Yibin Fang

Reconstructive Treatment of Ruptured Intracranial Spontaneous Vertebral Artery Dissection Aneurysms: Long-Term Results and Predictors of Unfavorable Outcomes

Introduction Few studies focused on predictors of unfavorable outcomes (modified Rankin Scale, 2–6) after reconstructive treatment of the ruptured intracranial spontaneous vertebral artery dissection aneurysms (ris-VADAs), which was evaluated based on 57 reconstructed lesions in this study. Methods Results of 57 consecutive patients (M:F = 29∶28; median age, 48 years; range, 27 to 69 years) harboring 57 ris-VADAs, which were treated with coils combined with single stent(n = 32), double overlapping stents (n = 16), and triple overlapping stents (n = 9) between October 2000 to March 2011, were retrospectively reviewed and analyzed. Results The available (n = 54) mean durations of angiographic and clinical follow-ups were 27 months (range, 12 to 78) and 62 months (range, 12 to 132), respectively. The involvement of PICA (p = 0.004), size of lesions (p = 0.000), quantity of stent (p = 0.001), and coil type (p = 0.002) affected the immediate obliteration grade, which was only risk factor for angiographic recurrences (p = 0.031). Although the post-treatment outcomes did not differ between single stent and multiple stents (p = 0.434), 5 angiographic recurrences, 1 rebleeding and 1 suspected rebleeding, all occurred in partial obliteration after single-stent-assisted coiling. Progressive thrombosis and in-stent obliteration were not detected on follow-up angiograms. Older age (odds ratio [OR] = 1.090; 95% confidence interval [CI], 1.004–1.184; p = 0.040) and unfavorable Hunt-Hess scale (OR = 4.289; 95%CI, 1.232–14.933; p = 0.022) were independent predictors of unfavorable outcomes in the reconstructed ris-VADAs. Conclusions Immediate obliteration grade was only risk factor for angiographic recurrence after reconstructive treatment. Unfavorable Hunt-Hess grade and older age were independent predictors of unfavorable outcomes in ris-VADAs.

Overlapping stents for blood blister-like aneurysms of the internal carotid artery.

OBJECTIVE Blood blister-like aneurysms (BBAs) are unique due to their high risk of recurrent bleeding associated with their fragile neck. The best treatment for BBAs is still controversial. This paper sought to evaluate the safety and efficacy of stent-assisted coiling and subsequent overlapping stents (SAC+OS) in the treatment of BBAs. METHODS Fifteen consecutive patients with ruptured BBAs managed with SAC+OS were enrolled in this study. The clinical characteristics, procedural data, angiographic outcome, and follow-up results were reviewed. RESULTS SAC+OS were successfully performed in all 15 cases. The instant angiographic result was total occlusion in 6 cases, residual neck in 7 cases, and residual aneurysm in 2 cases. Angiographic follow-ups revealed total occlusion in all 6 cases treated by triple or quadruple stents, and 6 of 9 cases treated by double stents. Major recanalization was detected in 3 cases treated by double stents. The modified Rankin Scale score at 4-52 months follow-up (23.8 months on average) was 0 in 6 cases, 1 in 8 cases, and 3 in one case. CONCLUSION Stent-assisted coiling and subsequent overlapping stents are feasible and safe for BBAs. It can be helpful to further decrease the risk of recanalization with more stents. Early angiographic follow-up within 2 weeks is recommended.

A Novel Flow-Diverting Device (Tubridge) for the Treatment of 28 Large or Giant Intracranial Aneurysms: A Single-Center Experience

BACKGROUND AND PURPOSE: The Tubridge flow diverter is a novel device developed in China and aimed at reconstructing the parent artery and occluding the aneurysm. We conducted this study to evaluate its feasibility, safety, and efficacy for the treatment of large or giant internal carotid artery aneurysms, which are still challenging with conventional therapy. MATERIALS AND METHODS: The clinical and angiographic data of 28 patients with 28 large or giant internal carotid artery aneurysms treated with Tubridge flow diverters were prospectively collected and analyzed. RESULTS: Thirty-three Tubridge flow diverters were successfully implanted except for 1 poor midstent opening; the result was a technical success rate of 97.0% (32/33). Follow-up angiographies were available for 25 aneurysms; the mean follow-up was 9.9 months (5–24 months). Of the 25 aneurysms, 18 (72.0%) were completely occluded, 6 (24.0%) were improved, and 1 (4.0%) was unchanged. All of the visible covered branches and parent arteries were patent, with no stenosis or obliteration. During a follow-up of 6–30 months (mean, 19 months), symptoms were resolved in 13 patients, improved in 6 patients, and unchanged in 4 patients. Five patients experienced transient clinical deterioration due to a postoperative increased mass effect. Procedure-related morbidity and mortality were both zero. CONCLUSIONS: Our preliminary experience shows that the Tubridge flow diverter is a safe and effective tool for treating large and giant internal carotid artery aneurysms. However, multicenter randomized trials and studies involving a long-term follow-up are necessary.

The safety and efficacy of low profile visualized intraluminal support (LVIS) stents in assisting coil embolization of intracranial saccular aneurysms: a single center experience

Background The low profile visualized intraluminal support (LVIS) device is a new generation of self-expanding braided stents recently introduced into China for stent assisted coiling of intracranial aneurysms. This study assessed the clinical safety and efficacy of the LVIS stent for embolization of intracranial saccular aneurysms. Methods Patients with intracranial saccular aneurysms treated using the LVIS device in our center between April 2014 and December 2014 were reviewed. The primary outcomes were procedural safety, target aneurysm recurrence, and mid-term follow-up of clinical and angiographic outcomes. Results 97 patients with intracranial saccular aneurysms were treated using the LVIS stent, with 100% technical success rate. No mortality was observed. One patient had transient deficit (1/97, 1.0%). Immediate angiographic outcome evaluation showed complete occlusion in 28 (28.8%) and neck remnant in 39 (40.2%) of the 97 patients, respectively. Of the 76 (78.35%) patients who underwent angiographic follow-up at a mean of 8.1 months, complete occlusion was achieved in 64 (84.2%) patients. In the remaining patients, neck remnant in nine (11.8%) and residual sac in three (4%) patients were observed. None of the patients had any target aneurysm recurrence, and the mortality rate was 0%. Conclusions The LVIS stent is safe and effective in the treatment of intracranial saccular aneurysms.

Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction

Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC <35%). Normalized mean wall shear stress (WSS), relative residence time (RRT), inflow velocity, and inflow volume in Group A were significantly different (P<0.05) from virtual FD deployment, but pressure was not (P>0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment.

A pivotal role of the vascular endothelial growth factor signaling pathway in the formation of venous hypertension-induced dural arteriovenous fistulas

Dural arteriovenous fistulas (DAVFs) are associated with venous hypertension. Numerous studies have revealed high expression levels of vascular endothelial growth factor (VEGF) in human DAVF specimens, as well as in animal models of experimental venous hypertension. The objective of the present study was to clarify whether the VEGF signaling pathway is important in the development of DAVFs. Rats (n=216) were randomly divided into six groups. In the rats from five groups (groups A and C-E, n=45 in each group; group B, n=12), experimental venous hypertension was induced by right common carotid artery (CCA)-external jugular vein (EJV) anastomosis, superior sinus occlusion and left transver sinus occlusion, while the remaining group (group F, n=24) underwent sham surgery. The rats in group A received a VEGF recombinant adenovirus injection into the distal section of the right EJV 30 min prior to anastomosis of the CCA and EJV. An equivalent control adenovirus was injected into the right EJV of group B rats prior to anastomosis. The rats in group C received no virus prior to anastomosis and no medicine subsequent to surgery. The group D rats were lavaged with Vatalanib, a VEGF receptor (VEGFR) inhibitor, and the group E rats were lavaged with an equal quantity of saline weekly following surgery. Six rats from groups A-E and one rat from group F were sacrificed in the first, second, fourth and twelfth weeks after surgery for immunohistochemical analysis of VEGF expression and analysis of microvessel density. Cerebral angiography was performed on the remaining rats in each group on the twelfth week after surgery. The results revealed that following transfection with VEGF recombinant adenovirus, angiogenesis in the dura mater of venous hypertensive rats was increased subsequent to the increase in the VEGF expression levels of the brain and dura mater. The rate of DAVF induction by venous hypertension was significantly reduced by the VEGFR antagonist due to reduced angiogenesis in the dura mater. In conclusion, VEGF and its receptor may be important in the formation of venous hypertension-induced DAVFs.

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms

Background and Purpose The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. Materials and Methods In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. Results While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041). Conclusions Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms.

Balloon-assisted superselective microcatheterization for transarterial treatment of cranial dural arteriovenous fistulas: technique and results.

BACKGROUND: In transarterial embolization of anterior cranial fossa and tentorial dural arteriovenous fistula (DAVF), acute angulation of the feeding artery off the internal carotid artery (ICA) may render stable distal catheterization and, therefore, successful transarterial treatment difficult. In some anatomic dispositions, following selection of the feeding artery, subsequent forward force may lead to prolapse of the microcatheter into the ICA rather than advancing it into either the ophthalmic artery or the meningohypophyseal trunk. OBJECTIVE: We describe a technique that facilitates stable positioning of the microcatheter by using a nondetachable balloon to temporally block the ICA distal to the feeding artery to redirect the catheter into the feeder and to prevent the microcatheter from protruding into the parent artery. METHODS: In 8 cases where routine superselective microcatheterization failed, a balloon was used to block the ICA distal to the feeding artery in an attempt to facilitate superselective microcatheterization. The balloon was inflated following selection of the feeding vessel with the microcatheter and was kept inflated while advancing the catheter. RESULTS: Distal stable microcatheter positions could be obtained in all cases, which enabled us to treat the respective DAVFs with a liquid embolic agent. All 8 cases were angiographically cured with penetration of the liquid embolic agent from the distal artery to the proximal vein, and no procedure-related complications occurred. CONCLUSION: The described technique may be a helpful adjunct to gain stable distal microcatheter positions during the transarterial treatment of DAVF. ABBREVIATIONS: DAVF, dural arteriovenous fistula ICA, internal carotid artery SMMU, Second Military Medical University

Morphological Risk Factors for Rupture of Small (<7 mm) Posterior Communicating Artery Aneurysms

BACKGROUND The management of small, unruptured intracranial aneurysms is still controversial. Given the distinctive natural history of aneurysm at different locations, location-specific analysis might be a reasonable approach. This study aimed to investigate morphological discriminators for rupture status by focusing on only posterior communicating artery (PcomA) aneurysms smaller than 7 mm. METHODS In 108 small PcomA aneurysms (68 ruptured, 40 unruptured), clinical and morphological characteristics were compared between the ruptured and unruptured groups. Multivariate logistic regression analysis was performed to determine the independent predictors for the rupture status of small PcomA aneurysms. RESULTS None of the clinical characteristics were significantly different between the ruptured and unruptured groups (P > 0.05). The ruptured group revealed a significantly larger size (P = 0.009), aspect ratio (P = 0.009), size ratio (P = 0.002), dome-to-neck ratio (P = 0.002), inflow angle (P < 0.001), and proportion of bleb formation (P = 0.039). Bottleneck factor (P = 0.154), diameter of PcomA (P = 0.302), and fetal-type PcomA (P = 0.832) showed no significance. With multivariate analyses, size ratio (P = 0.012) and inflow angle (P = 0.001) were shown to be independently associated with the rupture status of small PcomA aneurysms. CONCLUSIONS Morphological characteristics were closely related with the rupture status of small PcomA aneurysms. Size ratio and inflow angle were independent risk factors for rupture and might be useful in clinical risk stratification of small PcomA aneurysms.

Treatment of Supratentorial Spontaneous Intracerebral Hemorrhage Using Image-Guided Minimally Invasive Surgery: Initial Experiences of a Flat Detector CT–Based Puncture Planning and Navigation System in the Angiographic Suite

BACKGROUND AND PURPOSE: The intracerebral hemorrhage drainage through minimally invasive approach is emerging as an alternative for traditional craniotomy, due to its improved survival rate and reduced complication rate. In this study, we investigated the feasibility and safety of a flat detector CT–based puncture planning and navigation system for minimally invasive hematoma drainage on patients with intracerebral hemorrhage. MATERIALS AND METHODS: The minimally invasive hematoma drainage was performed on 21 hypertensive patients with intracerebral hemorrhage in the angiographic suite with the guidance of a flat detector CT–based puncture planning and navigation system. This system is integrated in the angiographic machine, and was used for 1) planning the needle path based on a preprocedural flat detector CT scan, 2) advancing the catheter with real-time fluoroscopic guidance, and 3) confirming the procedure outcome based on an immediate postprocedural flat detector CT. The surgery efficiency, accuracy, and the treatment outcome were measured and compared with the published data. RESULTS: All procedures were successfully completed with the catheter placed 4 ± 1 mm from the planned position. The average surgery time was 40 ± 7 minutes. The volume of the hematoma was reduced to 28 ± 4% of the original volume. The Glasgow Coma Scale score was significantly improved from 10 ± 1 at the admission to 14 ± 1 at the discharge. The Extended Glasgow Coma Scale score also improved from 5 ± 1 at the discharge to 6 ± 1 at the 6-month follow-up. No major complication, rebleeding, and mortality were observed in this study. CONCLUSIONS: This flat detector CT–based needle guidance system provided a feasible, convenient, and safe way to perform the puncture and drainage of brain hematoma in the angiographic suite.