Experiences of Superficial Temporal Artery-middle Cerebral Artery (STA-MCA) Anastomosis in Children of so-called “Moyamoya” Disease

Abstract

Introduction of by-pass surgery has been a most important advance in the treatment of so-called “Moyamoya” disease in a last decade. According to statistical studies by Nishimoto and et al. (5, 6), such children with this disease manifest predominantly ischemic disorders such as TIA or infarction, both of which consist 68% of etiological mechanisms for the onset of the disease. Therefore, by-pass surgery seems to be indicated for children's Moyamoya disease reasonably well.
We experienced STA-MCA anastomosis in two cases of children with this disease.
Case 1 was a 23-months-old female with typical bilateral Moyamoya anomaly, for which she was done bilateral STA-MCA anastomoses. She was initially operated right side for completed stroke with moderate hemiplegia of the left face and extremities. Left STA-MCA anastomosis was done one month after the first surgery, because she got focal seizures on the right side followed by right postictal hemiplegia and aphasia for 4 hours. STA-MCA anastomosis was very effective, especially in right surgery for left completed stroke inducing rapid dramatic improvement of left hemiplegia. Angiographically, STAs were bilaterally patent two weeks after each surgery. Right surgery induced definite angiographical in-crease of cerebral circulation with dilatation of STA. Follow-up angiography revealed newly-formed vascular channels between dural arteries and cortical middle cerebral arteries with still patent anastomosis and further increase of circulation one year later. Only neuro-logical deficit of this patient is very slight restriction of fine movements of fingers of the left hand with increased deep tendon reflexes one year and seven months after surgery.
Case 2 was a 7-years-old school girl with stenosis of C₂ and C₁ of the right IC, right Al and right M₁, which was very much similar to the findings of Moyamoya disease except abnormal fine arterial networks of the base of the brain. Recurrent TTAs affected on the left extremities and face after crying required right STA-MCA anastomosis. However, C² of the right IC was occluded within two weeks after surgery with patent anastomosis. She had sensory TIAs affected on the left extremities a few times within a month postopera-tively. She has been free from TIAs or any neurological symptom for last 16 months after thelast attack. Right carotid angiography revealed widespread increase of cerebral circu-lation mainly due to newly-formed transdural anastomosis between branches of the middle meningeal artery and cortical middle cerebral arteries, even though STA-MCA anastomosis is still effectively patent one year after surgery.
As far as our operation is concerned, double anastomosis is a procedure of choice, because the stenotic trunk of the middle cerebral artery might restrict perfusion of blood within limited areas of anastomosed cortical branches of the middle cerebral artery. Al-though we did not perform encephalo-myo-synangiosis reported by Karasawa et al. (3), transdural anastomosis was developed remarkably in all cases with STA-MCA anastomosis. Preservation of the middle meningeal artery within an operative field seemed to be very important to produce transdural anastomosis.
Our experience indicates usefulness of STA-MCA anastomosis in the treatment of so-called “Moyamoya” disease, even if age of the patient is so young as 2-years-old.