Mechanical Recanalization Research Articles

Safety of 3-month flushing interval for prevention of occlusion in totally implantable venous access ports: An analysis focused on intraluminal clots.

This study aimed to assess the safety and feasibility of a 3-month flushing interval for totally implantable venous access ports (TIVAPs), particularly regarding intraluminal clot formation. Between May 2017 and September 2018, we established a single-center cohort of 151 patients who were referred for TIVAP removal and categorized them into three flushing-interval groups: A (⩽1 month), B (1-2 months), and C (2-3 months). Odds ratios (OR) with 95% confidence intervals (CI) were computed using logistic regression to determine the risk of intraluminal clot occurrence. To compare clot lengths among the groups, we employed linear regression. Restricted cubic splines were used to model the flushing interval as a continuous variable. Compared to Group A, Groups B and C had adjusted ORs of 0.82 (0.35-1.92) and 0.78 (0.29-2.11) for intraluminal clot risk. Occlusion was rare (1/151; 0.7%) and successfully treated with mechanical recanalization. Adjusted differences in clot length compared to Group A were 0.01 (-0.85 to 0.87) for Group B and -0.23 (-1.21 to 0.76) for Group C. Spline regression analysis showed no significant association between the flushing interval and clot length (p for trend = 0.84). The incidence and burden of intraluminal clots did not increase significantly within the first 3 months. Occlusion was rare, even in the presence of clots, and was successfully treated. Therefore, a 3-month flushing interval appears to be a safe and practical option, aligning with the common recommendation for surveillance intervals in patients with cancer.

Fast diffusion kurtosis imaging for venous stroke caused by cerebral venous thrombosis

Background: Diffusion kurtosis imaging (DKI) has been found to be more precise than diffusion weighted imaging (DWI) for detecting irreversible infarction in acute ischemic stroke. This study aimed to evaluate whether fast DKI has distinctive advantages in detecting venous stroke caused by cerebral venous thrombosis (CVT). Methods: All data from patients diagnosed with venous stroke due to CVT and qualified for mechanical recanalization treatment were collected. Fast DKI and DWI were obtained both before and after revascularization therapy, and lesions were measured. Lesion volumes on T2 weighted imaging (T2WI) were followed up at six months. Results: A total of 11 patients were recruited. Compared to the contralateral brain, ADC values of the lesions in pre-operation increased significantly (1340.12±235.42 vs 919.75±128.98, P < 0.05), while MK decreased (0.59±0.11 vs 0.81±0.12, P < 0.05). And the same changing trend about ADC values (1258.94±185.08 vs 949.81±148.52, P < 0.05) and MK values (0.64±0.12 vs 0.83±0.12, P < 0.05) in post-operation. There was no significant difference in the volume of lesions between DKI and DWI during the same examination period (26.97 vs 29.28, Ppre > 0.05; 13.34 vs 13.14, Ppost > 0.05). However, the lesion volume after revascularization was significantly reduced compared to the first DKI and DWI examinations (26.97 vs 13.34, P < 0.05), and the same as DWI (29.28 vs 13.14, P < 0.05). Volume of T2WI lesions after the 6th month diminished significantly compared with both DKI lesions and DWI lesions before treatment (7.25 vs 26.97, P < 0.05; 7.25 vs 31.19, P < 0.05). Fast DKI had a higher signal to noise ratio (SNR) than traditional DKI and DWI. Conclusion: The MK of the venous stroke lesions decreased significantly in the subacute stage of CVT, suggesting reversible infarction. Fast DKI has more distinctive superiority in the evaluation of venous stroke. Fast DKI approach may hold great promise for patients in clinical setting because of a higher SNR than DWI. But the sample need to be further expanded because of only 11 patients recruited.

Current and Future Roles of Glycoprotein IIb-IIIa Inhibitors in Primary Angioplasty for ST-Segment Elevation Myocardial Infarction.

Acute myocardial infarction still represents the major cause of mortality in high-income countries. Therefore, considerable efforts have been focused on the treatment of myocardial infarctions in the acute and long-term phase, with special attention being paid to reperfusion strategies and adjunctive antithrombotic therapies. In fact, despite the successful mechanical recanalization of the epicardial conduit, a substantial percentage of patients still experience poor myocardial reperfusion or acute/subacute in-stent thrombosis. Due the delayed onset of action of currently available oral antiplatelet therapies, glycoprotein (GP) IIb-IIIa inhibitors could be expected to improve clinical outcomes, especially when administrated in the early phase of the infarction, due to the larger platelet composition of fresh thrombi, the dynamic nature of early thrombi, and the larger amount of viable myocardium existing in the early, as compared to a delayed, phase. Considerable evidence has accumulated regarding the benefits from GP IIb-IIIa inhibitors on mortality, especially among high-risk patients and when administered as an upstream strategy. Therefore, based on currently available data, GP IIb-IIIa inhibitors can be considered when the drug can be administered within the first 3 h of symptom onset and among high-risk patients (e.g., those with advanced Killip class or an anterior myocardial infarction). Even though it is not universally accepted, in our opinion, this strategy should be implemented in a pre-hospital setting (in an ambulance) or as soon as possible when arriving at the hospital (at the Emergency Room or Coronary Care Unit, irrespective of whether they are in spoke or hub hospitals). A new, second-generation GP IIb-IIIa inhibitor (zalunfiban) appears to be highly suitable as a pre-hospital pharmacological facilitation strategy at the time of first medical contact due to its favourable features, including its simple subcutaneous administration, rapid onset of action (15 min), and limited time of action (with a half-life of ~1 h), which is likely to minimize the risk of bleeding. The ongoing CELEBRATE trial, including 2499 STEMI patients, may potentially provide compelling data to support the upstream treatment of STEMI patients undergoing mechanical reperfusion. In fact, although the current therapeutic target of increased rates of timely reperfusion has been achieved, the future goal in myocardial infarction treatment should be to achieve the most rapid reperfusion prior to primary percutaneous coronary intervention, thus further minimizing myocardial damage, or, in some cases, even preventing it completely, and improving survival.

Flow restoration during mechanical thrombectomy for large vessel occlusion is associated with an immediate reduction of systemic blood pressure.

Managing blood pressure in patients with large vessel occlusion affects infarct size and clinical outcomes. We examined how restoring blood flow impacts systemic blood pressure during mechanical thrombectomy. Patients with large vessel occlusion in the anterior circulation undergoing mechanical thrombectomy between June 2016 and January 2018 were screened. We included those treated under local anesthesia or conscious sedation and analyzed standardized anesthesia protocols to assess systolic and diastolic blood pressure levels throughout the procedure. The primary outcome was the change of blood pressure, compared 5 min before versus 5 min after the last recanalization attempt. Successful reperfusion was defined as Thrombolysis in Cerebral Infarction score ⩾ 2b. Of 134 patients, 117 (87%) achieved successful angiographic reperfusion, showing a notable systolic blood pressure drop 5 min after flow restoration (10.2 ± 14.6 vs 3.24 ± 8.65 mm Hg, p = 0.009). Successful angiographic reperfusion was a significant predictor for this decrease in multivariable logistic regression: OR = 1.34 (95% CI: 1.03-1.73, p = 0.0299). Among 66 patients not given circulation-affecting meds, a significant systolic pressure reduction was also observed (155 ± 17 mm Hg to 148 ± 17 mm Hg ; p < 0.001). No diastolic pressure changes were significant. Flow restoration was associated with an immediate reduction of systolic blood pressure values in patients undergoing mechanical recanalization under local anesthesia or conscious sedation. This suggests a complex interplay between endovascular stroke therapy and cardiovascular hemodynamics.

Temporal and Spatial Dynamics of Ischemic Stroke Lesions after Acute Therapy: A Comprehensive Edema Assessment Using Combined 1H- and 23Na-MRI.

Ischemic cerebral stroke initiates a complex cascade of pathophysiological events, involving various forms of molecular shifts and edema. Early intervention is pivotal in minimizing tissue loss and improving clinical outcomes. This study explores the temporal and spatial evolution of tissue sodium concentration (TSC) in acute ischemic lesions after acute therapy using 23Na-MRI in addition to conventional 1H-MRI. Prospectively, from examined 58 patients with acute ischemic stroke with a combined 1H/23Na-MRI within 72 h of symptom onset after receiving acute therapy, 31 patients were included in the evaluation of this study. After co-registration of the 23Na-MRI images to the morphological 1H-MRI images, manual segmentation of the ischemic lesions was performed, and the ADC and TSC measurements were quantified and correlated with the time of onset and lesion volume. The mean TSC in ischemic lesions correlated positively with lesion volume (r = 0.52, p = 0.002) and showed a significant association with the time of stroke onset (r = 0.8, p &lt; 0.001). Patients who were treated only with intravenous rtPA showed homogenous sodium signal intensity in the ischemic lesions, whereas the patients who received mechanical recanalization exhibited distinctive sodium signal intensity patterns with focal significant TSC differences. The integration of 1H- and 23Na-MRI provides a nuanced understanding of temporal and spatial changes due to different types of edema in ischemic stroke lesions following acute treatment. Further exploration of these findings may enhance our understanding of stroke pathophysiology and guide personalized therapeutic interventions.

Research progress and challenges of stem cell therapy for ischemic stroke.

Ischemic stroke is a significant global cause of death and disability. Currently, treatment options for acute ischemic stroke are limited to intravenous thrombolysis and mechanical recanalization. Therefore, novel neuroprotective strategies are imperative. Stem cell transplantation possesses the capabilities of differentiation, proliferation, neuronal replacement, nerve pathway reconstruction, secretion of nerve growth factors, and enhancement of the microenvironment; thus, it is a potential therapeutic approach for ischemic stroke. In addition, the immunomodulatory function of stem cells and the combined treatment of stem cells and exosomes exhibit a favorable protective effect on brain injury and neurological dysfunction following stroke. Meanwhile, the theory of microbiota-gut-brain axis provides us with a novel perspective for comprehending and managing neurological diseases. Lastly, stem cell transplantation has demonstrated promising outcomes not only in treating ischemic stroke but also in dealing with other neurological disorders, such as brain tumors. Furthermore, challenges related to the tissue source, delivery method, immune response, and timing of transplantation still need to be addressed to optimize the treatment.

Green synthesis, chemical characterization, and protective potentials of silver nanoparticles on the development of cerebrovascular diseases in rat cerebral ischemia reperfusion injury

Thrombolysis or mechanical recanalization are two methods that can be used to restore blood flow after an ischemic stroke. However, it is important to note that in certain situations, reperfusion can actually exacerbate the initial damage caused by ischemia, leading to a condition known as “cerebral reperfusion injury.” This injury involves several pathological processes, including the infiltration of leukocytes, activation of platelets and complement, postischemic hyperperfusion, and disruption of the blood–brain barrier. The main objective of research conducted globally is to create a novel therapeutic medication for stroke. In light of the nano revolution, it is imperative to merge nanoscience and medicine. Knowledge acquired from nature has paved the path for the development of biogenic technologies, facilitating the production of cutting-edge nanomaterials. We have recently conducted a study to evaluate the neuroprotective properties of a blend of Mellisa officinalis leaf extract and green-mediated silver nanoparticles on the development of cerebrovascular diseases in rat cerebral ischemia reperfusion injury. The silver nanoparticles were thoroughly examined using UV–Vis, FE-SEM, and EDX analyses to ensure comprehensive characterization. The Ag NPs were observed to have various polymorphic shapes and were found to be aggregated. Also, the particles average size was measured by ImageJ software and it is about 29.15 nm. The UV–Vis measurements showed that the spectra displayed the highest absorption at around 432 nm. The stroke occurred as a result of the occlusion of the middle cerebral artery for 1.5 h, followed by reperfusion for 2 days. Before the ischemia reperfusion, the rats received an intravenous injection of AgNPs at doses of 40, 80 and 160 µg/kg once daily for a consecutive period of 3 days. The evaluation of the cell damage index involved assessing various factors such as immunoglobulin G (IgG) extravasation into the cerebral parenchyma, lactate dehydrogenase efficacy, serum MDA level, infarct volume, and learning and memory function. The results of the study showed that pretreatment with AgNPs had a protective effect on stroke in animals. Moreover, AgNPs effectively alleviated the memory and learning impairments caused by stroke. Additionally, AgNPs significantly reduced infarct volume, IgG extravasation, serum MDA level, and lactate dehydrogenase efficacy.

New Perspectives in Neuroprotection for Ischemic Stroke

The constant failure of new neuroprotective therapies for ischemic stroke has partially halted the search for new therapies in recent years, mainly because of the high investment risk required to develop a new treatment for a complex pathology, such as stroke, with a narrow intervention window and associated comorbidities. However, owing to recent progress in understanding the stroke pathophysiology, improvement in patient care in stroke units, development of new imaging techniques, search for new biomarkers for early diagnosis, and increasingly widespread use of mechanical recanalization therapies, new opportunities have opened for the study of neuroprotection. This review summarizes the main protective agents currently in use, some of which are already in the clinical evaluation phase. It also includes an analysis of how recanalization therapies, new imaging techniques, and biomarkers have improved their efficacy.

Exploring Superselective Intraarterial Thrombolysis for Autologous Fat Injection-Induced Vision Loss.

Intravascular injection represents the most severe complication in fat transplantation procedures. Currently, the prognosis for patients who suffer from blindness due to fat transplantation-induced ocular vascular occlusion is far from optimistic. The aim of this study was to explore and evaluate the efficacy and safety of arterial thrombolysis in the treatment of ocular vascular occlusion caused by fat transplantation. We analyzed the data of 12 patients who underwent intraarterial thrombolysis and conservative treatments for facial autologous fat grafting-associated ocular vascular occlusion. Among the cases, there were 6 instances of ophthalmic artery embolism and 6 cases of central retinal artery occlusion. All patients suffered with sudden blindness, sometimes accompanied by eye pain, ptosis, strabismus, skin necrosis at the injection site, or cerebral microinfarction. They received symptomatic conservative treatments and intraarterial thrombolysis, encompassing mechanical vessel recanalization, vessel dilation, and dissolution of thrombus constituents. Following intraarterial thrombolysis, a noteworthy improvement in the blood flow of both the main trunk and peripheral branches of the ophthalmic artery was observed in the majority of patients when contrasted with their pretreatment status. One patient experienced a headache intraoperatively, while no significant discomfort was reported by the remaining patients. After conservative treatments and intraarterial thrombolysis, all patients experienced improvement in ocular symptoms, skin necrosis, and cerebral infarction. Three patients demonstrated improvement in visual acuity. These patients had surpassed the recommended time window for treatment, yet the occlusion of the ophthalmic artery was not complete. Intraarterial thrombolysis combined with conservative treatments achieves early perfusion and is expected to promote visual recovery. Hospitals that possess the necessary treatment capabilities are encouraged to establish this therapeutic pathway.

The History of Endovascular Stroke Treatment: From Local Intraarterial Fibrinolysis to Stent Retriever Thrombectomy.

Background Acute thromboembolic occlusions of large intracranial arteries are associated with high rates of permanent disability and mortality. Intravenous thrombolysis (IVT) in these patients resulted in an inadequate rate of recanalization and has had limited clinical success. Various endovascular procedures have been attempted to remove intracranial thrombi and reopen occluded vessels. These technical innovations led to the publication of initial case reports, but the methods ultimately did not endure. Endovascular treatment of acute cerebral ischemia was performed only rarely and in selected centers as part of individualized curative attempts. The Solitaire stent was originally developed to treat intracranial aneurysms through stent-assisted coil occlusion. The suggestion that this stent could also be used for intracranial thrombectomy was made as early as 2003 and was clinically confirmed in 2008. Releasing a Solitaire stent into an embolically occluded large cerebral artery, with an incubation time of approximately 3 minutes and slow retraction of the stent, has led to unprecedented success rates of thrombus removal and (sub)total recanalization in more than 90 % of patients. Methods This review article aimed to describe the steps in the development of endovascular stroke therapy, beginning with intra-arterial thrombolysis and early technical innovations leading to the eventual success of stent retriever thrombectomy. Conclusion The potential for mechanical recanalization of acutely occluded large cerebral arteries could not be fully exploited until the advent of stent retriever thrombectomy. The entire concept of stroke treatment fundamentally changed after complete and rapid recanalization first became possible. Randomized controlled trials have shown superiority of stent retriever thrombectomy over IVT. An unparalleled boom in endovascular stroke therapy followed. Key Points:

EPH169 Examination of the Quality of Life of Patients Underwent Ischemic Stroke and Treated With Intravenous Thrombolytic and Mechanical Thrombectomy Recanalization Intervention

EPH169 Examination of the Quality of Life of Patients Underwent Ischemic Stroke and Treated With Intravenous Thrombolytic and Mechanical Thrombectomy Recanalization Intervention

Prior Thrombectomy Does Not Affect the Surgical Complication Rate of Decompressive Hemicraniectomy in Patients with Malignant Ischemic Stroke

BackgroundEven though mechanical recanalization techniques have dramatically improved acute stroke care since the pivotal trials of decompressive hemicraniectomy for malignant courses of ischemic stroke, decompressive hemicraniectomy remains a mainstay of malignant stroke treatment. However, it is still unclear whether prior thrombectomy, which in most cases is associated with application of antiplatelets and/or anticoagulants, affects the surgical complication rate of decompressive hemicraniectomy and whether conclusions derived from prior trials of decompressive hemicraniectomy are still valid in times of modern stroke care.MethodsA total of 103 consecutive patients who received a decompressive hemicraniectomy for malignant middle cerebral artery infarction were evaluated in this retrospective cohort study. Surgical and functional outcomes of patients who had received mechanical recanalization before surgery (thrombectomy group, n = 49) and of patients who had not received mechanical recanalization (medical group, n = 54) were compared.ResultsThe baseline characteristics of the two groups did significantly differ regarding preoperative systemic thrombolysis (63.3% in the thrombectomy group vs. 18.5% in the medical group, p < 0.001), the rate of hemorrhagic transformation (44.9% vs. 24.1%, p = 0.04) and the preoperative Glasgow Coma Score (median of 7 in the thrombectomy group vs. 12 in the medical group, p = 0.04) were similar to those of prior randomized controlled trials of decompressive hemicraniectomy. There was no significant difference in the rates of surgical complications (10.2% in the thrombectomy group vs. 11.1% in the medical group), revision surgery within the first 30 days after surgery (4.1% vs. 5.6%, respectively), and functional outcome (median modified Rankin Score of 4 at 5 and 14 months in both groups) between the two groups.ConclusionsA prior mechanical recanalization with possibly associated systemic thrombolysis does not affect the early surgical complication rate and the functional outcome after decompressive hemicraniectomy for malignant ischemic stroke. Patient characteristics have not changed significantly since the introduction of mechanical recanalization; therefore, the results from former large randomized controlled trials are still valid in the modern era of stroke care.

Solvent Exchange Induced In Situ Formed Hydrogel as Liquid Embolic Agents

AbstractEndovascular embolization can selectively deploy embolic agents into diseased or injured blood vessels to complete the treatment. However, traditional embolic agents still face challenges, such as poor intravascular diffusivity, non‐biodegradable, unstable mechanical properties, radiolucency, and recanalization. Herein, we report a poly (lipoic acid‐tannic acid)/tromethamine/Galinstan (PLTTG) dimethyl sulfoxide (DMSO) solution‐derived hydrogel liquid embolic agent. By injecting PLTTG DMSO solution into body fluids, a PLTTG hydrogel can be formed in situ owing to the solvent exchange induced intra‐ and inter‐polymer hydrogen bonding and electrostatic interactions. Moreover, the gelation time and injection forces of the solution as well as the mechanical properties and embolic pressure of the obtained hydrogels can be adjusted by changing the concentration of PLTTG. The PLTTG hydrogel can effectively embolize the renal artery and femoral vein without recanalization and displacement in rabbit models. Furthermore, the hydrogel can embolize the ruptured femoral artery to arrest active bleeding. Owing to the advantages of the hydrogel, including adjustable gelation time, mechanical properties, viscosities, injection forces, and embolic pressure, as well as good biocompatibility and biodegradability, radiopacity, excellent embolization performance and intravascular diffusivity, easy usage, low cost, allowing it to be a potential embolic agent to treat multiple vascular diseases in clinic.

Intravenous thrombolysis and mechanical recanalization for acute ischemic stroke in deep brain stimulation patients: a case series

BackgroundIntravenous thrombolysis (IVT) and endovascular mechanical thrombectomy therapy (MT) are well established in the treatment of acute ischemic stroke. It is currently unclear whether these treatments can be applied in patients with previous deep brain stimulation (DBS) surgery and how long the interval to the DBS operation should be.MethodsFour patients with ischemic stroke and IVT or MT were included in this retrospective case series. Data on demographics, genesis, severity and course of the stroke and the DBS indication were extracted and evaluated. Furthermore, a literature review was conducted. Outcomes and hemorrhagic complications after IVT, MT or intra-arterial thrombolysis in patients with prior deep brain stimulation surgery and intracranial surgery were analyzed.ResultsFour patients with acute ischaemic stroke and previous DBS surgery were treated with IVT (2 patients), MT (1) or a combined therapy of IVT and MT (1). The time interval to the previous DBS surgery was between 6 and 135 months. In these four patients, no bleeding complications occurred. The literature review revealed four publications with a total of 18 patients, who were treated with IVT, MT or intra-arterial thrombolysis. Of these 18 patients, only 1 had undergone deep brain stimulation surgery, the other 17 patients had received brain surgery for other reasons. Bleeding complications occurred in four of the 18 reported patients, but not in the DBS case. All four patients with bleeding complications were reported to have died as a result. In three of the four patients with fatal outcome, surgery was less than 90 days before the onset of stroke.ConclusionIVT and MT were tolerated by four patients with ischemic stroke more than 6 months after DBS surgery without bleeding complications.

Three-dimensional rotational angiography improves mechanical thrombectomy recanalization rate for acute ischaemic stroke due to middle cerebral artery M2 segment occlusions.

Occlusions of the middle cerebral artery (MCA) M2 segments can be difficult to address with mechanical thrombectomy (MTB) using standard projections and this can affect the final recanalization. Three-dimensional rotational angiography (3D-RA) allows to obtain a 3D model of cerebral vessels in a few seconds and to determine the best two-dimensional (2D) projections to be selected to evaluate and treat cerebrovascular diseases, such as aneurysms or vascular malformations. We aimed to determine if 3D-RA could be applied also in MTB. A retrospective review of two patient cohorts treated during two time periods of 12 months before and after the introduction of 3D-RA use at our institution for MTB in M2 occlusions. Analyses were conducted to compare the two groups for procedural characteristics, such as timing, recanalization rate and complications and clinical outcome. One hundred acute ischaemic stroke (AIS) patients (3D-RA group = 57; controls = 43) underwent MTB for an M2 occlusion during the two study periods. Recanalization rates were significantly higher in cases treated with 3D-RA. The mean 3D technique thrombectomy time was compared to that of non-3D cases (47 vs. 49 min, respectively). Our findings showed that 3D-RA is a useful tool to select specific working projections to AIS patients presenting an M2 occlusion by improving final recanalization compared to standard projections, without increasing the overall procedural time.

An old thrombus may potentially identify patients at higher risk of poor outcome in anterior circulation stroke undergoing thrombectomy.

To investigate thrombus age and its association with clinical and procedural parameters in patients with acute ischemic stroke (AIS) due to anterior circulation occlusions. The thrombi of 107 consecutive AIS patients with occlusions in anterior circulation large-arteries were collected during mechanical recanalization. By hematoxylin-eosin staining analysis, thrombi were classified as fresh (< 3days) or old (≥ 3days) according to the hemosiderin positivity. Old thrombi were further classified as thrombi with focal hemosiderin or diffuse hemosiderin according to their predominant distribution. Neuro-interventional data and clinical outcomes were compared based on thrombus age. We identified fresh thrombi in 29 patients and old thrombi in 78 patients. Compared with patients with fresh thrombi, patients with old thrombi were associated with (i) a longer mechanical recanalization time (p = 0.027), (ii) a higher percentage of fibrin/platelets and leukocytes (all p = 0.02) and a lower percentage of erythrocytes (p = 0.001), and (iii) less favorable clinical outcomes at discharge (p = 0.019) and 90days later (OR = 2.76, 95% CI = 1.09-6.99, p = 0.032). Furthermore, 18 (16.8%) of all patients had focal hemosiderin in old thrombi, which was independently linked to a poor clinical outcome 90days later (adjusted OR = 5.37, 95% CI = 1.14-25.28, p = 0.034). The presence of old thrombi, particularly those with focal hemosiderin, may aid in identifying patients with acute ischemic anterior circulation stroke who are at a higher risk of poor clinical outcome at 3-month follow-up.

An Intermodal Correlation Study among Imaging, Histology, Procedural and Clinical Parameters in Cerebral Thrombi Retrieved from Anterior Circulation Ischemic Stroke Patients.

The precise characterization of cerebral thrombi prior to an interventional procedure can ease the procedure and increase its success. This study investigates how well cerebral thrombi can be characterized by computed tomography (CT), magnetic resonance (MR) and histology, and how parameters obtained by these methods correlate with each other as well as with the interventional procedure and clinical parameters. Cerebral thrombi of 25 patients diagnosed by CT with acute ischemic stroke were acquired by mechanical thrombectomy and, subsequently, scanned by a high spatial-resolution 3D MRI including T1-weighted imaging, apparent diffusion coefficient (ADC), T2 mapping and then finally analyzed by histology. Parameter pairs with Pearson correlation coefficient more than 0.5 were further considered by explaining a possible cause for the correlation and its impact on the difficulty of the interventional procedure and the treatment outcome. Significant correlations were found between the variability of ADC and the duration of the mechanical recanalization, the deviation in average Hounsfield units (HU) and the number of passes with the thrombectomy device, length of the thrombus, its RBC content and many others. This study also demonstrates the clinical potentials of high spatial resolution multiparametric MRI in characterization of thrombi and its use for interventional procedure planning.

Large vessel occlusions requiring repeated mechanical thrombectomy caused by silent myocardial infarction in a young adult

ObjectivesSilent myocardial ischemia, defined as objective evidence of myocardial ischemia without symptoms, is associated with ischemic stroke. Nevertheless, silent myocardial infarction is a rare cause of ischemic stroke, especially in young adults with no medical history. Materials and methodsHerein, we report a young adult patient with acute ischemic stroke treated with repeated mechanical thrombectomy for recurrent large vessel occlusions caused by left ventricular thrombus following a silent myocardial infarction. ResultsA 40-year-old man was transferred by ambulance to our hospital because of a generalized seizure. He was diagnosed with cerebral infarction and left middle cerebral artery occlusion. We performed intravenous thrombolysis and mechanical thrombectomy. Recanalization was achieved and his symptoms gradually improved. However, the day after treatment he developed bilateral cerebellar infarction and basilar artery occlusion. We performed a second mechanical thrombectomy and recanalization was achieved. Transthoracic echocardiography revealed a mobile left ventricular thrombus. Although he had no previous chest symptomatic episodes, cardiac examination confirmed myocardial infarction of unknown onset. He was diagnosed with acute ischemic stroke with large vessel occlusions caused by left ventricular thrombus following a silent myocardial infarction. Anticoagulation therapy reduced the amount of thrombus. At 1-year follow-up, he had not experienced any recurrences or symptoms. ConclusionsSilent myocardial infarction should be considered a cause of ischemic stroke in young adults, even without any vascular risk factors. Recurrent large vessel occlusion may occur in patients with left ventricular thrombus, and repeated mechanical thrombectomy should be considered for treatment.

A clinical case of mechanical recanalization of recurrent cerebral embolism in the hyperacute period of ischemic stroke with hemorrhagic transformation

Currently, there is no single algorithm for the treatment of acute tandem occlusion of the internal carotid artery (ICA) and middle cerebral artery (MCA). The article presents the clinical case of ischemic stroke, which developed 10 days after the first ischemic episode with hemorrhagic transformation. As reperfusion therapy, thrombectomy from the M1 segment of the left MCA and simultaneous stenting of the left ICA were performed. The use of dual antiplatelet therapy at a loading dose in this clinical case was justified by the risk of stent thrombosis, but this increased the risk of recurrent hemorrhagic transformation. Follow-up of the patient for 90 days after this vascular event showed a favorable clinical outcome without hemorrhagic complications. The presented clinical case is extremely rare and shows one of the possible approaches in the management of patients with tandem lesions of the brachiocephalic arteries with a history of intracranial hemorrhagic complications. To develop a unified algorithm for managing acute tandem occlusion in recurrent ischemic strokes, more observations are needed.

Clinical Study of High-Resolution C-Arm CT in Mechanical Recanalization and Stent Implantation for Chronic Cerebral Artery Occlusion.

In recent years, among patients with chronic cerebral artery occlusion, recanalization can be achieved by an endovascular operation. However, complications and restenosis rates remain high. To evaluate the utility of high-resolution C-arm CT (Dyna micro-CT) for stent placement in patients with chronic cerebral artery occlusion. We retrospectively reviewed the clinical data of 27 patients with chronic cerebral artery occlusion who underwent mechanical recanalization and stent implantation. Images were reconstructed using conventional C-arm CT (Dyna CT) and Dyna micro-CT. Whether the stent was fully expanded and image quality was evaluated. Follow-up assessments included clinical and angiographic outcomes and complications. Twenty-two patients successfully underwent stenting (22 stents; 14 cases: Neuroform EZ; eight cases: Enterprise); stenting failed in five patients. Compared to Dyna CT, Dyna micro-CT afforded improved visualization of the stent structure, providing significantly improved image quality (P < 0.05). In seven patients, the stent under-expanded and dilatation was performed; thereafter, stent malapposition improved. One patient experienced sudden headache 22 hours after the procedure; CT showed intraparenchymal hemorrhage. The remaining 21 patients did not have acute thrombosis or bleeding complications and were followed up by imaging for 3-6 months. In three patients, digital subtraction angiography showed mild in-stent stenosis. High-resolution C-arm CT can improve visualization of stent structures in chronic cerebral artery occlusion, making it easy to determine the extent of stent deployment and potentially reduce complications and stent restenosis.