Talking about the diagnosis of smog disease and its surgical treatment
Department of Neurosurgery, Shandong Qianfo Mountain Hospital (Post 250014) Meng Xiang Jing
Smoker’s disease, also known as MoyaMoya disease, is a group of vascular diseases characterized by progressive stenosis or occlusion of the end of the internal carotid artery and its large branch vessels bilaterally, with the formation of an abnormal neovascular network at the base of the skull. The disease was first described in 1957 by Takeuchi and Shimizi in Japan, and was named MoyaMoya by Suzuki in 1969 because the cerebral angiogram showed many dense piles of small blood vessels that resembled smoke exhaled during smoking (as seen in the figure). The disease was first reported in China by Li Shuxin of Henan Medical College in 1976. China, Japan, Korea, Malaysia and other Asian countries are the countries with high incidence of smog. At present, the incidence of smog disease in China also shows a trend of increasing year by year, and the incidence in our province is higher in the southwest of Lu. Meng Xiangjing, Department of Neurosurgery, Shandong Qianfo Mountain Hospital
The exact etiology of the disease is still unclear and may be related to genetic, immune, inflammatory, abnormal cytokine secretion and abnormal accumulation of elastin.
Clinically, it is manifested in two categories: ischemic stroke attack and hemorrhagic stroke attack. Ischemic stroke is mainly manifested by cerebral infarction and transient ischemic attack; hemorrhagic stroke is mainly manifested by subarachnoid hemorrhage, ventricular hemorrhage, and cortical hemorrhage. The pathophysiological basis of hemorrhage is: first, rupture of dilated smoldering vessels, second, rupture and bleeding of tiny aneurysms, and third, rupture of large aneurysms near Willis ring. Patients mostly present with headache, dizziness, and weakness; limb movement disorders, hemianesthesia, speech and visual disorders, ataxia, and epilepsy. The incidence is higher in women than in men, 1.8:1. 10-40 years old is the high incidence age group; children are mainly affected by cerebral ischemic attacks; adult patients are mostly affected by cerebral hemorrhage, with a mortality rate of about 5% after the first hemorrhage and up to 25% for rebleeding. 10% of patients with smoldering disease have a family history.
Total cerebral angiography (DSA) is the gold standard for the diagnosis of smog. Other imaging and cerebral metabolic tests such as CT, CTA, MRI, MRA, PET, single photon emission tomography (SPECT), XeCT, and CT perfusion imaging are used in the diagnosis and preoperative and postoperative evaluation of the disease.
In 1969, Suzuki divided the disease into six stages based on its clinical progression and imaging findings to guide clinical diagnosis and treatment.
The first stage is the narrowing of carotid fork: the stenosis of the terminal bifurcation of the internal carotid artery with no other abnormalities.
Stage 2 is the initiatioin of the moyamoya: stenosis of the terminal bifurcation of the internal carotid artery and formation of smoke vessels at the base of the skull. Each of the thickened smoke vessels can be distinguished on angiography. There is no extracranial to intracranial collateral circulation formation.
Stage 3 is the intensification of the moyamoya: the anterior cerebral artery (ACA) and middle cerebral artery (MCA) are absent, and the smoke vessels are very obvious, forming a smoke vascular mass, and each artery forming the smoke vascular mass cannot be identified on angiography. The posterior cerebral artery (PCA) or posterior communicating artery is not affected, and no extracranial to intracranial collateral circulation is formed.
The fourth stage is the minimization of the moyamoya: the posterior communicating artery is congenitally slender or absent, and no normal PCA is visible at the beginning. the occlusion of the internal carotid artery has progressed to the union with the posterior communicating artery, and the posterior communicating artery that was once present on the imaging disappears in this stage. The smoky vessels have become coarse, and the vessels that make up the smoky mass have become thinner and have formed a less well-defined vascular network. There is an increase in the smoke vessels via the orbital artery and a gradual thickening of the arteries from the extracranial to the intracranial collateral circulation.
Stage 5 is the reduction of the moyamoya: all major arteries emanating from the internal carotid artery disappear completely, with less smoke than in stage 4, and the vascular network is worse and confined to the siphon. Occlusion of the internal carotid artery progresses more downward, with occlusion occurring above the C2 or C3 segment. The extracranial collateral blood supply is further strengthened.
Stage 6 is the disappearance of the moyamoya: the siphon segment of the internal carotid artery disappears completely, and the smoke that first appeared at the base of the skull also disappears completely, the blood supply from the internal carotid artery to the skull has completely disappeared, and only the collateral circulation from outside the skull into the skull is seen.
Therefore, conservative medical treatment for smog is basically ineffective. Once diagnosed, surgery should be performed as early as possible to increase cerebral collateral circulation and improve cerebral blood supply through intracranial and extracranial revascularization before irreversible neurological dysfunction occurs in brain tissue, thus restoring neurological function. The surgery is divided into three types of procedures: direct, indirect and combined.
1.Direct revascularization: direct superficial temporal artery-middle cerebral artery anastomosis (STA-MCA) direct occipital artery-middle cerebral artery anastomosis (OA-MCA).
2.Indirect revascularization: common ones are: encephalo-duro-arterio-myo-synangiosis (EDAMs), encephalo-myo-synangiosis ( encephalo-myo-synangiosis (EMS), encephalo-duro-arterio-synangiosis (EDAMs), encephalo-duro-arterio-synangiosis (EMS), and arterio-synangiosis (EDAS), encephalo-myo-synangiosis (EMS), encephalo-duro-synangiosis (EDAS), encephalo-duro-arterio-synangiosis (EOS), and cranial multiple drilling.
3. Direct-indirect combined revascularization.
EDAS surgery is widely used because of its wide indications, clear source of blood supply, easy operation, low risk, precise effect, and completion of compensation in 2 weeks to 3 months after surgery, especially suitable for children, and is the most common indirect revascularization surgery at present. The EDAS procedures for patients with smoldering disease carried out by the Department of Neurosurgery II of our hospital have all achieved satisfactory surgical and clinical results.
The prognosis of smoldering disease is closely related to the age of onset. According to statistics, the morbidity and mortality rate of adult patients is significantly higher than that of adolescents, in which the morbidity and mortality rate of brain hemorrhage caused by this disease is more prominent in adults, as high as 63%, but more than 60% of patients who receive treatment have a better prognosis. In conclusion, timely intracranial and extracranial revascularization surgery in patients with Moyamoya disease can increase blood supply to the brain, relieve cerebral ischemia symptoms and improve cognition in patients with Moyamoya disease, which has positive significance in preventing reoccurrence in patients with ischemic stroke and reducing rebleeding in patients with hemorrhagic stroke.