APPARATUS FOR STEREOTACTIC NEUROSURGERY

• US 20110009879A1
• Filed: 10/06/2008
• Published: 01/13/2011
• Est. Priority Date: 10/08/2007
• Status: Abandoned Application

• Current Assignee: Renishaw PLC
• Original Assignee: Renishaw PLC
• Inventors: Gill, Steven Streatfield, Derrick, Hugo George, Fielder, Paul David
• Application Number:
  US12/733,562
• Publication Number:
  US 20110009879A1
• Time in Patent Office: Days
• US Class Current: 606/130
• CPC Class Codes: A61B 17/3403 Needle locating or guiding means guides for suture needles A61B17/0482; guiding or tracking by nuclear magnetic resonance G01R33/285
• CPC Class Codes: A61B 17/3415 for introducing tubes or catheters, e.g. gastrostomy tubes, drain catheters A61B17/3417 takes precedence; body piercing catheter guide needles A61M25/06
• CPC Class Codes: A61B 17/3423 Access ports, e.g. toroid shape introducers for instruments or hands access sites for liquids A61M39/0247
• CPC Class Codes: A61B 2017/3407 including a base for support on the body
• CPC Class Codes: A61B 2090/103 Cranial plugs for access to brain
• CPC Class Codes: A61B 90/11 with guides for needles or instruments, e.g. arcuate slides or ball joints

Abstract

A skull mount (50;150;170;200;300) is described that is attachable to a hole (60) formed in the skull. The skull mount (50;150;170;200;300) comprises an alignment guide (62;152;172;216;306) defining an alignment axis (22;210;312) along which neurosurgical instruments can be passed. The skull mount, when attached to a hole in a skull, is arranged such that it does not substantially protrude from the outermost surface of the skull and does not extend into the brain parenchyma. Also described is a neurosurgical alignment instrument (30,206) for aligning such a skull mount (50;150;170;200;300) that comprises an elongate shaft (32) and an element (34,36) protruding from the distal end of the elongate shaft (32) for engaging and aligning the alignment guide (62;152;172;216;306) of an associated skull mount (50;150;170;200;300). When the alignment instrument is engaged with a skull mount attached to a hole formed in the skull, the protruding element passes through the alignment guide of the skull mount and into the cortex of the subject'"'"'s brain.

Claims

1. A skull mount attachable to a hole formed in the skull of a subject, the skull mount comprising an alignment guide defining an alignment axis along which neurosurgical instruments can be passed, characterised in that the skull mount, when attached to a hole in a skull, does not substantially protrude from the outermost surface of the skull and does not extend into the brain parenchyma.

2. A skull mount according to claim 1 that, when attached to a hole formed in the skull of a subject, is substantially flush to the outermost surface of the skull.

3. A skull mount according to any preceding claim suitable for long term, subcutaneous, implantation within a subject.

4. A skull mount according to any preceding claim comprising a member defining the alignment guide and a socket attachable to a hole formed in a subject'"'"'s skull, wherein the member defining the alignment guide is retained by, and is moveable relative to, the socket.

5. A skull mount according to any one of claims 1 to 3 wherein the alignment guide comprises a member having a channel formed therethrough defining the alignment axis, wherein the orientation of the skull mount within a hole formed in the skull is set during attachment of the skull mount to the skull to align the alignment axis with the required axis of neurosurgical instrument insertion.

6. A skull mount according to any preceding claim wherein the alignment guide can be immobilised relative to the skull after implantation.

7. A skull mount according to any preceding claim that can be affixed to a hole formed in the skull of a subject with adhesive.

8. A skull mount according to any preceding claim comprising a recess that allows releasable attachment of the skull mount to a neurosurgical alignment instrument, wherein the surface defining the recess carries a screw thread for releasable attachment to a complimentary protrusion provided on an associated neurosurgical alignment instrument.

14. Neurosurgical apparatus comprising;

a stereoguide for guiding neurosurgical instruments along a defined axis of insertion;

a skull mount according to any one of claims 1 to 8; and

a skull mount alignment instrument according to any one of claims 9 to 13 for aligning the alignment axis of the skull mount;

wherein, in use, the skull mount alignment instrument is carried by the stereoguide and aligns the alignment axis of the skull mount with the axis of insertion defined by the stereoguide.

15. An apparatus according to claim 14 comprising an applicator instrument for retaining a guide wire, wherein, in use, the applicator instrument is carried by the stereoguide and allows a guide wire to be passed through the alignment guide of an implanted skull mount and into the brain parenchyma, the stereoguide and the alignment guide of the skull mount acting to guide the guide wire along the defined axis of insertion.

16. An apparatus according to any one of claims 14 to 15 further comprising at least one of a guide wire, a catheter, a guide tube, an electrode and a biopsy needle.

9. A neurosurgical alignment instrument for aligning a skull mount, the skull mount being attachable to a hole formed in the skull of a subject and including an alignment guide defining an alignment axis along which neurosurgical instruments can be passed, the instrument comprising;

an elongate shaft; and

an element protruding from the distal end of the elongate shaft for engaging and aligning the alignment guide of an associated skull mount;

characterised in that, when the instrument is engaged with a skull mount attached to a hole formed in the skull of a subject, the protruding element passes through the alignment guide of the skull mount and into the cortex of the subject'"'"'s brain.

10. An instrument according to claim 9 wherein the protruding element comprises a wire that is substantially co-axial with longitudinal axis of the elongate shaft.

11. An instrument according to any one of claims 9 to 10 wherein, in use, the protruding element is arranged to penetrate 10 mm to 12 mm into the brain.

12. An instrument according to any one of claims 9 to 11 wherein an attachment member is also provided at the distal end of the elongate shaft, the attachment member being releasably engageable with an associated skull mount.

13. An instrument according to any one of claims 9 to 12 wherein a plurality of scale markings are provided on the elongate shaft.

17. A method for aligning a skull mount relative to a hole formed in a subject'"'"'s skull, the skull mount comprising an alignment guide defining an alignment axis along which neurosurgical instruments can be passed, the method comprising the step of (i) using a stereoguide to align said alignment axis with a predetermined axis of insertion.

18. A method according to claim 17 wherein step (i) comprises the step of using a stereoguide that forms part of a stereotactic frame that is mounted to the subject'"'"'s skull.

19. A method according to claim 17 wherein step (i) is preceded by a step of configuring the stereoguide to guide neurosurgical instruments along the predetermined axis of insertion.

20. A method according to claim 17 wherein step (i) is preceded by the step of determining the axis of insertion along which neurosurgical instruments are to be guided to a desired target in the brain parenchyma.

21. A method according to claim 17 in which step (i) comprises using the stereoguide to guide a neurosurgical alignment instrument along the predetermined axis of insertion, the neurosurgical alignment instrument comprising an elongate shaft and an element protruding from the distal end thereof, wherein step (i) comprises bringing the protruding element of the neurosurgical alignment instrument into engagement with the alignment guide of the skull mount, thereby aligning the alignment axis of the skull mount with the predetermined axis of insertion.

22. A method according to claim 21 in which the distal end of the protruding element of the neurosurgical alignment instrument is arranged to pass through the alignment guide of the skull mount, wherein step (i) comprises forcing the distal end of the protruding element through the subject'"'"'s cortex.

23. A method according to claim 21 wherein step (i) comprises using the neurosurgical alignment instrument to carry a skull mount along the axis of insertion and into engagement with the hole formed in the subjects skull.

24. A method according to claim 17 comprising the step (ii) of fixing the orientation of the alignment axis of the alignment guide of the skull mount after step (i) has been performed.

25. A method according to claim 24 comprising the step (iii) of using the stereoguide to pass a guide wire through the alignment guide of the skull mount and along the predetermined axis of insertion into the brain parenchyma.

26. A method according to claim 25 wherein step (iii) comprises passing a guide wire inserted into a guide tube through the alignment guide of the skull mount and along the predetermined axis of insertion into the brain parenchyma.

27. A method according to claim 26 comprising the step (iv) of withdrawing the guide wire from the subject whilst leaving the guide tube in situ.

28. A method according to claim 27 comprising the step (v) of inserting at least one of an intraparenchymal catheter and an intraparenchymal electrode into the brain parenchyma through the guide tube.

29. A method according to claim 17 in which step (i) is preceded by the step of using a drill bit to drill a hole in the skull of the subject, wherein the stereoguide is used to pass the drill bit along the predetermined axis of insertion into contact with the subject'"'"'s skull.