The former life of cerebral angiography
Cerebral angiography is an angiographic procedure that provides images of the blood vessels in the brain, thus allowing the detection of vascular abnormalities in the brain such as arteriovenous malformations and aneurysms. It was invented in 1927 by the Portuguese physician Antonio Egas Moniz, who also invented the contrast agent used in cerebral angiography.
The method involves inserting a catheter into a large artery (such as the carotid and femoral arteries), then passing it through the circulatory system to reach the carotid and vertebral arteries, and injecting the contrast down here, taking a series of pictures after it reaches the arterial system of the brain, until it reaches the venous system and is fully visible and finished. In the early days, the DSA machine was limited in performance and image quality due to greater trauma and a smaller scope of examination.
Cerebral angiography in the present day
Through nearly a century of development, mainly including advances in digital subtraction angiography (DSA) machines and interventional materials, cerebral angiography has developed rapidly and is widely used in clinical practice as the current gold standard for diagnosing cerebrovascular disease, becoming the “gold standard” for diagnosing cerebrovascular disease. It has become the “gold standard” for the diagnosis of cerebrovascular disease. This examination is superior to ultrasound, CTA or MRA, which can be used as a screening tool before performing DSA examination, but cannot be completely replaced.
With DSA, we can accurately understand the number, location, size, morphology, and relationship with surrounding vessels of vascular lesions, as well as initially predict/understand the progression of the disease: risk of bleeding, risk of infarction, etc., whether and how interventions are needed, etc. Its unique advantages are.
1. Super-selective intravascular visualization;
2.Dynamic display of the full time course of cerebral circulation, and vascular compensation;
3. 3D display of more anatomical details and cerebral hemodynamics showing kinetic information (4D-DSA).
What is cerebral angiography all about?
Is cerebral angiography a test, or a procedure? Cerebral angiography is an invasive test and the basis for many interventional procedures. When is a DSA needed?
Intracranial vascular diseases such as atherosclerosis, embolism, stenosis, occlusive disease, arteriopathy, arteriovenous malformation, arterial entrapment, arteriovenous fistula, moyamoya disease, Takayasu disease, traumatic cerebrovascular injury, etc. Search for causes of cerebral hemorrhage and cerebral infarction.
Intracranial occupying lesions, such as intracranial tumors and hematomas, to understand tumor blood supply and relationship with blood vessels.
Suspect venous cerebrovascular disease.
Observe the status of cerebrovascular circulation after surgery, or review after treatment of head, face and intracranial vascular or tumor diseases.
How exactly is DSA done?
If the patient can cooperate (capable of autonomous behavior and clear consciousness), just local anesthesia is needed, but for agitated (such as unconscious), too young, etc., we need general anesthesia considering that the examination process may move around and affect the quality of imaging.
There is no definite age limit for doing imaging, which means that DSA examination can be considered as long as it is tolerated. Of course, the necessary examination indexes (ECG, chest X-ray, blood routine, liver and kidney function, electrolytes, coagulation function, etc.) before doing the examination are not obviously contraindicated before the examination. There is no obvious contraindication to whether or not to take anticoagulant drugs such as aspirin, but if there are patients with systemic atherosclerosis, attention should be paid to possible puncture or pathway difficulties.
The puncture site is usually anesthetized with 2 to 3 ml of local anesthetic medication at the puncture site (usually about 1 cm below the groin on one side), and then the femoral artery is punctured. After successful puncture, a special contrast tube is used in the arterial vessel until it reaches the neck, which has vascular openings supplying the head bilaterally (usually 6: bilateral vertebral arteries, bilateral internal carotid arteries, and bilateral external carotid arteries). A special contrast tube is placed into the artery opening about 2 cm, then positioned, and by injecting contrast, the size, shape, and presence of lesions of that vessel can be accurately known.
How dangerous is DSA?
DSA is strictly an invasive test, but as long as it is invasive, there are risks, but clinically the risk of complications under strict operation is very small and almost negligible. However, because it is invasive, we should know that non-invasive tests related to blood vessels should be done before performing DSA, including: ultrasound of carotid, vertebral, and subclavian artery openings, intracranial TCD (transcranial multispectral ultrasound), cranial MRA, and CTA. If these tests suggest the presence of cerebrovascular abnormalities, or if further details are needed, DSA can be considered.
The most common neurological complication of DSA is an ischemic event secondary to thromboembolism or air embolism caused by the catheter or guidewire. Other causes include atherosclerotic platelet rupture and vascular stray layers. Other less common neurological complications include transient cutaneous equilibrium and amnesia. Very few angiograms may induce rupture of aneurysms, vascular malformations, etc. because of slight changes in intracranial pressure, but the chances are small.
Current domestic and international statistics show that the overall incidence of neurological complications is 0.8% and permanent is 0.07%, meaning that 7 out of 10,000 angiography patients may develop permanent neurological dysfunction. At our hospital, there have been no cases of neurological dysfunction due to angiography.
Non-neurological complications: Non-neurological complications of transfemoral cerebral angiography include: inguinal and retroperitoneal hematomas, allergic reactions, femoral artery pseudoaneurysms, lower extremity thromboembolism, nephropathy, and pulmonary embolism. In the current national and international retrospective analysis of angiography, the incidence of hematoma was 0.04% and skin allergy 0.1%. The occurrence of these cases in our hospital is slightly lower than the above data.
How to manage after DSA procedure?
Bed rest. The lower extremity on the puncture side is straightened and braked, and generally needs to be unbendable for 24 hours, which means that urination and defecation need to be solved in bed within 24 hours. There is a material specifically used to seal the postoperative vascular puncture opening, which enables the patient to get out of bed earlier than 4 hours. Also, patients who are able to do so can drink more water to speed up the elimination of the contrast agent.
The arterial pulsation at the puncture site and its distal segment should be checked regularly after surgery in order to detect sometimes lower extremity thrombosis in a timely manner, usually every 15 minutes for a total of 4 times, then every 30 minutes for a total of 2 times, and then every hour for a total of 2 times. Notify the physician promptly if the following occur: a. bleeding or hematoma formation at the puncture site; b. puncture; distal pulsation cannot be palpated.
Vital signs monitoring: start every 1 hour for 2 consecutive times, then every 2 hours for 2 consecutive times, and finally change to every 4 hours until 24 hours.