Subintimal recanalization for non-acute occlusion of intracranial vertebral artery in an emergency endovascular procedure: A case report

BACKGROUND: Endovascular recanalization of non-acute intracranial artery occlusion is technically difficult, particularly when the microwire enters the subintima. Although the subintimal tracking and re-entry technique has been well established in the endovascular treatment of coronary artery occlusion, there is limited experience with its use in intracranial occlusion due to anatomical variations and a lack of dedicated devices. CASE SUMMARY: A 74-year-old man was admitted to the hospital two days after experiencing acute weakness in both lower extremities, poor speech, and dizziness. After admission, imaging revealed acute ischemic stroke and non-acute occlusion of bilateral intracranial vertebral arteries (ICVAs). On the fourth day of admission, the patient's condition deteriorated and an emergency endovascular recanalization of the left ICVA was performed. During this procedure, a microwire was advanced in the subintima of the vessel wall and successfully reentered the distal true lumen. Two stents were implanted in the subintima. The patient's Modified Rankin Scale was 1 at three months postoperatively. CONCLUSION: We present a technical case of subintimal recanalization for non-acute ICVA occlusion in an emergency endovascular procedure. However, we emphasize the necessity for caution when applying the subintimal tracking approach in intracranial occlusion due to the significant dangers involved.