Comparison of Direct and Indirect Bypass for Moyamoya

Disease

Jared PisapiaMGH 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 T2- hyperintense 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 flape. dura mater

Direct Bypass: STA-MCA bypass

Baaj et al., 2009)

Matsushima et al., 1998

Combination:

b. posterior branch of the STA;

c. anterior branch of the STA;

f. temporal muscle; g. branch of the MCA; h. anastomosis

Direct and Indirect Bypass: STA-MCA Anastomosis + EMS.

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

EDAS MCI STA-MCAN 12 22 16

Collateral vessel formation

44% 52% 74%

Clinical improvement

56% 63% 74%

Complications 1 minor stroke 2 epidural hematomas

1 major & 1 minor stroke

• 50 patients with pediatric MMD, 76 hemispheres,

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

Conservative EDAS STA-MCAN 11 5 6Ischemic or rebleeding event

6 3 0

Stroke-free time (years)

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)• Useful if inadequate donor

artery grafts

• At least several weeks required to form collaterals

• Easier and safer in patients with serious medical comorbities

Direct (STA-MCA bypass)• Technically difficult; size and

progressive MCA occlusion

• Immediate revascularization

• 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

• Christopher S. Ogilvy, M.D.• Brian V. Nahed, M.D.• Brian P. Walcott, M.D.• Robert L. Martuza, M.D.• Neurosurgery Department