TECHNICAL CASE REPORTS
Elad I. Levy, M.D.
Department of Neurosurgery
and Toshiba Stroke Research Center,
School of Medicine
and Biomedical Sciences,
University at Buffalo,
State University of New York,
Buffalo, New York

Robert D. Ecker, M.D.
Department of Neurosurgery
and Toshiba Stroke Research Center,
School of Medicine
and Biomedical Sciences,
University at Buffalo,
State University of New York,
Buffalo, New York

Ricardo A. Hanel, M.D., Ph.D.
Department of Neurosurgery
and Toshiba Stroke Research Center,
School of Medicine
and Biomedical Sciences,
University at Buffalo,
State University of New York,
Buffalo, New York

Eric Sauvageau, M.D.
Department of Neurosurgery
and Toshiba Stroke Research Center,
School of Medicine
and Biomedical Sciences,
University at Buffalo,
State University of New York,
Buffalo, New York

J. Christopher Wehman,
M.D.
Department of Neurological Surgery,
University of Miami
School of Medicine,
Miami, Florida

Lee R. Guterman, Ph.D., M.D.
Department of Neurosurgery
and Toshiba Stroke Research Center,
School of Medicine
and Biomedical Sciences,
University at Buffalo,
State University of New York,
Buffalo, New York

L. Nelson Hopkins, M.D.
Department of Neurosurgery
and Toshiba Stroke Research Center,
School of Medicine
and Biomedical Sciences,
University at Buffalo,
State University of New York,
Buffalo, New York
Reprint requests:
L. Nelson Hopkins, M.D.,
University at Buffalo Neurosurgery,
3 Gates Circle,
Buffalo, NY 14209.
Received, February 23, 2005.
Accepted, May 13, 2005.

ACUTE M2 BIFURCATION STENTING FOR CEREBRAL
INFARCTION: LESSONS LEARNED FROM THE HEART:
TECHNICAL CASE REPORT
OBJECTIVE AND IMPORTANCE: Acute ischemic stroke is the third leading cause of
death in the United States. For patients with NIHSS scores ⬎10 and evaluated within
6 hours, intra-arterial thrombolysis is the treatment of choice. The Merci retriever
(Concentric Medical Inc., Mountain View, CA) and IV TPA are currently the only
FDA-approved treatments for acute ischemic stroke. For patients who do not meet the
criteria for TPA administration and/or in whom the Merci device fails, options are
limited. Intracranial stenting for acute ischemic stroke after failed thrombolysis is now
possible because of improved delivery systems and appropriately sized stents.
CLINICAL PRESENTATION: A 26-year-old woman presented with an NIHSS score of
11 (right-sided hemiparesis and mixed aphasia) 4 hours from the time of symptom
onset. CT perfusion demonstrated increased time to peak in the entire left hemisphere;
conventional angiography demonstrated a left M1 occlusion.
INTERVENTION: After crossing the occlusion with a microcatheter, reteplase (2 units)
was administered into the clot. Mechanical thrombolysis was then attempted, without
restoration of flow. Two 3 ⫻ 12-mm coronary stents were placed from the M1 into the
superior and inferior divisions, respectively, with complete restoration of flow (TIMI 3).
Within 72 hours, the patient had an NIHSS score of 1, with a small infarction in the
external capsule.
CONCLUSION: Novel stroke interventions need to be developed for patients with
acute ischemic stroke in whom traditional interventions fail. We present (to our
knowledge) the first case of successful revascularization of an acute M1 occlusion
accomplished with placement of two coronary stents.
KEY WORDS: Acute stroke, Intracranial stenting, Ischemic stroke
Neurosurgery 58:588, 2006

T

DOI: 10.1227/01.NEU.0000197522.11613.0C

reatment for acute MI has undergone a
remarkable and steady intellectual progression over the last 15 years. Patients
with acute MI were initially treated with IV
streptokinase and TPA. Although thrombolytic therapy was attempted, many patients
did not benefit. Direct intra-arterial (IA) intervention with angioplasty and subsequently
with stent-assisted angioplasty in conjunction
with thrombolytic and antiplatelet therapy is
now standard of care for patients with acute
MI. Stenting has reduced restenosis rates and
provided a framework to maintain patency in
arteries recanalized with angioplasty alone.
IA stroke intervention is still in its infancy.
The first device for IA intervention in stroke,

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the Merci retriever, was approved by the FDA
in 2004 (5). Each year, 700,000 patients have a
cerebral infarction, and less than 2% receive IV
or IA therapy. For patients with NIHSS scores
⬎10 who are not treated with IV therapy, the
relative odds of a functional recovery is lowered by 75% (1). IA stroke intervention results
in successful, sustained recanalization of the
thrombosed artery in only 50% of patients;
repeated occlusion occurs in 17% of vessels
initially opened with mechanical clot disruption and/or thrombolytic agents (12). Nevertheless, results of the Prolyse in Acute Cerebral Thromboembolism studies (4, 6) suggest
that IA therapy is of benefit in patients with
high NIHSS scores. Stenting of intracranial

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ACUTE M2 BIFURCATION STENTING FOR CEREBRAL INFARCTION

vessels after failed thrombolytic therapy provides an intriguing alternative and might parallel the cardiac experience, although ischemic stroke tends to result from emboli, whereas
coronary vessel occlusions most often result from underlying
stenoses. Although stents designed for intracranial use may
not have enough radial outward force to open and support an
intracranial vessel, balloon-mounted cardiac stents are available that can be appropriately sized and navigated for this
purpose. In this report, we describe what is, to our knowledge,
the first successful deployment of two balloon-mounted cardiac stents in the left M2 branches at a bifurcation in a kissing
configuration, which led to vessel recanalization after failed
thrombolytic therapy.

CASE PRESENTATION
A 26-year-old woman was transferred to our institution
with a four-hour history of right-sided hemiplegia and fluctuating aphasia. The patient was a smoker in previously good
health and was not taking oral contraceptives. Neurological
examination confirmed the right-sided hemiplegia and a
mixed aphasia (NIHSS 11). A noncontrast head CT scan demonstrated only a subtle linear hypodensity in the region of the
lateral insular cortex. CT perfusion imaging revealed an increased time to peak (delayed or reduced flow) in the entire
left hemisphere.
Cerebral angiography revealed a proximal left MCA occlusion.
A 6-F guide catheter was inserted into the distal left internal
carotid artery. A Prowler Plus microcatheter (Cordis, Miami
Lakes, FL) coaxially loaded over a 0.14-inch PVS exchange-length
microwire was used to cross the lesion and was directed into the
inferior M2 division. The catheter was progressively pulled back
into the M1 while 2 units of reteplase was injected. Mechanical
clot perturbation with the wire and the catheter was also performed. Control imaging confirmed persistent occlusion. The
catheter was then exchanged for a 3 ⫻ 12-mm Vision balloonmounted stent (Guidant, Indianapolis, IN) that was deployed
slowly in the inferior division at subnominal pressure (1 atm/30
s to 4.5 atm), with complete recanalization of the division. An IV
bolus of eptifibatide was given (because the patient was not yet
therapeutic on clopidogrel and required potent antiplatelet medication to maintain patency of the newly deployed stent) and the
occluded superior M2 division was crossed with a 0.014-inch
PVS microwire (Boston Scientific, Natick, MA). Mechanical
thrombolysis with a Maveric 3 ⫻ 9-mm balloon (Medtronic AVE,
Santa Rosa, CA) was performed from the M2 to the M1. Transient recanalization occurred, with subsequent reocclusion after
several minutes. A second Vision 3 ⫻ 12-mm balloon-mounted
stent was positioned in the superior M2 (Fig. 1). Slow, subnominal inflation (1 atm/30 s to 4.5 atm) resulted in complete recanalization of the M2 division (TIMI 3 flow) (Fig. 2, A and B). The
postprocedure head CT scan demonstrated contrast material in
the previously noted region of hypodensity in the lateral insular
cortex. This region corresponded to the patient’s only residual
stroke burden. The patient was discharged home on hospital Day
4 with a subtle expressive aphasia and complete motor recovery.

NEUROSURGERY

FIGURE 1. Unsubtracted anteroposterior image with the first balloonexpandable stent deployed in the inferior division of the M2 and the second balloon-expandable stent deployed in the superior division with the
balloon and microwire still in place.

FIGURE 2. A, angiogram after deployment of stents in the M2 divisions
of the MCA with both M2 divisions filling without delay or evidence of
thrombus; B, anteroposterior unsubtracted angiogram with stents deployed
in a kissing configuration in the M2 divisions.

She was reevaluated in our office 1 week later and did not
demonstrate any neurological deficits (NIHSS ⫽ 0).

DISCUSSION
Endovascular treatment of acute stroke is a novel field, still
in its infancy stage of development. IA thrombolytic therapy
for acute stroke, although not FDA approved, has been shown
to be efficacious in several trials (4, 6, 9, 11). For occlusions that
remain recalcitrant to pharmacologic thrombolysis, IA mechanical thrombolysis may be initiated. Currently, the Merci
retriever is the only approved device for recanalization of IA
occlusions during acute stroke treatment (8).
At our institution, patients who present more than three
hours after the onset of stroke symptoms or have NIHSS
scores ⱖ10 receive angiograms and are treated with IA therapy (if the CT scan and perfusion studies document no evidence of frank or developing infarction over regions ⬎3 cm).
In the case presented, the vessels remained occluded, despite
administration of reteplase directly into the occlusion and
mechanical clot perturbation. For this reason, we elected to

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LEVY ET AL.

attempt mechanical thrombolysis using stent-assisted angioplasty (the Merci retriever was unavailable at the time of
treatment). The rationale for using the stent was that occlusive
clot, which becomes morselized by the angioplasty balloon, is
then held in place against the vessel wall by the stent struts
(10). By using extremely slow inflation techniques at a rate of
1 atm per 30 seconds, the vessel is able to accommodate slight
dilatation, which may be caused by the stent pressing thrombus against the intima and decrease the likelihood of rupture.
Additionally, the stents are deployed at pressures well below
nominal pressure (4.5 atm, as opposed to 8 or 10 atm), resulting in deployment of the stent at two-thirds of the intended
diameter (deployment is estimated to be 2.5–2.8 mm, rather
than 3 mm). This, in turn, leads to a reduction in the relative
porosity of the stent, making it less likely for thrombus to
extrude back through the stent and cause acute reocclusion.
When performing angioplasty alone, we have frequently
found that thrombus recurs and occludes the vessel minutes
after angioplasty. This may be caused by local platelet activation from existing thrombus and by intimal damage from the
angioplasty balloon. In the case presented here, intimal injury
may have occurred during attempts to recanalize the superior
division after initial stenting of the inferior division of the
MCA, thus necessitating stenting of the superior division.
Stenting of bifurcation lesions has been described for coronary atherosclerotic disease but not for intracranial pathological conditions. Stenting of coronary lesions at or near bifurcations for the treatment of atherosclerotic disease remains
challenging (3). Suggestions have been given for T, Y,
reverse-Y, and numerous other stent-configuration techniques
(3). Even dedicated bifurcation stents have been developed
and studied (14). A study was performed to compare two
specific techniques: simultaneous deployment of bifurcation
(or kissing) stents and provisional stenting of the side branch
following stenting of the main vessel (13). Simultaneous deployment of stents at a bifurcation, as described in the coronary literature, requires that the diameter of the vessel proximal to the bifurcation be greater than two-thirds the
aggregate diameter of the two stents (13). The stents should be
sized to the diameter of the branch vessels. The more conventional technique for stenting of coronary bifurcation lesions
involves placing a wire in each of the branch vessels, deploying the first stent in the main branch, and then advancing the
second stent over the wire, through the first stent, into the
other branch should revascularization of the second branch be
required (13). The incidence of in-hospital and 30-day major
adverse cardiac events, the need for target lesion revascularization, and procedure time were reduced using the simultaneous deployment technique. Others have found significantly
higher rates of permanent or transient side-branch compromise with sequential balloon angioplasty than with the simultaneous angioplasty technique (33% versus 0%, respectively; P
⫽ 0.003) (2).
For intracranial occlusions or stenoses, clinicians are limited
by the lack of stents sized appropriately to accommodate
MCAs. For deployment in the MCA, a stent must be suffi-

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ciently pliable and navigable to traverse the carotid siphon
and the turn into the M1 portion of the MCA. The Vision stent
is one of the most navigable coronary stents currently available, but it is not appropriately sized for 2-mm vessels. The
smallest available Vision stent is 3 mm in diameter; therefore;
we could not perform a simultaneous deployment strategy, as
the two stents together would be oversized for the M1 portion.
Additionally, because the stent would have to be deployed at
a subnominal diameter (thus reducing stent porosity), the
navigation of a second stent through the pores of the first stent
would be extremely challenging.
In our case, deployment of the first stent predominantly in
the M2, with minimal overhang into the M1, allowed enough
room for the second stent to be placed into the superior
division without compromising or compressing the first stent.
Before placing a second stent in the superior division, multiple
attempts were made at angioplasty, but vessel reocclusion
occurred within a few minutes. This necessitated the placement of the second stent, and permanent patency was
achieved.
The realization that a second stent would likely be needed,
in addition to the possibility of thrombus migration into the
superior division as a result of ⬙snowplowing⬙ from the first
stent, should have prompted the use of a second wire placed
in the superior division before deployment of the first stent
(7). This would have enabled continued access to the superior
division even if the first stent was suboptimally deployed and
obstructed the ostia of the superior division. Although stenosis or occlusion at or near coronary bifurcations accounts for
15 to 18% of all percutaneous coronary interventions, this
occurrence is relatively rare in the intracranial circulation (7).
We can apply the technique from coronary experience but are
likely dealing with a different entity. In the intracranial circulation, most ischemic strokes result from embolic disease;
whereas in the coronary circulation, occlusions tend to result
from plaque rupture of underlying stenoses. For future cases,
provisional stenting of the second division would be performed after microwire access to both divisions had been
confirmed and successful stent-assisted recanalization of the
first division had been determined.

CONCLUSION
Acute stroke intervention is an exciting and dynamic field.
There are many lessons to be learned from the vast cardiology
and peripheral vasculature literature. We describe a novel
procedure of stent-assisted recanalization of the MCA bifurcation during an acute stroke that is based on modifications of
previously described techniques in the coronary literature.
Stent positioning in the MCA bifurcation during deployment
of the initial stent is critical for allowing passage of the second
stent. Although not described in this report, the use of two
microwires, each placed in one of the M2 branches before
placement of the first stent, ensures continued access of both
vessels throughout the procedure. The use of stent-assisted
revascularization for acute stroke remains controversial. More

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ACUTE M2 BIFURCATION STENTING FOR CEREBRAL INFARCTION

experience with these techniques is needed to gain further
insight into the safety, durability, and appropriate indications
for this technique.

REFERENCES
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283:1145–1150, 2000.
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vs. kissing balloon angioplasty for stenting of bifurcation coronary lesions.
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COMMENTS

L

evy et al. describe their experience in treating a 26-year-old woman
who presented with a left middle cerebral artery occlusion. Four
hours from the time of onset, computed tomographic perfusion was
performed to increase transit time of the entire left hemisphere, and
conventional angiography demonstrated a left M1 occlusion. Despite
mechanical and pharmacological thrombolysis using Reteplase, restoration of flow could not be achieved. In paralleling experiences from
the cardiac literature, two 3 x 12 mm coronary stents were placed in
the M1 segment into the superior and inferior divisions and were only
inflated with nominal inflation pressure to 4.5 atmospheres. Remarkably, flow was established and maintained. As the authors report,
without stent assistance, this procedure often results in re-occlusion in
an acute fashion.
There is absolutely no question that novel concepts and applications to the cerebral circulation of lessons learned from the cardiac
literature are directly applicable. As experience increases and our
tools improve, these procedures will become commonplace and will
be able to be achieved with less risk. The potential population, as the
authors allude, is enormous, and we face the challenge in neurosurgery of training individuals to be able to deal with this overwhelming
problem when this becomes the standard of care. The authors are to be
congratulated, once again, in providing us with new concepts to treat
these very devastating disorders.
Robert H. Rosenwasser
Philadelphia, Pennsylvania

T

his case report documents the successful use of superior and
inferior division middle cerebral artery stents for the acute revascularization of occlusion refractory to low dose intra-arterial tissue
plasminogen activator and mechanical clot disruption attempts. This
technique has been described in the interventional cardiology literature, and the authors decided to use the two-stent procedure after
thrombolysis and angioplasty failed. An excellent result was obtained
with only a small infarction in what was likely to be a devastating
event in a young woman.
Given limited Food and Drug Administration-approved endovascular options for acute stroke, such innovative approaches are performed with varying degrees of success and complication rates. Technological advancements such as the cobalt chromium stent and lowerprofile, smaller delivery systems will allow endovascular surgeons to
perform more distal stenting procedures. The long-term effect of
stents in such small intracranial vessels is unknown. What role will
drug delivering stents play in the brain? What anti-platelet drugs will
be necessary, and for what length of time? Should mechanical clot
retrieval devices or primary stent angioplasty be front-line attempts
for acute vascular occlusion? Reports such as these raise more questions than they answer, but the successful treatment of this patient will
advance the field by inspiring investigation of these questions.
Sean D. Lavine
New York, New York

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