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Medtronic is submitting this report to comply with fda reporting regulations under 21 cfr parts 4 and 803.This report is based upon information obtained by medtronic, which the company may not have been able to fully investigate or verify prior to the date the report was required by the fda.Medtronic has made reasonable efforts to obtain more complete information and has provided as much relevant information as is available to the company as of the submission date of this report.This report does not constitute an admission or a conclusion by fda, medtronic, or its employees that the device, medtronic, or its employee caused or contributed to the event described in the report.In particular, this report does not constitute an admission by anyone that the product described in this report has any ¿defects¿ or has ¿malfunctioned¿.These words are included in the fda 3500a form and are fixed items for selection created by the fda to categorize the type of event solely for the purpose of regulatory reporting.Medtronic objects to the use of these words and others like them because of the lack of definition and the connotations implied by these terms.This statement should be included with any information or report disclosed to the public under the freedom of information act.
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Ann mansur, alex kostynskyy, timo krings, ronit agid, ivan radovanovic, and vitor mendes pereira; journal of neurosurgery; 2021; 135:1598¿1607; the safety profile and angioarchitectural changes after acute targeted embolization of ruptured arteriovenous malformations; doi: 10.3171/2020.9.Jns201558.Medtronic received information in literature article that patients treated with onyx embolization had complications including death. the aim of this study was to 1) compare the safety and efficacy of acute targeted embolization of angiographic weak points in ruptured brain arteriovenous malformations (bavms) versus delayed treatment, and 2) explore the angioarchitectural changes that follow this intervention. the authors conducted a retrospective analysis of a prospectively acquired database of ruptured bavms.Three hundred sixteen patients with ruptured bavms who presented to the hospital within 48 hours of ictus were included in the analysis.The first analysis compared clinical and functional outcomes of acutely embolized patients to those with delayed management paradigms.The second analysis compared these outcomes of patients with acute embolization to those with angio graphic targets who did not undergo acute embolization.Finally, a subset of 20 patients with immediate postembolization angiograms and follow-up angiograms within 6 weeks of treatment were studied to determine the angioarchitectural changes after acute targeted embolization. a total of 316 (75.4%) of 419 patients were included.Seventy-seven patients were excluded because they had incomplete clinical information, 9 patients were under the age of 18 years, 10 were transferred to our center after 48 hours of ictus, and 7 underwent acute surgery for evacuation of hematoma prior to initial imaging assessment.Procedure: the initial digital subtraction angiogram is performed with a diagnostic intention but with a potential conversion to embolization if a rupture point is identified.They defined rupture point as an imaging correspondent to an aneurysm, false aneurysm, or venous pouch related to the hemorrhagic distribution.We often combine digital subtraction angiography (dsa) and other imaging modalities to characterize a certain lesion as the cause of bleeding.While the diagnostic dsa is performed under conscious sedation, the embolization is performed under general anesthesia.The aim of these acute treatments is often to target 1) the ruptured point and/or 2) high-risk angiographic features,10,13¿15 or 3) to occasionally treat the avm at this stage if it has a single or few arterial feeders with good visualization of the draining veins and it is deemed safe to do so.The procedure starts with an avm exploration using microcatheters: magic 1.2 or marathon 1.2 guided with an 0.008-inch hybrid microwire.Selective digital subtraction angiograms are performed in different avm arterial pedicles to identify the compartments and the feeding branches to the rupture point.Once the avm anatomy is defined, the embolization procedure takes place using n-butyl cyanoacrylate (nbca; 30%¿50%) depending on the avm and pedicle flows, dimethyl sulfoxide¿based polymer onyx, or targeted coils of culprit prenidal aneurysms.After this procedure, the patient will be discussed in our multidisciplinary conference to define the definitive treatment 3 months after the initial hemorrhagic presentation.Twenty-eight patients who underwent acute embolization had various concentrations of nbca + lipiodol, 3 patients had onyx, and 1 patient had endovascular coils for a prenidal aneurysm.Half of the patients had embolization of supratentorial avms (7 frontal/parietal, 3 occipital, 5 temporal, and 1 basal ganglia/thalamus) and the other half were infratentorial, mostly cerebellar twenty-five avms, however, did have some deep venous drainage.Thirteen patients (40.6%) had a single arterial feeder, whereas the rest had 2 or more pedicles that were explored.Of the 32 acutely embolized patients, a goal for complete occlusion was set for 10 patients because the avms were more superficial, of a small size, and had a single arterial feeder with easily penetrable venous efferents.Results: there were three deaths (0.9%) and an overall rerupture rate of 4.8% per year.There was no statistical difference in demographic variables, mortality, and rerupture rate between patients with acute embolization and those with delayed management.Patients with acute embolization were more likely to present functionally worse (46.9% vs 69.8%, modified rankin scale score 0¿2, p = 0.018) and to require an adjuvant therapy (71.9% vs 26.4%, p 0.001).When comparing acutely embolized patients to those nonacutely embolized angiographic targets, there was a significant protective effect of acute targeted therapy on rerupture rate (annual risk 1.2% vs 4.3%, p = 0.025) and no difference in treatment complications. obliteration of the angiographic target occurred in 90% of cases on immediate postembolization dsa.Complete avm obliteration was planned for 10 patients, which was successful in 6 patients.While most patients experienced resolution of their angiographic target (which is expected), 5 patients (25.0%) had other angioarchitectural changes noted on delayed dsa.For example, of those with complete immediate avm occlusion, 2 (33.3%) had spontaneous recurrence of their bavms, 1 in the vermian region and the other in the left temporal region.Of the remaining 14 patients with evidence of partial occlusion of their avms, 3 (21.4%) suffered eventual occlusion of their bavms on follow-up dsa.Eleven patients with partially obliterated bavms had a residual on dsa follow-up with no evidence of change in venous drainage pattern, avm size, or spetzler-martin grade.
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