UPDATES IN INTRACRANIAL INTERVENTION Jordan Taylor DO Metro Health Neurology 2015
NEW STUDIES FOR 2015 MR CLEAN ESCAPE EXTEND-IA REVASCAT SWIFT PRIME
RECOGNIZED LIMITATIONS IV Alteplase proven benefit up to 4.5 hours Less effective in proximal occlusions Internal carotid artery terminus occlusion reperfusion in only about 1/3 of patients Proximal occlusion patients who often have a high NIH tend to have poor outcomes Limited time frame Many contraindications
TRIALS FAILING TO SHOW BENEFIT IMS III SYNTHESIS EXPANSION TRIAL MR RESCUE
IMS III
SYNTHESIS EXPANSION TRIAL
MR RESCUE
WHAT WENT WRONG Variety of catheters used (Solitaire, Penumbra, Merci, Trevo) May limit learning curve Variable ability to recanulize (older devices-lower rates) Relatively long time to intra-arterial treatment 3.45 hrs vs 2.45 hrs TPA (median time) in Synthesis expansion trial +/- 5.5 hrs in MR RESCUE Variable pre- endovascular imaging to confirm proximal occlusion Wide range of NIH stoke scales at randomization Higher NIH trended toward more significant benefit Relatively low rates of reperfusion
MR CLEAN A Randomized Trial of Intraarterial Treatment for Acute Ischemic Stroke Conducted in the Netherlands Randomized to either intraarterial treatment plus usual care and usual care alone Confirmed proximal anterior circulation arterial occlusion on CTA, MRA, or DSA Distal internal carotid artery, Middle cerebral artery (M1 or M2) Anterior cerebral artery (A1 or A2) Treatment needed to be initiated within 6 hours of stroke symptom onset Goal of lower modified Rankin score in endovascular group Third generation devices only
OUTCOMES
OUTCOMES Absence of residual occlusion Endovascular: 75.4%, control: 32.9% Infarct volume (median) Endovascular: 49 ml, control: 79 ml Modified Rankin scale at 90 days (median) Endovascular: 3, control: 4
LIMITATIONS Low relative proportion of patients in the control group ended with a modified Rankin of 0-2. May indicate a collection of patients with a poor prognosis from the beginning
ESCAPE Randomized Assessment of Rapid Endovascular Treatment of Ischemic Stroke Intended to identify and treat patients with a large vessel infarct with a small infarct core and moderate to good collateral circulation Used CT (ASPECTS), CTA (multiphase) Included occlusion of MCA and intermediate branches, with or without occlusion of ICA Identify candidates within 4.5 hours of onset ASPECTS of 6-10 Filling of 50% or more of MCA circulation on CTA
ESCAPE Retrievable stent devices preferred but available devices allowed All patients treated with IV t-pa within 4.5 hours Goal of CT to groin puncture of 60 min and CT to repurfusion of 90 min or less
OUTCOMES
OUTCOMES Study was halted early due to efficacy Proportion of patients with a modified Rankin at 90 days of 0-2 Endovascular: 53%, control 29.3% Modified Rankin scale at 90 days (median) Endovascular: 2, control: 4 Mortality at 90 days: Endovascular: 10.4%, control 19% Major success in achieving shorter interval (onset, CT to repurfusion) compared to earlier studies Imaging may be helpful in selecting candidates
LIMITATIONS Only 1.44 (average) participants per center per month were enrolled Device-related or procedural complications were observed in 18 patients Fairly narrow treatment group selected
EXTEND-IA Endovascular Therapy for Ischemic Stroke with Perfusion-Imaging Selection Test whether using advance imaging selection, recently developed devices, and earlier intervention improves outcomes Use of CT perfusion imaging to determine penumbra (salvageable tissue with low ischemic core volume) Occlusion in the internal carotid or middle cerebral artery Use of Solitaire FR stent retriever device Primary goal of reperfusion rather than clinical outcomes
EXTEND-IA
OUTCOMES
OUTCOMES Terminated early due to efficacy Patients with acute ischemic stroke from major vessel occlusion and salvageable tissue on CT perfusion imaging showed faster and more complete reperfusion with early mechanical thrombectomy after alteplase Substantial benefit in early neurologic outcomes and functional outcome at 3 months Managed statistically significant benefit despite small sample size
LIMITATIONS Small sample size Unable to perform subgroup analysis Patients with large ischemic core volume who may have benefited were excluded Early termination may overestimate effect
REVASCAT Thrombectomy within 8 hours after Symptom Onset in Ischemic Stroke Assess the safety and efficacy of thrombectomy for the treatment of stroke Used a population-based stroke repurfusion registry Confirmed proximal anterior circulation occlusion (MCA M1 w or w/o ICA) Absence of large ischemic core on CT (ASPECTS) or MRI Used Solitaire FR device Used ongoing quality improvement to reduce time to perfusion
REVASCAT Control: IV Alteplase within 4.5 hours or NO Alteplase in patients who had a contraindication Endovascular group then went on to have reperfusion with mechanical thrombectomy Only patients with residual occlusion 30 min after Alteplase were included As trial continued inclusion ASPECTS was increased (excluding more patients with a higher stroke burden)
OUTCOMES
OUTCOMES
OUTCOMES Stopped early due to emerging results from other endovascular studies Results consistent with the other studies confirming benefit of stent retriever devices
SWIFT PRIME Stent-Retriever Thrombectomy after Intravenous t-pa vs. t-pa Alone in Stroke Establish efficacy and safety of rapid neurovascular thrombectomy with a stent retriever and IV t-pa in acute ischemic stroke Solitaire FR or Solitaire 2 device alone without any cervical stenting Confirmed occlusion of intracranial internal carotid artery, MCA M1 segment or both Absence of large ischemic core (pnenumbra measured with RAPID (image postprocessing system)) Required history of experience with 40 or more mechanical thrombectomies Target of imaging to groin puncture within 70 minutes
OUTCOMES
OUTCOMES
LIMITATIONS Very narrow treatment group selected Continuous quality improvement measures where implemented through out the study and would have to be reproduced to show the same results All study sites were tertiary care centers and results may not generalize to other institutions
WHAT HAVE WE LEARNED? Patients with acute ischemic stroke and confirmed occlusion of either the ICA or proximal MCA benefit from rapid assessment and treatment with IV t- PA combined with new generation stent retrieval devices. The experience of the operator likely improves outcomes Patients with high initial NIH but low infarct core volume benefit the most.
LIMITATIONS GOING INTO THE FUTURE Low numbers of appropriate patients. (may be as low as 1-2 per month even in large centers) All studies had fairly restrictive inclusion criteria Many ischemic strokes will either involve other distributions (lacunar, etc) or have no residual occlusion in a large vessel at presentation Rapid assessment and treatment produces the most robust results so current policies and procedures will likely need to be modified to meet match the benefit. About 1/3 of patients in these studies will reperfuse with IV t-pa alone and may or may not need further treatment