I have been encountering many patients and families who need cerebral angiography (DSA) for cerebrovascular disease asking me, “What is cerebral angiography all about?” “How dangerous is it?” Many patients and their family members are aware of the possible need for cerebral angiography before the consultation, but have no way to understand this knowledge, so they have doubts and even hesitation.
I. When is DSA needed?
DSA has been considered the gold standard for cerebrovascular imaging until now, and there is no test (including high field strength MRI/MRA) that is more accurate than DSA for understanding cerebrovascular lesions. The risk of bleeding, risk of infarction, etc., whether intervention is needed, how to intervene, etc.
The need for DSA broadly includes the following.
1, intracranial hemorrhagic lesions, who need to find the cause of bleeding
2, intracranial ischemic lesions, observation of the extent, degree and collateral circulation of the lesion
3, observation of intracranial vascular development to exclude vascular developmental abnormalities and variants
4, intracranial occupying lesions, those who need to understand the source of blood supply, the richness of blood supply and the relationship between the lesion and important blood vessels
5.To understand certain extracranial pathological crossings and to observe their relationship with intracranial vessels.
6.To observe the condition of intracranial vascular injury during cranial trauma.
Second, how to do DSA?
1, if the patient can cooperate (have the ability to act on their own, conscious) patients just need local anesthesia, but for restless (such as unconscious), too young, etc., consider the examination process may be moving around, affecting the quality of imaging, we need general anesthesia.
2, the age of doing imaging: there is no clear age limit, that is, as long as they can tolerate can consider DSA examination. The youngest of us has done 5 years old, and the oldest has done 95 years old. Of course, the necessary examination indexes (ECG, chest X-ray, liver and kidney function, electrolytes, coagulation function, etc.) before doing the examination are not obviously contraindicated before the examination.
3. Generally, 2-3 ml of local anesthetic drug is used to anesthetize the puncture site (usually about 1 cm below the groin on one side), and then the femoral artery is punctured. After a successful puncture, a special contrast tube is used in the arterial vessels until it reaches the neck, where there are vascular openings supplying the head on both sides of the neck (usually 6: bilateral vertebral arteries, bilateral internal carotid arteries, and bilateral external carotid arteries). We put a special contrast tube into the arterial openings about 2 cm, then position it, and by injecting contrast, we can accurately know the size, shape, and presence of lesions of that vessel.
III. Dangerousness
DSA is strictly an invasive test and cannot be considered a surgery, but as long as it is invasive, there will be risks.
(1) Neurological complications of DSA: The most common are ischemic events secondary to thromboembolism or air embolism caused by catheters and guidewires. Other causes include atherosclerotic platelet rupture and vascular stray layers. Other less common neurological complications include transient skin blindness 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 neurological complication rate is 0.8%, and the permanent rate is 0.07%, meaning that 7 out of 10,000 angiographic patients may develop permanent neurological dysfunction.
(2) Non-neurological complications: Non-neurological complications of transfemoral cerebral angiography include: inguinal and retroperitoneal hematoma, allergic reaction, femoral artery pseudoaneurysm, 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 the above cases in our hospital is slightly lower than the above data.
IV. Postoperative treatment
1.Bed rest: straightening and braking of the lower limb on the punctured side is generally required not to bend for 24 hours, which means that urination and defecation need to be solved in bed within 24 hours. At present, there is a material specifically used to seal the postoperative vascular puncture opening, which can enable the patient to get out of bed 12 hours earlier, but the material is more expensive (about 2999 yuan), and patients can choose by themselves.
2. The arterial pulsation at the puncture site and its distal segment should be checked regularly after surgery in order to detect sometimes lower limb thrombosis in time, usually every 15 minutes for a total of 4 times, then every 30 minutes for a total of 2 times, and then every 1 hour for a total of 2 times. Promptly notify the physician if.
(1) Bleeding or hematoma formation at the puncture site
(2) distal segment of the puncture site is not palpable by pulsation
3. Vital signs monitoring: once every 1 hour for 2 consecutive times at the beginning, then once every 2 hours for 2 consecutive times, and finally change to once every 4 hours until 24 hours.