[Orbital trauma]. / Traumata der Orbita.

Orbital trauma can occur independently or in conjunction with other craniofacial trauma and can cause damage to bony and neurovascular structures as well as soft tissues. Appropriate interdisciplinary treatment of patients is essential to prevent long-term damage such as blindness or muscle dysfunction. Even complex fractures and soft tissue damage can be visualized using modern thin-layer computed tomography (CT), which is necessary for proper treatment.

Transorbital sonography and MRI reliability to assess optic nerve sheath diameter in idiopathic intracranial hypertension.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the performance of magnetic resonance imaging (MRI) in measuring the optic nerve sheath diameter (ONSD) compared to the established method transorbital sonography (TOS) in patients with idiopathic intracranial hypertension (IIH). METHODS: Twenty-three patients with IIH were prospectively included applying IIH diagnostic criteria. All patients received a lumbar puncture with assessment of the cerebrospinal fluid (CSF) opening pressure to assure the IIH diagnosis. Measurement of ONSD was performed 3 mm posterior to inner sclera surface in B-TOS by an expert examiner, while three independent neuroradiologists took measurements in axial T-weighted MRI examinations. The sella turcica with the pituitary gland (and potential presence of an empty sella) and the trigeminal cavity were also assessed on sagittal and transversal T1-weighted MRI images by one independent neuroradiologist. RESULTS: The means of ONSD between ultrasound and MRI measurements were 6.3 mm (standard deviation [SD] = 0.6 mm) and 6.2 mm (SD = 0.8 mm). The interrater reliability between three neuroradiologists showed a high interclass correlation coefficient (ICC) (confidence interval: .573 < ICC < .8; p < .001). In patients with an empty sella, the ONSD evaluated by MRI was 6.6 mm, while measuring 6.1 mm in patients without empty sella. No correlation between CSF opening pressure and ONSD was found. CONCLUSIONS: MRI can reliably measure ONSD and yields similar results compared to TOS in patients with IIH. Moreover, patients with empty sella showed significantly larger ONSD than patients without empty sella.

Recurrent reversible in-stent-stenosis after flow diverter treatment.

Flow diverter stents (FDS) are well established in the treatment of intracranial aneurysms which are difficult to treat with conventional endovascular techniques. However, they carry a relatively high risk of specific complications compared to conventional stents. A minor but frequent finding is the occurrence of reversible in-stent-stenosis (ISS) that tend to resolve spontaneously over time. Here, we report the case of a patient in their 30s who was treated with FDS for bilateral paraophthalmic internal carotid artery (ICA) aneurysms. ISS were found at the respective early follow-up examinations on both sides and had resolved at the 1-year follow-up examinations. Surprisingly ISS reoccurred at both sides in later follow-up examinations and again resolved spontaneously. The recurrence of ISS after resolution is a finding that has not been described previously. Its incidence and further development should be investigated systematically. This might contribute to our understanding of the mechanisms underlying the effect of FDS.

Endovascular Treatment Strategies for Aneurysms of the Origin of the Posterior Inferior Cerebellar Artery.

BACKGROUND: Treatment of aneurysms at the origin of the posterior inferior cerebellar artery (PICA) is challenging. Surgery is difficult due to the deep location and proximity to cranial nerves and endovascular treatment is complicated due to the often tortuous anatomy of the PICA and its small diameter. The purpose of this study is to report our experience with the endovascular treatment of aneurysms at the origin of the PICA. METHODS: Consecutive patients with aneurysms at the origin of the PICA who were endovascularly treated at our department were identified from our registry of neuro-angiographies. Clinical, angiographic, and treatment data were analyzed. Endpoints included successful occlusion and recurrence. RESULTS: Twenty-nine patients were included. 79.3% of the aneurysms were wide-neck with a dome-to-neck ratio <2.65.5% of all endovascular procedures were performed by coiling alone. The procedural rupture rate was 18.75% for endovascularly treated aneurysms presenting with subarachnoid hemorrhage (SAH). Successful embolization was achieved non-significantly more often in the coiling-only group (94.7% vs. 70%, P = 0.066). Aneurysm recurrence after successful occlusion was observed in one case. CONCLUSIONS: Though aneurysm and parent vessel characteristics were challenging successful occlusion was achieved in a high rate of treatments, often with standalone coiling. Adjunctive techniques like retrograde stenting seem promising to further enhance endovascular results. Interestingly aneurysms arising solely from the origin of the PICA without the V4-segment involved presented with SAH significantly more often and wide-neck aneurysms presenting with SAH had a significantly higher periinterventional rupture rate.

Endovascular treatment of unruptured intracranial aneurysms with flow diverters: A retrospective long-term single center analysis.

PURPOSE: The introduction of flow diverters (FDs) in 2007 greatly enhanced the treatment of intracranial aneurysms. Here, we present our long-term clinical experience in treating unruptured intracranial aneurysms with FDs. METHODS: 107 patients with unruptured aneurysms and treated with an FD between 2010 and 2019 were retrospectively reviewed. Aneurysm occlusion, procedural complications, and clinical outcome were evaluated. RESULTS: Angiographic follow-up was available for 93 patients with a mean long-term follow-up time of 28.4 ± 21.6 months. Additional coiling was performed in 15.1% of patients (n = 14). Adequate aneurysm occlusion (Kamran grades 3 and 4) at long-term follow-up was achieved in 94.6% of patients (n = 88). 3.2% (n = 3) required endovascular retreatment since the last follow-up showed a lack of aneurysm occlusion (Kamran grade 0) due to a foreshortening of the FD. Incomplete opening of the FD and parent vessel occlusion was seen in 1.1% (n = 1) and 3.2% (n = 3) of patients, respectively. In-stent stenosis was observed in 57% (n = 53) of cases at short-term follow-up and 22.6% (n = 21) at long-term, which were moderate and asymptomatic overall. In-stent stenosis decreased significantly between short- and long-term follow-ups (31.4 ± 17.0% vs 9.7 ± 13.6%, respectively; p ≤ 0.001). Thromboembolic and hemorrhagic events occurred in 7.5% (n = 7) and 1.1% (n = 1) of patients, respectively. Good clinical outcome (modified Rankin scale: 0-2) was obtained in 97.8% (n = 91) leading to an overall treatment-related morbidity of 2.2% (n = 2). There was no procedural mortality. CONCLUSION: Our study shows that FD treatment of unruptured intracranial aneurysms is effective and safe with high occlusion rates and low rates of permanent morbidity at long-term follow-up.

Treatment of Wide-Necked Cerebral Aneurysms Using the WEB Device Including Flow Alteration Assessment With Color-Coded Imaging: A Single Center Experience.

Objective: The Woven EndoBridge (WEB) device (MicroVention, Tustin, CA) has extended the treatment of cerebral aneurysms. Despite the fact that the WEB device has shown promising clinical results, little is known about the caused intra-aneurysmal flow alterations. Here we present our clinical experience with the WEB, including examining various syngo iFlow (Siemens AG, Erlangen, Germany) parameters to predict aneurysm occlusion. Methods: We reviewed the data from patients with unruptured cerebral aneurysms treated with a WEB device between 2016 and 2020. Aneurysm occlusion and complications were assessed. Furthermore, different quantitative criteria were evaluated using syngo iFlow after digital subtraction angiography. Results: A total of 26 patients hosting 26 cerebral aneurysms met the inclusion criteria. Follow-up was available for 21 patients, with a mean of 7.3 ± 6.3 months. A total of 71.4% (n = 15) of the aneurysms included were located in the anterior and 28.6% (n = 6) in the posterior circulation. Adequate aneurysm occlusion was achieved in 85.7% (n = 18). The iFlow parameters for reduced aneurysm outflow (ID-R) differed significantly from the parameters for reduced inflow (PI-R and PI-D) (P < 0.001). The parameters did not differ significantly between adequately and insufficiently occluded aneurysms. Only a trend towards a lower ID-R of insufficiently occluded aneurysms was observed (P = 0.063), indicating a potential predictive value for insufficient aneurysmal outflow. There was no treatment-related morbidity or mortality. Conclusions: The applied syngo iFlow parameters confirmed that flow changes induced by the WEB device significantly affect outflow compared to inflow and have potential predictive value for adequate aneurysm occlusion.

[New MRI guidelines for multiple sclerosis]. / Neue MRT-Leitlinien bei multipler Sklerose.

BACKGROUND: To improve the efficient use of magnetic resonance imaging (MRI) in routine clinical practice, an expert panel has revised the guidelines for its use in the diagnosis and monitoring of multiple sclerosis (MS). OBJECTIVES: The revised guidelines now take into account new developments and relevant advances in knowledge, such as the ongoing debate about safety related to intravenous gadolinium-based contrast agents. The value of spinal cord MRI for diagnostic, prognostic, and surveillance purposes has been re-evaluated. Standardization of brain and spinal cord MRI protocols for diagnosis, assessment of prognosis, and monitoring of therapy, as well as the use of 3D-FLAIR (three-dimensional fluid-attenuated inversion recovery) as the most important sequence in the diagnosis of lesions in the brain have been included, as this allows better interpretation and comparability, e.g., in follow-up assessments.

Treatment of experimental aneurysms with a GPX embolic agent prototype: preliminary angiographic and histological results.

BACKGROUND: Recently, liquid embolic agents have emerged for the endovascular treatment of cerebral aneurysms. Here we describe the in vivo performance of a novel liquid embolization agent (GPX Embolic Device). METHODS: Elastase-induced aneurysms were embolized with a GPX prototype under balloon assistance. Digital subtraction angiography was performed pre-deployment and immediately after, and at 5, 10, and 30 min post-deployment in 10 rabbits and at 1 month in 8 rabbits. The early post-deployment intra-aneurysmal flow was graded as unchanged, moderately diminished, or completely absent. At 1 month the status of aneurysm occlusion was evaluated. Adhesion to catheter material and migration of GPX was assessed. RESULTS: The mean aneurysm neck diameter, width, and height were 3.6±1.0 mm, 3.0±0.8 mm, and 7.4±1.4 mm, respectively. The mean dome-to-neck ratio was 0.9±0.2. Complete stagnation of intra-aneurysmal flow was observed in 9 of 10 aneurysms (90%) within 30 min of device deployment. One aneurysm showed moderately diminished intra-aneurysmal flow at 30 min. At 1 month, 8 aneurysms were completely occluded. There was no evidence of GPX adhesion to the catheter material. Histologically, a leukocyte and foreign body reaction to GPX was detectable 28 days after embolization. CONCLUSIONS: This is the first preclinical study reporting the performance of a protype version of the GPX Embolic Device in a wide-neck aneurysm model. GPX showed promising results by achieving and maintaining high rates of complete angiographic occlusion, but may induce an inflammatory reaction.

Case report: cerebral sinus vein thrombosis in two patients with AstraZeneca SARS-CoV-2 vaccination.

SARS-CoV-2 infection is associated with an increased rate of thromboembolic events and mortality. Different vaccines are globally used to limit the pandemic. In this report, we present the case of two young female patients with newly diagnosed cerebral sinus vein thrombosis occurring after injection of the vector-based ChAdOx1 vaccine. Both patients presented with unusual headache only. The two of them used an estrogen-containing contraception, had had a history of deep venous thrombosis, and both had MTHFR mutations. Both patients developed SARS-CoV-2 specific humoral and cellular immunity including both CD4 and CD8 T cells. This rare, but serious complication needs to be considered after vaccination of young females, even if there is no evidence of heparin-induced thrombocytopenia.

Retrospective analysis of intracranial aneurysms after flow diverter treatment including color-coded imaging (syngo iFlow) as a predictor of aneurysm occlusion.

PURPOSE: Flow Diverters (FD) have immensely extended the treatment of cerebral aneurysms in the past years. Complete aneurysm occlusion is a process that often takes a certain amount of time and is usually difficult to predict. Our aim was to investigate different syngo iFlow parameters in order to predict aneurysm occlusion. METHODS: Between 2014 and 2018 patients with unruptured cerebral aneurysms treated with a FD were reviewed. Aneurysm occlusion and complication rates have been assessed.In addition, various quantitative criteria were assessed using syngo iFlow before, after the intervention, and after short and long-term digital subtraction angiography (DSA). RESULTS: A total of 66 patients hosting 66 cerebral aneurysms were included in this study. 87.9% (n = 58) aneurysms in the anterior and 12.1% (n = 8) in the posterior circulation were treated. Adequate aneurysm occlusion at long-term follow-up (19.05 ± 15.1 months) was achieved in 90.9% (n = 60). Adequately occluded aneurysm revealed a significantly greater peak intensity delay (PI-D, p = 0.008) and intensity decrease ratio (ID-R, p < 0.001) compared to insufficiently occluded aneurysms. Increased intra-aneurysmal contrast agent intensity (>100%) after FD implantation resulted in an ID-R < 1, which was associated with aneurysm growth during follow-up DSA. Retreatment with another FD due to foreshortening and/or aneurysm growth was performed in 10.6% (n = 7). Overall morbidity and mortality rates were 1.5% (n = 1) and 0%. CONCLUSION: The applied syngo iFlow parameters were found to be useful in predicting adequate aneurysm occlusion and foresee aneurysm growth, which might indicate the implantation of another FD.

[Nonneoplastic lesions of the spinal canal]. / Nichtneoplastische Raumforderungen des Spinalkanals.

Numerous vascular, inflammatory, degenerative and tumorous lesions of the spinal canal can cause paraplegic symptoms. In addition to the neurological examination and the leading symptoms, the first topographical classification of the (suspected) disease is essential for further diagnostics. Hence, high-resolution magnet resonance imaging (MRI) is the gold standard for the majority of questions. To avoid diagnostic and therapeutic mistakes, differentiation of intraspinal tumors from tumor-like (nonneoplastic) lesions is indispensable, which is often only possible after follow-up imaging or surgical exploration.

Solitaire Stentectomy Using a Stent-Retriever Technique in a Porcine Model.

PURPOSE: Mechanical thrombectomy using the Solitaire device has become a standard treatment of ischemic stroke due to large vessel occlusions. Inadvertent detachment is a feared complication, which is associated with poor clinical outcome. The aim of this experimental study was to assess in a porcine model the feasibility and effectiveness of rescuing detached Solitaire devices using different stent retrievers. METHODS: Solitaire FR devices (4â€¯× 15/20 mm and 6â€¯× 20/30 mm) were placed in the axillary artery of pigs. By means of 3 different stent retrievers (Trevo ProVue; EmboTrap II revascularization device; 3D revascularization device) a total of 24 rescue maneuvers (8 per retriever) were performed by deploying the retrievers within the deployed Solitaire devices and trapping parts of the Solitaire within the microcatheter. Rescue rates, rescue time and complications were assessed. RESULTS: Overall stentectomy of the Solitaire devices was successful in all cases (100%). Time of rescue was comparable using the applied stent retrievers (Trevo ProVue; EmboTrap II revascularization device; 3D revascularization device). Complications, such as entrapment of the Solitaire-retriever complex at the intermediate catheter, Solitaire migration, vasospasm, perforation, or dissection were not observed. CONCLUSION: Stentectomy of inadvertently detached Solitaire devices using different stent retrievers is a feasible and effective method. Rescue rates and times with the Trevo ProVue, EmboTrap II and 3D revascularization device were comparable.

Single Center Experience in Stent-Assisted Coiling of Complex Intracranial Aneurysms Using Low-Profile Stents : The ACCLINO® Stent Versus the ACCLINO® Flex Stent.

PURPOSE: The introduction of low-profile stent systems has broadened and facilitated the treatment of complex intracranial aneurysms. This retrospective case series study was conducted to assess and compare the clinical and angiographic outcomes of patients with complex intracranial aneurysms who were treated with ACCLINO® (AS) and ACCLINO® flex stents (AFS). METHODS: In 85 patients (female 61; male 24) a total of 95 complex intracranial aneurysms, 71 (74.7%) in the anterior circulation and 24 (25.3%) in the posterior circulation were treated. Angiographic and clinical data, aneurysm characteristics and follow-up results were analyzed. RESULTS: The AS was used in 47 cases (49.5%) and the AFS in 48 cases (50.5%). Initial angiography after the intervention showed a complete occlusion in 52.6% (Raymond-Roy occlusion classification [RROC] 1), a neck remnant in 38.9% (RROC 2) and an incomplete occlusion in 8.4% (RROC 3). Follow-up (AS: 25.2 ± 15.4 months; AFS: 9.6 ± 8.0 months) revealed an occlusion rate of 70.5% (RROC 1), 27.4% (RROC 2) and 2.1% (RROC 3). There was no statistically significant difference between the initial (p = 0.484) and the follow-up occlusion rate (p = 0.284) when comparing the two devices. Recoiling was performed in 8 cases (8.4%). The overall complication rate was 9.5% with 5 strokes (5.3%), 2 hemorrhages (2.1%), 1 in-stent stenosis (1.1%), 1 stent occlusion (1.1%) and 2 stent thromboses (2.1%). There was no procedure-related mortality. CONCLUSION: Using the ACCLINO® and ACCLINO® flex stent system is a feasible and effective procedure with an acceptable safety profile. Initial and follow-up angiographic results were satisfactory.

Different Rescue Approaches of Migrated Woven Endobridge (WEB) Devices: an Animal Study.

PURPOSE: Treatment of wide-necked intracranial aneurysms using the Woven Endobridge (WEB) device has become broadly accepted. Feared complications with the potential of increased poor clinical outcome include dislocations and migration of the device. This study was carried out to determine the effectiveness of a variety of different strategies to rescue migrated WEB devices. METHODS: In a porcine model, WEB devices of different sizes (SL [single layer] 3.5â€¯× 2mm and SL 4.0â€¯× 3 mm, SL 8â€¯× 5 mm and SLS 8 mm [single layer spherical]) were placed into both the subclavian and axillary arteries. A total of 32 rescue maneuvers (8 per rescue device) were performed. Small WEBs were rescued using reperfusion catheters (RC) (SOFIA Plus and JET 7), larger WEBs were rescued using dedicated rescue devices (Microsnare and Alligator). Rescue rates, times, attempts and complications were assessed. RESULTS: Rescue attempts of migrated WEBs were successful in all cases (100%). Rescue time (p = 0.421) and attempts (p = 0.619) of small WEBs using RCs were comparable without significant differences. Aspiration alone was not successful for larger WEBs. Rescue of larger WEBs was slightly faster (122.75 ± 41.15 s vs. 137.50 ± 54.46 s) with fewer attempts (1 vs. 1.37) when using the Microsnare compared to the Alligator device. Complications such as entrapment of the WEB in the RCs, vasospasm, perforation, or dissection were not observed. CONCLUSION: Rescue of migrated WEB devices is a feasible and effective method and 100% successful rescue rates and appropriate rescue times can be achieved for small WEBs using RCs and for larger WEBs using dedicated rescue devices (Microsnare and Alligator).

Effects of a Feedback-Demanding Stroke Clock on Acute Stroke Management: A Randomized Study.

BACKGROUND AND PURPOSE: This randomized study aimed to evaluate whether the use of a stroke clock demanding active feedback from the stroke physician accelerates acute stroke management. METHODS: For this randomized controlled study, a large-display alarm clock was installed in the computed tomography room, where admission, diagnostic work-up, and intravenous thrombolysis occurred. Alarms were set at the following target times after admission: (1) 15 minutes (neurological examination completed); (2) 25 minutes (computed tomography scanning and international normalized ratio determination by point-of-care laboratory completed); and (3) 30 minutes (intravenous thrombolysis started). The responsible stroke physician had to actively provide feedback by pressing a buzzer button. The alarm could be avoided by pressing the button before time out. Times to therapy decision (primary end point, defined as the end of all diagnostic work-up required for decision for or against recanalizing treatment), neurological examination, imaging, point-of-care laboratory, needle, and groin puncture were assessed by a neutral observer. Functional outcome (modified Rankin Scale) was assessed at day 90. RESULTS: Of 107 participants, 51 stroke clock patients exhibited better stroke-management metrics than 56 control patients. Times from door to (1) end of all indicated diagnostic work-up (treatment decision time; 16.73 versus 26.00 minutes, P<0.001), (2) end of neurological examination (7.28 versus 10.00 minutes, P<0.001), (3) end of computed tomography (11.17 versus 14.00 minutes, P=0.002), (4) end of computed tomography angiography (14.00 versus 17.17 minutes, P=0.001), (5) end of point-of-care laboratory testing (12.14 versus 20.00 minutes, P<0.001), and (6) needle times (18.83 versus 47.00 minutes, P=0.016) were improved. In contrast, door-to-groin puncture times and functional outcomes at day 90 were not significantly different. CONCLUSIONS: This study showed that the use of a stroke clock demanding active feedback significantly improves acute stroke-management metrics and, thus, represents a potential low-cost strategy for streamlining time-sensitive stroke treatment.

[Influence of the "distance to thrombus" in acute middle cerebral artery occlusion : A predictor for the clinical outcome after endovascular treatment]. / Einfluss der Distanz zum Thrombus bei akutem Verschluss der Arteria cerebi media : Ein Prädiktor für das klinische Outcome nach mechanischer Thrombektomie.

BACKGROUND: The therapy strategy of patients with acute stroke of the middle cerebral artery (MCA) is influenced by the location of the occlusion. The purpose of this study was to analyze the clinical outcome in patients with acute ischemic MCA occlusion according to the location of occlusion who underwent endovascular treatment (EVT). METHODS: A total of 54 patients (age 73 ± 15 years; 59% female) with acute ACM occlusion treated with EVT were included. In coronary reformatted CT angiography images, the distance to the thrombus (DT), i.e. the distance from the carotid T to the beginning of the thrombus, was measured. Correlations between DT, clinical symptoms, and clinical outcome of patients who underwent EVT were analyzed. RESULTS: DT correlated with clinical symptoms measured by the National Institutes of Health Stroke Scale (NIHSS; p = 0.017; R = -0.324) at baseline. DT also correlated with the modified Rankin scale after 90 days (90-day mRS; p = 0.014; R = -0.333). DT was a predictor for a good clinical outcome (mRS after 90 days) after EVT; odds ratio 1.113 (P = 0.02; 95% confidence interval [CI] 1.017-1.219). A DT >10 mm correlated significantly (p = 0.036) with a good clinical outcome (90-day mRS ≤2). CONCLUSION: DT correlates with the clinical symptoms of patients with acute MCA occlusion. In addition, DT is an independent predictor of the clinical outcome of patients suffering from acute stroke due to MCA occlusion.

Accuracy of optical coherence tomography imaging in assessing aneurysmal remnants after flow diversion.

BACKGROUND: Optical coherence tomography (OCT) is an ultra-high resolution real-time intravascular imaging method that is gaining interest in cerebrovascular applications. OBJECTIVE: To compare, in a rabbit elastase aneurysm model, digital subtraction angiography (DSA) and OCT as diagnostic tools for the assessment of aneurysmal remnants and baseline characteristics of aneurysms after flow diverter (FD) implantation. METHODS: With Institutional Animal Care and Use Committee approval, saccular aneurysms were created in 28 rabbits and treated with Derivo FDs. DSA was performed before, and immediately after, stent implantation. As a follow-up, DSA and OCT were performed 28 days after device implantation. RESULTS: DSA and OCT were successfully performed in 23 cases. OCT could not be achieved in 5 cases owing to navigational difficulties in the stent lumen with the OCT catheter. Residual aneurysms were significantly more often visible with OCT (18/23 (78%) than with DSA 12/23 (52%), p = 0.031). CONCLUSION: OCT was more sensitive than conventional angiography for the assessment of residual aneurysms at 28 days after FD implantation in an animal model.

Rescue of migrated Woven Endobridge devices using a stent-retriever-technique in a porcine model.

PURPOSE: The Woven Endobridge device (WEB) has become widely applied for the treatment of intracranial aneurysms. Complications are rare, however, especially dislocations and migrations can potentially increase poor clinical outcome. The aim of this study was to assess the feasibility and effectiveness of rescuing migrated Woven Endobridges using different stent retrievers. METHODS: In a porcine model, Woven Endobridges of different sizes (SLS 4, SLS 7, SL 5 × 3, SL 4 × 3) were placed into the axillary arteries. By means of two different stent retrievers (Solitaire Platinum and 3D Revascularization Device), a total of 20 rescue maneuvers were performed. For this purpose, the retrievers were deployed distally of the migrated Woven Endobridges. After retracting the stent retrievers partially, the Woven Endobridges were trapped within the microcatheter. Rescue rates, time, attempts and complications were assessed. RESULTS: Successful rescue of the migrated Woven Endobridges was observed in all cases (100%). Rescue was slightly faster (177.8 ± 72.8 s vs. 223.4 ± 104.1 s) with fewer attempts (1.5 ± 0.8 vs. 1.8 ± 0.9) when using the 3D Revascularization Device compared to the Solitaire Platinum. However, there were no significant differences (p = 0.327; p = 0.554). Migration of the Woven Endobridges during rescue was seen with both stent retrievers in a comparable frequency (p = 0.642). Further complications, such as entrapment of the stent-retriever-WovenEndobridge-complex at the intermediate catheter, vasospasm, perforation or dissection, were not observed. CONCLUSIONS: Rescue of migrated Woven Endobridges using stent retrievers is a feasible and effective method. Rescue rates, times and attempts with the Solitaire Platinum and 3D Revascularization Device are comparable with each other.

Why we fail: mechanisms and co-factors of unsuccessful thrombectomy in acute ischemic stroke.

PURPOSE: Mechanical thrombectomy (MT) is an effective treatment for patients suffering from acute ischemic stroke. However, recanalization fails in about 16.5% of interventions. We report our experience with unsuccessful MT and analyze technical reasons plus patient-related parameters for failure. METHODS: Five hundred ninety-six patients with acute ischemic stroke in the anterior circulation and intention to perform MT with an aspiration catheter and/or stent retriever were analyzed. Failure was defined as 0, 1, or 2a on the mTICI scale. Patients with failing MT were analyzed for interventional progress and compared to patients with successful intervention, whereby parameters included demographics, medical history, stroke presentation, and treatment. RESULTS: One hundred of the 596 (16.8%) interventions failed. In 20 cases, thrombus could not be accessed or passed with the device. Peripheral arterial occlusive disease is common in those patients. In 80 patients, true stent retriever failure occurred. In this group, coagulation disorders are associated with poor results, whereas atrial fibrillation is associated with success. The administration of intravenous thrombolysis and intake of nitric oxide donors are associated with recanalization success. Intervention duration was significantly longer in the failing group. CONCLUSION: In 20% of failing MT, thrombus cannot be reached/passed. Direct carotid puncture or surgical arterial access could be considered in these cases. In 80% of failing interventions, thrombus can be passed with the device, but the occluded vessel cannot be recanalized. Rescue techniques can be an option. Development of new devices and techniques is necessary to improve recanalization rates. Assessment of pre-existing illness could sensitize for occurring complications.

[Diagnosis and treatment of glomus tumors of the skull base and neck]. / Diagnostik und Therapie von Glomustumoren der Schädelbasis und des Halses.

Glomus tumors (paragangliomas) are rare, usually benign, neuroendocrine tumors that arise from nonchromaffin cells and can be multifocal or familial. They grow slowly, often infiltratively and rarely form metastases. A distinction is made between carotid, jugular, tympanicum and vagal tumors. Depending on the location, clinical symptoms include neck swelling, hearing loss with pulse-synchronous ear noise or cranial nerve failures (IX-XI). Diagnosis is often delayed because of nonspecific symptoms. Diagnostically, tumor expansion and perfusion can be well visualized by color Doppler sonography. In the T2-weighted MRI, the tumor is hyperintense, after contrast agent administration a strong enhancement occurs due to the strong vascularization. In DSA (digital subtraction angiography), even small glomus tumors can be detected. Therapeutically, operative tumor resection after embolization with, e.g., polyvinyl alcohol particles or liquid embolization can be performed. If the patient is in poor general condition or if the tumor is inoperable, different treatment techniques (intensity-modulated radiotherapy, gamma or cyber-knife) may be considered as a conservative therapeutic alternative.