Introduction: Mechanical thrombectomy (MT) improves outcomes for acute large vessel ischemic stroke but is time-sensitive and requires specialized infrastructure. Professional organizations and certification bodies have promulgated minimum procedural volume standards for centers and for individual proceduralists that perform MT, but it is unclear whether enforcing these requirements would decrease geographic access to MT.
Aim: We sought to evaluate the potential impact of applying a minimum procedural volume threshold on geographic access to MT.
Project Methods: We identified all hospital discharges for stroke where a mechanical thrombectomy procedure was performed at any non-federal hospital in Florida in 2019 using statewide hospital discharge data. We then generated geographic service area maps based on prespecified ground transport distances for the subset of hospitals that performed at least one MT and for those that performed at least 15 MTs that year. Then, using zip code centroids and patient-level discharge hospital data, we computed the proportion of acute stroke patients that lived within each of the generated service areas.
Results: A total of 105 of 297 hospitals performed MT, of those 51 (17%) were low-volume centers (1-14 MT/year) and 54 (18%) were high-volume centers (>15 MT/year). Higher volume centers accounted for nearly 95% of all MTs performed in the state. Most acute stroke patients (77.8%) lived within 20 miles of a hospital that performed at least one MT. Setting a minimum MT volume threshold of 15 would decrease the proportion of stroke patients living within 1 hour of a MT center from 86.9% to 77.4%.
Discussion: In 2019, most Florida stroke patients lived within a 1-hour ground transport time to a center that performed at least one MT, and nearly all lived within 3 hours of an MT center, irrespective of whether a minimum procedural volume threshold of 15 cases per year was applied or not. The proposed threshold of 15 MT annually does not profoundly affect geographic access to MT in Florida. Our study utilized home zip code for a patient’s location at the time of stroke, which is likely an oversimplification, and focused only on Florida which has more hospitals that previously received Joint Commission accreditations than any other state so the results may not be generalizable to other states with different stroke systems of care. This study gives as a sense of the impact of the proposed thresholds on geographic access, but it would be important to reassess geographic using a national scale.