Endovascular clot retrieval

Risks/adverse events

· Symptomatic ICH 3.6-9.3%

· Subarachnoid haemorrhage 0.6-4.9%

· Vessel Perforation 1.6%

· Arterial dissection 0.6-3.9%

· Emboli to new territories 1.0-8.6%

· Vasospasm

· Vascular access complications

o Dissection

o Pseudoaneurysm

o Retroperitoneal haematoma

o Infection

· Stent retriever detachment 2-3%

· Overall complication rate ~15%

Summary of Trials

HERMES paper – meta-analysis of all previous RCTs

• All trials looked at patients with occlusion of ICA or M1

• Only 94 M2 occlusion patients included in the trials – no indication that they do worse (but not statistically significant)

From practical neurology 2017:

MR CLEAN Study

• NEJM 2014

• 500pts in Netherlands (all stoke centres in the country participated)

Inclusion:

• All patients with proximal occlusion and NIHSS at least 2

• Included patients with contraindication to IV TPA

• Randomized to usual care vs usual care +IA therapy

• IA therapy could include IA TPA or mechanical removal

• Mechanical removal technique was at local discretion; ~80% was with stent-retriever

• Median NIHSS 17-18

Results:

• mRS 0-2 (functionally independent) at 90days

o 32.6% vs 19.1%

o ARR 13.5% (NNT – 7.4)

o OR 2.16

• 5.6% of intervention patient vs 0.4% of control patients had a stroke in another vascular territory within 90days

Discussion:

• Probably succeeded because unlike the previous 2 negative trials:

o It recruited all eligible patients in the country (unlike in USA where it was the ‘leftovers’)

o It required a proximal occlusion to be demonstrated

o ‘Modern’ stent retriever was used for the majority

• Many patient’s in intervention group also had ICA stenosis stented at the same time which may have contributed to increased recurrent stroke rate.

Prolonged time frame trials of mechanical thrombectomy

DAWN trial

• NEJM 2018

• USA based

• ~100 patients in each arm

• Inclusion:

o Occlussion of intracranial ICA or M1

o Time of onset 6-24 hours

o Premorbid MRS 0-1

o Group A

- Age >80

- NIHSS >10

- Core <21ml

o Group B

- Age <80

- NIHSS >10

- Core <31ml

o Group C

- Age <80

- NIHSS >20

- Core 31-51ml

• Software - RAPID

• Patient characteristics

o Av Age ~70

o NIHSS median 17

o Treated with TPA 5v13%

o Core median 7.6 v 8.9ml

o Onset time median ~12hours

• Outcomes

o Functional independence 90 days - 49 vs 13%

o Infarct core at 24 hours – 8 vs 22 ml

No major difference in subgroups

• Safety

o No difference in death rates

o ICH at 24 hours 6% vs 3%

o Procedural complications 7%

DEFUSE trial

• NEJM 2018

• USA based

• ~90 patients in each arm

• Software – RAPID

o Ischaemia = Tmax >6 sec

• Inclusion

o 6-16 hours after last seen well

o Occlusion of cervical or intracranial ICA or proximal MCA

o Core <70ml

o Ratio penumbra/core > 1.8

o Penumbra >15ml

• Patient characteristics

o Age median 70yrs

o NIHSS 16

o TPA ~10%

o Median core ~10ml

o Median penumbra 115ml

o Time – onset to randomisation - ~11hours

• Outcomes

o mRS at 90 days 3 vs 4

o Functional independence at 90 days 41% vs 15%

o Trend to reduced death 14% vs 26%

o ICH 9% vs 3%