Indwelling Nerve Block Catheters

• US 20110218529A1
• Filed: 03/05/2011
• Published: 09/08/2011
• Est. Priority Date: 03/05/2010
• Status: Active Grant

• Current Assignee: SRI International, Inc., Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Original Assignee: SRI International, Inc., Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Inventors: Ramamurthi, Radhamangalam J., Garcia, Pablo E., Shakespear, Karen Frances, Qin, Chunyuan, Young, Sarah J., Dutta, Sanjeev, Krane, Elliot
• Granted Patent: US 8,825,129 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 5/388 Nerve conduction study, e.g. detecting action potential of peripheral nerves
• CPC Class Codes: A61M 2025/0166 Sensors, electrodes or the like for guiding the catheter to a target zone, e.g. image guided or magnetically guided
• CPC Class Codes: A61M 2202/048 Anaesthetics
• CPC Class Codes: A61M 25/0026 Multi-lumen catheters with stationary elements catheter assemblies comprising a catheter in combination with a guide tube, sheath or sleeve A61M2025/0681; catheters comprising telescoping coaxial elements A61M2025/0175
• CPC Class Codes: A61M 25/0102 Insertion or introduction using an inner stiffening member, e.g. stylet or push-rod
• CPC Class Codes: A61M 25/0105 Steering means as part of the catheter or advancing means; Markers for positioning systems for detection of markers A61B
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence

Abstract

A nerve block catheter system employs an indwelling, flexible catheter comprising a tissue lock to retain the catheter tip in pharmacologically proximity to a target nerve and optionally, a decoupler that insulates the tip of the catheter from proximal tissue movement.

Claims

1. A nerve block catheter system comprising a flexible indwelling catheter and a rigid stylet, the catheter and stylet each comprising a proximal portion and a distal portion terminating in a distal tip, wherein:

(a) the distal portion of the catheter comprises a tissue lock which engages target site tissue without axially advancing or retracting the tip whereby the tip is retained in pharmacologically proximity to a target nerve, and the proximal portion of the catheter comprises an actuator of the tissue lock,

(b) the stylet is insertable axially in the catheter, providing rigidity to the catheter system during placement,

(c) the distal tip of the catheter and/or the stylet is sufficiently sharp to push through to the target site tissue, and

(d) the distal portion of the catheter and/or stylet comprises an electrode that senses and/or stimulates nerve electrical activity for placement.

2. The nerve block catheter system of claim 1 wherein the tissue lock is reversible and reversibly engages target site tissue without axially advancing or retracting the tip.

3. The nerve block catheter system of claim 1 wherein the system further comprises a skin-mounted decoupler that insulates the tip of the catheter from proximal tissue movement.

4. The nerve block catheter system of claim 1 wherein the decoupler comprises a hub comprising a cylindrical chamber that absorbs axial movement of the catheter

5. The nerve block catheter system of claim 1 wherein the catheter comprises a compliant polymeric material.

6. The nerve block catheter system of claim 1 wherein the lock comprises one or more protrusions and the actuator alternatively causes the protrusions to engage or disengage the target site tissue.

7. The nerve block catheter system of claim 1 wherein the protrusions are bulges, bladders, barbs, or threads.

8. The nerve block catheter system of claim 1 wherein the catheter comprises first and second axial lumens, the first lumen comprising a distal aperture that conducts anesthetic in pharmaceutical proximity to the target nerve, and the second lumen comprising an aperture that conducts a flowable adhesive or vacuum that provide the lock.

9. The nerve block catheter system of claim 1 wherein the first and second lumens are inner and outer coaxial lumens, and the aperture of the second lumen is one of a plurality of radially-oriented apertures.

10. The nerve block catheter system of claim 1 wherein the lock comprises one or more apertures and the actuator comprises a valve wherein opening and closing the valve creates and releases a tissue-adhering vacuum at the apertures.

11. The nerve block catheter system of claim 1 wherein the lock comprises one or more apertures and the actuator comprises a valve wherein opening and closing the valve creates and releases a tissue-adhering vacuum at the apertures.

12. The nerve block catheter system of claim 1 wherein the lock further comprises a chamfer or ridge at the distal tip of the catheter that prevents axial motion of the catheter by causing target site tissue to embed in the tip.

13. The nerve block catheter system of claim 1 wherein the actuator comprises a rotatable knob wherein rotation of the knob alternatively causes the lock to engage or disengage the target tissue.

14. The nerve block catheter system of claim 1 wherein the actuator is a lever or button, wherein pushing or pulling on the lever or button alternatively causes the lock to engage or disengage the target tissue.

15. The nerve block catheter system of claim 1 wherein the sensor is one of a plurality of electrodes, and the distal portion of the catheter and the distal portion of the stylet comprise the sensors.

16. The nerve block catheter system of claim 1 wherein the electrode senses nerve native and/or evoked electrical activity.

17. The nerve block catheter system of claim 1 wherein the electrode stimulates nerve activity which is detected as patient movement or sensation.

18. The nerve block catheter system of claim 1 wherein the electrode is one of a plurality of independent electrodes that resolve electric fields of the nerve for placement.

19. The nerve block catheter system of claim 1 wherein the proximal portion comprises a hydrogel to decouple the tip from movement of surrounding muscle and/or skin.

20. A method of using the nerve block catheter system of claim 1, comprising one or more steps:

tracking the nerve with the electrode;

placing the catheter;

engaging the lock;

delivering a medicament;

detecting a resultant therapeutic effect;

disengaging the lock; and

/or

removing the catheter.