Intraoperative Real-Time Intrasaccular Pressure Monitoring: A Feasible Strategy to Optimize Coil Utilization and Individualize Flow Diverter Therapy for Unruptured Intracranial Aneurysms

Purpose This study investigates the clinical value of using flow diverter (FD) to treat patients with unruptured intracranial aneurysms (UIAs), specifically examining changes in aneurysm sac pressure and hemodynamics before and after intraoperative FD deployment to guide the need for additional coil embolization. The aim is to explore whether FD deployment sufficiently reduces aneurysm pressure, thereby minimizing or eliminating the need for coils. Methods A prospective cohort study enrolled 47 patients with UIAs undergoing FD treatment at the First Affiliated Hospital of Gannan Medical University from February 2023 to November 2024. Patients were divided into a pressure monitoring group (n = 23) and a control group (n = 24) based on whether real-time pressure monitoring was performed intraoperatively. The pressure monitoring group determined additional coil embolization based on changes in aneurysm sac pressure before and after FD deployment; the control group followed conventional experience-based procedures. Clinical characteristics, intraoperative parameters, coil packing density, and follow-up outcomes were compared between groups. The relationship between the dome-to-neck ratio ratio (DNR) and pressure changes was analyzed. Results Following FD deployment, the intra-aneurysmal systolic pressure (ISP) decreased by 11.8% ( P  = 0.041) in the pressure monitoring group, and the Intra-Aneurysmal Pressure (IAP) / Mean Arterial Pressure (MAP) ratio decreased by 5.56% ( P  = 0.019). DNR was significantly higher in the pressure-increase subgroup than in the decrease subgroup (1.47 ± 0.51 vs. 0.98 ± 0.32, P  < 0.001) and positively correlated with ΔIAP/ΔMAP ( r  = 0.69, P  < 0.001), suggesting DNR > 1.47 predicts increased intravascular pressure. The combination of pressure monitoring and coils reduced the rate of coiling by 19.4% compared to the control group, with significantly lower filling density (7.23% ± 1.37% vs. 17.89% ± 2.00%, P  = 0.001). Follow-up showed no statistically significant differences between groups in occlusion rates or outcomes (mRS ≤ 1). Conclusion Intraoperative real-time pressure monitoring safely and effectively guides coil embolization during FD deployment for UIA. A DNR > 1.47 indicates increased risk of intraluminal pressure rise after FD deployment; such patients require supplemental coils embolization to achieve a filling density of approximately 7.23% for pressure stabilization. This strategy helps reduce coil consumption and optimize individualized treatment plans.