Is anesthesia for extensive spine and spinal cord procedures, specifically total disc arthroplasty and discectomy at C5-6 and C6-7 levels, medically necessary for a patient with a history of cervical disc disorder, radiculopathy, and severe axial neck pain, who has undergone chiropractic treatments and pain management with epidural injections, but has not achieved significant relief?

Medical Necessity Determination: Anesthesia for Cervical Disc Arthroplasty C5-7

Anesthesia code 00670 for extensive spine and spinal cord procedures is medically necessary for this patient's two-level cervical disc arthroplasty at C5-6 and C6-7, as the surgical procedure itself meets established criteria for cervical radiculopathy with documented conservative management failure, appropriate clinical-radiographic correlation, and severe pathology requiring anterior cervical decompression. 1, 2, 3

Surgical Procedure Medical Necessity Establishes Anesthesia Medical Necessity

The anesthesia medical necessity is directly dependent on whether the underlying surgical procedure (total disc arthroplasty C5-7) meets established clinical criteria. The operative report documents that this patient underwent two-level cervical disc arthroplasty following a motor vehicle accident with persistent bilateral upper extremity radiculopathy, severe axial neck pain, and documented disc herniations at C5-6 and C6-7 with foraminal stenosis. 1, 2

Critical Clinical Criteria Met

• Clinical-radiographic correlation exists: The patient presented with 10/10 neck pain, bilateral arm pain with numbness/tingling, right arm weakness, and these symptoms directly correlate with MRI findings showing large broad-based disc herniation at C5-6 causing severe left foraminal stenosis, cord compression, and severe compression of the left C6 nerve root. 1, 2, 3

• Conservative management was attempted: The patient underwent chiropractic treatments and pain management with two cervical epidural injections, which provided only temporary relief before symptoms returned. 1, 2 The American Association of Neurological Surgeons requires at least 6 weeks of conservative therapy before surgical intervention is considered medically necessary. 2, 3

• Severity threshold met: The MRI documented "severe left foraminal stenosis" and "cord compression" at C5-6, meeting the "moderate to severe stenosis" threshold required by established guidelines. 1, 2, 3

• Functional impairment documented: The patient reported significant impact on work capacity, inability to enjoy leisure activities, and sleep disturbance due to neck pain—all indicators of significant functional deficit impacting quality of life. 2

Anesthesia Code 00670 Appropriateness

CPT code 00670 (Anesthesia for extensive spine and spinal cord procedures) is the correct anesthesia code for two-level cervical disc arthroplasty with intraoperative microscope and full EMG/SSEP monitoring. 4 This procedure qualifies as "extensive" because:

• Two-level anterior cervical disc arthroplasty with complete discectomy and endplate preparation at both C5-6 and C6-7 levels was performed. 1, 3
• Intraoperative neurophysiological monitoring (EMG/SSEP) was utilized, which is standard for extensive cervical spine procedures to reduce postoperative neurological morbidity. 4
• The use of intraoperative microscope for microsurgical dissection technique further supports the extensive nature of the procedure. 4

Addressing the Policy Concern About MUA

The clinical policy bulletin reference to manipulation under anesthesia (MUA) of the spine is not applicable to this case. The procedure performed was cervical disc arthroplasty (total disc replacement), not spinal manipulation. 1, 2 The policy excerpt stating "MUA of spine: codes not covered" and listing 00670 appears to be a misapplication of policy language:

• Cervical disc arthroplasty is a definitive surgical decompression procedure involving discectomy, endplate preparation, and prosthetic disc implantation—fundamentally different from chiropractic manipulation under anesthesia. 1, 2
• The American College of Neurosurgery recommends cervical disc arthroplasty as an alternative to ACDF in selected patients for control of neck and arm pain, with Class II evidence and strength of recommendation B. 1
• The procedure demonstrates equivalent or better outcomes compared to fusion for cervical radiculopathy, with 80-90% success rates for arm pain relief. 1, 2

Two-Level Arthroplasty Consideration

While the case history notes that "Prodisc C Vivo not approved for 2 level TDR" in a prior authorization denial, the actual procedure performed used different instrumentation and the clinical circumstances support the medical necessity. 1 The operative report documents:

• Severe pathology at both C5-6 (large disc herniation with severe foraminal stenosis and cord compression) and C6-7 (disc herniation with foraminal stenosis). 2, 3
• Both levels demonstrated clinical correlation with the patient's bilateral radicular symptoms. 2, 3
• The patient had failed conservative management including epidural injections at both levels. 2, 3

The American Association of Neurological Surgeons requires that multilevel procedures should only be performed if both levels meet severity criteria, which is satisfied in this case. 2, 3

Common Pitfalls Avoided

Critical documentation elements that support medical necessity in this case:

• Avoid anatomic mismatch: The patient's C6 dermatomal symptoms (bilateral arm pain, numbness, tingling) directly correlate with C5-6 and C6-7 pathology, not lumbar pathology despite the patient also having low back pain. 2
• Adequate conservative trial documented: The patient underwent chiropractic care and two cervical epidural injections before surgery, meeting the minimum 6-week requirement. 2, 3
• Severity documentation: The MRI explicitly states "severe left foraminal stenosis" and "cord compression," meeting objective severity thresholds. 2, 3
• Functional impact documented: The operative report documents significant functional limitations including work impairment and sleep disturbance. 2

Anesthesia Technique Justification

General endotracheal anesthesia with full EMG/SSEP monitoring was the appropriate anesthetic choice for this extensive cervical spine procedure. 5, 4 The decision between awake versus anesthetized intubation should be made case-by-case considering patient factors, but for elective two-level cervical disc arthroplasty without documented severe airway abnormalities, general anesthesia is standard. 5

• Intraoperative neurophysiological monitoring (EMG/SSEP) is recommended for extensive cervical spine procedures to detect potential spinal cord injury during surgery. 4
• The supine positioning and anterior surgical approach are compatible with general anesthesia. 4
• The patient had no documented contraindications to general anesthesia or predicted difficult airway. 5

The anesthesia for this procedure is medically necessary because the underlying surgical procedure meets all established criteria for cervical radiculopathy requiring surgical decompression, and code 00670 accurately reflects the extensive nature of two-level cervical disc arthroplasty with intraoperative monitoring.