Erik F. Hauck

First Food and Drug Administration-Approved Prospective Trial of Primary Intracranial Stenting for Acute Stroke SARIS (Stent-Assisted Recanalization in Acute Ischemic Stroke)

Background and Purpose— Acute revascularization is associated with improved outcomes in ischemic stroke patients. However, it is unclear which method of intraarterial intervention, if any, is ideal. Numerous case series and cardiac literature parallels suggest that acute stenting may yield high revascularization levels with low associated morbidity. We therefore conducted a Food and Drug Administration-approved prospective pilot trial to evaluate the safety of intracranial stenting for acute ischemic stroke. Methods— Eligibility criteria included presentation ≤8 hours after stroke onset, age 18 years or older, National Institutes of Health Stroke Scale score ≥8, angiographic demonstration of focal intracerebral artery occlusion ≤14 mm, and either contraindication to intravenous tissue plasminogen activator or failure to improve 1 hour after intravenous tissue plasminogen activator administration. Exclusion criteria included known hemorrhagic diathesis or coagulopathy, platelet count <100 000, intracranial hemorrhage, blood glucose level of <51 mg/100 mL, or CT perfusion imaging demonstrating more than one-third at-risk territory with nonsalvageable brain (low cerebral blood volume). Data are presented as mean±SD. Results— Twenty patients were enrolled (mean age, 63±18 years;14 women). Mean presenting National Institutes of Health Stroke Scale was 14±3.8 (median 13). Presenting thrombolysis in myocardial infarction score was 0 (85% of patients) or 1 (15%). Recanalization to thrombolysis in myocardial infarction score of 3 (60% of patients) or 2 (40% of patients; P<0.0001) was achieved. One (5%) symptomatic and 2 (10%) asymptomatic intracranial hemorrhages occurred. At 1-month follow-up, a modified Rankin scale score of ≤3 was achieved in 12 of 20(60%) patients and a modified Rankin scale score of ≤1 was achieved in 9 of 20 (45%) patients. Conclusion— This Food and Drug Administration-approved prospective study suggests primary intracranial stenting for acute stroke may be a valuable addition to the stroke treatment armamentarium.

Size Ratio Correlates With Intracranial Aneurysm Rupture Status A Prospective Study

Background and Purpose— The prediction of intracranial aneurysm (IA) rupture risk has generated significant controversy. The findings of the International Study of Unruptured Intracranial Aneurysms (ISUIA) that small anterior circulation aneurysms (<7 mm) have a 0% risk of subarachnoid hemorrhage in 5 years is difficult to reconcile with other studies that reported a significant portion of ruptured IAs are small. These discrepancies have led to the search for better aneurysm parameters to predict rupture. We previously reported that size ratio (SR), IA size divided by parent vessel diameter, correlated strongly with IA rupture status (ruptured versus unruptured). These data were all collected retrospectively off 3-dimensional angiographic images. Therefore, we performed a blinded prospective collection and evaluation of SR data from 2-dimensional angiographic images for a consecutive series of patients with ruptured and unruptured IAs. Methods— We prospectively enrolled 40 consecutive patients presenting to a single institution with either ruptured IA or for first-time evaluation of an incidental IA. Blinded technologists acquired all measurements from 2-dimensional angiographic images. Aneurysm rupture status, location, IA maximum size, and parent vessel diameter were documented. The SR was calculated by dividing the aneurysm size (mm) by the average parent vessel size (mm). A 2-tailed Mann-Whitney test was performed to assess statistical significance between ruptured and unruptured groups. Fisher exact test was used to compare medical comorbidities between the ruptured and unruptured groups. Significant differences between the 2 groups were subsequently tested with logistic regression. SE and probability values are reported. Results— Forty consecutive patients with 24 unruptured and 16 ruptured aneurysms met the inclusion criteria. No significant differences were found in age, gender, smoking status, or medical comorbidities between ruptured and unruptured groups. The average maximum size of the unruptured IAs (6.18±0.60 mm) was significantly smaller compared with the ruptured IAs (7.91±0.47 mm; P=0.03), and the unruptured group had significantly smaller SRs (2.57±0.24 mm) compared with the ruptured group (4.08±0.54 mm; P<0.01). Logistic regression was used to evaluate the independent predictive value of those variables that achieved significance in univariate analysis (IA maximum size and SR). Using stepwise selection, only SR remained in the final predictive model (OR, 2.12; 95% CI, 1.09 to 4.13). Conclusion— SR, the ratio between aneurysm size and parent artery diameter, can be easily calculated from 2-dimensional angiograms and correlates with IA rupture status on presentation in a blinded analysis. SR should be further studied in a large prospective observational cohort to predict true IA risk of rupture.

Use of a vascular reconstruction device to salvage acute ischemic occlusions refractory to traditional endovascular recanalization methods.

OBJECT Acute revascularization has been associated with improved stroke outcomes. The Prolyse in Acute Cerebral Thromboembolism (PROACT II) trial achieved recanalization rates of 66%. The Multi Mechanical Embolus Removal in Cerebral Ischemia (Multi MERCI) trial achieved recanalization in 70% of patients. However, these interventional tools are not always successful. The Enterprise vascular reconstruction device was recently introduced for treatment of cerebral aneurysms previously untreatable with endovascular techniques. The authors evaluated a multicenter experience using this stent as a salvage revascularization tool for acute stroke treatment. METHODS Four medical centers participated in a retrospective review of endovascularly treated patients with acute stroke for cases treated with the Enterprise stent after routine interventions had been unsuccessful. Data collected included preprocedure information, intraprocedure findings, and outcomes. RESULTS Twenty patients with acute stroke (mean age 61.6 +/- 22 years) were treated with the Enterprise stent. Ten patients received intravenous recombinant tissue plasminogen activator before catheter intervention, without improvement. Intraarterial interventions attempted unsuccessfully before Enterprise deployment included the Merci retriever (12 patients), angioplasty (7 patients), glycoprotein IIb-IIIa inhibitor administration (12 patients), intraarterial nitroglycerin (1 patient), Wingspan stent deployment (3 patients), and Xpert stent deployment (1 patient). The mean preintervention National Institutes of Health Stroke Scale (NIHSS) score was 17 +/- 6 (median 17). All patients presented with a Thrombolysis in Myocardial Infarction (TIMI) score of 0 or 1. Revascularization was achieved in all patients (75% with a TIMI score of 3, 25% with a TIMI score of 2). Improvement (> or = 4 points on the NIHSS) was documented in 75% of patients. Mean NIHSS improvement from intervention to discharge was 8 +/- 7 points (median 9 points). CONCLUSIONS These preliminary data suggest a potential benefit to the use of the Enterprise stent when routine intervention methods fail.

Clipping of very large or giant unruptured intracranial aneurysms in the anterior circulation: An outcome study - Clinical article

OBJECT Patients with very large or giant unruptured intracranial aneurysms present with ischemic stroke and progressive disability. The aneurysm rupture risk in these patients is extreme-up to 50% in 5 years. In this study the authors investigated the outcome of surgical treatment for these very large aneurysms in the anterior circulation. METHODS Clinical data on 62 patients who underwent surgery for unruptured aneurysms (20-60 mm) between 1998 and 2006 were reviewed. RESULTS Complete aneurysm occlusion (100%) was achieved in 90% of cases, near complete occlusion (90-99%) in 5%. The surgical risk in patients younger than 50 years of age was 8% (Glasgow Outcome Scale score of 1 or 3 within 1 year after surgery). In older patients, the risk increased with advancing age. CONCLUSIONS The treatment of very large or giant unruptured intracranial aneurysms is hazardous and complex and thus best performed only at major cerebrovascular centers with an experienced team of neurosurgeons, interventional neuroradiologists, neurologists, and neuroanesthesiologists. Surgery, with acceptable risks and excellent occlusion rates, is typically the treatment of choice in patients younger than 50 years of age. In older patients, the benefits of endovascular treatment versus surgery versus no treatment must be carefully weighed individually. Minimizing temporary occlusion and the consequent use of intraoperative angiography may help reduce surgical complications.

Endovascular stent therapy for extracranial and intracranial carotid artery dissection: single-center experience

OBJECT The objective of this study was to evaluate endovascular stent therapy for carotid artery dissections (CADs). METHODS Retrospective review of data at Millard Fillmore Gates Hospital identified 43 patients with 44 CADs (intracranial and/or extracranial) treated with carotid artery (CA) stent placement between January 2000 and June 2009. RESULTS Thirty-two CADs were spontaneous and 12 were traumatic; 35 were symptomatic. Lesion locations included the extracranial internal CA (ICA; 24 cases), extracranial ICA with common CA involvement (4 cases), and extracranial ICA-intracranial ICA (16 cases). Carotid artery occlusion was 100% in 15 cases (34.1%), 99% in 6 cases (13.6%), 70%-98% in 13 cases (29.5%), and < 70% in 10 cases (22.7%). Five patients suffered pseudoaneurysms. Stent deployment was successful in 43 (97.7%) of 44 cases. The mean pretreatment score on the National Institutes of Health Stroke Scale was 6.2 ± 6.2. Recanalization (Thrombolysis in Myocardial Infarction Grade 2 or 3) was accomplished for 42 lesions (95.5%). Four patients demonstrated residual parent vessel stenosis (10%-50% in severity). Procedure-related complications occurred in 7 patients and included middle cerebral artery embolism (1 patient), intracranial hemorrhage (2 patients), worsening of dissection (1 patient), stent malpositioning (1 patient), embolic protection filter overload (1 patient), and filter retrieval device fracture (1 patient). Only 2 of these complications caused permanent deficits: the embolism caused a minor but permanent neurological deficit, and 1 intracranial hemorrhage was fatal. At discharge, 36 patients (83.7%) had modified Rankin Scale scores of 0-2 (favorable outcome). During the follow-up interval (mean 19.2 months, range 4-92 months), no patient suffered a new stroke and 1 patient died secondary to preexisting chronic renal failure. In 20 patients with angiographic follow-up, permanent resolution of the dissection was noted in 90.5%; 2 lesions (9.5%) required retreatment. CONCLUSIONS Endovascular stent-assisted repair of extra- and intracranial CAD was safe and effective in this experience and can be recommended for selected patients. In particular, patients with symptomatic CADs that are not responsive to medical therapy should be considered for interventional treatment.

Stent/coil treatment of very large and giant unruptured ophthalmic and cavernous aneurysms.

BACKGROUND Treatment of VLGUIA remains a challenge. To reduce mass effect and achieve complete occlusion, open surgery has been our favored treatment. However, endovascular therapy is preferred for lesions in the cavernous sinus or for older patients with complicating medical problems. The goal of this study is to investigate outcome of stent and/or coil treatment of VLGUIA. METHODS Beginning in 2002, the neuroform stent has been available to the University of Texas Southwestern Medical Center in Dallas. Since then until 2006, 15 patients were treated for VLGUIA with stenting and/or coiling at this institution. These 15 patients were used for a retrospective analysis in this study. RESULTS Median patient age was 65 years, median aneurysm size was 27 mm (20-37 mm), and median follow-up time was 22 months. Eight aneurysms were localized in the cavernous sinus and 7 at the ophthalmic segment of the internal carotid artery. Four aneurysms were completely occluded (100%); 3 aneurysms, nearly complete (90%-99%); and 8 aneurysms, partial (<90% occlusion). Twelve patients required retreatment. Final GOS was 1 (good recovery) in 11 patients, 2 (moderate disability) in 3 patients, and 3 (severely disabled) in 1 patient. No patient died or deteriorated. CONCLUSIONS Stent/coil management of VLGUIA is constantly evolving. Current treatment results are promising, with very low morbidity/mortality. Disadvantage is the frequent persistence of residual aneurysm.

Temporary Endovascular Bypass: A Novel Treatment for Acute Stroke

SUMMARY: Intracranial stent placement is emerging as an effective treatment for acute stroke. As a means to avoid stent-associated complications and capitalize on stent-placement-related advantages, the concept of a “temporary endovascular bypass” (TEB) for stroke therapy was recently reported. In this technique, a stent is temporarily deployed for instant recanalization. Once sufficient flow is established to maintain vessel patency, the stent is recaptured and withdrawn. We report a second case to further characterize the merits of TEB.

Emergent Endovascular Recanalization for Cervical Internal Carotid Artery Occlusion in Patients Presenting With Acute Stroke

BACKGROUND:Acute proximal (cervical) internal carotid artery (ICA) occlusion may cause ischemia of an entire hemisphere or no ischemia at all, depending on the presence of intracranial collaterals. OBJECTIVE:To retrospectively analyze the clinical results for emergent endovascular carotid recanalization in patients with acute proximal (cervical) ICA occlusion and to assess predictors of recanalization and clinical, neurological, and functional outcome. METHODS:Emergent endovascular revascularization was attempted in 22 patients presenting with acute stroke secondary to complete cervical ICA occlusion. Patients with pseudo-occlusion were excluded. Recanalization was assessed with the Thrombolysis in Myocardial Ischemia (TIMI) system: grade 0 (no flow) to grade 3 (normal flow). RESULTS:The median age of the patients was 65 years; mean admission National Institutes of Health Stroke Scale (NIHSS) score was 14. Recanalization (TIMI grade 2/3) occurred in 17 patients (77.3%). Ten patients (45.5%) demonstrated significant clinical improvement during hospitalization (NIHSS improved ≥4 points). Fifty percent of patients had good outcomes (modified Rankin Scale ≤2) after a median follow-up of 3 months. Patient age <70 years and successful recanalization (TIMI grade 2/3) predicted a good outcome (P ≤ .01). Presence of atrial fibrillation, admission NIHSS score ≥20, and complete ICA occlusion at all levels (cervical, petrocavernous, and intracranial) were associated with poor outcomes (P ≤ .05). Patients with complete cervical ICA occlusion but partial distal preservation of the vessel were most likely to benefit from the intervention (recanalization in 88.2%; good outcome in 64.7%). CONCLUSION:Attempts at emergent endovascular carotid recanalization for acute stroke are encouraged, particularly in younger patients with partial distal preservation of the ICA.

Diagnostic accuracy and inter-rater reliability of 64-multislice 3D-CTA compared to intra-arterial DSA for intracranial aneurysms

Catheter-based intra-arterial digital subtraction angiography (IADSA) is widely trusted for diagnosing cerebral aneurysms. However, three-dimensional CT angiography (3D-CTA) is evolving. This study compares the diagnostic performance and inter-rater reliability of 64-slice 3D-CTA and IADSA. Nineteen patients with 26 suspected cerebral aneurysms (23 with confirmed aneurysms, three negative controls) underwent both IADSA and 3D-CTA. Two independent reviewers assessed both imaging modalities for the presence of an aneurysm and subsequently described aneurysmal location, size, shape, orientation, and number of emanating arteries. Inter-observer agreement was followed to control for observer bias. The sensitivity of 3D-CTA was 78% and 96%, the negative predictive value (NPV) was 38% and 75%, and the accuracy of 3D-CTA was 81% and 96%. Both reviewers found 100% specificity and 100% positive predictive value (PPV). There was a clear correlation between 3D-CTA and IADSA for describing cerebral aneurysms. The authors conclude that 3D-CTA has equivocal diagnostic advantage but is less reliable for ruling out aneurysm presence. Anatomy, however, is superior with 3D-CTA.

The balloon anchor technique: a novel technique for distal access through a giant aneurysm

A novel technique is reported that helps the operator in achieving reliable access to the distal parent vessel with a microcatheter for stent assisted aneurysm coiling. Distal parent vessel access was obtained by allowing the microwire to follow the local hemodynamics into a giant internal carotid artery aneurysm and around its dome. Various traditional methods were tried before attempting the balloon anchor. In this technique, an over-the-wire balloon was inflated in the distal vessel followed by gentle retraction of the balloon catheter and microwire allowed only a wire bridge across the aneurysm neck, thereby allowing the stent catheter to be brought up in a standard fashion. This technique may facilitate the use of new stent technologies for the treatment of aneurysms that would otherwise be untreatable with endovascular therapies.