What Is Brain AVM?

Cerebral arteriovenous malformations, also known as cerebral hemangiomas, vascular hamartomas, and cerebral arteriovenous fistulas, are a congenital variation in the development of local cerebral blood vessels. The lack of capillaries between the cerebral arteries and cerebral veins at the diseased site causes The arteries are directly connected to the veins, forming a short circuit between the cerebral arteries and veins, resulting in a series of cerebral hemodynamic disorders. Cerebral arteriovenous is a group of abnormally developed blood vessels, including arteries and veins. There are multiple arteriovenous connections directly, without capillaries in the middle. Vascular clusters vary in size, most commonly found at the junction of gray and white matter, and are cone-shaped. The base is located in the cortex, with the tip pointing deep into the white matter. There are one or more thickened blood supply arteries, and the drainage veins are dilated and distorted. Degenerate brain tissue is mixed between deformed blood vessels, which is one of its pathological characteristics. A series of hemodynamic changes caused by cerebral arteriovenous malformations are mainly manifested in reduced local cerebral arterial pressure, increased venous pressure, and other disturbances in blood supply to the brain and intracranial hemorrhage. Cerebral ischemia caused by "brain stolen blood" in the brain, intracranial Pressure increase.

Cerebral arteriovenous malformations, also known as cerebral hemangiomas, vascular hamartomas, and cerebral arteriovenous fistulas, are a congenital variation in the development of local cerebral blood vessels. The lack of capillaries between the cerebral arteries and cerebral veins at the diseased site causes The arteries are directly connected to the veins, forming a short circuit between the cerebral arteries and veins, resulting in a series of cerebral hemodynamic disorders. Cerebral arteriovenous is a group of abnormally developed blood vessels, including arteries and veins. There are multiple arteriovenous connections directly, without capillaries in the middle. Vascular clusters vary in size, most commonly found at the junction of gray and white matter, and are cone-shaped. The base is located in the cortex, with the tip pointing deep into the white matter. There are one or more thickened blood supply arteries, and the drainage veins are dilated and distorted. Degenerate brain tissue is mixed between deformed blood vessels, which is one of its pathological characteristics. A series of hemodynamic changes caused by cerebral arteriovenous malformations are mainly manifested in reduced local cerebral arterial pressure, increased venous pressure, and other disturbances in blood supply to the brain and intracranial hemorrhage. Cerebral ischemia caused by "brain stolen blood" in the brain, intracranial Pressure increase.

Chinese name

AVM

Foreign name

arteriovenous malformations

Introduction

A congenital cerebrovascular disease

Square

Lack of capillaries in some arteries and veins of the brain

Shape

Mostly wedge-shaped with its tip pointing to the lateral ventricle.

which performed

Repeated intracranial hemorrhage, convulsions,

AVM I. Clinical symptoms

Clinically the male to female ratio is 2: 1. It is most common between the ages of 21 to 30, and 80% of the population is 11 to 40 years old. Common symptoms are intracranial hemorrhage, partial or systemic seizures, headache, transient ischemic attack and progressive neurological dysfunction, mental retardation, and intracranial murmur.

AVM 2. Differential diagnosis

At present, the main methods for clinical diagnosis of brain AVM include CTA, MRA and DSA. Today, DSA is still the "gold standard" for diagnosing brain AVM. It can not only qualitatively diagnose brain AVM, but also clarify its location, depth, range, size of deformed blood vessel clusters, the relationship between blood supply arteries and the trunk, and the number and distribution of drainage veins. The direction of blood flow can also be discriminated. Superselective intubation angiography can deeply understand the characteristics of vascular separation, and can be used for embolization.

In recent years, CTA has been widely used in clinical applications. Compared with DSA, CTA is non-invasive, has a small amount of radiation, short examination time, and has powerful post-processing software and a variety of post-processing methods. It can provide information about the external structure of blood vessels and provide more clinical help. Its diagnostic results and DSA Have a higher compliance rate.

MRI is not affected by skull artifacts, and it is significantly better than CT in diagnosing posterior cranial fossa brain AVM. It can clearly show the location, shape, size, internal structure of the lesion, and the adjacent relationship with important neural structures around the lesion. Ischemic, infarcted and softened foci due to stealing blood effect.

AVM III. Treatment Principles

1.Microsurgery

Microsurgical removal of the malformed vascular mass. According to the preoperative imaging data, the shape and location of the deformed blood vessel group, the blood supply artery and the reflux vein were determined, and the best surgical approach was used to open the skull.

2. Embolization

General anesthesia, heparinization of the whole body, NBCA glue, Onyx glue and spring coil and other materials were used to embolize arteriovenous malformations. When using Onyx gel embolism, if Onyx gel is found to flow back to the blood supply artery, stop the injection and continue the injection 2 minutes later. Through multiple "injection-dispersion-reflux-pause-re-injection", Onyx gel is continuously dispersed in the deformed blood vessel Until the target deformity group is embolized. During the operation, the embolization rate is determined according to the vascular structure of the lesion, the number of blood supply arteries, and the vascular conditions.

Nowadays, microsurgery is the most important method for treating AVM in the brain. It can clear the lesions quickly and thoroughly, and it is the most accurate and effective way to cure huge AVM. The basic principle of brain AVM surgery is to completely remove the malformed blood vessel mass and minimize brain tissue damage. The scope of exposure during the operation should be sufficient, and the craniotomy flap is larger than the lesion area shown on the imaging examination. According to the imaging findings, the origin of the blood supply arteries and the anatomical relationship between the deformed blood vessel group and the brain tissue are guided, and the blood supply arteries are processed first, and then the drainage veins are processed. During the operation, the deformed blood vessel was closely adhered to the ring-shaped resection lesion, and the relatively large blood-supplying arteries were temporarily clamped by the aneurysm clip. During the operation, the blood pressure was controlled to reduce.

Intravascular embolization is relatively convenient and minimally invasive. The embolization rate is related to malformed vascular structure, the number of blood supply arteries, and vascular conditions. Small, single-supply brain AVM can be completely embolized at one time, and small and medium lesions can be completely embolized and cured. Residual lesions that are not completely embolized can choose microsurgery or radiation therapy. Small AVM in the deep brain, using Onyx gel or NBCA gel for embolization treatment, can obtain good results.