1. Patient enrollment DIAS-4 vs. Endovascular Therapy
What does the cath lab offer?

2. MERCI® Retrieval System

3. Mechanical Thrombectomy: The MERCI Trial
151 pts with intracranial occlusions treated <8 hr from symptom onset (no control group)
Recanalization in 48%; SICH in 8%
Improved patient outcomes with recanalization
46% vs 10% without disability at 90 days
Smith WS et al. Stroke. 2005;36:1432

4. FDA Approval of MERCI Retriever: August 2004
Indications for Use:
“The Merci Retriever is intended to restore blood flow in the neurovasculature by removing thrombus in patients experiencing ischemic stroke. Patients who are ineligible for treatment with intravenous tissue plasminogen activator (IV t-PA) or who fail IV t-PA therapy are candidates for treatment."
Food and Drug Administration website. Available at Accessed Jan 24, 2008

5. Multi MERCI L5

6. Improved Recanalization
100 90 80
69.5 70
57.3
60.3 60
48.2 % 50
MERCI 40
Multi MERCI L5 30 20 10
Device
Final
Recanalization
Recanalization
Slide courtesy of WS Smith.

7. Mechanical Thrombectomy:
PENUMBRA®

8. Penumbra System: Registration Trial
125 patients
NIHSS 17.6
Recanalization (TIMI 2-3) 82%
SICH 11.2%
Nondisabled (mRS 0-2) outcome 90 d 25%
Death 90 d 33% 8

9. SOLITAIRE With the Intention For Thrombectomy (SWIFT) Study :9

10. Misperceptions in brain ischemia: technology, terminology, tissue and time
Mechanical Recanalization: Misperceptions about Terminology: regulatory
“The term "FDA approval" is never appropriate to describe a device that is legally marketed under a 510(k). The correct term is "cleared for marketing" or "cleared by FDA". Neurothrombectomy devices currently on the market in the US have been cleared via the 510(k) pathway.”
Natalie Getzoff, MD, Medical Officer Neurodiagnostic and Neurotherapeutic Devices Branch Division of Ophthalmic, Neurological, and ENT Devices Food and Drug Administration
True or False?
Two mechanical thrombectomy devices have been approved for use in stroke patients by the FDA

11. Mechanical Recanalization: Misperceptions
Misperceptions in brain ischemia: technology, terminology, tissue and time
Mechanical Recanalization: Misperceptions
Our job to figure out which patients benefit from these devices
How well are we doing?
Case series:
“My recanalization rate
is bigger than yours”

12. Misperceptions in brain ischemia: technology, terminology, tissue and time
Mechanical Recanalization: Misperceptions about Terminology: recanalization
confusing and misleading
Thomas Tomsick
Department of Radiology
University Hospital
Cincinnati, Ohio

13. Complete success Partial success No success
Misperceptions in brain ischemia: technology, terminology, tissue and time
Mechanical Recanalization: Misperceptions about Technology: recanalization
Complete success
Partial success
No success
recanalization
no recanalization

14. Endovascular Therapy: Clinical Trials
MR Rescue
IMS 3
DEFUSE 2

15. DEFUSE 2 Protocol MRI MRI MRI Intra-arterial therapy
baseline
MRI
post-procedure
(reperfusion)
MRI
day 5
(infarct volume)
Intra-arterial
therapy
Favorable clinical response:
NIHSS score of 0-1 at day 30 or improvement of NIHSS score by ≥ 8 points between baseline and day 30 15

16. 66 yo, MCA M1 occlusion Recanalization of ant temporal branch of MCA
Recanalization; 20% reperfusion = TIMI 2, TICI 2A
66 yo, MCA M1 occlusion 16

17. 74 yo, R MCA occlusion at 9 hrs (witnessed), NIHSS 1217

18. Early f/u DWI/PWI at 11 hrs; NIHSS 6 cath lab merci (10 hrs) and 3 mg IA tPA (10.5 hrs)18

19. Baseline DWI; NIH 12 5-day FLAIR; NIH 3 7 ccm 10 ccm19

20. 79 yo female, left hemiplegia
Angiogram pre and post Penumbra device (7 hrs)

21. CTP at 6 hrs (prior to cath lab)
DWI / PWI 10 hrs after cath lab
DWI / PWI 10 hrs after cath lab
DWI at Day 3

22. Patient enrollment DIAS-4 vs. Endovascular Therapy
Must avoid biased enrollment in DIAS (M1s cath lab, M2s DIAS; high NIH vs. low; investigator impression of prognosis)
Various non-biased strategies possible
Communication/consensus with IA team on a site-specific plan