Is procedure code 37215 considered medically necessary for a patient with complete occlusion of the left Internal Carotid Artery (ICA) and symptoms of stroke, including right-sided weakness and respiratory distress requiring intubation?

Medical Necessity of CPT 37215 for Complete Left ICA Occlusion in Acute Stroke

CPT code 37215 (transcatheter placement of intravascular stent, cervical carotid artery) is medically necessary and indicated for this patient with acute symptomatic left ICA occlusion presenting within the thrombectomy time window, despite the complete occlusion noted on imaging. 1

Primary Justification for Medical Necessity

The 2015 AHA/ASA guidelines explicitly support angioplasty and stenting of proximal cervical atherosclerotic stenosis or complete occlusion at the time of thrombectomy (Class IIb; Level of Evidence C), particularly when performed within 6 hours of symptom onset. 1 This patient meets all critical criteria:

• Acute symptomatic presentation with right-sided weakness and speech changes occurring at a defined time 1
• Tandem occlusion involving both cervical ICA origin and M2 branch, confirmed on CTA 1
• Emergent intervention performed within the therapeutic window 1
• Respiratory compromise requiring intubation, establishing high clinical acuity and need for aggressive intervention 1

Key Distinction: Acute vs. Chronic Occlusion

The MCG criteria's focus on "50-99% stenosis" creates confusion, but this represents an acute occlusion in the setting of acute stroke, not a chronic total occlusion. 1, 2 The critical distinctions are:

• Chronic total occlusion (contraindicated for revascularization): Established occlusion discovered incidentally or in stable patients 1, 2
• Acute occlusion (indicated for intervention): Occlusion occurring as the precipitating event for acute stroke symptoms, as in this case 1, 3

The AHA/ASA guidelines specifically included patients with complete atherosclerotic cervical carotid occlusion in major thrombectomy trials (MR CLEAN, REVASCAT, ESCAPE), with substantial proportions ranging from 18.6% to 32.2% of enrolled patients. 1 In ESCAPE, patients with cervical ICA occlusion showed significant benefit (OR 8.7; 95% CI 1.9-39.4). 1

Evidence Supporting Intervention in Tandem Occlusions

Mechanical thrombectomy combined with cervical ICA stenting demonstrates superior outcomes compared to medical therapy alone in acute tandem occlusions: 3

• Recanalization rates: 87% with stenting vs. 48% with thrombolysis alone (p=0.001) 3
• Favorable functional outcome: 68% vs. 15% (p<0.001) 3
• Mortality reduction: 18% vs. 41% (p=0.048) 3

The 2015 AHA/ASA guidelines acknowledge that 30 of 75 patients (40%) with carotid stenosis or occlusion in the MR CLEAN intervention arm were stented during thrombectomy, and 9 of 19 patients with carotid occlusion in REVASCAT received stents. 1

Addressing the Hemorrhage Risk Concern

The guidelines note that urgent stenting typically requires antiplatelet prophylaxis, which has been associated with intracranial hemorrhage. 1 However, this patient's clinical course demonstrates appropriate management:

• No intracranial hemorrhage occurred during hospitalization [@case history@]
• Small areas of acute infarction on follow-up MRI, not massive infarction [@case history@]
• Successful extubation and clinical improvement (57% improvement rate in similar cases) 4

Clinical Outcome Data Supporting Necessity

Recent surgical series of acute ICA occlusion revascularization within 72 hours demonstrate: 4

• 86% patency achievement 4
• 6% intracranial hemorrhage rate (acceptable risk) 4
• 57% clinical improvement rate (≥1 point Rankin scale improvement) 4
• 6% mortality (significantly lower than natural history) 4

Common Pitfall: Misapplying Chronic Occlusion Guidelines

The critical error in the MCG denial logic is conflating chronic total occlusion (Class III contraindication) with acute symptomatic occlusion during active stroke. 1, 2 The ACC/AHA guideline stating "carotid revascularization is not recommended for patients with chronic total occlusion" 1 explicitly applies to chronic, stable occlusions, not acute thrombotic events precipitating stroke. 2

The imaging description of "complete occlusion" represents the angiographic appearance at the time of acute presentation, not a longstanding chronic occlusion. 1 The presence of intracranial reconstitution at the distal cavernous segment confirms this is an acute process with collateral flow attempting to compensate. [@case history@]

Procedural Appropriateness

This patient required emergent intervention for: 1

• Salvage of ischemic penumbra documented on CT perfusion [@case history@]
• Prevention of stroke progression in the setting of tandem occlusion 1
• Restoration of antegrade flow to maximize functional recovery 1, 3

The technical goal of achieving TICI 2b/3 recanalization (Class I; Level of Evidence A) often requires addressing the proximal cervical lesion in tandem occlusions. 1

Final Determination

CPT 37215 is medically necessary for this acute symptomatic tandem occlusion. The procedure was performed emergently within the therapeutic window for a patient with documented ischemic penumbra, respiratory compromise requiring intubation, and complete cervical ICA occlusion with tandem M2 occlusion. 1, 3 The MCG criteria's focus on "50-99% stenosis" does not exclude acute complete occlusions in the thrombectomy setting, as evidenced by major trial inclusion criteria and guideline recommendations. 1