Interventional Pain. Judith Dunipace MD Board certified in Anesthesiology, Pain Management and Hospice and Palliative Care

Transcription

1 Interventional Pain Judith Dunipace MD Board certified in Anesthesiology, Pain Management and Hospice and Palliative Care

2 IASP Definition of Pain Pain is an unpleasant sensory or emotional experience associated with actual or potential tissue damage or describes in terms of such damage.

3 Components of Pain Physiological Psychological Social / environmental

4 Acute vs. Chronic Signals ongoing or impending tissue damage associated with acute injury, inflammation or disease. Pain lasting beyond the duration of an injury in spite of therapy, inducing aspects of physical, emotional and psychological disease. Stops when source of pain ceases. Associated with degenerative and neurological changes, not always with identifiable pathology

5 Types of Pain Somatic Visceral Neuropathic Sympathetic Central Psychogenic

6 Anatomy of Pain Peripheral nociceptors Primary afferent neurons Dorsal Horn Secondary neurons Central pathways Descending pathways

7 Anatomy of Pain

8 Dorsal Horn Relay center for transmission and modulation of pain in the spinal cord Processing, windup and facilitation takes place in the DH Influenced by descending controls for the brain ( 5HT, NE) DH neurotransmitters include Substance P, EAA, Peptides Laminae II an III contain high concentrations of mu and delta receptors, as well as, alpha receptor Other receptors and transmitters Alpha 2, NMDA, Nitric oxide, Decending inhibitory neurotransmittes - Gaba, Glycine

9 Neurophysiology of pain Peripheral prostaglandins Dorsal horn substance P EAA peptides Central NE 5-HT Gaba Glycine

10 Rational for Interventional Pain Management Interrupt Pain Shut off wind up Prevent chronic pain Restore function

11 Treatment Strategies Modify source* Modify Interpretation Interrupt Pathways* Effect other contributing factors to pain

12 Anatomy of Spinal Injury Muscular / soft tissue Radicular / Neuropathic Discogenic Facet / Arthritic Vertebral

13 Interventional Therapies Local injections Epidural injections Selective nerve injection Discography Facet injections / SI joint injections Vertebralplasty / Kyphoplasty Sympathetic Injections Neuroablative procedures Neuraxial devices

14 Diagnostic versus Therapuetic Diagnostic Therapuetic Intended to identify to pain generator Often to isolate the exact location of injury for improved surgical outcome Intended to provide relief of pain and resolution of inflammation. To heal injury / alleviate symptoms To determine next therapy

15 Spinal Antatomy Cervical Thoracic Lumbar Sacral

16 Local injections Trigger point injection Joint injection Peripheral nerve injections

17 Epidural steroid injections Indication To suppress inflammation associated with disc herniation. To relieve radicular symptoms of nerve root irritation. In patients who have not responded to other conservative management In adjunct to other conservation management To identify pain generator prior to surgery

18 Disc Degeneration

19 Epidural steroid injections Translaminar Technique (cervical, thoracic, lumbar, caudal)

20 Epidural Steroid Transforaminal Epidural / Selective Nerve Injection (cervical, thoracic, lumbar, sacral)

21 Cervical Transforaminal Epidural

22 Lumbar Transforaminal Epidural

23 Thoracic Transforaminal

24 S1 transforaminal epidural

25 Epidural steroid efficacy Weiner and Frasier showed 46% success rate in achieving pain relief in the patient who did not go to surgery at 3 year follow up. Lutz et.al. reported 75% of patients studied showed greater than 50% relief at week follow up.

26 Efficacy Continued Reiw et Al. Showed in a controlled study that of patients treated with epidural steroid versus epidural local anesthetic significantly fewer required surgery. Vad et al. Compared outcomes of epidural steroid versus paraspinous saline injections. ESI 84% had >50% decrease in pain

27 Diagnostic Nerve injection Indication To Identify the exact source of pain Rational If the particular spinal nerve responsible for causing the patient s pain is anesthetized the symptoms should temporarily be relieved. Positive Predictive Value % in studies where patients went on to surgery.

28 Provocative Discography Indication To isolate the painful disc (diagnostic) To evaluate disc morphology (post disco CT) Predictive Value Useful predictor of surgical outcome Colhoun, McCall et al showed that of patients undergoing interbody fusion for LBP 89% had significant pain relief when discography revealed disc disease and concordant disc pain, while 52% with positive morphology only. Positive surgical outcome for LBP without discography 35%

29 Lumbar discography

30 Facet Anatomy (Zygapophysial joint)

31 Facet Injections Indications Chronic (not acute) axial spinal pain Osteoarthritis of the Facet joints Whiplash Prevalence of Facet Mediated pain Study by Schwarzer found in younger injured workers with low back pain the prevalence is less than 15% Schwarzer found 40% in non-injured, older, rhuematologic patients In US 80% of individuals over 40 years have lumbar spondylosis, of these 27-37% are asymptomatic

32 Facet Joint Injections Techniques Intraarticular (therapuetic) Medial branch injections (diagnostic) Rhizotomy (neuroablative)

33 Lumbar Medial Branch Block

34 Cervical Facet Pain

35 Rhizotomy / Radiofrequency Neurotomy Uses a insulated needle with an exposed tip High frequency electrical current heats the tip of the needle coagulating the surrounding tissues and target nerve

36 Cervical Medial Branch Block

37 Radiofrequency Electrode

38 Medial Branch Rhizotomy Indications The singular indication for radiofrequency medial branch neurotomy is the complete relief of a patients pain with diagnostic blocks of the target medial branches. Patient Selection Pain for 3 months Pain unresponsive to conservative therapy

39 Lumbar Rhizotomy

40 Cervical Medial Branch Anatomy

41 Cervical Rhizotomy

42 Cervical Rhizotomy

43 Efficacy Dreyfuss et al, Spine 2000 showed 60% of patients maintained 80% relief from their pain over 12 month period of time following rhizotomy Pain relief was corroborated with significant and sustained improvement in physical function.

44 Sacral Iliac Joint

45 Vertebralplasty / Kyphoplasty Indications Osteoporotic / traumatic or malignant vertebral compression fractures

46 Vertebralplasty Technique

47 SI joint injection Indication To establish source of back pain (diagnostic) in patients with suspected sacroilitis Diagnostic imaging is not reliable Physical findings may be indeterminant Pain over the sacral sulcus may refer to posterior / lateral thigh or groin

48 Sympathetic Ganglion blockade Stellate Celiac Lumbar sympathetic Hypogastic Plexus Ganglion Impar

49 Sympathetic Chain

50 Sympathetic Ganglion blockade Indications Sympathetically mediated pain, RSD, CRPS Neuropathic pain (shingles) Chronic visceral pain (pelvic, pancreatitis) Cancer pain Vascular insufficiency (Raynauds)

51 Complex Regional Pain Syndrome Chronic condition believed to result from dysfunction of the central and peripheral nervous system often trigger by injury. Characterized by pain out of proportion to that expected by the initial injury, getting worse over time not better. Associated with psuedomotor and vasomotor changes, allodynia, hypesthesia and hyperesthesia

52 Sympathetic Injection Techniques

53 Neuraxial Pain Devices Spinal cord stimulator Narcotic Infusion pumps

54 Spinal Cord Stimulation Indications Postlaminectomy syndrome CRSP Vascular Insuffincency

55 Spinal cord stimulation

56 Office Based Pain Incentives Fees Office Based interventional pain ASC / Hospital interventional pain MD yes yes Flouroscopy yes yes Radiologist no yes Facility no Yes $