Evaluation of a novel polymer coil for endovascular occlusion of intracranial aneurysms in a rabbit model

BACKGROUND AND PURPOSE

The results of the preclinical study of a novel polymer coil in treatment of elastase induced aneurysms will be presented in this paper.

MATERIAL AND METHODS

We induced 16 aneurysms in 16 New Zealand white rabbits at the origin of the right common carotid artery at the brachiocephalic trunk. Newly developed polymer coils in both groups for six aneurysms each and platinum coils for two aneurysms each were used. Control angiographies followed in both groups immediately after coiling as well as in the first eight animals 30 days after intervention (30 days group) and in the other eight animals 90 days after (90 days group). An explanation and histological evaluation of the treated aneurysms followed.

RESULTS

The 12 animals in which the aneurysms were treated with polymer coils showed a complete occlusion (grade IV) in only 6 out of 12 aneurysms (50%), an almost complete occlusion (grade III) in 5 out of 12 (42%) and an incomplete occlusion in the treatment of one aneurysm (8%). Histologically, we observed a significantly more pronounced inflammatory response and neoangiogenesis in aneurysms treated with polymer coils only in the 30 days group.

CONCLUSION

Most difficulties and concerns with the polymer coils were related to the flexibility and detachment behaviour. Therefore, and due to the technical challenges of delivery, the novel polymer coil cannot be considered an alternative to the current platinum coils.

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.

Learning Curve for Flow Diversion of Posterior Circulation Aneurysms: A Long-Term International Multicenter Cohort Study

BACKGROUND AND PURPOSE

Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes.

MATERIALS AND METHODS

A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals.

RESULTS

A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms (P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm (P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 (P = .34).

CONCLUSIONS

This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications.

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.

Long-term follow-up MRI shows no hastening of adjacent segment degeneration following cervical disc arthroplasty

Cervical disc arthroplasty is an established procedure, but studies with data on long-term clinical outcome, reoperation for symptomatic adjacent segment degeneration (sASD), and degenerative changes based on MRI findings are rare. Thus, a file review was performed and patients with complete documentation of neurological status at preoperative, postoperative, 12 month, 3–4 years follow-up including surgical reports for reoperation with a minimum follow-up of 9 years were included. Final follow-up assessment included a physical examination, assessment of pain levels, Odoms criteria, Neck disability index. The degeneration of each cervical segment at preoperative and at final follow-up was assessed using an MRI. Forty-six out of 68 included patients participated, the mean follow-up was 11 (range 9–15) years, at which 71.7% of patients were free of arm pain, 52.2% of patients were free of neck pain, 63% of patients had no sensory dysfunction, and full motor strength was noted in 95.6% of patients. The clinical success rate was 76.1%, the mean NDI was 12%. Overall repeated procedure rate was 17%, the reoperation rate for sASD was 9%, and removal of CDA was performed in 4%. MRI showed progressive degeneration but no significant changes of SDI from preoperative to final follow-up.

[Cerebral dural arteriovenous fistulas]

CLINICAL ISSUE

The cerebral dural arteriovenous (AV) fistula is a rare cerebral vascular malformation. Clinical presentation varies from asymptomatic to acute intracranial bleeding. Classification is based on the venous drainage with a risk assessment of bleeding. The carotid-cavernous fistula is a subtype with its own classification and treatment approaches.

PRACTICAL RECOMMENDATIONS

Nowadays, dural fistulas can be diagnosed using high-resolution and time-resolved tomographic methods. Catheter angiography with subsequent interdisciplinary discussion should be performed for precise classification and therapy planning. Both endovascular and surgical treatment methods are available.

Procedural Outcome Following Stent-Assisted Coiling for Wide-Necked Aneurysms Using Three Different Stent Models: A Single-Center Experience

Previous case series have described the safety and efficacy of different stent models for stent-assisted aneurysm coiling (SAC), but comparative analyses of procedural results are limited. This study investigates the procedural outcome and safety of three different stent models (Atlas™, LEO+™ (Baby) and Enterprise™) in the setting of elective SAC treated at a tertiary neuro-endovascular center. We retrospectively reviewed all consecutively treated patients that received endovascular SAC for intracranial aneurysms between 1 July 2013 and 31 March 2020, excluding all emergency angiographies for acute subarachnoid hemorrhage. The primary procedural outcome was the occlusion rate evaluated with the Raymond–Roy occlusion classification (RROC) assessed on digital subtraction angiography (DSA) at 6- and 12-month follow-up. Safety assessment included periprocedural adverse events (i.e., symptomatic ischemic complications, symptomatic intracerebral hemorrhage, iatrogenic perforation, dissection, or aneurysm rupture and in-stent thrombosis) and in-house mortality. Uni- and multivariable logistic regression analyses were performed to identify patient baseline and aneurysm characteristics that were associated with complete aneurysm obliteration at follow-up. A total of 156 patients undergoing endovascular treatment via SAC met the inclusion criteria. The median age was 62 years (IQR, 55–71), and 73.7% (115) of patients were female. At first follow-up (6-month) and last available follow-up (12 and 18 months), complete aneurysm occlusion was observed in 78.3% (90) and 76.9% (102) of patients, respectively. There were no differences regarding the occlusion rates stratified by stent model. Multivariable logistic analysis revealed increasing dome/neck ratio (adjusted odds ratio (aOR), 0.26.; 95% CI, 0.11–0.64; p = 0.003), increasing neck size (aOR, 0.70; 95% CI, 0.51–0.96; p = 0.027), and female sex (aOR, 4.37; 95% CI, 1.68–11.36; p = 0.002) as independently associated with treatment success. This study showed comparable rates of complete long-term aneurysm obliteration and safety following SAC for intracranial aneurysm with three different stent-models highlighting the procedural feasibility of this treatment strategy with currently available stent-models. Increased neck size and a higher dome/neck ratio were independent variables associated with less frequent complete aneurysm obliteration.

Vascular Response on a Novel Fibrin-Based Coated Flow Diverter

Purpose

Due to thromboembolic complications and in-stent-stenosis after flow diverter (FD) treatment, the long-term use of dual antiplatelet treatment (DAPT) is mandatory. The tested nano-coating has been shown to reduce material thrombogenicity and promote endothelial cell proliferation in vitro. We compared the biocompatibility of coated (Derivo Heal) and non-coated (Derivo bare) FDs with DAPT in an animal model.

Methods

Derivo® bare (n = 10) and Derivo® Heal (n = 10) FD were implanted in the common carotid arteries (CCAs) of New Zealand white rabbits. One additional FD, alternately a Derivo bare (n = 5) or Derivo Heal (n = 5), was implanted in the abdominal aorta (AA) for assessment of the patency of branch arteries. Histopathological examinations were performed after 28 days. Angiography was performed before and after FD implantation and at follow-up.

Results

Statistical analysis of the included specimens showed complete endothelialization of all FDs with no significant differences in neointima thickness between Derivo® bare and Derivo® Heal (CCA: p = 0.91; AA: p = 0.59). A significantly reduced number of macrophages in the vessel wall of the Derivo Heal was observed for the CCA (p = 0.02), and significantly reduced fibrin and platelet deposition on the surface of the Derivo Heal was observed for the AA. All branch arteries of the stented aorta remained patent.

Conclusion

In this animal model, the novel fibrin-based coated FD showed a similar blood and tissue compatibility as the non-coated FD.

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.

Preoperative Navigated Transcranial Magnetic Stimulation Improves Gross Total Resection Rates in Patients with Motor-Eloquent High-Grade Gliomas: A Matched Cohort Study

BACKGROUND

Navigated transcranial magnetic stimulation (nTMS) is an established, noninvasive tool to preoperatively map the motor cortex. Despite encouraging reports from few academic centers with vast nTMS experience, its value for motor-eloquent brain surgery still requires further exploration.

OBJECTIVE

To further elucidate the role of preoperative nTMS in motor-eloquent brain surgery.

METHODS

Patients who underwent surgery for a motor-eloquent supratentorial glioma or metastasis guided by preoperative nTMS were retrospectively reviewed. The nTMS group (n = 105) was pair-matched to controls (non-nTMS group, n = 105). Gross total resection (GTR) and motor outcome were evaluated. Subgroup analyses including survival analysis for WHO III/IV glioma were performed.

RESULTS

GTR was significantly more frequently achieved in the entire nTMS group compared to the non-nTMS group (P = .02). Motor outcome did not differ (P = .344). Bootstrap analysis confirmed these findings. In the metastases subgroup, GTR rates and motor outcomes were equal. In the WHO III/IV glioma subgroup, however, GTR was achieved more frequently in the nTMS group (72.3%) compared to non-nTMS group (53.2%) (P = .049), whereas motor outcomes did not differ (P = .521). In multivariable Cox-regression analysis, prolonged survival in WHO III/IV glioma was significantly associated with achievement of GTR and younger patient age but not nTMS mapping.

CONCLUSION

Preoperative nTMS improves GTR rates without jeopardizing neurological function. In WHO III/IV glioma surgery, nTMS increases GTR rates that might translate into a beneficial overall survival. The value of nTMS in the setting of a potential survival benefit remains to be determined.

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.

Correction to: In vivo comparison of braided (Accero) and laser-cut intracranial stents (Acclino, Credo): evaluation of vessel responses at subacute and mid-term follow-up in a rabbit model

A Correction to this paper has been published: https://doi.org/10.1007/s10856-021-06518-6

[Acoustic neuromas : Differential diagnoses]

CLINICAL ISSUE

Acoustic neuromas in adults are the most common infratentorial tumors that originate from the Schwann's cells of the vestibular part of the eighth cranial nerve and are clinically noticeable through neurological deficits, such as unilateral hypoacusis, tinnitus, dizziness and unilateral facial nerve palsy. Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI), acoustic neuromas can now be diagnosed with a high rate of sensitivity and specificity; however, there are a number of possible differential diagnoses, such as meningioma, epidermoid and metastases as well as a number of less common diagnoses, such as peripheral nerve sheath tumors, sarcoidosis/neuritis and lipomas, which are sometimes difficult to distinguish from acoustic neuromas. Particularly smaller findings can often only be differentiated with the aid of a histopathological investigation.

PRACTICAL RECOMMENDATIONS

Small intrameatal and asymptomatic acoustic neuromas, some of which are discovered as incidental findings, do not require immediate treatment and should instead be monitored by MRI. Larger findings that are symptomatic and thus cause a number of severe neurological symptoms that are stressful for the patient, should be surgically removed. In cases where surgical treatment is not possible or for smaller symptomatic findings, radiotherapy can also be considered as an alternative.

In vivo comparison of braided (Accero) and laser-cut intracranial stents (Acclino, Credo): evaluation of vessel responses at subacute and mid-term follow-up in a rabbit model

This study aimed to investigate in vivo two stent technologies, with particular emphasis on thrombogenicity and inflammatory vessel remodeling processes. The micro-stents tested in this study were developed for intracranial aneurysm treatment. In our study twelve, New Zealand white rabbits were divided into two groups: 18 laser-cut stents (LCS) and 18 braided stents (BS) were impanated without admiration of antiplatelet medication. Three stents were implanted into each animal in the common carotid artery, subclavian artery, and abdominal aorta. Digital subtraction angiography was performed before and after stent implantation and at follow-up for the visualization of occurring In-stent thromboembolism or stenosis. The Stents were explanted for histopathological examination at two different timepoints, after 3 and 28 days. Angiographically neither in-stent thrombosis nor stenosis for both groups was seen. There was a progressive increase in the vessel diameter, which was more pronounced for BS than for LCS. We detected a higher number of thrombi adherent to the foreign material on day 3 for BS. On day 3, the neointima was absent, whereas the complete formation observed was on day 28. There was no significant difference between both groups regarding the thickness of the neointima. The in vivo model of our study enabled the evaluation of blood and vessel reactions for two different stent technologies. Differences in vessel dimension and tissue around the stents were observed on day 28. Histological analysis on day 3 enabled the assessment of thrombotic reactions, representing an important complementary result in long-term studies.

Utility of Hounsfield unit in the diagnosis of tandem occlusion in acute ischemic stroke

Background

Tandem occlusions can complicate medical and endovascular stroke treatment. To identify these occlusions, computed tomography angiography (CTA) represents the best imaging modality. However, CTA is still not initially performed in some patients not admitted directly to stroke centers. Early identification of an additional occlusion of the proximal extracranial internal carotid artery may improve the best suitable treatment strategy. The purpose of this study was to find a valuable threshold of thrombus attenuation in a non-contrast head CT (NCCT) scan to facilitate a safe diagnosis of tandem occlusions.

Materials and methods

Consecutive patients with acute middle cerebral artery (MCA) occlusions who underwent endovascular treatment were identified from our registry of neuroendovascular interventions. Thrombus attenuations of the affected MCA and contralateral vessel were measured by NCCT. To compare individual baseline blood attenuations, the difference between the thrombus attenuation and the contralateral MCA attenuation (referred to as ΔTM) was calculated.

Results

Three hundred and twenty-five patients were included. There was a highly significant difference between mean thrombus attenuation with isolated MCA occlusion and additional extracranial internal carotid artery (ICA) occlusion (49.9 ± 8 vs. 56.2 ± 10 Hounsfield units (HU); P < 0.001). The area under the receiver operating characteristic curve of ΔTM was 0.72. The optimal threshold value was 13.5 HU, with a sensitivity of 67.5% and a specificity of 68.6%.

Conclusion

Despite a significant difference in thrombus attenuation in MCA occlusions with an additional extracranial ICA occlusion compared with isolated MCA occlusions, a relevant threshold of thrombus attenuation was not found.

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.

[Treatment of intracranial aneurysms with flow diverters]

CLINICAL ISSUE

The clinical picture of a subarachnoid haemorrhage (SAH) is associated with a high morbidity and mortality, due to the associated complications. Therefore, both unruptured and ruptured aneurysms are to be treated based on an individual and interdisciplinary treatment concept. Several endovascular procedures are already available for the treatment of intracranial aneurysms. A more recent concept is the treatment with vessel-reconstructive stents so-called flow diverters.

PRACTICAL RECOMMENDATIONS

Due to the continuous development and revision of flow diverters, the initial complication rates have been significantly reduced, which now effectively and efficiently justifies their clinical use. After careful patient selection and risk-benefit assessment, the implantation of a flow diverter can also be considered for the treatment of ruptured aneurysms and is often the only therapy option in such situations.

[Influence of the "distance to thrombus" in acute middle cerebral artery occlusion : A predictor for the clinical outcome after endovascular treatment]

Hintergrund

Die Therapiestrategie von Patienten mit akutem Schlaganfall der Arteria cerebri media (ACM) wird durch die Lokalisation der Okklusion beeinflusst. Diese Studie zielte darauf ab, die klinischen Ergebnisse bei Patienten mit akutem ischämischem ACM-Verschluss, die mit endovaskulärer mechanischer Thrombektomie (EVT) behandelt wurden, entsprechend dem Okklusionsort zu analysieren.

Methoden

Es wurden 54 Patienten (Alter: 73 ± 15 Jahre; 59 % weiblich), die aufgrund eines akuten ACM-Verschlusses mittels EVT behandelt wurden, eingeschlossen. In koronar reformatierten MIP-Bildern (Maximumintensitätsprojektion) der CT-Angiographie wurde die Distanz zum Thrombus (DT), also dem Abstand vom Karotis‑T zum Beginn des Thrombus, gemessen. Die Korrelation zwischen DT, klinischer Symptomatik und klinischem Outcome der Patienten mit EVT-Therapie wurde analysiert.

Ergebnisse

Die DT korrelierte mit der klinischen Symptomatik, gemessen an der National Institutes of Health Stroke Scale (NIHSS; p = 0,017; R = −0,324), bei Aufnahme. Sie korrelierte auch mit der modifizierten Rankin-Skala nach 90 Tagen (90-Tage-mRS; p = 0,014; R = −0,333). Die DT ist ein Prädiktor für ein gutes klinisches Outcome (mRS nach 90 Tagen) nach EVT; Odds-Ratio: 1,113 (p = 0,02; 95 % Konfidenzintervall [KI] 1,017–1,219). Eine DT >10 mm korrelierte signifikant (p = 0,036) mit einem guten klinischen Outcome (90-Tage-mRS ≤2).

Schlussfolgerung

Die DT korreliert mit der klinischen Symptomatik von Patienten mit akutem ACM-Verschluss. Darüber hinaus sie ein unabhängiger Prädiktor für das klinische Outcome von Patienten, die an einem akuten Schlaganfall durch ACM-Okklusion leiden.

Comparison of PED and FRED flow diverters for posterior circulation aneurysms: a propensity score matched cohort study

BACKGROUND

Flow diversion is a common endovascular treatment for cerebral aneurysms, but studies comparing different types of flow diverters are scarce.

OBJECTIVE

To perform a propensity score matched cohort study comparing the Pipeline Embolization Device (PED) and Flow Redirection Intraluminal Device (FRED) for posterior circulation aneurysms.

METHODS

Consecutive aneurysms of the posterior circulation treated at 25 neurovascular centers with either PED or FRED were collected. Propensity score matching was used to control for age, duration of follow-up imaging, adjunctive coiling, and aneurysm location, size, and morphology; previously ruptured aneurysms were excluded. The two devices were compared for the following outcomes: procedural complications, aneurysm occlusion, and functional outcome.

RESULTS

A total of 375 aneurysms of the posterior circulation were treated in 369 patients. The PED was used in 285 (77.2%) and FRED in 84 (22.8%) procedures. Aneurysms treated with the PED were more commonly fusiform and larger than those treated with FRED. To account for these important differences, propensity score matching was performed resulting in 33 PED and FRED unruptured aneurysm pairs. No differences were found in occlusion status and neurologic thromboembolic or hemorrhagic complications between the two devices. The proportion of patients with favorable functional outcome was higher with FRED (100% vs 87.9%, p=0.04).

CONCLUSION

Comparative analysis of PED and FRED for the treatment of unruptured posterior circulation aneurysms did not identify significant differences in aneurysm occlusion or neurologic complications. Variations in functional outcomes warrant additional investigations.

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.

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 (4 × 15/20 mm and 6 × 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.

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.

The FRED for Cerebral Aneurysms of the Posterior Circulation: A Subgroup Analysis of the EuFRED Registry

BACKGROUND AND PURPOSE

Flow diversion for the posterior circulation remains a promising treatment option for selected posterior circulation aneurysms. The Flow-Redirection Intraluminal Device (FRED) system has not been previously assessed in a large cohort of patients with posterior circulation aneurysms. The purpose of the present study was to assess safety and efficacy of FRED in this location.

MATERIALS AND METHODS

Consecutive patients with posterior circulation aneurysms treated at 8 centers participating in the European FRED study (EuFRED) between April 2012 and January 2019 were retrospectively reviewed. Complication and radiographic and functional outcomes were evaluated.

RESULTS

Eighty-four patients (median age, 54 years) with 84 posterior circulation aneurysms were treated with the FRED. A total of 25 aneurysms (29.8%) had previously ruptured, even though most aneurysms were diagnosed incidentally (45.2%). The intradural vertebral artery was the most common location (50%), and saccular, the most common morphology (40.5%). The median size was 7 mm. There were 8 (9.5%) symptomatic thromboembolic and no hemorrhagic complications. Thromboembolic complications occurred mostly (90.9%) in nonsaccular aneurysms. On last follow-up at a median of 24 months, 78.2% of aneurysms were completely occluded. Functional outcome at a median of 27 months was favorable in 94% of patients. All mortalities occurred in patients with acute subarachnoid hemorrhage and its sequelae.

CONCLUSIONS

The largest cohort of posterior circulation aneurysms treated with the FRED to date demonstrated favorable safety and efficacy profiles of the device for this indication. Treatment in the setting of acute subarachnoid hemorrhage was strongly related to mortality, regardless of whether procedural complications occurred.

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.

Prospective study to assess the tissue response to HPC-coated p48 flow diverter stents compared to uncoated devices in the rabbit carotid artery model

Background

Flow diverters (FDs) are widely used in the treatment of intracranial aneurysms, but the required medication increases the risk of haemorrhagic complications and limits their use in the acute setting. Surface modified FDs may limit the need for dual antiplatelet therapy (DAPT). Hydrophilic polymer coating (HPC) may reduce the need of medication.

Methods

This explorative study, approved by the local authorities and the local welfare committee, compared stent behaviour and overall tissue response between HPC-coated FDs and uncoated FDs, both implanted into the common carotid arteries of eight New Zealand white rabbits. Endothelialisation, inflammatory response, and performance during implantation were assessed. Angiographic follow-up was performed to observe the patency of the devices after implantation and after 30 days. Histological examinations were performed at 30 days to assess foreign body reaction and endothelialisation. Kruskal-Wallis and Wilcoxon tests were used to compare non-parametric variables.

Results

Angiography showed that both coated and uncoated FDs performed well during implantation. All devices remained patent during immediate follow-up and after 30 days. Histopathology showed no significant difference in inflammation within the vessel wall between the two cohorts (2.12 ± 0.75 vs. 1.96 ± 0.79, p = 0.7072). Complete endothelialisation of the stent struts was seen with very similar (0.04 ± 0.02 mm vs. 0.04 ± 0.03 mm, p = 0.892) neoendothelial thickness between the two cohorts after 30 days.

Conclusion

Taking into account the limitation in sample size, non-significant differences between the HPC-coated and uncoated FDs regarding implantation, foreign body response, and endothelialisation were found.

Is there a difference in the grade of degeneration at the cervical spine following anterior cervical fusion with respect to clinical outcome, diagnosis, and repeat procedure? An MRI study of 102 patients with a mean follow-up of 25 years

OBJECTIVE

There is currently no consensus on whether adjacent-segment degeneration (ASD), loss of disc height (DH), and loss of sagittal segmental angle (SSA) are due to anterior cervical discectomy and fusion (ACDF). The purpose of the present study was to assess the grade of segmental degeneration after ACDF and to analyze if there is a difference with respect to clinical outcome, diagnosis, and number of operated levels.

METHODS

A total of 102 patients who underwent ACDF with a minimum follow-up of 18 years were retrospectively identified. At final follow-up, the clinical outcome according to Odom's criteria, the Neck Disability Index (NDI), and reoperation for symptomatic ASD (sASD) was assessed. MRI was performed, and DH, SSA, and the segmental degeneration index (SDI, a 5-step grading system that includes disc signal intensity, anterior and posterior disc protrusion, narrowing of the disc space, and foraminal stenosis) were assessed for evaluation of the 2 adjacent and 4 adjoining segments to the ACDF. MRI findings were compared with respect to clinical outcome (NDI: 0%-20% vs > 20%; Odom's criteria: success vs no success), reoperation for sASD, initial diagnosis (cervical disc herniation [CDH] vs cervical spondylotic myelopathy [CSM] and spondylosis), and the number of operated levels (1 vs 2-4 levels).

RESULTS

The mean follow-up was 25 years (range 18-45 years), and the diagnosis was CDH in 74.5% of patients and CSM/spondylosis in 25.5%. At follow-up, the mean NDI was 12.4% (range 0%-36%), the clinical success rate was 87.3%, and the reoperation rate for sASD was 15.7%. For SDI, no significant differences were seen with respect to NDI, Odom's criteria, and sASD. Patients diagnosed with CDH had significantly more degeneration at the adjacent segments (cranial, p = 0.015; caudal, p = 0.017). Patients with a 2- to 4-level procedure had less degeneration at the caudal adjacent (p = 0.011) and proximal adjoining (p = 0.019) segments. Aside from a significantly lower DH at the proximal cranial adjoining segment in cases of CSM/spondylosis and without clinical success, no further differences were noted. The degree of SSA was not significantly different with respect to clinical outcome.

CONCLUSIONS

No significant differences were seen in the SDI grade and SSA with respect to clinical outcome. The SDI is higher after single-level ACDF and with the diagnosis of CDH. The DH was negligibly different with respect to clinical outcome, diagnosis, and number of operated levels.

Olfactory dysfunction in patients undergoing supraorbital keyhole craniotomy for clipping of unruptured aneurysms

Olfactory performance has rarely been assessed in the perioperative phase of elective aneurysm surgery. Here, we assessed the risk for olfactory deterioration following surgical treatment of unruptured cerebral aneurysm via the supraorbital keyhole craniotomy. A retrospective review of patients with electively treated cerebral aneurysms who underwent perioperative assessment of olfactory function using a sniffin' sticks odor identification test between January 2015 and January 2016 was performed. A subgroup of patients without history of subarachnoid hemorrhage, without prior aneurysm treatment, and confirmed olfactory function underwent supraorbital keyhole craniotomy for aneurysm clipping. Microscopic and endoscopic videos were reviewed for this subgroup. Sixty-four patients who underwent elective aneurysm treatment either via surgical clipping or endovascular aneurysm obliteration were identified. Prior to treatment, 4/64 (6.3%) demonstrated bilateral anosmia. Collectively, 14 patients (21.9%) met subgroup criteria of supraorbital keyhole craniotomy for aneurysm clipping. Here, olfactory performance significantly decreased postoperatively on the side of craniotomy (ipsilateral, P = 0.007), whereas contralateral and bilateral olfactory function remained unaltered (P = 0.301 and P = 0.582, respectively). Consequently, 4/14 patients (28.6%) demonstrated ipsilateral anosmia 3 months after surgery. One patient (1/14, 7.1%) also experienced contralateral anosmia resulting in bilateral anosmia. Intraoperative visualization of the olfactory tract and surgical maneuvers do not facilitate prediction of olfactory outcome. The supraorbital keyhole craniotomy harbors a specific risk for unilateral olfactory deterioration. Lack of perioperative olfactory assessment likely results in underestimation of the risk for olfactory decline. Despite uneventful surgery, prediction of postoperative olfactory function and dysfunction remain challenging. Clin. Anat. 33:316-323, 2020. © 2019 Wiley Periodicals, Inc.

Intravenous versus intra-arterial digital subtraction angiography: Occlusion rate and complication assessment of experimental aneurysms after flow diverter treatment in rabbits

PURPOSE

Conventional intra-arterial digital subtraction angiography, which requires surgical exposure and ligation of the femoral or carotid artery, is a limited method of evaluating elastase-induced aneurysms in New Zealand white rabbits. The purpose of this study was to assess aneurysm morphology, occlusion rates and complications after flow diverter treatment comparing intravenous and intra-arterial digital subtraction angiography.

METHODS

We previously published a preclinical study in which we evaluated the occlusion rates of elastase-induced aneurysms after treatment with a prototype flow diverter, by using intra-arterial digital subtraction angiography at three months ( n = 9) and six months ( n = 9). In addition to that intravenous digital subtraction angiography before treatment, after one month (early follow-up group) and after three months (late follow-up group) was performed. Occlusion rates were compared within the two groups by means of residual contrast filling.

RESULTS

Baseline aneurysm characteristics revealed no significant differences between intra-arterial digital subtraction angiography and intravenous digital subtraction angiography. Aneurysm occlusion rates in both follow-up groups using intravenous digital subtraction angiography were significantly higher compared to intra-arterial digital subtraction angiography (early follow-up group: intravenous digital subtraction angiography (one month) versus intra-arterial digital subtraction angiography (three months); p = 0.03 and late follow-up group: intravenous digital subtraction angiography (three months) versus intra-arterial digital subtraction angiography (six months); p = 0.04). Intravenous digital subtraction angiography is feasible to detect and reproduce device occlusions, in-stent stenosis and post-stent stenosis.

CONCLUSION

Intravenous digital subtraction angiography can not give a sufficient statement on the aneurysm occlusion process compared to intra-arterial digital subtraction angiography and is therefore not recommended for imaging follow-up after flow diverter treatment in rabbits. Regarding untreated aneurysms and complications like device occlusions, in-stent stenosis and post-stent stenosis intravenous digital subtraction angiography proofed to be a good alternative to intra-arterial digital subtraction angiography in our study.

Is there an impact of cervical plating on the development of adjacent segment degeneration following Smith-Robinson procedure? A magnetic resonance imaging study of 84 patients with a 24-year follow-up

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) without and with cervical plating (ACDF+CP) are accepted surgical techniques for the treatment of degenerative cervical disc disorders. The effect of CP on the development of adjacent segment degeneration (ASD) remains unclear.

PURPOSE

To assess whether CP accelerates the degeneration of the adjacent and adjoining segments.

STUDY DESIGN/SETTING

This is an imaging cohort study.

PATIENT SAMPLE

Retrospectively, a total of 84 patients who underwent ACDF or ACDF+CP were identified. At final follow-up, an MRI was performed and evaluated in this study.

MATERIALS AND METHODS

An MRI of 84 patients who underwent ACDF (46 patients) and ACDF+PS (38 patients) was performed. The mean follow-up was 24 years (17-45 years). None of the patients had a repeat procedure in the cervical spine. The grade of degeneration of the segments adjacent and adjoining to the fusion was assessed via a five-step grading system (segmental degeneration index, or SDI) that includes disc signal intensity, anterior and posterior disc protrusion, narrowing of the disc space, and foraminal stenosis. Furthermore, the disc height (DH) and sagittal segmental angle (SSA) of fused segments were measured.

RESULTS

A significantly (p<.001) greater SDI was identified at the caudal adjacent segment following ACDF compared to ACDF+CP. No other significant differences were identified in patients following ACDF and ACDF+CP. Between 50% and 96% of all segments showed severe degenerative changes according to SDI. There was no significant difference in DH between the patients following ACDF and ACDF+CP. The SSA in patients who underwent ACDF+CP was significantly greater than in the ACDF patients (p=.002).

CONCLUSIONS

In this cohort of patients, cervical plating had no significant impact on segmental degeneration and decrease of DH in the adjacent and adjoining segments. ACDF+CP seem to preserve the lordotic alignment more with respect to the SSA than ACDF.

[White matter alterations after chemotherapy and radiation]

Nowadays chemotherapy and radiotherapy are fundamental therapy concepts in the guidelines of malignant tumors of the central nervous system. Both therapy concepts can cause neurological symptoms or white matter alterations can occur, which can be classified into acute, subacute and chronic. Both symptoms and white matter alterations during acute and subacute phases are in most cases completely reversible, whereas chronic white matter alterations can lead to severe neurological limitations and further impair the quality of life of cancer patients.

Transient in-stent stenosis: a common finding after flow diverter implantation

Background and purpose

In recent years, implantation of flow diverters has emerged as an option for the endovascular treatment of intracranial aneurysms. One complication of treatment with flow diverters is the occurrence of in-stent stenosis, which has been reported to be partially reversible. The purpose of our study was to assess the incidence and dynamics of in-stent stenosis on angiographic short term and long term follow-up after treatment with flow diverters.

Methods

A retrospective review of our prospectively maintained database identified all patients with intracranial internal carotid artery (ICA) aneurysms treated by flow diverters at our institution between 2014 and 2017. Clinical charts, procedural data, and angiographic results were reviewed.

Results

18 patients were included. The mean short term follow-up was 92±19 days and mean long term follow-up was 449±120 days after treatment. No neurologic complications were observed. There was no procedure related mortality. Long term angiographic results showed complete occlusion in 83.3%, neck remnants in 11.1%, and incomplete occlusion in 5.5% of cases. In-stent stenosis was observed in all cases. Mean stenosis improved significantly from 30% on short term follow-up to 12% on long-term follow-up (P<0.0001).

Conclusion

In-stent stenosis is a common finding on short term follow-up after the treatment with flow diverters but improves over time.

Acute Occlusions of Dual-Layer Carotid Stents After Endovascular Emergency Treatment of Tandem Lesions

BACKGROUND AND PURPOSE

A new generation of carotid artery stents that uses a second micromesh layer to reduce embolic events during carotid artery stenting has recently been introduced. The purpose of this study was to compare acute occlusion rates of these new dual-layer stents with those of single-layer stents in the setting of emergency carotid artery stenting with intracranial mechanical thrombectomy in acute ischemic stroke.

METHODS

Consecutive patients with acute tandem (intra- and extracranial) lesions of the anterior circulation who were endovascularly treated at our institution were identified from our registry of neuroendovascular interventions. Clinical, angiographic, and neuroimaging data were analyzed. End points included acute occlusions of the carotid stents (within 72 hours after stenting) and symptomatic intracerebral hemorrhage.

RESULTS

Forty-seven patients were included. Dual-layer stents (n=20) had a significantly higher rate of acute occlusions than single-layer stents (n=27; 45% versus 3.7%; P=0.001; odds ratio, 21.3; 95% confidence interval, 2.4-188.4). There were no significant differences in the rates of patients who had any antiplatelet or dual antiplatelet medication before admission, in the rates of postinterventional symptomatic intracerebral hemorrhage, the mean National Institutes of Health Stroke Scale scores at admission, or the modified Rankin Scale scores at discharge.

CONCLUSIONS

The recently introduced dual-layer stents have a higher risk of acute occlusion compared with single-layer stents in the treatment of acute stroke.

Adjacent Segment Degeneration After Anterior Cervical Discectomy and Fusion With an Autologous Iliac Crest Graft: A Magnetic Resonance Imaging Study of 59 Patients With a Mean Follow-up of 27 Years

BACKGROUND

Anterior cervical decompression and fusion (ACDF) is a widely accepted surgical technique for the treatment of degenerative disc disease. ACDF is associated with adjacent segment degeneration (ASD).

OBJECTIVE

To assess whether physiological aging of the spine would overcome ASD by comparing adjacent to adjoining segments more than 18 yr after ACDF.

METHODS

Magnetic resonance imaging of 59 (36 male, 23 female) patients who underwent ACDF was performed to assess degeneration. The mean follow-up was 27 yr (18-45 yr). Besides measuring the disc height, a 5-step grading system (segmental degeneration index [SDI]) including disc signal intensity, anterior and posterior disc protrusion, narrowing of the disc space, and foraminal stenosis was used to assess the grade of adjacent and adjoining segments.

RESULTS

The SDI of cranial and caudal adjacent segments was significantly higher compared to adjoining segments (P &lt; .001). The disc height of cranial and caudal adjacent segments was significantly lower compared to adjoining segments (P &lt; .001, P &lt; .01). The SDI of adjacent segments in patients with repeat cervical procedure was significantly higher than in patients without repeat procedure (P = .02, P = .01). The disc height of the cranial adjacent segments in patients with repeat procedure was significantly lower than in patients without repeat procedure (P = .01).

CONCLUSION

The physiological aging of the cervical spine does not overcome ASD. The disc height and the SDI in adjacent segment are significantly worse compared to adjoining segments. Patients who underwent repeat procedure had even worse findings of disc height and SDI.

The Barrel stent: new treatment option for stent-assisted coiling of wide-necked bifurcation aneurysms—results of a single-center study

Purpose

The Barrel stent is a laser cut stent designed for stent-assisted coil embolization of wide-necked bifurcation or branch aneurysms with a single device, with the purpose of lowering the metal-to-artery ratio and its inherent risk of thromboembolic complications of multiple stents. We report our early experiences with this device in 17 patients in this retrospective single-center analysis.

Materials and methods

17 consecutive patients who underwent stent-assisted coil embolization of wide-necked bifurcation aneurysms with the Barrel stent were retrospectively identified. We analyzed the feasibility of successful deployment and post-treatment angiographic results. Adverse events, clinical outcome, and angiographic follow-up results were also analyzed.

Results

Aneurysms were located in the internal carotid artery (n=3), the middle cerebral artery (n=9), the anterior communicating artery (n=3), and the basilar artery (n=2). In the immediate post-treatment angiography, adequate occlusion (neck remnant or total occlusion) was observed in 16/17 (94.1%) of aneurysms. One patient experienced a transient ischemic attack. No permanent neurologic deficits were observed. 13/17 (76.5%) patients underwent short-term follow-up angiography after 3 months, all of which showed adequate occlusion of the aneurysm.

Conclusions

In this small retrospective single-center analysis we show that stent-assisted coiling with the Barrel stent is a safe and effective option for the endovascular treatment of intracranial wide-necked bifurcation aneurysms.

Neurocognitive Function Surrounding the Resection of Frontal WHO Grade I Meningiomas: A Prospective Matched-Control Study

OBJECTIVE

Patients with intracranial meningiomas can experience neurocognitive dysfunctions in specific cognitive domains depending on tumor location and size. The literature regarding cognitive function surrounding the resection of frontal meningiomas is sparse.

METHODS

We performed a prospective matched-control study to investigate the cognitive performance of frontal meningioma patients undergoing resection. The neurocognitive status 1 week and 2 months after resection was compared with the preoperative status and matched-controls. Matching was performed for age, sex, handedness, education, and profession. An extensive test battery was used to assess perceptual speed, executive function, visual-spatial and verbal working memory, short- and long-term memory, verbal fluency, fluid intelligence, anxiety, and depression.

RESULTS

Twelve patients with frontal World Health Organization grade I meningioma and 12 matched-controls underwent cognitive testing. Macroscopically, complete removal was achieved in all cases. Comparison of patients and controls revealed significant cognitive impairments in perceptual speed, executive function, short-term memory, and verbal fluency preoperatively and postoperatively. At 2 months' follow-up, perceptual speed and verbal fluency were still significantly impaired, whereas executive function and short-term memory were equal to that in the control group. None of the patients experienced cognitive deterioration after surgical therapy.

CONCLUSION

Patients with frontal meningiomas display preoperative and postoperative deficits in perceptual speed, executive function, short-term memory, and verbal fluency. The risk for cognitive deterioration owing to surgical resection is low. Within the first two months after surgery, executive function and short-term memory appear to recover.

Superficial Siderosis after Germinal Matrix Hemorrhage

BACKGROUND AND PURPOSE

Germinal matrix hemorrhage is a frequent complication of prematurity and can be associated with adverse neurodevelopmental outcome, depending on its severity. In addition to parenchymal damage, intraventricular residues of hemorrhage and hydrocephalus MR imaging findings include superficial siderosis. The purpose of this study was to investigate the prevalence and location of superficial siderosis in patients with a history of germinal matrix hemorrhage.

MATERIALS AND METHODS

We retrospectively identified patients with a history of germinal matrix hemorrhage who underwent MR imaging in our institution between 2008 and 2016. Imaging was evaluated for the presence and location of superficial siderosis. The presence of subependymal siderosis and evidence of hydrocephalus were assessed.

RESULTS

Thirty-seven patients with a history of germinal matrix hemorrhage were included; 86.5% had preterm births. The mean age at the first MR imaging was 386 days (range 2-5140 days). The prevalence of superficial siderosis was 67.6%. Superficial siderosis was detected significantly more often when MR imaging was performed within the first year of life (82.8% versus 12.5%, P < .000). When present, superficial siderosis was located infratentorially in all cases, while additional supratentorial superficial siderosis was detectable in 27%.

CONCLUSIONS

Here we report that superficial siderosis is a common MR imaging finding in the first year of life of patients with a history of germinal matrix hemorrhage, but it dissolves and has a low prevalence thereafter. A prospective analysis of its initial severity and speed of dissolution during this first year might add to our understanding of the pathophysiology of neurodevelopmental impairment after germinal matrix hemorrhages.

[Degenerative and age-related alterations of the spine]

Degenerative alterations of the spine occur in an individual-specific manner with increasing age. This is not only dependent on external factors, such as hard physical labor over many years but can also be genetically influenced as demonstrated in recent studies. The spinal cord is well-protected within the spinal canal but can be impaired by degenerative alterations of the intervertebral discs and functional spinal segments. Depositions or narrowing of nerve structures can cause lasting pain or focal neurological deficits, such as paralysis or sensitivity disorders. These complaints can slowly develop over years, e.g. by a gradually increasing bony narrowing of the spinal canal (spinal canal stenosis) or can occur suddenly, e.g. an acute herniated disc. However, low back pain is much more common and occurs in approximately 80 % of people sometime during their lifetime. It is necessary to recognize the normal age-related anatomical alterations in magnetic resonance imaging (MRI), particularly for intervertebral discs in order to interpret these correctly. Knowledge of the spectrum of the various age-related degenerative processes which can occur in intervertebral discs and vertebral bodies is necessary to be able to differentiate them from pathological alterations. This is important because therapy decisions are often made as a direct result of MRI.

[Germ cell and embryonal tumors]

Germ cell tumors, which constitute approximately 3-5% of tumors of the central nervous system (CNS), can be subdivided into germinomas, embryonal carcinomas, yolk sac tumors, choriocarcinomas, teratomas and mixed germ cell tumors. The diagnosis of intracranial germ cell tumor is based on the clinical symptoms, detection of tumor markers, such as alpha fetoprotein (AFP) and the beta subunit of human chorionic gonadotropin (beta-hCG) in blood and cerebrospinal fluid (CSF), magnetic resonance imaging (MRI) of the brain and spinal cord, CSF cytology and histology. The diagnosis of a secreting germ cell tumor, i.e. a non-germinoma, can be made by the determination of AFP and hCG as tumor markers. Germinomas are radiosensitive but are equally as sensitive to chemotherapy. Teratomas of the CNS are mostly diagnosed in newborns and infants. The most decisive role in the treatment of teratomas is played by as complete a resection as possible. Chemotherapy and irradiation play a subordinate role.Embryonal tumors, which constitute approximately 15-20% of CNS tumors, include medulloblastomas, primitive neuroectodermal tumors (PNET) of the CNS and the atypical teratoid rhabdoid tumor of the CNS. Medulloblastoma is the most common malignant brain tumor in childhood and adolescence. The incidence peak is the fifth year of life with a male predisposition in a ratio of 1.5:1. Medulloblastomas constitute 12-25% of all pediatric CNS tumors and 30-40% of pediatric tumors of the posterior cranial fossa. At the time of diagnosis evidence of dissemination in the CSF cavity is found in approximately 40% of patients. The extreme cell density makes medulloblastomas hyperdense in computed tomography (CT) and can therefore be differentiated from hypodense astrocytomas. The PNETs are histologically related to medulloblastomas, pineoblastomas, atypical teratoid rhabdoid tumors and peripheral neuroblastomas. They are relatively rare in children constituting less than 5% of supratentorial neoplasms. Patients are mostly clinically conspicuous due to macrocephalus and signs of brain pressure and/or seizures. In native CT the solid components of PNETs show a hyperdensity compared to the surrounding brain parenchyma probably due to the high cell density. Cysts and calcification are often detectable. The survival rate of children with CNS tumors has continuously increased in recent years. When corresponding clinical symptoms appear, such as headache, nausea or vomiting when fasting, all of which are evidence of increased intracranial pressure, MRI should be carried out as quickly as possible. Children should be treated in centers with departments of pediatric oncology and hematology and within the framework of studies.

Carotid Elongation Does Not Affect Angiographic Results of Mechanical Thrombectomy in Acute Stroke

BACKGROUND AND PURPOSE

New techniques have substantially raised recanalization rates of mechanical thrombectomy in acute ischemic stroke in the last few years with initial prospective trials reporting good neurological outcome in up to 58 % of the cases. However some recent reports questioning the benefit of endovascular therapy have initiated a discussion about the importance of patient-selection. The purpose of this study was to investigate whether an elongation of the carotid artery affects the angiographic outcome of the recanalization procedure in middle cerebral artery (MCA)-occlusions.

MATERIALS AND METHODS

The data of 54 patients with occlusions of the M1-segment who underwent mechanical thrombectomy were included. The lengths of the carotid arteries were measured using preinterventional computed tomography (CT)-angiograms. To take individual patient's height into account these lengths were divided by the length of the spine from the tip of the dens to the bottom of the th3 vertebral body (referred to as carotid-to-spine (CS)-Ratio). Angiographic results were scored according to the modified thrombolysis in cerebral infarction (mTICI)-score.

RESULTS

Recanalization with mTICI ≥ 2b was achieved in 83.3 %. The mean CS-Ratio was 1.32 ± 0.13. There was a significant correlation between the CS-Ratio and the age of the patients. There were no significant differences in the CS-Ratios of occlusions that were successfully recanalized and those that were not. Neither were there significant correlations of the CS-Ratio and the length of procedure or the number of deployments of the stentretrievers.

CONCLUSION

In this retrospective analysis we report that carotid elongation does not affect angiographic results of mechanical thrombectomy in acute stroke.

Peri-interventional Subarachnoid Hemorrhage During Mechanical Thrombectomy with stent retrievers in Acute Stroke: A Retrospective Case-Control Study

BACKGROUND

Mechanical thrombectomy with stent retrievers in acute stroke has emerged as a promising new technique with the highest recanalization rate of the therapeutic procedures available so far. However, endovascular treatment is also associated with the risk of specific complications. One of those is the occurrence of peri-interventional subarachnoid hemorrhage (SAH), which has been reported in 5-16 % of the cases. Interestingly, this rate is higher than that of angiographically detectable perforations (0-3 %), leaving the majority of peri-interventional SAH to be due to angiographically occult perforations. Little is known about the influence of this finding on clinical outcome. The purpose of this study was to investigate the clinical relevance of SAH due to occult perforations during thrombectomy with stent retrievers.

METHODS

Postinterventional computed tomography (CT) scans of 217 consecutive patients with acute occlusions of intracerebral arteries who were treated with stent retrievers in our department between October 2009 and October 2012 were retrospectively analyzed.

RESULTS

SAH was found on postinterventional CT scans in 5.5 % of the cases. Seven cases were included for further analysis and matched to controls by the following characteristics: (1) site of occlusion, (2) result of the recanalization procedure according to the modified thrombolysis in cerebral infarction score, (3) administration of intravenous recombinant tissue plasminogen activator, (4) presence of proximal extracranial occlusion, (5) age, and (6) sex. Comparison of the angiographic data of the two cohorts showed no significant difference in the length of the procedures or the number of maneuvers needed for recanalization, nor were there significant differences in clinical outcomes as measured by NIHSS and mRS scores. Secondary symptomatic ICH occurred in one case in either cohort and led to death in both cases. The rate of asymptomatic ICH within the first 24 h after recanalization was significantly higher in the group with peri-interventional SAH (57 vs. 0 %, P = 0.018).

CONCLUSIONS

This small retrospective case-control study did not reveal a significant influence of peri-interventional SAH due to angiographically occult perforations on neurologic outcome of patients treated with stent retrievers.

Evaluation of a newly designed flow diverter for the treatment of intracranial aneurysms in an elastase-induced aneurysm model, in New Zealand white rabbits

INTRODUCTION

In this study, we analyzed angiographic and histologic aneurysm occlusion of a newly designed flow-diverting device. Visibility and flexibility, as well as occlusions of side branches and neointimal proliferation were also evaluated.

METHODS

Aneurysms were induced in 18 New Zealand white rabbits and treated with a braided, "closed-loop-designed" device of nitinol. Additional devices were implanted in the abdominal aorta to cover the origin of branch arteries. Angiographic follow-ups were performed immediately after placement of the device, after 3 months (n = 9) and 6 months (n = 9). The status of aneurysm occlusion (using a five-point scale) and the patency of branch arteries were assessed.

RESULTS

Aneurysm occlusion rates were noted as grade 0 in 2 (11 %), grade I in 1 (6 %), grade II in 1 (6 %), grade III in 9 (50 %), and grade IV in 5 (28 %) of 18 aneurysms, respectively, indicating a complete or near-complete occlusion of 78 % under double antiplatelet therapy. Aneurysm occlusion was significantly higher at 6 months follow-up (P = 0.025). Radiopaque markers provided excellent visibility. Limited device flexibility led to incomplete aneurysm neck coverage and grade 0 occlusion rates in two cases. Distal device occlusions were found in three cases, most likely due to an extremely undersized vessel diameter in the subclavian artery. No case of branch artery occlusion was seen. Intimal proliferation and diameter stenosis were moderate.

CONCLUSION

The tested flow diverter achieved near-complete and complete aneurysm occlusion under double antiplatelet therapy of elastase-induced aneurysms in 78 %, while preserving branch arteries.