Association between population changes and the number of endovascular thrombectomies.

Background: Randomized controlled trials have demonstrated the efficacy of mechanical thrombectomy (MT) for acute ischemic stroke. However, few studies indicate an association between the number of mechanical thrombectomies and population changes. We aimed to clarify the association between population changes and the number of mechanical thrombectomies for proper allocation of limited medical resources. Methods: We retrospectively analyzed data from 162 patients who underwent MT for large vessel occlusion at our hospitals and compared the number of mechanical thrombectomies per 100,000 person/year to population changes in five regions covered by our hospitals within 2015-2016 and 2017-2019. We performed a simple linear regression analysis to determine the association between population changes and the number of mechanical thrombectomies. Results: Overall, the number of mechanical thrombectomies increased from 15.1 to 19. However, a significant decrease was noted in Toya Lake and Sobetsu/Toyoura. Furthermore, there was a significant negative linear correlation between the overall population reduction rate and the number of mechanical thrombectomies and a positive linear correlation between the increased proportion of the population aged >65 years and the number of mechanical thrombectomies. Conclusion: The number of mechanical thrombectomies may decrease in areas where the overall population reduction rate exceeds 8% or the increased rate of the population aged >65 years is <4%. However, it is necessary to continue establishing a system for MT in areas that have yet to reach these levels.