Tolga D. Dittrich, MD

Kamel H, Parikh NS, Chatterjee A, Kim LK, Saver JL, Schwamm LH, Zachrison KS, Nogueira RG, Adeoye O, Díaz I, et al. Access to Mechanical Thrombectomy for Ischemic Stroke in the United States. Stroke. 2021.

Mechanical thrombectomy (MT) helps prevent disability in patients with acute ischemic stroke due to large vessel occlusion. However, MT is not offered by every hospital since its performance requires special technical expertise. A key factor for functional outcome in the context of MT is the duration between symptom onset and successful recanalization. Therefore, the goal of acute stroke care is to avoid time loss, whether due to long transport to an MT-capable center or delayed diagnostic workups to detect a stroke whenever possible. Kamel et al. examined whether current systems of stroke care in the United States provide adequate access to MT.

From 2016 to 2018, discharge data from all nonfederal emergency departments and acute care hospitals in 11 U.S. states were examined. Hospitals were categorized according to their ability to provide MT as follows: (a) hubs (if they were able to perform MT); (b) gateways (if they referred patients who ultimately underwent MT); and (c) gaps (otherwise). Of 205,681 patients with ischemic stroke, 48.7% received care in a hub, 35.3% in a gateway, and 16.0% in an MT gap. Rural patients had particularly limited access, with 27.7% of these patients initially receiving care at hubs compared with 69.5% of urban patients. Thrombolysis could be initially performed in 93.8% of patients at gateways compared with 76.3% of patients at gaps. A substantial proportion of ischemic stroke patients in the U.S. did not have access to MT, even after accounting for interhospital transfers.

The core message of the paper is simple: Access to MT in the U.S. needs to be optimized. That said, it is important to acknowledge that there are geographic disparities in access to MT: (1) less than 50% of patients with ischemic stroke initially received care at facilities capable of performing MT; (2) there is an urban-rural divide with rural patients presenting more frequently in thrombectomy gaps that did not offer transfer to an MT-capable hospital; (3) even after accounting for interhospital transfer, approximately one-third of patients in rural areas presenting to MT gateways did not have access to MT; and (4) more patients at gateways had access to intravenous thrombolysis than patients presenting to gaps.

There are several potential starting points for measures to improve care. For one, the best possible allocation of available MT resources should be sought, especially through improved transfer protocols (e.g., telestroke triage systems, airborne transport by helicopter). These could help to facilitate more direct and rapid transfer to existing MT centers of patients with high NIHSS and thus a higher likelihood of large-vessel occlusion.

At the same time, the expansion of MT resources is an important issue. A reduction of MT transfer times could be achieved by technical upgrading of gateway centers. However, this is accompanied by an increased personnel effort for training and maintenance of interventional skills to ensure good functional results. Improving the consistency of bridging transport times in rural areas by widespread intravenous thrombolysis would likely be feasible with less effort and therefore desirable to improve functional outcomes.