Maxim Mokin

ADAPT FAST study: a direct aspiration first pass technique for acute stroke thrombectomy.

Background The development of new revascularization devices has improved recanalization rates and time, but not clinical outcomes. We report a prospectively collected clinical experience with a new technique utilizing a direct aspiration first pass technique with large bore aspiration catheter as the primary method for vessel recanalization. Methods 98 prospectively identified acute ischemic stroke patients with 100 occluded large cerebral vessels at six institutions were included in the study. The ADAPT technique was utilized in all patients. Procedural and clinical data were captured for analysis. Results The aspiration component of the ADAPT technique alone was successful in achieving Thrombolysis in Cerebral Infarction (TICI) 2b or 3 revascularization in 78% of cases. The additional use of stent retrievers improved the TICI 2b/3 revascularization rate to 95%. The average time from groin puncture to at least TICI 2b recanalization was 37 min. A 5MAX demonstrated similar success to a 5MAX ACE in achieving TICI 2b/3 revascularization alone (75% vs 82%, p=0.43). Patients presented with an admitting median National Institutes of Health Stroke Scale (NIHSS) score of 17.0 (12.0–21.0) and improved to a median NIHSS score at discharge of 7.3 (1.0–11.0). Ninety day functional outcomes were 40% (modified Rankin Scale (mRS) 0–2) and 20% (mRS 6). There were two procedural complications and no symptomatic intracerebral hemorrhages. Discussion The ADAPT technique is a fast, safe, simple, and effective method that has facilitated our approach to acute ischemic stroke thrombectomy by utilizing the latest generation of large bore aspiration catheters to achieve previously unparalleled angiographic outcomes.

Initial clinical experience with the ADAPT technique: A direct aspiration first pass technique for stroke thrombectomy

Background The development of new revascularization devices has improved recanalization rates and time but not clinical outcomes. We report our initial results with a new technique utilizing a direct aspiration first pass technique with a large bore aspiration catheter as the primary method for vessel recanalization. Methods A retrospective evaluation of a prospectively captured database of 37 patients at six institutions was performed on patients where the ADAPT technique was utilized. The data represent the initial experience with this technique. Results The ADAPT technique alone was successful in 28 of 37 (75%) cases although six cases had large downstream emboli that required additional aspiration. Nine cases required the additional use of a stent retriever and one case required the addition of a Penumbra aspiration separator to achieve recanalization. The average time from groin puncture to at least Thrombolysis in Cerebral Ischemia (TICI) 2b recanalization was 28.1 min, and all cases were successfully revascularized. TICI 3 recanalization was achieved 65% of the time. On average, patients presented with an admitting National Institutes of Health Stroke Scale (NIHSS) score of 16.3 and improved to an NIHSS score of 4.2 by the time of hospital discharge. There was one procedural complication. Discussion This initial experience highlights the fact that the importance of the technique with which new stroke thrombectomy devices are used may be as crucial as the device itself. The ADAPT technique is a simple and effective approach to acute ischemic stroke thrombectomy. Utilizing the latest generation of large bore aspiration catheters in this fashion has allowed us to achieve excellent clinical and angiographic outcomes.

Impact of onset-to-reperfusion time on stroke mortality: a collaborative pooled analysis.

Background— Onset-to-reperfusion time has been reported to be associated with clinical prognosis. However, its impact on mortality remained to be assessed. Using a collaborative pooled analysis, we examined whether early mortality after successful endovascular treatment is time dependent. Methods and Results— In a collaborative pooled analysis of 7 endovascular databases, we assessed the impact of onset-to-reperfusion time in large-artery occlusion (internal carotid artery or middle cerebral artery) on outcomes. Successful reperfusion was defined as complete or partial restoration of blood flow within 8 hours from symptom onset. Primary outcome was 90-day all-cause mortality. Secondary outcomes included 90-day favorable outcome (modified Rankin Scale score, 0–2), 90-day excellent outcome (modified Rankin Scale score, 0–1), and occurrence of any intracerebral hemorrhage within 24 to 36 hours after treatment. A total of 480 cases with successful reperfusion (median time, 285 minutes) contributed to the present pooled analysis (120 with internal carotid artery occlusion and 360 with isolated middle cerebral artery occlusion). Increasing onset-to-reperfusion time was associated with an increased rate of mortality and intracerebral hemorrhage and with a decreased rate of favorable and excellent outcomes, without heterogeneity across studies. The adjusted odds ratio for each 30-minute time increase was 1.21 (95% confidence interval, 1.09–1.34; P<0.001) for mortality, 0.79 (95% confidence interval, 0.72–0.87) for favorable outcome, 0.78 (95% confidence interval, 0.71–0.86) for excellent outcome, and 1.21 (95% confidence interval, 1.10–1.33) for intracerebral hemorrhage. Conclusion— Onset-to-reperfusion time affects mortality and favorable outcome and should be considered the main goal in acute stroke patient management.

Intravenous Thrombolysis and Endovascular Therapy for Acute Ischemic Stroke With Internal Carotid Artery Occlusion: A Systematic Review of Clinical Outcomes

Background and Purpose— Strokes secondary to acute internal carotid artery (ICA) occlusion are associated with extremely poor prognosis. The best treatment approach to acute stroke in this setting is unknown. We sought to determine clinical outcomes in patients with acute ischemic stroke attributable to ICA occlusion treated with intravenous (IV) systemic thrombolysis or intra-arterial endovascular therapy. Methods— Using the PubMed database, we searched for studies that included patients with acute ischemic stroke attributable to ICA occlusion who received treatment with IV thrombolysis or intra-arterial endovascular interventions. Studies providing data on functional outcomes beyond 30 days and mortality and symptomatic intracerebral hemorrhage (sICH) rates were included in our analysis. We compared the proportions of patients with favorable functional outcomes, sICH, and mortality rates in the 2 treatment groups by calculating &khgr;2 and confidence intervals for odds ratios. Results— We identified 28 studies with 385 patients in the IV thrombolysis group and 584 in the endovascular group. Rates of favorable outcomes and sICH were significantly higher in the endovascular group than the IV thrombolysis-only group (33.6% vs 24.9%, P=0.004 and 11.1% vs 4.9%, P=0.001, respectively). No significant difference in mortality rate was found between the groups (27.3% in the IV thrombolysis group vs 32.0% in the endovascular group; P=0.12). Conclusions— According to our systematic review, endovascular treatment of acute ICA occlusion results in improved clinical outcomes. A higher rate of sICH after endovascular treatment does not result in increased overall mortality rate.

Distal aspiration with retrievable stent assisted thrombectomy for the treatment of acute ischemic stroke

Objective Flexible large lumen aspiration catheters and stent retrievers have recently become available in the USA for the revascularization of large vessel occlusions presenting within the context of acute ischemic stroke (AIS). We describe a multicenter experience using a combined aspiration and stent retrieval technique for thrombectomy. Design A retrospective analysis to identify patients receiving combined manual aspiration and stent retrieval for treatment of AIS between August 2012 and April 2013 at six high volume stroke centers was conducted. Outcome variables, including recanalization rate, post-treatment National Institutes of Health Stroke Scale (NIHSS) score, symptomatic intracranial hemorrhage, discharge 90 day modified Rankin Scale (mRS) score, and mortality were evaluated. Results 105 patients were found that met the inclusion criteria for this retrospective study. Successful recanalization (Thrombolysis in Cerebral Infarction score 2B) was achieved in 92 (88%) of these patients. 44% of patients had favorable (mRS score 0–2) outcomes at 90 days. There were five (4.8%) symptomatic intracerebral hemorrhages and three procedure related deaths (2.9%). Conclusions Mechanical thrombectomy utilizing combined manual aspiration with a stent retriever is an effective and safe strategy for endovascular recanalization of large vessel occlusions presenting within the context of AIS.

A Multicenter Study of Stent-Assisted Coiling of Cerebral Aneurysms With a Y Configuration

BACKGROUND Stent-assisted coiling with 2 stents in a Y configuration is a technique for coiling complex wide-neck bifurcation aneurysms. OBJECTIVE We sought to provide long-term clinical and angiographic outcomes with Y-stent coiling, which are not currently established. METHODS Seven centers provided deidentified, retrospective data on all consecutive patients who underwent stent-assisted coiling for an intracranial aneurysm with a Y-stent configuration. RESULTS Forty-five patients underwent treatment by Y-stent coiling. Their mean age was 57.9 years. Most aneurysms were basilar apex (87%), and 89% of aneurysms were unruptured. Mean size was 9.9 mm. Most aneurysms were treated with 1 open-cell and 1 closed-cell stent (51%), with 29% treated with open-open stents and 16% treated with 2 closed-cell stents. Initial aneurysm occlusion was excellent (84% in Raymond grade I or II). Procedural complications occurred in 11% of patients. Mean clinical follow-up was 7.8 months, and 93% of patients had a modified Rankin Scale score of 0 to 2 at last follow-up. Mean angiographic follow-up was 9.8 months, and 92% of patients had Raymond grade I or II occlusion on follow-up imaging. Of those patients with initial Raymond grade III occlusion and follow-up imaging, all but 1 patient progressed to a better occlusion grade (83%; P < .05). Three aneurysms required retreatment because of recanalization (10%). There was no difference in initial or follow-up angiographic occlusion, clinical outcomes, incidence of aneurysm retreatment, or in-stent stenosis among open-open, open-closed, or closed-closed stent groups. CONCLUSION In a large multicenter series of Y-stent coiling for bifurcation aneurysms, there were low complication rates and excellent clinical and angiographic outcomes.

Solitaire flow restoration thrombectomy for acute ischemic stroke: Retrospective multicenter analysis of early postmarket experience after FDA approval

BACKGROUND The promising results of the Solitaire Flow Restoration (FR) With the Intention for Thrombectomy (SWIFT) trial recently led to Food and Drug Administration (FDA) approval of the Solitaire FR stent retriever device for recanalization of cerebral vessels in patients with acute ischemic stroke. OBJECTIVE To report the early postmarket experience with this device since its FDA approval in the United States, which has not been previously described. METHODS We conducted a retrospective analysis of consecutive acute ischemic strokes cases treated between March 2012 and July 2012 at 10 United States centers where the Solitaire FR was used as a single device or in conjunction with other intraarterial endovascular approaches. RESULTS A total of 101 patients were identified (mean age, 64.7 years; mean admission National Institutes of Health Stroke Scale [NIHSS] score, 17.6). Intravenous thrombolysis was administered in 39% of cases; other endovascular techniques were utilized in conjunction with the Solitaire FR in 52%. Successful recanalization (Thrombolysis in Myocardial Infarction 2/3) was achieved in 88%. The rate of symptomatic intracranial hemorrhage within the first 24 hours was 15%. In-hospital mortality was 26%. At 30 days, 38% of patients had favorable functional outcome (modified Rankin scale score ≤2). Severity of NIHSS score on admission was a strong predictor of poor outcome. CONCLUSION Our study shows that a variety of other endovascular approaches are used in conjunction with Solitaire FR in actual practice in the United States. Early postmarket results suggest that Solitaire FR is an effective tool for endovascular treatment of acute ischemic stroke.

Thrombus density predicts successful recanalization with Solitaire stent retriever thrombectomy in acute ischemic stroke

Background Thrombus characteristics, including Hounsfield unit (HU) value to measure density and thrombus volume and length, can predict successful recanalization following IV thrombolysis with recombinant tissue plasminogen activator. Conflicting and limited data exist regarding the value of assessing thrombus properties in acute stroke cases treated with endovascular IA approaches. Methods We retrospectively reviewed cases of anterior circulation acute ischemic stroke in which a Solitaire stent retriever (ev3-Covidien) was the primary treatment device. We measured the following thrombus characteristics: absolute and corrected HU values; thrombus length and volume; clot burden score; and vessel bifurcation involvement. Fishers exact test and the t test were used to study the association between these clot characteristics and successful recanalization (Thrombolysis in Cerebral Infarction (TICI) score 2b–3). Results We identified 41 patients with anterior circulation stroke treated with the Solitaire stent retriever as the primary treatment device. Successful recanalization (TICI score 2b–3) was achieved in 59% of cases. Higher absolute and corrected HU values were strongly predictive of successful recanalization (49.9±7.6 vs 43.8±6.6, p=0.01 for absolute HU values and 1.2±0.2 vs 1.0±0.1, p=0.03 for HU ratio in TICI 2b–3 and TICI 0–2a groups, respectively). There was no significant difference between recanalization and non-recanalization groups in the other thrombus characteristics studied. Conclusions In acute stroke treated with Solitaire stent retriever thrombectomy, higher thrombus HU values are predictive of successful recanalization. Such information can be used in decision making when estimating recanalization success rate with different endovascular treatment approaches.

Use of coils in conjunction with the pipeline embolization device for treatment of intracranial aneurysms.

BACKGROUND Coiling in conjunction with Pipeline embolization device (PED) placement could provide immediate dome protection and an intraaneurysmal scaffold to prevent device prolapse for intracranial aneurysms with high rupture risk and complex anatomy. OBJECTIVE To report results after treatment of aneurysms with PED with coils (PED+coils group) or without (PED-only group) at a single-institution. METHODS In this case-controlled study, records of patients who underwent PED treatment between 2011 and 2013 were retrospectively reviewed. RESULTS Twenty-nine patients were treated with PED+coils and 75 with PED-only. No statistically significant between-group differences were found in terms of age, sex, aneurysm location, medical comorbidities, and length of follow-up. Aneurysms treated by PED+coils were larger (16.3 mm vs 12.4 mm, P=.02) and more likely to be ruptured (20.7% vs 1.3%, P=.001) or dissecting (34.5% vs 9.3%, P=.002). PED deployment was successful in all cases. At the latest follow-up (mean, 7.8 months), complete aneurysm occlusion was achieved in a higher proportion of the PED+coils group (93.1% vs 74.7%, P=.03). Device foreshortening/migration occurred in 4 patients in the PED-only group and none in the PED+coils group. Fewer patients required retreatment in the PED+coils group (3.4% vs 16.0%, P=.71). Rates of neurological complications (10.3% PED+coils vs 8.0% PED-only, P=.7) and favorable outcome (modified Rankin Scale score=0-2; 93.1% PED+coils vs 94.7% PED-only, P=.6) were similar. CONCLUSION PED+coils may be a safe and effective treatment for aneurysms with high risk of rupture (or rerupture) and complex anatomy. Coiling in conjunction with PED placement provided a higher aneurysm occlusion rate and reduced the need for retreatment.

Challenges and limitations of patient-specific vascular phantom fabrication using 3D Polyjet printing

Additive manufacturing (3D printing) technology offers a great opportunity towards development of patient-specific vascular anatomic models, for medical device testing and physiological condition evaluation. However, the development process is not yet well established and there are various limitations depending on the printing materials, the technology and the printer resolution. Patient-specific neuro-vascular anatomy was acquired from computed tomography angiography and rotational digital subtraction angiography (DSA). The volumes were imported into a Vitrea 3D workstation (Vital Images Inc.) and the vascular lumen of various vessels and pathologies were segmented using a “marching cubes” algorithm. The results were exported as Stereo Lithographic (STL) files and were further processed by smoothing, trimming, and wall extrusion (to add a custom wall to the model). The models were printed using a Polyjet printer, Eden 260V (Objet-Stratasys). To verify the phantom geometry accuracy, the phantom was reimaged using rotational DSA, and the new data was compared with the initial patient data. The most challenging part of the phantom manufacturing was removal of support material. This aspect could be a serious hurdle in building very tortuous phantoms or small vessels. The accuracy of the printed models was very good: distance analysis showed average differences of 120 μm between the patient and the phantom reconstructed volume dimensions. Most errors were due to residual support material left in the lumen of the phantom. Despite the post-printing challenges experienced during the support cleaning, this technology could be a tremendous benefit to medical research such as in device development and testing.