Automated Detection of Cerebral Aneurysms on TOF-MRA Using a Deep Learning Approach: An External Validation Study.

BACKGROUND AND PURPOSE: Cerebral aneurysms yield the risk of rupture, severe disability and death. Thus, early detection of cerebral aneurysms is crucial to ensure timely treatment, if necessary. AI-based software tools are expected to enhance radiologists' performance in detecting pathologies like cerebral aneurysms in the future. Our aim was to evaluate the diagnostic performance of an artificial intelligence-based software designed to detect intracranial aneurysms on TOF-MRA. MATERIALS AND METHODS: One hundred ninety-one MR imaging data sets were analyzed using the software mdbrain for the presence of intracranial aneurysms on TOF-MRA obtained using two 3T MR imaging scanners or a 1.5T MR imaging scanner according to our clinical standard protocol. The results were compared with the reading of an experienced radiologist as a criterion standard to measure the sensitivity, specificity, positive and negative predictive values, and accuracy of the software. Additionally, detection rates depending on size, morphology, and location of the aneurysms were evaluated. RESULTS: Fifty-four aneurysms were detected by the expert reader. The overall sensitivity of the software for the detection of cerebral aneurysms was 72.6%, the specificity was 87.2%, and the accuracy was 82.6%. The positive predictive value was 67.9%, and the negative predictive value was 88.5%. We observed a sensitivity of 100% for saccular aneurysms of >5 mm without signs of thrombosis and low detection rates for fusiform or thrombosed aneurysms of 33.3% and 16.7%, respectively. Of 8 aneurysms that were not included in the initial written reports but were detected by the expert reader, retrospectively, 4 were detected by the software. CONCLUSIONS: Our data suggest that the software can assist radiologists in reporting TOF-MRA. The software was highly reliable in detecting saccular aneurysms, while for fusiform or thrombosed aneurysms, further improvements are needed. Further studies are necessary to investigate the impact of the software on detection rates, interrater reliability, and reading times.

Treatment of Proximal Posterior Inferior Cerebellar Artery Aneurysms by Intrasaccular Flow Disruption: A Multicenter Experience.

BACKGROUND AND PURPOSE: Treatment of PICA aneurysms can be technically challenging by either surgical or endovascular means. Our aim was to report our preliminary experience with intrasaccular flow disruption using the Woven EndoBridge (WEB) for the treatment of proximal PICA aneurysms. MATERIALS AND METHODS: Sixteen PICA aneurysms treated with the WEB at 3 institutions were retrospectively reviewed. Baseline patient and aneurysm characteristics, procedural specifics, clinical outcomes, and angiographic results were evaluated. RESULTS: All aneurysms were located at the proximal, anteromedullary segment of the PICA. Seven aneurysms were ruptured. The median aneurysm size was 3.9 mm (range, 2-12 mm), and all aneurysms were wide-neck. WEB deployment failed in 1 case due to WEB protrusion in a small PICA aneurysm. Additional stent implantation was required for 2 aneurysms to improve intra-aneurysmal WEB positioning. One patient developed a partial posterior cerebral artery territory infarction with transient hemianopsia. Intraoperative rerupture of a ruptured aneurysm could be immediately stopped by WEB deployment due to intrasaccular stasis; however, it might have contributed to a slight disability of the patient. At last angiographic follow-up, 12/15 aneurysms (80%) were completely occluded and 3/15 (20%) had a neck remnant. CONCLUSIONS: The preliminary results indicate that WEB treatment of proximal PICA aneurysms is feasible with a reasonable safety and efficacy profile. The advantages of intrasaccular flow disruption include preservation of the PICA, durable aneurysm occlusion, and omission of antiplatelet therapy. The low-profile WEB 17 delivery system might enable navigation to distal PICA aneurysms, which needs to be addressed further.

Magnetic particle imaging for artifact-free imaging of intracranial flow diverter stents: A phantom study.

PURPOSE: Magnetic Particle Imaging (MPI) is a new, background- and radiation-free tomographic imaging method that enables near real-time imaging of superparamagnetic iron-oxide nanoparticles (SPIONs) with high temporal and spatial resolution. This phantom study aims to investigate the potential of MPI for visualization of the stent lumen in intracranial flow diverters (FD). METHODS: Nitinol FD of different dimensions (outer diameter: 3.5 mm, 4.0 mm, 5.5 mm; total length: 22-40 mm) were scanned in vascular phantoms in a custom-built MPI scanner (in-plane resolution: ~ 2 mm, field of view: 65 mm length, 29 mm diameter). Phantoms were filled with diluted (1:50) SPION tracer agent Ferucarbotran (10 µmol (Fe)/ml; NaCL). Each phantom was measured in 32 different projections (overall acquisition time per image: 3200 ms, 5averages). After image reconstruction from raw data, two radiologists assessed image quality using a 5-point Likert scale. The signal intensity profile was measured using a semi-automatic evaluation tool. RESULTS: MPI visualized the lumen of all FD without relevant differences between the stented vessel phantom and the reference phantom. At 3.5 mm image quality was slightly inferior to the larger diameters. The FD themselves neither generated an MPI signal nor did they lead to relevant imaging artifacts. Ratings of both radiologists showed no significant difference, interrater reliability was good (ICC 0.84). A quantitative evaluation of the signal intensity profile did not reveal any significant differences (p > 0.05) either. CONCLUSION: MPI visualizes the lumen of nitinol FD stents in vessel phantoms without relevant stent-induced artifacts.

Considerations for Antiplatelet Management of Carotid Stenting in the Setting of Mechanical Thrombectomy: A Delphi Consensus Statement.

BACKGROUND AND PURPOSE: There are only few data and lack of consensus regarding antiplatelet management for carotid stent placement in the setting of endovascular stroke treatment. We aimed to develop a consensus-based algorithm for antiplatelet management in acute ischemic stroke patients undergoing endovascular treatment and simultaneous emergent carotid stent placement. MATERIALS AND METHODS: We performed a literature search and a modified Delphi approach used Web-based questionnaires that were sent in several iterations to an international multidisciplinary panel of 19 neurointerventionalists from 7 countries. The first round included open-ended questions and formed the basis for subsequent rounds, in which closed-ended questions were used. Participants continuously received feedback on the results from previous rounds. Consensus was defined as agreement of ≥70% for binary questions and agreement of ≥50% for questions with >2 answer options. The results of the Delphi process were then summarized in a draft manuscript that was circulated among the panel members for feedback. RESULTS: A total of 5 Delphi rounds were performed. Panel members preferred a single intravenous aspirin bolus or, in jurisdictions in which intravenous aspirin is not available, a glycoprotein IIb/IIIa receptor inhibitor as intraprocedural antiplatelet regimen and a combination therapy of oral aspirin and a P2Y12 inhibitor in the postprocedural period. There was no consensus on the role of platelet function testing in the postprocedural period. CONCLUSIONS: More and better data on antiplatelet management for carotid stent placement in the setting of endovascular treatment are urgently needed. Panel members preferred intravenous aspirin or, alternatively, a glycoprotein IIb/IIIa receptor inhibitor as an intraprocedural antiplatelet agent, followed by a dual oral regimen of aspirin and a P2Y12 inhibitor in the postprocedural period.

Antiplatelet Management for Stent-Assisted Coiling and Flow Diversion of Ruptured Intracranial Aneurysms: A DELPHI Consensus Statement.

BACKGROUND AND PURPOSE: There is a paucity of data regarding antiplatelet management strategies in the setting of stent-assisted coiling/flow diversion for ruptured intracranial aneurysms. This study aimed to identify current challenges in antiplatelet management during stent-assisted coiling/flow diversion for ruptured intracranial aneurysms and to outline possible antiplatelet management strategies. MATERIALS AND METHODS: The modified DELPHI approach with an on-line questionnaire was sent in several iterations to an international, multidisciplinary panel of 15 neurointerventionalists. The first round consisted of open-ended questions, followed by closed-ended questions in the subsequent rounds. Responses were analyzed in an anonymous fashion and summarized in the final manuscript draft. The statement received endorsement from the World Federation of Interventional and Therapeutic Neuroradiology, the Japanese Society for Neuroendovascular Therapy, and the Chinese Neurosurgical Society. RESULTS: Data were collected from December 9, 2019, to March 13, 2020. Panel members achieved consensus that platelet function testing may not be necessary and that antiplatelet management for stent-assisted coiling and flow diversion of ruptured intracranial aneurysms can follow the same principles. Preprocedural placement of a ventricular drain was thought to be beneficial in cases with a high risk of hydrocephalus. A periprocedural dual, intravenous, antiplatelet regimen with aspirin and a glycoprotein IIb/IIIa inhibitor was preferred as a standard approach. The panel agreed that intravenous medication can be converted to oral aspirin and an oral P2Y12 inhibitor within 24 hours after the procedure. CONCLUSIONS: More and better data on antiplatelet management of patients with ruptured intracranial aneurysms undergoing stent-assisted coiling or flow diversion are urgently needed. Panel members in this DELPHI consensus study preferred a periprocedural dual-antiplatelet regimen with aspirin and a glycoprotein IIb/IIIa inhibitor.

Low-Profile Intra-Aneurysmal Flow Disruptor WEB 17 versus WEB Predecessor Systems for Treatment of Small Intracranial Aneurysms: Comparative Analysis of Procedural Safety and Feasibility.

BACKGROUND AND PURPOSE: The Woven EndoBridge 17 has recently been introduced to the market for facilitated endovascular treatment of small bifurcation aneurysms (≤7 mm) with low-profile microcatheters. We compared the Woven EndoBridge 17 with its predecessor versions in terms of procedural safety and feasibility. MATERIALS AND METHODS: This was a multicenter review of aneurysms ranging from 3 to 7 mm treated with the Woven EndoBridge between 2011 and 2019. Aneurysm characteristics, procedural parameters, and complications were retrospectively compared between treatment with the Woven EndoBridge 17 and a control group that was treated with its predecessor versions, using inverse probability of treatment weighting. RESULTS: Thirty-eight aneurysms treated with a Woven EndoBridge 17 (mean size, 4.9 ± 1.5 mm) and 70 treated with a predecessor version of the Woven EndoBridge 17 (mean size, 5.6 ± 1.4 mm) were included. The predecessor version of the Woven EndoBridge 17 had a higher failure rate (10.3%) than the Woven EndoBridge 17 (0%, P = .05). Additional stent placement was performed more often with the predecessor version of the Woven EndoBridge 17 (10.0%) than with the Woven EndoBridge 17 (2.6%, adjusted P = .005). The predecessor version of the Woven EndoBridge 17 was associated with a higher thromboembolic event rate (14.3%) than the Woven EndoBridge 17 (5.3%, adjusted P = .002). Neurologic complications (Woven EndoBridge 17: 2.6%; predecessor version of the Woven EndoBridge 17: 2.9%, adjusted P = 1.0) and immediate complete aneurysm occlusion rates (Woven EndoBridge 17: 57.9%; predecessor version of the Woven EndoBridge 17: 54.3%, adjusted P = .21) did not differ significantly between groups. CONCLUSIONS: In the current study, the Woven EndoBridge 17 was associated with a potentially lower thromboembolic event rate than the predecessor version of the Woven EndoBridge 17, without compromising the immediate aneurysm occlusion rate. Long-term clinical and angiographic outcome analysis will be necessary to draw a definite conclusion.

Impact of intravenous thrombolysis and emergent carotid stenting on reperfusion and clinical outcomes in patients with acute stroke with tandem lesion treated with thrombectomy: a collaborative pooled analysis.

BACKGROUND AND PURPOSE: Tandem anterior circulation lesions in the setting of acute ischemic stroke (AIS) are a complex endovascular situation that has not been specifically addressed in trials. We determined the predictors of successful reperfusion and good clinical outcome at 90 days after mechanical thrombectomy (MT) in patients with AIS with tandem lesions in a pooled collaborative study. METHODS: This was a retrospective analysis of consecutive patients presenting to 18 comprehensive stroke centers with AIS due to tandem lesion of the anterior circulation who underwent MT. RESULTS: A total of 395 patients were included. Successful reperfusion (modified thrombolysis in cerebral infarction score 2b-3) was achieved in 76.7%. At 90 days, 52.2% achieved a good outcome (modified Rankin Scale score 0-2), 13.8% suffered a parenchymal hematoma and 13.2% were dead. Lower National Institutes of Health Stroke Scale score [odds ratio (OR), 1.26; 95% confidence intervals (CI), 1.07-1.48, P = 0.004], Alberta Stroke Program Early CT Score ≥7 (OR, 2.00; 95% CI, 1.07-3.43, P = 0.011), intravenous thrombolysis (OR, 1.47; 95% CI, 1.01-2.12, P = 0.042) and stenting of the extracranial carotid lesion (OR, 1.63; 95% CI, 1.04-2;53, P = 0.030) were independently associated with successful reperfusion. Lower age (OR, 1.58; 95% CI, 1.26-1.97, P < 0.001), absence of hypercholesterolemia (OR, 1.77; 95% CI, 1.10-2.84, P = 0.018), lower National Institutes of Health Stroke Scale scores (OR, 2.04; 95% CI, 1.53-2.72, P < 0.001), Alberta Stroke Program Early CT Score ≥7 (OR, 2.75; 95% CI, 1.24-6.10, P = 0.013) and proximal middle cerebral artery occlusion (OR, 1.59; 95% CI, 1.03-2.44, P = 0.035) independently predicted a good 90-day outcome. CONCLUSIONS: Intravenous thrombolysis and emergent stenting of the extracranial carotid lesion were predictors of a successful reperfusion after MT of patients with AIS with tandem lesion of the anterior circulation.

Bacterial Contamination During Diagnostic and Interventional Neuroangiography is a Frequent Finding: But Does It Matter? An Observational Study.

INTRODUCTION: Bacterial contamination during angiographic procedures is a potential source of bacteremia. It is largely unknown whether it is clinically relevant. Our aim was to evaluate the incidence of contamination of liquids during catheter-based neuroangiographic examinations, the spectrum of microorganisms, a comparison of two different trolley-settings, and a follow-up of all patients with regard to clinical and lab signs of infection. METHODS: A total of 170 patients underwent either diagnostic angiography (n = 111) or arterial neuroendovascular procedures (n = 59). To study the impact of airborne contamination of sterile liquids, we randomly assigned equal numbers of procedures to two distinct setups. Group A with standard open-surface bowls and group B with repetitive coverage of liquids throughout the procedure. Patient preparation was performed with utmost care. After each procedure, samples of the liquids were sent for microbiological evaluation. Patients were followed for signs of infection (fever, white blood cell count, C-reactive-protein). RESULTS: Of all samples, 25.3 % were contaminated. Contamination consisted of resident skin microbiota only and was more common with procedures (28.8 %) than with diagnostic angiography (23.4 %) and less common in uncovered (23.5 %) than in covered bowls (27.1 %). However, these differences were insignificant. None of the patients developed clinical or lab signs of infection. CONCLUSION: Contamination during diagnostic and interventional angiography does occur and cannot be avoided by intermittent coverage. Despite a surprisingly high incidence, our findings support the common strategy that antibiotic coverage is unnecessary in most patients undergoing arterial angiography as it lacks clinical impact. Airborne contamination does not appear to play a role.

Effects of standardized acoustic stimulation in premature infants: a randomized controlled trial.

OBJECTIVE: The objective of this study was to investigate the effects of recorded lullabies and taped maternal voice in premature infants. STUDY DESIGN: Sixty-two preterm infants in a stable condition with 30<37 weeks of gestation and <10 days of postnatal age were randomly assigned to hear (A) recorded lullabies or (B) taped maternal voice for 30 min each evening during 14 consecutive days or (C) receive no standardized acoustic stimulation (control group). Heart rate and respiratory rate were recorded daily before, during and after the intervention (A and B) or a comparable period with no intervention (C), whereas activity was measured on days 1, 7 and 14 of the intervention using accelerometers. RESULTS: Both interventions led to a significant decrease in heart rate and respiratory rate during and after the stimulation when compared with the control group. The changes were more pronounced in infants with higher gestational ages (P=0.001). Lower activity was measured during the intervention when compared with the control group (P<0.01). CONCLUSIONS: Standardized acoustic stimulation with recorded lullabies and taped maternal voice led to a decrease in heart rate and respiratory rate, and was associated with lower activity. Whether this indicates a reduced stress reaction needs to be investigated in further studies.

Stent Retriever Thrombectomy in Patients Who Are Ineligible for Intravenous Thrombolysis: A Multicenter Retrospective Observational Study.

BACKGROUND AND PURPOSE: Intravenous thrombolysis with rtPA is the standard of care for patients with acute ischemic stroke within 4.5 hours after symptom onset. However, a considerable number of patients are ineligible for IV thrombolysis due to various contraindications. Recent studies have proved the superiority of mechanical thrombectomy for patients with large-vessel occlusions in combination with IV rtPA compared with IV rtPA alone. We aimed to demonstrate the efficacy of mechanical thrombectomy for patients who are ineligible for IV rtPA. MATERIALS AND METHODS: Patients from the stroke registries of 4 dedicated centers who were treated with mechanical thrombectomy from January 2010 to October 2014 were retrospectively evaluated. Inclusion criteria were the following: acute stroke due to proved large-artery occlusion, ineligibility for IV thrombolysis, and a timeframe of ≤4.5 hours between stroke and the start of mechanical thrombectomy. Recanalization success, periprocedural complications, clinical outcome, and hemorrhages were evaluated. RESULTS: One hundred thirty endovascular recanalization procedures were identified. The locations were the following: proximal ICA in 17 (13.1%), terminus ICA in 25 (19.2%), M1 segment in 77 (59.2%), and M2 segment in 11 (8.5%). TICI 2b/3 results were achieved in 101 (77.7%), and an mRS score of 0-2 in 47 patients (37.9%). There was a significant correlation between TICI 2b/3 results and good clinical outcomes (87.2% versus 6.8%; P = .048). A good clinical result was most frequent when recanalization was achieved within 4.5 hours (37/74 = 50% versus 10/50 = 20.0%; P = .001). Symptomatic hemorrhage occurred in 13.1% of patients; mortality was 24.2%. Periprocedural complications were recorded in 10 patients (7.7%). CONCLUSIONS: Mechanical thrombectomy can achieve good clinical outcomes in patients with acute large-artery occlusion ineligible for IV thrombolysis, in particular when recanalization is reached early.

Initial Clinical Experience with a New Self-Expanding Nitinol Microstent for the Treatment of Wide-Neck Intracranial Cerebral Aneurysms: The Acandis Acclino Stent.

BACKGROUND AND PURPOSE: The Acclino is a laser-cut closed-cell microstent composed of nitinol. It was developed for stent-assisted coiling of wide-neck intracranial aneurysms. The key feature of the stent is its deployability via low-profile microcatheters with an inner diameter of 0.0165 inch, which are also suited for coil deployment. The objective of this study was to evaluate the safety and feasibility as well as the immediate and mid-term results of this new device. MATERIALS AND METHODS: Our database was screened for all Acclino-based stent-assisted intracranial coil embolizations since its introduction to the European market in June 2012. Case files and imaging data were retrospectively analyzed for angiographical and clinical outcome parameters, including immediate and mid-term modified Raymond-Roy aneurysm occlusion classification (RROC) rates and procedural complications. RESULTS: Fourteen patients comprising 14 aneurysms (9 unruptured and 5 ruptured) were treated with the Acclino. All except for a dissecting one were wide-neck saccular aneurysms. Immediate complete occlusion (RROC1) was observed in 8/14 cases (57%), a residual neck (RROC2) in 4/14 (29%), and a persistent filling of the dome (RROC 3) in 1/14 cases (7%). An in-stent thrombus formation in one case (7%) was medically resolved without neurological deficit. Follow-up was available in 9/14 cases (64%) after a mean of 137 days (SD ± 50). All followed cases depicted a complete occlusion (RROC1). CONCLUSIONS: The Acclino microstent showed a satisfactory safety profile and a promising rate of immediate and mid-term complete aneurysm occlusion for stent-assisted coil embolization in wide-neck intracranial aneurysms, warranting further investigation of the device.

Mechanical thrombectomy in tandem occlusion: procedural considerations and clinical results.

INTRODUCTION: Acute tandem occlusions of the cervical and distal internal carotid artery (ICA) or middle cerebral artery (MCA) are associated with major stroke with intravenous (i.v.) thrombolysis alone in approximately 90 % of patients. The data on endovascular management of tandem occlusions is still limited. The purpose of this study was to review technical aspects and the current state of the literature on acute ICA stenting in combination with stent retriever-based intracranial thrombectomy. METHODS: We retrospectively reviewed the data of 37 consecutive patients with tandem occlusions including clinical parameters, angiographic results, procedural aspects, complications, and hemorrhages. RESULTS: Median National Institutes of Health Stroke Scale (NIHSS) on admission was 17 (3-30). Intracranial thrombectomy was performed prior to ICA stenting in 25/37 (67.6 %) and after stenting in 12/37 (32.4 %) patients. ICA stenting was successful in all cases, and a thrombolysis in cerebral infarction (TICI) scale 2b/3 result was achieved in 27/37 (73 %) cases. The mean angiography time was significantly shorter in the "thrombectomy first" group (43.1 ± 30.8 vs. 110.8 ± 43.0 min, p < 0.001), and more patients had favorable outcomes after 3 months (13/25 = 52.0 vs. 4/12 = 33.3 %, p = 0.319). In this group, intermediate catheters were used and successfully prevented embolism to unaffected territories in all cases. CONCLUSION: Acute stenting of the cervical ICA in combination with intracranial thrombectomy was technically feasible and safe in our series. Thrombectomy prior to proximal stenting was associated with shorter reperfusion times and a tendency towards better clinical outcome leading to a good outcome in about 50 % of the patients. Therefore, we recommend this approach in tandem occlusion requiring stent angioplasty.

Endovascular treatment of acute intracerebral artery occlusions with the solitaire stent: single-centre experience with 108 recanalization procedures.

BACKGROUND AND PURPOSE: Stent retrievers are currently displacing 'classical' thrombectomy devices for recanalization in acute ischaemic stroke. The aim of our study was to show the procedural efficacy and safety of the Solitaire stent retriever as part of our multimodality endovascular approach in the treatment of ischaemic stroke. METHODS: Between March 2008 and December 2009, 104 patients [53 females (51%), 51 males (49%), mean age 67.3 years (range 31-96)] with 108 territorial occlusions were treated with the Solitaire stent alone or in conjunction with other endovascular stroke devices. All patients were referred to our service after clinical evaluation by a team of stroke neurologists as part of our standard treatment algorithm with 0.9 mg/kg i.v. recombinant tissue-type plasminogen activator and endovascular continuation of treatment in CT angiography-proven main branch occlusion. The time of angiography was defined as the moment of groin puncture. Final reperfusion success was rated according to the Thrombolysis in Cerebral Infarction (TICI) scale; the first persistent Thrombolysis in Myocardial Infarction (TIMI) 2/3 reperfusion was used for time-to-reperfusion measures. RESULTS: Fifty-eight patients were treated in conjunction with intravenous lysis, 32/104 received intra-arterial lytics. Twenty-five territories were treated with the Solitaire alone; the remaining 83 were treated with a combination of mechanical thrombectomy devices or aspiration thrombectomy followed by or in conjunction with the Solitaire. The most frequent combination was a proximal aspiration/distal access catheter and Solitaire (62/108). In 15/108 procedures, temporary stenting without thrombectomy was performed. Eighty-three successful thrombectomy attempts were performed in the remaining 93 territories. The mean number of Solitaire passes was 2.46 (median 2, max. 12). The mean time from onset to reperfusion was 265 min (range 56-1,031), median 230 min; the mean angio-to-reperfusion time was 47 min (5-186), median 38.5 min. A subanalysis showed a significant reduction of the angio-to-reperfusion time when the Solitaire was used (48.7 vs. 68 min). The rate of final TICI 2b/3 reperfusion was 79% for the anterior and 77.9% for the posterior circulation (TIMI 2/3 for both: 92.5%). During or after the first deployment of the Solitaire, 72.8% showed TIMI 2/3 reperfusion. The mean National Institute of Health Stroke Scale score on admission was 15.3 and decreased by 7.8 points at clinical discharge. The overall mortality at discharge was 16% in the anterior and 47.8% in the posterior circulation group. There were 2 cases of periprocedural intracranial haemorrhage, unrelated to the Solitaire, 6 patients had evidence of subarachnoid haemorrhage, 2 potentially related to the Solitaire deployment. In 4/108 territories, thrombus migration to previously unaffected territories was noted. Vasospasm was seen in 13% of the target vessels. One device was inadvertently detached during retrieval. All these complications had no clinical consequence. CONCLUSIONS: Our single-centre experience proves the technical feasibility and safety of the Solitaire for the treatment of acute intracranial vessel occlusion and approves previous reports with smaller patient numbers. Further multicentre studies with a randomized and prospective design will be necessary to verify the results.

Intrasaccular flow-disruption treatment of intracranial aneurysms: preliminary results of a multicenter clinical study.

BACKGROUND AND PURPOSE: The endovascular treatment of intracranial aneurysms with unfavorable anatomy (large aneurysms, wide-neck) is frequently challenging and is also associated with a high incidence of significant recurrences. The WEB, an intrasaccular flow disrupter, was designed for use in this type of aneurysm. We report our early experience with this device in this multicenter study. MATERIALS AND METHODS: Twenty patients with 21 aneurysms were treated by using the WEB in 3 European centers. The ability to successfully deploy the WEB, immediate posttreatment angiographic results, adverse events, clinical outcome, and angiographic follow-up results were recorded. RESULTS: Aneurysm location was the ICA (4/21, 19.1%), MCA (8/21, 38.1%), AcomA (5/21, 23.8%), and BA (4/21, 19.1%). No treatment failures were reported. Treatment was performed exclusively with the WEB in 16/21 (76.2%) patients. Additional treatment (coiling and/or stent placement) was used in 5/21 (23.8%) patients. One patient (4.8%) experienced transient clinical worsening (mRS 1 at 1 month, mRS 0 at 3 months) related to a thromboembolic event. Inadvertent detachment of the WEB was observed, and the WEB was retrieved in 1 patient, without adverse effects. In the short-term follow-up (2-8 months), adequate occlusion (total occlusion or neck remnant) was observed in 80.0% of aneurysms. CONCLUSIONS: Intrasaccular flow disruption is a new endovascular approach for aneurysm treatment. In our preliminary experience, this treatment was feasible and mostly used in bifurcation aneurysms (MCA, BA, ICA) with unfavorable anatomy. Further studies are needed to precisely evaluate the indications, safety, and efficacy of this new technique.

Stent angioplasty of intracranial stenosis: single center experience of 54 cases.

PURPOSE: The aim of the study was to retrospectively evaluate the safety and efficacy of stent angioplasty of symptomatic intracranial stenosis in a single center experience. MATERIALS AND METHODS: Between November 2006 and September 2009 a total of 54 stent angioplasties were performed in 49 patients and of these 46 were done for symptomatic intracranial high-grade (>70%) stenoses and 8 for complete vessel occlusions in acute stroke. All elective treatments were carried out with patients under antithrombotic/anticoagulant medication. Self-expandable stents were used in 42 cases and balloon-expandable stents in 12 cases. RESULTS: Stent angioplasty was successful in 53 out of 54 cases (98%). Periprocedural complications occurred in 6 patients, including 2 dissections, 1 contrast-mediated toxic reaction and 1 thromboembolic event with transient neurological deficits but did not cause permanent neurological deficits, in any of the cases. Adverse events within 30 days after intervention occurred in 11 of the 49 patients (20.4%) of which 4 were scheduled patients (8.3%) and 7 were treated for acute stroke with complete vessel occlusions (87.5%). Overall there were 9 cases of restenosis (7 out of 9>90% stenoses and 2 complete vessel occlusions), 5 out of 9 were asymptomatic, 4 out of 9 had a transient ischemic attack and 1 developed a major stroke. Two complete in-stent thromboses were seen in acute stroke patients with initial complete occlusion within 24 h after recanalization. One restenosis and one complete occlusion occurred under double antiplatelet medication, 4 out of 9 restenoses occurred under aspisol medication and 3 out of 9 after antiplatelet medication was discontinued. In 2 out of 9 restenoses, balloon-expandable stents had been used, the remaining 7 had been treated with self-expanding stents, 5 out of 9 restenoses were treated by balloon-angioplasty alone, in 3 out of 9 an additional stent had to be placed and 1 asymptomatic occlusion was left untreated. CONCLUSIONS: The results demonstrate the technical feasibility and satisfactory success rates of stent angioplasty in intracranial atherosclerotic stenoses. The procedural success rate was 98% and the overall rate of adverse events was 20.4%. The rate of adverse events was high in unstable patients (87.5%) treated without antiplatelet premedication, especially in the setting of an acute stroke. In stable patients the rate of adverse events was much lower (8.3%). Future development of dedicated stents and a better understanding of factors that predispose to restenosis may help to further decrease the rate of periprocedural and postprocedural adverse events thus helping to improve both short-term and long-term outcome after intracranial stent angioplasty.

Early venous drainage after successful endovascular recanalization in ischemic stroke -- a predictor for final infarct volume?

INTRODUCTION: Peri-ischemic early venous filling (PEVD) has been reported to occur at certain stages of brain infarction and has previously been termed as "luxury perfusion". We report on the significance of PEVD after a successful endovascular recanalization. METHODS: We retrospectively evaluated all patients who underwent endovascular stroke treatment from February 2006 to April 2010 in two centers. PEVD was rated as present or absent. Infarction was evaluated on computed tomography (CT) ≥ 18 h post-treatment. Localization of the PEVD and the infarction was noted for the anterior and posterior circulation; for the anterior circulation, also deep and superficial veins/brain regions were defined. RESULTS: A total of 151 of the 175 patients developed an infarct. Of these 151 patients, 118 had PEVD (sensitivity 78.1%); meanwhile, 20 of 24 patients without an infarction had no PEVD (specificity 83.3%). Consistent localization of the PEVD and the infarct was seen in 107/151 patients (70.9%); in 28 of these 107 cases, the territory of PEVD was smaller than the infarct (26.2%) and exceeded it in 7/107 patients (5.6%). Territorial congruency of the PEVD and the final infarct was 57.6-75% for deep/superficial brain regions of the anterior, but only 16.7% for the posterior circulation. Separate evaluation for the anterior circulation resulted in a 94.9% sensitivity and an 81.0% specificity. CONCLUSION: PEVD is a potential angiographic predictor for irreversible regional tissue damage and subsequent infarction despite successful recanalization. This finding deserves further studies and may influence therapeutic decisions such as post-treatment anticoagulative medication. It may also be considered in potential refined classifications of angiographic reperfusion success in the future.

Step and shoot coronary CT angiography using 256-slice CT: effect of heart rate and heart rate variability on image quality.

OBJECTIVE: To evaluate the effect of heart rate variability (HRV) and heart rate (HR) on intra-image "motion" and inter-image "stairstep" artefacts in step-and-shoot coronary CT angiography (CCTA) using a wide detector CT scanner. METHODS: 66 patients underwent step-and-shoot CCTA using 256-slice CT. Patients were divided into two groups (Group 1: HR <65 bpm, Group 2 ≥65bpm). Motion artefacts were quantified using a 5-point-scale. Stairstep artefacts were defined by measurements of misalignment. Image noise, contrast-to-noise-ratio (CNR), signal-to-noise-ratio (SNR), and radiation dose were assessed. RESULTS: Mean HR was 66 ± 16.7 bpm (range: 45-125 bpm) and mean HRV was 10.7 ± 17.5 bpm. A significant correlation between HR and stairstep artefacts (r = 0.46, p < 0.001) and motion artefacts (r = 0.63, p < 0.001) was found. Group 2 showed significantly increased step artefacts with a mean misalignment of 1.4 mm compared to 0.4 mm in Group 1 (p < 0.001). There was no significant effect of HRV on stairstep artefacts (r = 0.15, p = 0.416) and motion artefacts (r = 0.13, p = 0.311). No significant differences in image noise, CNR, SNR, and radiation dose were seen. CONCLUSIONS: Unlike CCTA using narrow CT detectors, HRV has no significant effect on motion and stairstep artefacts using a wide CT detector with high z-coverage. However, a higher HR still increases stairstep and motion artefacts.