[Operative neurosurgery: personal view and historical backgrounds (9) Moyamoya angiopathy (MMA): past history and status presens].

The second international meeting on the Moyamoya angiopathy (MMA) was held in mid. July 2011 at the children's hospital Zurich by Frau PD Dr.Khan and Prof.Meuli. On this occasion I was asked to give a survey of this disease, so the following points were presented and discussed: 1. Who was the person who discovered this disease. 2. How has the Research Committee of the Ministry of Health and Welfare, Japan (RCMHWJ) contributed to clarify the epidemiology, etiology, pathophysiology and treatments. 3. What is the current situation in foreign countries especially Euroamerican to date on these topics. 4. How the treatment technique developed and who did the initial revascularization procedures for the first. 5. Update of the disease. 1. Established view; discovery of the disease by Tekeuchi and Shimizu in 1955 could have been called somewhat into question as they described neither abnormal vasculature nor transdural anastomosis. Kudo who described "spontaneous occlusion of the circle of Willis" more precisely, but seemed to have thought that the occlusion site of the internal carotid artery (ICA) is around the origin of the ophthalmic artery. Suzuki and Takaku who coined the name Moyamoya disease (MMD) in 1969 and described 6 stages of progression on the basis of observation on 20 cases. 2. The RCMHWJ founded in 1977 has contributed to clarifying the epidemiology, pathophysiology, treatment and etiology by interdisciplinary cooperative study having some epoch making events especially; (1)by setting the guide lines -diagnostic criteria of the disease at the end of 1970, (2)applying MRI and MRA at the beginning of 1990 for the diagnosis instead of angiography used until then. (3)By finding and focusing, therefore, on the cases of asymptomatic or oligosymptomatic presentation around the middle of 2000, which have almost doubled or tripled in incidence and/or prevalence and also changed the age distribution with the higher peak for adult cases. Achievements of research for the etiology and pathophysiology by genetics and molecular biology have enabled the discovery of basic FGF and other cytokines-angiogenetic factors and recently the genetic linkage site 17q25.3 in relation to the familiar incidence. Pathological studies verified by molecular biological methods have indicated that the vascular occluding process with intimal proliferation with thrombus formation does not occur only at the carotid fork originally researched intensively, but also at more distal parts of the cerebral arteries which could be verified with the help of molecular biology. 3. Occurrence but less incidence of the disease in the Euroamerican countries had already been noticed at the beginning of 1970 and its reason has been researched and discussed intensively in relation also to the etiology of the disease. 4. The first extracranial-intracranial (EC-IC) bypass surgery for a case of cerebral ischemia of the disease might have been carried out by Prof.Yaşargil and Prof.Reichman independently around the end of 1972. The indirect revascularization methods such as EMS, EDAS are now combined with or without EC-IC bypass to augment cerebral blood flow (CBF) of the hemodynamically compromised territory not only of the MCA, but also of the ACA and PCA. The big disadvantage of indirect revascularization might be the large size of the craniotomy necessitated for the purpose, which would decrease CBF of the brain surface. The author is doing multiple bypass procedures (bilateral EC-IC bypass plus STA-ACA bypass) in one session in accordance with the findings of CBF examination with small craniotomies. Prevention of rebleeding by revascularization is still under study but its results should be scrutinized on the basis of various etiologies and sites of the bleeding. 5. Besides some increase of epidemiological knowledge of asymptomatic or oligosymptomatic cases and of etiological molecular biological and genetic linkage studies, clinically, the mechanism of contralateral ischemia in patients in whom one side is operated upon or/and hyperperfusion after revascularization and its prevention seems to be one of main topics in recent journals.