I. Overview
Internal carotid cavernous fistula (CCF) refers to the rupture of the internal carotid artery itself or its branches in the cavernous sinus segment, resulting in abnormal arterial and venous communication with the cavernous sinus, leading to an increase in pressure in the cavernous sinus and a series of clinical manifestations.
The cavernous sinus is the only structure in the body where arteries pass through veins, and because of the high incidence of craniocerebral trauma, the cavernous sinus area is highly susceptible to arteriovenous fistulas, of which TCCF accounts for more than 70%. Since 1974, when Serbinenko first reported the successful treatment of TCCF with detachable balloon embolization, endovascular treatment has become the preferred treatment for CCF with the rapid development of medical imaging and continuous improvement of embolization materials, as well as the continuous improvement of embolization techniques over the past 30 years.
II. Etiology
Complex etiology More than 75% of the cases are caused by trauma, such as skull base fracture laceration, bone fragment puncture, foreign body penetration injury, firearm injury; other factors can occur spontaneous CCF, such as aneurysm rupture, arteritis, atherosclerosis, spontaneous CCF during pregnancy. different etiology will lead to different treatment process and effect.
III. Clinical manifestations
Typical clinical manifestations The diagnosis of CCF is mainly based on its typical clinical manifestations and typical ocular signs, especially when combined with a history of cranial trauma to establish the diagnosis. Cranial CT and MR can find proptosis, enhanced cavernous sinus imaging or ophthalmic vein thickening, which can be used as an auxiliary diagnosis. Typical clinical manifestations are as follows.
(1) Pulsatile proptosis (more than 95% in the literature), caused by increased pressure in the cavernous sinus, which affects the reflux of the ophthalmic vein;
(2) Tremor and murmur, which seriously affects the patient’s work and rest, is the main reason for patients to visit the clinic, so the treatment process is based on the disappearance of the murmur;
(3) Bulbar conjunctival edema and congestion, caused by restricted reflux in the ophthalmic vein, is one of the reasons why patients are seen;
(4) Restriction of eye movements (uncommon) due to compression of the cranial nerve passing through the cavernous sinus;
(5) Visual acuity loss;
(6) neurological dysfunction and subarachnoid hemorrhage, which appear early in the trauma and are related to the site and extent of the trauma;
(7) Fatal rhinorrhea, which may be related to pseudoaneurysm.
IV. Diagnosis and differential diagnosis
Cerebral angiography can provide comprehensive information for endovascular treatment. However, it should be distinguished from other causes of proptosis.
(1) Proptosis goiter;
(2) Intraorbital tumors;
(3) Intraorbital vascular tumors;
(4) cavernous sinus thrombosis;
(5) meningeal bulge. Experienced doctors are often able to make correct judgments.
V. Treatment
The purpose of treatment of CCF
(1) To protect vision;
(2) To eliminate murmur;
(3) To retract the eye;
(4) to prevent cerebral ischemia or hemorrhage.
Since the clinical symptoms of CCF are progressively worse, effective measures must be taken to treat it in order to reduce the flow of arterial blood into the cavernous sinus. In simple internal carotid cavernous sinus fistulas, the fistula can usually be occluded with a detachable balloon, which is a short, effective, and inexpensive procedure. In larger fistulas, sometimes the fistula cannot be occluded even if multiple balloons are placed, and embolization with a spring ring + ONXY gel is required instead. For carotid cavernous sinus fistulas with meningeal vessels involved in blood supply, i.e., dural arteriovenous fistulas in the cavernous sinus area, a transvenous approach with embolization using spring coils + ONXY glue can be used and can be cured.