Unruptured Vertebral Artery Dissecting Aneurysms Research Articles

A multidimensional pre-operative planning method of unruptured vertebral artery dissecting aneurysms using three-dimensional AWE mapping and hemodynamic simulation

ObjectiveHigh-resolution magnetic resonance imaging (HR-MRI) can provide valuable insights into the evaluation of vascular pathological conditions, and 3D digital subtraction angiography (3D-DSA) offers clear visualization of the vascular morphology and hemodynamics. This study aimed to investigate the potential of a multimodal method to treat unruptured vertebral artery dissection aneurysms (u-VADAs) by fusing image data from HR-MRI and 3D-DSA. MethodsThis observational study enrolled 5 patients diagnosed with u-VADAs, who were scheduled for interventional treatment. The image data of HR-MRI and 3D-DSA were merged by geometry software, resulting in a multimodal model. Quantified values of aneurysm wall enhancement (AWE), wall shear stress (WSS), neck velocity, inflow volume, intra-stent flow velocity (ISvelocity), and intra-aneurysmal velocity (IAvelocity) were calculated from the multimodal method. ResultsWe found the actual lengths of u-VADAs in the multimodal model were longer than the 3D-DSA model. We formulated surgical plannings based on the WSS, IA velocity, and neck velocity. The post-operative value of IAvelocity, neck velocity, and follow-up quantified values of AWE were decreased compared with the pre-operative condition. After that, u-VADAs were complete occlusion in four patients and near-complete occlusion in one patient during the 6th-month follow-up after surgery. ConclusionThe multidimensional method combining HR-MRI with 3D-DSA may provide more valuable information for treating VADAs, with the potential to develop effective surgical planning.

Multiple telescopic stenting versus single flow diverter for the treatment of vertebral artery dissecting aneurysm.

Reconstruction methods, including stent-assisted coiling, multiple telescopic stents, and flow diverters, are preferred modalities for the treatment of unruptured vertebral artery dissecting aneurysms (VADAs). We aimed to compare the clinical outcomes between two reconstructive flow diversion techniques: single flow diverter (FD) device and multiple telescopic stenting (TS). We retrospectively reviewed the clinical data of 39 patients with unruptured VADAs. Of these, 17 patients were treated with multiple TS and 22 with a single FD device. Aneurysm characteristics and clinical outcomes were compared between the two groups. All aneurysms included in this study successfully achieved flow diversion, regardless of the treatment modality and duration. However, the mean procedure duration to complete the diversion was shorter in the FD group. Subgroup analysis in TS group showed that there were no significant clinical differences between the low-profile visualized intraluminal support and Enterprise stents, except for the mean procedure duration. Both the single FD and multiple TS methods showed excellent angiographic and clinical outcomes in the treatment of unruptured VADAs. However, single FD required a shorter procedure duration and was associated with faster achievement of complete flow diversion.

Clinical and Angiographic Outcomes of Endovascular Treatment for Acute Intracranial Vertebral Artery Dissecting Aneurysms Using Double-Overlapping Stents : Low-Profile Visualized Intraluminal Support within Enterprise Stents.

The use of reconstructive treatment with a double-overlapping stents has proven to be effective and safe in the current treatment of intracranial vertebral artery dissecting aneurysms (VADAs). We employed a combination of overlapping stents, using low-profile visualized intraluminal support (LVIS) within the Enterprise stent. This combination was chosen to minimize the outward bulging of the inner LVIS by overlapping it with the Enterprise stent while maintaining flow diversion and stability. This study aimed to evaluate the clinical and angiographic outcomes following the use of double-overlapping stents with LVIS within the Enterprise stent for the treatment of VADAs. From March 2016 to January 2022, total 28 patients with unruptured VADAs were treated with the double-overlapping stent technique using LVIS within an Enterprise stent in our institute. The Enterprise stent was deployed first, followed by the LVIS stent. Patient clinical and angiographic characteristics, procedural complications, and follow-up outcomes were retrospectively reviewed. All 28 patients (18 males and 10 females) were successfully treated with double-overlapping stent deployment. There were no procedural complications or new neurological deficits in any patient. Of the 28 patients, four VADAs had posterior inferior cerebellar artery involvement. Procedure-related parent artery occlusion did not occur during the angiographic follow-up conducted 6 to 12 months after the procedure. Out of 28 patients, 24 showed complete healing, three had focal residual stenosis or dilatation with residual sac and only one had a residual dissecting flap with aneurysm. All patients, including the four patients, did not require any additional procedures. The postoperative modified Rankin Scale (mRS) scores were 0-1 for all patients. A double-overlapping stent, with a flow-diversion effect, is a safe and effective treatment for patients with VADAs. In particular, when using the LVIS stent within an Enterprise stent, it minimizes the bulging of the inner LVIS stent while maintaining flow diversion and stability. Therefore, both can be effectively utilized as overlapping stents.

Low Wall Shear Stress and High Intra-aneurysmal Pressure are Associated with Ruptured Status of Vertebral Artery Dissecting Aneurysms.

The morphological and hemodynamic features of patients with vertebral artery dissecting aneurysms (VADAs) are yet unknown. This study sought to elucidate morphological and hemodynamic features of patients with ruptured and unruptured VADAs based on computed flow simulation. Fifty-two patients (31 unruptured and 21 ruptured VADAs) were admitted to two hospitals between March 2016 and October 2021. All VADAs were located in the intradural segment, and their clinical, morphological, and hemodynamic parameters were retrospectively analyzed. The hemodynamic parameters were determined through computational fluid dynamics simulations. Univariate statistical and multivariable logistic regression analyses were employed to select significantly different parameters and identify key factors. Receiver operating characteristic (ROC) analysis was used to assess the discrimination for each key factor. Four hemodynamic parameters were observed to significantly differ between ruptured and unruptured VADAs, including wall shear stress (WSS), low shear area, intra-aneurysmal pressure (IAP), and relative residence time. However, no significant differences were observed in morphological parameters between ruptured and unruptured VADAs. Multivariable logistic regression analysis revealed that low WSS and high IAP were significantly observed in the ruptured VADAs and demonstrated adequate discrimination. This research indicates significant hemodynamic differences, but no morphological differences were observed between ruptured and unruptured VADAs. The ruptured group had significantly lower WSS and higher IAP than the unruptured group. To further confirm the roles of low WSS and high IAP in the rupture of VADAs, large prospective studies and long-term follow-up of unruptured VADAs are required.

Endovascular treatment of vertebral artery dissecting aneurysms : a 20-year institutional experience

BackgroundThe ideal treatment for unruptured vertebral artery dissecting aneurysms (VADAs) and ruptured dominant VADAs remains controversial. We report our experience in the management and endovascular treatment of patients with VADAs.MethodsPatients...

Risk factors for medullary infarction after endovascular trapping of vertebral artery dissecting aneurysms

Internal trapping (IT) is a treatment option for intracranial vertebral artery dissecting aneurysms (VADAs). Medullary infarction (MI) is a complication linked to this treatment. This study aims to clarify the outcomes of IT for VADAs and the risk factors for MIs. We retrospectively reviewed the databases from 2010 to 2017 to identify patients with VADAs treated by IT at seven collaborating institutions. Radiological findings, clinical courses, and outcomes were analyzed. Perforating arteries were classified into terminal or longitudinal types using preoperative angiography. IT was completed in 90 patients (74 ruptured and 16 unruptured VADA). Postoperative rebleeding did not occur in any ruptured VADA patients. Postoperative MRI detected MIs in 26 patients (28.9%). The incidence of MIs in the ruptured VADA (32%) was higher compared with that in the unruptured VADA (13%), though it was not significant. In the MI group, the occlusion or blind alley of the terminal-type and longitudinal-type perforator was confirmed in 23 patients (88%) and 11 patients (42%), respectively. The occlusion or blind alley of the terminal-type perforator was an independent risk factor for MIs in the logistic regression analysis (OR 5.81; 95% CI 1.34-25.11; p = 0.018). In ruptured VADA, postoperative MI (OR 12.2; 95% CI 3.19-64.55; p = 0.0001) and high-grade SAH (OR 8.02; 95% CI 2.32-37.70; p = 0.0006) were independent risk factors of an unfavorable clinical outcome. In conclusion,MIs were an independent risk factor for unfavorable outcomes after IT, especially for a ruptured VADA. The occlusion or blind alley of the terminal-type perforator caused by the IT was associated with postoperative MIs.

Unruptured Vertebral Artery Dissecting Aneurysms: Approach Strategy by Retrospective Analysis

Objectives: The natural course of un-ruptured vertebral artery dissecting aneurysms (VADAs) is not completely clear. We aim to retrospectively develop a strategy for treating un-ruptured VADAs based on long-term follow-up. Methods: We retrospectively studied 35 patients with un-ruptured VADAs. The initial symptom of 20 patients was headache, followed by ischemic symptoms and mass effect in 11 and 4 patients respectively. All of the patients underwent Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA) at the time of admission and 2 weeks and 1, 4, 6, 12, and 24 months after initial presentation. Asymptomatic patients with enlarging dissection site defined on MRI and MRA, received further treatment and work up. Results: Two patients received emergency intervention due to symptom exacerbation and unstable status. The other 33 patients underwent conservative management. Lesion enlargement was observed in 2 cases during imaging follow up. In follow up period, additional interventions including dissection trap by surgery and coil embolization were conducted in 1 and 3 patients respectively. Other 31 patients remain symptom free and were managed conservatively. Dissection site remained unchanged in majority of patients (68.57%), improved in 28.57% and disappeared in 2.85% of the patients. Ten patients with recurrent ischemic attacks underwent anti-platelet therapy, without any bleeding complaint or permanent neurological deficits. Conclusion: The nature of an un-ruptured VADA is not highly aggressive. However, enlarged dissection site without new manifestations, occlusion is recommended. Also, anti-platelet therapy is suggested in patients with recurrent ischemic attacks.

Predictive factors of medullary infarction after endovascular internal trapping using coils for vertebral artery dissecting aneurysms.

OBJECTIVE The first choice of treatment in cases of vertebral artery dissecting aneurysms (VADAs) is endovascular internal trapping (EIT) of the dissecting segment using coils. However, this procedure carries the risk of medullary infarction, and the risk factors for this complication are not well understood. This study investigated the risk factors causing medullary infarction. METHODS One hundred patients who underwent EIT for VADAs were included in this study. Ninety-three patients presented with subarachnoid hemorrhage. In cases involving the posterior inferior cerebellar artery (PICA), partial internal trapping targeting the ruptured site was performed to preserve the PICA. The VADAs were classified into the distal VA stump group, proximal VA stump group, and entire VA stump group, according to the location of VA segments without adequate flow-out vessels (such as the PICA [VA stump]) at risk of delayed thrombosis. The occurrence of medullary infarction was examined in each group using diffusion-weighted MRI and/or clinical symptoms. Various measurements were performed on digital subtraction angiography, and the risk factors for medullary infarction were analyzed. RESULTS Medullary infarction occurred in 30 patients, affecting the posterolateral medulla in 27 patients and the anteromedial medulla in 3 patients. Medullary infarction occurred in 3 of 47 patients (6%) in the distal VA stump group, 10 of 19 patients (53%) in the proximal VA stump group, and 17 of 34 patients (50%) in the entire VA stump group. The length of trapping was significantly longer in the infarction group than in the noninfarction group but did not differ among the 3 groups. Total length (length of trapping plus VA stump) was a risk factor for medullary infarction in the proximal VA stumps. CONCLUSIONS The primary risk factor for medullary infarction after EIT is not the length of trapping; rather, it is the anatomical location of the VADAs. The risk of medullary infarction is low in cases with distal VA stumps, but the symptoms are severe. Preservation of the origin of the anterior spinal artery can reduce the risk of medullary infarction. The risk of medullary infarction is high in cases with proximal VA stumps, but the symptoms are mild. A shorter length of trapping, although less likely to lead to complications, cannot prevent medullary infarction because the total length depends on the anatomical location of the PICA and not on the surgical technique. Reconstructive therapy should be indicated for patients with ruptured VADAs at high risk of severe ischemic complications (e.g., patients with hypoplasia of the contralateral VA or cases involving the PICA or anterior spinal artery, which are inappropriate for partial internal trapping) or for patients with unruptured VADAs.

Endovascular reconstruction of unruptured intradural vertebral artery dissecting aneurysms with the Pipeline embolization device

BackgroundDissecting aneurysms of the vertebral artery (VA) are difficult to treat using current surgical and endovascular techniques.ObjectiveTo analyze retrospectively the efficacy and safety of flow diverters in the treatment of...

Endovascular Treatment of Intracranial Vertebral Artery Dissecting Aneurysms: Follow up Angiographic and Clinical Results of Endovascular Treatment in Serial Cases.

PurposeTo report angiographic and clinical results of endovascular treatment in 45 intracranial vertebral artery dissecting aneurysms (VADAs).Materials and MethodsFrom July 2002 to September 2013, a total of 42 patients with 45 VADAs received endovascular treatment. Endovascular treatment consisted of internal trapping with detachable coils, stent-assisted coiling, and stenting only. Immediate and follow-up angiographic findings and clinical outcome were retrospectively reviewed.ResultsThere were 17 ruptured VADAs and 28 unruptured VADAs. Overall, 26 VADAs were treated with internal trapping, 14 with stent-assisted coil embolization, and 5 with stenting only. Immediate angiographic results revealed complete occlusion in 31 cases and incomplete occlusion in 14 cases. Follow-up imaging studies were available in 31 cases. On follow-up imaging, antegrade recanalization occurred in 2 of 16 cases treated with internal trapping. Aneurysmal recurrence occurred in one case treated with stent-assisted coiling. Procedural complications occurred in 8 patients. In cases of unruptured VADA, favorable outcome (mRS 0 and 1) was achieved in 26 cases and poor outcome (mRS 2-5) in 2 cases. There was no mortality in patients with unruptured VADAs.ConclusionEndovascular treatment of intracranial VADA appears to be safe and effective. Follow-up angiographic study is needed because parent artery recanalization or aneurysmal recurrence can occur.

Bilateral Vertebral Artery Dissecting Aneurysms Presenting with Subarachnoid Hemorrhage Treated by Staged Coil Trapping and Covered Stents Graft

The treatment of bilateral vertebral artery dissecting aneurysms (VADAs) presenting with subarachnoid hemorrhage (SAH) is still challenging. The authors report a rare case of bilateral VADA treated with coil trapping of ruptured VADA and covered stents implantation after multiple unsuccessful stent assisted coiling of the contralateral unruptured VADA. A 44-year-old woman was admitted to our hospital because of severe headache and sudden stuporous consciousness. Brain CT showed thick SAH and intraventricular hemorrhage. Cerebral angiography demonstrated bilateral VADA. Based on the SAH pattern and aneurysm configurations, the right VADA was considered ruptured. This was trapped with endovascular coils without difficulty. One month later, the contralateral unruptured VADA was protected using a stent-within-a-stent technique, but marked enlargement of the left VADA was detected by 8-months follow-up angiography. Subsequently two times coil packing for pseudosacs resulted in near complete occlusion of left VADA. However, it continued to grow. Covered stents graft below the posterior inferior cerebellar artery (PICA) origin and a coronary stent implantation across the origin of the PICA resulted in near complete obliteration of the VADA. Covered stent graft can be used as a last therapeutic option for the management of VADA, which requires absolute preservation of VA flow.

Strategy for Treating Unruptured Vertebral Artery Dissecting Aneurysms

The natural course of unruptured vertebral artery dissecting aneurysms (VADAs) remains unclear. The purpose of this retrospective study was to develop a strategy for treating unruptured VADAs based on long-term follow-up. Our study population consisted of 100 patients with unruptured VADAs; in 66, the initial symptom was headache only, 30 presented with ischemic symptoms and 4 with mass effect. All underwent magnetic resonance imaging and magnetic resonance angiography at the time of admission and 2 weeks and 1, 3, 6, 12, and 24 months after the onset. If the dissection site was demonstrated to be enlarged on magnetic resonance imaging and magnetic resonance angiography without the manifestation of new symptoms, the patients received additional treatment to prevent bleeding. Of the 100 patients, 4 underwent early intervention because of symptom exacerbation. The other 96 were initially treated conservatively; during follow-up, 5 manifested lesion enlargement on magnetic resonance angiography. Nine patients received additional treatment; 1 underwent direct surgery with trapping of the dissection site, and 8 underwent coil embolization. The other 91 patients continued to be treated conservatively; the dissection site remained unchanged in 70, improved or healed in 18, and disappeared in 3 patients. We treated 38 patients with recurrent ischemic attacks with antiplatelet therapy. No patients experienced bleeding or permanent neurological deficits during follow-up. The nature of an unruptured VADA is not highly aggressive. However, if the dissection site enlarges without the manifestation of new symptoms, it should be occluded. In patients with recurrent ischemic attacks antiplatelet therapy should be considered.

Endovascular Surgery using Stents for Vertebral Artery Dissecting Aneurysms and a Review of the Literature

The treatment of dissecting aneurysms of the vertebral artery (VA) involving the posterior inferior cerebellar artery (PICA) or presenting with hypoplasia of the contralateral VA is controversial. We describe our experience with 4 ruptured and 2 unruptured VA dissecting aneurysms and discuss the efficacy of endovascular surgery using stents. All patients were male; their mean age was 50.7 years. According to World Federation of Neurological Surgeons (WFNS) grading, 3 of the ruptured aneurysms were grade V, the other was grade I. All patients were successfully treated using stents; in 5 we also coil-embolized the aneurysmal lumen. One aneurysm was treated by the placement of 2 stents covering the dissection site; there was a danger of aneurysmal rupture during coil embolization. No technical complications were encountered although one patient suffered minor rebleeding 5 days post-treatment. Delayed vasospasm occurred in 4 cases. According to the Glasgow Outcome Scale (GOS), at 3 months after treatment 2 patients had made a good recovery, one was moderately disabled, one suffered severe disability, and 2 had died. One death each was due to acute myocardial and brain stem infarction. Endovascular surgery using stents may be a useful treatment in patients in poor condition who manifest dissecting VA aneurysms involving the PICA or hypoplasia of the contralateral VA, especially in the acute period after rupture.