Thalamic anastomosis as a potential marker of perioperative ischemic risk in moyamoya disease

Revascularization surgery is a well-established intervention for both ischemic and hemorrhagic moyamoya disease (MMD). Perioperative ischemic stroke occurs in 5-18% of surgeries, however, evidence-based information for its prevention and related factors remain insufficiently established. The development of collateralization pathways in MMD may play a significant role in optimizing cerebral perfusion as much as possible, therefore, during cerebral revascularization surgery, the tolerance to ischemia may vary depending on the developmental pattern of the preoperative collateral circulation. The aim of this study is to investigate whether differences in preoperative angioarchitecture is associated with the risk of ischemic complications during the perioperative period of revascularization surgery for MMD. This study included 53 hemispheres from 37 consecutive patients with MMD who underwent surgical revascularization between January 2014 and September 2024. The primary outcome was clinically overt perioperative ischemic stroke, defined as an acute-onset focal neurologic deficit accompanied by ipsilateral high-intensity signals on diffusion-weighted magnetic resonance imaging within seven days post-surgery. Among 37 patients (53 hemispheres) with MMD, perioperative ischemic complications occurred in 4 hemispheres (7.55%). The patients with ischemic complications demonstrated a significantly higher prevalence of preoperative angioarchitecture characterized by the presence of thalamic anastomosis compared to those without ischemic complications (p < 0.05). The presence of well-developed thalamic anastomosis in MMD may be associated with perioperative ischemic complications; however, this potential association requires validation in larger-scale studies.