Asymmetric dual directional steerable catheter sheath

• US 9,326,815 B2
• Filed: 08/05/2013
• Issued: 05/03/2016
• Est. Priority Date: 02/20/2009
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Inventors: Watson, James R.
• Primary Examiner(s): Peffley, Michael
• Assistant Examiner(s): GIULIANI, THOMAS ANTHONY
• Application Number:
  US13/959,388
• Publication Number:
  US 20130317498A1
• Time in Patent Office: 1,002 Days
• Field of Search: 606/46, 606/41, 600/139, 600/140, 600/149, 600/434, 600/435
• US Class Current: 1/1
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61M 2025/0161 wherein the distal tips have two or more deflection regions
• CPC Class Codes: A61M 25/0138 having flexible regions as a result of weakened outer material, e.g. slots, slits, cuts, joints or coils
• CPC Class Codes: A61M 25/0141 having flexible regions as a result of using materials with different mechanical properties
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires

Abstract

A steerable catheter sheath for use in directing a catheter into a desired position is provided. The sheath includes an elongated member configured to receive the catheter therein. The distal end of the elongated member is steerable in two directions, each direction having a different bent configuration, e.g., a sharp curve in one direction and an open arching curve in the other direction. A resilient structure having different bending properties in each of its lateral sides is carried in the distal portion of the elongated member and causes the asymmetric bending. In one embodiment, the resilient structure includes a hypotube with a plurality of notches and slits in the sides. In another embodiment, the resilient structure is covered in an outer coating having different durometer portions. The sheath is particularly useful for accessing left and right pulmonary veins when a transeptal entry approach is used into the left atrium.

Claims

1. A steerable catheter sheath, comprising:

an elongated member having a distal end, a proximal end and a lumen extending between the proximal end and the distal end, the elongated member including a coated wire coil, the coating having sections of varying bending properties, wherein the lumen is configured for receiving a catheter therein;

a first steering wire comprising a distal end coupled to a first lateral side of the elongated member, wherein tensioning the first steering wire bends the distal end of the elongated member in a first direction to create a first bending configuration; and

a second steering wire comprising a distal end coupled to a second lateral side of the elongated member, wherein tensioning the second steering wire bends the distal end of the elongated member in a second direction to create a second bending configuration;

wherein a shape of the first bending configuration is different from a shape of the second bending configuration;

wherein the elongated member further comprises a steering ring disposed within the coated wire coil, wherein the distal ends of the first and second steering wires are coupled to first and second lateral sides, respectively, of the steering ring.

2. The catheter sheath of claim 1, further comprising an outer sheath disposed over the coated wire coil, the outer sheath having a uniform bending property.

3. The catheter sheath of claim 1, wherein the first bending configuration has a first radius of curvature, and the second bending configuration has a second radius of curvature different from the first radius of curvature.

4. The catheter sheath of claim 1, further comprising

a handle coupled to the proximal end of the elongated member;

and

a steering mechanism mounted to the handle, wherein the first and second steering wires have proximal ends coupled to the steering mechanism, such that operation of the steering mechanism tensions one of the first and second steering wires.

5. The catheter sheath of claim 1, wherein a fulcrum point of the first lateral side of the elongated member is distal to a fulcrum point of the second lateral side of the elongated member.

6. A catheter assembly, comprising:

the steerable catheter sheath of claim 1; and

the catheter of claim 1, wherein the catheter is a tissue ablation catheter disposed within the lumen of the elongated member.

7. A method of using the catheter assembly of claim 6, comprising:

introducing the elongated member from a right atrium through an atrial septum into a left atrium;

tensioning the first steering wire to bend the elongated member in the first direction into the first bending configuration to point the distal end of the elongated member towards a right pulmonary vein;

advancing the ablation catheter through the lumen of the elongated member such that the ablation catheter distally extends from the elongated member to contact a first target tissue site within or adjacent to the right pulmonary vein;

ablating the first target tissue site with the ablation catheter;

retracting the ablation catheter into the elongated member;

tensioning the second steering wire to bend the elongated member in the second direction into the second bending configuration to point the distal end of the elongated member towards a left pulmonary vein;

advancing the ablation catheter through the lumen of the elongated member such that the ablation catheter distally extends from the elongated member to contact a second target tissue site within or adjacent to the left pulmonary vein;

ablating the second target tissue site with the ablation catheter; and

retracting the ablation catheter into the elongated member.

8. The method of claim 7, wherein tensioning the first steering wire and tensioning the second steering wire comprise operating a steering mechanism on the proximal end of the elongated member.

9. The method of claim 7, wherein tensioning the first steering wire comprises compressing the first lateral side of the elongated member;

and wherein tensioning the second steering wire comprises compressing the second lateral side of the elongated member.

10. The method of claim 9, wherein tensioning the first steering wire further comprises compressing a first lateral side of the coil and expanding a second lateral side of the coil;

and wherein tensioning the second steering wire further comprises compressing the second lateral side of the coil and expanding the first lateral side of the coil.

11. A method for positioning a catheter in a body, comprising:

providing a steerable guide sheath comprising

an elongated member having a distal end, a proximal end and a lumen extending between the proximal end and the distal end, the elongated member including a coated wire coil, the coating having sections of varying bending properties, wherein the lumen is configured for receiving the catheter therein;

a first steering wire comprising a distal end coupled to a first lateral side of the elongated member, wherein tensioning the first steering wire bends the distal end of the elongated member in a first direction to create a first bending configuration; and

a second steering wire comprising a distal end coupled to a second lateral side of the elongated member, wherein tensioning the second steering wire bends the distal end of the elongated member in a second direction to create a second bending configuration,

wherein a shape of the first bending configuration is different from a shape of the second bending configuration;

wherein the elongated member further comprises a steering ring disposed within the coated wire coil, wherein the distal ends of the first and second steering wires are coupled to first and second lateral sides, respectively, of the steering ring;

introducing the steerable guide sheath into an anatomical cavity;

introducing the catheter into the guide sheath;

deflecting a distal end of the guide sheath in the first direction into the first bending configuration to point the distal end of the guide sheath towards a first target site;

operating the catheter to perform a medical procedure at the first target site;

deflecting the distal end of the guide sheath in the second direction into the second bending configuration different from the first bending configuration to point the distal end of the guide sheath toward a second target site different from the first target site; and

operating the catheter to perform another medical procedure at the second target site.

12. The method of claim 11, further comprising:

advancing the catheter within the guide sheath until a distal end of the catheter extends distally from the distal end of the guide sheath adjacent to the first target site when the distal end of the guide sheath is in the first bending configuration;

retracting the catheter within the guide sheath prior to deflecting the distal end of the guide sheath into the second bending configuration; and

advancing the catheter within the guide sheath until the distal end of the catheter extends distally from the distal end of the guide sheath adjacent to the second target site when the distal end of the guide sheath is in the second bending configuration.

13. The method of claim 11, wherein the anatomical cavity is a heart chamber, the first target site is a right pulmonary vein, and the second target site is a left pulmonary vein.