Surgical Indirect Revascularization For Symptomatic Intracranial Arterial Stenosis

Intracranial arterial atherosclerosis is a significant medical problem, with elevated rates
of recurrent stroke despite medical therapy, with annual recurrence rates for ischemic stroke
reported in the SAMMPRIS Trial as high as 12.2% in the intensive medical therapy arm. The
incidence of recurrence stroke can be even higher in some high-risk groups, as high as 25% in
African-Americans and females. The ultimate goal of this project is to advance a promising
surgical treatment for symptomatic atherosclerotic intracranial stenosis -
encephaloduroarteriosynangiosis (EDAS). Compared with direct revascularization operations
(bypass), EDAS has the advantages of being less technically demanding, avoiding temporary
occlusion of cerebral vessels, and allowing gradual development of collateral circulation
where the brain demands it, deterring early hyperperfusion and hemorrhage. There has been no
systematic trial exploring the use of EDAS in cases of symptomatic, non-moyamoya intracranial
arterial stenosis. Based on preliminary positive results, the investigators propose the
long-term objective of demonstrating that EDAS improves the outcome in patients with
symptomatic intracranial stenosis compared with aggressive medical therapy. This will require
future phase III clinical trials. The present proposal has the purpose of testing in a phase
II futility-design trial the potential of EDAS for further development before proceeding with
the design of a definitive clinical trial of EDAS Revascularization in patients with
Symptomatic Intracranial Arterial Stenosis (ERSIAS). The present project will be 4-year
futility-design trial to determine if EDAS revascularization combined with aggressive medical
therapy warrants further evaluation in a subsequent pivotal trial as an alternative to
aggressive medical management alone for preventing the primary endpoint of stroke or death at
two years in patients with symptomatic intracranial arterial stenosis (Specific Aim 1).
During the investigation the investigators will systematically evaluate the time course of
collateralogenesis and perfusion improvement following EDAS by using quantitative and
semiquantitative perfusion MRI studies (Specific Aim 2). The new knowledge generated by this
study on understanding the role of collateral circulation in stroke pathophysiology, patient
selection, and use of non-invasive imaging will be useful not only for EDAS evaluation but
potentially next generation stents and future novel medical therapies, such as use of
angiogenic growth factors and/or endothelial stem cells.

Inclusion Criteria:

1. TIA or non-severe stroke within 30 days of enrollment attributed to 70% to 99%
stenosis* of a major intracranial artery (carotid artery or MCA)

*May be diagnosed by TCD, MRA, or CTA to qualify, but must be confirmed by catheter
angiography as per usual clinical practice.

2. Modified Rankin scale score of ≤3

3. Target area of stenosis in an intracranial artery that has a normal diameter of 2.00
mm to 4.50 mm

4. Target area of stenosis is ≤14 mm in length

5. Age ≥30 years and ≤80 years

* Patients 30 to 49 years of age are required to meet at least 1 additional criteria
(i-vi) provided below to qualify for the study. This additional requirement is to
increase the likelihood that the symptomatic intracranial stenosis in patients 30 to
49 years is atherosclerotic: i. Insulin-dependent diabetes for at least 15 years ii.
At least 2 of the following atherosclerotic risk factors: hypertension (BP ≥ 140/90 mm
Hg or on antihypertensive therapy); dyslipidemia (LDL ≥130 mg/dL or HDL ≤40 mg/dL or
fasting triglycerides ≥150 mg/dL or on lipid lowering therapy); smoking;
non-insulin-dependent diabetes or insulin-dependent diabetes of <15 years duration;
family history of any of the following: myocardial infarction, coronary artery bypass,
coronary angioplasty or stenting, stroke, carotid endarterectomy or stenting, and
peripheral vascular surgery in parent or sibling who was < 55 years of age for men or
< 65 for women at the time of the event.

iii. History of any of the following: myocardial infarction, coronary artery bypass,
coronary angioplasty or stenting, carotid endarterectomy or stenting, or peripheral
vascular surgery for atherosclerotic disease iv. Any stenosis of an extracranial
carotid or vertebral artery, another intracranial artery, subclavian artery, coronary
artery, iliac or femoral artery, other lower or upper extremity artery, mesenteric
artery, or renal artery that was documented by noninvasive vascular imaging or
catheter angiography and is considered atherosclerotic v. Aortic arch atheroma
documented by noninvasive vascular imaging or catheter angiography vi. Any aortic
aneurysm documented by noninvasive vascular imaging or catheter angiography that is
considered atherosclerotic

6. Negative pregnancy test in a female who has had any menses in the last 18 months

7. Patient is willing and able to return for all follow-up visits required by the
protocol.

8. Patient is available by phone.

9. Patient understands the purpose and requirements of the study, can make him/herself
understood, and has provided informed consent.

10. Demonstration of poor or no collateral flow in the territory of the qualifying
stenotic vessel (ASITN/SIR Collateral Flow Grades 0-2) and hypoperfusion of the
vascular territory in MRI.

Exclusion Criteria:

1. Tandem extracranial or intracranial stenosis (70-99%) or occlusion that is proximal or
distal to the target intracranial lesion

2. Bilateral intracranial vertebral artery stenosis of 70% to 99% and uncertainty about
which artery is symptomatic (e.g., if patient has pontine, midbrain, or temporal
occipital symptoms)

3. Stenting, angioplasty, or endarterectomy of an extracranial (carotid or vertebral
artery) or intracranial artery within 30 days before the expected enrollment date

4. Previous treatment of target lesion with a stent, angioplasty, or other mechanical
device, or plan to perform staged angioplasty followed by stenting of target lesion

5. Plan to perform concomitant angioplasty or stenting of an extracranial vessel tandem
to an intracranial stenosis

6. Presence of intraluminal thrombus proximal to or at the target lesion

7. Any aneurysm proximal to or distal to the stenotic intracranial artery

8. Intracranial tumor (including meningioma) or any intracranial vascular malformation

9. Computed tomographic or angiographic evidence of severe calcification at target lesion

10. Thrombolytic therapy within 24 hours before enrollment

11. Progressive neurologic signs within 24 hours before enrollment

12. Brain infarct within previous 30 days of enrollment that is of sufficient size (> 5
cm) to be at risk of hemorrhagic conversion during or after surgery

13. Any hemorrhagic infarct within 14 days before enrollment

14. Any hemorrhagic infarct within 15 to 30 days that is associated with mass effect

15. Any history of a primary intracerebral (parenchymal) hemorrhage

16. Any other intracranial hemorrhage (subarachnoid, subdural, or epidural) within 30 days

17. Any untreated chronic subdural hematoma >5 mm in thickness

18. Intracranial arterial stenosis related to arterial dissection, Moya-Moya disease; any
known vasculitic disease; herpes zoster, varicella zoster or other viral vasculopathy;
neurosyphilis; any other intracranial infection; any intracranial stenosis associated
with cerebrospinal fluid pleocytosis; radiation-induced vasculopathy; fibromuscular
dysplasia; sickle cell disease; neurofibromatosis; benign angiopathy of central
nervous system; postpartum angiopathy; suspected vasospastic process, and suspected
recanalized embolus

19. Presence of any of the following unequivocal cardiac sources of embolism: chronic or
paroxysmal atrial fibrillation, mitral stenosis, mechanical valve, endocarditis,
intracardiac clot or vegetation, myocardial infarction within 3 months, dilated
cardiomyopathy, left atrial spontaneous echo contrast, ejection fraction <30%

20. Known allergy or contraindication to aspirin and local or general anesthesia

21. History of life-threatening allergy to contrast dye. If not life-threatening and can
be effectively pretreated, patient can be enrolled at physician's discretion

22. Known absolute contraindication to obtaining MRI studies, such as magnetically
activated implanted devices (cardiac pacemakers, insulin pumps, neuro-stimulators, and
cochlear implants), MRI incompatible orthopedic implants, and free metallic fragments
in the brain or eye.

23. Active peptic ulcer disease, major systemic hemorrhage within 30 days, active bleeding
diathesis, platelets <100,000, hematocrit <30, INR >1.5, clotting factor abnormality
that increases the risk of bleeding, current alcohol or substance abuse, uncontrolled
severe hypertension (systolic BP>180 mm Hg or diastolic BP>115 mm Hg), severe liver
impairment (AST or ALT > 3 times normal, cirrhosis), creatinine > 3.0 (unless on
dialysis)

24. Major surgery (including open femoral, aortic, or carotid surgery) within previous 30
days or planned in the next 90 days after enrollment

25. Indication for warfarin or heparin beyond enrollment (NOTE: Exceptions allowed for use
of subcutaneous heparin for deep venous thrombosis prophylaxis while hospitalized)

26. Severe neurologic deficit that renders the patient incapable of living independently

27. Dementia or psychiatric problem that prevents the patient from following an outpatient
program reliably

28. Comorbid conditions that may limit survival to < 3 years

29. Females who are pregnant or of childbearing potential and unwilling to use
contraception for the duration of this study

30. Enrollment in another study that would conflict with the current study

Surgical Specific Exclusion Criteria:

In addition to those enumerated above, given the surgical nature of the intervention for
patients failing best medical therapy, the following are additional exclusion criteria:

1. Use of clopidogrel or extended release dipyridamole within 7 days of the date of
surgery. This exclusion is based on the elevated risk of hemorrhagic complications for
intracranial surgery using those agents according to the current AHA/ACC Guidelines
(Fleisher et al., 2007).

2. Evidence of active, un-treated focal or systemic infections (i.e. pneumonia, urinary
tract infection, skin abscess) or history of recurrent infections despite treatment in
the last 6 months.

3. Coagulation disorders characterized by a PTT ≥ 34, or a PT ≥ 12, or an INR ≥ 1.3, or a
platelet count of <80,000.

4. Non-controlled hyperglycemia (any pre-prandial glucose level ≥ 180 mg/dL in any single
test within 30 days before enrollment) or a hemoglobin A1c (HbA1c) ≥7%.

5. A low-density lipoprotein cholesterol (LDL-c) ≥ 130 mg/dL.

6. A non-high-density lipoprotein cholesterol (non-HDL-c) ≥ 100 mg/dL.

7. Smoking history in the last 6 months.

8. BMI ≥ 30 kg/m2