As endovascular stroke treatment (EST) with mechanical thrombectomy has been established as a common treatment option for large vessel occlusion (LVO) acute ischemic stroke (AIS), stroke treatment has also become more challenging [
Our analysis is based on a prospective observational registry of all consecutive patients of the University Hospital RWTH Aachen (Aachen, Germany) tertiary stroke centre, who received any kind of reperfusion therapy for AIS between February 2010 and March 2015. We chose this timeframe to allow for comparable sample sizes in our subgroups (see below). Between February 2010 and March 2015, 1009 patients with AIS received reperfusion therapy. We excluded 70 cases of in-house strokes from our study. This left 939 patients with a community-onset stroke. Of those 337 were transferred to the angiography suite for EST. After interdisciplinary neurological-neuroradiological treatment decision, 15 of the 337 patients did not receive EST and were excluded from our subgroup analysis. This left 322 patients, who received EST in our institution and who were included in our study.
In order to determine the effect of a fulltime neuroradiological on-site service and workflow optimization with extensive documentation of procedural times, we compared procedural times of three phases: (1) phase 0: all patients, who were admitted before establishing a 24 h neuroradiological on-site service in May 2012, (2) phase 1: all consecutive patients, who were admitted after establishing a 24 h neuroradiological on-site service but before workflow optimization with extensive documentation of procedural times in February 2014, (3) phase 2: all remaining consecutive patients after workflow optimization (Figure
Schematic illustration of preinterventional workflow in our institution. RCC: rescue coordination centre; N: neurologist; NR: neuroradiologist; AN: anaesthesiologist; SU/NICU: stroke unit/neurological intensive care unit; CT: computed tomography; cCT: cranial CT; CTA: CT angiography; CTP: CT perfusion; ICH: intracranial/intracerebral haemorrhage; LVO: large vessel occlusion; IVRTPA: systemic thrombolysis; EST: endovascular stroke treatment. Dotted lines: phone calls. After the neurologist in charge is informed about a possible stroke by the rescue coordination centre, the neurologist informs the neuroradiologist in charge about the case. If a short clinical examination confirms the stroke, the anaesthesiologist on call is also informed and the patient is transferred to the CT suite, where the extent of stroke is assessed and an unenhanced CT is performed. In the meantime, the stroke unit or neurological intensive care unit is informed about the case. If there is no haemorrhage, and the patient fulfils standard inclusion criteria for thrombolysis, systemic thrombolysis is administered and a CT angiography is performed. If there is occlusion of a large cerebral artery, the interventionalist and the anaesthesiologist are informed and the patient is transferred to the angiography suite. In the angiography suite, there is parallel workflow with the interventionalist performing the groin puncture, while the anaesthesiologist intubates the patient.
“Stroke Check” form for interdisciplinary documentation of treatment related data. Initial NIHSS scores and follow-up mRS are documented on the back of the sheet.
The cornerstones of acute stroke treatment in our institution are (1) the neurological stroke team with vascular-experienced neurologists on-site 24 hours a day in the emergency department, (2) the supraregional comprehensive stroke unit (SU), (3) the neurological intensive care unit (NICU), and (4) the interventional neuroradiological team that is on-site during working-hours and on call (in a radius of 30 minutes) the rest of the time.
The rescue coordination centre informs the neurologist in charge about a stroke and the neurologist informs the neuroradiologist before the patient’s arrival in the emergency room. Only if a short clinical examination confirms the stroke, the anaesthesiologist in charge is also informed and the patient is transferred to the CT suite, where an unenhanced CT is performed. Next, in the absence of medical contraindications, systemic thrombolysis is administered, followed by CT angiography and a CT perfusion. Alternatively, magnetic resonance imaging (MRI) is performed as first- or second-line imaging if CT imaging is (expected to be) nonconclusive. A patient is regarded as eligible for EST when there is clinical stroke, absence of haemorrhage or large infarction, and proven and accessible LVO. In addition, salvageable brain tissue (mismatch between cerebral blood volume and cerebral blood flow on CT perfusion imaging) is also considered whenever other criteria for EST are ambiguous (for example, in wake-up strokes). EST can be initiated after the time window of 4.5 hours if cranial imaging indicates that there is clinically relevant salvageable brain tissue. In every case, the interventional neuroradiologist and an experienced vascular neurologist (on call) discuss and decide about the therapy. Decision-making is based on medical and social criteria. Whenever possible the patient and/or the patient’s relatives are involved in the decision-making process. If the decision to perform EST is made, the patient is transferred to the angiography suite. As all endovascular procedures are performed using general anaesthesia, there is parallel workflow with the interventionalist performing the groin puncture, while the anaesthesiologist intubates the patient. Standard endovascular treatment with and without stent retrievers is performed as reported previously [
After obtaining permission from our local ethics board, we assessed demographical data, clinical presentation (NIHSS) and disability (mRS) on admission, and disability at follow-up (mRS at discharge and day 90), cerebrovascular risk factors and primary as well as prophylactic use of antiplatelet/anticoagulant medication, and ischemic stroke aetiology (adapted from TOAST) [
Pearson’s
Ninety-six patients received interventional treatment before establishing a 24-7 neuroradiological service (phase 0). Fifty-three (55%) of these patients were admitted out-of-hours. Procedural times of patients admitted in working-hours and out-of-hours did not differ significantly. Median intervals for working-hours versus out-of-hours admissions were as follows: door-to-image: 26 versus 26 minutes (
Boxplots illustrating procedural times. Outliers are not illustrated. Phase 0: before establishing a 24 h neuroradiological on-site service in May 2012. Phase 1: after introduction of a 24 h neuroradiological on-site service but before workflow optimization with extensive documentation of procedural times in February 2014. Phase 3: after workflow optimization with extensive documentation of procedural times.
One hundred twenty-six patients received interventional treatment after introduction of a fulltime neuroradiological on-site service but before workflow optimization with extensive documentation of procedural times (phase 1). Seventy (56%) of these patients were admitted out-of-hours. Procedural times of patients admitted in working-hours and out-of-hours did not differ significantly. Median intervals for working-hours versus out-of-hours admissions were as follows: door-to-image: 26.5 versus 28 minutes (
One hundred patients received interventional treatment after workflow optimization with extensive documentation of procedural times (phase 2). Sixty-three (63%) of these patients were admitted out-of-hours. Procedural times of patients admitted in working-hours and out-of-hours did not differ significantly. Median intervals for working-hours versus out-of-hours admissions were as follows: door-to-image: 23 versus 21 minutes (
Procedural times improved slightly after establishing a 24-hour neuroradiological on-site service in May 2012 (Table
Overview of included patients. Phase 0: before establishing a 24 h neuroradiological on-site service in May 2012. Phase 1: after introduction of a 24 h neuroradiological on-site service but before workflow optimization with extensive documentation of procedural times in February 2014. Phase 2: after workflow optimization with extensive documentation of procedural times. NIHSS: national institute for health stroke scale; mRS: modified Rankin scale; ASPECTS Alberta stroke program early CT score. ICA: internal carotid artery; MCA: middle cerebral artery; ACA: anterior cerebral artery; VA: vertebral artery; BA: basilar artery; PCA: posterior cerebral artery. IA: intra-arterial. EST: endovascular stroke treatment. Values expressed as means ± standard deviation if not indicated otherwise.
Phase 0 | Phase 1 | Phase 2 |
|
|
---|---|---|---|---|
Demographics | ||||
Age (yr) ( |
|
|
|
0.673 |
Male sex ( |
52 (54.2%) | 63 (50.0%) | 43 (43.0%) | 0.284 |
|
||||
Medical history | ||||
Hypertension ( |
69 (71.9%) | 100 (79.4%) | 83 (82.0%) | 0.156 |
Diabetes ( |
26 (27.1%) | 22 (17.5%) | 35 (35.0%) | 0.011 |
Fat metabolism disorder ( |
36 (37.5%) | 38 (30.2%) | 23 (23.0%) | 0.087 |
Adiposity ( |
31 (32.3%) | 30 (23.8%) | 21 (21.0%) | 0.166 |
Nicotine ( |
22 (22.9%) | 35 (27.8%) | 20 (20.0%) | 0.381 |
Cardiovascular disease ( |
49 (51.0%) | 69 (54.8%) | 29 (29.0%) | <0.001 |
Atrial fibrillation ( |
47 (49.0%) | 61 (48.4%) | 51 (51.0%) | 0.924 |
Prior stroke ( |
16 (16.7%) | 23 (18.3%) | 19 (19.0%) | 0.910 |
Current antiplatelet use ( |
26/93 (28.0%) | 34/121 (28.1%) | 27/82 (32.9%) | 0.711 |
Current anticoagulant use ( |
8 (8.3%) | 16 (12.7%) | 16 (16.0%) | 0.264 |
|
||||
Clinical baseline | ||||
NIHSS on admission |
|
|
|
0.935 |
mRS on admission |
|
|
|
0.734 |
|
||||
Site of vessel occlusion | ||||
Anterior circulation (ICA, MCA, ACA) ( |
81 (84.4%) | 108 (85.7%) | 86 (86.0%) | 0.942 |
Posterior circulation (VA, BA, PCA) ( |
15 (15.6%) | 18 (14.3%) | 14 (14.0%) | |
Initial ASPECT score |
|
|
|
<0.001 |
|
||||
|
||||
Onset to door (min) |
|
|
|
0.247 |
Door to image (min) |
|
|
|
0.001 |
Image to puncture (min) |
|
|
|
<0.001 |
Puncture to revascularization (min) |
|
|
|
0.100 |
Door to revascularization (min) |
|
|
|
0.001 |
Onset to revascularization (min) |
|
|
|
0.244 |
|
||||
|
||||
Systemic thrombolysis ( |
69 (71.9%) | 87 (69.0%) | 67 (67.0%) | 0.759 |
IA thrombolysis ( |
34 (35.4%) | 28 (22.2%) | 9 (9.0%) | <0.001 |
Stent retriever ( |
77 (80.2%) | 118 (93.7%) | 97 (97.0%) | <0.001 |
|
||||
Outcome | ||||
Successful revascularization (TICI ≥ 2b) ( |
80 (83.3%) | 104 (82.5%) | 86 (86.0%) | 0.771 |
Good clinical outcome (mRS ≤ 2 d90) ( |
31/79 (39.2%) | 34/114 (29.8%) | 18/78 (23.1%) | 0.087 |
Death (d90) ( |
24/79 (30.4%) | 38/114 (33.3%) | 29/78 (37.2%) | 0.664 |
In out-of-hours admissions, additional workflow optimization with extensive documentation of procedural times had a significant impact on door-to-image (
In out-of-hours admissions, establishing a fulltime neuroradiological on-site service combined with workflow optimization with extensive documentation of procedural times resulted in significantly improved door-to-image (
With the introduction of a fulltime neuroradiological on-site service, we aimed to accelerate our procedural times and achieved slight improvements. We expected that the out-of-hours presence of a neuroradiologist would result in acceleration of image-to-puncture times and to a lesser degree also door-to-image times. However, a fulltime neuroradiological on-site service resulted only in a nonsignificant improvement of procedural times. A significant acceleration of procedural times could only be achieved when also the interdisciplinary workflow was optimized: in February 2014 we implemented a modified stroke workflow involving all participating parties beginning from the surrounding rescue coordination centres to our stroke unit and intensive care units [
In times of highly effective EST in AIS patients with LVO, it is mandatory to optimize all steps within the stroke rescue chain. Extensive intrahospital workflow optimization with specific standard operating procedures for all disciplines, that is, emergency physicians, neurologists, (neuro)radiologists, and anaesthesiologists, as well as for physicians, nurses, technical assistants, transportation, and registration staff, combined with constant feedback mechanisms, can dramatically improve procedural times and therewith outcome of patients [
Surprisingly, our measures had no impact on clinical outcome at follow-up. This is unexpected as clinical outcome is time-dependent [
Our results imply that a fulltime neuroradiological on-site service accelerates procedural times, but that changes are only significant if there is also workflow optimization of the entire interdisciplinary pre- and intrahospital stroke rescue chain. By combining a fulltime neuroradiological on-site service and workflow optimization via uniform documentation throughout the rescue chain, we were able to significantly reduce almost all procedural times of both working-hours and out-of-hours admissions without creating a weekend effect.
The authors declare that they have no conflicts of interest.