Fractional Flow Reserve–Guided Submaximal Balloon Angioplasty for Symptomatic Intracranial Stenosis

BACKGROUND AND IMPORTANCE: Symptomatic intracranial atherosclerotic disease due to hemodynamic failure remains challenging to manage, particularly in patients who fail aggressive medical therapy. While submaximal angioplasty can restore luminal caliber and improve perfusion, real-time physiologic assessment during neurointervention is limited. Fractional flow reserve (FFR), widely used in coronary interventions, offers a direct measure of pressure gradients across stenotic lesions. CLINICAL PRESENTATION: We report the application of intracranial FFR measurement in a 62-year-old woman with medically refractory, hemodynamically significant right M1 stenosis. Preprocedural computed tomography perfusion confirmed impaired cerebral blood flow. Using a pressure-sensing microwire, FFR was measured before and after submaximal balloon angioplasty, demonstrating substantial improvement in physiologic flow alongside increased luminal diameter and normalization of perfusion imaging. The patient experienced clinical recovery without complications. CONCLUSION: This case highlights the feasibility and potential value of FFR to quantify intracranial hemodynamics, guide angioplasty, and complement angiography in the treatment of symptomatic intracranial atherosclerotic disease.