Digital subtraction angiography of the whole brain is a relatively new technology in the field of neurological disease diagnosis and treatment in China, and many colleagues may not know much about it yet. As an invasive test, scientific and standardized preoperative preparation and postoperative treatment can minimize complications, increase the success rate of surgery, and improve the quality of life of patients. There are four specific points as follows.
I. Indications and relative contraindications.
(A) Indications
1.Intracranial vascular lesions.
(1) Hemorrhagic lesions: intracranial aneurysm, carotid artery aneurysm, subarachnoid hemorrhage, vertebral artery aneurysm, arteriovenous malformation, dural arteriovenous fistula, carotid cavernous sinus fistula, Galen’s vein aneurysm, cavernous hemangioma, intracranial venous vascular malformation.
(2) Ischemic lesions: intracranial and intracarotid system arterial stenosis (anterior cerebral artery, middle cerebral artery, carotid artery, vertebral artery, basilar artery stenosis), intracranial vein or venous sinus thrombosis, smog disease.
2.Intracranial tumor meningioma, vascular reticulocytoma, jugular venous bullae tumor, glioma.
3.Head and neck vascular tumor nasopharyngeal fibrovascular tumor, carotid body tumor.
(II) Contraindications
1.Patient’s condition is extremely weak, serious heart, liver and kidney function damage.
2.Iodine allergy or allergic constitution.
3, Within 3 months of pregnancy (relative contraindication).
4.Infection at the puncture site, vascular stenosis, occlusion or atheromatous plaque (relative contraindication).
II. Operation steps.
(A) Preparation for the operation period
1.Hospitalization: Establish a complete medical record file and perform a comprehensive physical examination and systematic neurological examination.
2. Preoperative preparation: including skin preparation. Preoperative conversation, explanation of risks and possible postoperative complications, routine laboratory tests, coagulation Rt and liver and kidney function, etc.
3.Equipment preparation.
(1) Digital subtraction angiography machine: Timely development, subtraction, magnification, measurement and video recording functions are required, preferably with three-dimensional imaging function.
(2) Puncture needle.
(3) Guidance wire.
(4) Catheter sheath.
(5) Contrast catheter: mostly made of polyethylene impervious to X-rays, tapered end, end hole, straight or “J”-shaped, hunter head-shaped, two-way switch.
(6) high-pressure syringe and connecting tube: cerebral angiography general pressure of 150 psi (pounds per square inch).
(7) Pressurized infusion bag.
(8) Contrast agent: Non-ionic iodine solutions such as iodophoresis (omnipaque) are currently advocated. A reference measurement is given here.
Common carotid artery – 8ml/s Total 12ml
Internal carotid artery – 6ml/s Total 9ml
External carotid artery – 3ml/s total 5ml
Vertebral artery – 5ml/s total volume 7ml
(B) Intraoperative precautions
1.Local anesthesia, 1% lidocaine 5~10ml local infiltration anesthesia at the puncture site, neuroleptic anesthesia or general anesthesia with tracheal intubation for uncooperative or critically ill patients.
2, whether heparinization should be discretionary, heparin 1mg/kg, diluted intravenous injection.
3.Whether to perform controlled hypotension, as appropriate.
4.The pressurized infusion bag is connected to the tee connection tube on the side wall of the catheter sheath.
5.Monitor pulse, respiration, blood pressure, and directly monitor arterial pressure (radial artery, dorsalis pedis artery) if necessary.
(C) Postoperative precautions
1.Monitor the body temperature, pulse, respiration and blood pressure, and observe the mental, pupillary and neurological signs.
2.Observe the puncture site for bleeding, dorsalis pedis and posterior tibial artery pulsation, limb color, and pain.
3.Prevent infection and apply antibiotics.
4.Anti-cerebral vasospasm, thrombolysis, anti-seizure.
5, Perform controlled hypotension as appropriate.
6.Eating after 6h, lying in bed for 24h, braking the lower limb on the puncture side.
III. Operation methods and procedures.
1.The patient lies supine on the contrast bed, fix the head and place a measurement marker (10mm diameter steel ball), and fix the extremities.
2. Disinfection of the perineum. Up to the navel and down to the middle of both femurs.
3.Place sterile sheet.
4.The right (left) femoral artery is the puncture point, 2cm below the inguinal ligament, where the femoral pulsation is most obvious. 5~10ml of 1% lidocaine is used for local infiltration anesthesia, and the skin of the puncture point is incised 2mm with a triangular blade.
5, the operator’s left hand middle and index fingers feel the femoral artery puncture point, the right hand holds the puncture needle against the direction of blood flow and the skin at 45 °, using Seldinger modified technique to puncture and insert the catheter sheath, from the side wall of the catheter sheath tee switch connection tube back to see the arterial blood, to determine the correct, the arterial pressure infusion tube connected to the side wall of the catheter sheath tee connection tube, slowly drip saline, and fix the catheter sheath with sterile adhesive tape.
6.Under the monitoring of computer screen (or inserting a guidewire inside the catheter), the imaging catheter is sent into the femoral artery → external iliac artery → common iliac artery → abdominal aorta → thoracic aorta → aortic arch, firstly imaging the aortic arch (Figure 1), then using the “directional rotation” technique, the catheter is inserted into the left and right internal and external carotid arteries respectively, and finally from the clavicle In special cases, selective angiography of the thyrocervical trunk and cribriocervical trunk should be done on both sides.
7.After completion of the angiography, the left hand shows, middle and ring three fingers to feel the puncture point up and down, while the right hand pulls out the catheter sheath, the left hand compresses the femoral artery puncture point tightly for 15~20min, after releasing the compression to see no bleeding at the puncture point, cover with sterile gauze and add pressure bandage. External sandbag was added to compress the local area. It lasts for 6~8h.
IV. Post-operative complications.
1, puncture site. Hematoma, occlusion after vascular injury, pseudoaneurysm, arteriovenous fistula (AVF).
2, Catheter or guidewire. Resulting in intimal injury, subintimal entrapment, or even occlusion of the vessel. Catheter or guidewire fracture in the vessel, catheter knotting and folding.
3. Intracranial complications. Cerebral thrombosis, cerebral vasospasm, air embolism (pressurized infusion into), intracranial hemorrhage.
4.Contrast agent allergy.