Einfluss der Lage des aktiven Kontaktes innerhalb des Nucleus subthalamicus auf den Effekt der tiefen Hirnstimulation bei Parkinson Patienten- Eine MRT-basierte Untersuchung

Anhand Prä- und postoperativer MRT-Bilder wird die Lage der Elektroden zur Hochfrequenzstimulation innerhalb des N. subthalamicus bestimmt und mit dem klinischen Ergebnis der Stimulation bei 30 Parkinson Patienten korreliert. Eine Stimulation in lateralen Anteilen des STN bringt signifikant bessere klinische Ergebnisse

White Matter Changes Along the Electrode Lead in Patients Treated With Deep Brain Stimulation

Introduction: Deep brain stimulation (DBS) is an established treatment for various movement disorders. There is little data available about the potential damage to brain parenchyma through DBS treatment. The objective of this study was to investigate the occurrence of signal changes on magnetic resonance imaging (MRI) in patients treated with DBS.Methods: We retrospectively analyzed MRI scans of 30 DBS patients (21 patients with Parkinson's disease, 3 patients with dystonia and 6 patients with tremor) that had undergone additional MRI scans after DBS surgery (ranging from 2 months to 8 years). Axial T2 sequences were analyzed by two raters using a standardized lesion mapping procedure.Results: 26 out of 30 analyzed patients showed hyperintense white matter changes surrounding the DBS lead (mean volume = 2.43 ml). Lesions were prominent along the upper half of the electrode lead within the subcortical white matter, with no abnormalities along the lower lead. Their volume was significantly correlated to the time from surgery to MRI and to the number of microelectrodes used in surgery, but was independent from underlying disease (Parkinson's disease, dystonia, tremor), target structure (STN, GPi, VIM), demographical data, or cardiovascular risk factors.Discussion: White matter changes along the electrode leads in DBS patients are a frequent finding. These changes seem to evolve with certain latency after surgery and might be radiologically classified as a gliosis. Our findings identify the number of intraoperatively used microelectrodes as a risk factor in the formation of gliosis. Therefore, mechanical damage at the time of surgery and an individual tissue response might contribute to their evolution. Further studies are needed to define the exact mechanisms and their clinical impact

Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model

PURPOSE  A direct aspiration first pass technique (ADAPT) is an effective thrombectomy option in patients with acute ischemic stroke. Balloon guide catheters (BGC) seem to improve the efficacy of stent retrievers and ADAPT. The last generation 6F aspiration catheters require 9F BGCs, which are rigid devices that are challenging to position in a tortuous anatomy. In this experimental study the efficacy of 6F ADAPT alone and 5F ADAPT combined with 8F BGC was evaluated. MATERIALS AND METHODS  Either a fibrin rich (white) clot or an RBC rich (red) clot was placed in the M1 segment of a transparent silicon phantom. Physiological hemodynamic conditions were maintained. The clots were retrieved by 6F aspiration catheter via 8F long sheath or 5F aspiration catheter via a flexible 8F BGC. Thrombectomy was performed under direct visual control. The primary endpoints were the number of passes and the number of distal emboli. RESULTS  Ten experiments were made with each clot model and thrombectomy technique (n = 40). Full recanalization could be achieved in every experiment. First pass mTICI 3 could be achieved by 6F ADAPT in 80 % of red clots and 90 % of white clots. Distal emboli were caused in 10 % and 20 %, respectively. When using 5F ADAPT combined with BGC, a first pass mTICI 3 rate of 90 % in red clots and 100 % in white clots could be achieved. A 10 % rate of distal emboli occurred in both groups. In almost all experiments (both techniques), the thrombi clogged the aspiration catheter. No statistically significant differences could be found between the techniques and clot models. CONCLUSION  6F ADAPT without BGC was as effective as 5F ADAPT combined with a flexible 8F BGC, with both techniques showing high first-pass recanalization rates and low distal emboli rates. Especially in the case of a tortuous anatomy, these setups should be considered as alternatives to a rigid 9F BGC. The thrombus compositions seemed to be irrelevant in this setting. KEY POINTS   · 6F ADAPT with no BGC and 5F ADAPT with BGC were very effective and performed equally.. · Both techniques should be considered in tortuous anatomy.. · In this setting the clot composition showed no effect on the recanalization rate.. CITATION FORMAT · Madjidyar J, Nerkada L, Larsen N et al. Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model. Fortschr Röntgenstr 2021; 193: 544 - 550

Multimodal validation of focal enhancement in intracranial aneurysms as a surrogate marker for aneurysm instability

Purpose!#!Circumferential enhancement on MR vessel wall imaging has been proposed as a biomarker of a higher risk of rupture in intracranial aneurysms. Focal enhancement is frequently encountered in unruptured aneurysms, but its implication for risk stratification and patient management remains unclear. This study investigates the association of focal wall enhancement with hemodynamic and morphological risk factors and histologic markers of wall inflammation and degeneration.!##!Methods!#!Patients with an unruptured middle cerebral artery aneurysm who underwent 3D rotational angiography and 3T MR vessel wall imaging showing focal wall enhancement were included. Hemodynamic parameters were calculated based on flow simulations and compared between enhanced regions and the entire aneurysm surface. Morphological parameters were semiautomatically extracted and quantitatively associated with wall enhancement. Histological analysis included detection of vasa vasorum, CD34, and myeloperoxidase staining in a subset of patients.!##!Results!#!Twenty-two aneurysms were analyzed. Enhanced regions were significantly associated with lower AWSS, lower maxOSI, and increased LSA. In multivariate analysis, higher ellipticity index was an independent predictor of wall enhancement. Histologic signs of inflammation and degeneration and higher PHASES score were significantly associated with focal enhancement.!##!Conclusion!#!Focal wall enhancement is colocalized with hemodynamic factors that have been related to a higher rupture risk. It is correlated with morphological factors linked to rupture risk, higher PHASES score, and histologic markers of wall destabilization. The results support the hypothesis that focal enhancement could serve as a surrogate marker for aneurysm instability

sj-docx-1-ine-10.1177_15910199221145985 - Supplemental material for The effect of the size of the new contour neurovascular device for altering intraaneurysmal flow

Supplemental material, sj-docx-1-ine-10.1177_15910199221145985 for The effect of the size of the new contour neurovascular device for altering intraaneurysmal flow by Mariya S Pravdivtseva, Andrey N Pravdivtsev, Sönke Peters, Johannes Hensler, Naomi Larsen, Jan-Bernd Hövener, Olav Jansen and Fritz Wodarg in Interventional Neuroradiology</p

Influence of stent design and use of protection devices on outcome of carotid artery stenting : A pooled analysis of individual patient data

Background and purpose: Carotid artery stenting is an alternative to endarterectomy for the treatment of symptomatic carotid stenosis but was associated with a higher risk of procedural stroke or death in randomized controlled trials (RCTs). Technical aspects of treatment may partly explain these results. The purpose of this analysis was to investigate the influence of technical aspects such as stent design or the use of protection devices, as well as clinical variables, on procedural risk. Methods: We pooled data of 1557 individual patients receiving stent treatment in three large RCTs comparing stenting versus endarterectomy for symptomatic carotid stenosis. The primary outcome event was any procedural stroke or death occurring within 30 days after stenting. Results: Procedural stroke or death occurred significantly more often with the use of open-cell stents (61/595 patients, 10.3%) than with closed-cell stents (58/962 patients, 6.0%; RR 1.76; 95% CI 1.23 to 2.52; P=0.002). Procedural stroke or death occurred in 76/950 patients (8.0%) treated with protection devices (predominantly distal filters) and in 43/607 (7.1%) treated without protection devices (RR 1.10; 95% CI 0.71 to 1.70; P=0.67). Clinical variables predicting the primary outcome event were age, severity of the qualifying event, history of prior stroke, and level of disability at baseline. The effect of stent design remained similar after adjustment for these variables. Conclusions: In symptomatic carotid stenosis, the use of stents with a closed-cell design is independently associated with a lower risk of procedural stroke or death compared with open-cell stents. Filter-type protection devices do not appear to reduce procedural risk

Acute thromboses and occlusions of dual layer carotid stents in endovascular treatment of tandem occlusions

International audiencePurpose To evaluate the occurrence and risk factors of acute in-stent thrombosis or stent occlusion in patients with tandem occlusions receiving intracranial mechanical thrombectomy and emergent extracranial internal carotid artery stenting with a dual layer carotid stent. Methods Multicenter retrospective data collection and analysis of stroke databases of seven comprehensive stroke centers from three European countries. Results Overall, 160 patients (mean (SD) age 66 (12) years; 104 men (65%); median (IQR) baseline NIHSS 14 (9–18); IV lysis, n=97 (60.6%)) were treated for a cervical carotid artery occlusion or stenosis using a CASPER stent (MicroVention), and received mechanical thrombectomy for an intracranial occlusion between April 2014 and November 2018. During the procedure or within 72 hours, formation of thrombus and complete occlusion of the CASPER stent was observed in 33/160 (20.8%) and in 12/160 patients (7.5%), respectively. In 25/33 (75.8%) and in 9/12 patients (75%), respectively, this occurred during the procedure. No statistically significant difference was observed between patients with and without thrombus formation with regard to pre-existing long term medication with anticoagulants or intraprocedural administration of heparin, acetylsalicylic acid (ASA), or heparin and ASA. Favorable early neurological outcome was similar in patients with (n=15; 45.5%) and without (n=63; 49.6%) thrombus formation at the CASPER stent. Conclusion Acute thrombosis or occlusion of CASPER stents in thrombectomy patients receiving emergent extracranial internal carotid artery stenting for tandem occlusions were observed more often during the procedure than within 72 hours of follow-up, were less frequent then previously reported, and showed no impact on early neurological outcome

Influence of stent design and use of protection devices on outcome of carotid artery stenting: a pooled analysis of individual patient data.

BACKGROUND AND PURPOSE: Carotid artery stenting is an alternative to endarterectomy for the treatment of symptomatic carotid stenosis but was associated with a higher risk of procedural stroke or death in randomized controlled trials (RCTs). Technical aspects of treatment may partly explain these results. The purpose of this analysis was to investigate the influence of technical aspects such as stent design or the use of protection devices, as well as clinical variables, on procedural risk. METHODS: We pooled data of 1557 individual patients receiving stent treatment in three large RCTs comparing stenting versus endarterectomy for symptomatic carotid stenosis. The primary outcome event was any procedural stroke or death occurring within 30 days after stenting. RESULTS: Procedural stroke or death occurred significantly more often with the use of open-cell stents (61/595 patients, 10.3%) than with closed-cell stents (58/962 patients, 6.0%; RR 1.76; 95% CI 1.23 to 2.52; P=0.002). Procedural stroke or death occurred in 76/950 patients (8.0%) treated with protection devices (predominantly distal filters) and in 43/607 (7.1%) treated without protection devices (RR 1.10; 95% CI 0.71 to 1.70; P=0.67). Clinical variables predicting the primary outcome event were age, severity of the qualifying event, history of prior stroke, and level of disability at baseline. The effect of stent design remained similar after adjustment for these variables. CONCLUSIONS: In symptomatic carotid stenosis, the use of stents with a closed-cell design is independently associated with a lower risk of procedural stroke or death compared with open-cell stents. Filter-type protection devices do not appear to reduce procedural risk