Long-term results of wide-necked intracranial bifurcation aneurysms treated with stent-assisted coiling using low-profile acandis acclino stents.

PURPOSE: Little data exists on endovascular treatment of complex intracranial aneurysms with the Acandis Acclino low-profile self-expanding closed-cell stent systems and is mainly limited to short- or midterm results. We report our long-term, single-centre experience with three generations of Acclino stents treating complex intracranial aneurysms. METHODS: 62 wide-necked intracranial aneurysms were treated electively using 88 Acclino stent systems. Single stent-assisted coiling was the preferred treatment in 38 cases and the kissing-Y stenting technique in 24 cases. We analysed demographic data and long-term follow-up results. RESULTS: All stents were successfully deployed with immediate complete (Raymond Roy occlusion classification, RROC I) or near-complete occlusion (RROC II) achieved in 93,5%. Follow-up was available in 55 cases with a mean follow-up of 36 months (range 9-80 months). Long-term RROC I or II was achieved in 49 cases (89,1%). Three cases of stable residual aneurysmal filling were observed (5,5%). Seven aneurysms (12,7%) demonstrated a worsening on follow-up leading either to a neck remnant (4 cases, 7,3%) or to an aneurysm recurrence (3 cases, 5,5%). One recurrent aneurysm was retreated with coilembolization (1,8%). The directly procedural-related complication rate was 4,8%. Seven cases of clinically silent in-stent stenosis (12,7%; morbidity n = 0) were detected on long-term follow-up, six of them using the kissing-Y stenting technique. CONCLUSION: Endovascular treatment of various intracranial aneurysms using the Acandis Acclino stent systems is safe and efficient with high aneurysm occlusion rates combined with low complication rates on long-term follow-up. Overall, rates of in-stent stenosis are low but may depend on the treatment technique (single stent-assisted coiling versus kissing-Y stenting with coiling).

Endovascular treatment of distal medium vessel occlusions using microcatheter aspiration thrombectomy.

BACKGROUND AND PURPOSE: Recent studies suggest that endovascular treatment (EVT) in distal medium vessel occlusion (DMVO) stroke is beneficial even beyond middle cerebral artery (MCA) - M2 segment. However, data about aspiration thrombectomy of DMVOs is scarce since common state-of-the-art aspiration catheters are usually too large for small distal intracranial arteries. We report our initial experiences using the microcatheter aspiration thrombectomy (MAT) technique as frontline therapy for acute DMVOs in the MCA territory. METHODS: We retrospectively analyzed all acute ischemic stroke (AIS) patients that underwent MAT of a primary or secondary DMVO in the M3 or M4 segment between January 2019 and October 2021. Recanalization rates, procedural safety and outcome data were recorded. RESULTS: MAT of acute M3 and M4 occlusions was performed in 19 patients with AIS. Six had isolated DMVO strokes, 13 had secondary DMVOs during EVT of a proximal large vessel occlusion. Successful revascularization to DMVO TICI ≥ 2b was achieved in 58% (11/19) with a single pass in all of them. The median National Institutes of Health Strokes Scale (NIHSS) score at admission and discharge was 12 and 3, respectively. 68% (13/19) of the patients had a good clinical outcome at discharge (modified Rankin Scale 0-2). No symptomatic complications related to MAT occurred. CONCLUSIONS: MAT of DMVOs in the MCA territory is technically feasible and effective. Compared to stent retriever-based thrombectomy in DMVOs the hemorrhagic complication rate appears notably lower. Further studies are needed to validate the benefit of mechanical thrombectomy in the distal intracranial vasculature.

Thin Slice Unenhanced Brain CT Can Detect Aneurysms Larger than 7 mm.

Purpose: To evaluate the detection rate of intracranial aneurysms on reconstructed thin slice non enhanced CT (NECT) scans. Methods: NECT scans from 34 patients with 35 aneurysms and 35 individuals without aneurysms were collected. Thin slice maximum intensity projections of the NECT scans were reconstructed. One observer evaluated the native images twice with a time interval of six month between both passes with respect to the prevalence and location of an aneurysm. The size and location of the aneurysms were evaluated in corresponding CT-Angiography and Time of flight datasets. A logit regression analysis was performed with size and location as dependent variables. 2 × 2 tables were constructed. The sensitivity and false negative rate were calculated for aneurysms with 0-6.9 mm, 7-9.9 mm and 10-20 mm and the under the curve (AUC) was calculated. Results: The overall detection rate of the aneurysms was 63% for the first pass and 66% for the second pass in the reconstructed NECT scans. The detection rate of aneurysms is size dependent. The sensitivity to detect aneurysms with a size of 0-6.9 mm was 0.09 and 0.03, for aneurysms with a size of 7-9.9. mm was 0.8 and 0.7 and for aneurysms with a size of 10-20 mm was 0.92 for both passes.The AUC was 0.77 for the first pass and 0.78 for the second pass. Conclusions: NECT scans can be used to detect a significant proportion of intracranial aneurysms larger than 7 mm if properly displayed and reconstructed. These patients should receive further vascular imaging to prevent future aneurysm related subarachnoid hemorrhage.

Mechanical thrombectomy of M2 occlusions with distal access catheters using ADAPT.

BACKGROUND AND PURPOSE: The direct aspiration first pass technique (ADAPT) using distal access catheters (DAC) has proven to be an effective and safe endovascular treatment strategy of acute ischemic stroke with large vessel occlusions (LVO). However, data about direct aspiration using DAC in M2 segment occlusions is limited. We assess the safety and efficacy of DACs in acute M2 occlusions using ADAPT with large bore (5 French /6 French) aspiration catheters as the primary method for endovascular recanalization. MATERIALS AND METHODS: From January 2017 to July 2018, 52 patients with an acute ischemic stroke due to M2 occlusions underwent mechanical thrombectomy using ADAPT with DACs (SOFIA 5 French/Catalyst 6) as frontline therapy. Patient demographics, technical parameters and outcome data were recorded. RESULTS: Median National Institutes of Health Strokes Scale (NIHSS) Score was 12 at admission. Successful revascularization to mTICI 2b-3 with ADAPT alone was achieved in 45 of 52 patients (86.5%) with mTICI 3 achieved in 32 patients (61.5%). Additional stent retrievers were used in 6 patients and led to an overall successful revascularisation of 92.3% (48/52). Median NIHSS at discharge was 4. 29 of 52 (55.8%) patients had a modified Rankin Scale (mRS) Score 0-2 at three months. Symptomatic intracranial hemorrhage did not occur. CONCLUSION: DACs can safely be used for mechanical thrombectomy of acute M2 occlusions by the ADAPT approach. Their use alone can be a high efficacious treatment of distal intracranial thromboembolic occlusions.

Delayed and incomplete treatment may result in dural fistula development in children with Vein of Galen malformation.

The association of dural arteriovenous fistulas (DAVF) in children with Vein of Galen malformation (VGM) has recently been reported for the first time. In a larger series of cases treated with transarterial NBCA embolization, 30% had DAVF. We wanted to analyze the development of DAVF in our cohort of children with VGM and to evaluate whether their occurrence depends on different treatment timing and embolic materials. We analyzed 43 VGM cases treated with a combined transarterial and transvenous approach between 2003 and 2016. In our early series until 2011, we used coils solely in 21 children. Since 2012, 22 children were treated with the combination of coils and Onyx. In the early series treated with coils solely, no case presented initially with or developed DAVF over time on follow-up angiograms. In our recent series we found four cases (9%) with DAVF. In two patients (5%), DAVF were found on the initial angiogram. Both patients presented at our department at age >2 years and were not treated elsewhere before. One patient (2%) presented at our department with too proximal occlusion of arterial feeders performed at another institution before. Only one patient (2%) developed DAVF in our department after the transarterial use of Onyx. Interestingly, this child did not develop DAVF as long as we used coils solely and his DAVF was localized exactly where an Onyx cast was identified. In conclusion, delayed and incomplete treatment may have a considerable impact on the occurrence of DAVF in VGM.

Endovascular treatment of head and neck arteriovenous malformations: long-term angiographic and quality of life results.

AIM: To present the long-term angiographic and subjective results of patients with head and neck arteriovenous malformations (HNAVMs) after endovascular treatment. METHODS: We retrospectively analyzed the medical files of 14 patients with HNAVM who were treated between 2000 and 2014. The treatment of choice was a transarterial superselective microcatheter-based approach followed by embolization using liquid embolic agents. The patients were asked to answer a quality of life questionnaire about the following symptoms before and after treatment: pain, functional impairment, cosmetic deformity, impairment in daily life, and bleeding. RESULTS: Complete or >90% closure of the AVM was achieved in 6 of 14 patients (43%). >50% shunt reduction was achieved in 10 patients (71%). Three complications were encountered in a total of 86 interventional procedures. Six patients presented with bleeding which was cured in all cases (100%). Four of the 14 patients (29%) specified pain which was resolved in two of them. Another six patients (43%) presented with functional impairment; four were cured and two noted an improvement. All 14 patients presented with cosmetic concerns; four were cured and eight experienced a clearly visible improvement. Nine of 13 patients (69%) presented with impairment in daily life which was resolved in five patients and four reported an improvement. CONCLUSIONS: Endovascular embolization is a well-tolerated therapy for HNAVM with a low complication rate. Good angiographic results, positive subjective results, and improvement in different aspects of quality of life can be achieved.

Endovascular treatment of complex intracranial aneurysms using Acandis Acclino stents.

OBJECTIVE: To determine the safety and effectiveness of a new low-profile, laser-cut, closed-cell stent system in the treatment of complex intracranial aneurysms. METHODS: A total number of 43 patients with complex intracranial aneurysms were treated using 60 Acandis Acclino stent systems (follow-up 2012-2016; mean 11 months). 36 patients presented with wide-necked intracranial aneurysms, dissecting aneurysms were seen in 7 patients. 39 patients received stent-assisted coiling. We analyzed demographic data and follow-up results. RESULTS: Sixty stents were successfully deployed. In one paraophthalmic internal carotid artery aneurysm the stent could not be placed. Thirty-three wide necked aneurysms were treated by single or multiple stent-assisted coiling. Complete occlusion was achieved in 31 of those cases (94% Raymond-Roy occlusion classification, RROC 1). Two patients showed stable residual aneurysmal filling (RROC 3). In three wide-necked aneurysms, sole stenting was the preferred treatment. For dual stent-assisted procedures the kissing-Y stenting technique was successfully performed in 11 aneurysms. In all dissecting aneurysms constructive therapy with stenting and preservation of the affected parent artery was achieved. Additional subsequent coil embolization was intentionally planned and successfully performed in 6 of the 7 dissecting aneurysms. The overall directly procedure-related complication rate was 7%, including one death. CONCLUSIONS: Endovascular treatment of complex intracranial aneurysms using Acclino stents is a feasible and safe procedure with low complication rates. Even severe cases can be treated among others using the kissing-Y stenting technique, with good mid-term results.

Fistulous-type vein of Galen malformation phantom model for endovascular training and research.

INTRODUCTION: Vein of Galen malformation (VGM), a high-flow intracranial arteriovenous shunt, is among the most severe neurovascular diseases in childhood. In many cases untreated children die or survive only severely disabled. Endovascular embolization is the preferred treatment. OBJECTIVE: To develop a simple fistulous-type VGM phantom model for teaching and training of different endovascular treatment methods and to investigate new treatment options and devices. METHODS: An experimental in vitro pulsatile phantom model was developed imitating a high-flow fistulous-type VGM, which is typical, especially in the neonatal phase. Pressure measurements at different arterial sites were performed before and after closure of the VGM. Closure of the VGM was achieved by coiling using a combined microcatheter-based transvenous and transarterial approach called 'kissing microcatheter technique'. RESULTS: The behaviour of the phantom model in vitro under fluoroscopy and under angiographic runs was extremely similar to that in in vivo conditions in children. The results showed that intra-arterial pressures changed and increased statistically significantly at all measurement sites after embolization, as in human arteriovenous malformation. We also demonstrated different and complementary visualizations of hemodynamics and angioarchitecture by antegrade and retrograde microcatheter injections. CONCLUSIONS: Our phantom model behaves like a typical fistulous-type VGM and can be used in vitro for teaching and training and for further research. It offers a new and better understanding of hemodynamics and angioarchitecture in the endovascular management of VGM.

Vascular angular remodeling by kissing-Y stenting in wide necked intracranial bifurcation aneurysms.

INTRODUCTION: Single stent deployment leads to a change in vascular geometry in wide necked bifurcation aneurysms. In some complex cases, the use of the single stent technique might not be sufficient or may not be feasible. The kissing-Y stenting technique appears to be an alternative endovascular treatment option. The aim of this study was to evaluate the effects of the kissing-Y stenting technique on vascular angular remodeling. METHODS: 21 patients with wide necked intracranial bifurcation aneurysms at different sites (10 anterior communicating artery, 6 middle cerebral artery, 3 basilar artery, 1 vertebral artery/posterior inferior cerebellar artery, 1 internal carotid artery/posterior communicating artery) were treated with 44 closed cell stents (follow-up 2012-2016) using the kissing-Y stenting technique. We analyzed vascular angle geometry between the mother and both affected daughter vessels by digital subtraction angiography, before and after stent deployment, using standard working projections. RESULTS: Endovascular treatment of wide necked intracranial aneurysms using the kissing-Y stenting technique significantly decreased the angle between the bifurcation branches from 130.4±9.5° to 91.5±9.1° (p<0.0001). CONCLUSIONS: Kissing-Y stenting in wide necked bifurcation aneurysms leads to vascular angular remodeling of both affected branches. The resulting straightening of the bifurcation angle may prevent aneurysmal recurrence.

Hydrocephalus in vein of Galen malformation: etiologies and therapeutic management implications.

BACKGROUND: Up to now, only little is known about hydrocephalus (HC) in vein of Galen malformation (VGM). We want to present the different etiologies and our long-term experience (1992-2015) in the management of HC. METHODS: Out of 44 treated children with VGM, we retrospectively reviewed all cases with HC. We analyzed the etiologies, our treatment results and complications. RESULTS: Twenty-one children (48 %) presented either with HC or developed it over time. In 21 % of those cases, high venous pressure was presumably the sole cause. Until 2009, seven of them received ventriculoperitoneal (VP) shunting; six of those resulted in severe postoperative complications. The remaining children have been treated successfully by endovascular embolization. Five out of the 44 children (11 %) developed HC after intraventricular hemorrhage. In four cases, those children were treated with positive results by using transient external ventricular drainages. In one case a VP shunt with highest valve pressure was inserted. Another four children (9 %) presented with aqueductal stenosis-related HC caused by either dilated venous outflow or space-occupying coil masses after embolization. The latter case was successfully treated by ventriculocisternostomy, whereas endovascular treatment decreased the venous outflow in size and thus resolved the HC in the other cases. In the remaining cases (7 %), atrophy due to melting brain syndrome led to HC ex vacuo. CONCLUSIONS: HC in VGM is a common phenomenon with several etiologies requiring different treatments. In most cases, embolization of the VGM as sole treatment is completely sufficient in order to decrease high venous pressure. However, certain other causes of HC should be treated in an interdisciplinary setting by specialized neurosurgeons.

Kissing-Y stenting for endovascular treatment of complex wide necked bifurcation aneurysms using Acandis Acclino stents: results and literature review.

INTRODUCTION: Y-configured stent assisted coiling is a promising therapeutic option to ensure safe coil embolization and preserve the affected arteries in complex wide necked aneurysms. We present our experience with self-expanding Acandis Acclino stents for the treatment of complex aneurysms using the kissing-Y technique. METHODS: We retrospectively reviewed seven patients with seven complex aneurysms (three anterior communicating artery (AcomA), two middle cerebral artery, one basilar artery/superior cerebellar artery, and one vertebral artery/posterior inferior cerebellar artery) who were treated with the kissing-Y technique by stent assisted coiling from June 2013 to July 2014, with follow-up until January 2015. DSA follow-up was up to 17 months, with a mean follow-up period of 10 months. Six patients were treated electively and one in the acute phase of a subarachnoid hemorrhage. In all cases, closed cell Acandis Acclino stents were used. We evaluated procedural complications, clinical outcomes, and mid term angiographic follow-up. Additionally, a literature review is provided. RESULTS: In all patients, stents were successfully placed and implanted. One patient developed a periprocedural thromboembolic complication not directly related to the stents. No other periprocedural or postprocedural complications were encountered. Follow-up examinations showed stable and total occlusion of all coiled aneurysms. CONCLUSIONS: The results of our study show that the kissing-Y technique using closed cell Acandis Acclino stents followed by coil embolization is a feasible treatment option for selected complex bifurcation aneurysms.