Complications of endovascular treatment for acute stroke in the SWIFT trial with solitaire and Merci devices.

BACKGROUND AND PURPOSE: Treatment of patients with ischemic stroke after endovascular treatment requires in-depth knowledge of complications. The goal of this study was to make endovascular treatment for acute ischemic stroke safer through an in-depth review of the major periprocedural complications observed in the Solitaire FR With Intention for Thrombectomy (SWIFT) trial. MATERIALS AND METHODS: The SWIFT data base was searched for major peri-procedural complications defined as symptomatic intracranial hemorrhage within 36 hours, SAH, air emboli, vessel dissection, major groin complications, and emboli to new vascular territories. RESULTS: Major peri-procedural complications occurred in 18 of 144 patients (12.5%) as follows: symptomatic intracranial hemorrhage, 4.9%; air emboli, 1.4%; vessel dissection, 4.2%; major groin complications, 2.8%; and emboli to new vascular territories, 0.7%. Rates of symptomatic intracranial bleeding by subtype were PH1, 0.7%; PH2, 0.7% (PH1 indicates hematoma within ischemic field with some mild space-occupying effect but involving ≤ 30% of the infarcted area; PH2, hematoma within ischemic field with space-occupying effect involving >30% of the infarcted area); intracranial hemorrhage remote from ischemic zone, 0%; intraventricular hemorrhage, 0.7%; and SAH, 3.5%. We did not observe any statistically significant associations of peri-procedural complications with age; type of treatment center; duration of stroke symptoms; NIHSS score, IV thrombolytics, atrial fibrillation, site of vessel occlusion; rescue therapy administered after endovascular treatment; or device. Comparing the Merci with the Solitaire FR retrieval device, we observed symptomatic cerebral hemorrhage (10.9% versus 1.1%; P = .013); symptomatic SAH (7.3% versus 1.1%; P = .07), air emboli (1.8% versus 1.1%; P = 1.0), emboli to new vascular territories (1.8% versus 0%; P = .38), vessel dissection (1.8% versus 4.5%; P = .65), and major groin complications (3.6% versus 7.9%; P = .48). Angiographic vasospasm was common but without clinical sequelae. CONCLUSIONS: Understanding of procedural complications is important for treatment of patients with stroke after endovascular treatment. We observed fewer endovascular complications with the Solitaire FR device treatment compared with Merci device treatment, particularly symptomatic cerebral hemorrhage.

Endovascular mechanical thrombectomy for the treatment of acute ischemic stroke due to arterial dissection.

Arterial dissections account for 2% of strokes in all age groups, and up to 25% in patients aged 45 years or younger. The safety of endovascular intervention in this patient population is not well characterized. We identified all patients in the Merci registry - a prospective, multi-center post-market database enrolling patients treated with the Merci Retriever thrombectomy device - with arterial dissection as the most likely stroke etiology. Stroke presentation and procedural details were obtained prospectively; data regarding procedural complications, intracerebral hemorrhage (ICH), and the use of stenting of the dissected artery were obtained retrospectively. Of 980 patients in the registry, ten were identified with arterial dissection (8/10 ICA; 2/10 vertebrobasilar). The median age was 48 years with a baseline NIH stroke scale score of 16 and median time to treatment of 4.9 h. The procedure resulted in thrombolysis in cerebral ischemia (TICI) scores of 2a or better in eight out of ten and TICI 2b or better in six out of ten patients. Stenting of the dissection was performed in four of nine (44%). The single complication (1/9; 11%) - extension of a dissected carotid artery - was treated effectively with stenting. No symptomatic ICH or stroke in a previously unaffected territory occurred. A favorable functional outcome was observed in eight out of ten patients. Despite severe strokes on presentation, high rates of recanalization (8/10) and favorable functional outcomes (8/10) were observed. These results suggest that mechanical thrombectomy in patients with acute stroke resulting from arterial dissection is feasible, safe, and may be associated with favorable functional outcomes.

Higher degrees of recanalization after mechanical thrombectomy for acute stroke are associated with improved outcome and decreased mortality: pooled analysis of the MERCI and Multi MERCI trials.

BACKGROUND AND PURPOSE: Although the combined end point of partial and complete recanalization is a well-established predictor of good outcome following acute stroke intervention, few investigations have evaluated the effect of the degree of recanalization. We hypothesized that greater degrees of recanalization would be associated with a higher likelihood of favorable functional outcomes. MATERIALS AND METHODS: Data from MERCI and Multi MERCI-prospective single-arm trials of endovascular mechanical thrombectomy for acute stroke-were pooled. The TIMI score was used to define the degree of recanalization, and a favorable outcome was defined as an mRS score of 0-2 at 90 days. RESULTS: A total of 305 patients were included. Age, stroke severity, and site of arterial occlusion did not differ among groups stratified by the TIMI score. The unadjusted OR for a favorable outcome increased significantly as the TIMI score increased from 0 to 1 (OR, 5.9; 95% CI, 1.7-20.0; P = .007) and from 2 to 3 (OR. 2.3; 95% CI, 1.2-4.5; P = .01) and the likelihood of death decreased significantly as the TIMI score increased from 2 to 3 (OR, 2.2; 95% CI, 1.1-4.3; P = .05). In multivariate analysis, each increase in TIMI grade increased the odds of a good outcome 2.6-fold (95% CI, 1.9-3.4, P < .0001). CONCLUSIONS: Increases in the TIMI score were highly associated with improved outcomes. This finding not only provides additional evidence that restoration of blood flow improves clinical outcomes in ischemic stroke but also suggests that interventionalists should strive for complete revascularization when they provide endovascular treatment for acute ischemic stroke.

Drug eluting stents for symptomatic intracranial and vertebral artery stenosis.

The use of bare metal stents (BMS) to prevent recurrent stroke due to stenosis of the cerebral vasculature is associated with high rates of restenosis. Drug-eluting stents (DES) may decrease this risk. We evaluated the performance of DES in a cohort of patients treated at our institution.Consecutive patients treated with DES were identified by a case log and billing records; data regarding procedural details, clinical outcome and angiographic follow-up was obtained by retrospective chart review.Twenty-six patients (27 vessels; 14 vertebral origin (VO); 13 intracranial) were treated. Stenosis was reduced from mean 81% to 8% at the VO and 80% to 2% intracranially. No strokes occurred in the first 24 hours after stenting or at any time point in the VO group during a mean follow-up period of nine months. Among patients with intracranial stents, stroke with permanent disability occurred within 30 days in 1/12 (8%) and after 30 days in 1/11 (9%) with clinical follow-up (mean follow-up, 14 months). Follow-up catheter angiography was obtained in 14/14 (100%) in the VO group at mean eight months and in 8/11 surviving patients (73%) at a mean of ten months after stenting in the intracranial group. The restenosis rate was 21% at the VO (3/14) and 38% (3/8) for intracranial stents. Restenosis at the VO was less frequent than might have been expected from reports utilizing BMS, however, overall restenosis rates appeared higher than previously reported for patients with intracranial DES and comparable with restenosis rates for intracranial BMS.

Femoral artery complications associated with the Mynx closure device.

BACKGROUND AND PURPOSE: Devices to close a femoral arteriotomy are frequently used after catheterization for interventional radiology and cardiac procedures to decrease the time to hemostasis and ambulation and, potentially, to decrease local complications. The Mynx vascular closure device uses a sealant designed to occlude the access tract, resulting in hemostasis. MATERIALS AND METHODS: We retrospectively reviewed all cases in which the Mynx device was used and for which follow-up angiography was available. A total of 146 devices were deployed in 135 patients. A follow-up vascular study visualizing the femoral artery was performed in 26 patients (27 studies). RESULTS: There were 5 (5/27, 18%) cases of intravascular Mynx sealant on follow-up vascular imaging. Three pseudoaneurysms (3/27, 11%) were identified. CONCLUSIONS: In this small study, intravascular sealant and pseudoaneurysms were found frequently after femoral arterial closure with the Mynx vascular closure device.

Surface-mediated reactions. 9. Selective oxidation of primary and secondary amines to hydroxylamines.

OXONE over silica gel or, in some cases, alumina has been found to oxidize the primary and secondary amines 3 selectively to the corresponding hydroxylamines 4, in either the presence or absence of a solvent. Treatment of Boc-protected L-lysine (6) under the latter conditions afforded hydroxylamine 7 in excellent yield. The trialkylamine 1a and pyridine (1b), in which selectivity is not an issue, were readily oxidized to the corresponding oxides 2 by OXONE over silica gel or alumina, as well as by (CH(3))(3)COOH over silica gel. Solvent-free oxidation assisted by microwave irradiation was more forcing, while still affording the hydroxylamines 4 selectively, and is the synthetic method of choice. The mechanistic aspects of these reactions are discussed.

Single-chain lambda Cro repressors confirm high intrinsic dimer-DNA affinity.

The overall affinity of the bacteriophage lambda Cro repressor for its operator DNA site is limited by dimer dissociation at submicromolar concentrations. Since Cro dimer-operator complexes form at nanomolar concentrations of Cro subunits where free dimers are rare, these dimers must bind with compensating high affinities. Previous studies of the covalent dimer Cro V55C suggest little change in DNA binding affinity even though the dimeric species is quantitatively populated; this is an apparent contradiction to the expectation of high intrinsic dimer-DNA affinity. In contrast to the disulfide linkage at the center of the dimer interface in Cro V55C, polypeptide linkers that join the two subunits allow single-chain Cro repressors to bind operator DNA with picomolar affinities. A series of five single-chain Cro repressors have been expressed from fused tandem cro genes. Each contains a peptide linker of 8-16 hydrophilic residues that connects the C-terminus of one subunit to the N-terminus of the next. All bind to operator DNA with at least 100-fold higher affinity than Cro V55C. Proteins containing the longest and shortest linkers have been purified and characterized in detail. Both exhibit similar CD spectra to wild-type Cro and enhanced thermal stability. Sedimentation equilibrium experiments show that single-chain Cro repressors do not associate at concentrations up to 30 microM. The rate of dissociation of Cro-DNA complexes is almost unchanged by covalent linkage. Biophysical characterization of Cro variants such as these, where DNA binding is uncoupled from subunit assembly, is necessary for a quantitative understanding of the structural and energetic determinants of DNA recognition in this simple model system.

Preventing child abuse and neglect in Texas.

The rising prevalence of child abuse and neglect in Texas underscores the need to encourage innovative programs across the state. Primary prevention efforts catalyzed by the Children's Trust Fund of Texas demonstrate such projects. Specific evaluation techniques are also reviewed with some explanation of why some programs may be more effective than others.