Publications by authors named "Tim W Malisch"

At the time of this writing, the coronavirus disease 2019 pandemic continues to be a global threat, disrupting usual processes, and protocols for delivering health care around the globe. There have been significant regional and national differences in the scope and timing of these disruptions. Many hospitals were forced to temporarily halt elective neurointerventional procedures with the first wave of the pandemic in the spring of 2020, in order to prioritize allocation of resources for acutely ill patients and also to minimize coronavirus disease 2019 transmission risks to non-acute patients, their families, and health care workers.

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Background and Purpose- Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry.

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Background: Limited post-marketing data exist on the use of the Solitaire FR device in clinical practice. The North American Solitaire Stent Retriever Acute Stroke (NASA) registry aimed to assess the real world performance of the Solitaire FR device in contrast with the results from the SWIFT (Solitaire with the Intention for Thrombectomy) and TREVO 2 (Trevo versus Merci retrievers for thrombectomy revascularization of large vessel occlusions in acute ischemic stroke) trials.

Methods: The investigator initiated NASA registry recruited North American sites to submit retrospective angiographic and clinical outcome data on consecutive acute ischemic stroke (AIS) patients treated with the Solitaire FR between March 2012 and February 2013.

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Background: Various techniques are used to enhance the results of mechanical thrombectomy with stent-retrievers, including proximal arrest with balloon guide catheter (BGC), conventional large bore proximal catheter (CGC), or in combination with local aspiration through a large-bore catheter positioned at the clot interface (Aspiration-Retriever Technique for Stroke [ARTS]). We evaluated the impact of ARTS in the North American Solitaire Acute Stroke (NASA) registry.

Summary: Data on the use of the aspiration technique were available for 285 anterior circulation patients, of which 29 underwent ARTS technique, 131 CGC, and 125 BGC.

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Background And Purpose: In acute ischemic stroke, fast and complete recanalization of the occluded vessel is associated with improved outcomes. We describe a novel measure for newer generation devices: the first pass effect (FPE). FPE is defined as achieving a complete recanalization with a single thrombectomy device pass.

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Background: The Interventional Management of Stroke III (IMS-III) trial demonstrated no benefit for intravenous recombinant tissue plasminogen activator (IV rt-PA) followed by endovascular therapy versus IV rt-PA alone. However, IMS-III mostly included earlier generation devices. The recent thrombectomy trials have incorporated the stent-retriever technology, but their generalizability remains unknown.

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Background And Purpose: Failure to recanalize predicts mortality in acute ischemic stroke. In the North American Solitaire Acute Stroke registry, we investigated parameters associated with mortality in successfully recanalized patients.

Methods: Logistic regression was used to evaluate baseline characteristics and recanalization parameters for association with 90-day mortality.

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Background: Mechanical thrombectomy with stent-retrievers results in higher recanalization rates compared with previous devices. Despite successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) score ≥2b) of 70-83%, good outcomes by 90-day modified Rankin Scale (mRS) score ≤2 are achieved in only 40-55% of patients. We evaluated predictors of poor outcomes (mRS >2) despite successful recanalization (TICI ≥2b) in the North American Solitaire Stent Retriever Acute Stroke (NASA) registry.

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Background And Purpose: The Solitaire With the Intention for Thrombectomy (SWIFT) and thrombectomy revascularization of large vessel occlusions in acute ischemic stroke (TREVO 2) trial results demonstrated improved recanalization rates with mechanical thrombectomy; however, outcomes in the elderly population remain poorly understood. Here, we report the effect of age on clinical and angiographic outcome within the North American Solitaire-FR Stent-Retriever Acute Stroke (NASA) Registry.

Methods: The NASA Registry recruited sites to submit data on consecutive patients treated with Solitaire-FR.

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Background: Limited post-marketing data exist on the use of the Solitaire FR device in clinical practice. The North American Solitaire Stent Retriever Acute Stroke (NASA) registry aimed to assess the real world performance of the Solitaire FR device in contrast with the results from the SWIFT (Solitaire with the Intention for Thrombectomy) and TREVO 2 (Trevo versus Merci retrievers for thrombectomy revascularization of large vessel occlusions in acute ischemic stroke) trials.

Methods: The investigator initiated NASA registry recruited North American sites to submit retrospective angiographic and clinical outcome data on consecutive acute ischemic stroke (AIS) patients treated with the Solitaire FR between March 2012 and February 2013.

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Background: Endovascular therapy is increasingly used after the administration of intravenous tissue plasminogen activator (t-PA) for patients with moderate-to-severe acute ischemic stroke, but whether a combined approach is more effective than intravenous t-PA alone is uncertain.

Methods: We randomly assigned eligible patients who had received intravenous t-PA within 3 hours after symptom onset to receive additional endovascular therapy or intravenous t-PA alone, in a 2:1 ratio. The primary outcome measure was a modified Rankin scale score of 2 or less (indicating functional independence) at 90 days (scores range from 0 to 6, with higher scores indicating greater disability).

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Background And Purpose: The durability of aneurysm coil embolization is thought to depend on packing density. The expansile property of hydrogel coating on coils increases volumetric packing per coil length. We describe our experience using hydrogel-coated coils (HydroCoils) compared with inert platinum coils in intracranial aneurysm embolization.

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Background: Direct carotid cavernous fistulae (CCF) are commonly treated by endovascular deployment of a detachable balloon into the cavernous sinus to reconstruct the sidewall of the carotid artery and preserve flow in that vessel. Relatively few reports exist describing revisions using constructive, transarterial approaches when this technique fails.

Methods: We describe a novel method using expandable hydrogel-coated platinum coils to revise a failed balloon reconstruction in which the balloon had migrated within the cavernous sinus away from the rent in the carotid wall.

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Background And Purpose: Symptomatic vertebrobasilar disease (VBD) carries a high risk of recurrent stroke. We sought to determine whether a management algorithm consisting of quantitative hemodynamic assessment could stratify stroke risk and guide the need for intervention.

Methods: All patients with symptomatic VBD at our institution are evaluated by a standard protocol including quantitative magnetic resonance angiography (QMRA).

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Purpose: To present the physics data supporting the validity of the clinical dose data from the RAD-IR study and to document the performance of dosimetry-components of these systems over time.

Materials And Methods: Sites at seven academic medical centers in the United States prospectively contributed data for each of 12 fluoroscopic units. All units were compatible with International Electrotechnical Commission (IEC) standard 60601-2-43.

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Purpose: To determine peak skin dose (PSD), a measure of the likelihood of radiation-induced skin effects, for a variety of common interventional radiology and interventional neuroradiology procedures, and to identify procedures associated with a PSD greater than 2 Gy.

Materials And Methods: An observational study was conducted at seven academic medical centers in the United States. Sites prospectively contributed demographic and radiation dose data for subjects undergoing 21 specific procedures in a fluoroscopic suite equipped with built-in dosimetry capability.

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Purpose: To determine patient radiation doses for interventional radiology and neuroradiology procedures, to identify procedures associated with higher radiation doses, and to determine the effects of various parameters on patient doses.

Materials And Methods: A prospective observational study was performed at seven academic medical centers. Each site contributed demographic and radiation dose data for subjects undergoing specific procedures in fluoroscopic suites equipped with built-in cumulative dose (CD) and dose-area-product (DAP) measurement capability compliant with International Electrotechnical Commission standard 60601-2-43.

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