| 1. |
- Ahmed, Niaz, et al.
(författare)
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The SITS Open Study: A Prospective, Open Label Blinded Evaluation Study of Thrombectomy in Clinical Practice.
- 2021
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Ingår i: Stroke. - 1524-4628. ; 52:3, s. 792-801
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Tidskriftsartikel (refereegranskat)abstract
- We designed SITS (Safe Implementation of Treatment in Stroke) Open to determine benefit and safety of thrombectomy in clinical practice for large artery occlusion stroke, using selected stent retrievers plus standard care versus standard care alone.SITS Open was a prospective, open, blinded evaluation, international, multicenter, controlled, nonrandomized registry study. Centers lacking access to thrombectomy contributed controls. Primary end point was categorical shift in modified Rankin Scale score at 3 months in the per protocol (PP) population. Principal secondary outcomes were symptomatic intracranial hemorrhage, functional independency (modified Rankin Scale score 0-2) and death at 3 months. Patients independently evaluated by video-recorded modified Rankin Scale interviews blinded to treatment or center identity by central core laboratory were regarded as PP population. Propensity score matching with covariate adjusted analysis was performed.During 2014 to 2017, 293 patients (257 thrombectomy, 36 control) from 26 centers in 10 countries fulfilled intention-to-treat and 200 (170 thrombectomy, 30 control) PP criteria; enrollment of controls was limited by rapid uptake of thrombectomy. In PP analysis, median age was 71 versus 71 years, and baseline National Institutes of Health Stroke Scale 17 versus 17 in the thrombectomy and control arms, respectively. The propensity score matching analysis for PP showed a significant shift for modified Rankin Scale at 3 months favoring the thrombectomy group (odds ratio, 3.8 [95% CI, 1.61-8.95]; P=0.002). Regarding safety, there were 4 cases of symptomatic intracranial hemorrhage in the thrombectomy group (2.4%) and none in the control group.In clinical practice, thrombectomy for patients with large artery occlusion stroke is superior to standard of care in our study. Registration: URL: https://www.clinicaltrials.gov. Unique Identifier: NCT02326428.
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| 2. |
- Al-Saadi, Jonathan, et al.
(författare)
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Endovascular transplantation of mRNA-enhanced mesenchymal stromal cells results in superior therapeutic protein expression in swine heart
- 2024
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Ingår i: Molecular therapy. Methods & clinical development. - : Elsevier BV. - 2399-6951 .- 2329-0501. ; 32:2
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Tidskriftsartikel (refereegranskat)abstract
- Heart failure has a poor prognosis and no curative treatment exists. Clinical trials are investigating gene- and cell-based therapies to improve cardiac function. The safe and efficient delivery of these therapies to solid organs is challenging. Herein, we demonstrate the feasibility of using an endovascular intramyocardial delivery approach to safely administer mRNA drug products and perform cell transplantation procedures in swine. Using a trans-vessel wall (TW) device, we delivered chemically modified mRNAs (modRNA) and mRNA-enhanced mesenchymal stromal cells expressing vascular endothelial growth factor A (VEGF-A) directly to the heart. We monitored and mapped the cellular distribution, protein expression, and safety tolerability of such an approach. The delivery of modRNA-enhanced cells via the TW device with different flow rates and cell concentrations marginally affect cell viability and protein expression in situ. Implanted cells were found within the myocardium for at least 3 days following administration, without the use of immunomodulation and minimal impact on tissue integrity. Finally, we could increase the protein expression of VEGF-A over 500-fold in the heart using a cell-mediated modRNA delivery system compared with modRNA delivered in saline solution. Ultimately, this method paves the way for future research to pioneer new treatments for cardiac disease.
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| 3. |
- Chireh, Arvin, et al.
(författare)
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Micro-biopsy for detection of gene expression changes in ischemic swine myocardium : A pilot study
- 2021
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:4, s. e0250582-
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Tidskriftsartikel (refereegranskat)abstract
- Micro-endomyocardial biopsy (micro-EMB) is a novel catheter-based biopsy technique, aiming to increase flexibility and safety compared to conventional EMB. The technique was developed and evaluated in healthy swine. Therefore, the ability to detect disease related tissue changes could not be evaluated. The aim of the present pilot study was to investigate the ability to detect disease related gene expression changes using micro-EMB. Myocardial infarction was induced in three swine by coronary artery balloon occlusion. Micro-EMB samples (n = 164) were collected before, during, and after occlusion. RNA-sequencing was performed on 85 samples, and 53 of these were selected for bioinformatic analysis. A large number of responding genes was detected from the infarcted area (n = 1911). The early responding genes (n = 1268) were mostly related to apoptosis and inflammation. There were fewer responding genes two days after infarction (n = 6), which were related to extra-cellular matrix changes, and none after 14 days. In contrast to the infarcted area, samples harvested from a non-infarcted myocardial region showed considerably fewer regulated genes (n = 33). Deconvolution analysis, to estimate the proportion of different cell types, revealed a higher proportion of fibroblasts and a reduced proportion of cardiomyocytes two days after occlusion compared to baseline (p < 0.02 and p < 0.01, respectively. S5 File). In conclusion, this pilot study demonstrates the capabilities of micro-EMB to detect local gene expression responses at an early stage after ischemia, but not at later timepoints.
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| 4. |
- Jonsson, Magnus, et al.
(författare)
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Carotid Endarterectomy After Intracranial Endovascular Thrombectomy for Acute Ischaemic Stroke in Patients with Carotid Artery Stenosis
- 2022
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier. - 1078-5884 .- 1532-2165. ; 63:3, s. 371-378
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Recent randomised controlled trials demonstrated the benefit of intracranial endovascular thrombectomy (EVT) in acute ischaemic stroke. There is no consensus, however, on how to treat concomitant extracranial carotid artery stenosis after EVT. The aim of this study was to evaluate the outcome in patients treated with carotid endarterectomy (CEA) after EVT, comparing complication rates among patients undergoing CEA for stroke without previous EVT.Methods: This was a registry study of all patients (n = 3 780) treated with CEA after stroke in Sweden and the capital Helsinki region, Finland, from January 2011 to September 2020. Sixty three patients (1.7%; 0.5% 2011, 4.3% 2019) underwent EVT prior to CEA. The primary outcome was 30 day stroke and death rate.Results: The EVT+CEA group had major stroke as the qualifying neurological event (QNE) in 79%, but just 5.9% had this in the CEA only group (p < .001). Intravenous thrombolysis was administered before EVT in 54% of patients in the EVT+CEA group, but in just 12% in those receiving CEA only (p < .001). The combined stroke and death rate at 30 days for EVT+CEA was 0.0% (95% confidence interval [CI] 0.0 - 5.7). One patient had a post-operative TIA, none had post-operative intracerebral or surgical site haemorrhage. CEA was performed within a median of seven days (interquartile range 4, 15) after QNE, and 75% had CEA <= 14 days from QNE. The main reason to postpone CEA was an infarct larger than one third of the middle cerebral artery territory. The stroke and death rate in patients treated with CEA only was 3.7% (95% CI 3.2 - 4.4), CEA was performed a median of eight days after QNE, and in 79.7% in <= 14 days. The three year survival after EVT+CEA was 93% (95% CI 85 - 100), compared with 87% (95% CI 86 - 88) after CEA only. Cox regression analysis adjusting for age showed no increased all cause mortality after EVT+CEA (HR 1.3, 95% CI 0.6 - 2.7, p = .52).Conclusion: These results indicate that CEA is safe to perform after previous successful EVT for acute ischaemic stroke. Results were comparable with those undergoing CEA only, despite the EVT+CEA patients having more severe stroke symptoms prior to surgery, and timing was similar.
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| 5. |
- Keselman, Boris, et al.
(författare)
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Analysis and modelling of mistriage in the Stockholm stroke triage system
- 2022
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Ingår i: European Stroke Journal. - : Sage Publications. - 2396-9873 .- 2396-9881. ; 7:2, s. 126-133
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The Stockholm Stroke Triage System (SSTS) is a prehospital triage system for detection of patients eligible for endovascular thrombectomy (EVT). Assessment of hemiparesis combined with ambulance-hospital teleconsultation is used to route patients directly to the thrombectomy centre. Some patients are not identified and require secondary transport for EVT (undertriage) while others taken to the thrombectomy centre do not undergo EVT (overtriage). The aims of this study were to characterize mistriaged patients, model for and evaluate alternative triage algorithms.Patients and methods: Patients with suspected stroke transported by priority 1 ground ambulance between October 2017 and October 2018 (n = 2905) were included. Three triage algorithms were modelled using prehospital data. Decision curve analysis was performed to calculate net benefit (correctly routing patients for EVT without increasing mistriage) of alternative models vs SSTS.Results: Undertriage for EVT occurred in n = 35/2582 (1.4%) and overtriage in n = 239/323 (74.0%). Compared to correct thrombectomy triages, undertriaged patients were younger and had lower median NIHSS (10 vs 18), despite 62.9% with an M1 occlusion. In overtriaged patients, 77.0% had a stroke diagnosis (29.7% haemorrhagic). Hemiparesis and FAST items face and speech were included in all models. Decision curve analysis showed highest net benefit for SSTS for EVT, but lower for large artery occlusion (LAO) stroke.Discussion: Undertriaged patients had lower NIHSS, likely due to better compensated proximal occlusions. SSTS was superior to other models for identifying EVT candidates, but lacked information allowing comparison to other prehospital scales.Conclusion: Using prehospital data, alternative models did not outperform the SSTS in finding EVT candidates.
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| 6. |
- Keselman, Boris, et al.
(författare)
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The Stockholm Stroke Triage Project : Outcomes of Endovascular Thrombectomy Before and After Triage Implementation
- 2022
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Ingår i: Stroke. - : Lippincott Williams & Wilkins. - 0039-2499 .- 1524-4628. ; 53:2, s. 473-481
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The Stockholm Stroke Triage System (SSTS) is a prehospital algorithm for detection of endovascular thrombectomy (EVT)-eligible patients, combining symptom severity assessment and ambulance-to-hospital teleconsultation, leading to a decision on primary stroke center bypass. In the Stockholm Region (6 primary stroke centers, 1 EVT center), SSTS implementation in October 2017 reduced onset-to-EVT time by 69 minutes. We compared clinical outcomes before and after implementation of SSTS in an observational study.METHODS: We prospectively recruited patients transported by Code Stroke ambulance within the Stockholm region under the SSTS, treated with EVT during October 2017 to October 2019, and compared to EVT patients from 2 previous years.OUTCOMES: shift in modified Rankin Scale (mRS) scores, mRS score 0 to 1, mRS score 0 to 2, and death (all 3 months), National Institutes of Health Stroke Scale (NIHSS) score change 24-hour post-EVT, recanalization (Thrombolysis in Cerebral Infarction 2b-3), and symptomatic intracranial hemorrhage. mRS outcomes were adjusted for age and baseline NIHSS.RESULTS: Patients with EVT in the SSTS group (n=244) were older and had higher baseline NIHSS versus historical controls (n=187): median age 74 (interquartile range, 63-81) versus 71 (61-78); NIHSS score 17 (11.5-21) versus 15 (10-20). During SSTS, median onset-to-puncture time was 136 versus 205 minutes (P<0.001). Adjusted common odds ratio for lower mRS in SSTS patients was 1.7 (95% CI, 1.2-2.3) versus controls. During SSTS, 83/240 (34.6%) versus 44/186 (23.7%) reached 3-month mRS score 0 to 1 (P=0.014), adjusted common odds ratio 2.3 (95% CI, 1.4-3.6). Median NIHSS change 24-hour post-EVT was 6 versus 4 (P=0.005). Differences in Thrombolysis in Cerebral Infarction, symptomatic intracranial hemorrhage, and death were nonsignificant.CONCLUSIONS: With an onset to arterial puncture time reduction by 69 minutes, outcomes in thrombectomy-treated patients improved significantly after region-wide large artery occlusion triage system implementation. These results warrant replication studies in other geographic and organizational circumstances.
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| 7. |
- Mazya, Michael V., et al.
(författare)
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Implementation of a Prehospital Stroke Triage System Using Symptom Severity and Teleconsultation in the Stockholm Stroke Triage Study
- 2020
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Ingår i: JAMA Neurology. - : American Mathematical Society (AMS). - 2168-6149 .- 2168-6157. ; 77:6, s. 691-699
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Tidskriftsartikel (refereegranskat)abstract
- Importance: To our knowledge, it is unknown whether a prehospital stroke triage system combining symptom severity and teleconsultation could accurately select patients for primary stroke center bypass and hasten delivery of endovascular thrombectomy (EVT) without delaying intravenous thrombolysis (IVT).Objective: To evaluate the predictive performance of the newly implemented Stockholm Stroke Triage System (SSTS) for large-artery occlusion (LAO) stroke and EVT initiation. Secondary objectives included evaluating whether the Stockholm Stroke Triage System shortened onset-to-puncture time for EVT and onset-to-needle time (ONT) for IVT.Design, Setting, and Participants: This population-based prospective cohort study conducted from October 2017 to October 2018 across the Stockholm region (Sweden) included patients transported by first-priority ("code stroke") ambulance to the hospital for acute stroke suspected by an ambulance nurse and historical controls (October 2016-October 2017). Exclusion criteria were in-hospital stroke and helicopter or private transport. Of 2909 eligible patients, 4 (0.14%) declined participation.Exposures: Patients were assessed by ambulance nurses with positive the face-arm-speech-time test or other stroke suspicion and were evaluated for moderate-to-severe hemiparesis (≥2 National Institutes of Health stroke scale points each on the ipsilateral arm and leg [A2L2 test]). If present, the comprehensive stroke center (CSC) stroke physician was teleconsulted by phone for confirmation of stroke suspicion, assessment of EVT eligibility, and direction to CSC or the nearest primary stroke center. If absent, the nearest hospital was prenotified.Main Outcomes and Measures: Primary outcome: LAO stroke. Secondary outcomes: EVT initiation, onset-to-puncture time, and ONT. Predictive performance measures included sensitivity, specificity, positive and negative predictive values, the overall accuracy for LAO stroke, and EVT initiation.Results: We recorded 2905 patients with code-stroke transports (1420 women [49%]), and of these, 323 (11%) had A2L2+ teleconsultation positive results and were triaged for direct transport to CSC (median age, 73 years [interquartile range (IQR), 64-82 years]; 55 women [48%]). Accuracy for LAO stroke was 87% (positive predictive value, 41%; negative predictive value, 93%) and 91% for EVT initiation (positive predictive value, 26%; negative predictive value, 99%). Endovascular thrombectomy was performed for 84 of 323 patients (26%) with triage-positive results and 35 of 2582 patients (1.4%) with triage-negative results. In EVT cases with a known onset time (77 [3%]), the median OPT was 137 minutes (IQR, 118-180; previous year, 206 minutes [IQR, 160-280]; n = 75) (P < .001). The regional median ONT (337 [12%]) was unchanged at 115 minutes (IQR, 83-164; previous year, 115 minutes [IQR, 85-161]; n = 360) (P = .79). The median CSC IVT door-to-needle time was 13 minutes (IQR, 10-18; 116 [4%]) (previous year, 31 minutes [IQR, 19-38]; n = 45) (P < .001).Conclusions and Relevance: The Stockholm Stroke Triage System, which combines symptom severity and teleconsultation, results in markedly faster EVT delivery without delaying IVT.
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| 8. |
- Sandell, Mikael, et al.
(författare)
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3 D-printed micrograters for sampling of the blood vessel wall
- 2021
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Ingår i: 2021 34th IEEE international conference on micro electro mechanical systems (MEMS 2021). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 548-550
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Konferensbidrag (refereegranskat)abstract
- Endothelial cells lining blood vessels have phenotypic variations that indicate the health/disease status for a variety of conditions, including atherosclerosis and hypertension. Current sampling strategies lead to a high variation in the sampled amount, and we are not aware of sampling tools specifically targeting endothelial cells. Here, we present a new type of endovascular catheter for sampling of the blood vessel wall. The catheter is a 380 mu m nitinol tube over which 3D printed graters are threaded. The catheter is designed to be non-invasive during the axial motion and to interact with the blood vessel wall when rotated. Initial results indicate successful in-vivo sampling - with minimal blood contamination - of the wall of blood vessels less than 0.5 mm in diameter.
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| 9. |
- Sandell, Mikael, et al.
(författare)
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A novel noble metal stent coating reduces in vitro platelet activation and acute in vivo thrombosis formation : a blinded study
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Inherent to any stenting procedure is the prescription of dual antiplatelet therapy (DAPT) to reduce the platelet response. Clinical guidelines recommend 6–12 months of DAPT, depending on stent type, clinical picture and patient factors. Our hypothesis is that a nanostructured noble metal coating has the potential to reduce protein deposition and platelet activation. These effects would reduce subsequent thrombo-inflammatory reactions, potentially mitigating the need for an extensive DAPT in the acute phase. Here, a noble metal nanostructure coating on stents is investigated. Twelve pigs underwent endovascular implantation of coated and non-coated stents for paired comparisons in a blinded study design. The non-coated control stent was placed at the contralateral corresponding artery. Volumetric analysis of angiographic data, performed by a treatment blinded assessor, demonstrated a significant thrombus reduction for one of the coatings compared to control. This effect was already seen one hour after implantation. This finding was supported by in vitro data showing a significant reduction of coagulation activation in the coated group. This novel coating shows promise as an implant material addition and could potentially decrease the need for DAPT in the early phases of stent implementation.
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| 10. |
- Sandell, Mikael, et al.
(författare)
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An Ultraminiaturized MEMS Microbiopsy Tool for Trans Blood Vessel Wall Biopsies
- 2020
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Ingår i: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 10-12
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Konferensbidrag (refereegranskat)abstract
- We present a new type of microbiopsy tool (MBT) an order of magnitude smaller than commercially available biopsy catheters that, together with a trans-vessel wall catheter (Extroducer) successfully samples soft tissues with significantly less trauma to the tissue than commercial catheters. The MBT is mounted on a Nitinol wire. It features a gripping action that is actuated by the relative motion inside the Extroducer and has demonstrated repeated successful tissue sampling of approximately 500-1000 cells in ex-vivo tissue. This new catheter system can potentially allow super-selective, minimally invasive tissue sampling and transcriptomic analysis from hard to reach areas.
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| 11. |
- Sandell, Mikael, et al.
(författare)
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Endovascular Device for Endothelial Cell Sampling
- 2022
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Ingår i: Advanced NanoBiomed Research. - : Wiley. - 2699-9307 .- 2699-9307. ; 2:10, s. 2200023-2200023
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial cells play an important role in several vascular diseases, and molecular analysis of these cells could provide valuable information on underlying tissue status. However, no clinically established procedure for harvesting endothelial cells exists. A micro-3D-printed device adapted for endovascular techniques to harvest endothelial cells for transcriptomic analysis is presented. In vivo evaluation in swine (n = 6) yielded tissue samples in 60 out of 65 cases, of which 80% show a substantial amount of tissue. The cytological evaluation indicates high selectivity towards endothelial cells, and RNA-sequencing shows gene expression signatures consistent with vascular tissue. It is found that there are no short-term safety risks compared to operation with a control wire of equal dimensions and acute complications are not detected. If translated to clinical use, the device could enable increased understanding of early-stage endothelial cell-mediated disease progression and earlier diagnosis of diseases such as atherosclerosis.
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| 12. |
- Sandell, Mikael
(författare)
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Minimally Invasive Catheter-Based Technologies
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A simple incision procedure in a blood vessel makes the entire vascular system accessible. Through contrast injection and X-ray visualization, the vascular tree can be mapped and navigated through manual manipulation of thin tubes and wires. This utilization of the vasculature as internal pathways is commonly referred to as the endovascular technique. This technique can be used to deliver implants and drugs, retrieve problematic lesions or objects from the vasculature, or take tissue samples. Compared to open surgery, the advantage of this technique lies in the reduced invasiveness, ideally only leaving a small incision scar at the point of entry. Some interventions, however, are still associated with certain risks, requiring medication or complicating further interventions. The development of sequencing technologies presents an opportunity to improve and miniaturize devices, reducing invasiveness. This thesis aims to mitigate these risks and capitalize on the potential of next generation sequencing through microfabrication technologies, producing devices that are less invasive than current methods or that enable a new procedure.Initially, the aspect of endovascular heart biopsy is covered. The first work presents the fabrication and in vivo evaluation of a nitinol-based catheter device designed for extracting myocardial tissue. The device is fabricated through picosecond laser machining of nitinol tubes and wires, producing a device that is substantially smaller than what is currently used. The samples are evaluated and compared to samples extracted with conventional devices through RNA-Sequencing, verifying the proof of concept. The second work further emphasizes the device's functionality by evaluating it in a disease model of endomyocardial infarction. Tissue that is affected by the infarct and surrounding healthy tissue is extracted and compared in terms of its genetic expression. This comparison reveals a genetic discrepancy between the sick and healthy tissue, verifying the potential of using the device with RNA-sequencing for diagnostic purposes. The third work evaluates the safety aspects of the novel device in a head-to-head comparison with a conventional device. The study reveals a clear benefit of using the smaller device in terms of the complication rate during the procedure.The fourth work presents the fabrication and in vivo evaluation of another nitinol based catheter device designed for endothelial cell sampling. The device is fabricated through two-photon polymerization technologies, producing sub-mm brush structures mounted on a nitinol wire. Currently, there are no devices in clinical use that are capable of exclusively extracting endothelial cells. The novel device presents a solution for selective interaction with the innermost layer of the blood vessel. It represents an important step toward sampling endothelial cells for diagnostic and research purposes.The fifth and sixth works collectively present two different aspects of a third nitinol based catheter device designed to sample tissue from soft organs anywhere in the body. The device is fabricated using laser micromachining, grinding, and two-photon polymerization. The work is separated in terms of the in vivo evaluation and the technical solution. The technical aspects of the device are examined in terms of force generation in miniaturized catheter systems and the problems that arise in terms of mechanical scaling. These problems are solved by attaching pistons along the wire surface coupled with applied pressure to increase the force generated. The sampling with this device is realized, similar to the fourth work, with sub-mm brushes mountedon the wire. In vivo evaluation of this device reveals successful sampling of minute tissue quantities from the liver and kidney, in the size range of 10-100 cells per sample.The seventh work presents the in vivo and in vitro performance of a nanostructure coating on nitinol-based stents. Patients with a stent implant are prescribed an extensive medication regimen to counteract the metal implant's effects on the blood and surrounding tissue. This issue is being continuously targeted by new stent platforms, either with a drug-eluting polymer layer or by being resorbable by the body or through various other means. These implants all have a transient behavior, resulting in different issues over time. Paper VII presents an alternative approach to this problem by instead applying a nanostructure coating that is designed to interact with the blood to a much lesser degree, as demonstrated by CT-angiography and the measurement of multiple biomarkers.
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