***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: See related article , p 2509  Intra-arterial therapy ( IAT ) for acute ischemic stroke ( AIS ) has dramatically evolved during the past decade to include aspiration and stent-retriever devices . Recent r and omized controlled trials have demonstrated the superior revascularization efficacy of stent-retrievers compared with the first-generation Merci device.1,2 Additionally , the Diffusion and Perfusion Imaging Evaluation for Underst and ing Stroke Evolution ( DEFUSE ) 2 , the Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy ( MR RESCUE ) , and the Interventional Management of Stroke ( IMS ) III trials have confirmed the importance of early revascularization for achieving better clinical outcome .3–5 Despite these data , the current heterogeneity in cerebral angiographic revascularization grading ( CARG ) poses a major obstacle to further advances in stroke therapy . To date , several CARG scales have been used to measure the success of IAT.6–14 Even when the same scale is used in different studies , it is applied using varying operational criteria , which further confounds the interpretation of this key metric.10 The lack of a uniform grading approach limits comparison of revascularization rates across clinical trials and hinders the translation of promising , early phase angiographic results into proven , clinical ly effective treatments.6–14 For these reasons , it is critical that CARG scales be st and ardized and end points for successful revascularization be refined.6 This will lead to a greater underst and ing of the aspects of revascularization that are strongly predictive of clinical response . The optimal grading scale must demonstrate ( 1 ) a strong correlation with clinical outcome , ( 2 ) simplicity and feasibility of scale interpretation while ensuring characterization of relevant angiographic findings , and ( 3 ) high inter-rater reproducibility . To address these issues , a multidisciplinary panel of neurointerventionalists , neuroradiologists , and stroke neurologists with extensive experience in neuroimaging and IAT , convened at the “ Consensus Meeting on Revascularization Grading Following Endovascular Therapy ” with the goal Background Limited efficacy of IV recombinant tissue plasminogen activator ( rt-PA ) for large vessel occlusions ( LVO ) raises doubts about its utility prior to endovascular therapy . Purpose To compare outcomes and hospital costs for anterior circulation LVOs ( middle cerebral artery , internal carotid artery terminus ( ICA-T ) ) treated with either primary endovascular therapy alone ( EV-Only ) or bridging therapy ( IV+EV ) ) . Methods A single-center retrospective analysis was performed . Clinical and demographic data were collected prospect ively and relevant cost data were obtained for each patient in the study . Results 90 consecutive patients were divided into EV-Only ( n=52 ) and IV+EV ( n=38 ) groups . There was no difference in demographics , stroke severity , or clot distribution . The mean ( SD ) time to presentation was 5:19 ( 4:30 ) hours in the EV-Only group and 1:46 ( 0:52 ) hours in the IV+EV group ( p<0.0001 ) . Recanalization : EV-Only 35 ( 67 % ) versus IV+EV 31 ( 81.6 % ) ( p=0.12 ) . Favorable outcome : EV-Only 26 ( 50 % ) versus IV+EV 22 ( 58 % ) ( p=0.45 ) . For patients presenting within 4.5 hours ( n=64 ) : Recanalization : EV-Only 21/26 ( 81 % ) versus IV+EV 31/38 ( 81.6 % ) ( p=0.93 ) . Favorable outcome : EV-Only 14/26 ( 54 % ) versus IV+EV 22/38 ( 58 % ) ( p=0.75 ) . There was no significant difference in rates of hemorrhage , mortality , home discharge , or length of stay . A stent retriever was used in 67 cases ( 74.4 % ) , with similar recanalization , outcomes , and number of passes in the EV-Only and IV+EV groups . The mean ( SD ) total hospital cost was $ 33 810 ( 13 505 ) for the EV-Only group and $ 40 743 ( 17 177 ) for the IV+EV group ( p=0.02 ) . The direct cost was $ 23 034 ( 8786 ) for the EV-Only group and $ 28 711 ( 11 406 ) for the IV+EV group ( p=0.007 ) . These significantly higher costs persisted for the subgroup presenting in < 4.5 hours and the stent retriever subgroup . IV rt-PA administration independently predicted higher hospital costs . Conclusions IV rt-PA did not improve recanalization , thrombectomy efficacy , functional outcomes , or length of stay . Combined therapy was associated with significantly higher total and direct hospital costs than endovascular therapy alone Importance Intravenous thrombolysis ( IVT ) followed by mechanical thrombectomy ( MT ) is recommended to treat acute ischemic stroke ( AIS ) with a large vessel occlusion ( LVO ) . Most hospitals do not have on-site MT facilities , and most patients need to be transferred secondarily after IVT ( drip and ship ) , which may have an effect on the neurologic outcome . Objective To compare the functional independence at 3 months between patients treated under the drip- and -ship paradigm and those treated on site ( mothership ) . Design , Setting , and Participants This study used a prospect ively gathered registry of patients with AIS to select patients admitted through the Saint-Antoine and Tenon ( drip and ship ) or the Fondation Rothschild ( mothership ) hospitals from January 1 , 2013 , through April 30 , 2016 . The study included patients older than 18 years treated with bridging therapy for AIS with LVO of the anterior circulation . Among the 159 patients who received MT at the mothership , 100 had been transferred after IVT  from the drip- and -ship hospitals and 59 had received IVT on site . Main Outcomes and Measures The main outcome was 3-month functional independence ( modified Rankin scale score ⩽2 ) . Both groups were compared using a multivariate linear model , including variables that were significantly different in the 2 groups . Results During the study period , 497 patients were hospitalized at the drip- and -ship and mothership hospitals for an AIS eligible to reperfusion therapy ; 11 patients had a basilar artery occlusion and were excluded , leaving 100 patients in the drip- and -ship group ( mean age , 73 years ; age range , 60 - 81 years ; 57 men [ 57.0 % ] ) and 59 in the mothership group ( mean age , 70 years ; age range , 58 - 82 years ; 29 men [ 49.2 % ] ) . The proportion of patients with a favorable neurologic outcome at 3 months was similar in both groups ( drip and ship , 61 [ 61.0 % ] ; mothership , 30 [ 50.8 % ] ; P = .26 ) , even after adjusting the analysis for the baseline National Institutes of Health Stroke Scale score , diffusion-weighted imaging Alberta Stroke Program Early Computed Tomography Score , and general anesthesia ( P = .82 ) . Patients had less severe conditions in the drip- and -ship group ( median baseline National Institutes of Health Stroke Scale score , 15 vs 17 [ P = .03 ] ; median diffusion-weighted imaging Alberta Stroke Program Early Computed Tomography Score , 7.5 vs 7 [ P = .05 ] ) . Process times were longer in the drip- and -ship group ( onset-to-needle time , 150 vs 135 minutes ; onset-to-puncture time , 248 vs 189 minutes ; and onset-to-recanalization time , 297 vs 240 minutes ; P < .001 ) . Both groups were similar in terms of substantial recanalization ( Thrombolysis in Cerebral Ischemia scores 2B to 3 ; drip and ship , 84 [ 84.0 % ] ; mothership , 47 [ 79.7 % ] ; P = .49 ) and symptomatic hemorrhagic transformation ( drip and ship , 2 [ 2.0 % ] ; mothership , 2 [ 3.4 % ] ; P = .63 ) . Conclusions and Relevance This study found that patients treated under the drip- and -ship paradigm also benefit from bridging therapy , with no statistically significant difference compared with those treated directly in a comprehensive stroke center Background and purpose The present study was conducted with the objective of evaluating the safety of primary mechanical thrombectomy ( MT )  in patients with large vessel occlusion ( LVO ) stroke and comorbidities that preclude treatment with IV thrombolysis ( IVT )  , compared with patients who received st and ard IVT treatment followed by MT .  Secondary objectives were to analyse the recanalization rate and outcomes . Methods A prospect i ve observational multicenter study ( FUN-TPA ) that recruited patients treated within 4.5 hours of symptom onset was performed . Treatments were IVT followed by MT if occlusion persisted , or primary MT when IVT was contraindicated . Outcome measures were procedural complications , symptomatic intracranial hemorrhage ( SICH ) , recanalization rate , National Institutes of Health Stroke Scale ( NIHSS ) score at 7 days , modified Rankin Scale ( mRS ) score and mortality at 90 days . Results Of 131 patients , 21 ( 16 % ) had medical contraindications for IVT and were treated primarily with MT  whereas 110 ( 84 % ) underwent IVT , followed by MT in 53 cases ( 40 % ) . The recanalization rate and procedural complications were similar in the two groups . There were no SICHs after primary MT vs 3 ( 6 % ) after IVT+MT . Nine patients ( 43 % ) in the primary MT group achieved independence ( mRS 0–2 ) compared with 36 ( 68 % ) in the IVT+MT group ( p=0.046 ) . Mortality rates in the two groups were 14 % ( n=3 ) vs 4 % ( n=2 ) ( p=0.13 ) . Adjusted ORs for independence in patients receiving st and ard IVT+MT vs MT in patients with medical contraindications for IVT were 2.8 ( 95 % CI 0.99 to 7.98 ) and 0.24 ( 95 % CI 0.04 to 1.52 ) for mortality . Conclusions MT is safe in patients with potential comorbidity-derived risks that preclude IVT . MT should be offered , aim ing for prompt recanalization , to patients with LVO stroke unsuitable for IVT . Trial registration number NCT02164357 ; Results Background and Purpose — In patients with ischemic stroke , r and omized trials showed a better functional outcome after endovascular therapy with new-generation thrombectomy devices compared with medical treatment , including intravenous thrombolysis . However , effects on mortality and the generalizability of results to routine clinical practice are uncertain . Methods — In a prospect i ve observational register-based study patients with ischemic stroke treated either with thrombectomy , intravenous thrombolysis , or their combination were included . Primary outcome was the modified Rankin scale score ( 0 [ no symptoms ] to 6 [ death ] ) at 3 months . Ordinal logistic regression was used to estimate the common odds ratio as treatment effects ( shift analysis ) . Propensity score matching was applied to compare patients treated either with intravenous thrombolysis alone or with intravenous thrombolysis plus thrombectomy . Results — Among 2650 recruited patients , 1543 received intravenous thrombolysis , 504 underwent thrombectomy , and 603 received intravenous thrombolysis in combination with thrombectomy . Later time-to-treatment was associated with worse outcomes among patients treated with thrombectomy plus thrombolysis . In 241 pairs of propensity score – matched patients with a proximal intracranial occlusion , thrombectomy plus thrombolysis was associated with improved functional outcome ( common odds ratio , 1.84 ; 95 % confidence interval , 1.32–2.57 ) , and reduced mortality ( 15 % versus 33 % ; P<0.0001 ) compared with intravenous thrombolysis alone . Results were similar in various sensitivity analyses accounting for missing outcome data and different analytic methods . Conclusions — Results from this large prospect i ve registry show that also in routine clinical care thrombectomy plus thrombolysis compared with thrombolysis alone improved functional outcome and reduced mortality in patients with ischemic stroke . Earlier treatment was associated with better outcomes Background and Purpose — R and omized controlled trials have shown that mechanical thrombectomy ( MT ) plus best medical treatment improves outcome in stroke patients with large-vessel occlusion in the anterior circulation . Whether direct MT is equally effective as bridging thrombolysis ( intravenous thrombolysis plus MT ) in intravenous thrombolysis eligible patients remains unclear . Methods — We compared clinical and radiological outcomes at 3 months in 249 bridging patients with 111 patients receiving direct MT for large-vessel occlusion anterior circulation stroke from 2 prospect i ve registries ( study period Essen : June 2012 to August 2013 , Bern February 2009 to August 2014 ) . We matched all patients from the  direct 
    Output:
    
Pre-IVT provides extra benefits to MT on clinical and imaging outcomes without increasing symptomatic intracerebral hemorrhage in acute ischemic stroke of large vessel occlusion