Safety practices for interventional pain procedures: Facet interventions

These safety practices have been developed to highlight the important elements in the safe performance of interventional pain procedures. Adherence to these practices will help decrease the risk of preventable complications. For additional information about the indications and technical aspects that yield improved treatment outcomes, refer to the IPSIS Technical Manual and Atlas of Interventional Pain and Spine Procedures.

1. Intra-articular facet (zygapophysial) joint access/injection

Stephan Klessinger, MD, PhD; David C. Miller, MD, MA; Ameet Nagpal, MD, MS, MEd, MBA; Michael McKenna, MD; Yakov Vorobeychik, MD, PhD.

1.1. Personnel

• •Only physicians trained in the technique and interpretation of facet joint access and injection should perform this procedure.
• •Appropriately trained personnel are needed to operate the fluoroscopy unit or assist the physician.

1.2. Contraindications

1.2.1. Absolute

• •An active systemic infection or a localized infection within the procedural field
• •Uncooperative patient or inability to obtain informed consent
• •Allergy to medication(s) that cannot safely be omitted or mitigated by pre-treatment
• •Hypertensive emergency/urgency
• •Anatomical derangements that compromise the safe and successful conduct of the procedure

1.2.2. Relative

• •Pregnancy
• •Asymptomatic blood pressure >180/110
• •Uncorrected coagulopathy

1.3. Antithrombotics and bleeding disorders

• •The bleeding risk is classified as low for facet injections. The general consensus is that anticoagulant and antiplatelet therapy do not need to be discontinued before these procedures.

1.4. Procedural sedation

• •Sedation is not intrinsically necessary for facet joint injections, but if employed in unique circumstances (e.g., movement disorder, cases of extreme anxiety, previous vasovagal response), the patient should remain able to communicate pain or other adverse sensations or events. Deep sedation and general anesthesia are contraindicated.
• •The use of sedation may alter diagnostic conclusions.
• •The use of analgesic (e.g., opioids) and anxiolytic medications will affect perceived pain and negatively alter diagnostic results.
• •The decision to use sedation for an appropriate indication should be made on a case-by-case basis. Patients should be advised during informed consent that procedural sedation is not necessary but elective.
• •If the physician performing the procedure decides that sedation is indicated, a separate healthcare provider must administer the medications and monitor the patient.
• •Resuscitation drugs, appropriate monitoring equipment, and oxygen must be available if sedation is utilized.

1.5. Safe, aseptic practices

• •
  Strict aseptic technique should always be applied to the facility, patient, physician, assisting personnel, injectate/syringe, and other procedural materials. Examples include but are not limited to:

  • o
    Skin overlying the target region should be prepared for an aseptic procedure, preferably using chlorhexidine in alcohol. The area should then be draped to create a sterile field.
  • o
    A face mask and sterile gloves must be worn during the procedure.
  • o
    Sterile single-use syringes and needles are required, and single-dose vials should be utilized when available.
  • o
    Acquisition, storage, and utilization of medications should adhere to relevant regulatory guidelines.

1.6. Imaging

• •The use of image guidance is critical for appropriate needle placement. Image guidance reduces the risk of complications, allowing the physician to avoid vulnerable vascular or neural structures, such as the spinal cord in the case of cervical facet joint injections, as well as the pleural cavity in the case of thoracic facet joint injections during needle insertion and before any agent is injected. Live imaging during contrast medium injection ensures that the injected agent is delivered to the target and nowhere else.
• •Before performing cervical facet joint injections, the physician must understand the concepts of true lateral/AP imaging for the lateral approach and true lateral/AP pillar imaging for the posterior approach.
• •The safety of fluoroscopically-guided facet joint injections has been described in the medical literature, while the same rigor of investigation has not been applied to alternative image-guidance modalities. Thus, fluoroscopy is currently the recommended image guidance modality for facet joint injections.
• •The fluoroscopic technique should follow the ALARA (As Low As Reasonably Achievable) principles to minimize X-ray exposure for the patient and the healthcare team.
• •Before injecting any agent, two views should be obtained – true AP, oblique, and/or true lateral – to show correct needle placement and to exclude penetration into the spinal canal or other vulnerable structures.
• •Contrast medium should be used to demonstrate an arthrogram and ensure the intra-articular flow of a subsequent injectate.
• •Non-ionic iodinated contrast media are recommended over gadolinium-based contrast media (GBCM).
• •GBCM should be used cautiously in interventional pain procedures and only when necessary. The clinical benefit of the interventional pain treatment should be weighed against the risk of catastrophic outcomes with intrathecal administration of even small amounts of GBCM, including acute neurotoxicity (confusion, acute agitation, reduced level of consciousness, visual and auditory hallucinations, seizures, severe spasticity), tachycardia, elevated blood pressure, vomiting, and respiratory failure. GBCM is not recommended for use in procedures where intrathecal access is possible; however, the possibility of intrathecal injection with properly performed facet joint injections is remote.
• •In procedures in which intrathecal access is not possible, GBCM can be utilized. However, GBCM has a lower relative radiodensity compared to iodinated contrast medium, producing a contrast flow pattern that is less apparent on fluoroscopy. Regardless, the lowest necessary volume of GBCM should be utilized.
• •Obtain images documenting the final needle position and satisfactory contrast medium spread.

1.7. Injections

• •Pre-procedure review of advanced imaging is recommended.
• •The safest choice of approach or technique to use should ultimately be made with a thorough understanding of the anatomy and orientation of the joints, balancing the potential risks and benefits of each technique for each patient.
• •Due to the transverse orientation of cervical facet joints in the coronal plane, the risk of inserting a procedure needle into the central neural axis and spinal cord using the lateral approach is significant. For this approach, frequent true AP depth imaging should be obtained during needle advancement, and a final true AP image should be obtained before injecting contrast medium and injectate to avoid catastrophic spinal cord injury.
• •A lateral approach for C7-T1 facet joint access is not recommended due to the risk of pneumothorax.
• •In the cervical spine, there is a risk of trespass of or inadvertent injection into arterial structures, which carries the risk of ischemic or embolic complications.
• •The use of the non-particulate steroid dexamethasone is recommended, especially at upper cervical levels. If a local anesthetic is mixed with dexamethasone, ropivacaine should be avoided because of potential injectate precipitation.
• •The final needle position within the intra-articular facet joint should be confirmed by injecting a small amount of contrast medium.
• •Physicians must be mindful of the small volume capacity of the facet joint (particularly in the cervical joints). Injectate volume should not exceed 1 ml.
• •If inadvertent extraarticular contrast medium injection obscures imaging of the target joint, termination of the procedure should be considered.

1.8. Post-procedure monitoring/follow-up

• •Patients should be monitored for an appropriate time following the injection, depending upon the nature of the intervention and the agents utilized.
• •
  Provide detailed oral and written discharge instructions to patients that outline the following:

  • o
    restrictions and recommendations for the immediate post-injection period
  • o
    potential common side effects that may occur immediately post-injection and in the days following the procedure (e.g., pain at the injection site, increased blood glucose level if steroid is administered)
  • o
    symptoms that merit immediate medical attention
  • o
    timing for resumption of usual medications and anticoagulants if discontinued for the procedure
  • o
    instructions for diabetic patients to monitor blood glucose levels for 48 h or until baseline levels have been achieved
• •Ensure patients have a follow-up plan.

Sources

• •Benzon HT, Maus TP, Kang HR, Provenzano DA, Bhatia A, Diehn F et al. The use of contrast agents in interventional pain procedures: A multispecialty and multisociety practice advisory on nephrogenic systemic fibrosis, gadolinium deposition in the brain, encephalopathy after unintentional intrathecal gadolinium injection, and hypersensitivity reactions. Anesth Analg 2021; 133(2):535–552.
• •Bogduk N (ed). Practice Guidelines for Spinal Diagnostic and Treatment Procedures, 2 nd Ed. International Spine Intervention Society, San Francisco, 2013.
• •Ehsanian R, Rosati RM, Kennedy DJ, Schneider BJ. Antiplatelet and anticoagulant risk for select spine interventions: a retrospective cohort. Pain Med 2020; 21(5):910–917. doi:10.1093/pm/pnaa009
• •Endres S, Shufelt A, Bogduk N. The risks of continuing or discontinuing anticoagulants for patients undergoing common interventional pain procedures. Pain Med 2017; 18(3):403–409.
• •Endres S, Hefti K, Schlimgen E, Bogduk N. Update of a study of not ceasing anticoagulants for patients undergoing injection procedures for spinal pain. Pain Med 2020; 21(5):918–921. doi:10.1093/pm/pnz354
• •Fraiser R, Zeng PZ, Schneider BJ et al. A multi-institutional randomized double-blind placebo-controlled prospective study of intraarticular lumbar zygapophysial joint corticosteroid injections as a treatment for chronic low back pain in a selected population. PM&R 2017; 9(9)S1:S287.
• •Goodman BS, House LM, Vallabhaneni S, Mallempati S, Willey MR, Smith MT. Anticoagulant and antiplatelet management for spinal procedures: a prospective, descriptive study and interpretation of guidelines. Pain Med 2017; 18:1218–24.
• •Maus TP, Cohen I, McCormick ZL, Schneider BJ, Smith CC, Stojanovic MP, Waring PH (Eds) (2024). Technical Manual and Atlas of Interventional Pain and Spine Procedures. International Pain and Spine Intervention Society.
• •Miller DC, Patel J, Smith CC, Spine Intervention Society Patient Safety Committee. Factfinders for patient safety: radiation safety for interventional spine procedures. Pain Med 2018; 19:629–30.
• •Narouze S, Benzon HT, Provenzano D, Buvanendran A, De Andres J, Deer T, Rauck R, Huntoon MA. Interventional spine and pain procedures in patients on antiplatelet and anticoagulant medications (second edition): guidelines from the American Society of Regional Anesthesia and Pain Medicine, the European Society of Regional Anaesthesia and Pain Therapy, the American Academy of Pain Medicine, the International Neuromodulation Society, the North American Neuromodulation Society, and the World Institute of Pain. Reg Anesth Pain Med 2018; 43:225–262.
• •Popescu A, Patel J, McCormick ZL et al. FactFinders for patient safety: Are gadolinium-based contrast media safe alternatives to iodinated contrast agents for the safe performance of spinal injection procedures? Pain Med 2018; 19(10):2089–2090. doi:10.1093/pm/pny090.
• •Smith C, King W, O'Brien D Jr, Laseter J; Spine Intervention Society's Patient Safety Committee. Masks, gowns, and caps for interventional spine pain procedures. Pain Med 2018; 19(6):1293–1294. doi:10.1093/pm/pny016
• •Smith CC, Schneider B, McCormick ZL, Gill J, Loomba V, Engel AJ, Duszynski B, King W; Standards Division of the Spine Intervention Society. Risks and benefits of ceasing or continuing anticoagulant medication for image-guided procedures for spine pain: a systematic review. Pain Med 2018; 19:438–448.

2. Lateral atlantoaxial joint access/injection

Nathaniel M. Schuster, MD; Yakov Vorobeychik, MD, PhD; and Adrian Popescu, MD.

2.1. Personnel

• •Only physicians trained in the technique and interpretation of lateral atlantoaxial joint (LAAJ) access and injection should perform this procedure.
• •Appropriately trained personnel are needed to operate the fluoroscopy unit or assist the physician.

2.2. Contraindications

2.2.1. Absolute

• •An active systemic infection or a localized infection within the procedural field
• •Uncooperative patient or inability to obtain informed consent
• •Allergy to medication(s) or iodinated contrast media that cannot safely be omitted or mitigated by pre-treatment
• •Hypertensive emergency/urgency
• •Anatomical derangements that compromise the safe and successful conduct of the procedure

2.2.2. Relative

• •Pregnancy
• •Asymptomatic blood pressure >180/110
• •Uncorrected coagulopathy
• •Concurrent treatment with anticoagulants constitutes a relative contraindication for atlantoaxial joint injections due to regional anatomy and variability in the anatomy of the vascular structures.

2.3. Antithrombotics and bleeding disorders

• •The decision to continue or how to temporarily discontinue anticoagulation/antiplatelet (AC/AP) therapy must take into account potential complications in each scenario.
• •There is a quantifiable risk of life-threatening thrombotic events associated with discontinuation of therapeutic AC/AP agents for spine interventions.
• •The decision to temporarily discontinue AC/AP therapy and whether to employ a bridging strategy should include the patient and the physician prescribing the AC/AP therapy.
• •The bleeding risk is classified as high for LAAJ injections.

2.4. Procedural sedation

• •Sedation is not intrinsically necessary for LAAJ injections, but if employed in unique circumstances (e.g., movement disorder, cases of extreme anxiety, previous vasovagal response), the patient should remain able to communicate pain or other adverse sensations or events. Deep sedation and general anesthesia are contraindicated.
• •The use of sedation may alter diagnostic conclusions.
• •The use of analgesic (e.g., opioids) and anxiolytic medications will affect perceived pain and negatively alter diagnostic results.
• •The decision to use sedation for an appropriate indication should be made on a case-by-case basis. Patients should be advised during informed consent that procedural sedation is not necessary but elective.
• •If the physician performing the procedure decides that sedation is indicated, a separate healthcare provider must administer the medications and monitor the patient.
• •Resuscitation drugs, appropriate monitoring equipment, and oxygen must be available if sedation is utilized.

2.5. Safe, aseptic practices

• •
  Strict aseptic technique should always be applied to the facility, patient, physician, assisting personnel, injectate/syringe, and other procedural materials. Examples include but are not limited to:

  • o
    Skin and hair overlying the target region should be prepared for an aseptic procedure, preferably using chlorhexidine in alcohol. The area should then be draped to create a sterile field.
  • o
    A face mask and sterile gloves must be worn during the procedure.
  • o
    Sterile single-use syringes and needles are required, and single-dose vials should be utilized when available.
  • o
    Acquisition, storage, and utilization of medications should adhere to relevant regulatory guidelines.

2.6. Imaging

• •Review of advanced imaging (e.g., MRI, CT, or CT angiogram) of the target area is required, and the physician must identify any anatomical barriers, anatomical variants, and associated risks. The physician should confirm that the vertebral artery remains lateral to the LAAJ and does not course posterior to the joint where the needle will traverse. Ultrasound may be considered before the injection to confirm that the vertebral artery does not lie posterior to the joint.
• •Use of image guidance is critical for appropriate needle placement and monitoring contrast medium flow patterns. Image guidance informs needle trajectory and helps the physician avoid vulnerable vascular or neural structures during needle insertion and agent injection.
• •Fluoroscopic guidance has been used in the primary literature validating the safety and efficacy of LAAJ injections; if alternative imaging guidance is to be used (e.g., CT), it must be utilized to exclude vascular or intrathecal uptake and document flow reaching the target joint. Given the lack of studies on ultrasound utilization for this high-risk procedure, the exclusive use of ultrasound guidance is inappropriate for LAAJ injections.
• •The fluoroscopic technique should follow the ALARA (As Low As Reasonably Achievable) principles to minimize X-ray exposure for the patient and the healthcare team.
• •
  All LAAJ injections should be performed using image guidance (preferably fluoroscopy), with appropriate true AP/lateral segmental views, utilizing live fluoroscopy and/or digital subtraction imaging (if available) for contrast medium injection under an AP view.

  • o LAAJ injections may not be performed without contrast medium.
• •Obtain images documenting the final needle position and satisfactory contrast medium spread.
• •The medial half of the LAAJ lies anterior to the thecal sac. If the needle strays medially, LAAJ injections pose a particularly high risk of dural puncture; therefore, GBCM is not advised for LAAJ injections.

2.7. Injections

• •
  Ultimately, the entry point into the joint will lie over the middle of the lateral third of the joint line, but initially, the needle should be placed on bone immediately adjacent to this entry point. The joint does not present a substantial AP depth at its lateral end and can be easily over-penetrated by the needle. Touching bone before insertion into the joint cavity guards against over-penetration of the joint. Insertion too deeply through the joint risks penetration of the internal carotid artery or the posterior oropharynx. The needle must be advanced in small increments, with frequent, intermittent true AP/lateral imaging, to check for any deviations from the intended course and for the depth of the needle.

  • o
    Insertion or misdirection too far medially risks piercing the dural sac or the nerve root sleeve of C2.
  • o
    Insertion or misdirection laterally risks encountering the vertebral artery.
  • o
    Slow advancement of the needle in small increments allows the patient to indicate if the C2 ganglion or rami are touched, whereupon the needle can be promptly withdrawn and redirected.
• •LAAJ injections should be performed by injecting contrast medium under real-time fluoroscopy and/or digital subtraction imaging, using a true AP view, before injecting any substance that may be hazardous to the patient. Before the injection of contrast medium, the needle should be aspirated. The needle tip may have lodged in a posterior meniscoid of the joint. Since this is a vascular structure, blood might be drawn from it. In that event, after confirming safe needle depth using lateral and AP views, consider slight advancement in an attempt to exit the meniscoid.
• •The volume of contrast medium should not exceed 0.3 ml, leaving enough capacity to accommodate subsequent injection of local anesthetic and/or steroid. The total volume of the injectate should not exceed 1 ml to prevent overfilling the joint.
• •Although a purely intra-articular injection precludes arterial distribution, the proximity of the needle to the vertebral artery (or its potential muscular branches) and ascending and deep cervical arteries creates risk to neural structures if the needle is misplaced. The use of the nonparticulate steroid dexamethasone is therefore recommended, especially for LAAJ injections.
• •If a local anesthetic is mixed with dexamethasone, ropivacaine should be avoided because of potential injectate precipitation.
• •Microbore extension tubing is recommended for all LAAJ injections to minimize needle tip movement once it has reached its appropriate target. The physician should be mindful that the volume of the joint is small (<1.0 ml) and should consider aspirating the contrast medium from the needle hub and microbore extension tubing and filling it with therapeutic injectate to maximize medication delivery and avoid overdistention or rupture of the joint.

2.8. Post-procedure monitoring/follow-up

• •Patients should be monitored for an appropriate time following the procedure, depending upon the nature of the intervention and the agents utilized.
• •
  Provide detailed oral and written discharge instructions to patients that outline the following:

  • o
    restrictions and recommendations for the immediate post-injection period
  • o
    potential common side effects that may occur immediately post-injection and in the days following the procedure, including pain at the injection site and increased blood glucose level)
  • o
    symptoms that merit immediate medical attention
  • o
    timing for resumption of usual medications and anticoagulants if discontinued for the procedure
  • o
    instructions for diabetic patients to monitor blood glucose levels for 48 h or until baseline levels have been achieved
• •Ensure patients have a follow-up plan.

Sources

• •Benzon HT, Maus TP, Kang HR, Provenzano DA, Bhatia A, Diehn F et al. The use of contrast agents in interventional pain procedures: A multispecialty and multisociety practice advisory on nephrogenic systemic fibrosis, gadolinium deposition in the brain, encephalopathy after unintentional intrathecal gadolinium injection, and hypersensitivity reactions. Anesth Analg 2021; 133(2):535–552.
• •Bogduk N (ed). Practice Guidelines for Spinal Diagnostic and Treatment Procedures, 2nd edn. International Spine Intervention Society, San Francisco, 2013.
• •Chevrot A, Cermakova E, Vallée C, Chancelier MD, Chemla N, Rousselin B, Langer-Cherbit A. C1-2 arthrography. Skeletal Radiol 1995; 24:425–9.
• •Dreyfuss P, Michaelsen M, Fletcher D. Atlanto-occipital and lateral atlanto-axial joint pain patterns. Spine 1994; 19:1125–31.
• •Edlow BL, Wainger BJ, Frosch MP, Copen WA, Rathmell JP, Rost NS. Posterior circulation stroke after C1-C2 intraarticular facet steroid injection: evidence for diffuse microvascular injury. Anesthesiology 2010; 112:1532–5.
• •Lau SW, Sun LK, Lai R, Luk MS, Ng YS, Wong NM, Lau PY. Study of the anatomical variations of vertebral artery in C2 vertebra with magnetic resonance imaging and its application in the C1-C2 transarticular screw fixation. Spine 2010; 11:1136–43.
• •Madawi AA, Casey AT, Solanki GA et al. Radiological and anatomical evaluation of the atlantoaxial transarticular screw fixation technique: Case report and review of the literature. J Neurosurg 1997; 86:961–8.
• •Maus TP, Cohen I, McCormick ZL, Schneider BJ, Smith CC, Stojanovic MP, Waring PH (Eds) (2024). Technical Manual and Atlas of Interventional Pain and Spine Procedures. International Pain and Spine Intervention Society.
• •Mellström A, Grepe A, Levander B. Atlantoaxial arthrography. A postmortem study. Neuroradiology 1980; 20:135–44.
• •Okada K. [Studies on the cervical facet joints using arthrography of the cervical facet joint (author's transl)]. Nihon Seikeigeka Gakkai Zasshi 1981; 55:563–80. Japanese.
• •Radcliff KE, Ben-Galim P, Dreiangel N, Martin SB, Reitman CA, Lin JN, Hipp JA. Comprehensive computed tomography assessment of the upper cervical anatomy: what is normal? Spine J 2010; 10:219–22.

3. Medial branch blocks

John MacVicar, MB ChB; Zachary L. McCormick, MD; Lisa Doan, MD; Johan Hambraeus, MD, PhD; Yakov Vorobeychik, MD, PhD.

3.1. Personnel

• •Only physicians trained in the technique and interpretation of medial branch blocks (MBBs) should perform this procedure.
• •Appropriately trained personnel are needed to operate the fluoroscopy unit or assist the physician.

3.2. Contraindications

3.2.1. Absolute

• •An active systemic infection or a localized infection within the procedural field
• •Uncooperative patient or inability to obtain informed consent
• •Inability to communicate pain level
• •Allergy to a local anesthetic used for the block that cannot safely be omitted or mitigated by pre-treatment
• •Hypertensive emergency/urgency
• •Anatomical derangements that compromise the safe and successful conduct of the procedure

3.2.2. Relative

• •Pregnancy
• •Asymptomatic blood pressure >180/110
• •Uncorrected coagulopathy

3.3. Antithrombotics and bleeding disorders

• •The decision to continue or how to temporarily discontinue anticoagulation/antiplatelet (AC/AP) therapy must take into account potential complications in each scenario.
• •There is a quantifiable risk of life-threatening thrombotic events associated with discontinuation of therapeutic AC/AP agents for spine interventions.
• •The decision to temporarily discontinue AC/AP therapy and whether to employ a bridging strategy should include the patient and the physician prescribing the AC/AP therapy.
• •The bleeding risk is classified as low for MBBs. The general consensus is that AC/AP therapy does not need to be discontinued before LMBBs.

3.4. Procedural sedation

• •Sedation is not intrinsically necessary for MBBs, but if employed in unique circumstances (e.g., movement disorder, cases of extreme anxiety, previous vasovagal response), the patient should remain able to communicate pain or other adverse sensations or events. Deep sedation and general anesthesia are contraindicated.
• •The use of sedation may alter diagnostic conclusions.
• •The use of analgesic (e.g., opioids) and anxiolytic medications will affect perceived pain and negatively alter diagnostic results.
• •The decision to use sedation for an appropriate indication should be made on a case-by-case basis. Patients should be advised during informed consent that procedural sedation is not necessary but elective.
• •If the physician performing the procedure decides that sedation is indicated, a separate healthcare provider must administer the medications and monitor the patient.
• •Resuscitation drugs, appropriate monitoring equipment, and oxygen must be available if sedation is utilized.

3.5. Safe, aseptic practices

• •
  Strict aseptic technique should always be applied to the facility, patient, physician, assisting personnel, injectate/syringe, and other procedural materials. Examples include but are not limited to:

  • o
    Skin overlying the target region should be prepared for an aseptic procedure, preferably using chlorhexidine in alcohol. The area should then be draped to create a sterile field.
  • o
    A face mask and sterile gloves must be worn during the procedure.
  • o
    Sterile single-use syringes and needles are required, and single-dose vials should be utilized when available.
  • o
    Acquisition, storage, and utilization of medications should adhere to relevant regulatory guidelines.

3.6. Imaging

• •The use of image guidance is critical for appropriate needle placement. Image guidance reduces the risk of complications, allowing the physician to avoid vulnerable vascular or neural structures, such as the spinal cord in the case of cervical MBBs and the pleural cavity in the case of thoracic MBBs. Image guidance also ensures that injectate is delivered to the target.
• •The safety and validity of fluoroscopically-guided MBBs have been described in the medical literature, while the same rigor of investigation has not been applied to alternative image-guidance modalities. Thus, fluoroscopy is currently the recommended image guidance modality for MBBs.
• •The fluoroscopic technique should follow the ALARA (As Low As Reasonably Achievable) principles to minimize X-ray exposure for the patient and the healthcare team.
• •True AP and true lateral and/or oblique views should be obtained to show correct needle placement and to exclude penetration into the spinal canal or other vulnerable structures.
• •Administration of contrast medium before local anesthetic is recommended to rule out vascular uptake. If MBBs are performed without contrast medium (e.g., for a patient with a documented allergy to contrast medium), there is a risk that vascular injection would not be identified and that failure of the diagnostic block to relieve pain might represent a false negative response.
• •Gadolinium-based contrast media (GBCM) should be used cautiously in interventional pain procedures and only when necessary. The clinical benefit of the interventional pain treatment should be weighed against the risk of catastrophic outcomes with intrathecal administration of even small amounts of GBCM, including acute neurotoxicity (confusion, acute agitation, reduced level of consciousness, visual and auditory hallucinations, seizures, severe spasticity), tachycardia, elevated blood pressure, vomiting, and respiratory failure. GBCM is not recommended for use in procedures where intrathecal access is possible; however, the possibility of intrathecal injection with properly performed MBBs is exceedingly remote.
• •In procedures where intrathecal access is not possible, GBCM can be utilized. However, GBCM has a lower relative radiodensity compared to iodinated contrast medium, producing a contrast flow pattern that is less apparent on fluoroscopy. Regardless, the lowest necessary volume of GBCM should be utilized.
• •Obtain images documenting the final needle position and appropriate contrast medium spread.

3.7. Injections

• •For cervical MBBs, the ultimate choice of approach or technique should be made by the treating physician by balancing the potential risks and benefits of each technique for each patient.
• •The ultimate choice of local anesthetic agent (i.e., long-acting compound, short-acting compound, placebo agent) should be made by the treating physician.

3.8. Post-procedure monitoring/follow-up

• •Patients should be monitored for an appropriate time following the procedure, depending upon the nature of the intervention and the agents utilized.
• •
  Provide detailed oral and written discharge instructions to patients that outline the following:

  • o
    restrictions and recommendations for the immediate post-procedure period
  • o
    potential common side effects that may occur immediately post-injection and in the days following the procedure
  • o
    symptoms that merit immediate medical attention
  • o
    timing for resumption of usual medications and anticoagulants if discontinued for the procedure
• •Ensure patients have a follow-up plan.

Sources

• •Benzon HT, Maus TP, Kang HR, Provenzano DA, Bhatia A, Diehn F et al. The use of contrast agents in interventional pain procedures: A multispecialty and multisociety practice advisory on nephrogenic systemic fibrosis, gadolinium deposition in the brain, encephalopathy after unintentional intrathecal gadolinium injection, and hypersensitivity reactions. Anesth Analg 2021; 133(2):535–552.
• •Bogduk N (ed). Practice Guidelines for Spinal Diagnostic and Treatment Procedures, 2nd edn. International Spine Intervention Society, San Francisco, 2013.
• •Endres S, Shufelt A, Bogduk N. The risks of continuing or discontinuing anticoagulants for patients undergoing common interventional pain procedures. Pain Med 2017; 18(3):403–409.
• •Goodman BS, House LM, Vallabhaneni S, Mallempati S, Willey MR, Smith MT. Anticoagulant and antiplatelet management for spinal procedures: a prospective, descriptive study and interpretation of guidelines. Pain Med 2017; 18:1218–24.
• •Kennedy DJ, Mattie R, Scott Hamilton A, Conrad B, Smuck M. Detection of intravascular injection during lumbar medial branch blocks: a comparison of aspiration, live fluoroscopy, and digital subtraction technology. Pain Med 2016; 17:1031–6.
• •Maus TP, Cohen I, McCormick ZL, Schneider BJ, Smith CC, Stojanovic MP, Waring PH (Eds) (2024). Technical Manual and Atlas of Interventional Pain and Spine Procedures. International Pain and Spine Intervention Society.
• •Narouze S, Benzon HT, Provenzano DA, Buvanendran A, De Andres J, Deer TR et al. Interventional spine and pain procedures in patients on antiplatelet and anticoagulant medications: guidelines from the American Society of Regional Anesthesia and Pain Medicine, the European Society of Regional Anaesthesia and Pain Therapy, the American Academy of Pain Medicine, the International Neuromodulation Society, the North American Neuromodulation Society, and the World Institute of Pain. Reg Anesth Pain Med 2015; 40:182–212.
• •Smith CC, Schneider B, McCormick ZL, Gill J, Loomba V, Engel AJ, Duszynski B, King W; Standards Division of the Spine Intervention Society. Risks and benefits of ceasing or continuing anticoagulant medication for image-guided procedures for spine pain: a systematic review. Pain Med 2018; 19(3):438–448.

4. Medial branch radiofrequency neurotomy

John MacVicar, MB ChB; Patrick H. Waring, MD; Zirong Zhao, MD, PhD; Brian Boies, MD; Yakov Vorobeychik, MD, PhD.

As an alternative to traditional monopolar electrodes, some physicians use bipolar electrodes, internally cooled RF probes, or multi-tined electrodes, which change or expand the morphology of the thermal lesion. These alternative modalities convey different safety considerations from the conventional MBRFN technique. This document considers the safety practices regarding the latter technique, which uses a single, large-gauge RF cannula.

4.1. Personnel

• •Only physicians trained in MBRFN should perform this procedure.
• •Appropriately trained personnel are needed to operate the fluoroscopy unit or assist the physician.

4.2. Contraindications

4.2.1. Absolute

• •An active systemic infection or a localized infection within the procedural field
• •Uncooperative patient or inability to obtain informed consent
• •Allergy to medication(s) that cannot safely be omitted or mitigated by pre-treatment
• •Hypotensive emergency/urgency
• •Uncontrolled blood pressure
• •Pregnancy
• •Anatomical derangements that compromise the safe and successful conduct of the procedure

4.2.2. Relative

• •Concurrent treatment with anticoagulants/antiplatelets (AC/AP) constitutes a potential relative contraindication for cervical MBRFN.
• •Asymptomatic blood pressure >180/110
• •Uncorrected coagulopathy
• •Spinal hardware is not a contraindication to MBRFN, but its presence may complicate needle placement. In addition, direct contact of the lesioning cannula with spinal hardware should be avoided to reduce the risk of heat transfer to vulnerable structures. Tissue temperature and impedance should be continuously monitored.
• •
  Caution is advised in patients who have cardiac pacemakers and defibrillators. If a decision is made to proceed with RFN in these patients, physicians should educate the patient on the potential hazards and risks of RFN in the setting of a pacemaker or defibrillator and consider the following recommendations:

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    Ensure the patient is followed by a cardiologist/electrophysiologist and obtain prior approval from the provider, which should be documented in the patient's medical record.
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    If recommended by a cardiologist or electrophysiologist:

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      Have on-site support for interrogation of the cardiac device during the procedure if reprogramming is required.
    • •
      Place a magnet over the device during the procedure to prevent triggering the device by radiofrequency energy.
    • •
      Remove the magnet or use an external defibrillator or pacing electrodes in case of cardiac arrhythmias during the RFN procedure.
    • •
      Discussion with the patient's cardiologist is recommended to ensure that safety is optimized, as technology associated with cardiac devices changes rapidly.
• •Other implantable devices, such as spinal cord and deep brain stimulators, should be turned off during the procedure. A neurologic exam should be performed before and after the procedure, and the stimulator should be restarted after the procedure to ensure proper functioning. The grounding pad should be placed so that the electrical current's path is as far as possible from the device. The procedure should be abandoned if the risk of stimulator electrode-heating during the neurotomy cannot be eliminated.

4.3. Antithrombotics and bleeding disorders

• •The decision to continue or how to temporarily discontinue AC/AP therapy must take into account potential complications in each scenario.
• •There is a quantifiable risk of life-threatening thrombotic events associated with discontinuation of therapeutic AC/AP agents for spine interventions.
• •The decision to temporarily discontinue AC/AP therapy and whether to employ a bridging strategy should include the patient and the physician prescribing the AC/AP therapy.
• •The bleeding risk is classified as low for lumbar MBRFN procedures, for which the general consensus is that AC/AP therapy does not need to be discontinued.
• •The bleeding risk is classified as low-intermediate for cervical and thoracic MBRFN.

4.4. Procedural sedation

• •Sedation is not intrinsically necessary for MBRFN, but if employed in unique circumstances (e.g., movement disorder, cases of extreme anxiety, previous vasovagal response), the patient should remain able to communicate pain or other adverse sensations or events. Deep sedation and general anesthesia are contraindicated.
• •The decision to use sedation for an appropriate indication should be made on a case-by-case basis. Patients should be advised during informed consent that procedural sedation is not necessary but elective.
• •If the physician performing the procedure decides that sedation is indicated, a separate healthcare provider must administer the medications and monitor the patient.
• •Resuscitation drugs, appropriate monitoring equipment, and oxygen must be available if sedation is utilized.

4.5. Safe, aseptic practices

• •
  Strict aseptic techniques should always be applied to the facility, patient, physician, assisting personnel, injectate/syringe, and other procedural materials. Examples include, but are not limited to:

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    Skin overlying the target region should be prepared for an aseptic procedure, preferably using chlorhexidine in alcohol. The area should then be draped to create a sterile field.
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    A face mask and sterile gloves must be worn during the procedure.
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    Sterile single-use syringes and needles are required, and single-dose vials should be utilized when available.
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    Acquisition, storage, and utilization of medications should adhere to relevant regulatory guidelines.
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    Single-use or reusable probes are appropriate; reusable probes are appropriate if proper sterilization techniques are employed between patients and procedures.

4.6. Imaging

• •The use of image guidance is critical for appropriate cannula placement.
• •Fluoroscopic guidance has been used in the primary literature validating the safety and efficacy of MBRFN. There is no current, robust evidence validating ultrasound, MRI, or other imaging guidance, and their routine use is not recommended unless such evidence becomes available. CT scan is an extension of fluoroscopic guidance with increased cost and is not widely available.
• •The fluoroscopic technique should follow the ALARA (As Low As Reasonably Achievable) principles to minimize X-ray exposure for the patient and the healthcare team.
• •Obtain image(s) showing the final cannula/lesioning device position in at least two views (AP and lateral).
• •RF lesioning should not be performed if the physician is uncertain about the cannula's position in relation to the targeted medial branch and other vulnerable neural structures.

4.7. Neurotomy

• •A dispersive pad should be completely adhered to the skin with the long axis of the pad facing the active RF electrode to minimize the risk of a dispersive pad skin burn. The pad should be placed to maximize its distance from the RF electrode.
• •Sensory and motor testing is not required for safety or efficacy if appropriate care is taken in electrode placement.
• •Impedance and temperature at the electrode tip should be monitored. Lesioning above 90 °C is not recommended due to the risk of cavitation resulting in inconsistent lesion sizes and shapes. If at any time during temperature escalation or coagulation, an adverse sensation indicative of ventral ramus involvement is reported by the patient, the generator should be turned off and the causes evaluated and corrected. If adverse symptoms persist, consideration should be given to aborting the procedure.

4.7.1. Cervical medial branch radiofrequency neurotomy (CMBRFN)

• •At all times, the electrode must remain behind the anterior margin of the articular pillar on the true lateral segmental view and overlap just medial or parallel to the lateral silhouette of the articular pillar on the AP pillar view during an oblique pass or sagittal pass, respectively. During lesioning, the cannula's active tip should maintain contact with the articular pillar on true AP/lateral views, and the tip of the cannula should remain safely posterior to the foramen in the foraminal oblique view.
• •Bilateral CMBRFNs should be avoided. Each side should be performed at separate visits because of the increased risk of compromise of the cervical musculature and permanent head drop. In addition, bilateral third occipital nerve RFN should be avoided, with each side performed on separate visits because of the risk of disabling ataxia.

4.7.2. Lumbar medial branch radiofrequency neurotomy

• •The electrode should avoid the ventral quarter of the neck of the superior articular process (SAP) to avoid unnecessarily lesioning the lateral or intermediate branches. Further advancement beyond the anterior aspect of the SAP can directly damage the ventral ramus or spinal nerve.

4.8. Post-procedure monitoring/follow-up

• •Patients should be monitored for an appropriate time following the procedure, depending upon the nature of the intervention and the agents utilized.
• •
  Provide detailed oral and written discharge instructions to patients that outline the following:

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    restrictions and recommendations for the immediate post-procedure period
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    potential common side effects that may occur immediately post-procedure and in the days following the procedure
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    symptoms that merit immediate medical attention
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    timing for resumption of usual medications and anticoagulants if discontinued for the procedure.
• •Ensure patients have a follow-up plan.

Sources

• •Bogduk N (ed). Practice Guidelines for Spinal Diagnostic and Treatment Procedures, 2nd edn. International Spine Intervention Society, San Francisco, 2013.
• •Barbieri M, Bellini M. Radiofrequency neurotomy for the treatment of chronic pain: interference with implantable medical devices. Anaesthesiology Intensive Therapy 2014; 46:162.
• •Hurley RW, Adams MCB, Barad M et al. Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group. Reg Anesth Pain Med. 2022; 47(1):3–59. doi:10.1136/rapm-2021-103031
• •Lamer TJ, Smith J, Hoelzer BC, Mauck WD, Qu W, Gazelka HM. Safety of lumbar spine radiofrequency procedures in patients who have posterior spinal hardware. Pain Medicine 2016; 17:1634–7.
• •Maus TP, Cohen I, McCormick ZL, Schneider BJ, Smith CC, Stojanovic MP, Waring PH (Eds) (2024). Technical Manual and Atlas of Interventional Pain and Spine Procedures. International Pain and Spine Intervention Society.
• •McCormick ZL, Smith CC, Engel AJ. Factfinders for patient safety: preventing external skin burns during thermal radiofrequency neurotomy. Pain Med 2019; 20(4):852–853.
• •Smith C, DeFrancesch F, Patel J; Spine Intervention Society's Patient Safety Committee. Radiofrequency neurotomy for facet joint pain in patients with permanent pacemakers and defibrillators. Pain Med 2019; 20(2):411–412. doi:10.1093/pm/pny213

Disclaimer

While these Safety Practices are intended to identify elements critical to the safe performance of interventional spine procedures, they are not intended to be inclusive of all proper methods relevant to the safe performance of spine procedures or exclusive of other methods of care reasonably utilized to obtain the same results. Nothing contained in these documents is intended to be used as a substitute for the care and knowledge of the individual clinician. They are guidelines based on evidence-informed expert consensus. IPSIS makes no representation and assumes no responsibility for the accuracy of the information contained or available through this website, and such information is subject to change without notice. Given the individual patient's clinical circumstances and preferences, the clinician's independent medical judgment should always determine patient care and treatment. Practitioners are advised to consider management options in the context of their training and background and institutional capabilities when selecting recommended treatment options. IPSIS is not responsible, nor does it assume any legal liability or responsibility for the accuracy, completeness, clinical efficacy, or value of any such information or apparatus, product, or process described or referenced.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.