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
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)
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 EDASMCISTA-MCA N122216 Collateral vessel formation 44%52%74% Clinical improvement 56%63%74% Complications1 minor stroke2 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 ConservativeEDASSTA-MCA N1156 Ischemic or rebleeding event 630 Stroke-free time (years) 8.1 +/- 1.54.0 +/- 1.58.5 +/- 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