Is the success rate of cerebrovascular malformation surgery high?

Cerebrovascular malformation is a congenital abnormality in the development of blood vessels. It can cause epilepsy and requires timely surgical treatment to improve the disorders in the nervous system. The success rate of the operation depends on the hospital, level and scientific nature of the operation.

1. Preparatory surgery

For surgeries where the carotid artery and its branches supply arteries to cerebral arteriovenous malformations, when it is necessary to control the blood supply to the carotid artery during the operation, the patient should lie in the supine position with the head turned to the healthy side. After local anesthesia, a longitudinal incision was made along the anterior edge of the sternocleidomastoid muscle at the plane of the thyroid cartilage. Incise the platysma muscle, pull the sternocleidomastoid muscle outward, incise the carotid sheath, separate the internal carotid artery, and bypass it with a rubber loop without blocking its blood flow for the time being. The incision is stuffed with dry gauze to protect it and to temporarily control bleeding if necessary during the operation.

2. Body position and incision (taking the more common frontal and parietal lesions of the cerebral hemisphere as an example) The patient lies on his side and a large horseshoe-shaped incision is made on the frontal and parietal regions [Figure ⑴]. The precentral gyrus should be exposed in the front and the entire lesion should be included in the surgical field of view. The midline of the incision is on the sagittal line to expose the longitudinal fissure of the cerebral hemisphere.

3. Craniotomy

The scalp and skull flap are treated routinely, but the following points should be noted: ① Bleeding in the scalp and skull is often heavy, sometimes resembling a meningioma, so the scalp should be incised in sections and bleeding should be stopped carefully; the scalp and skull flap can be opened separately. ② If the large blood vessels in the anterior central gyrus are obviously adhered to the dura mater, do not force it open; a small piece of dura mater can be left behind [Figure ⑵]. ③ If the blood vessels have been torn when the bone flap was opened, compress them with a small piece of muscle or gelatin sponge and suture them to the dura mater [Figure ⑶]. Do not ligate the blood vessels, otherwise hemiplegia or epilepsy may occur after the operation. ④ After the scalp bone flap is formed, apply bone wax to the bleeding edge of the bone window, and cover the bleeding veins and arachnoid granules with brain cotton to stop bleeding and prevent air embolism formation.

4. Identification of the Central Gyrus and its Supplying Arteries

Determining the motor area based on anatomical location alone is not accurate enough and can be identified using an electrical stimulator. The diameter of the main blood supply artery is thicker than that of a normal artery, the blood vessel wall is slightly thicker than that of the abnormal blood vessel, and the blood vessel mainly contains arterial blood, which is consistent with the positioning on the film and can be determined based on the above conditions. However, sometimes due to the mixing of arterial and venous blood and defects in the blood vessel wall itself, it is impossible to determine. In this case, you can use small tweezers or aneurysm clips to clamp the blood vessel and observe for a while. If it is an artery, its distal end will turn into blue venous blood; conversely, if it is a vein, there will be no such change [Figure

(⑷).

5. Ligate the feeding artery After determining the scope of the AVM in the cerebral cortex and the feeding artery, clamp the feeding artery with a silver clip or ligate it with silk thread, but the blood vessels supplying the anterior central gyrus area should be retained [Figure

⑸]. If the main blood supply artery comes from the middle cerebral artery, the sylvian fissure can be carefully divided to expose the middle cerebral artery, and a vascular clamp can be applied to temporarily control blood flow for 6 to 8 minutes, and the branch supplying the hemangioma can be quickly separated and cut off after the silver clamp is applied [Figure

⑹], and then release the small vascular clamp. In short, the main blood supply artery should be ligated as much as possible, and the closer to the hemangioma, the better. At this time, the hemangioma should be seen to become smaller and the blood vessels should shrink. If it does not shrink, it should be considered that there are still main blood supply arteries deep inside, which should be carefully exposed and treated during separation.

6. Separate the hemangioma and electrocoagulate and incise the cortex 3 to 4 mm deep around the hemangioma (the artery with silver clips should be cut off) [Figure

⑺]. Use a brain pressure plate (for deep parts, use a brain pressure plate with light or a cold light source) and a suction device to carefully separate and suction under direct vision, but do not dig blindly to avoid causing heavy bleeding. When encountering larger blood vessels, an aneurysm needle and suture are often used to perform double ligation and then cut off. You can also place silver clips on both sides and then perform electrocoagulation and cutting in the middle [Figure ⑻⑼], but the silver clip must be longer than the diameter of the blood vessel. If there is no large silver clip, a cerebral aneurysm clip can be used. Then gradually separate and flip the malformation, find the main deep blood supply vessels, ligate them firmly and then cut them off, and the brain arteriovenous malformation can be removed [Figure ⑽].

7. Hemostasis of the tumor cavity After the hemangioma is removed, the active bleeding points are stopped with bipolar electrocoagulation or silver clips [Figure ⑾]. Then put a ball of wet brain cotton with a thread in it and use a suction device to make the brain cotton adhere to the wall of the tumor cavity [Figure ⑿]. After a few minutes, carefully and slowly lift up the brain cotton and use bipolar electrocoagulation patiently and meticulously to stop the bleeding. Repeat this treatment and the bleeding will stop. Before closing the skull, fill the tumor cavity with saline and observe again for bleeding; if there is bleeding, continue treatment until the saline in the tumor cavity remains clear and there is no bleeding after removing the antihypertensive drug or compressing the jugular vein.

8. Close the skull

The dura mater is tightly sutured and the dura mater at the edge of the skull window is suspended and sutured. If the dura mater inside the skull window is too loose, a dura mater suspension line can be made. A small hole is drilled from the corresponding part of the skull flap, and the suspension line is led to the outside of the skull and sutured and ligated with the periosteum to eliminate the extradural space as much as possible and reduce the chance of postoperative hematoma formation. A drainage tube is placed under the dura mater and outside the dura mater, and another incision is made to drain the blood out.