Chronic Remote Ischemic Conditioning in Small Infarctions Associated with Stent-assisted Coiling of Unruptured Intracranial Aneurysms: a Single-center Randomized Controlled Trial.

1. Disease Description Stent-assisted coiling has become an effective treatment modality for intracranial aneurysms. With continuous advancements in periprocedural antiplatelet regimens, the incidence of symptomatic thromboembolic events has significantly decreased. However, the rate of procedure-related microembolic infarctions, which are characterized by punctate hyperintense signals on DWI, remains high (10%-76.5%). The underlying causes of these microembolic infarctions remain controversial and may be associated with factors such as different stent types, sheath types, antiplatelet regimens, intraoperative adverse events (e.g., vascular dissection or spasm), patient age, and procedure duration. While most patients with microembolic infarctions exhibit no overt clinical symptoms, the presence of these infarctions reflects underlying tissue damage, posing potential risks that cannot be ignored. Furthermore, their occurrence highlights insufficient preoperative preparation or intraoperative technical issues, which may increase the likelihood of symptomatic embolism. Therefore, investigating the causes of microembolic infarctions and exploring preventive strategies is of great clinical significance.
2. Intervention Description Remote ischemic conditioning (RIC) involves inducing temporary ischemia in distal vessels to protect target vessels from ischemic and reperfusion injuries. RIC can be performed before, during, or after ischemic events and is widely used in the context of coronary artery ischemia. Some studies have shown that RIC can mitigate ischemia-related injuries in the myocardium, kidneys, and lower limbs following cardiovascular surgeries. Previous research has also demonstrated the neuroprotective effects of RIC in ischemia-reperfusion injuries of the nervous system. For instance, RIC significantly improves outcomes in cerebral small vessel disease (CSVD)-related acute stroke events and ameliorates cognitive impairments associated with CSVD. Moreover, the safety and efficacy of RIC have been validated in other conditions or procedures, such as aneurysmal subarachnoid hemorrhage (aSAH), intracranial atherosclerotic stenosis, and carotid artery stenting.
3. Research Hypothesis Current clinical studies on RIC have primarily focused on acute ischemic stroke (including large artery atherosclerosis and CSVD), spontaneous intracerebral hemorrhage, and subarachnoid hemorrhage. The Remote Ischemic Conditioning for Acute Stroke Trial (RESIST) indicated that RIC effectively improves outcomes in acute strokes related to CSVD, including reducing white matter hyperintensities, infarct volume, and modified Rankin Scale (mRS) scores. A clinical study conducted at the Mayo Clinic demonstrated the safety of remote ischemic preconditioning (RIPC) during intracranial aneurysm coiling. Our center's previous study on "Tirofiban and Procedure-Related Microemboli in Stent-Assisted Aneurysm Coiling" revealed that the incidence of procedure-related microembolic infarctions was 61.1% in the non-tirofiban group and 19.4% in the tirofiban-treated group. However, there is currently a lack of research on the use of RIC for procedure-related microembolic infarctions in stent-assisted aneurysm coiling.

This study aims to explore the efficacy of ischemic conditioning treatment, performed preoperatively and postoperatively, in reducing procedure-related microembolic infarctions during standard stent-assisted aneurysm coiling. The primary outcomes include the incidence of acute microembolic infarctions postoperatively and the incidence of symptomatic microembolic infarctions at one month following RIC.