one of a distal end or a proximal end of the cannula, and (c) arranged in series longitudinally with the cannula, the method comprising:

advancing the guide wire to a predetermined location in the circulatory system of the patient; and

advancing the blood pump along the guide wire to the predetermined location.

21. The method of claim 20 , wherein the lumen is proximal with respect to the cannula.

22. The method of claim 20 , wherein the distal end of the cannula is open to enable the guide wire to pass axially through the distal end of the cannula.