Optimization of the management and triage of stroke patients in the acute phase

Acute ischemic stroke (AIS) due to a large vessel occlusion (LVO) is a devastating disease associated with high rates of morbidity and mortality. Currently, the standard of care for patients presenting with a LVO is removal of the clot with specialized catheters (endovascular treatment). Although endovascular treatment has substantially improved the outcomes of AIS patients, still roughly 50% of patients suffer from severe disability or death. Due to the very high time dependency of the treatment effect, strategies to reduce time to treatment to a minimum are highly warranted. As of now no consensus exists on the best possible triage strategy for suspected AIS patients. One possible approach to reduce time delays within the hospital is to transport patients directly from the emergency room to the angiography room for diagnosis of a vessel occlusion and subsequent treatment (One-Stop management) instead of transporting the patient first to the CT room and after diagnosis of a vessel occlusion to the angiography room for treatment (traditional triage pathway). Imaging in the One-Stop management pathway is done with flat detector CT (FDCT) instead of traditional multidetector CT (MDCT). Many clinicians are still hesitant to use this triage pathway due to missing data and lower confidence in the quality of FDCT imaging. Therefore, several research gaps and challenges remain for the optimization of the management and triage of suspected stroke patients in the acute phase, of which we selected three aspects to focus on in the following topics that comprise this PhD thesis.
The first topic focusses on the radiation burden caused by alternative imaging modalities in AIS patients. While flat-detector CT (FDCT) imaging becomes more and more acknowledged as an alternative imaging modality for the diagnosis of an AIS and an LVO, the effective dose to patient of FDCT protocols was not evaluated systematically. For the widespread implementation of FDCT as an imaging modality it must be secured that no excess harm is caused due to a higher burden of radiation. We therefore measured the effective dose to patient and the eye lens dose on two angiography systems and compared it with measurements on the latest generation of commonly used MDCT systems.
The second topic focusses on the presentation of suspected AIS patients. As there is no high-level evidence for the implementation of a One Stop management approach, we are planning to conduct a randomized controlled trial. However, for the conduct of such a trial it is important to have reliable information of the expected patient cohort. We therefore analyzed all patients presenting to a tertiary university hospital in one year to give an estimate on the patient collectives expected for such a trial. The data can further be used to plan resources accordingly in times of expanding indications for endovascular treatment of AIS patients.
The third and final topic summarizes the available evidence regarding One-Stop management and direct to angiography approaches in a systematic review and meta-analysis. It gives an overview over the research conducted so far in this field and is the foundation for the planning of a randomized controlled trial evaluating a One-Stop management approach for suspected AIS patients.