Changes in Patient Volumes and Outcomes after Adding Thrombectomy Capability

Background and Purpose: With the rising demand for endovascular thrombectomy (EVT) and introduction of thrombectomy-capable stroke centers (TSC), there is interest among existing stroke hospitals to add EVT capability to attract and retain stroke patient referrals. In this work, we quantify changes in patient volumes and outcomes when adding EVT capability to an existing stroke center. Methods: In MATLAB 2017a Simulink, we simulate a 3-center system comprising an EVT-capable comprehensive stroke center, an EVT-incapable primary stroke center, and an EVT-incapable primary stroke center that gains EVT capability (TSC). We model these changes in 2 geographic settings (urban and rural) using 2 routing paradigms (Nearest Center and Bypass). In Nearest Center, patients are sent to the nearest center regardless of EVT capability. In Bypass, patients with severe strokes are sent to the nearest EVT-capable center, and all others are sent to the nearest center. Probability of good clinical outcome is determined by type and timing of treatment using outcomes reported in clinical trials. Results: Adding EVT capability in the Bypass model produced an absolute increase of 40.1% in total volume of patients with stroke and 31.2% to 31.9% in total volume of acute stroke treatments at the TSC. In the Nearest Center model, the total volume of patients with stroke did not change, but total volume of acute stroke treatment at the TSC had an absolute increase of 9.3% to 9.5%. Good clinical outcomes saw an absolute increase of 0.2% to 0.6% in the whole population and 0.3% to 1.8% in the TSC population. Conclusions: Adding EVT capability shifts patient and treatment volume to the TSC. However, these changes produce modest improvement in overall population health. Health systems should weigh relative hospital and patient benefits when considering adding EVT capability.