Carotid-cavernous anastomosis is a pathological connection of the cavernous sinus and carotid artery inside the cranial cavity, which most often occurs due to craniocerebral injuries. Less commonly, this pathology develops due to an existing infection and vascular anomaly. Blood in the affected vein is converted into arterial, venous pressure increases, and there is a violation of the drainage of the vein in volume and direction. Let's look in more detail at what symptoms are accompanied by a carotid-cavernous anastomosis, what are the causes of this pathology, as well as diagnostic and treatment methods.
general information
Normally, oxygen-rich arterial blood should flow in the internal carotid artery, supplying the bulk of our brain with nutrients and oxygen. The so-called cavernous sinus is considered to be an extension of the intracranial vein, the blood through which flows directly from the brain, its membranes, which is extremely important. The walls on the internal carotid artery, directly in the cavernous part, are fragile and thin, so it is quite easy to damage them.
Ailment mechanism
For the above reason, during damage, arterial blood under the influence of high pressure begins to rush into the cavernous sinus, mixing with the venous, which provokes an increase in pressure in the cavernous sinus and impaired drainage function of the veins. As a result of all this, venous blood begins to stagnate in the brain and in the orbits. The sinus begins to noticeably increase in size and expand, squeezing the cranial nerves passing through it: the orbital, oculomotor, maxillary, block and abduction.
Direct anastomosis
These anastomoses are diagnosed in 80% of cases, while representing a direct message between the cavernous sinus and carotid artery. This variety of carotid-cavernous anastomosis can arise for the following reasons:
- Injury in 75% of cases. The fact is that a fracture of the base of the skull can provoke a rupture of the carotid internal artery in the intracranial area with a dramatic and sudden development of signs and symptoms.
- A sharp rupture of an intracavernous aneurysm or atherosclerotic plaque. At risk are women suffering from postmenopausal hypertension. With spontaneous anastomosis, the blood flow velocity will be lower than with a traumatic one, and the symptoms will be less pronounced.
Signs of a violation can manifest themselves in a few days or weeks after injuring the skull in the form of noise in the head, conjunctival chemosis, as well as severe pulsation. As a rule, these signs manifest themselves on the side of the anastomosis, but can also be bilateral.
In almost all cases, such an anastomosis does not threaten a person's life, but the eye can be severely affected.
Indirect anastomosis
In the case of indirect carotid-cavernous anastomosis, the intracavernous portion of the carotid internal artery is intact. Blood from an artery does not penetrate into the cavernous sinus directly, but through the meningeal branches of the internal and external carotid arteries. Due to the weakened blood flow, clinical symptoms are less pronounced than in the case of direct anastomosis. It is for this reason that the patient's condition may be judged incorrectly or not noticed at all.
The following types of indirect anastomosis are divided:
- Between the meningeal branches of the carotid internal artery, as well as the cavernous sinus.
- Between the meningeal branches of the carotid external artery, as well as the cavernous sinus.
- Between the meningeal branches of two arteries, as well as the cavernous sinus.
As for the causes of indirect anastomosis, they can consist in a congenital malformation, during which symptoms associated with vascular intracranial thrombosis occur. In addition, the cause may be a spontaneous rupture that occurred with a minor injury or with normal stress. Most often this is observed in hypertensive patients.
During the development of this type of anastomosis, one or both eyes gradually blush due to overflow of conjunctival vessels with blood.
Symptom is an increased pulsation of the eyeballs, which is better seen during applanation tonometry. A small exophthalmos in combination with a slight noise, dilated episcleral conjunctival vessels are also signs of the development of an indirect carotid-cavernous anastomosis.
Signs and Symptoms
How can this pathology be recognized in humans? First of all, it is necessary to pay attention to certain signs. Symptoms of a carotid-cavernous anastomosis are as follows:
- Sensation of noise inside one’s head. This noise is synchronous with the pulse on the radial artery.
- Dizziness.
- Headache, which is most pronounced in the fronto-orbital zone.
- Ripple of the eye that occurs during a stroke of a blood wave due to the carotid internal artery to the sinus and back into the veins of the eye.
- Blueness and swelling of the soft tissues around the eye: conjunctiva, subcutaneous fat, skin.
If you have the above signs and symptoms, then this may indicate the presence of such an unpleasant ailment as carotid-cavernous anastomosis (in ICD-10 its code is Q28). Do not ignore them, since the lack of treatment can lead to various kinds of complications.
Development reasons
But what are the causes of the development of carotid-cavernous anastomosis? Most often this occurs due to traumatic brain injuries. The fact is that a strong and sharp blow to the facial region of the skull can provoke the extrusion of the damaged or thinned wall of the carotid internal artery to the sinus, as well as the formation of a connection between these elements, which should normally be absent.
Due to the fact that the blood pressure in the carotid internal artery is greater than the pressure in the cavernous sinus, arterial blood rises under pressure into the sinus, and from there penetrates the central vein of the eye, as well as other orbital veins. These veins are too narrow for blood pressure, which is why the flow of fluid that flows through these veins under pressure creates a wave of noise that the patient feels. In addition, the blood pressure is always much less than in the carotid internal artery, therefore, increased blood pressure from the back pushes the eye, causing its pulsation from the outside.
Carotid-cavernous anastomosis (according to ICD-10 code above) can occur not immediately after injury, but after a few days or even several months. The sooner you seek the help of a doctor, the more chances you will have to maintain health and also reduce the risk of various complications. If there are symptoms of carotid-cavernous anastomosis in the eyes, then a neurologist will help you cure this disease.
Diagnostic Methods
To get rid of this disease, it is necessary to undergo a diagnostic examination. First of all, the specialist should collect complaints and anamnesis of this ailment. For this, he is interested in the patient how long he had the symptoms of the disease, eye pulsation, and also a headache. In addition, the neurologist should inquire whether there was a head injury before these signs appeared.
After this, during the diagnosis, a neurological examination is carried out. During this examination, the specialist is looking for signs of a neurological pathology, for example, a decrease in soreness and sensitivity of the face, strabismus. Since in most cases all types of carotid-cavernous anastomosis are formed due to traumatic brain injury, it is necessary to find other signs of this injury: bruising, bruises of soft tissues of the head, hemorrhages near the eyes, strabismus and much more.
Then the doctor should examine the fundus, as there is a likelihood of signs of swelling of the optic disc.
Diagnosis involves radiography of the skull, so that you can find the location of the fracture.
Cerebral angiography is mandatory when a special substance is injected into the bloodstream, which is visible on x-rays. After this, it is necessary to take a series of images of the head, on which should be clearly visible contrasted carotid-cavernous anastomosis.
An MRI or CT scan is also necessary for the diagnosis of the brain. These methods allow you to study this organ in layers, revealing anastomosis in it.
When the patient is diagnosed, treatment with a carotid-cavernous anastomosis is prescribed.
Treatment features
How will this neurological disease be treated? This disease is treated only surgically. If a carotid-cavernous anastomosis has been diagnosed, the operation is performed to separate the arteries and sinus.
Possible consequences and complications
If the patient does not seek the help of a neurologist in time, then he may develop various kinds of complications. One such is hemorrhage in the skull. This complication is observed in the case of rupture of the thin wall of the cavernous sinus, which is simply not adapted to such an increased blood pressure.
Complications can manifest themselves in the form of loss of eye function, that is, complete blindness.
Another possible unpleasant consequence is an acute circulatory disturbance in the brain. It occurs due to the so-called robbery effect, because the blood from the carotid internal artery, intended to feed the brain, passes into the sinus, and the brain remains without the necessary fluid.
In order to avoid such dangerous complications, you should immediately consult a specialist if you have discovered the first symptoms and signs of a carotid-cavernous anastomosis. To the right or left, these signs will manifest themselves, depending on a traumatic brain injury.
Prevention
As for preventive measures, those do not exist. They can only consist of a thorough examination of all patients who suffered from traumatic brain injuries. This is especially true in cases where a person had signs of a fracture of the base of the skull. These signs include hemorrhages around the eyes, strabismus, and much more. For early treatment, as well as eliminating the development of various complications, it is necessary to diagnose the disease as soon as possible.
Conclusion
So, we have examined what constitutes a carotid-cavernous anastomosis. When the first signs and symptoms appear, you should seek the help of a doctor, since one of the complications of this ailment is loss of vision. In most cases, the cause of this disease is a head injury. Do not ignore severe bruises, as well as hemorrhages. As mentioned earlier, prevention of carotid-cavernous anastomosis does not exist. It is only necessary to turn to a neurologist in time for various injuries. After the diagnosis, the specialist will be able to prescribe the appropriate treatment, which is just a surgical intervention.