Cerebral aneurysm treatment: modern neurovascular techniques.

Endovascular treatment of cerebral aneurysm continues to evolve with the development of new technologies. This review provides an overview of the recent major innovations in the neurointerventional space in recent years

The 'Sphere': A Dedicated Bifurcation Aneurysm Flow-Diverter Device.

We present flow-based results from the early stage design cycle, based on computational modeling, of a prototype flow-diverter device, known as the 'Sphere', intended to treat bifurcation aneurysms of the cerebral vasculature. The device is available in a range of diameters and geometries and is constructed from a single loop of NITINOL(®) wire. The 'Sphere' reduces aneurysm inflow by means of a high-density, patterned, elliptical surface that partially occludes the aneurysm neck. The device is secured in the healthy parent vessel by two armatures in the shape of open loops, resulting in negligible disruption of parent or daughter vessel flow. The device is virtually deployed in six anatomically accurate bifurcation aneurysms: three located at the Basilar tip and three located at the terminus bifurcation of the Internal Carotid artery (at the meeting of the middle cerebral and anterior cerebral arteries). Both steady state and transient flow simulations reveal that the device presents with a range of aneurysm inflow reductions, with mean flow reductions falling in the range of 30.6-71.8% across the different geometries. A significant difference is noted between steady state and transient simulations in one geometry, where a zone of flow recirculation is not captured in the steady state simulation. Across all six aneurysms, the device reduces the WSS magnitude within the aneurysm sac, resulting in a hemodynamic environment closer to that of a healthy vessel. We conclude from extensive CFD analysis that the 'Sphere' device offers very significant levels of flow reduction in a number of anatomically accurate aneurysm sizes and locations, with many advantages compared to current clinical cylindrical flow-diverter designs. Analysis of the device's mechanical properties and deployability will follow in future publications

Extending the indications of flow diversion to small, unruptured, saccular aneurysms of the anterior circulation.

BACKGROUND AND PURPOSE: Flow diverters are currently indicated for treatment of large and complex intracranial aneurysms. The purpose of this study was to determine whether the indications of flow diversion can be safely extended to unruptured, small, saccular aneurysms (\u3c10 \u3emm) of the anterior circulation. METHODS: Forty patients treated with the pipeline embolization device (PED) were matched in a 1:4 fashion with 160 patients treated with stent-assisted coiling based on patient age, sex, aneurysm location, and aneurysm size. Procedural complications, angiographic results, and clinical outcomes were analyzed and compared. RESULTS: The rate of periprocedural complications was 5% in the PED group and 3% in the stent-coil group (P=0.7). In multivariable analysis, increasing age was the only predictor of complications. At follow-up, a higher proportion of aneurysms treated with PED (80%) achieved complete obliteration compared with stent-coiled aneurysms (70%) but the difference did not reach statistical significance (P=0.2). In multivariable analysis, increasing aneurysm size and aneurysm location were predictors of nonocclusion. The rate of favorable outcome (modified Rankin Scale, 0-2 and modified Rankin Scale, 0-1) was similar in the PED group and the coil group. CONCLUSIONS: The PED was associated with similar periprocedural risks, clinical outcomes, and angiographic results compared with stent-assisted coiling. These findings suggest that the indications of PED can be safely extended to small intracranial aneurysms that are amenable to conventional endovascular techniques. Larger studies with long-term follow-up are necessary to determine the optimal treatment that leads to the highest rate of obliteration and best clinical outcomes

Recollections of My Research in Developing the Heart-Lung Machine at Jefferson Medical College

A personal memoir written by Dr. Bernard J. Miller about his introduction to and interest in medical research as well as his experiences working on the heart-lung machine. He focuses specifically on his working relationship with John H. Gibbon, Jr., the development of a viable oxygenator and ventilator, and early testing of the machine on animal

Parent artery reconstruction for large or giant cerebral aneurysms using a Tubridge flow diverter (PARAT): study protocol for a multicenter, randomized, controlled clinical trial

BACKGROUND: The treatment of large (10-25 mm) or giant (≥25 mm) cerebral aneurysms remains technically challenging, with a much higher complication and recanalization rate than that is observed for smaller aneurysms. The use of a flow diverter seems to facilitate the treatment of this special entity. In a previous single-center prospective study approved by the Ethics Committee and China Food and Drug Administration (CFDA), we obtained promising results, showing remarkable safety and effectiveness for the Tubridge flow diverter. Nevertheless, the previous study may have been limited by biases due to its single-center design and limited number of subjects. Furthermore, although various articles have reported durable results from treating aneurysms using flow diverters, increasing questions have arisen about this form of treatment. Thus, prospective, multiple-center, randomized trials containing more subjects are needed. METHODS/DESIGN: This study is a multicenter, randomized, controlled clinical trial comparing clinical outcomes for patients with unruptured large/giant intracranial aneurysms treated with either conventional stent-assisted coiling or flow diverter implantation. A total of 124 patients who fulfill the inclusion and exclusion criteria will be randomized into either a treatment group or a control group in the ratio of 1:1. The treatment group will receive Tubridge implantation alone or combined with bared coils, and the control group will be treated with stent-assisted coiling (bare coils). The primary endpoint will be the complete occlusion rate at 6-month follow-up. Secondary endpoints include the immediate technique success rate, overall mortality, adverse events (ischemic stroke or intracranial bleeding) within 30 days, 90 days and 1 year post-operation, and the rate of intra-stent stenosis and thrombosis 6 months post-operation. DISCUSSION: This prospective trial may provide more information on the safety and efficacy of the Tubridge flow diverter and may potentially change the strategy for treatment of large or giant aneurysms. TRIAL REGISTRATION: The trial is registered on the Chinese Clinical Trial Registry: ChiCTR-TRC-1300312

Flow-diversion panacea or poison?

Endovascular therapy is now the treatment of choice for intracranial aneurysms (IAs) for its efficacy and safety profile. The use of flow diversion (FD) has recently expanded to cover many types of IAs in various locations. Some institutions even attempt FD as first line treatment for unruptured IAs. The most widely used devices are the pipeline embolization device (PED), the SILK flow diverter (SFD), the flow redirection endoluminal device (FRED), and Surpass. Many questions were raised regarding the long-term complications, the optimal regimen of dual antiplatelet therapy, and the durability of treatment effect. We reviewed the literature to address these questions as well as other concerns on FD when treating IAs

Stent-assisted reconstructive endovascular repair of intracranial aneurysms: long-term clinical and angiographic follow-up

Abstract Background and Purpose: The development of self-expanding stents dedicated to intracranial use has significantly widened the applicability of endovascular therapy to many intracranial aneurysms. The purpose of this study was to report the angiographic and clinical outcomes of wide-necked intracranial aneurysms treated with stent. Methods: Between January 2007 and October 2011 we deployed 22 stents in 20 patients with wide-necked cerebral aneurysms. Inclusion criteria restricted the group to adult patients with wide-necked intracranial aneurysms (ruptured and unruptured lesions). Immediate post-procedural angiographic studies were performed to evaluate successful occlusion of the aneurysm as well as patency of the parent vessel. We assessed long term angiography follow-up to detect in-stent stenosis, progressive thrombosis, recurrence and need for retreatment. Clinical outcome was assessed with the modifing Ranking Scale (mRS). Results: Technical success was obtained in all 22 (100%) cases. Angiography immediately after treatment procedure showed complete occlusion in 7 aneurysms (35%), neck remnant in 11 (55%), incomplete occlusion in 1 (5%) and partial occlusion in 1 (5%). During the endovascular embolization procedure no rupture of the sac or bleeding complication occurred; none of the patients needed undergoing surgical crossover. Procedure-related adverse events occurred in one (5%) patient: a brachial artery pseudoaneurysm. Three (15%) patients had neurological complications after procedure, whose 1 (5%) transitory complication spontaneusly resolved. Two patients (10%), had acute complete in-stent thrombosis which resolved after intraarterial administration of abciximab and placement of a new stent in-stent. Of the 20 patients treated with stent deployment, a follow-up imaging study was available in all 19 surviving patients (95%) at an average of 16.2 months (range, 6 to 50 months). The first follow-up DSA, compared with initial angiography, showed no changes in 14 aneurysms (73.7%), progressive thrombosis in 3 (15.7%), and major recurrence in 2 (10.5%). The overall rate of succesful procedure to 6 months is 89.5%; there was 1 case of asintomatic moderate endothelial hyperplasia. The further follow-up imaging study, showed no changes in 17 (89.5%) of the 19 surviving patients, 1 progressive thrombosis and 1 minor recurrence. One month- and long term (average of 16.2 months; range, 6 to 50 months) clinical follow-up showed no worsening in the mRS in 18 (90%) of 20 patients, 1 (5%) mRS 2 and 1 (5%) mRS 6. All the survived patients are alive and we did not observe periprocedural or long-term intracranial bleeding events or symptomatic stent related stenosis/occlusion complication. Conclusions: Our findings suggest that the endovascular treatment of intracranial aneurysms by stenting is feasible, effective and safe; follow-up results proved intact parent arteries and stable occlusion rates in the majority of treated aneurysms. Nevertheless, long-term data on safety and efficacy and larger patient groups are necessary

Intracranial Stents Past, Present and the Future Trend: Stents Made with Nano-particle or Nanocomposite Biomaterials

Stroke or cerebral vascular accidents are among the leading causes of death in the world. With the availability of Digital Subtraction Angiography, transluminal angioplasty has become feasible in many situations and the role of intracranial stents is becoming ever more important in the management of cerebral vascular diseases. In current review, we outline the chronological development of various stents namely; balloon expandable stent, self-expandable open cell stent, self-expandable close cell stent and the flow diverting stent. Further we discuss their advantages and limitations in terms of stent migration, thromboemboli, damage to vessels during procedure, in-stent stenosis and hyper-perfusion damage. We also discuss the importance of in-situ endothelialization, controlled expandability and hemodynamic manipulation in stent design. Further, we summarized the role and need for further development in the areas of bio-compatible materials, endothelial progenitor cell capture technique, bio-functionalized-magnetic-nano-particles and nanotechnology which are significant in intracranial stent development

Carotid artery stenting: an update

In patients with carotid disease, the purpose of carotid artery revascularization is stroke prevention. For >50 years, carotid endarterectomy has been considered the standard treatment for severe asymptomatic and symptomatic carotid stenoses. Carotid artery stenting (CAS) has emerged in the last 15 years as minimally invasive alternative to surgery. However, the value of the endovascular approach in the management of carotid disease patients remains highly controversial. The aims of this review are to elucidate the current role of CAS, to describe the major technology advancements in the field, and to speculate about the future of this therap