Large Tissue Debris Causing Cerebral Embolism After Transcatheter Aortic Valve Replacement.

Cerebral vascular embolism is one of the complications of transcatheter aortic valve replacement (TAVR). Thrombolytic therapy is not expected to be effective when embolic material consists of a large tissue fragment. Instead, mechanical aspiration may be more effective therapy for acute cerebral infarction after TAVR. Here, we describe the case of an 87-year-old woman with aortic valve stenosis and heart failure who underwent TAVR using a self-expandable valve. Acute cerebral infarction with left middle cerebral artery occlusion caused by a large tissue fragment developed after the procedure.

Cerebral Embolism and MINOCA Secondary to Left Atrial Myxoma after Occlusion of Atrial Septal Defect by Amplatzer Occluder: A Case Report.

Primary heart tumors are rare, with atrial myxomas being the most common type. Atrial myxomas can lead to embolisms, heart obstruction, and systemic symptoms. Herein, we report a case of 72-year-old woman who presented with a left atrial myxoma at the atrial septal defect occluder, a new acute cerebral infarction, and MINOCA (myocardial infarction with no obstructive coronary atherosclerosis). Left atrial myxoma is a common primary cardiac tumor; however, left atrial myxomas arising after percutaneous atrial septal defect occlusion are rare. Additionally, the patient presented with a new case of multiple systemic emboli. The patient underwent surgical resection of a left atrial myxoma, occluder, and left atrium, and atrial septal repair, and was discharged with good recovery for outpatient follow-up. The possibility of a cardiac tumor, especially an atrial myxoma, which can lead to a series of complications, should be considered at the closure site after percutaneous atrial septal closure. Therefore, active surgical treatment and long-term follow-up are warranted in such cases.

[Cerebral Embolism:Endovascular Techniques and Devices].

Thrombectomy has proven its efficacy in several randomized clinical trials. Although considerable clinical evidence supports its efficacy, the optimal device or technique has not been proven. There is a diversity of devices and techniques; therefore, we need to know about them and choose suitable ones. Recently, a combined technique with a stent retriever and aspiration catheter has become common. However, no evidence to support the superiority of the combined technique in improving patient outcomes compared with the stent retriever alone.

Impact of routine use of a cerebral protection device on the TAVR procedure and its short-term outcomes: a single-centre experience.

BACKGROUND: Stroke is a major concern in transcatheter aortic valve replacement (TAVR). The introduction of a cerebral protection devices may counteract the evolution towards minimally invasive TAVR. At this time, there is insufficient data to support the routine use of these devices. METHODS: We aimed to evaluate the outcome of the routine use of the Sentinel Cerebral protection system® (CPS) in patients undergoing TAVR, after completing a CT-based screening process for feasibility of Sentinel implantation. We report our initial experience with the routine implementation of the Sentinel CPS in all anatomically suitable patients undergoing TAVR. We retrospectively compared the procedural characteristics and outcomes between all TAVR patients treated with (n = 78) and without (n = 79) intended Sentinel. RESULTS: The Sentinel CPS could successfully be deployed in 99% of intended cases after CT feasibility screening. TAVR procedures with Sentinel CPS were not longer than procedures without Sentinel use (89 ± 20 versus 120 ± 50 min, p = 0.007). Sentinel CPS use was not associated with an increased risk of procedural complications. Stroke was observed in none (0%) of the Sentinel CPS patients, and in 6.3% of the non-Sentinel CPS patients (p = 0.05). The finding of stroke was associated with a high risk of early postprocedural mortality: 60% of stroke patients died within 3 months. CONCLUSION: Routine use of the Sentinel CPS in CT-screened TAVR patients is feasible with high procedural success, without significant adverse events and without counteracting the evolution towards minimally invasive TAVR. Clinically relevant stroke was observed in none of the Sentinel CPS patients.

[Surgery for a Massive Left Atrial Myxoma, Four Hours after a Thrombectomy for a Cerebral Embolism:Report of a Case].

A 48-year-old female patient was transferred with dysarthria and left-sided hemiplegia. Contrast-enhanced computed tomography revealed occlusion of the first branch of the right middle cerebral artery, for which an emergency thrombectomy was successfully performed within 2 hours of patient's initial symptoms. Postoperatively, transthoracic echocardiography revealed a massive mobile left atrial mass, measuring approximately 65×30 mm, a part of which moved in and out of the mitral valve without significant mitral regurgitation. Embolisms to the kidneys and the spleen were demonstrated. Another emergency cardiac surgery was performed, 4 hours after the thrombectomy, to resect the mass from the fossa oval with the atrial septum;the defect was closed using autologous pericardium. The histopathological findings of the specimen were consistent with a myxoma. The patient completely recovered and was discharged when ambulatory. We have discussed the importance of the timing of surgical intervention in the context of patients undergoing cardiac surgery after a cerebral embolism.

In vitro analysis of mechanism of pulsed-laser thrombolysis.

Thrombolytic therapy in the treatment of cardiogenic acute cerebral embolism caused by coagulated blood carries the risk of hemorrhagic complications, and there is a need to develop safer and more reliable treatment methods. Laser thrombolysis therapy, which utilizes the difference in energy absorption between the thrombus and the arterial wall, has shown promise as a new treatment method because it can selectively act only on the thrombus. It has not been applied clinically, however, and one of the main reasons for this is that its underlying mechanism has not been elucidated. We developed a pulse laser thrombolysis system for treating cerebral blood vessels that consists of a diode-pumped solid-state neodymium-yttrium aluminum garnet laser, which has excellent stability and maintainability and is suitable for clinical applications coupled to a small-diameter optical fiber. Moreover, we analyzed the mechanisms that occur during pulsed laser irradiation of transparent glass tubes and gelatin phantoms. We found that bubbles form as a thermal effect in addition to ablation of the pulsed laser irradiation. Furthermore, we detected no shock waves or water jets associated with the bubbles. We analyzed the bubbles' dynamics and growth rate, and their effect on a rabbit blood clot phantom. We concluded that the bubbles generated by the laser irradiation physically cut the thrombus and thereby had a thrombectomy effect. We believe that this study will clarify the mechanism of laser thrombolysis therapy and contribute greatly to the realization of its clinical application.

Neurologic Dysfunction and Neuroprotection in Transcatheter Aortic Valve Implantation.

Transcatheter aortic valve implantation (TAVI) is a fast-growing procedure. Expanding to low-risk patients, it has surpassed surgical aortic valve implantation in frequency and has been associated with excellent outcomes. Stroke is a devastating complication after transcatheter aortic valve implantation. Silent brain infarcts identified by diffusion-weighted magnetic resonance imaging are present in most patients following TAVI. Postoperative delirium and cognitive dysfunction are common neurologic complications. The stroke and silent brain infarcts are likely caused by particulate emboli released during the procedure. Intravascularly positioned cerebral embolic protection devices are designed to prevent debris from entering the aortic arch vessels to avoid stroke. Despite promising design, randomized clinical trials have not demonstrated a reduction in stroke in patients receiving cerebral embolic protection devices. Similarly, the association of cerebral embolic protection devices with silent brain infarcts, postoperative delirium, and cognitive dysfunction is uncertain. Monitored anesthesia care or conscious sedation is as safe as general anesthesia and is associated with lower cost, but different anesthetic techniques have not been shown to decrease stroke risk, postoperative delirium, or cognitive dysfunction. Anesthesiologists play important roles in providing perioperative care including management of neurologic events in patients undergoing TAVI. Large randomized clinical trials are needed that focus on the correlation between perioperative interventions and neurologic outcomes.

Safety and efficacy of cerebral embolic protection devices in patients undergoing transcatheter aortic valve replacement: a meta-analysis of in-hospital outcomes.

The evidence regarding the impact of cerebral embolic protection devices (EPDs) on outcomes following transcatheter aortic valve replacement (TAVR) is limited. The objective of this study was to evaluate in-hospital outcomes with the use of cerebral EPDs in TAVR. We performed a comprehensive EMBASE and PUBMED search to investigate randomized control studies or propensity score-matched retrospective studies which assessed patients undergoing TAVR with or without EPD up to April 2021. Endpoints of interest were in-hospital mortality, stroke, acute kidney injury, pacemaker implantation, major bleeding, vascular complication, length of stay. Ten studies involving 173,002 patients with EPD (n = 16,898, 9.8%) and those without (n = 156,104, 90.2%) fulfilled the inclusion criteria. The use of EPD was associated with significantly lower risk of in-hospital stroke (odds ratio [95% confidential interval]: 0.64 [0.46; 0.89]), but similar rate of in-hospital mortality (odds ratio [95% confidential interval]: 0.75 [0.54; 1.05]). No differences were observed in acute kidney injury, pacemaker implantation, major bleeding, vascular complication, length of stay. EPD during TAVR was associated with lower in-hospital stroke but did not affect procedural complications and length of stay.

An Older Thrombus Delays Reperfusion after Mechanical Thrombectomy for Ischemic Stroke.

BACKGROUND: Thrombosis is a dynamic process, and a thrombus undergoes physical and biochemical changes that may alter its response to reperfusion therapy. This study assessed whether thrombus age influenced reperfusion quality and outcomes after mechanical thrombectomy for cerebral embolism. METHODS: We retrospectively evaluated 185 stroke patients and thrombi that were collected during mechanical thrombectomy at three stroke centers. Thrombi were pathologically classified as fresh or older based on their granulocytes' nuclear morphology and organization. Thrombus components were quantified, and the extent of NETosis (the process of neutrophil extracellular trap formation) was assessed using the density of citrullinated histone H3-positive cells. Baseline patient characteristics, thrombus features, endovascular procedures, and functional outcomes were compared according to thrombus age. RESULTS: Fresh thrombi were acquired from 43 patients, and older thrombi were acquired from 142 patients. Older thrombi had a lower erythrocyte content (p < 0.001) and higher extent of NETosis (p = 0.006). Restricted mean survival time analysis revealed that older thrombi were associated with longer puncture-to-reperfusion times (difference: 15.6 minutes longer for older thrombi, p = 0.002). This association remained significant even after adjustment for erythrocyte content and the extent of NETosis (adjusted difference: 10.8 minutes, 95% confidence interval [CI]: 0.6-21.1 minutes, p = 0.039). Compared with fresh thrombi, older thrombi required more device passes before reperfusion (p < 0.001) and were associated with poorer functional outcomes (adjusted common odds ratio: 0.49; 95% CI: 0.24-0.99). CONCLUSION: An older thrombus delays reperfusion after mechanical thrombectomy for ischemic stroke. Adding therapies targeting thrombus maturation may improve the efficacy of mechanical thrombectomy.

Failure modes and effects analysis of mechanical thrombectomy for stroke discovered in human brains.

OBJECTIVE: Despite advancement of thrombectomy technologies for large-vessel occlusion (LVO) stroke and increased user experience, complete recanalization rates linger around 50%, and one-third of patients who have undergone successful recanalization still experience poor neurological outcomes. To enhance the understanding of the biomechanics and failure modes, the authors conducted an experimental analysis of the interaction of emboli/artery/devices in the first human brain test platform for LVO stroke described to date. METHODS: In 12 fresh human brains, 105 LVOs were recreated by embolizing engineered emboli analogs and recanalization was attempted using aspiration catheters and/or stent retrievers. The complex mechanical interaction between diverse emboli (elastic, stiff, and fragment prone), arteries (anterior and posterior circulation), and thrombectomy devices were observed, analyzed, and categorized. The authors systematically evaluated the recanalization process through failure modes and effects analysis, and they identified where and how thrombectomy devices fail and the impact of device failure. RESULTS: The first-pass effect (34%), successful (71%), and complete (60%) recanalization rates in this model were consistent with those in the literature. Failure mode analysis of 184 passes with thrombectomy devices revealed the following. 1) Devices loaded the emboli with tensile forces leading to elongation and intravascular fragmentation. 2) In the presence of anterograde flow, small fragments embolize to the microcirculation and large fragments result in recurrent vessel occlusion. 3) Multiple passes are required due to recurrent (15%) and residual (73%) occlusions, or both (12%). 4) Residual emboli remained in small branching and perforating arteries in cases of alleged complete recanalization (28%). 5) Vacuum caused arterial collapse at physiological pressures (27%). 6) Device withdrawal caused arterial traction (41%), and severe traction provoked avulsion of perforating and small branching arteries. CONCLUSIONS: Biomechanically superior thrombectomy technologies should prevent unrestrained tensional load on emboli, minimize intraluminal embolus fragmentation and release, improve device/embolus integration, recanalize small branching and perforating arteries, prevent arterial collapse, and minimize traction.

Open surgical embolectomy for cardiogenic cerebral embolism: Technical note and its advantages.

BACKGROUND AND IMPORTANCE: In cardiogenic cerebral embolism, early recanalization is the most important factor for good prognosis. However, endovascular thrombectomy often fails to achieve recanalization. We present an open surgical embolectomy technique and discuss its advantages. CLINICAL PRESENTATION: A 79-year-old woman developed right hemiparesis and severe aphasia. Magnetic resonance imaging revealed an acute cerebral infarction caused by left middle cerebral artery (MCA) occlusion. We attempted endovascular thrombectomy but failed because it was impossible to guide the catheter to the occlusion site. Hence, we converted to open surgical embolectomy. Sylvian fissure was widely opened. After confirming the range of thrombosis using indocyanine green videoangiography (ICGVAG), the proximal and distal arteries were secured, and a temporary clip was placed on the distal M2 to prevent distal thrombosis migration. MCA was cut approximately 3 mm from the bifurcation, and thrombosis was removed using micro-forceps. The proximal clip was simultaneously inserted but was not clamped because the thrombus was extruded by proximal vascular flow. Immediately after removing the thrombus, intense bleeding occurred from the proximal flow. An assistant clamped the proximal artery using the prepared clip, and the incised area of MCA was sutured using 9-0 threads. We finally confirmed blood flow after recanalization using ICGVAG. The time from skin incision to recanalization was 27 min. After the procedure, the patient developed slight aphasia but had no hemiparesis and was later transferred to a rehabilitation hospital. CONCLUSION: Open surgical embolectomy may be a secondary rescue treatment option in the case of endovascular thrombectomy failure.

A Single-Center Experience of Endovascular Treatment in Subtypes of Basilar Artery Occlusion: Embolization Caused by Tandem Vertebral Artery Stenosis May Be Associated with Better Outcomes.

OBJECTIVE: Basilar artery occlusion (BAO) is a severe condition with high mortality. However, surgical procedures and outcomes of BAO with different pathologic subtypes have not been fully clarified. This study compared the surgical procedures and clinical outcomes of mechanical thrombectomy in different subtypes of BAO. METHODS: Eighty-six patients with acute BAO receiving endovascular treatment between October 2015 and July 2019 were retrospectively analyzed and placed in 3 groups: pure embolism (group 1), arterial-arterial embolism from steno-occlusion of the tandem vertebral artery (group 2), and in situ atherosclerotic thrombosis (group 3). Recanalization rates, procedure times, surgical characteristics, and clinical outcomes were analyzed. RESULTS: Groups 1, 2, and 3 included 33 (38.4%), 17 (19.8%), and 36 (41.9%) patients, respectively. The overall successful recanalization rate was 95.3%, and the good outcome rate was 61.6%. The procedure time in group 1 was shorter than the time in groups 2 and 3 (P < 0.001). The clinical good outcome rate was higher in group 2 than in group 1 (88.2% vs. 54.5%; P = 0.017). Groups 1 and 3 had similar good outcome rates (54.5% vs. 55.6%; P = 0.933). Twenty-seven patients received stent angioplasty: 10 of 17 in group 2 (58.8%) and 17 of 36 in group 3 (47.2%). CONCLUSIONS: The outcome of endovascular treatment for BAO varies among patients with different pathologic mechanisms. Patients with embolism from tandem vertebral artery steno-occlusion achieved the best outcomes. Rescue treatment was more common in patients with embolic BAO with tandem vertebral artery steno-occlusion and BAO with in situ atherosclerotic thrombosis.

The novel Tenzing 7 delivery catheter designed to deliver intermediate catheters to the face of embolus without crossing: clinical performance predicted in anatomically challenging model.

BACKGROUND: In large vessel occlusionstroke, navigation of aspiration catheters (AC) can be impeded by vessel tortuosity and the ophthalmic artery origin. A novel tapered delivery catheter was designed to facilitate delivery without disturbing the embolus. We assessed AC deliverability in vitro and validated the observations in a first-in-human experience. METHODS: In a vascular model with three challenging craniocervical scenarios, two commercial AC were advanced from the carotid to the middle cerebral artery by four neurointerventionalists. Catheter deliverability with standard microwire and microcatheter (MC) combinations and the Tenzing 7 (T7) Delivery Catheter (Route 92 Medical, San Mateo, CA) were compared. Operators rated aspects of catheter deliverability on a 5-point scale. Results were compared with device delivery patterns at a neurovascular center before and after clinical introduction of T7. RESULTS: In vitro, success rate and speed were higher with T7 (96%; mean 30±10 s) than with MC (65%; 72±47 s, p<0.001 each), with fewer interactions with the occlusion site (T7: 54% vs MC: 77%, p=0.004). T7 received superior ratings regarding carotid artery deflection (T7: 2, IQR1-3 vs MC: 3, IQR2-3, p<0.001), guide catheter pushback (T7: 2, IQR1-3 vs MC: 3, IQR3-3, p<0.001) and ophthalmic artery passage (T7: 1.5, IQR1-2 vs MC: 4, IQR3-5, p<0.001). Before introduction of T7 at a single center, delivery of AC to a large vessel occlusion without crossing was achieved in 15/123 cases (12%). With T7, this rate was 28/31 patients (90.3%). CONCLUSION: Compared with microcatheter and microwire combinations, T7 improves aspiration catheter delivery in vitro, minimizing the need to cross the occlusion. Initial clinical experience appears to validate the model's observations.

Quantitative Characterization of Recanalization and Distal Emboli with a Novel Thrombectomy Device.

PURPOSE: The first-pass effect during mechanical thrombectomy improves clinical outcomes regardless of first-line treatment approach, but current success rates for complete clot capture with one attempt are still less than 40%. We hypothesize that the ThrombX retriever (ThrombX Medical Inc.) can better engage challenging clot models during retrieval throughout tortuous vasculature in comparison with a standard stent retriever without increasing distal emboli. MATERIALS AND METHODS: Thrombectomy testing with the new retriever as compared to the Solitaire stent retriever was simulated in a vascular replica with hard and soft clot analogs to create a challenging occlusive burden. Parameters included analysis of distal emboli generated per clot type, along with the degree of recanalization (complete, partial or none) by retrieval device verified by angiography. RESULTS: The ThrombX device exhibited significantly higher rates of first-pass efficacy (90%) during hard clot retrieval in comparison with the control device (20%) (p < 0.009), while use of both techniques during soft clot retrieval resulted in equivalent recanalization. The soft clot model generated higher numbers of large emboli (>200 µm) across both device groups (p = 0.0147), and no significant differences in numbers of distal emboli were noted between the ThrombX and Solitaire techniques. CONCLUSIONS: Irrespective of clot composition, use of the ThrombX retriever demonstrated high rates of complete recanalization at first pass in comparison with a state-of-the-art stent retriever and proved to be superior in the hard clot model. Preliminary data suggest that risk of distal embolization associated with the ThrombX system is comparable to that of the control device.

Symptomatic intracranial embolic foreign-body reactions after endovascular neurointerventional procedures: A retrospective study in a tertiary hospital.

INTRODUCTION: Polymer-coats may peel-off the surface of catheters and devices during endovascular procedures and might lead to brain inflammatory foreign-body reactions. METHODS: We conducted a retrospective, descriptive, single-centre study including all patients with symptomatic intracranial oedematous and contrast-enhancing lesions after any neurointerventional procedure performed in our hospital between 2013 and 2019. RESULTS: From a total of 7446 neurointerventional procedures, 11 cases were identified (9 female, 2 male, median age 47 year-old), with an incidence of 0.14 %. The procedures were therapeutic in all: ten aneurysm embolization/isolation, one acute ischaemic stroke recanalization. Intracranial coils, stent or both were placed in all. Symptoms appeared during the following one day to fourteen months (median of 4.2 weeks). Brain MRI showed oedematous, contrast-enhancing lesions scattered through the vascular territory of the canalized vessel. Brain biopsy confirmed the diagnosis in one case and was supportive in another one. Eight patients received immunosuppression. No treatment was started in two. After a median time of follow-up of 3.5 years, five patients are totally asymptomatic. One patient presents slight weakness. Four patients have remote symptomatic seizures, but they have comorbid lesions (previous stroke, intracranial haemorrhage, biopsy needle-track's gliosis). Follow-up MRI showed significant improvement in all the cases, with complete resolution in five. Non-symptomatic lesion fluctuation was observed in three cases. Two patients experienced symptomatic rebounds. CONCLUSION: Intracranial embolic foreign-body symptomatic reactions are uncommon complications of neurointerventional procedures. Diagnostic angiographies might have lower risk of polymer-embolization than therapeutic procedures. This entity's early recognition enables making proper diagnosis and treatment decisions.

An Early Case of Fat Embolism Syndrome Occurring Following Polytrauma.

Fat embolism syndrome (FES) is a clinical entity occurring due to the presence of fat particles in the microcirculation, typically manifesting 12-72 hours after long bone trauma with respiratory distress, altered mental status, and petechial rash. Our case is that of a 17-year-old girl who suffered multiple orthopedic injuries without intracranial trauma after being a pedestrian struck by a vehicle. Despite presenting with a normal Glasgow Coma Score (GCS), within 4 hours of presentation, she was noted to have an acute mental status change to a GCS 7 with a normal computed tomography brain. Magnetic resonance imaging of the brain was suggestive of FES which, in this patient, had a rapidly progressing course with the development of severe cerebral edema and intracranial hypertension refractory to maximal medical therapy. Our patient required bilateral craniectomies for intracranial decompression and progressed over a 2-month hospital course to have subsequent cranioplasty and functional neurologic improvement. FES requires a high index of clinical suspicion in the presence of long bone fracture with unexplained altered mental status. The clinical course can be rapidly progressing with the development of intracranial hypertension which may benefit from surgical decompression with optimistic prognosis.

Cerebral embolization associated with parenchymal seeding of the left atrial myxoma: Potential role of interleukin-6 and matrix metalloproteinases.

Systemic embolization has been reported in up to 40% of patients with left atrial myxoma, half of them with cerebral involvement. However, development of intracerebral embolization associated with parenchymal seeding of the myxoma emboli is an extremely rare complication, with only 36 histologically diagnosed cases reported in the published literature. We describe a 69-year-old woman who arrived at the emergency service with hemiparesis associated with drug-resistant epilepsy and a medical history of resection of a left atrial myxoma 10 months previously. Cranial computed tomography revealed multiple large lesions of heterogeneous density and cystic components in the occipital lobes and posterior fossa parenchyma. Histopathological analyses after stereotactic biopsy of the occipital lesion revealed infiltrative myxoma cells with benign histological findings and uniform expression of calretinin similar to that of the primary cardiac myxoma. Additional immunohistochemical studies confirmed brain parenchymal seeding of the myxoma cells with strong expression of interleukin-6 (IL-6) and focal expression of matrix metalloproteinases-2 (MMP-2). Here, we discuss the clinicopathological features of intracerebral embolization of left atrial myxomas associated with progressive parenchymal seeding of the tumor emboli and the potential pathogenic role of IL-6 and MMPs.