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CASE REPORT

Successful treatment of a giant pediatric fusiform
basilar trunk aneurysm with surpass flow diverter
Peter Kan,1 Maxim Mokin,2 Ajit S Puri,3 Ajay K Wakhloo4,5
1

Department of Neurosurgery,
Baylor College of Medicine,
Houston, Texas, USA
2
Department of Neurosurgery
and Brain Repair, USF, Tampa,
Florida, USA
3
Department of Radiology,
University of Massachusetts,
Worcester, Massachusetts, USA
4
Department of Radiology,
New England Center for Stroke
Research and Division
Neuroimaging and
Intervention, Worcester,
Massachusetts, USA
5
Division of Neuroimaging and
Intervention, University of
Massachusetts Medical School,
Worcester, Massachusetts, USA

SUMMARY
Fusiform aneurysms present a unique challenge to
traditional microsurgical and endovascular treatment
because of the lack of a discernible neck and the
involvement of parent vessel. Flow diversion has
increasingly become the treatment of choice for fusiform
aneurysms in the anterior circulation, but its results in
the posterior circulation are variable. We report
successful treatment of a giant fusiform upper basilar
trunk aneurysm with the Surpass flow diverter in an
adolescent, and discuss the potential advantages of this
emerging technology in the treatment of fusiform
posterior circulation aneurysms.

Correspondence to
Dr P Kan, Department of
Neurosurgery, Baylor College of
Medicine, 7200 Cambridge St,
Suite 9B, Houston, TX 77030,
USA; peter.kan@bcm.edu

Pediatric intracranial aneurysms often have different morphologies and etiologies compared with
their adult counterparts.1–3 Previous reports
suggest that fusiform aneurysms originating from
dissection are more common in the pediatric population.1–3 Fusiform aneurysms present a unique
challenge to traditional microsurgical and endovascular treatment because of their morphology and
the involvement of the parent vessel. Recently, flow
diversion has been advocated as the treatment of
choice for fusiform aneurysms in the anterior circulation, but its results in the posterior circulation are
variable.4 5
In this report, we describe successful treatment
of a giant fusiform upper basilar trunk aneurysm
with the Surpass flow diverter (FD) in an adolescent, and discuss the potential advantages of this
emerging technology in the treatment of posterior
circulation aneurysms.

Accepted 23 April 2015

BACKGROUND

CASE PRESENTATION

To cite: Kan P, Mokin M,
Puri AS, et al. BMJ Case
Rep Published online:
[please include Day Month
Year] doi:10.1136/bcr-2015011718

The patient is a 16-year-old boy, previously healthy,
who presented with diplopia, ataxia, dysarthria,
dysphagia, and right hemiparesis. CT imaging of
the brain did not detect any subarachnoid hemorrhage, but MRI demonstrated multiple brainstem
and cerebellar infarcts and a partially thrombosed
upper basilar trunk aneurysm with mass effect
(figure 1). Digital subtraction angiography (DSA)
revealed a giant fusiform upper basilar trunk aneurysm with mild proximal stenosis (figure 2). The
patient underwent a complete rheumatology
workup for connective tissue disorder, including
serum markers and a lumbar puncture, that were
negative. The patient did not have a history of significant trauma. The aneurysm was considered not
amenable to conventional microsurgical and endovascular treatment, and flow diversion was offered

as an alternative. The variability of its efficacy in
posterior circulation aneurysms was fully discussed
with the patient and his parents.

TREATMENT
The patient was pretreated with dual antiplatelet
therapy, consisting of 325 mg of aspirin daily and
75 mg of clopidogrel daily for 5 days prior to the
procedure. The degree of P2Y12 inhibition and
aspirin response were tested with VerifyNow
(Accumetrics, San Diego, California, USA) on the
day of treatment. His aspirin response unit and
P2Y12 reaction units were 384 and 100, respectively, suggestive of an appropriate level of platelet
inhibition for treatment. The repeated test at
3 months showed continued stable inhibition.
Systemic heparin was administered to achieve an
activated clotting time of >250 s during the
procedure.
Under general anesthesia, bilateral femoral access
was obtained. To ensure robust proximal support
for FD deployment, a triaxial system consisting of a
Neuron MAX 088 guide catheter (Penumbra Inc,
Alameda, California, USA) in the right V2 segment
and a 5 F distal delivery catheter in the right V4
segment, was used. A 5 F diagnostic catheter was
placed in the left vertebral artery so that adequate
angiographic runs could be performed during FD
deployment. We navigated past the aneurysm with
an SL10 microcatheter (Stryker, Kalamazoo,
Michigan, USA) and a Synchro Standard wire
(Boston Scientific, Natick, Massachusetts, USA).
The microcatheter was then exchanged for a
3×25 mm Surpass FD (Stryker Neurovascular,
Fremont, California, USA), which was then
deployed starting from the left P1 segment. The
device did not fully cover the fusiform portion of
the aneurysm, and thus a second 3×25 mm device

Figure 1 MRI revealed multiple brainstem and
cerebellar infarcts, and a partially thrombosed upper
basilar trunk aneurysm with mass effect.

Kan P, et al. BMJ Case Rep 2015. doi:10.1136/bcr-2015-011718

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Figure 2 Digital subtraction
angiography (A, B) with
three-dimensional reconstruction (C)
showing giant fusiform upper basilar
trunk aneurysm with mild proximal
stenosis.

Figure 3 (A, B) Digital subtraction
angiography showing the final
construct with two 3×25 mm Surpass
flow diverters.

was deployed to overlap the first device in the fusiform segment
of the aneurysm. A 3.5×10 mm Neuroform stent (Stryker) was
then deployed to overlap the distal portion of the first device to
ensure patency of the left posterior cerebral artery (figure 3).
The microwire straightened the left P1 segment thus creating an
‘infolding’ or ‘pseudo’ stenosis of the artery just distal to the
Surpass device.
There was concern that when the wire was withdrawn, blood
flow may be compromised at the distal transition between
Surpass and the P1 segment if the vessel were to refold on itself
just distal to the Surpass device. The Neuroform stent was
deployed to allow a smooth transition between the FD and the
distal artery. A Neuroform stent was chosen over a short
Surpass device because of the lower cost associated with the
Neuroform stent and less metal coverage of the P1 segment and
its perforators compared with an additional FD.
DSA on postoperative day 1 showed no filling of the aneurysm and a patent construct. The patient remained in hospital
for a total of 6 weeks, 5 of which were for acute inpatient
rehabilitation. His postoperative course was uneventful and he
did not suffer any additional neurologic deficits.

patient was treated with daily dual antiplatelet therapy consisting of aspirin (325 mg) and clopidogrel (75 mg) for 6 months
after the procedure. Clopidogrel was then discontinued, and he
remained on an aspirin regimen (81 mg daily), which will be
continued throughout his life. After DSA at 1 year, we propose
non-invasive annual imaging with MRI (short echo time (TE)
with gadolinium-diethylenetriamine pentaacetic acid).

DISCUSSION
We have reported a case of successful treatment of a symptomatic
giant fusiform basilar aneurysm with the Surpass FD in an adolescent. The literature on the use of FD in the treatment of pediatric
cerebral aneurysms is sparse.6 7 Although the use of the Surpass
FD has been reported in the treatment of posterior circulation
aneurysms,8 its use has not been reported in pediatric patients in

OUTCOME AND FOLLOW-UP
At 6 months, the patient’s diplopia and dysphagia had resolved
(he never required a gastrostomy tube). He had residual dysarthria and ataxia but was ambulatory without assist. His right-sided
strength was normal, with only residual spasticity at 6 months.
His 6 month angiogram revealed that the aneurysm remained
obliterated and the construct remained patent with no stenosis
(figure 4). Follow-up CT at 4 months also showed an overall
reduction in aneurysm size and mass effect (figure 5). The
2

Figure 4 Angiogram obtained at the 6 month follow-up examination,
showing complete aneurysm obliteration and patent construct with no
stenosis.
Kan P, et al. BMJ Case Rep 2015. doi:10.1136/bcr-2015-011718

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and a larger patient population with longer follow-up is necessary to further assess the safety and efficacy of this emerging
device in the treatment of posterior circulation aneurysms.
Additional long term follow-up is also necessary to look for
recurrence and document cure in our patient.

Learning points

Figure 5 CT at 4 months (B) revealed overall reduction in aneurysm
size and mass effect compared with the initial postoperative study (A).
this location. FDs have been advocated as the firstline treatment
for fusiform aneurysms in the anterior circulation; however, the
results of flow diversion in the treatment of posterior circulation
aneurysms have uniformly been worse compared with anterior
circulation aneurysms.4 5 9 Phillips et al5 treated 32 posterior circulation aneurysms with the pipeline embolization device (PED)
and reported a permanent neurological complication rate of
9.4%, with perforator infarcts occurring in 14% of patients with
basilar artery aneurysms. Similar results have been reported in
the International Retrospective Study of the PED.4 In 55 posterior circulation aneurysms treated with a PED, Kallmes et al4
reported neurologic morbidity and mortality of 16.4% and an
ischemic stroke rate of 7.3%. Among posterior circulation aneurysms, fusiform basilar aneurysms appear to have the highest treatment risks, likely because of extensive involvement of brainstem
perforators.5 10
Surpass FD is an alternative FD that has received regulatory
approval in the European Economic Area and is undergoing
evaluation for approval in the USA. We believe that, compared
with the PED, the Surpass FD has several potential advantages
in the treatment of long fusiform basilar aneurysms, as in our
case. First, the Surpass FD is available in longer lengths (up to
50 mm), thereby potentially allowing the use of a single device
and minimizing the coverage of perforators. We originally
planned to use a single 4 mm device to minimize perforator
coverage (the longest 4 mm device is 50 mm). However, the
final measurement of the vessel distal to the aneurysm was only
2.6 mm and thus we decided to use a 3 mm device instead to
avoid a large mismatch. The longest 3 mm device currently is
25 mm, and to cover the aneurysm, a second device was
needed. Longer 3 mm devices in the future would eliminate this
problem. Second, compared with the PED, there is less device
foreshortening,8 especially in fusiform aneurysms where the
device will expand to nominal diameters with maximal foreshortening. With less foreshortening and more predictable
length of the device, it again reduces the need of telescoping
multiple devices, thus enhancing the chance of perforator
preservation.
Although our patient was treated successfully with an excellent clinical result, our case represents a single case experience,

Kan P, et al. BMJ Case Rep 2015. doi:10.1136/bcr-2015-011718

▸ Fusiform aneurysms present a challenge to traditional
surgical clipping or conventional endovascular coil
embolization because they lack a discernible neck and there
is circumferential involvement of the parent vessel.
▸ In the treatment of fusiform aneurysms, flow diversion offers
the advantage of endoluminal vessel reconstruction, leading
to aneurysm obliteration and healing of the parent vessel.
▸ The results of flow diversion in the treatment of posterior
circulation aneurysms have uniformly been worse compared
with anterior circulation aneurysms, likely due to perforator
rich zones.
▸ Nevertheless, in select cases, flow diversion can offer
successful treatment of fusiform aneurysms in the posterior
circulation.

Contributors Each of the authors contributed significantly to the preparation of
this case report.
Competing interests PK: consultant for Stryker Neurovascular, Covidien, and
Microvention. MM: education grant from Toshiba. ASP: consultant for Codman and
Covidien. AKW: consultant for Stryker Neurovascular; research grant from Philips
Healthcare and Wyss Institute; and speaker for Harvard Postgraduate Course and
Miami Cardiovascular Institute.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.

REFERENCES
1
2
3
4

5

6
7
8

9
10

Meyer FB, Sundt TM Jr, Fode NC, et al. Cerebral aneurysms in childhood and
adolescence. J Neurosurg 1989;70:420–5.
Ostergaard JR. Aetiology of intracranial saccular aneurysms in childhood. Br J
Neurosurg 1991;5:575–80.
Proust F, Toussaint P, Garnieri J, et al. Pediatric cerebral aneurysms. J Neurosurg
2001;94:733–9.
Kallmes DF, Hanel R, Lopes D, et al. International retrospective study of the pipeline
embolization device: a multicenter aneurysm treatment study. AJNR Am J
Neuroradiol 2015;36:108–15.
Phillips TJ, Wenderoth JD, Phatouros CC, et al. Safety of the pipeline embolization
device in treatment of posterior circulation aneurysms. AJNR Am J Neuroradiol
2012;33:1225–31.
Navarro R, Brown BL, Beier A, et al. Flow diversion for complex intracranial
aneurysms in young children. J Neurosurg Pediatr 2015;15:276–81.
Burrows AM, Zipfel G, Lanzino G. Treatment of a pediatric recurrent fusiform middle
cerebral artery (MCA) aneurysm with a flow diverter. J Neurointerv Surg 2013;5:e47.
Wakhloo AK, Lylyk P, de Vries J, et al. Surpass flow diverter in the treatment of
intracranial aneurysms: a prospective multicenter study. AJNR Am J Neuroradiol
2015;36:98–107.
D’Urso PI, Lanzino G, Cloft HJ, et al. Flow diversion for intracranial aneurysms:
a review. Stroke 2011;42:2363–8.
Siddiqui AH, Abla AA, Kan P, et al. Panacea or problem: flow diverters in the
treatment of symptomatic large or giant fusiform vertebrobasilar aneurysms.
J Neurosurg 2012;116:1258–66.

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Kan P, et al. BMJ Case Rep 2015. doi:10.1136/bcr-2015-011718