Is cervical artificial disc arthroplasty (CPT code 22856) and microsurgery add-on (CPT code 69990) medically necessary for a patient with a small, asymptomatic carotid aneurysm (I72.0)?

Medical Necessity Determination: Cervical Disc Arthroplasty and Microsurgery for Carotid Aneurysm

Direct Answer

The requested procedures (CPT 22856 - cervical artificial disc arthroplasty and CPT 69990 - microsurgery add-on) are NOT medically necessary for diagnosis I72.0 (carotid artery aneurysm) as there is a complete mismatch between the diagnosis and the procedures being requested.

Critical Analysis of the Case

Fundamental Procedural-Diagnostic Mismatch

• CPT 22856 is a cervical spine procedure for total disc arthroplasty involving discectomy and end plate preparation of the cervical intervertebral disc, which has absolutely no relationship to treating a carotid artery aneurysm 1

• CPT 69990 (operating microscope add-on) is considered an integral part of spinal surgery and is not separately reimbursable according to Aetna policy, and more importantly, is irrelevant to carotid aneurysm treatment 1

• The diagnosis I72.0 (aneurysm of carotid artery) requires vascular interventions, not spinal procedures 2, 3, 4

Appropriate Management for the Actual Diagnosis

The clinical documentation describes a 64-year-old female with a small (4.8 x 3.6 mm) unruptured right cavernous carotid aneurysm that was incidentally discovered. Based on established guidelines:

Conservative Management is Indicated

• Small aneurysms <5mm should be managed conservatively in virtually all cases according to neurosurgical guidelines 1

• The annual rupture risk for a cavernous carotid aneurysm of this size is approximately 0.1%, making aggressive intervention unjustified 5

• Asymptomatic patients with small aneurysms require observation, not surgical intervention 1

Appropriate Interventions if Treatment Were Needed

If this aneurysm required treatment (which it does not at this size), the appropriate procedures would be:

• Endovascular coiling or flow diverter placement (which was actually performed per the operative report showing Elite flow diverter 4.25 x 15mm deployment) 1

• Microsurgical clipping for accessible anterior circulation aneurysms in young, low-risk patients 1

• CPT codes 61624 (endovascular surgery), 75894 (transcatheter therapy imaging), and 36217 (selective catheter placement) as documented in the related case, NOT cervical disc procedures 1

Inpatient Stay Assessment

• The diagnostic angiogram for a small, asymptomatic carotid aneurysm does not meet MCG criteria for inpatient admission 1

• MCG Neurology criteria require cerebral aneurysm with need for IV antihypertensive agents, sedation for suspected leak, external ventricular drainage, or emergent surgical evaluation - none of which apply to this stable, incidental finding 1

• Outpatient diagnostic angiography is appropriate for evaluating small, asymptomatic aneurysms 5

Recommendation Summary

Non-certification is appropriate for:

1. CPT 22856 (cervical disc arthroplasty) - completely unrelated to carotid aneurysm diagnosis 1

2. CPT 69990 (microsurgery add-on) - not separately reimbursable for spinal procedures and irrelevant to vascular pathology 1

3. Inpatient admission - not medically necessary for diagnostic evaluation of small, asymptomatic carotid aneurysm 1, 5

What Should Have Been Done

• Optimal medical therapy with risk factor modification (blood pressure control, antiplatelet therapy, statin therapy) 5

• Surveillance imaging to monitor for aneurysm growth 5

• Outpatient diagnostic angiography if detailed characterization was needed 1, 5

• If intervention were truly indicated, endovascular treatment with flow diversion (which appears to have actually been performed based on the operative note) using appropriate CPT codes 1, 3