Cervical Cooled-RF Training Presentation

Transcription

1 Cervical Cooled-RF Training Presentation

2 AGENDA Patient Selection Anatomy Overview Technique Diagnostic Block Cooled-RF Precautions Summary

3 Patient Selection

4 Cervical Zygapophyseal Joint Pain Cervical zygapophyseal joints are a common source of neck pain Prevalence: 36-62% of patients with neck pain attending pain clinics 1 Cervical z-joints are injured in whiplash injury Loads caused flexion rotation, facet separation, and anterior translation of the upper facet relative to the lower. 2 Cervical z-joints are common source of pain in whiplash injuries Speldewinde et al., 2001; Lord et al., 1996; Yin et al., 2008; Manchikanti et al., 2002, 2004, Aprill et al Ivancic et al Bogduk 2003, 2011

5 Patient Selection Diagnosis Chronic cervical axial (non-radicular) pain, nonresponsive to conservative therapy Greater than 80% pain relief from 2 separate medial branch blocks (no more than 0.3 ml injectate per block) Please see Instructions for Use for detailed information regarding proper use that includes indications and lists of warnings, precautions and contraindications

6 Contraindications Cardiac pacemakers In sensing mode, the pacemaker may interpret the RF signal as a heartbeat and may fail to pace the heart. Contact the pacemaker company to determine if the pacemaker should be converted to a fixed-rate pacing during the radiofrequency procedure. Evaluate the patient s pacing system after the procedure. Check the compatibility and safety of combinations of other physiological monitoring and electrical apparatus to be used on the patient in addition to the RF Generator. Spinal cord, deep brain, or other stimulator Contact the manufacturer to determine if the stimulator needs to be in the bipolar stimulation mode or in the OFF position. This procedure should be reconsidered in patients with any prior neurological deficit. General anesthesia. To allow for patient feedback and response during the procedure, it should be performed under local anesthesia. Systemic infection or local infection in area of the procedure. Blood coagulation disorders or anticoagulant use.

7 Clinical presentation of cervical z-joint pain Cervical facet pain has been replicated in normal individuals, when their cervical zygapophyseal joints were stimulated with intra-articular injections of contrast medium (Dwyer et al., 1990). o The following pain maps were obtained: Figure: A composite map depicting the characteristic distribution of pain emanating from the C2-3 to C6-7 zygapophyseal joints. (Lord et al., 1998 adapted from Dwyer et al., 1990) (Patterns of referred pain from the cervical zygapophyseal joints produced experimentally in normal volunteers)

8 Patient selection for cervical RF neurotomy Evaluate and treat symptomatic cervical stenosis or symptomatic cervical radiculopathy with SNR or ESI s. Clinically evaluate the role of the shoulder which is often a cause of cervical pain. Evaluate and treat pain of lumbar z-joint origin. C/S Axial imaging is typical standard of care MRI and/or CT scan Consider cervical flexion-extension radiographs. Low volume diagnostic medial branch blocks.

9 Cervical Radicular (Non-axial) Pain Patterns RF lesioning of the cervical medial branches is indicated for axial pain of z-joint origin, NOT for radicular pain.

10 Anatomy Overview

11 Cervical Z-Joint Anatomy Zygapophyseal joints: paired posterior diarthrodial joints from C2-S1 Innervation: 1-4 articular nerve branches derived from descending or ascending divisions of the medial branch of the dorsal primary ramus issuing from somatic nerves above and below the joint level Articular nerves issue from the MB in the posterior half of the articular pillar (lateral mass) The dorsal Cruveilhier plexus may provide additional sensory innervation to C2-4 z-joints issuing from the C1 dorsal ramus and the C2-4 medial branches.

12 Osseous Anatomy C1 and C2 vertebra are atypical C1 (atlas): 2 lateral masses connected by a short anterior and a longer posterior arch NO vertebral body Lateral masses form the inferior portion of the AO and superior AA joints. Maximum width: mm in males, mm in females Tip of the transverse process usually palpable between the mastoid process and ramus of the mandible C2 (axis): Acts as an axle for rotation of the atlas and head around the odontoid process (dens), which extends superiorly from the C2 vertebral body C2 dens is secured to C1 by several atlantoaxial ligaments Spinous process is large, with a bifid tip, and is concave inferiorly Standring, Gray s Anatomy 2005

13 Skeletal Anatomy C3 C6: The bone between the lamina and cervical pedicle is the lateral mass. Due to orientation, the short cervical pedicles are often superimposed over the vertebral body in lateral fluoroscopic view. Superior and inferior surfaces of the lateral mass are cartilaginous. Adjacent superior and inferior articular surfaces of adjacent vertebrae form the zygapophyseal (facet) joint Facet shape and orientation: Superior articular facets: flat and ovoid; directed superoposteriorly Inferior articular facets: directed inferoanteriorly C2-3 z-joint Lamina C4 Lateral mass C5 Body C6 Note C3-4 facets show 2 lucencies height of lateral mass is often asymmetrical. Requires adjustment of c-arm to visualize ipsilateral z-joint space.

14 Skeletal Anatomy C7: Most inferior cervical vertebra (vertebra prominens) Prominent non-bifid spinous process is palpable from the skin surface Attaches to the ligamentum nuchae and various muscles Large transverse processes: posterolateral to the transverse foramina Transverse foramen at C7 rarely transmits the vertebral artery (unlike C2-C6 vertebrae) May have transitional variation suggestive of thoracic vertebrae, including vestigial ribs Standring, 2005

15 The Vertebral Artery The V2 segment of the vertebral artery lies anterior to the lateral masses at C2-7 The vertebral artery in the V3 segment passes cephalad and laterally from the C2 foramen transversarium to the C1 foramen transversarium, then turns medially, passing across the dorsal ring of C1 posterior to the AO joint before turning cephalad to enter the foramen magnum. Avoid trouble: Direct all implements towards the lateral masses and generally below C1! C1 C2 Tubbs RS, et al. Surgical anatomy and quantitation of the branches of the V2 and V3 segments of the vertebral artery. J Neurosurg Spine 11:84-87, 2009.

16 General Scheme of the Cervical medial branches

17 Cervical Medial Branch Neuroanatomy Medial branches are about 1 mm diameter Arise from the posterior primary ramus, travel dorsally and inferiorly around the groove of the lateral mass Often divide into superficial and deep divisions medial branch or deep division issues the ascending and descending articular nerves posterior to the centroid of the lateral mass and underneath the semispinalis muscle insertions on the lateral masses superficial division runs through or posterior to the semispinalis to supply cutaneous ipsilateral paramedian sensation Suggested reading: Bogduk N. The clinical anatomy of the cervical dorsal rami. Spine 1982;7:

18 Cervical Medial Branch Neuroanatomy C3: Two divisions of the medial branch Deep division of medial branch innervates C3-4 z-joint (lateral) and upper half of C3 articular pillar Superficial division medial branch becomes the 3 rd occipital nerve (TON) and innervates C2-3 z-joint TON includes a contribution from the C2 medial branch C4 Lang J. Clinical anatomy of the cervical spine. Verlag 1993

19 Neuroanatomy Cervical Dorsal Ramus Medial Branches C4: slightly higher on the articular pillar than C5, upper 25% of pillar height, not higher than posterior corner of C4 SAP. AP, within the concavity of the articular pillar C5: runs transversely across the centroid of the articular pillar, variation +/- 20% of pillar height, within the concavity of the articular pillar C6: lateral, anywhere across the middle two quarters of the articular pillar. AP, within the concavity of the articular pillar, sometimes lateral to the convexity of the C5-6 z-joint C7: crossing the triangular SAP of C7 just above the transverse process

20 Exceptions to the anatomic rules At C3, the superficial division of the medial branch becomes the third occipital nerve (TON). A branch from the C3 MB can communicate with the C2 dorsal primary ramus. Sensation to the C2-3 facet can originate from the TON or from the C2-3 communicating branches. At C7, a slip of muscle may extend laterally, displacing the MB laterally, necessitating an additional slightly lateral lesion at this level. by Yin (Pain Medicine 2008) which may be important in C1-2 joint pain.

21 Technique

22 Current Treatment (ISIS Guidance) Patient either prone or in lateral position with target side uppermost Two stages, involving an oblique insertion and a sagittal insertion of the electrode This approach targets the nerve where it lies anterolateral and lateral to the articular pillar, and is intended to increase the length of the nerve that is coagulated. A single lesion method is associated with more rapid recovery and shorter duration of relief. It is recommended that the oblique insertion be executed first, as it is the more difficult stage. This is because of the unconventional aspects involved in recognizing landmarks The sagittal pass can be expeditiously completed This technique has changed little in two decades. Execution of this technique is time consuming and tedious. Outcomes are limited by variation in the precise location of the medial branch and the ability to place lesions parallel to and fully encompassing the target MB. Figure: Cross section view through C5 vertebra of technique sued to coagulate the medial branch of a cervical dorsal ramus (Lord et al., 1996)

23 Indication for Use Indication The KIMBERLY-CLARK* COOLED RADIOFREQUENCY KIT, in combination with the KIMBERLY-CLARK* Radiofrequency (RF) Generator (PMG- 115-TD/PMG-230-TD) (formerly Baylis Pain Management Generator) is indicated for use to create RF lesions in nervous tissue Please see Instructions for Use for detailed information regarding proper use that includes indications and lists of warnings, precautions and contraindications

24 Cooled Application Internally Cooled 2 mm Active Electrode Oblate spheroid Sphere is flattened in the axial direction 4-6 mm diameter Lesion settings: 60 C for 2:30 min

25 RF Lesion Criteria Increase probability of ablating medial branch Lesion must encompass variability of nerve path Target a known landmark easily visualized with fluoroscopy Similar to lumbar and cervical convention: Ablate medial branch before ramification (into z-joint, muscular and cutaneous branches) Heating of sensitive structures must be avoided by understanding the geometry of the thermal lesion Nerve root Vertebral artery

26 Lesion Characterization Size: 4-6mm Shape: Oblate Spheroid

27 Adapted from Fig 3.3 of Chua Thesis 1994

28 Procedural Technique Technique is equivalent to the Cervical Medial Branch Block procedure as described in ISIS Guidelines. Cervical Medial Branch Blocks Technique for third occipital nerve block

29 Diagnostic Cervical Medial Branch Block Lateral approach, patient lies on their side with painful side upwards Stabilize position with foam bolster, pillow or sandbag. Obtain true lateral view. Superimposition of articular pillars silhouettes (tilting beam cranial-caudal splits the superimposition) Move C-arm or table so target point is in the center of the beam to reduce parallax error Target: C3-C6 Centroid of the articular pillar, same segmental number as the target nerve. Target: C7 Apex of the C7 SAP, just above the transverse process Target: TON - three target points lie on an axial line that bisects the C2 and C3 articular pillars. The intersection of the axial line with a transverse line through 1) the apex of the C3 SAP, 2) tangential to the bottom of the C2-3 intervertebral foramen, 3) midway between the previous. *Bogduk, N. (ed.): Practice Guidelines Spinal Diagnostic & Treatment Procedures. International Spine Intervention Society, San Francisco, CA, USA, 2004.

30 C3-C6 Medial Branch Block Technique Identify centroid of the subject lateral mass. This may be used as a target. Select skin entry point overlying the target point avoiding superficial veins, if possible. If possible, avoid piercing the sternocleidomastoid muscle, as subsequent rotation of the patients head will pull the needle off course Align needle coaxially Insert needle through the skin and neck muscles, deep enough to prevent it from swaying if released. Check position and orientation to ensure it overlies the target point. Tolerable error should be no greater than the middle half of the area of the articular pillar Progressively insert toward target point and contact bone. Inject ml local anesthetic

31 TON Block Tolerable error zone is a rectangular area bounded by the anterior edge of the C3 SAP, upper and lower lines perpendicular passing posteriorly from the apex of the SAP and from the bottom of the C2-3 intervertebral foramen, and posterior line through the posterior edge of the IAP. Needle inserted towards the middle of the three target points Progressively insert needle to target point After first target point, the needle may be readjusted to the other target points. The three target points are situated at the intersections of the lines. (ISIS pp125b)

32 C7 Medial Branch Tolerable insertion zone should be no greater than the triangular silhouette of the C7 SAP Place needle at apex of C7 SAP Confirm placement with A-P view. Needle tip lies right against the lateral margin of the SAP. 0.3mL at target point, then withdraw 4mm and deliver a second aliquot of 0.3mL. (this is due to the variation in the C7 medial branch. Instead of running along the bone, it is displaced by a bundle of the semispinalis capitis.

33 Comparison of Cooled and conventional RFL CerviCool* Larger lesion compensates for variable course of MB/TON Single lesion has potential to shorten procedure time Allows user choice of true lateral or posterolateral technique Can use anatomic placement 2 Hz stimulation is optional Fewer steps than conventional C8 RF lesion technique Conventional RFL Lesion size depends upon needle gauge Typically requires multiple needle placements, multiple heating cycles Posterolateral approach only Anatomic placement is possible, but small lesion size suggests improved nerve localization using 2 Hz stimulation

34 Posterior Approach Cervical Medial Branch Patient prone position Placement of a marker needle Obtain lateral view, identify the center of the neural arch at the target level Insert marker needle and direct under tunnel vision to contact the bone Placement of Introducer Rotate to A-P view, and identify the waist of the articular pillar Insert introducer under AP guidance to marker needle. The introducer needle should lie at the waist of the vertebra in the AP view, just posterior to the foramen (foraminal view)

35 Cooled-RF Posterior approach for C8 RFL Technique identical to Thoracool C8 MB runs across the cephalad aspect of T1 transverse process just medial to the inflection point AP View Probe cephalad to transverse process just medial to inflection point Contralateral oblique probe just cephalad to transverse process Contralateral oblique transverse process outlined (obscured by clavicle)

36 Cooled RFL Posterior approach AP View Lateral View

37 Cooled-RF technique Lateral approach Patient in lateral position with sterile prep and drape True lateral fluoroscopic view of target lateral mass Identify centroid of lateral mass Inject local anesthetic and pre-stick skin with 18/19 gauge needle, as desired Insert trocar to contact centroid. Stabilize trocar, maintaining depth and orientation. Remove stylet and inject 1-2 ml local anesthetic Insert Cervicool probe into trocar, maintaining depth and orientation Verify Cervicool probe location and lesion at 60 degrees C x 150 seconds (2.5 mins) Remove trocar and Cervicool probe, repeat at additional levels as indicated.

38 C7 Cooled-RF Lateral Approach AP view Probe 2 mm off of lateral aspect of C7 SAP points to notch Lateral view Probe appears at apex of C7 SAP but is just above transverse process Contralateral oblique Probe tip posterior to pedicle. Adequately far from neural foramen

39 Cooled-RF Lateral approach technique for 3 rd Occipital N./C3 RFL C3 MB Just above the centroid of the lateral mass of C3 At upper portion of lateral concavity of the C3 lateral mass. NOTE: Probe tip is 2 mm from bone surface. 3 rd occipital n. Across the C2-3 facet joint space DO NOT ENTER THE JOINT SPACE If you enter the joint, withdraw and move 1-2 mm cephalad onto C2

40 Cooled-RF Lateral approach technique for C4 RFL Probe tip placed at or minimally (1-2 mm) above the centroid of the C4 lateral mass. 2 mm gap Correct probe tip position divides lateral mass into two equal anterior and posterior halves. Probe tip is 2 mm off of bone surface on AP view C6 technique is identical at or 1-2 mm above the centroid. C5 is similar, but directly at the centroid.

41 Precautions

42 Precautions The Vertebral Artery - Avoid trouble: Direct all implements towards the lateral masses and generally below C1! Dropped Head Syndrome Following Multilevel Cervical Radiofrequency Ablation: A Case Report. Stoker GE, Buchowski JM, Kelly MP. Department of Orthopaedic Surgery, Washington University School of Medicine, Saint Louis, Missouri. STUDY DESIGN:: Case report. OBJECTIVE:: To describe a serious complication of multilevel radiofrequency ablation (RFA) of the cervical spine. SUMMARY OF BACKGROUND DATA:: Percutaneous RFA is an accepted nonoperative modality for the treatment of neck pain. When the procedure is performed according to established guidelines, serious adverse events are rare. METHODS:: The authors performed a clinical and radiographic case review. RESULTS:: A 54-year-old women presented with neck pain and weakness with cervical kyphosis. She had undergone left-sided RFA of the third occipital nerve and C2 to C4 facet joints eight weeks prior to presentation. The patient was incapable of extending her neck, though the deformity was passively correctable. Imaging revealed no lesions to which the kyphosis could be attributed. As the deformity progressed over the subsequent three months, surgery was recommended. An instrumented posterior fusion from C2 to T2 was performed with correction of the chin-on-chest deformity and improvement in the patient's axial neck pain. CONCLUSIONS:: Dropped head syndrome is a rare yet potentially debilitating complication of multilevel cervical RFA. PMID: [PubMed - as supplied by publisher]

43 Summary

44 CerviCool* Summary Reviewed the anatomy of the cervical spine with emphasis on the neuroanatomy of the cervical medial branches and TON. Diagnosis of cervical z-joint pain reviewed and proper technique for MBB/TON presented Cervicool RF technique compared with conventional RFL and typical Cervicool probe positions reviewed.

45 Thank You