Comparison of Direct and
Indirect Bypass for Moyamoya
Disease
Jared Pisapia
MGH Neurosurgery Grand Rounds
September 23, 2010
Overview
• Moyamoya disease (MMD)
• Case presentation
– Clinical course
– Surgical approach (EDAS)
• Revascularization options
– Indirect
– Direct
• Evidence supporting revascularization techniques
www.brain-aneurysm.com
Moyamoya Disease (MMD)
• More common in Asian populations
– Incidence: < 1/100,000
• Bimodal age of presentation
– Pediatric (Ischemia)
– Adults (Hemorrhage)
• Treatment – Revascularization
Case Report
• JB is a 32 year old RH woman with PMH of
congenital rubella syndrome referred by PCP
to MGH ED for evaluation of R MCA stenosis
• Intermittent numbness: L facial (V2 and V3), R
finger/toe x 1 month
• Episodes increased in frequency over prior
year; lasting less than 20 min and resolving
spontaneously
Case Report
• Outpatient MRI
– multifocal stenoses in anterior and
posterior circulation
• PMH/PSH: as above
• Meds: OCP
• FH: Ischemic stroke, 72 year old father
• SH: clerk, non-smoker
CTA
• Multiple intracranial
stenoses
• Bilateral involvement of
the supraclinoid ICAs
and ICA terminus
• Near-occlusion of right
M1 segment with intact
flow distally
Brain MRI
• > 3 small DWI and T2hyperintense lesions
• Recent infarcts
• Embolic or low-flow
infarcts
• No evidence of ICH
Hospital course
• She was placed on ASA 81 mg daily and her
OCP was discontinued
• She was discharged without further symptoms
• Follow-up in Neurosurgery Clinic; scheduled
for EDAS for revascularization
Encephaloduroarteriosynangiosis
(EDAS)
• Transposition of a segment of superficial
temporal artery (STA) to surface of brain
• Formation of spontaneous anastomoses
between the arteries of the cerebral cortex,
dura mater, and the scalp
EDAS
HEAD
Multiple Burr Holes
Baaj et al., 2009
Indirect Bypass: EDAS
a. main trunk of
the STA
b. posterior
branch of the
STA
c. anterior branch
of the STA
d. galeal flap
e. dura mater
Direct Bypass: STA-MCA bypass
Baaj et al., 2009)
Direct and Indirect Bypass:
STA-MCA Anastomosis + EMS.
Combination:
b. posterior branch of the
STA;
c. anterior branch of the
STA;
f. temporal muscle;
g. branch of the MCA;
h. anastomosis
Matsushima et al., 1998
Additional Indirect Options
• EMAS = EDAS + EMS
• EDAMS = EMAS + dura (includes middle
meningeal artery)
• Multiple burr holes
Baaj et al., 2009; Chang SD, Steinber GK, 2010
Multiple Combined Indirect Bypass
a. main trunk of the STA; b. posterior branch of the STA; c. anterior branch
of the STA; d. galeal flap; e. dura mater; f. temporal muscle;
Matsushima et al., 1998
Indirect vs. Combined vs. Direct Bypass
• 50 patients with pediatric MMD, 76 hemispheres,
EDAS
MCI
STA-MCA
12
22
16
Collateral vessel 44%
formation
52%
74%
Clinical
improvement
56%
63%
74%
Complications
1 minor stroke
2 epidural
hematomas
1 major & 1
minor stroke
N
 Direct STA-MCA is associated with the greatest postoperative
collateral formation and clinical improvement
 EDAS and MCI were safer, and MCI caused formation of collaterals
in the ACA distribution and is best procedure in children
Matsushima et al., 1998
Rebleeding in Hemorrhagic MMD
• STA-MCA bypass in prevention of future stroke, including
rebleeding or ischemia
N
Ischemic or
rebleeding event
Stroke-free time
(years)
Conservative
11
6
EDAS
5
3
STA-MCA
6
0
8.1 +/- 1.5
4.0 +/- 1.5
8.5 +/- 1.3
 Recurrent ICH occurred less frequently in patients undergoing
STA-MCA bypass than those who underwent EDAS
 Authors recommend STA-MCA bypass over indirect bypass for
patients presenting with intracranial hemorrhage
Kawaguchi et al., 2000)
Adults vs. Pediatric; Ischemia
• 23 patients underwent indirect bypass
– 16 adults (mean 35, 20-59 years old)
– 7 children (mean 10, 3-16 years old)
• Good collaterals on postoperative angiography
– 7/7 pediatrics, 7/16 adults
 Advancing age decreases development of collaterals through
indirect bypass
 Direct bypass is main treatment option for patients > 40 years
Comparison of Direct versus Indirect
Indirect (EDAS)
Direct (STA-MCA bypass)
• Useful if inadequate donor
artery grafts
• Technically difficult; size and
progressive MCA occlusion
• At least several weeks
required to form collaterals
• Immediate revascularization
• Easier and safer in patients
with serious medical
comorbities
• Symptomatic cerebral
hyperperfusion, although
transient
Conclusions
• The most appropriate revascularization
procedure for patients with MMD is not fully
defined.
• Case series are limited by inadequate power,
selection bias, and inherent differences in
patient characteristics.
• Choice of procedure may depend on surgeon’s
experience, nature of symptoms, and patient
age.
References
• Baaj AA, Agazzi S, Sayed ZA, Toledo M, Spetzler RF, van Loveren H: Surgical
management of Moyamoya disease: a review. Neurosurg Focus 26(4):E7,
2009
• Kawaguchi S, Okuno S, Sakaki T: Effect of direct arterial bypass on the
prevention of future stroke in patients with the hemorrhagic variety of
moyamoya disease. J Neurosurg 93:397-410, 2000.
• Matsushima T, Inoue T, Ikezaki K, Matsukado K, Natori Y, Inamura T, et al:
Multiple combined indirect procedure for the surgical treatment of
children with moyamoya disease. A comparison with single indirect
anastomosis with direct anastomosis. Neurosurg Focus 5(5):4, 1998
• Mizoi K, Kayama T, Yoshimoto T, Nagamine Y.:Indirect revascularization for
moyamoya disease: is there a beneficial effect for adult patients? Surg
Neurol 45:541-9, 1996.
• Starke RM, Komotar RJ, Connolly ES: Optimal surgical treatment for
moyamoya disease in adults: direct versus indirect bypass. Neurosurg
Focus 26(4):E8, 2009.
Acknowledgements
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Christopher S. Ogilvy, M.D.
Brian V. Nahed, M.D.
Brian P. Walcott, M.D.
Robert L. Martuza, M.D.
Neurosurgery Department