Pathomorphometry of ruptured intracranial vertebral arterial dissection: adventitial rupture, dilated lesion, intimal tear, and medial defect

Flow alteration surgery using a radial artery graft for recurrent ruptured vertebral artery dissecting aneurysm after stent-assisted coil embolization: A case report

BACKGROUND

Ruptured vertebral artery dissecting aneurysm (VADA) is often treated surgically with coil embolization and sometimes recurs. We herein report a case of recurrent ruptured VADA after stent-assisted coil embolization (SAC) that was successfully treated with flow alteration surgery using a radial artery (RA) graft.

CASE DESCRIPTION

A 67-year-old woman presented with headache and coma. Enhanced CT revealed subarachnoid hemorrhage due to right VADA. Since the left VA was hypoplastic, the aneurysm was treated with SAC. However, follow-up angiography revealed recurrence of the aneurysm. Additional embolization was not considered due to the small size of the recurrent lesion and the presence of a stent; therefore, flow alteration surgery was performed using a RA graft. There were no neurological deficits after surgery or recurrence.

CONCLUSION

Flow alteration surgery using a RA graft is useful for recurrent VADA after SAC.

Spontaneous intracranial vertebral artery dissections presenting with subarachnoid hemorrhage

BACKGROUND

Vertebral artery dissection (VAD) is an infrequent source of subarachnoid hemorrhage (SAH), with a high mortality rate, primarily due to the risk of rebleeding both before and after medical intervention. This paper provides a comprehensive analysis of the anatomy, pathophysiology, clinical presentation, treatment strategies, and outcomes of intracranial vertebral artery dissections that result in subarachnoid hemorrhage.

METHODS

Comprehensive five-year literature review (2018-2022) and a retrospective analysis of patient records from our institution between 2016 and 2022. We included studies with a minimum of 5 patients.

RESULTS

The study incorporated ten series from the literature and 22 cases from CHUM. Key anatomical factors increasing the risk of VAD include the vertebral artery's origin from the aortic arch, asymmetry of the vertebral artery, and its tortuosity. Patients may display specific collagen and genetic abnormalities. The occurrence of VAD appears to be more prevalent in men. Those with a ruptured intracranial VAD typically show prodromal symptoms and present with severe SAH. Rebleeding within the first 24 h is frequent. While standard imaging methods are usually adequate for VAD diagnosis, they may not provide detailed information about the perforator anatomy. Treatment approaches include both deconstructive and reconstructive methods.

CONCLUSION

Ruptured VAD is a critical, life-threatening condition. Many patients have a poor neurological status at presentation, and rebleeding prior to treatment is a significant concern. Deconstructive techniques are most effective in preventing rebleeding, whereas the efficacy of reconstructive techniques needs more investigation.

Case report: Fatal ischemic stroke induced by unruptured traumatic intracranial vertebral artery dissection

Intracranial vertebral artery dissection (IVAD) is rare and potentially fatal due to the risk of secondary subarachnoid hemorrhage once ruptured. Unruptured traumatic IVAD is even rarer and can result in ischemic stroke, yet mostly benign when timely diagnosed. Herein, we present an uncommon case of a patient who underwent a fatal ischemic stroke induced by unruptured traumatic IVAD. The patient was symptomatic soon after being physically assaulted but left untreated until acute deterioration for multiple brain infarctions occurred, secondary to IVAD-induced cerebellar stroke. Fifteen days later, he died, regardless of an urgently performed thrombectomy. Multiple serial histologic examinations revealed an unruptured dissection of the intracranial vertebral artery with a slit-like tear of the intimal and medial layers, considered to be the culprit lesion. The 15-day prolonged onset of stroke was rare in traumatic IVADs. Furthermore, the slit-like tear of the intimal layer in our case may support the initial intimal laceration hypothesis for VAD pathogenesis. Since limited pathohistological information is available regarding ischemic IVAD, we believe this rare case will be beneficial in understanding the pathophysiology of ischemic IVAD.

Association between smoking and intracranial artery dissection in patients aged less than 50 years: A propensity score-matched analysis

INTRODUCTION

Smoking is a common risk factor for stroke in the young population. Intracranial artery dissection (ICAD) is a major cause of stroke in this population. However, the association between smoking and ICAD in young patients is not well characterized. We aimed to evaluate the association between smoking and ICAD in young individuals using propensity score-matched analysis.

METHODS

We conducted a retrospective study of consecutive patients aged <50 years with ICAD who were admitted to Beijing Tiantan Hospital between January 2016 and December 2020. Patients with other non-atherosclerotic/non-aneurysmal cerebrovascular diseases were selected as controls. Propensity score matching was based on age and sex. Smoking and other vascular risk factors were compared between the two groups.

RESULTS

The ICAD and control group included 120 and 197 patients, respectively. Propensity score matching resulted in 70 matched pairs. Smoking was the only significant factor association with ICAD in the matched cohort (p=0.031).

CONCLUSIONS

In this propensity score-matched analysis, smoking showed a positive association with ICAD in young patients with common cerebrovascular diseases that were neither atherosclerotic nor aneurysmal. Further studies are required to investigate the predictive role of smoking for ICAD in the young population.

Morphological characteristics associated with ruptured intracranial vertebral artery dissecting aneurysms

OBJECTIVE

Morphological risk factors for the rupture of intracranial vertebral artery dissecting aneurysms (IVADAs) have not been well characterized. In this study, we aim to identify morphological characteristics associated with IVADA rupture.

METHODS

We conducted a retrospective study of 249 consecutive patients with single IVADAs (31 ruptured and 218 unruptured) admitted to Beijing Tiantan Hospital between January 2016 and December 2020. Various morphological parameters were measured using three-dimensional digital subtraction angiography images. Univariate and multivariate logistic regression analyses were performed to identify morphological characteristics associated with IVADA rupture.

RESULTS

Univariate regression analysis revealed that the coexistence of significant proximal and distal stenosis and posterior inferior cerebellar artery (PICA) involvement were associated with IVADA rupture, while the origin from the dominant vertebral artery was inversely associated with the rupture. Multivariate regression analysis demonstrated that the coexistence of significant proximal and distal stenosis (OR 22.00, 95% CI 5.60 to 86.70, p<0.001) and PICA involvement (OR 4.55, 95% CI 1.36 to 15.20, p=0.014) were independently associated with IVADA rupture.

CONCLUSION

The coexistence of significant proximal and distal stenosis and PICA involvement were independently associated with IVADA rupture. These morphological characteristics may facilitate the assessment of rupture risk in patients with IVADAs.

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Computational fluid dynamics (CFD) analysis in a ruptured vertebral artery dissecting aneurysm implanted by Pipeline when recurrent after LVIS-assisted coiling treatment: Case report and review of the literatures

BACKGROUNDS

Hemodynamics plays an important role in the natural history of the process of rupture and recurrence of intracranial aneurysms. This study aimed to investigate the role of hemodynamics for recurrence in a vertebral artery dissecting aneurysm (VADA).

METHODS

A patient with a ruptured VADA firstly treated by low-profile visualized intraluminal support (LVIS)-assisted coiling, and was implanted with a Pipeline Embolization Device (PED) after aneurysm recurrence. Finite element analysis and computational fluid dynamics simulations were conducted in 6 serial imaging procedures, and the calculated hemodynamics was correlated with aneurysm recurrence.

RESULTS

Wall shear stress (WSS) was not effectively suppressed, resulting in aneurysm recurrence with initial entry tear to occur above the protuberance after 7 months of LVIS stent-assisted coiling. With the implantation of PED, WSS, inflow stream and velocity at the aneurysm neck significantly decreased. During the 3-month follow-up after PED deployment, there was significant shrinkage of the sac and the blood flow in the sac was reduced considerably. The 27-month follow-up after PED deployment indicated the aneurysm was stable.

CONCLUSIONS

The present case study suggests that insufficient suppression of high WSS and high inflow velocity at the neck of the parent artery, especially near the posterior inferior cerebellar artery, might be associated with aneurysm recurrence.

Angiographic characteristics of ruptured versus unruptured vertebral artery dissecting aneurysm

Objective

Vertebral artery dissecting aneurysm (VADA) is a rare and critical disease. VADA rupture can cause subarachnoid hemorrhage which is a major complication of VADA due to their high rebleeding rate and poor outcome. In the present study, ruptured and unruptured VADAs were compared by analyzing angiographic findings to determine useful predisposing factors for VADA rupture for appropriate treatment selection.

Methods

Subjects with VADA treated during a 10-year period were retrospectively identified. The 57 cases diagnosed with VADA were divided into ruptured (n=15) and unruptured (n=42) groups. In addition, each case was analyzed using angiographic 3-dimensional (3-D) reconstructed images. Factors such as length, dilated and stenotic diameter, shape, and vessel around the vertebral artery (VA) were measured and statistically compared.

Results

In the ruptured group, stenotic findings of the affected lesion were more common and severe than in the unruptured group. The average stenotic diameter was 2.27 mm (vs. 2.84 mm). And stenotic degree was 62% and 53% in the ruptured and unruptured groups, respectively. Posterior communicating artery (PcomA) flow was more common in the ruptured group (87% vs. 55%, p=0.028).

Conclusions

Based on angiographic findings, stenotic lesions, which may be influenced by PcomA flow, are more common in ruptured VADAs.

Low-profile visible intraluminal support stent-assisted embolization therapy for intracranial dissecting aneurysms: A retrospective analysis of six cases

Endovascular Embolization (EVE) of aneurysms is a very effective and efficient treatment modality. Nevertheless, a few complications have been reported after EVE of aneurysms. Our study therefore evaluated the safety and efficacy of Low-profile Visible Intraluminal Support (LVIS) stentassisted EVE for intracranial Dissecting Aneurysms (DAs). We conducted a retrospective study to identify patients with DAs who were treated with LVIS stent from July 2015 to September 2018. The DAs were categoried into ruptured and unruptured. The arteries harbouring the aneurysm were identified in all cases. LVIS device stent assisted coil EVE treatment modality was utilized to treat all the patients. Surgical safety, immediate surgery outcome, recurrence rate and imaging follow-up results of all patients were analysed. The Glasgow Outcome Scale (GOS) score of all patients where assessed during discharge. Cerebral angiography of all patients were reevaluated on scheduled visits from three months up to one year after their operations. A total of Six DA patients were identified during our analysis. Four of the cases were ruptured DAs while two cases were unruptured. The DAs originated from the Internal Carotid Artery (ICA) in two cases, while in the remaining four cases, the DAs originated from vertebral artery (VA). Stents and coils were successfully implanted in all six patients. The DAs were embolized satisfactorily and the parent arteries were patent immediately after the operations. We obsereved 5 points GOS score in four cases and 4 points in two cases. No aneurysmal recurrece, no stent collapse or displacement was obsereved in all cases during follow-ups. Our study suggests that, LVIS stent-assisted EVE is simple, safe and effective in the treatment of DAs.

Endovascular treatment of intracranial 'blister' and dissecting aneurysms

INTRODUCTION

Blister and dissecting aneurysms may have a different pathological background but they are commonly defined by instability of the vessel wall and bear a high risk of fatal rupture and rerupture. Lack of aneurysm sack makes treatment challenging.

PURPOSE

The purpose of this study was to assess the safety and feasibility of endovascular treatment of intracranial blister and dissecting aneurysms.

METHODS

We retrospectively analysed all patients with ruptured and unruptured blister and dissecting aneurysms treated endovascularly between 2004-2018. Procedural details, complications, morbidity/mortality, clinical favourable outcome (modified Rankin Scale ≤2) and aneurysm occlusion rates were assessed.

RESULTS

Thirty-four patients with endovascular treatment of 35 aneurysms (26 dissecting aneurysms and 9 blister aneurysms) were included. Five aneurysms were treated by parent vessel occlusion, and 30 aneurysms were treated by vessel reconstruction using stent monotherapy (n = 9), stent-assisted coiling (n = 7), flow diverting stents (n = 13) and coiling + Onyx embolization (n = 1). No aneurysm rebleeding and no procedure-related major complications or deaths occurred. There were five deaths in consequence of initial subarachnoid haemorrhage. Complete occlusion (79.2%) was detected in 19/24 aneurysms available for angiographic follow-up, and aneurysm recurrence in 2/24 (8.3%). The modified Rankin Scale ≤2 rate at mean follow-up of 15.1 months was 64.7%.

CONCLUSION

Treatment of blister and dissecting aneurysms developed from coil embolization to flow diversion with multiple stents to the usage of flow diverting stents. Results using modern flow diverting stents encourage us to effectively treat this aneurysm entity endovascularly by vessel reconstruction. Therefore, we recommend preference of vessel reconstructive techniques to parent vessel occlusion.

Treatment of intracranial vertebral artery dissecting aneurysms involving the posterior inferior cerebellar artery origin

Background

Vertebral artery dissecting aneurysm (VADA) involving the origin of the posterior inferior cerebellar artery (PICA) is a complex disease entity in which the dual goals of preventing future rebleeding and maintaining perfusion of the lateral medulla must be considered. We present an illustrative case and review the literature surrounding treatment strategies.

Case Description

We report a patient presenting with extensive subarachnoid hemorrhage due to rupture of an intracranial VADA involving the PICA origin. After consideration of the patient's cerebral vasculature and robustness of collaterals, a flow-diverting stent was placed with angiographic resolution of the lesion and maintenance of antegrade PICA flow. Ultimately, the patient experienced a contralateral intraparenchymal hemorrhage leading to death. Review of the literature identified 124 cases of VADA involving the PICA origin described over the past decade. The methods of surgical and endovascular treatment of these cases were reviewed, with particular focus on the rationale of treatment, outcomes, and complications.

Conclusion

Numerous treatment options for VADA involving PICA have been reported with different risk and benefit profiles. Flow-diverting stents appear to offer the most favorable balance of securing the aneurysm and avoiding medullary infarction, but the risks and optimal anti-thrombotic treatment strategy are incompletely understood. In select cases, in which the surgical risk is low or in which the anatomy is favorable (e.g., nondominant parent vessel or robust collateral circulation in the involved territories), parent artery trapping with or without microsurgical revascularization can be considered.

Clinical application of high-resolution MRI in combination with digital subtraction angiography in the diagnosis of vertebrobasilar artery dissecting aneurysm: An observational study (STROBE compliant)

Vertebrobasilar artery dissecting aneurysm (VBA-DA) is associated with serious complications and poor prognosis in patients. High-resolution magnetic resonance imaging (HR-MRI) is a noninvasive method for the diagnosis of VBA-DA.VBA-DAs were classified according to the feature of HR-MRI in combination with digital subtraction angiography (DSA), and the clinical outcomes of different types of VBA-DAs were analyzed. Thirty-nine patients with 42 VBA-DAs were included and underwent HR-MRI, including three-dimensional T1 weighted image, three-dimensional T2 weighted image (3D-T2WI), three-dimensional time of flight MRA (3D-TOF-MRA), and three-dimensional fast imaging employing steady state acquisition (3D-FIESTA), and hematoma and flaps were compared. The follow-up was 3 to 25 months. The VBA-DAs were classified based on the images of HR-MRI and DSA, and the prognosis was analyzed.VBA-DAs more frequently occurred on the vertebral artery, especially on the dominant vertebral artery. 3D-TOF-MRA showed high signal from hematoma, and 3D-FIESTA showed high signal from flaps. Based on HR-MRI images in combination with DSA, VBA-DAs were classified into 4 types: classical, stenosis, spiral, and hemorrhagic. The patients with the classical VBA-DAs had a higher improvement rate and a lower exacerbation rate. The patients with spiral and hemorrhagic VBA-DAs had poor clinical outcomes. The patients with stenosis VBA-DAs had poorer clinical outcomes than classical types and better clinical outcomes than spiral and hemorrhagic types.The detection of intramural hematoma and dissection flap using HR-MRI provides basic information for the diagnosis of VBA-DA. Individualized therapeutic strategies can be designed for the treatment of VBA-DAs with different features of DSA and HR-MRI.

Plasma Soluble Human Elastin Fragments as an Intra-Aneurysmal Localized Biomarker for Ruptured Intracranial Aneurysm

Background Fragmentation of the tunica media is a hallmark of intracranial aneurysm formation, often leading to aneurysmal progression and subsequent rupture. The objective of this study is to determine the plasma level of elastin fragments in the lumen of ruptured versus unruptured human intracranial aneurysms. Methods and Results One hundred consecutive patients with/without ruptured saccular intracranial aneurysms undergoing endovascular coiling or stent-assisted coiling were recruited. Blood samples were collected from the lumen of intracranial aneurysm using a microcatheter. The tip of the microcatheter was placed inside the aneurysm's sac in close proximity to the inner wall of the dome. Plasma levels of elastin fragments were measured using an ELISA -based method. Mean plasma level of soluble human elastin fragments was significantly greater in ruptured aneurysms when compared with nonruptured aneurysms (102.0±15.5 versus 39.3±9.6 ng/mL; P<0.001). Mean plasma level of soluble human elastin fragments did not have significant correlation with age, sex, size, or aneurysm location. Conclusions The present study revealed that a significantly higher concentration of soluble human elastin fragments in the lumen of ruptured intracranial aneurysms when compared with nonruptured ones.

Unexpected intraabdominal hemorrhage due to segmental arterial mediolysis following subarachnoid hemorrhage: A case of ruptured intracranial and intraabdominal aneurysms

Background:

Segmental arterial mediolysis (SAM) is an uncommon vascular disease, which manifests as catastrophic intraabdominal hemorrhage caused by rupture of visceral dissecting aneurysms in most cases. The etiology of SAM is still unclear, but SAM may be a vasospastic disorder and the responsible pressor agent is norepinephrine. Recently, abdominal SAM coexisting with intracranial dissecting aneurysms has been reported, but the relationship between intraabdominal and intracranial aneurysms in SAM remains unclear, as no cases of concomitant abdominal SAM and ruptured intracranial saccular aneurysm have been reported.

Case Description:

A 49-year-old woman underwent emergent clipping for a ruptured saccular aneurysm at the left C1 portion of the internal carotid artery. Intraoperatively, norepinephrine was continuously administered intravenously under general anesthesia. Four days after the subarachnoid hemorrhage (SAH), the patient suddenly developed shock due to massive hematoma in the abdominal cavity. Imaging showed multiple aneurysms involving the splenic artery, gastroduodenal artery, common hepatic artery, and superior mesenteric artery. Coil embolization of the splenic artery was performed immediately to prevent bleeding. Subsequent treatment for cerebral vasospasm following SAH was performed with prevention of hypertension, and the patient recovered with left temporal lobe infarction. The diagnosis was abdominal SAM based on the clinical, imaging, and laboratory findings.

Conclusion:

Norepinephrine release induced by SAH and/or iatrogenic administration of norepinephrine may have promoted abdominal SAM in this case. Abdominal SAM may occur subsequent to rupture of ordinary saccular aneurysm, and may provoke catastrophic abdominal hemorrhage in the spasm stage after SAH.

Treatment outcomes in cerebral artery dissection and literature review

Methods Patients with cerebral artery dissections were reviewed in a hospital setting from 2008 to 2015. Clinical presentations, lesion locations, treatment modalities, functional outcomes, and mortality were reviewed. Parent artery occlusion was the first choice for surgery or endovascular treatment of a hemorrhagic dissecting cerebral artery. Endovascular or surgical reconstructive treatment was indicated in patients whose parent artery could not be occluded. Favorable functional outcomes were determined using modified Rankin Scale (mRS) scores of 0-2. Results In total, 61 patients with cerebral artery dissections were admitted to the hospital. Seven (11.5%) had traumatic dissections. All traumatic dissections were located in the internal carotid arteries. Overall favorable outcome rate was about 57% (4/7). Spontaneous cerebral artery dissections were found in 54 patients. No difference in favorable outcomes was observed between parent vessel occlusion and selective occlusion with parent vessel preservation (or vessel reconstruction) (70% and 63%, respectively, p = 1.000). Patients who presented with spontaneous dissection without intracranial hemorrhage had more favorable outcomes than those with intracranial hemorrhage (79% and 52%, respectively, p = 0.045). The mortality rate of patients with spontaneous dissection was 7.4%. Conclusions Most of the traumatic dissections were located on the internal carotid arteries and spontaneous dissections were commonly located on vertebral arteries. Nonhemorrhagic spontaneous cerebral dissections had better functional outcomes after treatment. Endovascular and surgical management were effective treatments by parent vessel occlusion or reconstructions.

Stent-Assisted Coil Embolization of Vertebrobasilar Dissecting Aneurysms: Procedural Outcomes and Factors for Recanalization

Objective

Outcomes of stent-assisted coil embolization (SACE) have not been well established in the setting of vertebrobasilar dissecting aneurysms (VBDAs) due to the low percentage of cases that need treatment and the array of available therapeutic options. Herein, we presented clinical and radiographic results of SACE in patients with VBDAs.

Materials and Methods

A total of 47 patients (M:F, 30:17; mean age ± SD, 53.7 ± 12.6 years), with a VBDA who underwent SACE between 2008 and 2014 at two institutions were evaluated retrospectively. Medical records and radiologic data were analyzed to assess the outcome of SACE procedures. Cox proportional hazards regression analysis was conducted to determine the factors that were associated with aneurysmal recanalization after SACE.

Results

Stent-assisted coil embolization technically succeeded in all patients. Three cerebellar infarctions occurred on postembolization day 1, week 2, and month 2, but no other procedure-related complications developed. Immediately following SACE, 25 aneurysms (53.2%) showed no contrast filling into the aneurysmal sac. During a mean follow-up of 20.2 months, 37 lesions (78.7%) appeared completely occluded, whereas 10 lesions showed recanalization, 5 of which required additional embolization. Overall recanalization rate was 12.64% per lesion-year, and mean postoperative time to recanalization was 18 months (range, 3–36 months). In multivariable analysis, major branch involvement (hazard ratio [HR]: 7.28; p = 0.013) and the presence of residual sac filling (HR: 8.49, p = 0.044) were identified as statistically significant independent predictors of recanalization. No bleeding was encountered in follow-up monitoring.

Conclusion

Stent-assisted coil embolization appears feasible and safe for treatment of VBDAs. Long-term results were acceptable in a majority of patients studied, despite a relatively high rate of incomplete occlusion immediately after SACE. Major branch involvement and coiled aneurysms with residual sac filling may predispose to recanalization.

Reconstructive endovascular treatment of ruptured vertebral artery dissection involving the posterior inferior cerebellar artery

Two cases with ruptured vertebral artery (VA) dissection involving the origin of the posterior inferior cerebellar artery (PICA) are presented. Endovascular proximal occlusion of the dissected segment proximal to the PICA origin was performed, leaving the PICA patent in the acute stage. Stent placement from the PICA to the VA through the contralateral VA and coil embolization were added to the residual dissection in the chronic stage. Rebleedings were not observed. This is the first report of a staged, combined strategy for the treatment of a ruptured PICA involving VA dissection, which enabled preservation of the PICA without bypass surgery.

Evaluation of the Arterial Wall in Vertebrobasilar Artery Dissection Using High-Resolution Magnetic Resonance Vessel Wall Imaging

BACKGROUND

High-resolution magnetic resonance vessel wall imaging (HRMR-VWI) has been used to explore vascular diseases such as vasculitis and vulnerable plaque of intracranial arteries. Although vessel wall inflammation is suspected as one of the causes of cerebral arterial dissection, there have been few reports regarding the application of HRMR-VWI to arterial dissection. We have therefore evaluated the efficacy of HRMR-VWI in patients with vertebrobasilar artery dissection.

METHODS

HRMR-VWI was performed on 5 patients who had been diagnosed with nonhemorrhagic vertebrobasilar artery dissection.

RESULT

Four patients exhibited vessel wall enhancement on HRMR-VWI, the range of which corresponded with the dissection sites identified by cerebral angiogram, magnetic resonance imaging, or magnetic resonance angiography. The enhancements observed in all cases were extensive as compared with the findings of conventional angiography.

CONCLUSION

HRMR-VWI is thought to elucidate the condition of the affected vessel wall more in detail as compared with conventional methods.

Therapeutic Progress in Treating Vertebral Dissecting Aneurysms Involving the Posterior Inferior Cerebellar Artery

Among the variations of vertebral artery dissecting aneurysms (VDAs), VDAs involving the posterior inferior cerebellar artery (PICA), especially ruptured and high-risk unruptured aneurysms, are the most difficult to treat. Because the PICA is an important structure, serious symptoms may occur after its occlusion. Retained PICAs are prone to re-bleeding because VDAs are difficult to completely occlude. There is therefore confusion regarding the appropriate treatment for VDAs involving the PICA. Here, we used the PubMed database to review recent research concerning VDAs that involve the PICA, and we found that treatments for VDAs involving the PICA include (i) endovascular treatment involving the reconstruction of blood vessels and blood flow, (ii) occluding the aneurysm using an internal coil trapping or an assisted bypass, (iii) inducing reversed blood flow by occluding the proximal VDA or forming an assisted bypass, or (iv) the reconstruction of blood flow via a craniotomy. Although the above methods effectively treat VDAs involving the PICA, each method is associated with both a high degree of risk and specific advantages and disadvantages. The core problem when treating VDAs involving the PICA is to retain the PICA while occluding the aneurysm. Therefore, the method is generally selected on a case-by-case basis according to the characteristics of the aneurysm. In this study, we summarize the various current methods that are used to treat VDAs involving the PICA and provide schematic diagrams as our conclusion. Because there is no special field of research concerning VDAs involving the PICA, these cases are hidden within many multiple-cases studies. Therefore, this study does not review all relevant documents and may have some limitations. Thus, we have focused on the mainstream treatments for VDAs that involve the PICA.

High-Dose Menaquinone-7 Supplementation Reduces Cardiovascular Calcification in a Murine Model of Extraosseous Calcification

Cardiovascular calcification is prevalent in the aging population and in patients with chronic kidney disease (CKD) and diabetes mellitus, giving rise to substantial morbidity and mortality. Vitamin K-dependent matrix Gla-protein (MGP) is an important inhibitor of calcification. The aim of this study was to evaluate the impact of high-dose menaquinone-7 (MK-7) supplementation (100 µg/g diet) on the development of extraosseous calcification in a murine model. Calcification was induced by 5/6 nephrectomy combined with high phosphate diet in rats. Sham operated animals served as controls. Animals received high or low MK-7 diets for 12 weeks. We assessed vital parameters, serum chemistry, creatinine clearance, and cardiac function. CKD provoked increased aortic (1.3 fold; p < 0.05) and myocardial (2.4 fold; p < 0.05) calcification in line with increased alkaline phosphatase levels (2.2 fold; p < 0.01). MK-7 supplementation inhibited cardiovascular calcification and decreased aortic alkaline phosphatase tissue concentrations. Furthermore, MK-7 supplementation increased aortic MGP messenger ribonucleic acid (mRNA) expression (10-fold; p < 0.05). CKD-induced arterial hypertension with secondary myocardial hypertrophy and increased elastic fiber breaking points in the arterial tunica media did not change with MK-7 supplementation. Our results show that high-dose MK-7 supplementation inhibits the development of cardiovascular calcification. The protective effect of MK-7 may be related to the inhibition of secondary mineralization of damaged vascular structures.

Recanalization of a ruptured vertebral artery dissecting aneurysm after occlusion of the dilated segment only

Background:

Internal trapping in which the dissecting aneurysm is occluded represents reliable treatment to prevent rebleeding of ruptured vertebral artery (VA) dissecting aneurysms. Various methods of internal trapping are available, but which is most appropriate for preventing both recanalization of the VA and procedural complications is unclear.

Case Description:

A 61-year-old male presented with subarachnoid hemorrhage caused by rupture of a left VA dissecting aneurysm. Only the dilated segment of the aneurysm was occluded by coil embolization. Sixteen days after embolization, angiography showed recanalization of the treated left VA with blood supplying the dilated segment of the aneurysm, which showed morphological change between just proximal to the coil mesh and just distal to a coil, and antegrade blood flow through this part. Pathological examination showed that the rupture site that had appeared to be the most dilated area on angiography was located just above the orifice of the entrance. However, we think that this case of ruptured aneurysm had an entrance into a pseudolumen that existed proximal to the dilated segment, with antegrade recanalization occurring through the pseudolumen with morphological change because of insufficient coil obliteration of the entrance in the first therapy.

Conclusions:

This case suggests that occlusion of both the proximal and dilated segments of a VA dissecting aneurysm will prevent recanalization, by ensuring that any entrance to a pseudolumen of the aneurysm is completely closed. Careful follow-up after internal trapping is important, since antegrade recanalization via a pseudolumen may occur in the acute stage.

Retreatment and outcomes of recurrent intracranial vertebral artery dissecting aneurysms after stent assisted coiling: a single center experience

Background and purpose

The retreatment of recurrent intracranial vertebral artery dissecting aneurysms (VADAs) after stent assisted coiling (SAC) has not yet been studied. The purpose of this study was to evaluate the strategies and outcomes for retreatment of recurrent VADAs after SAC.

Methods

Between September 2009 and November 2013, six consecutive patients presenting with recurrent intracranial VADAs after SAC were enrolled in this study. They were all male with age ranging from 29 to 54 years (mean age, 46.2 years). The procedures of treatments and angiographic and clinical follow-up were reviewed retrospectively. Retreatment modalities were selected individually according to the characteristics of recurrence. The outcomes of retreatment were evaluated by angiographic and clinical follow-up.

Results

Six patients with recurrent intracranial VADAs after SAC were retreated, with second SAC in three patients, coil embolization, double overlapping stents placement and endovascular occlusion with aneurysm trapping in one patient, respectively. Immediate angiographic outcomes of retreatment were: complete occlusion in three patients, nearly complete occlusion in two patients, and contrast medium retention in dissecting aneurysm in one patient. All cases were technically successful. No complications related to endovascular procedures occurred. Angiographic follow-up was available in all five patients treated with second SAC or double overlapping stents, which was complete occlusion in four patients, obliteration of parent artery in one patient, showing no recurrence at 4–11 months (mean: 8.6 months). Clinical follow-up was performed in all six patients at 11–51 months after initial endovascular treatment and at 9–43 months after retreatment. The mRS of last clinical follow-up was excellent in five patients and mild disability in only one patient.

Conclusions

Endovascular retreatment is feasible and effective for recurrent intracranial VADAs after SAC. Individualized strategies of retreatment should be enacted according to the characteristics and reasons for the recurrence.

Detection of vessel wall lesions in spontaneous symptomatic vertebrobasilar artery dissection using T1-weighted 3-dimensional imaging

BACKGROUND

Spontaneous intracranial vertebrobasilar artery dissection (iVBD) is a cause of ischemic stroke and subarachnoid hemorrhage in young adults that can be detected noninvasively by using multisequence magnetic resonance imaging (MRI). However, MRI findings are sometimes difficult to interpret, and its accuracy tends to be suboptimal, especially during the acute period. Therefore, we investigated whether 3-dimensional (3D) vessel wall imaging (VWI) technique could readily detect iVBD lesions in acute phase patients.

METHODS

Sixteen consecutive patients with acute ischemic stroke caused by iVBD were prospectively examined with a 1.5-T magnetic resonance scanner. T1-weighted (T1W) 3D-VWI was obtained using a flow-sensitized 3D fast spin-echo technique. In addition, multisequence MRI comprising magnetic resonance angiography (MRA), basiparallel anatomical scanning (BPAS), and axial T1W imaging (T1WI) were also examined. Presence of luminal stenosis, aneurysmal dilatation, intramural high signal, and intimal flap/double lumen of the vertebral and basilar arteries were visually assessed using each technique.

RESULTS

On 3D-VWI, luminal stenosis, aneurysmal dilatation, intramural high signal, and intimal flap were observed in 16 (100%), 11 (68.8%), 16 (100%), and 1 (6.3%) patients, respectively. In contrast, on conventional techniques, these findings were observed in 15 (93.8%, MRA with BPAS), 12 (75.0%, MRA with BPAS), 12 (75.0%, T1WI), and 12 (75.0%, MRA) patients, respectively.

CONCLUSIONS

The T1W 3D-VWI can directly visualize vessel wall iVBD lesions during the acute period of stroke compared with multisequence MRI.