Multi-lumen cannula

1. A method for implanting a cannula into the heart of a mammal, wherein said method comprises:

(a) puncturing the heart or blood vessel of said mammal,

(b) inserting a cannula into a chamber of the heart, wherein said cannula comprises a housing having a proximal region, a distal region, and an intermediate region located between said proximal and distal regions, wherein said housing defines a first lumen and a second lumen, wherein said first lumen comprises (a) a proximal end located within said proximal region of said housing and adapted to engage a blood pump and (b) a distal end located within said distal region of said housing and adapted to be positioned within a cardiovascular system, wherein said second lumen comprises (a) a proximal end located within said proximal region of said housing and adapted to engage said blood pump and (b) a distal end located within said intermediate region of said housing and adapted to be positioned within said cardiovascular system, wherein one of said first and second lumens has a generally reniform cross-sectional shape in said intermediate region formed at least by a substantially circular outer arc, a substantially circular inner arc, a first semicircular arc between first ends of the outer and inner arcs, and a second semicircular arc between second ends of the outer and inner arcs, and wherein said distal region is positioned within a blood vessel of said mammal and said intermediate region is positioned within a chamber of the heart of said mammal, and wherein the reniform shape has rounded corners having a radius greater than about ten percent of the radius of the largest circle that can be inscribed within the reniform shape.

2. The method of claim 1 , wherein said method comprises connecting a blood pump to said proximal region of said cannula.

3. The method of claim 2 , wherein said blood pump receives blood from said heart through said second lumen and pumps blood to said blood vessel through said first lumen.

4. The method of claim 3 , wherein said distal end of said first lumen is positioned in the aorta and wherein said distal end of said second lumen is positioned in the left ventricle.

5. The method of claim 3 , wherein said distal end of said first lumen is positioned in the pulmonary artery and wherein said distal end of said second lumen is positioned in the right ventricle.

6. The method of claim 1 , wherein each of the semicircular arcs abut the first and second ends of the outer and inner arcs.

7. A cannula for use with a blood pump, wherein said cannula comprises:

a housing having a proximal region, a distal region, and an intermediate region located between said proximal and distal regions, wherein said housing defines a first lumen and a second lumen,

wherein said first lumen comprises:

(a) a proximal end located within said proximal region of said housing and adapted to engage said blood pump, and

(b) a distal end located within said distal region of said housing and adapted to be positioned within a cardiovascular system,

wherein said second lumen comprises:

(a) a proximal end located within said proximal region of said housing and adapted to engage said blood pump, and

(b) a distal end located within said intermediate region of said housing and adapted to be positioned within said cardiovascular system,

wherein one of said first and second lumens has a generally reniform cross-sectional shape in said intermediate region formed at least by a substantially circular outer arc, a substantially circular inner arc, a first semicircular arc between first ends of the outer and inner arcs, and a second semicircular arc between second ends of the outer and inner arcs, and wherein the reniform shape has rounded corners having a radius greater than about ten percent of the radius of the largest circle that can be inscribed within the reniform shape.

8. The cannula of claim 7 , wherein said intermediate region of said housing comprises a single outer wall that houses said first and second lumen.

9. The cannula of claim 8 , wherein said single outer wall is flexible.

10. The cannula of claim 7 , wherein one of said first or second lumen has a generally circular cross-sectional shape.

11. The cannula of claim 10 , wherein said intermediate region comprises a septum configured to form a convex surface of said generally reniform cross-sectional shape and a concave surface of said generally circular cross-sectional shape.

12. The cannula of claim 11 , wherein said septum is flexible.

13. The cannula of claim 7 , wherein said intermediate region comprises a sensor, sensor leads, or a fluid port.

14. The cannula of claim 13 , wherein said sensor is a pressure transducer, a thermister, an ultrasonic probe, or a combination thereof.

15. The cannula of claim 7 , wherein said intermediate region comprises a third or a fourth lumen.

16. The cannula of claim 15 , wherein said third or fourth lumen comprises a fluid port.

17. The cannula of claim 7 , wherein said housing comprises a single outer wall in said intermediate region that houses said first and second lumen, a first outer wall in said proximal region that houses said first lumen, and a second outer wall in said proximal region that houses said second lumen.

18. The cannula of claim 7 , wherein said distal ends of said first and second lumen bifurcate from said intermediate region of said housing.

19. The cannula of claim 7 , wherein said intermediate region comprises at least one malleable wire.

20. The cannula of claim 7 , wherein each of the semicircular arcs abut the first and second ends of the outer and inner arcs.

21. A system for providing blood flow to a mammal comprising:

(i) a cannula, wherein said cannula comprises a housing having a proximal region, a distal region, and an intermediate region located between said proximal and distal regions, wherein said housing defines a first lumen and a second lumen, wherein said first lumen comprises (a) a proximal end located within said proximal region of said housing and adapted to engage a blood pump and (b) a distal end located within said distal region of said housing and adapted to be positioned within a cardiovascular system, wherein said second lumen comprises (a) a proximal end located within said proximal region of said housing and adapted to engage said blood pump and (b) a distal end located within said intermediate region of said housing and adapted to be positioned within said cardiovascular system, wherein one of said first and second lumens has a generally reniform cross-sectional shape in said intermediate region formed at least by a substantially circular outer arc, a substantially circular inner arc, a first semicircular arc between first ends of the outer and inner arcs, and a second semicircular arc between second ends of the outer and inner arcs, and wherein the reniform shape has rounded corners having a radius greater than about ten percent of the radius of the largest circle that can be inscribed within the reniform shape; and

(ii) a blood pump.

22. The system of claim 21 , wherein said proximal end of said first lumen is connected to the outflow of said blood pump and wherein said proximal end of said second lumen is connected to the inflow of said blood pump.

23. The system of claim 21 , wherein each of the semicircular arcs abut the first and second ends of the outer and inner arcs.