Consecutive Endovascular Treatment of 20 Ruptured Very Small (<3 mm) Anterior Communicating Artery Aneurysms.

BACKGROUND: Small aneurysms located at the anterior communicating artery carry significant procedural challenges due to a complex anatomy. Recent advances in endovascular technologies have expanded the use of coil embolization for small aneurysm treatment. However, limited reports describe their safety and efficacy profiles in very small anterior communicating artery aneurysms. OBJECTIVE: We sought to review and report the immediate and long-term clinical as well as radiographic outcomes of consecutive patients with ruptured very small anterior communicating artery aneurysms treated with current endovascular coil embolization techniques. METHODS: A prospectively maintained single-institution neuroendovascular database was accessed to identify consecutive cases of very small (<3 mm) ruptured anterior communicating artery aneurysms treated endovascularly between 2006 and 2013. RESULTS: A total of 20 patients with ruptured very small (<3 mm) anterior communicating artery aneurysms were consecutively treated with coil embolization. The average maximum diameter was 2.66 ± 0.41 mm. Complete aneurysm occlusion was achieved for 17 (85%) aneurysms and near-complete aneurysm occlusion for 3 (15%) aneurysms. Intraoperative perforation was seen in 2 (10%) patients without any clinical worsening or need for an external ventricular drain. A thromboembolic event occurred in 1 (5 %) patient without clinical worsening or radiologic infarct. Median clinical follow-up was 12 (±14.1) months and median imaging follow-up was 12 (±18.4) months. CONCLUSION: This report describes the largest series of consecutive endovascular treatments of ruptured very small anterior communicating artery aneurysms. These findings suggest that coil embolization of very small aneurysms in this location can be performed with acceptable rates of complications and recanalization.

Endovascular reconstruction for progressively worsening carotid artery dissection.

BACKGROUND: Carotid artery dissection is an important cause of stroke in young patients. Selection criteria for endovascular repair have not been well defined and limited data exist on long-term outcomes of stent reconstruction. OBJECTIVE: To report the immediate and long-term clinical and radiographic outcomes of patients treated with stent placement for progressively worsening symptomatic carotid arterial dissection despite antithrombotic therapy. METHODS: A single institution neuro-endovascular database was accessed to identify consecutive cases in which carotid artery dissection was treated with endovascular repair between 2006 and 2012. Clinical, demographic, radiographic, and procedural data were obtained through chart review. RESULTS: A total of 22 patients were identified and included 27 carotid artery dissection repairs with stent implantation. The mean age was 43 years (±8.7) with 13 patients being women. Traumatic dissections were seen in 9 (40.9%) patients and spontaneous dissections in 13 (59.1%) patients. All patients were symptomatic and were started on antithrombotic therapy on diagnosis. Most common indications for treatment included recurrent ischemia despite antithrombotic therapy in 15 (55.5%) arteries and enlarging dissecting aneurysm in 4 (14.8%) arteries. Mean degree of stenosis was 79.1%. Mean number of stents used was 1.88 (range 1-4). There was 1 (4.5%) asymptomatic peri-procedural thromboembolic event. Median clinical follow-up was 14 months (range 3-40) and median imaging follow-up was 14 months (range 3-38). There was 1 (4.5%) case of recurrent transient ischemic attack. There was no death, significant restenosis or stroke in the territory of the treated vessel during the duration of the follow-up. CONCLUSIONS: Endovascular stent reconstruction for the treatment of selected patients with progressively worsening carotid dissection despite medical management is feasible with acceptable immediate and long-term clinical and radiographic outcomes. To be able to draw more robust conclusions, further evaluation with larger number of patients and longer follow-up is needed.

Predictors and Outcomes Associated with Rescue Therapy in SWIFT.

INTRODUCTION: In the Solitaire With the Intention For Thrombectomy (SWIFT) trial, rescue therapy was used when the Solitaire or Merci device was unable to restore vessel patency. Markers for nonrecanalization in acute stroke have been reported for intravenous tissue plasminogen activator; however, similar predictors are not known for endovascular therapy. We sought to identify predictors and outcomes associated with rescue therapy in the SWIFT trial. METHODS: Rescue therapy included the use of an alternative device, agent, or maneuver following failure to recanalize with three retrieval attempts using the initial device. Clinical, angiographic, and demographic data was reviewed. RESULTS: Among a total of 144 patients enrolled, 43 (29.9%) required rescue therapy. We used the same baseline demographics for patients with and without rescue therapy. Rescue therapy was used in a higher percentage of patients randomized to the Merci group compared with the Solitaire group (43 vs. 21%, p = 0.009). Patients with rescue therapy experienced a longer recanalization time (p < 0.001), a lower percentage of successful recanalization (p < 0.001), and a lower percentage of good outcome (p = 0.009). In multivariate analysis, patients randomized to the Merci group (OR 3.99, 95% CI 1.58, 10.10) and age >80 years (OR 3.51, 95% CI 1.06, 11.64) were predictors of rescue therapy. CONCLUSIONS: Merci treatment group and age were predictors of rescue therapy, while a trend toward an increased need of rescue therapy was observed with hypertension and proximal clot location. Rescue therapy was associated with fewer good outcomes. These findings may reflect targets for improvement in endovascular therapy.

The natural history of vertebral artery origin stenosis.

BACKGROUND: We sought to determine the long-term survival and natural history of vertebral artery origin stenosis (VAOS) as it relates to stroke. METHODS: We retrospectively reviewed clinical data on patients admitted at a single institution for possible stroke between 2004 and 2007 and selected subjects who underwent angiography of the neck. We classified VAOS subjects as having "moderate" to "severe" (≥50%) occlusion. Age-, sex-, and race-matched control subjects with no evidence of VAOS on angiography were selected from our study population. Long-term follow-up data were collected and death certificates were searched for comparison among cases and controls. A Kaplan-Meier curve was plotted based on time to event (stroke or death). RESULTS: Fifty-eight of the 358 subjects were found to have VAOS (16.2%). Four subjects were excluded because of stenting; therefore, 54 cases and 54 matched controls were included for long-term follow-up analysis. In our study population, we calculated that the relative risk of having a stroke or dying in patients with VAOS was 6 times that of patients without VAOS (P < .02). The observed 5-year survival rate for patients with VAOS was 67% (36/54) compared to 89% (48/54) in control subjects (P < .01). CONCLUSIONS: Patients with VAOS are at a significantly higher risk of having a stroke or dying. Subsequent prospective, multicenter studies are needed to validate our results.

Identifying delays to mechanical thrombectomy for acute stroke: onset to door and door to clot times.

Outcomes from endovascular therapy for acute stroke are time dependent. Delays in the administration of this therapy have not been extensively studied and no performance benchmarks have been established. There are limited data on the complex factors that can affect these delays. In this review, we discuss the existing literature on the delays involved in endovascular therapy and have presented them as prehospital and inhospital factors. Some of these factors are common to intravenous thrombolysis; in addition, there are some that are unique to endovascular therapy. These include the awareness of the first responders, emergency medical services, interhospital transfer and triage systems, activation of the endovascular team, complex imaging decisions, and intraprocedural delays. A thorough understanding of these delays can help identify areas of improvement which may affect clinical outcomes.

Safety and predictors of aneurysm retreatment for remnant intracranial aneurysm after initial endovascular embolization.

INTRODUCTION: Aneurysmal subarachnoid hemorrhage (SAH) is a rare but devastating form of stroke. Endovascular therapy has been criticized for its higher rate of recanalization and retreatment. The safety and predictors of retreatment are unknown. We report the clinical outcomes, imaging outcomes and predictors for aneurysm retreatment after initial endovascular embolization. METHOD: We identified patients who underwent endovascular retreatment from July 2005 through November 2011. Aneurysm and patient data were collected. Periprocedural complications were reported as intraoperative perforation (IOP) or thromboembolic event (TEE). Aneurysm and patient characteristics were compared between aneurysms requiring retreatment and those not requiring retreatment to evaluate aneurysm retreatment predictors. RESULTS: A total of 111/871 (13%) aneurysms underwent retreatment. Two (0.2%) were retreated for recurrent acute SAH, 82 (74%) aneurysms were located in the anterior circulation, 47 (42%) required stent and 5 (5%) required balloon assist during retreatment. There were a total of 5 (5%) IOP and 6 (5%) TEE from which 2 (2%) and 1 (1%) were symptomatic, respectively. Overall symptomatic events rate were 2.7%. Patients were followed up for an average of 15±14 months. Seven (0.8%) aneurysms required a second retreatment without any recurrent SAH. Multivariable analysis revealed an OR for aneurysms requiring retreatment of 2.965 for aneurysms presenting as aneurysmal SAH, 1.791 for aneurysms in the posterior circulation and 1.053 for aneurysms with large dome size. CONCLUSIONS: Aneurysm retreatment is a safe option without a significant increase in morbidity or mortality. SAH, posterior circulation aneurysms and larger aneurysm dome size are predictors of aneurysms requiring retreatment.

The diagnosis and management of brain arteriovenous malformations.

Although uncommon in the general population, cerebral arteriovenous malformations (AVMs) can pose a significant health risk if a rupture occurs. Advances in noninvasive imaging have led to an increase in the identification of unruptured AVMs, presenting new challenges in management, given their poorly understood natural history. Over the past decade, there have been significant developments in the management and treatment of intracranial AVMs. This article discusses the pathophysiology, natural history, clinical presentations, and current treatment options, including multimodal approaches, for these vascular malformations.

Angiographic lumen changes associated with oversized intracranial stent implantation for aneurysm treatment.

BACKGROUND: The effect of oversized intracranial stent implantation, and potential excessive neointimal hyperplasia from the chronic outward radial force, has not been reported. We sought to compare the angiographic narrowing associated with implantation of oversized stents. METHODS: We reviewed an aneurysm database and identified patients treated with stent-assisted embolization involving a vessel size transition. Demographics and lesion characteristics were extracted. The relationship between lumen diameter and stent oversizing was compared. RESULTS: Twenty vessels were identified in 18 patients, providing 80 paired data points. Mean follow-up time was 8 months (SD 6). The average oversizing in the smaller diameter parent vessel landing-zone was 1.75 mm. Mean change in lumen size from pre-stent implantation was not significantly different for any of the four sites. There was a significant difference in change of lumen size at the stent tines when compared with the respective mid-stent segment for both the proximal (P = 0.02) and distal (P = 0.0004) landing zones. CONCLUSIONS: A small significant lumen loss occurs at stent tines when compared to midstent struts. However, there is no overall significant stenosis from highly oversized stents. Persistent luminal gain from the oversized stent radial force likely predominates over any neointimal hyperplasia.

Surveillance imaging after intracranial stent implantation: non-invasive imaging compared with digital subtraction angiography.

BACKGROUND: Digital subtraction angiography (DSA) is the gold standard imaging for detection of in-stent restenosis (ISR) but there is limited literature on optimal non-invasive surveillance imaging. In this study, the ability of CT angiography (CTA) and MR angiography (MRA) compared with DSA in recognizing ISR was assessed. METHODS: A single center database of patients treated with stent implantation for ICAD was accessed. All patients who underwent follow-up imaging with DSA paired with either MRA or CTA within 30 days were included. Two angiography readers and two non-invasive imaging readers measured restenosis with a submillimeter digital caliper. ISR was categorized as: none/minimal, mild (<50%), moderate (≥50-70%) or severe (≥70%). Analysis was performed with weighted κ statistics. RESULTS: 17 cases of individual stents that underwent surveillance imaging with paired DSA and CTA and five stents with paired DSA and MRA were identified. Of those undergoing DSA and CTA, inter-reader agreement produced κ=0.68 (95% CI 0.40 to 0.95) for DSA and κ=0.75 (95% CI 0.55 to 0.95) for CTA. Agreement across CTA and DSA was κ=0.36 (95% CI 0.26 to 0.52). Of those undergoing DSA and MRA, inter-reader agreement produced κ=0.71 (95% CI 0.27 to 1.00) for DSA and κ=1.00 (95% CI 1.00 to 1.00) for MRA. Agreement across MRA and DSA was κ=0.34 (95% CI 0.18 to 0.51). CONCLUSIONS: Good inter-reader agreement exists within DSA, CTA and MRA. However, when comparing non-invasive imaging (CTA and MRA) with DSA, only fair agreement exists. These data suggest that CTA and MRA are not comparable to DSA for evaluation of ISR.

Cerebral arteriovenous malformation diagnosis and management.

Arteriovenous malformations of the brain can carry considerable morbidity and mortality in the setting of rupture. The complex angioarchitecture and hemodynamic alteration requires careful consideration in diagnostic and management approaches. In this review, the authors define the pathophysiology, outline diagnostic methods, and highlight current management approaches.

Idiopathic Intracranial Hypertension. A Systematic Analysis of Transverse Sinus Stenting.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a disorder characterized by signs and symptoms of increased intracranial pressure without structural cause seen on conventional imaging. Hallmark treatment after failed medical management, has been CSF shunting or optic nerve fenestration with the goal of treatment being preservation of vision. Recently, there have been multiple case reports and case series on dural sinus stenting for this disorder. OBJECTIVE: We aim to review all published cases and case series of dural sinus stenting for IIH, with analysis of patient presenting symptoms, objective findings (CSF pressures, papilledema, pressure gradients across dural sinuses), follow-up of objective findings, and complications. METHODS: A Medline search was performed to identify studies meeting pre-specified criteria of a case report or case series of patients treated with dural sinus stent placement for IIH. The manuscripts were reviewed and data was extracted. RESULTS: A total of 22 studies were identified, of which 19 studies representing 207 patients met criteria and were included in the analysis. Only 3 major complications related to procedure were identified. Headaches resolved or improved in 81% of patients. Papilledema improved the (172/189) 90%. Sinus pressure decreased from an average of 30.3 to 15 mm Hg. Sinus pressure gradient decreased from 18.5 (n=185) to 3.2 mm Hg (n=172). Stenting had an overall symptom improvement rate of 87%. CONCLUSION: Although all published case reports and case series are nonrandomized, the low complication and high symptom improvement rate make dural sinus stenting for IIH a potential alternative surgical treatment. Standardized patient selection and randomization trials or registry are warranted.

Complications of endovascular therapy for acute ischemic stroke and proposed management approach.

Over the past decade, endovascular therapy has emerged as a promising therapeutic approach for select patients with acute ischemic stroke. However, the morbidity, mortality, and complication rates in intra-arterial recanalization trials are higher than in the National Institute of Neurological Disorders and Stroke trial of IV tissue plasminogen activator. This review discusses common complications associated with endovascular therapy for acute ischemic stroke, avoidance of complications, and management of some of the common complications.

Developing practice recommendations for endovascular revascularization for acute ischemic stroke.

Guidelines have been established for the management of acute ischemic stroke; however, specific recommendations for endovascular revascularization therapy are lacking. Burgeoning investigation of endovascular revascularization therapies for acute ischemic stroke, rapid device development, and a diverse training background of the providers performing the procedures underscore the need for practice recommendations. This review provides a concise summary of the Society of Vascular and Interventional Neurology endovascular acute ischemic stroke roundtable meeting. This document was developed to review current clinical efficacy of pharmacologic and mechanical revascularization therapy, selection criteria, periprocedure management, and endovascular time metrics and to highlight current practice patterns. It therefore provides an outline for the future development of multisociety guidelines and recommendations to improve patient selection, procedural management, and organizational strategies for revascularization therapies in acute ischemic stroke.

Venous sinus pulsatility and the potential role of dural incompetence in idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension (IIH) remains a poorly understood and therapeutically challenging disease. Enthusiasm has emerged for endovascular therapy with stent reconstruction of dural sinus narrowing; however, a complete understanding of the hydrodynamic dysequilibrium is lacking. OBJECTIVE: To review and characterize catheter manometry findings including pulsatility changes within the venous sinuses in IIH. METHODS: Cases of venous sinus stent implantation for IIH were retrospectively reviewed. RESULTS: Three cases of venous sinus stent implantation for treatment of IIH are reported. All cases demonstrated severe narrowing (>70%) within the transverse sinus and a high pressure gradient across the lesion (>30 mm Hg). Stent implantation resulted in pulsatility attenuation, correction of pressure gradient, and improvement of flow. CONCLUSION: We report the finding of high venous sinus pulsatility attenuation after stent implantation for dural sinus narrowing and propose the hypothesis that this finding is a marker of advanced dural sinus incompetence. This characteristic may be useful in identifying patients who would benefit from endovascular stent remodeling.

Multimodal endovascular reperfusion therapies: adjunctive antithrombotic agents in acute stroke.

Pharmacologic and mechanical endovascular acute ischemic stroke therapy aims to recanalize occluded cerebral vessels to achieve improved clinical outcome. Several limitations to achieving this goal have been identified; one of the least discussed challenges in the literature is reocclusion. The intraprocedure and periprocedural roles of anticoagulation and antiplatelet agents in preventing reocclusion are unclear. In this review, the role of antiplatelet and anticoagulation agents as an adjunctive to acute ischemic stroke endovascular revascularization therapy is discussed.

Pericallosal artery aneurysm treatment using Y-configuration stent-assisted coil embolization: a report of four cases.

BACKGROUND: Pericallosal artery aneurysms at the bifurcation represent a special endovascular technical challenge given their distal location, commonly wide-neck morphology, small parent vessel diameter and potentially high recurrence rate after coiling given the bifurcation location. Y-configuration stent-assisted coil embolization techniques have been reported for the treatment of wide-neck aneurysms located at other vascular bifurcations and only rarely with A2 bifurcation aneurysms. METHODS: A neurointerventional database was reviewed for identification of all cases of A2 bifurcation aneurysms that were treated with Y-stent configuration. The authors report clinical, technical and outcome data on four patients with pericallosal aneurysms who were treated with a Y-configuration stent-assisted coil embolization technique. RESULTS: A Y-configuration stent placement in the anterior cerebral artery/A2 bifurcation was successfully achieved in all four patients without significant technical difficulties. One patient presented with a previously ruptured and partially treated aneurysm and three patients with incidentally found aneurysms. All four patients had a Y-configuration stent placement in one setting. The Y-configuration allowed for complete occlusion of all four aneurysms with no recurrence or arterial occlusion on mean angiographic follow-up of 13.5 months (6-28). CONCLUSION: Treating wide-neck pericallosal artery aneurysms at the bifurcation with Y-configuration stent placement is feasible and effective. This technique may be considered as a therapeutic option for wide-neck aneurysms that pose a difficult technical challenge.