Panvascular Changes Under Intensive Medical Therapy in Intracranial Atherosclerotic Steno‐Occlusive Disease

Background While intensive medical therapy improves culprit plaque characteristics in intracranial atherosclerotic steno‐occlusive disease, its broader effects on the intracranial arterial tree, venous pathways, and meningeal lymphatic system remain unclear. We explored longitudinal panvascular changes in patients with intracranial atherosclerotic steno‐occlusive disease under intensive therapy. Methods We included patients with a first‐ever intracranial atherosclerotic steno‐occlusive disease–related stroke who received intensive medical therapy and underwent multimodal magnetic resonance imaging at baseline and 6‐month follow‐up. Quantitative assessments included plaque burden and lumen area at the culprit artery, global arterial tree morphology, internal jugular vein area, and meningeal lymphatic vessel volume. Associations between low‐density lipoprotein cholesterol reduction and vascular metrics were analyzed using adjusted generalized additive models. Results Among 24 enrolled patients, plaque burden at the site of maximal stenosis in the culprit artery decreased significantly (mean difference, −5.24% [95% CI, −9.25% to −1.23%]). Global arterial tree length (mean difference, 278.89 mm [95% CI, 26.60–531.18 mm]) and volume (mean difference, 411.38 mm 3 [95% CI, 36.9–785.87 mm 3 ]) increased, while the mean arterial diameter decreased (mean difference, −0.05 mm [95% CI, −0.08 to −0.01 mm]). Meningeal lymphatic vessel volume also expanded (mean difference, 337.42 mm 3 [95% CI, 73.08–601.75 mm 3 ]). No significant changes were observed in the cross‐sectional area of the internal jugular vein. Greater reduction in low‐density lipoprotein cholesterol was associated with more pronounced improvements among these panvascular metrics. Conclusions These findings reveal coordinated arterial and lymphatic changes beyond local plaque regression. Future studies are warranted to further explore these systemic changes and their clinical implications.