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 post-

processing 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