Direct carotid cavernous fistula

Introduction of direct carotid cavernous fistula Direct carotid cavernous sinus fistula is more common in trauma, and a few direct carotid cavernous sinus fistulas are spontaneous, mostly due to aneurysm rupture of the cavernous sinus segment of the internal carotid artery, which is indistinguishable from traumatic angiography. . Various causes of internal carotid artery trunk or branch damage, the formation of internal carotid artery and cavernous sinus hypertension, high-flow fistula, and a series of complex clinical manifestations. basic knowledge The proportion of illness: the incidence rate is about 0.001% - 0.003% Susceptible people: no specific population Mode of infection: non-infectious Complications: nosebleeds, shock

Direct carotid cavernous fistula

(1) Causes of the disease

Excluding the injury is the main cause of the disease, the cause of spontaneous carotid cavernous fistula is:

1. Arterial wall abnormalities: muscle fiber dysplasia and Ehlers-Danlos syndrome or elastin pseudo-xanthoma are prone to spontaneous carotid cavernous fistula. In patients with Ehlers-Danlos syndrome, collagen loss causes arterial tortuosity and increased vascular fragility, often causing difficulties in the diagnosis and treatment of the transarterial route. Osteogenesis imperfecta also leads to an increase in vascular fragility, leading to the development of spontaneous carotid cavernous fistula.

2. Inflammation: Cases of spontaneous carotid cavernous fistula caused by syphilis and fungal arteritis are also reported in the literature.

(two) pathogenesis

The main pathogenesis of carotid cavernous fistula is as follows:

1. Stealing blood: The internal carotid artery blood flows directly into the cavernous sinus through the fistula. The blood flow velocity and blood flow of the internal carotid artery are significantly increased, and it is positively correlated with the size of the fistula. A large amount of blood flows into the cavernous sinus, causing insufficient blood supply to the distal end of the internal carotid artery, resulting in cerebral ischemia and insufficient intraocular arterial infusion; the higher the blood flow of the fistula, the greater the amount of blood stealing, the more urgent the course of the disease, and the more severe the symptoms. When the mouth is small, the amount of stealing blood is small, and the Willis cerebral artery ring is in good traffic, the course of the disease is slow and the symptoms are mild or not obvious.

2. Drainage vein dilation and congestion: The cavernous sinus has extensive traffic with the surrounding veins. A large amount of carotid blood directly enters the cavernous sinus, causing high expansion, arterialization and congestion of these veins, and different symptoms due to different venous drainage. The most common way of drainage is to flow into the eyelids through the supraorbital vein, causing pulsating exophthalmos, periorbital venous engorgement, fundus venous congestion, optic disc edema, conjunctival hyperemia, extraocular muscle insufficiency paralysis, etc. Second, when blood When the flow is backward through the inferior sinus, transverse sinus and sigmoid sinus, the eye symptoms are mild and the intracranial murmur can be obvious; when the blood flows upward through the sphenoid sinus into the lateral fissure vein, cortical vein and superior sagittal sinus, Intracranial venous dilatation and increased intracranial pressure or even subarachnoid hemorrhage; blood flow down the skull base to the sulcus, can cause nasopharynx vein dilatation, leading to nosebleeds; in addition, if the blood flow to the inside Drainage can also cause contralateral symptoms through the intersponge sinus.

3. Bleeding: carotid cavernous fistula with dural vascular malformation or excessive dilatation of venous rupture caused by intracranial hemorrhage; continuous retinal vein rupture caused by retinal vein rupture affects vision; nasal and nasopharynx venous dilatation causes nasal bleeding.

Direct carotid cavernous fistula prevention

Prevention of trauma; in addition to the necessary life treatment after trauma, the possibility of internal carotid cavernous fistula should be considered for timely treatment. Do not drink alcoholic beverages for a long time, quit alcohol and tobacco hobbies, do not overeat pickles, sour, spicy and irritating foods, and banned mildew foods. It is more important for people with chronic pharyngitis to develop good food hygiene habits, such as Less than enough, eat more fresh fruits, vegetables and so on.

Direct carotid cavernous fistula complications Complications, episodes of hemorrhage

Patients may have visual impairment, decreased visual acuity, or even blindness. Nasal bleeding may occur after nasopharynx dilatation. The amount of bleeding is often considerable, and may even cause hemorrhagic shock.

Direct carotid cavernous fistula symptoms Common symptoms Conjunctival hyperemia and pulse consistent... Continuous intracranial murmur eyeballs irritability, restless nosebleeds

1. Headache: more common in the early stage, the pain is located in the eyelid area, and the headache will gradually decrease as the disease progresses.

2. Intracranial murmur: almost every case, murmurs such as machine roaring continuous, especially at night and quiet, often make the patient unbearable, irritability, severely affect rest and sleep, auscultation in the affected side of the eyelid, On the forehead, the external ear mastoid, the ankle, or even the entire head, hear a rhythmic murmur consistent with the heart rate; pressing the common carotid artery on the affected side, the noise is reduced or disappeared, and the compression of the contralateral common carotid artery does not disappear or even louder. .

3. Pulsating eye: The eyeball of the affected side protrudes forward and has an eyeball that is consistent with the pulse. The eyeball is caused by congestion and edema of the tissue inside the eye. Touching the eyeball can feel the pulsation of the eyeball and the vibration of the blood flowing. sense.

4. Conjunctival hyperemia and edema: In the affected eyelid, intraocular fistula, conjunctiva, retina and other parts of the venous engorgement congestion, edema, severe conjunctiva over the eyelids, eyelid closure difficulties and exposed keratitis.

5. Eye movement disorders: Insufficient palsy in the affected side of the eye can be accompanied by diplopia, and common paralysis is common.

Direct carotid cavernous fistula examination

1. Cerebral angiography Cerebral angiography mainly understands the location and size of the direct carotid cavernous sinus fistula, whether there is a pseudoaneurysm, sinus varicose or not, and the form of drainage vein includes cortical vein drainage and collateral blood supply. The condition of the arteries, and whether or not a dissection aneurysm is combined.

Comprehensive cerebral angiography should include bilateral common carotid angiography, selective angiography of the affected internal carotid artery and external carotid artery, compression of the internal carotid artery angiography of the affected common carotid artery, and compression of the vertebral angiography of the affected side. The common carotid artery angiography can exclude the presence of a laminated aneurysm, atherosclerotic stenosis, muscle fiber dysplasia or other arterial vascular disease. Selective angiography of the affected internal carotid artery can show the fistula and drainage vein. Selective angiography of the external carotid artery can be used to understand whether the external carotid artery system is also involved in blood supply. The main carotid artery angiography is mainly to know whether there is carotid cavernous fistula or a dissection aneurysm or pseudoaneurysm. The contralateral carotid artery angiography or vertebral angiography was performed on the affected common carotid artery to observe the blood supply of the two arteries through the collaterals of the Willis ring.

In the presence of direct carotid cavernous sinus fistula, the angiographic morphology of the cavernous sinus varies greatly. The cavernous sinus can be expanded in sinus shape, and can also be tubularly connected directly to the dura mater and venous venous (Fig. 1 ), some appear as pseudoaneurysms, filling the entire cavernous sinus space (Figure 2). The flow rate and flow rate of the direct carotid cavernous fistula are large. When the cerebral angiography is performed, the cavernous sinus is often developed rapidly to make the judgment of the position of the fistula difficult. The following measures can help display and determine the position of the fistula:

(1) Insert the common contrast tube into the internal carotid artery of the affected side, press the common carotid artery proximal to the catheter tip, and then inject the contrast agent at a rate of 1 ml/s to make the internal carotid artery and fistula at the distal end of the catheter. With slow development, the exact position of the fistula can be easily observed.

(2) Insert the internal carotid artery with a double-lumen catheter with a balloon, fill the balloon, and then inject the contrast agent at the aforementioned speed, and clearly show the position of the fistula.

(3) Huber method: The common carotid artery was compressed on the affected side, and vertebral artery angiography was performed. After the contrast agent passed, the traffic artery was retrogradely displayed to show the position of the fistula (Fig. 3).

Based on foreign data, the mouth of the mouth is about 40% in the post-up section (paragraph 5), while the front and the front section (paragraphs 2 and 1) only account for 6%. Therefore, Parkinsons mouth is mostly in the cavernous sinus. The statement of the anterior portion of the internal carotid artery is not very accurate.

The size and position of the fistula are very important in the development of the treatment plan. Most of the direct carotid cavernous fistula can successfully occlude the fistula with a balloon. When the balloon can not enter the fistula, the guide microcatheter can be used to enter the sponge through the fistula. Inside the sinus, a micro-coil is placed to fill the cavernous sinus, and some of the fistulas are small. The slow-flowing carotid cavernous fistula can be cured by the common carotid artery compression. If the fistula is too large or the internal carotid artery is broken, the internal carotid artery should be occluded. .

Abnormal expansion of pseudoaneurysm or cavernous sinus can lead to fatal nosebleeds and intracranial hemorrhage, which should be actively treated. The presence of dissecting aneurysms often affects the treatment of carotid cavernous fistula. If the contralateral side has a dissection aneurysm, In the treatment, the internal carotid artery of the affected side cannot be occluded, and when the dissecting aneurysm of the cavernous sinus of the internal carotid artery involves the vicinity of the fistula, the fistula and the internal carotid artery should be occluded together, and it is necessary to occlude the internal carotid artery. Fully understand the establishment of the side branch cycle.

The drainage form of the vein is closely related to the clinical symptoms. The carotid cavernous fistula of the venous drainage of the eye usually has typical ocular symptoms and signs. The upper and lower sinus drainage is prone to cranial nerve palsy, and the cortical vein drainage is easy. , is prone to intracranial hemorrhage, intracranial hypertension and neurological dysfunction.

2. CT and MRI examination showed enhanced dilated ocular veins on the CT or MRI, prominent eyeballs, thickening of the extraocular muscles, swelling of the eyelids, conjunctival edema, increased density or signal of the parasagittal structure, thickening of the cortex Drainage veins and accompanying cerebral edema and traumatic changes such as skull and skull base fractures, brain damage and intracranial hematoma.

3. Transcranial Doppler ultrasound can be used to understand the hemodynamic parameters of carotid cavernous fistula in real time:

(1) Determine the flow velocity of the internal carotid artery of the affected side, including the systolic blood flow velocity Va, the diastolic blood flow velocity Vd and the pulsation index PI. Generally, the blood flow velocity of the direct sputum increases, especially the diastolic flow rate increases. Obviously, it can reach more than 200cm/s; at the same time, the pulsation index decreases below 0.5, and the indirect sputum blood flow velocity and resistance index can be normal or not obvious.

(2) The abnormal spectrum of periorbital vein can be diagnosed by eyelid to assist in the diagnosis of carotid cavernous sinus fistula. The ocular vein and periorbital vein are the most common drainage veins of carotid cavernous sinus. High flow velocity of the supraorbital vein can be found. Arterial blood flow signs, blood flow velocity is almost 1 times higher than the normal side, while the pulsation index is reduced by about half, and return to normal when the treatment is effective.

(3) Detecting intracranial blood flow through the sputum window, can understand the blood stealing situation, and find that the average blood flow velocity of the middle cerebral artery, the anterior cerebral artery and the contralateral anterior cerebral artery increases, and the ipsilateral anterior cerebral artery blood flow direction Reversal, the anterior and posterior communicating artery is open.

(4) Indicating the direction of blood flow. In addition to detecting the blood flow velocity, TCD can also indicate the change of blood flow direction, so it can be used to judge the collateral circulation and the direction of blood flow of the drainage vein. TCD detection is helpful for carotid sponge. Early diagnosis of sinus sputum, selection of treatment options and evaluation of efficacy.

4. Single photon emission computed tomography (SPECT) is a non-invasive method for cerebral perfusion and brain metabolism. The radionuclide such as 99mTc HMPAO is used to detect the amount of cerebral perfusion before and after intravascular treatment of carotid cavernous sinus. For Matas test, it can reflect the collateral circulation. If the radionuclide of the anterior cerebral artery and middle cerebral artery is less than 15%, the occlusion carotid artery will not produce neurological deficit. Therefore, SPECT is the carotid cavernous sinus. The diagnosis and treatment of sputum has a certain guiding role.

Diagnosis and diagnosis of direct carotid cavernous fistula

diagnosis

Pulsating exophthalmos, intracranial murmur, conjunctival hyperemia and edema, nasal bleeding and other clinical manifestations combined with a history of head trauma, diagnosis of this disease is not difficult, skull CT and MRI showed ocular protrusion and intraocular venous or intracranial drainage vein Thickening and accompanying brain tissue edema, TCD and SPECT have the above changes are helpful for diagnosis, and cerebral angiography is the most important means of diagnosis. Both internal carotid artery and vertebral artery angiography must be performed routinely. External angiography, in order to facilitate a clear diagnosis of carotid cavernous fistula blood supply and drainage of the vein.

Differential diagnosis

1. Exophthalmia, hyperthyroidism, intraorbital and posterior orbital tumors or pseudotumors, no pulsating exophthalmos and vascular murmurs, can be identified.

2. Intraorbital vascular lesions, such as cavernous hemangioma, aneurysm, arteriovenous malformation, etc., the identification is more difficult, especially the identification of direct sputum with less flow is more difficult, relying on cerebral angiography.

3. Cavernous sinus thrombophlebitis or thrombosis, the symptoms are very similar to carotid cavernous fistula, but there is no eyeball pulsation and vascular murmur.

4. Wall defect, which may be congenital, traumatic or neoplastic. When the dome is defected, the brain tissue bulges to the defect, causing a prominent eye, and may cause eyeball pulsation due to brain pulsation to the eyeball, but generally Avascular murmur can be identified.

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