Mechanical thrombectomy with Q catheter in stroke caused by primary and secondary distal and medium vessel occlusions.

BACKGROUND: The MIVI Q aspiration catheters have been shown to achieve significantly greater flow rates than other intracranial aspiration catheters in vitro. We describe our initial real-world experience with the MIVI Q catheter in emergent acute ischemic stroke (AIS) caused by distal and medium vessel occlusions (DMVO). METHODS: Data was collated from a prospectively maintained database which included patients from October 2019 to December 2022. Occlusion demographics, thrombectomy technique, reperfusion scoring, procedural complications and disposition were assessed. The primary outcome of interest was rate of successful reperfusion defined as thrombolysis in cerebral infarction (TICI) score 2b-3. Secondary outcomes included rate of first pass effect (FPE) and complications. RESULTS: We included 64 target occlusions in 51 patients. The Q catheter successfully reached the DMVO in all occlusions. Successful reperfusion was achieved in 49/64 (76.6%) occlusions, and TICI scores were similar for primary and secondary DMVOs (P value = 0.41). FPE was achieved in 39/64 (60.9%) occlusions and did not differ between primary and secondary DMVOs (P value = 0.13). Reperfusion hemorrhage occurred in 3/64 (4.7%) cases, small volume subarachnoid hemorrhage in 3/64 (4.7%) cases, and small hemorrhagic transformation in 1/64 (1.6%) cases; the rate of complications did not differ based on primary versus secondary DMVO (P value = 0.29). CONCLUSION: The MIVI Q catheter is both safe and effective. Our real-world experience supports the superior flow rates demonstrated in vitro and translates into high rates of successful reperfusion in AIS caused by DMVO in clinical practice.

pCONUS 2 and pCONUS 2-HPC in the treatment of wide-necked intracranial aneurysms: Multicentre UK experience.

BACKGROUND/PURPOSE: pCONUS 2 and pCONUS 2-HPC are neck-bridging devices that provide coiling support in the endovascular treatment of wide-necked intracranial aneurysms. To date, limited multicentre data has been published. This study provides the first pooled data from multiple UK centres regarding outcomes for these devices covering the periprocedural period to 6-month follow-up. MATERIALS/METHODS: This retrospective, single-arm study assessed 65 patients treated over 3 years from the time of procedure to 6 months post-procedure across four UK centres. Data collected included patient demographics, aneurysm characteristics and antiplatelet regimens. Outcome measures were angiographic results and procedure-related complications from the immediate periprocedural period to 6-month follow-up. RESULTS: Fifty-four unruptured (83.1%) and 11 ruptured (16.9%) aneurysms were treated. Fifty-five aneurysms were located in the anterior circulation (87.7%). There were four device-related intraprocedural complications: three cases of asymptomatic, temporary thrombus formation and one mortality associated with branch vessel occlusion and aneurysm re-bleeding in a ruptured case. There were no post-procedural device-related complications. Satisfactory occlusion was achieved in 58/65 procedures (89.2%) at time of treatment and in 44/60 (73.3%) at 6 months. Satisfactory occlusion correlated with aneurysm size and coiling packing density. Retreatment was required for five unruptured cases (7.7%) and was straightforward with the device in situ. CONCLUSION: pCONUS 2 and pCONUS 2-HPC have good short-term safety profiles. The use of pCONUS 2-HPC in the acute treatment of ruptured aneurysms with postprocedural SAPT is feasible. The devices have an intraprocedural complication rate of 4/65 (6.2%) across multiple UK centres, including a single death (1.5%).

The evolution of the bacterial luciferase gene cassette (lux) as a real-time bioreporter.

The bacterial luciferase gene cassette (lux) is unique among bioluminescent bioreporter systems due to its ability to synthesize and/or scavenge all of the substrate compounds required for its production of light. As a result, the lux system has the unique ability to autonomously produce a luminescent signal, either continuously or in response to the presence of a specific trigger, across a wide array of organismal hosts. While originally employed extensively as a bacterial bioreporter system for the detection of specific chemical signals in environmental samples, the use of lux as a bioreporter technology has continuously expanded over the last 30 years to include expression in eukaryotic cells such as Saccharomyces cerevisiae and even human cell lines as well. Under these conditions, the lux system has been developed for use as a biomedical detection tool for toxicity screening and visualization of tumors in small animal models. As the technologies for lux signal detection continue to improve, it is poised to become one of the first fully implantable detection systems for intra-organismal optical detection through direct marriage to an implantable photon-detecting digital chip. This review presents the basic biochemical background that allows the lux system to continuously autobioluminesce and highlights the important milestones in the use of lux-based bioreporters as they have evolved from chemical detection platforms in prokaryotic bacteria to rodent-based tumorigenesis study targets. In addition, the future of lux imaging using integrated circuit microluminometry to image directly within a living host in real-time will be introduced and its role in the development of dose/response therapeutic systems will be highlighted.

Acute ECG changes in a woman presenting to coronary care with fluctuating consciousness.

We present the case of a 67-year-old woman brought into the coronary care unit (CCU) with a suspected ST-segment elevation myocardial infarction (STEMI) due to lateral ST-segment elevation on her 12-lead electrocardiogram (ECG) and a significant troponin rise, but no reported chest pain and a fluctuating consciousness level. Whilst in CCU, she deteriorated further with a reduction in consciousness and sluggish pupillary reflexes, warranting urgent computed tomography (CT) of her brain, which confirmed extensive subarachnoid haemorrhage (SAH) with early evidence of hydrocephalus. She was therefore transferred to the local tertiary neurosurgical centre for endovascular coiling. ECG changes alongside a raised troponin are not uncommon findings in SAH and clinicians should exercise vigilance and consider urgent brain imaging in the absence of chest pain and presence of neurological deficit, to prevent adverse events from unnecessary antiplatelet or anticoagulant therapy, and invasive coronary angiography. SAH is a medical emergency and prompt recognition and referral for neurosurgical intervention is integral for optimal patient outcome.

Metric-Based Simulation Training to Proficiency for Endovascular Thrombectomy in Ischemic Stroke.

Ischemic stroke is one of the leading causes of death and long-term disability in the West. Mechanical revascularization techniques are considered the standard of care for large vessel occlusive stroke. Traditional apprenticeship models involve doctors training their skills on patients. Simulation platforms have long been recognized as an alternative to this. There has however been very little robust assessment of the training outcomes achieved on some of these platforms. At best, these simulations increase understanding of the procedural process and may help improve some technical skills; at worst they may instill bad habits and poor technique. The prerequisite of any simulation process must be to teach what to do, with which devices, in the correct sequence as well as what not to do. It should provide valid metric-based feedback to the trainee that is objective, transparent, and fair for formative and summative performance feedback. It should deliver a training program that measures the performance progress of trainees against expert benchmarks-benchmarks that represent an evidence-based peer-reviewed standard. In this paper, we present a perspective for PBP training for thrombectomy based on our experience with the process of procedure characterization, metric validation, and early experience of using this approach for proficiency training. Patient outcomes are not only determined by optimal performance in the Angio Suite but also by an efficient patient procedure pathway. There will be value in utilizing the PBP training standard not only for the procedure itself but also for the constituent elements of the stroke pathway to further improve treatment outcomes for ischemic stroke patients.

Endovascular treatment for vaccine-induced cerebral venous sinus thrombosis and thrombocytopenia following ChAdOx1 nCoV-19 vaccination: a report of three cases.

BACKGROUND: Vaccine-induced thrombosis and thrombocytopenia (VITT) is a rare complication following ChAdOx1 nCoV-19 vaccination. Cerebral venous sinus thrombosis (CVST) is overrepresented in VITT and is often associated with multifocal venous thromboses, concomitant hemorrhage and poor outcomes. Hitherto, endovascular treatments have not been reviewed in VITT-related CVST. METHODS: Patient records from a tertiary neurosciences center were reviewed to identify patients who had endovascular treatment for CVST in VITT. RESULTS: Patient records from 1 January 2021 to 20 July 2021 identified three patients who underwent endovascular treatment for CVST in the context of VITT. All were female and the median age was 52 years. The location of the CVST was highly variable. Two-thirds of the patients had multifocal dural sinus thromboses (sigmoid, transverse, straight and superior sagittal) as well as internal jugular vein thromboses. Intracerebral hemorrhage occurred in all patients; subarachnoid blood was noted in two of them, and intraparenchymal hemorrhage occurred in all. There was one periprocedural parenchymal extravasation which abated on temporary cessation of anticoagulation. Outcome data revealed a 90-day modified Rankin Scale (mRS) score of 2 in all cases. CONCLUSIONS: We demonstrate that endovascular treatment for VITT-associated CVST is feasible and can be safe in cases that deteriorate despite medical therapy. Extensive clot burden, concomitant hemorrhage, rapid clinical progression and persistent rises in intracranial pressure should initiate multidisciplinary team discussion for endovascular treatment in appropriate cases.

Aortic and supra-aortic arterial tortuosity and access technique: Impact on time to device deployment in stroke thrombectomy.

BACKGROUND: Longer intervals to reperfusion in patients treated with mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO) stroke are associated with worse outcomes and influenced by the operator's ability to navigate individual anatomy. Our aims were to assess the impact of time from puncture to first deployment of the MT device (DT) on technical and clinical outcomes, develop an Anatomical Assessment for Mechanical Thrombectomy Score (ASMETS) that could predict DT and assess how different methods of intracranial access (coaxial-direct or exchange) influence this. METHODS: Retrospective review of a prospective database of patients treated with MT for ELVO between November 2015 and August 2018. CTAs were assessed for ASMETS. Intracranial access technique was at the discretion of the operator. Technical and clinical outcomes and complications were recorded. Linear and logistic regression analysis was performed. RESULTS: 92 patients were included. The impact of DT on clinical outcomes was significant. An unfavourable ASMET score is significantly associated with longer DT (p = 0.002) and linear regression showed DT time can be predicted by ASMETS - F(1,90) = 6.182, p = 0.015. No difference was demonstrated between different access techniques. CONCLUSION: CTA-based ASMETS can predict time between arterial puncture and deployment of the mechanical thrombectomy device in stroke patients, irrespective of the technique used to catheterise the target ICA. This could inform the operator in preparing appropriate strategies to overcome challenging vascular anatomy in patients undergoing MT.

A systematic review and meta-analysis of observational evidence for the use of bailout self-expandable stents following failed anterior circulation stroke thrombectomy.

BACKGROUND: The crucial role of thrombectomy in the management of emergent large vessel occlusive stroke is not disputed but there is a technical failure rate in a significant minority of patients whose outcomes are often poor. Our objective was to perform a systematic review and meta-analysis to assess the safety and efficacy of permanent self-expandable stent deployment as a bailout procedure in cases of failed anterior circulation thrombectomy. METHODS: Two independent reviewers searched the Pubmed (Medline) database for studies reporting outcomes following failed endovascular thrombectomy with subsequent rescue therapy employing self-expandable stents. RESULTS: Eight studies (one prospective, seven retrospective) originating from Europe, Asia, and America comprising 160 patients met the inclusion criteria. Estimated baseline National Institutes of Health Stroke Scale score was 17.1 (95% CI 15.7 to 18.4). Following failed thrombetcomy and stent deployment, the rate of favorable outcome (modified Rankin Scale score 0-2) was 43% (95% CI 34% to 53%). Pooled mortality was 21% (95% CI 13% to 33%). Successful recanalization (Thrombolysis in Cerebral Infarction (TICI) 2b-3 or Thrombolysis in Myocardial Infarction (TIMI) 2-3) was 71% (95% CI 63% to 77%). Symptomatic intracerebral hemorrhage was seen in 12% (95% CI 7% to 18%). The Solitaire stent (Medtronic) was the most commonly deployed stent following failed thrombectomy attempts (66%; 95% CI 31% to 89%). Pre- or post-stent angioplasty was performed in 39%of patients (95% CI 29% to 48%). Glycoprotein IIb/IIIa inhibitors were used in 89% (95% CI 71% to 97%). 95% of patients received postprocedural antiplatelet therapy. CONCLUSION: A rescue stent procedure seems reasonable as a last resort following failed thrombectomy but currently the level of evidence is limited. Prospective registries may aid in guiding future recommendations.

Validation studies of virtual reality simulation performance metrics for mechanical thrombectomy in ischemic stroke.

INTRODUCTION: Mechanical thrombectomy (MT) has transformed the treatment of ischemic stroke. However, patient access to MT may be limited due to a shortage of doctors specifically trained to perform MT. The studies reported here were done to (1) develop, operationally define, and seek consensus from procedure experts on the metrics which best characterize a reference procedure for the performance of an MT for ischemic stroke and (2) evaluate their construct validity when implemented in a virtual reality (VR) simulation. METHODS: In study 1, the metrics for a reference approach to an MT procedure for ischemic stroke of 10 phases, 46 steps, and 56 errors and critical errors, were presented to an international Delphi panel of 21 consultant level interventional neuroradiologists (INRs). In study 2, the metrics were used to assess 8 expert and 10 novice INRs performing a VR simulated routine MT procedure. RESULTS: In study 1, the Delphi panel reached consensus on the appropriateness of the procedure metrics for a reference approach to MT in ischemic stroke. Group differences in median scores in study 2 demonstrated that experienced INRs performed the case 19% faster (P=0.029), completed 40% more procedure phases (P=0.009), 20% more steps (P=0.012), and made 42% fewer errors (P=0.016) than the novice group. CONCLUSIONS: The international Delphi panel agreed metrics implemented in a VR simulation of MT distinguished between the computer scored procedure performance of INR experts and novices. The studies reported here support the demonstration of face, content, and construct validity of the MT metrics.

Cervical ICA pseudo-occlusion on single phase CTA in patients with acute terminal ICA occlusion: what is the mechanism and can delayed CTA aid diagnosis?

BACKGROUND: Single-phase CT angiography (CTA) forms the basis of hyperacute stroke imaging but many patients with terminal internal carotid artery (ICA) occlusion exhibit a pseudo-occlusion of the cervical ICA whereby a column of unopacified blood mimics a tandem cervical ICA lesion. We aimed to investigate the utility of a delayed phase acquisition to aid identification of a pseudo-occlusion and investigated the mechanism for this imaging artefact. METHODS: Thirteen patients with a pseudo-occlusion were compared with 13 patients without. CT, CTA, and digital subtraction angiographic images were reviewed by two interventional neuroradiologists for extension of thrombus into the ophthalmic segment, filling of the posterior communicating artery and ophthalmic artery, and for extension of contrast beyond the cervical segment and outline of the proximal clot surface by contrast on delayed imaging performed at 40 or 80 s. RESULTS: Those with a pseudo-occlusion demonstrated more frequent thrombus extension into the ophthalmic segment (100% vs 23%, P=0.0001), less frequent filling of the posterior communicating artery (15% vs 85%, P=0.0012), and less frequent filling of the ophthalmic artery (15% vs 92%, P=0.0002) compared with those without a pseudo-occlusion. Delayed CTA imaging showed contrast beyond the cervical segment and meeting the proximal clot face in 2/11 patients. Each of these two patients showed patency of the posterior communicating artery origin. CONCLUSION: Thrombus extension into the ophthalmic segment and patency of the posterior communicating artery and ophthalmic artery seem to govern whether a patient with a terminal ICA occlusion exhibits a pseudo-occlusion. Delayed imaging was of limited value in identification of a pseudo-occlusion.

Safety profile of an 8F femoral arteriotomy closure using the Angio-Seal device in thrombolysed acute stroke patients undergoing thrombectomy.

Background The relationship between bridging thrombolysis and femoral access site complications after mechanical thrombectomy remains contested. Use of a closure device could minimise bleeding complications. This study aimed to elucidate the rate of access site complications in a cohort of patients treated using an 8F groin sheath with subsequent closure using the Angio-Seal to assess safety and the impact of bridging thrombolysis on access site complication rate. Methods All patients with large vessel occlusive stroke treated between 2014 and 2017 with thrombectomy with or without bridging thrombolysis were reviewed. A prospectively acquired departmental database was used to obtain baseline data, and the radiology information and haematology reporting systems were used to record imaging or transfusion relating to subsequent access site complications. Results Seventy-five patients treated with thrombectomy alone were compared to 70 patients treated with prior intravenous thrombolysis. All had an 8F femoral sheath placed for arterial access, and all underwent attempted haemostasis with an 8F Angio-Seal. Two patients (1.14%) suffered Angio-Seal device failure necessitating manual pressure. One patient (0.6%) suffered a small femoral pseudo-aneurysm. No retroperitoneal haemorrhage, haematoma requiring transfusion, ipsilateral deep-vein thrombosis or ipsilateral acute limb ischaemia was encountered. There was no significant difference in the rate of haemorrhagic, ischaemic or infective complications between those treated with bridging thrombolysis or thrombectomy alone. Conclusion Use of the Angio-Seal closure device for 8F femoral access is safe in acute stroke patients. Intravenous thrombolysis prior to endovascular thrombectomy does not significantly alter femoral access site complication rate if this approach is used.