Brain hydatidectomy

Central nervous system echinococcosis is a parasitic disease caused by echinococcus granulosus, multi-chamber or echinococcus maltilocularis or alveolaris larvae (echinococcosis). The disease is prevalent in animal husbandry areas in the northwest, northeast and southwestern provinces of China, and is also popular in other countries such as Turkey and other livestock countries. The echinococcosis involving the central nervous system accounts for only 2% to 3% of all echinococcosis, of which echinococcosis (cystic echinococcosis) accounts for an absolute majority, accounting for 92.68%, while others are multi-room thorns. Bulbs (vesicular echinococcosis). According to statistics, about 47.76 percent of central nervous system cystic echinococcosis is located in the brain, and 25.23% is located in the spine and spinal canal.

Intracranial cystic hydatid is mainly distributed in the middle cerebral artery supply area, followed by parietal lobe, frontal lobe, apical lobe, temporal lobe, frontal lobe, occipital lobe and frontal lobe. Other parts such as eyelid, cerebellum and ventricle The inner, thalamus, pons, saddle inside and outside and skull base have been reported. The hydatid is located in the white matter, most of which are single capsules, accounting for 78.57%, and polycystices accounting for 21.42%. The diameter is 3~16cm, the inner capsule wall is thin, contains the germinal layer, the cystic fluid is clear and colorless, and contains numerous nodules; the outer capsule is thicker and looks like powdery skin. The CT scan has a round, low-density shadow with sharp edges and no edema around it. The density of the cyst fluid is similar to that of the cerebrospinal fluid. Usually, the contrast agent is not enhanced, but sometimes the envelope can show ring enhancement, and there are very few capsules and capsules that can be calcified. MRI examination showed that both the T1 and T2 weighted images of the hydatid cyst wall were low-signal annular images, and the T2-weighted images showed better performance on the hydatid cyst wall than T1.

Treating diseases: echinococcosis

Indication

Brain hydatidectomy is suitable for single cystic worms and polycystic worms.

Contraindications

Multiple echinococcosis or post-operative dissemination of the worm, accompanied by liver and pulmonary hydatidosis, the patient is generally in poor condition.

Preoperative preparation

1. There must be a correct positioning diagnosis before surgery. The relationship between the location of the lesion and the surrounding structure should be analyzed before surgery in order to select the appropriate surgical approach, to obtain the best exposure, avoid the important structure of the skull as much as possible, increase the safety of the operation and strive for good Effect.

2. Skin preparation, wash the head with soap and water 1 day before the operation, shave the hair on the morning of the operation. You can also shave your head on the eve of surgery.

3. Fasting the morning of surgery.

4. Give phenobarbital 0.1g orally before surgery to ensure a quiet rest. One hour before the operation, 0.1 g of phenobarbital, 0.4 mg of atropine or 0.3 mg of scopolamine were intramuscularly injected.

Surgical procedure

1. According to the position of the lesion suggested by preoperative CT or MRI, make a skin flap larger than the diameter of the worm. Children's skulls are relatively thin, and some patients' capsular sacs are close to the dura mater. When drilling the skull and opening the bone flap, care should be taken to prevent tearing of the dura mater and the hydatid cyst wall and contaminating the surgical field.

2. If the hydatid is smaller and farther away from the functional area, the cortical cortex is cut in the corresponding part of the hydatid, and the cortical incision is separated after the brain plate is separated. The appearance is a powdery-like capsule which is the wall of the hydatid, along its circumference. Gently separate into the deep part, and can be completely removed without collapse.

3. When the hydatid is larger or partially close to the cortical surface, the adhesion and blood vessels are treated by bipolar electrocoagulation along the exposed junction of the hydatid and the cortex, and then separated between the hydatid cyst and the brain tissue. If the hydatid is located in a deeper part, the incision of electrocoagulation and incision of the cerebral cortex should be large enough to avoid excessive contusion of the brain parenchyma when the hydatid is isolated. When separated to reveal the diameter of the worm, it can no longer be separated into the deep. At this point, the patient's head position is lowered, so that the hydatid cyst is located at a lower part, and a physiological saline-filled irrigator is used to inject a little force between the hydatid sac and the surrounding brain tissue. Because the hydatid cyst and the surrounding gelatinized brain tissue have neither blood vessel communication nor close adhesion, the hydatid cyst is gradually separated from the cyst bed until it is released from the deep brain by the action of water and the gravity of the hydatid cyst. This is called the "hydraulic floatation separation method", also known as the Dowing's technique, which was first adopted by Arana-Inignez in 1955. This method is also used in some hospitals in China. Practice has proved that this method is concise and practical, relatively safe, and most single cystic worms and polycystic worms can be completely removed by this technique.

4. Puncture drainage and hydatid cyst removal is suitable for the shallow part of the worm. After the hydatid sac is exposed, the surrounding brain tissue is properly protected by cotton sheets. The needle is pierced at the highest point of the capsule, and the sac is extracted with an empty needle. The capsule fluid was repeatedly injected into the capsule with an appropriate amount of 3% hydrogen peroxide dissolved hydrogen solution or 3% hypertonic saline, and left for 10 minutes to kill the residual head section. Then rinse again with normal saline or 3% hypertonic saline. When the extract is not visible, the wall is carefully removed.

5.Negovetic et al. have reported that the brain worms simultaneously invade the skull and meninges. The main surgical points are: first make a bone flap smaller than the diameter of the worm, remove the dura mater and remove the dura mater. Then, the inner wall of the capsule was applied with a 10% formaldehyde solution, and the hypertonic saline repeatedly rinsed the capsule cavity to kill the head section. Then the diseased bone is bitten until the normal skull, the bone window should exceed the diameter of the worm, the diseased dura mater is removed, and the hydatid sac is carefully separated and removed from the surrounding brain tissue. Defective dura mater and skull are properly repaired.

6. The incidence of intracranial multi-atrial hydatidosis (vesicular echinococcosis) is very low. Alinors et al reported that there were only 16 cases of 219 cases of intracranial hydatid, and this type of hydati also advocated full removal. In recent years, Schmid et al reported that the combination of gamma knife and albendazole has a good effect. After MRI follow-up, it was found that the hydatid was significantly reduced after irradiation. The pericapsular edema was heavier. After 3 years, polycystic lesions and edema and neurological symptoms were significantly improved. It is considered that -knife is an alternative treatment for inoperable vesicular worms.

complication

1. After the removal of the giant hydatid, the pressure in the cranial cavity is drastically reduced, and the brain tissue collapses, which may cause tearing of the bridge vein and an intracranial hematoma.

2. The complications reported in the literature were followed by a sharp decline in visual acuity, epilepsy, subdural effusion, deep vein thrombosis and gas cranium.