METHODS AND APPARATUS FOR TREATMENT OF MITRAL VALVE INSUFFICIENCY

• US 20100179424A1
• Filed: 01/07/2010
• Published: 07/15/2010
• Est. Priority Date: 01/09/2009
• Status: Active Grant

• Current Assignee: Recor Medical, Inc. (Otsuka Holdings Company Limited)
• Original Assignee: Recor Medical, Inc. (Otsuka Holdings Company Limited)
• Inventors: Iyer, Mano, Seguin, Jacques, Warnking, Reinhard, Zou, Yong, Jung, Eugene J.
• Granted Patent: US 8,974,445 B2
• Time in Patent Office: Days
• US Class Current: 600/437
• CPC Class Codes: A61B 2017/00106 ultrasonic
• CPC Class Codes: A61B 2017/00703 correcting for movement of heart, e.g. ECG-triggered
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

Mitral valve insufficiency is treated by introducing an expansible device such as a balloon bearing a an ultrasonic transducer into the heart so that the transducer is positioned adjacent the mitral annulus but spaced from the mitral annulus, and actuating the transducer to heat the mitral annulus, denature collagen in the annulus and thereby shrink the annulus.

Claims

1. A method of treating a cardiac valve of a mammalian subject comprising the steps of:

(a) positioning an emitter unit incorporating an ultrasonic transducer in proximity with the valve without completely occluding the annulus of the valve so that the ultrasonic transducer is spaced apart from the annulus; and

(b) actuating the ultrasonic transducer to apply ultrasonic energy to the annulus so as to cause shrinkage of the annulus.

2. The method of claim 1, wherein the subject is a human patient, the valve is the mitral valve and shrinkage is caused by remodeling collagen within the annulus.

3. The method of claim 1, wherein the positioning and actuating steps are performed while the heart is beating.

4. The method of claim 1, wherein the step of positioning the emitter unit is performed so that the ultrasonic transducer is disposed closer to the posterior aspect of the annulus than to the anterior aspect of the annulus.

5. The method of claim 1, wherein the step of actuating the transducer is performed so as to apply ultrasonic energy to the annulus over at least about 25% of the circumference of the annulus in a single actuation of the transducer.

6. The method of claim 1, wherein the step of actuating the transducer is performed so as to apply ultrasonic energy preferentially to the posterior aspect of the annulus.

7. The method of claim 1, wherein the step of positioning the emitter unit includes positioning a proximal portion of a structure encompassing the transducer within the annulus and positioning a distal portion of the structure between the leaflets of the valve.

8. The method of claim 7, wherein the distal portion of the structure has smaller cross-sectional area than the proximal portion of the structure.

9. The method of claim 7, wherein the structure is an expansible structure, the method further comprising the step of expanding the structure, before completion of the positioning step, to an operative condition in which at least a portion of the structure is spaced apart from the ultrasonic transducer.

10. The method of claim 9, wherein the expansible structure includes a balloon, the step of expanding the structure including the step of inflating the balloon with an aqueous liquid.

11. The method of claim 9, wherein the expansible structure comprises at least one adjustable strut configured to position the ultrasonic transducer within the annulus of the valve.

12. The method of claim 7, wherein the positioning step includes advancing an elongated catheter having the emitter unit mounted thereon into a chamber of the heart and advancing a section of the catheter having the emitter unit mounted thereon so as to position the expansible structure within the annulus of the valve.

13. Apparatus for treating a cardiac valve of a mammalian subject comprising:

(a) an elongated catheter having proximal and distal regions;

(b) an emitter unit including an ultrasonic transducer and an expansible structure carried on the distal region of the catheter, the ultrasonic transducer configured to emit ultrasonic energy that causes shrinkage of the annulus of the valve, the expansible structure being constructed and arranged to hold the transducer spaced apart from an annulus of the valve when the expansible structure is in an operative condition and the emitter unit is disposed in proximity to the valve, the expansible structure being constructed and arranged so that the expansible unit will not completely occlude the annulus of the valve.

14. The apparatus of claim 13 wherein the catheter is configured to position the emitter unit adjacent to a posterior aspect of the annulus.

15. The apparatus of claim 13, further comprising a delivery sheath having proximal and distal ends and a sheath steering structure carried on the sheath and operative to selectively bend a bend region of the sheath, the catheter and emitter unit being constructed and arranged so that the distal region of the catheter and the emitter unit can be advanced into a chamber of the heart through the sheath.

16. The apparatus of claim 15, wherein the delivery sheath is constructed and arranged to transmit a torque applied at the proximal end of the sheath to the bend region of the sheath.

17. The apparatus of claim 13, wherein the catheter includes a catheter steering mechanism carried on the catheter and operative to selectively bend a bend region of the catheter proximal to the emitter unit.

18. The apparatus of claim 17, wherein the catheter is constructed and arranged to transmit a torque applied at the proximal end of the catheter to the bend region of the catheter.

19. The apparatus of claim 13, wherein the expansible structure includes an expansible element surrounding the ultrasonic transducer, the apparatus further including a transducer support arranged to hold the transducer substantially spaced apart from the expansible element when the expansible structure is in an expanded condition.

20. The apparatus of claim 19, wherein the expansible element includes a first balloon.

21. The apparatus of claim 20, wherein the first balloon has a major diameter less than a major diameter of the annulus of the valve.

22. The apparatus of claim 20 wherein the first balloon has a major diameter of about 30 mm or less and the catheter is constructed and arranged to place the emitter unit in proximity to the mitral valve.

23. The apparatus of claim 20, wherein the first balloon includes a proximal portion surrounding the ultrasonic transducer and a distal portion extending distal to the proximal portion.

24. The apparatus of claim 20, wherein the distal portion of the first balloon has smaller cross-sectional area than the proximal portion of the first balloon when the first balloon is in an inflated condition.

25. The apparatus of claim 24, wherein the distal portion of the expansible structure tapers in the distal direction.

26. Apparatus as claimed in claim 25 wherein there is an abrupt decrease in diameter at a juncture between the proximal and distal portions of the first balloon that facilitates aligning the ultrasonic transducer with the annulus of the valve, the ultrasonic transducer being disposed at an axial location at or proximal to the axial location of the juncture.

27. The apparatus of claim 20, wherein the expansible element further comprises a second balloon contiguous with the first balloon, the second balloon configured to reflect ultrasonic energy emanating from the ultrasonic transducer.

28. The apparatus of claim 27 wherein at least some of the energy reflected from the second balloon is directed into the annulus of the valve.

29. The apparatus of claim 27, wherein the second balloon blocks at least partially blocks transmission of ultrasonic energy from the transducer to leaflets of the valve.

30. The apparatus of claim 19, wherein the expansible element includes at least one adjustable strut configured to position the ultrasonic transducer within the annulus of the valve.