INTERVENTION GUIDANCE DEVICE

Abstract

A guidance device for guidance of surgical interventions on a patient, the surgical interventions requiring an intervention device to surgically enter the body and be directed through body tissues to a target site within the patient's head, the guidance device comprising: a guide piece 4 for guiding the intervention device and directing it to the target site within the patient's head; a mouthpiece 2 arranged to anchor the device in a fixed orientation relative to the patient's upper jaw or lower jaw; and a targeted or targetable mounting 6 supporting the guide piece on the mouthpiece, the mounting 6 being for directing the guide piece 4 in a desired orientation relative to the mouthpiece 2 to thereby direct the intervention device through body tissues to the target site in the patient's head.

Claims

1. A guidance device for guidance of surgical interventions on a patient, the surgical interventions requiring an intervention device to surgically enter the body and be directed through body tissues to a target site within the patient's head, the guidance device comprising: a guide piece for guiding the intervention device and directing it to the target site within the patient's head; a mouthpiece arranged to anchor the device in a fixed orientation relative to the patient's upper jaw or lower jaw; and a targeted or targetable mounting supporting the guide piece on the mouthpiece, the mounting being for directing the guide piece in a desired orientation relative to the mouthpiece to thereby direct the intervention device through body tissues to the target site in the patient's head.

2. A device as claimed in claim 1, wherein the mouthpiece is arranged to be mounted to the patient's upper or lower teeth in order to thereby anchor the device to the upper or lower jaw.

3. A device as claimed in claim 1, wherein the mouthpiece is arranged to be mounted to the gums and/or the roof of the mouth.

4. A device as claimed in claim 1, comprising a mouldable inner material for conforming to the patient's teeth, gums and/or roof of the mouth.

5. A device as claimed in claim 1, wherein the mouthpiece is fixed to the teeth by a mechanical fixing such as a clamp.

6. A device as claimed in claim 1, wherein the mounting is an adjustable coupling that is adjustable so that it can point towards any target site inside of the patient's face/head.

7. A device as claimed in claim 6, wherein the adjustable coupling includes one or more articulated joints allowing for rotation and/or sliding motion of one or more lever arms.

8. A device as claimed in claim 6, wherein the adjustable coupling is lockable so that it may be fixed in place once the guide piece is in the desired orientation.

9. A device as claimed in claim 1, wherein the mounting is a targeted mounting that is tailor-made for the patient to target a specific target site and a specific approach based on the patient's anatomy.

10. A device as claimed in claim 9, wherein the mounting is arranged for guiding the intervention device toward the SPG via a transpalatine approach.

11. A device as claimed in claim 1, wherein the guide piece takes the form of a hollow tube.

12. A device as claimed in claim 1, wherein the guidance device incorporates a navigational array or an anchor for a navigational array.

13. A device as claimed in claim 12, wherein the navigational array is integrated in the mouthpiece.

14. A device as claimed in claim 1, wherein the device includes an indicator for providing a warning of undesirable movement.

15. A device as claimed in claim 14, wherein the guidance device comprises a light source for pointing at the patient.

16. The device as claimed in claim 14, wherein the device has a camera attached that can register an inadvertent movement.

17. A device as claimed in claim 1, including a patient localiser mounted on the patient's head.

18. A device as claimed in claim 1, comprising a patient localiser with a light source that can be directed towards a target on the mouthpiece.

19. A device as claimed in claim 1, comprising a proximal piece for holding a proximal end of an intervention device used with the guidance device, the proximal piece being arranged to allow for measurement of and/or control of the depth of insertion of an intervention device into the patient.

20. A device as claimed in claim 1, where the device is a single-use device intended to be disposed of after use.

21. A system for guided surgical interventions comprising a guidance device as claimed in claim 1 along with an intervention device.

22. A system as claimed in claim 21, wherein the intervention device includes a navigation array, such as a localiser, in order to allow for guided placement of the intervention device, such as guided insertion to a required depth.

23. The system as claimed in claim 21, wherein the intervention device is a trackable needle, for example an electromagnetic needle, that allows for the operator to track the location of the needle within the body.

24. A method of targeting an intervention device for later surgical intervention on the body, where the device comprises a guide piece for guiding an intervention device; a mouthpiece arranged to anchor the device in a fixed orientation relative to the patient's upper jaw; and a mounting supporting the guide piece on the mouthpiece, the method comprising: non-surgically attaching the mouthpiece of the device to the patient's upper jaw or lower jaw; determining a desired orientation for a guide piece of the device which will enable the guide piece to later guide the intervention device to surgically enter the body and be directed through body tissues to a target site within the patient's head; and setting the orientation of the guide piece relative to the mouthpiece by means of a tailor made mounting or a targetable mounting so that the guide piece is in the desired orientation.

25. A method as claimed in claim 24, comprising use of the guidance device or system of claim 1.

26. A method as claimed in claim 24, wherein the mouthpiece is attached to the patient's jaw by securing it to the patient's teeth.

27. A method as claimed in claim 24, wherein the mouthpiece is mounted to the gums and/or the roof of the mouth.

28. A method as claimed in claim 24 wherein a targetable mounting and the method includes fixing the guide piece in place once it has been adjusted to the desired orientation.

29. A method as claimed in claim 24, being used for a surgical intervention on the body wherein the method comprises use of a needle as the intervention device and guided injection of a pharmacological substance into the body at the target site.

30. A method as claimed in claim 24, being used for a surgical intervention on the body wherein the method comprises navigated insertion of an intervention device toward the SPG along the lateral approach.

31. A method as claimed in claim 24, being used for a surgical intervention on the body wherein the method comprises navigated insertion of an intervention device toward the SPG along the transpalatine approach.

32. A method as claimed in claim 24, being used for a surgical intervention on the body wherein the method comprises navigated insertion of an intervention device toward the OG via a transoral approach or lateral approach.

33. A method as claimed in claim 24, being used for a surgical intervention on the body wherein the method comprises navigated insertion of an intervention device toward the trigeminal ganglion via a percutaneous approach or a transoral approach.

34. A computer programme product containing instructions that when executed will configure a computer guided surgery navigation system to determine a required orientation of the guide piece of the guidance device or system of claim 1 when the guidance device has been secured to the patient's jaw via the mouthpiece.

Description

[0088] Certain preferred embodiments will now be described by way of example only and with reference to the accompanying drawings in which:

[0089] FIG. 1 shows a guidance device in a first perspective view;

[0090] FIG. 2 shows the guidance device of FIG. 1 in a second perspective view;

[0091] FIGS. 3a and b show the location of the SPG in the head with an intervention device shown approaching the SPG laterally;

[0092] FIG. 4 shows the transnasal approach with an intervention device having an angled tip;

[0093] FIGS. 5a and b show a lateral approach to the OG;

[0094] FIG. 6 shows a transnasal approach to the OG, this approach being defined by a straight line;

[0095] FIG. 7 shows an alternative guidance device in perspective view; and

[0096] FIG. 8 shows the device of FIG. 7 viewed from above.

[0097] As shown in FIGS. 1 and 2 a guidance device is provided with a mouthpiece 2, a guide piece 4 and an adjustable coupling 6. The mouthpiece 2 in this embodiment has a shape similar to a gum shield, and can be attached to the patient's upper teeth via dental adhesive products, for example. The guide piece 4 has optical markers 8 forming a navigational array for use with an image guided navigation system. It will be understood that other forms of markers could be used. The guide piece 4 includes a lumen/guide tube 10 to which the navigational array 8 is attached. The lumen 10 can be aligned with a desired orientation so that an intervention device, such as a needle for example, can be inserted along the lumen toward a target site in the patient's head. The target site can be any location that is fixed relative to the upper jaw, for example it may be the SPG targeted via a lateral approach. The adjustable coupling 6 has clamps 12 that releasably attach the lumen 10 to the mouthpiece 2 via two rods 14. It will be understood that there may be differing numbers of clamps 12 and rods 14. Alternative designs of adjustable coupling 6 are also possible. Provided an adjustable and preferably lockable movement of the lumen 10 can be permitted then any type of joint can be used in the adjustable coupling 6.

[0098] With this embodiment the mouthpiece is first fixed to the patient via the patient's teeth. Then the clamps 12 are loosened to permit a sliding and rotating motion of the rods 12 in order to allow adjustment of the lumen 10 into a desired orientation. Computer guided surgery systems can be used to guide the adjustment process. When the lumen 10 is at the desired angulation and location then the clamps 12 can be tightened to lock the mechanism. The interventionist may then carry out the required intervention with precision, since even if the patient moves the guide piece 4 will remain in the required orientation relative to the target site.

[0099] As described above, there may be a light source of a camera (not shown) attached to the device, preferably at the mouthpiece 2, in order to provide a visible alert of undesired movement of the guide piece 4 and/or mouthpiece 2 away from the desired orientation. The device can also include a screen (not shown) on a tablet or smart phone, with the screen being arranged to show guidance information from a computer navigation system.

[0100] FIGS. 7 and 8 show another guidance device. This has a similar mouthpiece 2, but the guide piece 4 has a different design. This example uses a tailored guide piece 4, where the orientation of the guide piece 4 is set based on imaging data showing the patient's anatomy. In this example the guide piece 4 is arranged to target the SPG via a transpalatine approach. The mouthpiece 2 is for fixation to the patient's upper teeth to thereby fix the device (and the guide piece 4) relative to the upper jaw. The device is then fixed relative to the SPG and also to the transpalatine canal. The guide piece 4 has a proximal end 15 that will protrude out of the patient's mouth and can receive an intervention device, for example a needle. The guide piece 4 also has a distal end 16 that will be within the patient's mouth and has an orientation specifically tailored to the patient in order to direct the intervention device along the palatine canal toward the SPG.

[0101] It will be understood that either of the example devices could be readily adapted for mounting to the lower teeth in order to hence allow for targeting of sites that are fixed relative to the lower jaw.

[0102] The proposed device leads to numerous advantages: [0103] It is not necessary to fixate the patient head and this enables procedures formerly performed under sedation/general anaesthesia to be performed on a conscious patient, leading to procedures with less complication and lower cost. [0104] The guide is attached to the patient without fixating the head, and will despite movement of the head point directly towards the target structure. The interventionist therefore can use both hands to handle the working device, syringe, pharmacological substances etc. [0105] The procedures will be much easier to perform and therefore within the reach of physicians and GPs, making the procedure more available to patients. [0106] The light source and/or camera will warn the interventionist if the device inadvertently moves relative to the target, making procedures more accurate and safer for the patient. [0107] The screen on device will make the image guided procedure more user-friendly and lower the threshold for performing the procedure for professionals not trained for conventional image guided procedure.

[0108] The devices described above makes it safer to use a lateral or transpalatine approach targeting the SPG, as well as other procedures (for example, targeting the OG), significantly lowering the risk of complications such as tissue destruction of adjacent structures by the very instrument at use or by adverse events due to misjudged placement of the needle while injecting the pharmacological substance. At the same time the positioning of the injection will be highly accurate, making it feasible to use small volumes with minimal possibilities of diffusion into adjacent structures. Such a precision also ensures optimal delivery of the pharmacological substances and therefore optimal treatment effect.

[0109] In the case of electromagnetic navigation, which can be used as an alternative or in addition to optical navigation, a coil can be embedded in the guide piece 4.

[0110] A possible advantageous use of the device is the injection of neuroinhibitory substances such as botulinum toxin in close proximity to the SPG or OG. Note that the injection device should not penetrate the SPG or OG. The injection is achieved in order to treat or prevent headache and may be achieved without damage to surrounding critical structures within the head. A neuroinhibitor is defined as any substance that affects transmission in a neural structure, resulting in any change of transmission, which may decrease or increase the neural activity. The neuroinhibitory substance is preferably a neurotoxin.

[0111] By delivery of the active substance in close proximity (proximally) to the sphenopalatine ganglion or otic ganglion means that the botulinum toxin or other neuroinhibitory substance in question is delivered so that it causes the desired technical effect, e.g. the prevention of treatment of headache etc. Ideally therefore the neuroinhibitory substance is injected to within 5 mm of the SPG or OG, preferably within 4 mm, such as within 3 mm, especially within 2 mm. Ideally injection of the active ingredient takes place 2 mm or less form the target SPG or OG.

[0112] The injection of the neuroinhibitor occurs laterally, transnasally, transorally or via the transpalatine approach in order to ensure that a safe, close injection of the neuroinhibitor is achieved. The terms laterally, infrazygomatically, transnasally and transorally are terms of this art.

[0113] The term infrazygomatic therefore requires that the injection takes place inferior to the zygomatic arch on either side of the mandibula, typically anterior or through the mandibular notch.

[0114] The term transnasally defines an injection route which involves advancing the needle through the nasal cavity. Targeting the SPG this route will further violate the lateroposterior boundary of the nasal cavity, constituting the medial boundary of the SF.

[0115] The preferred transoral approach is for the OG and hence includes advancing medial to the mandibular ramus and lateral to the midline of the head, in order to enter the infratemporal fossa and hence target the OG.

[0116] Targeting the OG transnasally involves advancing through the maxillary ostium and the maxillary sinus, violating the back wall of the maxillary sinus, advancing on the lateral aspect of the lateral pterygoid plate. The OG is located in the infratemporal fossa, the SPG in the sphenopalatine fossa.

[0117] It is preferably the case that access to the SPG or OG from the outside of the body is achieved laterally or transnasally by insertion of the injection device such that the device defines a straight line between SPG or OG (or more specifically the point proximal to the SPG and OG where active substance release will occur) and the point at which the external skin or mucosa is penetrated. This is illustrated in FIGS. 13, 15 and 16. FIG. 14 shows an alternative preferred approach where the end piece of the device has a curved tip enabling the needle to be directed toward the SPG or OG at an angle from the main axis of the lumen. The device punctures the wall of the nasal cavity at puncture site 50 and the angled tip directs the needle toward the target site.

[0118] The lateral approach therefore allows the injection device to pass through the skin and then soft tissue to the SPG or OG. That can be achieved in a straight line and hence with a straight injection device. That means that the injection can be targeted very accurately in close proximity to the SPG or OG. This method of administration allows application under local anaesthetic.

[0119] Where the injection takes place transnasally the route involves passing through the nasal mucosa and the sphenopalatine foramen or the perpendicular plate of the palatine bone to reach the SPG. Injection is not therefore lateral (via the cheek) but preferably involves a straight line from the injection point to the SPG. Transnasal route to reach the OG involves advancing through the maxillary ostium and the maxillary sinus, violating the back wall of the maxillary sinus, advancing on the lateral aspect of the lateral pterygoid plate. This involves a straight line from the injection site to the OG. These methods may require general anaesthesia.

[0120] Using the transpalatine approach, as the guide piece 4 is accurately targeted toward the inferior opening of the palatine canal then high-precision interventions targeting the SPG are possible, unlike in the prior art. The oral cavity communicates with the sphenopalatine fossa through the greater traspalatinal canal. The inferior opening is situated on the medial side of the second molar and the length of the canal is on average 25 mm. The canal transmits the descending palatine artery and vein, and the greater and lesser palatine nerves.

[0121] The injection described above can be used in the treatment or prevention of headaches, in particular any kind of primary headache or secondary headache. The treatment or prevention may relate therefore to cluster headaches, migraine, tension-type headache, short lasting unilateral neuralgiform headache with conjunctival injection and tearing/cranial autonomic features (SUNCT/SUNA), hemicrania continua or paroxysmal hemicrania.

[0122] Paroxysmal hemicrania is a primary headache disorder involving frequent attacks of unilateral, peri-orbital and temporal pain typically lasting less than 30 minutes. The pain can be associated with conjunctival injection, lacrimation, nasal congestion, rhinorrhea, ptosis and eyelid edema.

[0123] SUNCT/SUNA is a primary headache disorder characterized by multiple attacks of unilateral, peri-orbital and temporal pain typically lasting less than 2 minutes. The pain is associated with conjunctival injection, lacrimation, nasal congestion, rhinorrhea, and eyelid edema. This headache may be associated with trigeminal neuralgia.

[0124] Hemicrania continua is a primary headache disorder characterized by a strictly unilateral headache responsive to Indomethacin. The pain is associated with conjunctival injection, lacrimation, nasal congestion, rhinorrhea, ptosis, and eyelid edema.

[0125] It will be appreciated that the term treatment here refers to reduction in pain experienced by a patient and/or a reduction in the frequency in which headache occurs. The term prevention means preventing headaches occurring, e.g. as frequently as before.

[0126] The neuroinhibitory substance is one which is capable of preventing or treating headache when administered in close proximity to the SPG or OG. Suitable inhibitors include Botulinum toxin, Tetanus neurotoxin, (which is produced by Clostridium tetani), Staphylococcal alpha-toxin, and acylpolyamine toxins (e.g. AR636 and AG489).

[0127] In general the therapeutic modality used to treat and/or prevent headache is a presynaptic neurotoxin. “Presynaptic neurotoxin” as used herein refers to those neurotoxins and their derivatives which are known to produce localized, reversible flaccid paralysis of musculature in mammals which does not result in degeneration of muscle or nervous tissue. It is preferred however if the inhibitor is botulinum toxin. This is a protein and neurotoxin produced by the bacterium Clostridium botulinum and is commercially available. It is preferred if the botulinum toxin is of types A, B, C, D, E, F or G, such as Botulinum toxin type A. Botulinum toxin may for example be administered in the manner and form described in U.S. Pat. No. 7,981,433 The frequency of the injections needed may be every 3 to 8 months but will be patient dependent.

[0128] Whilst the method described above is in relation to the administration of neuroinhibitory substances such as botulinium toxin, the method of injection and device discussed here can be used for the injection of other active substances such as local anaesthetics (e.g. lidocaine or marcain) and corticosteroids (e.g. triamcinolone). The method and device may be used to inject a local anaesthetic or corticosteroid for use in a method for treating or preventing headache, rhinitis, rhinosinusitis, Frey syndrome or hypersecretion of tears/lacrimation comprising injecting said substance in close proximity to the sphenopalatine ganglion or otic ganglion wherein an injection device comprising said substance is brought into close proximity to the sphenopalatine ganglion or otic ganglion by inserting said injection device into the patient transnasally or laterally and the substance injected in close proximity to the SPG or OG.

[0129] Various example procedures that can advantageously make use of the guidance device described above are set out below and FIGS. 3a through 6 illustrate the locations of the SPG and OG along with possible approaches for interventions on the SPG or OG as discussed above.

EXAMPLE 1

[0130] A female patient with refractory hemicrania continua was treated via injection of Botox around the SPG. Due to an occipital neurostimulator MRI was contraindicated and identification of SPG on MRI was not possible. Preoperatively the calculated position of the SPG was marked on a CT scan with 1 mm slides. On the navigation planning system a preplanned puncture site and trajectory was made. On the symptomatic side a navigable needle guide was advanced through the sphenopalatine foramen and towards the SPG. The needle was passed through the guide and the tip of the needle was confirmed to be 1 mm from the SPG by the navigation system while 75 IU botulinum toxin type A was injected.

[0131] Over a period of two months prior to the treatment the patient had an average headache intensity of 8.1 (scale 1-10) and normally experienced from one to four headache attacks daily. From 4 to 10 weeks after the treatment the patient had not a single attack during the whole period and the average headache intensity was 6.3. The patient also did not experience any complication during 4 months follow-up.

EXAMPLE 2

[0132] The patient was a male that presented with a prevertebral mass close to the atlas (C1) seen on MRI. He had formerly been treated for pulmonary cancer histologically classified as adenocarcinoma. After a clinical assessment it was concluded that the tumor was not available for conventional procedures for a histological diagnosis. Using a navigable guide with an optical navigation system and a transoral approach it was possible to do a fine needle biopsy of the tumor deep in the neck to confirm the suspicion of a pulmonary metastasis.

EXAMPLE 3

[0133] A female patient with refractory chronic cluster headache was treated via injection of lidocaine around the OG. Preoperatively the calculated position of the OG was marked on a CT scan with 1 mm slides. On the navigation planning system a pre-planned puncture site and trajectory was made. On the symptomatic side a navigable needle guide was advanced through the maxillary ostium and the back wall of the maxillary sinus, and then at the lateral aspects of the lateral pterygoid plate to the OG. 5 ml of lidocaine 20 mg/ml was injected. The patient had a short relief of the headache as expected using short-acting local anaesthetic.

EXAMPLE APPLICATIONS

[0134] The advantages for interventions targeting the SPG will also arise when using the device for IGS in other parts of the patient that are fixed relative to the upper jaw for indications such as injections, biopsies, punctures, aspiration, ablation therapy, and for positioning of electrodes, catheters, radioactive seeds and implants. The design of the intervention device use with the guidance device can be varied as required. For example, it may be advantageous to use a similar device with an alternative tip design or a different length of end piece, depending on the characteristics of the target site, the approach available and the procedure that is to be carried out. The guidance device may thus be utilised for procedures to address numerous medical conditions. Procedures that the guidance device can be used for include: [0135] Injections [0136] Any pharmacological substance [0137] Neuroexcitatory agent [0138] Neuroinhibitory agents [0139] Botulinum toxin, any type [0140] Staphylococcal alpha-toxin [0141] Tetanus neurotoxin [0142] Acylpolyamine toxins [0143] Core needle biopsy and fine needle biopsy [0144] Head and neck area [0145] Intracranially [0146] Extracranially [0147] Retropharyngeal space [0148] Parapharyngeal space [0149] Skull base [0150] Deep regions of the face [0151] Any region of the face [0152] In the vicinity of the columna [0153] In the vicinity of bone [0154] Puncture and aspiration [0155] Evacuation of cystic structures and fluidic compartment for diagnosis and therapy of the head and neck region [0156] Ablation therapy [0157] Any nerve or neural structure, intracranially and extracranially [0158] Ablation of normal tissue to reduce volume and/or increase stiffness [0159] Ablation of tumour tissue [0160] Positioning of electrodes, catheters, implants, electrophysiological measurements, radioactive seeds [0161] Endoscopy and/or pointer procedures [0162] Flexible or rigid endoscope may be attached to the device [0163] Any procedure in an open cavity that requires endoscope or pointer [0164] Paranasal sinusis [0165] Nasal cavity [0166] Farynx [0167] Larynx [0168] Facet blocks [0169] The device can be used in the treatment of conditions including: [0170] Headache [0171] Migraine [0172] Cluster headache [0173] Tension-type headache [0174] Trigeminal Autonomic Headache [0175] SUNCT [0176] Hemicrania Continua [0177] Paroxysmal hemicrania [0178] Any kind of primary headache [0179] Any kind of secondary headache [0180] Rhinitis [0181] Allergic rhinitis [0182] Vasomotor rhinitis [0183] Rhinitis medicamentosa [0184] Polypous rhinitis [0185] Any kind of non-structural rhinitis [0186] Rhinosinusitis [0187] Without polyps [0188] With polyps [0189] Any kind of rhinosinusitis [0190] Hypersecretion of tears/excessive lacrimation [0191] Any disease with hypersecretion of tears [0192] Frey syndrome/auriculotemporal syndrome/gustatory sweating [0193] Tinnitus [0194] Objective tinnitus [0195] Subjective tinnitus [0196] Neck and back pain/syndromes [0197] Spinal nerve/root blocks [0198] Spinal taps [0199] Post traumatic neck pain [0200] Cervical disc disorders [0201] Myofacial neck pain [0202] Rheumatic and arthritic disorders [0203] Neuromuscular disorders [0204] Facial pain [0205] orofacial pain disorders [0206] myofascial pain disorders [0207] temporomandibular joint disorders [0208] neuropathic orofacial pain [0209] trigeminal neuralgia [0210] oral motor disorders

[0211] Whilst the indications and examples above primarily relate to conditions of the human body the device can of course also be utilised for interventions on the animal body.