Interventional neuroradiology has been carried out in China for more than 20 years. At present, in addition to neurosurgeons, there are also radiologists, neurologists and interventionalists who are engaged in this work. Due to the different training experience and clinical philosophy of the physicians in each specialty, there is a lack of experience or differences in training philosophy, such as confusion in the selection of indications, rough and irregular technical operation, and lack of prevention and management of complications, etc. There are many problems in the work. If not corrected and guided in time will make this new technology fall into abuse.
In February 2005, the Endovascular Therapy Group of the Neurosurgery Branch of the Chinese Medical Association invited 24 clinical experts in neuroradiology and cerebrovascular disease from neurosurgery, neurology and interventional radiology across the country to develop a code of practice for diagnostic and therapeutic interventional neuroradiology in Sanya, Hainan, which will be used as an industry standard and legal reference and revised from time to time.
Part 1 Equipment personnel conditions and contrast
Section 1 Interventional neuroradiology catheterization laboratory equipment and personnel
1, digital subtraction angiography equipment conditions
① must have: TV fluoroscopy equipment, path map (ROAD a MAP), C-arm, movable catheter bed
②It is best to have: forward and lateral bi-directional bulb tube, 3D angiographic reconstruction function software, automatic high-pressure injector.
2.Cath lab basic facilities
① should have: sterilization and sterilization conditions, monitoring (nursing) equipment, oxygen, negative pressure suction and other resuscitation facilities, such as anesthesia machines and ancillary devices, monitoring coagulation instruments, emergency drug cart.
② standing drugs: heparin sodium injection, fisetin injection, sodium nitroprusside, urokinase, infant sulforaphane, calcium antagonists, epinephrine, dexamethasone injection, anesthesia and anti-epileptic drugs.
③Protective equipment: lead coat, lead glasses, lead cap, lead scarf, lead skin and lead screen, storage cabinet for catheter materials, arterial infusion pressurized bag (bag) and bagged isotonic saline, catheter shaper (such as steam kettle).
3.Basic staffing
Physician, anesthesiologist, technician, nurse.
4.Single-use materials
Interventional equipment for single-use into the human body
5.Cerebral angiography procedure kit
Section 2 interferential neuroradiography
1.Whole brain angiography
1.1 Indications
①Intracranial and extracranial vascular lesions. Such as hemorrhagic or occlusive cerebrovascular lesions.
②Etiology examination of spontaneous intracerebral hematoma or subarachnoid hemorrhage (SAH).
③Blood-rich tumors of the head and face, preoperative understanding of blood supply status.
④Observation of blood supply of intracranial occupying lesions in relation to adjacent vessels and characterization of certain tumors.
⑤ Review after treatment of head, face and intracranial vascular diseases.
1. 2 Contraindications
①Iodine allergy (to be performed after desensitization treatment, or using contrast agent without iodine).
②Persons with serious bleeding tendency or bleeding disorders.
③Persons with severe cardiac, hepatic or renal insufficiency.
④Those with advanced brain herniation and brainstem failure.
1. 3 Preoperative preparation
①Routine preoperative examination: including blood and urine routine, bleeding and coagulation time, liver and kidney function, electrocardiogram and chest X-ray.
②8h preoperative fasting, special cases, such as emergencies can be appropriately shortened at the discretion of the anesthesiologist.
③Iodine allergy test: 1 ml of the contrast agent to be used for imaging, intravenous push. No allergic signs such as panic, shortness of breath, urticaria and bulbar conjunctival congestion, and blood pressure pulsations below 10-20 mm Hg measured before and after injection are considered negative. If the iodine allergy test is positive and contrast must be performed, hormone therapy should be given 3 d before surgery and non-ionic iodine aqueous contrast agent should be used as much as possible.
④Bilateral inguinal and perineal area skin preparation:A catheter should be left in place for patients with long operation time.
⑤ Intramuscular injection of phenobarbital 30 min before surgery.
⑥If appropriate, calcium antagonists should be given intravenously and continuously 24 h before surgery.
(7) Equipment preparation: 1 angiography bag, 2 pressure bags, 500ml x 4 bags of soft packing isotonic saline, 1 Y-shaped valve, 2 tee connectors, 1 cerebral angiography catheter (5F or 4F, different shape of catheter if the vessel is migrated), 1 catheter sheath (5F, 6F), 1 short guidewire of 30cm and 1 long guidewire of 160cm each. High-pressure syringe and connecting tube, 100-200 ml of contrast medium. Puncture needle (16G or 18G for adults, 18G or 20G for children ).
1. 4 Operation method
1.4.1 Operation steps of transfemoral artery puncture:
① Routinely disinfect the inguinal and perineal areas bilaterally by spreading sheets and exposing both sides of the groin.
② Connect at least 2 sets of intra-arterial continuous drippers (1 of which is connected to the catheter sheath and the other is spare or connected to a Y-valve guidewire). Connect a high-pressure syringe and aspirate the contrast medium. All connections should be free of air bubbles. The contrast tube is flushed with heparin saline.
The puncture site is chosen 1.5-2 cm below the inguinal ligament where the femoral artery pulsation is most evident, and is anesthetized by local infiltration.
④After successful puncture, a vascular sheath was placed with the aid of a short guidewire. Continuous titration is regulated with a drop count of 15 to 30 drops/min.
⑤ Systemic heparinization, control activated partial thromboplastin time (APTT) > 120 s, or activated clotting time (ACT) > 250 s. The method of heparinization can be referred to the following: the first dose of 2/3 mg per kg of body weight is given intravenously, followed by half a dose after 1 h, and then 1/4 amount after 2 h. Additional half of the previous dose is given every 1 h thereafter, and if it is reduced to 10 mg, every 1 h Give 10mg.
(6) Under fluoroscopy, whole brain angiography was performed sequentially, including bilateral internal and external carotid arteries and bilateral vertebral arteries. Bilateral thyrocervical trunk and cribriocervical trunk angiograms should be performed if necessary. In the case of tortuous vessels, a guide wire can be used to assist when the catheter cannot be placed.
(7) In elderly patients, each trunk artery should be contrasted in sections from the bottom up, and if necessary, the aortic arch should be contrasted with a pigtail catheter.
(8) Neutralize sodium heparin with fisetin (1-1.5 mg can counteract 1 mg of sodium heparin) after the end of the angiogram.
1.4.2 Postoperative management:
①Compression and pressure bandaging of the puncture site, bed rest for 24h, keeping the lower limb on the punctured side straight.
②Monitor the dorsalis pedis artery pulsation of the punctured limb for 1 time/0.5h.
③Give antibiotics and hormones appropriately.
2.Spinal angiography
2.1 Indications
①Spinal cord vascular lesions.
②Partial cerebral subarachnoid hemorrhage and negative cerebral angiography.
③To understand the relationship between spinal cord tumor and blood vessels.
④Preoperative embolization of spinal cord vascular rich tumor.
⑤ Review of spinal cord vascular lesions.
2. 2 Contraindications
①If you are allergic to iodine.
②Persons with serious bleeding tendency or bleeding disorders.
③Persons with severe cardiac, hepatic or renal insufficiency.
④Patients with severe hypertension or atherosclerosis.
2. 3 Preoperative preparation
Same as cerebral angiography.
2. 4 Operation method and procedure
Same as cerebral angiography.
2.5 Precautions
①Before the angiogram, lead number or other markers must be affixed under fluoroscopy to clarify the location of the corresponding vertebral body.
②The angiogram must include all spinal arteries, such as bilateral vertebral arteries, thyrocervical trunk, cribriocervical trunk, each intercostal artery, lumbar artery, and internal skeletal artery.
③The routine injection dose for the intercostal and lumbar arteries is 1 ml/s for a total of 2 to 5 ml. If there are lesions with high blood flow, the dose may be increased appropriately.
2. 6 Complications
Same as cerebral angiography. Individual patients may suffer from increased symptoms such as paralysis and sensory impairment, which may be related to catheter stimulation causing arterial spasm and blocked blood flow, thus aggravating spinal cord ischemia. Before imaging, dexamethasone and calcium antagonists are used. The catheter should not be too thick, 4F or 5F is appropriate.
Part 2 Hemorrhagic cerebrovascular disease
Section 1 Intracranial aneurysm
1. 1 Indications
Ruptured aneurysm: If the patient’s general condition can tolerate anesthesia and the technique can achieve the treatment purpose, interposition therapy can be performed; Hunt-Hess grade I-III should be treated actively, and grade IV-V should be treated as appropriate.
(2) Unruptured aneurysm: If the patient’s general condition can tolerate anesthesia and the technique can achieve the treatment purpose, interferential treatment can be performed.
1. 2 Contraindications
①The patient’s general condition cannot tolerate anesthesia.
②The current interventional technology cannot achieve the treatment purpose.
③Patients and/or family members refuse interventional treatment.
④Other conditions that are not suitable for interventional treatment.
1.3 Preoperative preparation
1.3.1 Routine blood and urine tests, bleeding and clotting times, liver and kidney functions, electrocardiogram and other routine tests.
1.3.2 CT examination:The diagnosis of SAH can exclude other concomitant intracranial disorders. Intensive high-resolution thin-layer scan can detect aneurysms >5mm in diameter, and can find out whether there is calcification in the aneurysm wall or whether there is thrombosis in the aneurysm. Spiral CT 3D reconstruction can initially screen for aneurysms.
1.3.3 MRI/MRA (as appropriate): roughly shows the location of aneurysm, shows whether there is thrombosis within the aneurysm, and clearly shows the relationship between the aneurysm and the surrounding brain tissue.
1.3.4 Cerebral angiography:
The timing of angiography should be as early as possible for patients with SAH who are highly suspected of intracranial aneurysm, and patients with Hunt-Hess grade IV-V should be angiographed as appropriate.
②The principle of imaging, when intracranial aneurysm is highly suspected, whole brain angiography should be performed, including bilateral internal carotid arteries and bilateral vertebral arteries. The vertebral arteries should show the bilateral posterior inferior cerebellar arteries. If necessary, external carotid artery and spinal angiography should be added. In case of aneurysm of one internal carotid artery, a cross-circulation test should be performed at the same time, i.e., compression of the affected internal carotid artery and contralateral internal carotid artery and vertebral artery should be performed to observe the compensatory capacity of Willis loop. If necessary, multiple angles of projection or three-dimensional reconstruction should be performed, and those with negative SAH angiograms should be reexamined after 2 weeks.
The reasons for false negative cerebral angiogram are: spasm of the aneurysm-carrying artery, aneurysm too small, thrombus in the aneurysm lumen preventing the entry of the contrast agent, poor equipment condition, no multi-angle angiographic observation, and failure to identify the aneurysm by reading the film.
1.4 Operation method
1.4.1 Intracapsular embolization of aneurysm:
①Embolization materials, 5 a 7F soft tip guiding catheter, guidewire guiding microcatheter (10, 14,18 series), microguiding wire (10,14,18 series) with microcatheter, controlled release spring ring and release system, liquid embolization material and its embolization system.
②Embolization points, general anesthesia and general heparinization as much as possible (except within 4h after SAH). Select 1-2 best working angles according to the imaging results so that both the aneurysm neck and the aneurysm body are clearly shown. Microcatheter shaping is performed according to the location and morphology of the aneurysm. The microcatheter should be operated slowly and smoothly, without jumping forward. The tip of the microcatheter should not be placed against the aneurysm wall. The spring coil should be selected based on the measurement of the aneurysm. The diameter of the first coil should be larger than the aneurysm neck, equal to or slightly larger than the minimum diameter of the aneurysm, and as long as possible so that it can be coiled into a basket shape against the aneurysm wall within the aneurysm. For small aneurysms with recent bleeding, a soft spring coil should be selected whenever possible. The proper placement of the spring coil should be confirmed by imaging to ensure that there is no normal vascular occlusion before uncapping. The spring coil should be filled as densely as possible.
1.4.2 Balloon reshaping protection technique:
①Embolization materials, in addition to the above materials, need to prepare the corresponding size of the protection balloon.
②Embolization points, applicable to wide carotid aneurysm. For liquid embolic agent embolization, the protective balloon must be used. The time of balloon occlusion of the aneurysm-carrying artery should be shortened as much as possible, usually not more than 5 min each time, and the spring-ring embolization should be as dense as possible.
1.4.3 Stent-assisted techniques:
①Embolytic materials, in addition to the above materials, self-expanding stents or balloon-expandable stents of appropriate size need to be prepared. Use protective balloon if necessary.
②Embolization points, applicable to cases of wide carotid aneurysm, shuttle aneurysm, sandwich aneurysm and severe stenosis of the aneurysm-carrying artery near the aneurysm. Anti-platelet aggregation drugs should be given adequately before and after surgery to avoid entanglement of the spring ring with the stent, and displacement and collapse of the stent should be avoided.
1.4.4 Technique of aneurysm-carrying artery occlusion:
①indications and conditions, internal carotid artery and posterior circulation shuttle, wide neck, giant aneurysm; those who are unable or unsuitable for intra-aneurysmal embolization, such as pseudo or entrapped aneurysm; adequate compensation of collateral circulation and negative balloon occlusion test (BOT).
② Clinical signs of negative balloon occlusion test, no neurological disorder, negative reinforcement test (20-30 mm Hg, 20-30 min).
③The imaging sign of adequate compensation of the collateral circulation is good capillary filling on the affected side when the healthy cerebral arteriogram is performed after balloon occlusion; the bilateral venous phase appears at the same time, and the difference between the filling time on the affected side and that on the healthy side is <1.5s.
1.5 Precautions
①Ideal aneurysm embolization needs to achieve dense filling of the sac, and sparing embolization cannot achieve the purpose of preventing aneurysm rebleeding.
②Dense filling of the aneurysm neck using various techniques and skills is required to prevent regrowth of the aneurysm as much as possible.
③Simple filling of pseudoaneurysms and the pseudo part of general aneurysms cannot prevent rebleeding of aneurysms.
④To try to prevent thrombosis during aneurysm embolization, complete systemic anticoagulation and continuous titration of the coaxial system are generally required. For those who cannot be anticoagulated during the acute phase of bleeding, the operation time should be shortened as much as possible and continuous drip of the coaxial system should be ensured.
1. 6 Complications
The following complications are impossible to avoid completely and should be given high priority. Common complications are
1.6.1 Cerebral vasospasm:
①Cause, caused by SAH, stimulation of intravascular catheter and guidewire.
②Treatment, see treatment of cerebral vasospasm.
1.6.2 Thrombosis:
①Cause, no anticoagulation or incomplete anticoagulation, insufficient antiplatelet aggregation treatment before and after using stent, no continuous perfusion of coaxial system.
②Treatment, conventional thrombolysis according to emergency thrombolysis should be performed after complete dense filling of the aneurysm, and super-selective thrombolysis with microcatheters should be used as much as possible. The dose of thrombolytic drug should be as small as possible and should be based on the standard of vascular patency on imaging.
1.6.3 Aneurysm rupture:
① Cause, natural rupture of aneurysm. The manipulation of catheter and guidewire induces rupture of aneurysm, and overfilling of spring coil causes protrusion of aneurysm.
②Treatment, maintain sedation. Neutralize heparin and give hemostatic drugs. Lower the blood pressure in the body circulation to reduce bleeding from the rupture. Fill the aneurysm rapidly and densely. Reduce the injection of contrast medium in the aneurysm-carrying artery. Decrease intracranial pressure. Routine CT scan after embolization.
1.6.4 Cerebral ischemia :
①Cause, vasospasm and other vascular lesions, mechanical compression after embolization of large aneurysms, inadequate collateral circulation after occlusion of the aneurysm-carrying artery, and prolonged surgical operation.
②Treatment, for those with mechanical compression, give pressure-raising, anticoagulation and volume expansion treatment; for those with insufficient blood circulation compensation, if pressure-raising, anticoagulation and volume expansion treatment are ineffective, emergency bypass surgery is feasible.
1.6.5 Treatment of spring coil fracture and displacement:
① Once it occurs, pull the spring coil out of the vessel as far as possible.
②If it cannot be removed, unscrew the spring coil as much as possible and pull it into the descending aorta.
③After the failure of removal, it can be given to raise the pressure, anticoagulation and expansion treatment.
④If removal fails, a stent can also be used to attach the free portion of the spring coil to the arterial wall.
1.6.6 Others.
Section 2 intracranial arteriovenous malformation
1.Indications
The purpose of interventional treatment :
①Cure by embolization alone.
②To create conditions for surgical resection and stereotactic radiotherapy.
③Remove risk factors and reduce the possibility of bleeding during lesion occlusion.
④Current treatments are unable to cure the lesion anatomically and can be used to relieve symptoms and reduce the risk of bleeding through embolization.
Currently, embolization is available for all intracranial arteriovenous malformations that can be put in place by microcatheters, including:
(i) inoperable intracranial arteriovenous malformations in which the patient has significant clinical symptoms.
(ii) Deep intracranial arteriovenous malformations, functional areas and giant cerebral arteriovenous malformations.
③There are aneurysms and giant arteriovenous fistulae.
The following conditions should be treated actively and early:
①Newborns or children with heart failure due to high-flow intracranial arteriovenous fistula.
②Vessel rupture requiring emergency embolization during angiography.
③The blood supply artery with pseudoaneurysm or blood flow-related aneurysm, and the aneurysm gradually increases in size.
④The contrast shows narrowing of the draining vein, stagnation and aneurysmal dilatation of the vein.
⑤ There is obvious aneurysm in the malformation group.
2.Contraindication
(1) Those who cannot tolerate anesthesia in their general condition.
②The current interventional technology cannot achieve the treatment purpose. ③Patients and family members refuse interventional treatment.
3. Preoperative preparation
3.1 Preoperative evaluation and determination of treatment plan
Take a careful medical history and physical examination, carefully assess the correlation between the lesion and symptoms and signs, and determine the purpose, target and extent of embolization.
Preoperative examination includes:
①Blood and urine routine, bleeding and clotting time, liver and kidney function, electrocardiogram, etc.
CT examination has a 50% positive detection rate; it has reference significance for the localization of vascular malformation; it shows high-density dotted or worm-like intensification shadow, and may also see coarse drainage veins; it can show calcification foci, the degree of bleeding and the impact on brain tissue structure; it can detect other concomitant intracranial diseases.
(iii) MRI, MRA, MRI (recommended), with special “flow-space effect”, the detection rate can reach 100%. It can roughly show the structure of the malformation mass and determine the relationship between the focal area and the functional area.
④TCD detection (recommended), high systolic and diastolic flow spectrum; disorganization, widening and unclear edges of the spectral waveform; reverse flow with contralateral or affected side low flow velocity spectrum; abnormal compression neck test.
⑤ Angiography is a confirmatory test, and the contents to be understood include:
a. Whether the lesion site is consistent with the patient’s clinical symptoms and signs.
b. The number of branches of the blood supply artery, whether it is the main blood supply artery, and whether it is accompanied by flow-related aneurysm.
c. Classification of intracranial arteriovenous malformations: terminal blood supply, penetrating blood supply or high-flow arteriovenous fistula; whether the structure of the malformed mass is infantile, diffuse, fistula or mixed; whether the malformed mass is accompanied by aneurysm.
d. The number, route, depth and superficiality of the draining veins, and whether the draining veins are accompanied by abnormalities, such as stenosis, dilatation and arterialized venous aneurysm.
e. The duration of arteriovenous circulation. f: Whether the external carotid artery is involved in blood supply.
3. 2 Preoperative medication
If the lesion is located in the functional cortical area to epileptogenesis, it is recommended to give antiepileptic treatment.
4. Operation method
4. 1 Embolization materials
5-8F guiding catheter, blood flow guiding microcatheter, guiding effect guiding microcatheter, microguiding effect with microcatheter; catheter shaper (such as steam kettle, electric hairdryer, etc.); liquid embolic agent and its developing material (super liquefied iodine oil, iodophenyl ester ,tantalum powder, etc.); detachable balloon and delivery system; controlled detachable spring ring and detachable system free spring ring, etc.
4. 2 Embolization points
4. 2. 1 Intraoperative management:
① It is recommended to use general anesthesia with tracheal intubation, especially for patients and children who cannot cooperate; neuroleptic analgesic anesthesia can also be chosen. Routine ECG, blood pressure and oxygen saturation monitoring should be performed.
②The transfemoral route is generally chosen. In case of tortuous vessels, other routes (such as carotid, axillary and radial arteries) can be chosen.
③To prevent bleeding due to hemodynamic changes after embolization, controlled blood pressure should be lowered by l0% to 20% before embolization. For huge intracranial arteriovenous malformations with more than 30% embolization at one time or poorly draining veins, especially controlled blood pressure should be lowered.
4. 2. 2 Microcatheter technique: Depending on the vascular architecture, either floating catheter or guidewire guiding catheter can be chosen.
① Floating catheter, choose the appropriate blood flow guiding microcatheter. For those who have tortuous blood supply arteries or small blood flow, the catheter is difficult to be in place, the soft guidewire can be used to assist and the following measures: rapid pushing of isotonic saline in the guiding catheter; compression of the contralateral carotid artery to increase blood flow when the internal carotid artery is supplied with blood; reshaping of the head end of the microcatheter to change the original curvature; pushing of isotonic saline in the microcatheter to adjust the position of the head end of the microcatheter.
②When using a guidewire to guide the microcatheter, prevent the guidewire or catheter from puncturing the vessel. The microcatheter should enter the malformed mass to embolize as much as possible. After the microcatheter is in place, repeated multi-angle superselective angiography should be performed to avoid embolization of normal vessels as much as possible.
4. 2. 3 Embolization procedure:
①Choose the concentration and speed of glue injection according to the structure of the hyper-selected vascular malformation mass and blood flow velocity.
②Embolization should be performed under pathogram, subtraction or high-definition fluoroscopy, and the speed and duration of glue injection should be adjusted intraoperatively according to the travel and coalescence of the embolic material.
③Avoid embolization of the draining vein as much as possible until the vascular malformation mass is completely occluded.
④ Depending on the concentration of the type of embolic agent and the structure of the donor artery, determine the length of embolic agent return in the donor artery, the time and speed of extraction, and whether to leave the catheter in place.
⑤ High-flow arteriovenous fistulas can be embolized in combination with balloons and spring coils. The ideal embolization imaging outcome is complete and permanent occlusion of the malformed mass with no occlusion of the normal arterioles. There is no significance to the permanent occlusion of the vascular malformation if the blood supply artery is embolized alone.
5.Cautions
①Patients with preoperative history of epilepsy should continue to take antiepileptic drugs postoperatively.
②For intraoperative occlusion of large arteriovenous fistulas, hyperemic lesions and giant arteriovenous malformations with more than 30% embolization at one time, controlled blood pressure should be lowered for 24-48h.
③After the microcatheter is in place, when performing super-selective imaging, multi-angle observation should be repeated to confirm that there is no normal blood supply artery in the embolized area before embolization.
6.Remarks
6.1 Determination of curative effect
①Cure: the lesion disappears and the neurological symptoms return to normal.
②Improved: most of the lesions disappear, and the original symptoms are significantly reduced; the size of the deformity group is reduced to the extent that it can be treated by surgery or stereotactic radiation therapy.
③unhealed:the symptoms cannot be embolized or worsen after embolization.
6.2 Typing
6.2.1 Classification by site
6.2.2 Classification by size (Y asargil, 1988):
①Cryptic type.
②Concealed type.
③Micro.
④Small. Diameter 1-1/2 cm.
⑤ Medium-sized. 2-4 cm in diameter.
⑥Large type, diameter 4-6 cm.
⑦ Giant, diameter >6 cm.
6.2.3 Classification by angiography:
(i) Plexiform:visible only in the arterial stage; visible in all stages; visible only in the venous stage.
②Mixed plexiform and fistulous: plexiform > fistulous; plexiform = fistulous; plexiform < fistulous.
(iii) Fistulous: arteriovenous fistula with very small plexiform
intracranial arteriovenous malformation; simple and direct arteriovenous fistula, visible only in the arterial phase.
6.3 Hemodynamics
①Low inflow pressure in arteries.
(ii) High venous outflow pressure.
③Abnormal blood distribution.
④”Blood theft” phenomenon.
⑤Insufficient normal cerebral perfusion.
(6) Impaired autoregulation function.
6.4 Clinical manifestations
Intracranial hemorrhage, epilepsy, headache, neurological deficits, intracranial murmur, mental retardation, protruding eyes, optic disc edema and damage to the cardiovascular system.
Section 3 Dural arteriovenous fistula
1.Indications
The purpose of interventional treatment:
① Interventional treatment alone can cure the disease.
② Relieve the symptoms.
③Embolization combined with surgery and/or stereotactic radiotherapy.
Active treatment is required in the following cases:
①History of cerebral hemorrhage.
(ii) Intolerable intracranial murmur.
③Progressive neurological dysfunction.
④ local compression symptoms.
⑤ Increased intracranial pressure.
⑥There is a potential risk of intracranial hemorrhage and neurological dysfunction.
Indications for emergency management:
(i) There is cortical venous drainage with bleeding.
②with multiple venous and venous sinus thrombosis or marked dilatation.
③Cavernous sinus, middle cranial fossa, and anterior cranial fossa lesions that cause deterioration of visual acuity.
④Increased intracranial pressure or progressive neurological dysfunction.
2.Contraindication
①The general condition cannot tolerate anesthesia.
②The current interventional technology cannot achieve the treatment purpose.
③Patients and family members refuse interventional treatment.
3.Pre-operative preparation
3.1 Fully understand the relationship between symptoms, signs and lesions
①Consciousness status. Intracranial pressure and degree of hydrocephalus. Check the ocular signs for lesions in the spongy sinus area.
3.2 Preoperative examination
3.2.1 CT and/or CTA: ①Discovery of cerebral white matter edema, hydrocephalus and abnormal thickened vascular shadow. Suggest abnormal dilatation of venous sinus. Find intracranial hemorrhage. Suggest concomitant abnormalities, such as bone abnormalities.
3.2.2 M R I and/or M RA: Shows the same as CT and/or CTA, but with higher resolution.
3.2.3 Angiography: Comprehensive cerebral angiography (including external carotid angiography) is a confirmatory test.
The examination includes:
①The location of the fistula.
(2) The supply artery, whether it is a combined internal and external carotid artery; whether the supply originates bilaterally or unilaterally. Dangerous anastomosis:
a. The middle meningeal artery anastomoses with the ophthalmic artery in the supraorbital fissure;
b, anastomosis of the intracranial artery with the cavernous sinus segment of the internal carotid artery through the middle meningeal artery, the cavernous sinus branch of the collateral meningeal artery and the foramen ovale artery;
c, anastomosis between the ascending pharyngeal artery and the vertebrobasilar artery;
d, anastomosis between the C1 and C2 segments of the occipital artery and the vertebral artery.
③. Condition of the draining veins and venous sinuses, dilatation; dysplasia; stenosis, atresia or thrombosis.
④The entire cerebral circulation time.
⑤ Any concomitant anomalies, such as cerebral arteriovenous malformations; maxillofacial arteriovenous malformations; intradural and extradural aneurysms; multiple arteriovenous fistulas; Rendou-Osler-Weber syndrome; cranial arteriovenous malformations, etc.