Estimating Regional Demand for Mechanical Thrombectomy Based on Daily Case Distribution

Rapid provision of mechanical thrombectomy for acute large-vessel occlusion is indispensable for favorable outcomes; however, only a minority of eligible patients receive timely treatment. This health services research study examined the daily distribution of mechanical thrombectomy procedures within a regional system to provide a basis for estimating the treatment capacity required to meet demand. We collected daily mechanical thrombectomy case counts in Kochi prefecture, Japan, from January 2016 through December 2023. Assuming that mechanical thrombectomy cases occur independently and at random, we compared observed daily case distributions with a Poisson distribution. After confirming distributional fit, we estimated the daily mechanical thrombectomy capacity required to achieve 95% and 99% coverage of demand. To assess flexibility for emergency neuroendovascular care, we also analyzed daily admission counts for subarachnoid hemorrhage during the same period using identical methods. The mean annual number of mechanical thrombectomy cases was 161, corresponding to an overall rate of 23.2 cases per 100,000 persons per year. Daily mechanical thrombectomy case counts closely followed a Poisson distribution, with a maximum of 4 cases per day. Subarachnoid hemorrhage admissions exhibited a similar Poisson distribution. The estimated required daily mechanical thrombectomy capacity was 2-3 cases for 95% coverage and 3-4 cases for 99% coverage. Analysis of historical daily case counts enables estimation of region-specific mechanical thrombectomy demand and provides a practical framework for regional allocation of mechanical thrombectomy-capable physicians and facilities, although intraday timing data would allow more precise capacity modeling.