I. When is DSA necessary?
DSA has been considered the gold standard for cerebrovascular imaging until now, and no examination (including high field intensity MRI/MRA) 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 observe their relationship with intracranial vessels.
6.To observe the condition of intracranial vascular injury during cranial trauma.
II. How to do DSA?
(1) Anesthesia: If the patient can cooperate (have the ability of autonomous behavior, clear consciousness) 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. 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 successful puncture, a special contrast tube is used in the arterial blood vessel until it reaches the neck, where there are vascular openings supplying the head bilaterally (usually 6: bilateral vertebral arteries, bilateral internal carotid arteries, and bilateral external carotid arteries). We put special contrast tubes into the arterial openings about 2 cm, then position them, and by injecting contrast, we can accurately know the size, shape, and presence of lesions of the vessel.
(2) Age: There is no clear age limit, which means that DSA can be considered as long as it is tolerated. The youngest of us has done a 5 year old and the oldest has done a 95 year old. Of course, the necessary examination indexes (ECG, chest X-ray, liver and kidney function, electrolytes, coagulation function, etc.) are not obviously contraindicated before doing the examination.
Third, is it dangerous to do cerebral angiography?
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 stragglers. 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 present, there are no cases of neurological dysfunction due to angiography in our hospital.
(2) Non-neurological complications: Non-neurological complications of cerebral angiography via the femoral artery 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 in our hospital is slightly lower than the above data.
IV. What do I need to pay attention to after imaging?
(1) Bed rest, straightening and braking of the lower limb on the puncture side, generally need not to bend for 24 hours, which means that the urine and stool need to be solved in bed within 24 hours. At present, there is a material specially 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 four times, then every 30 minutes for a total of two times, and then every hour for a total of two times.
Promptly notify the physician if there is
a. bleeding or hematoma formation at the puncture site
b. distal segment of the puncture site is not palpable by pulsation
(3) Vital signs monitoring, start once every 1 hour for 2 consecutive times, then once every 2 hours for 2 consecutive times, and finally change to once every 4 hours until 24 hours.