Angiography is an invasive X-ray examination of blood vessels with the preliminary introduction of special radiopaque preparations. Depending on the type of vessels studied (arterial, venous, lymphatic), arteriography, phlebography and lymphography are distinguished. It can be general (in the study of all major arteries and veins) and selective (in the study of vessels of a specific anatomical region). The latter may include cerebral angiography, angiopulmonography, coronary angiography, renal angiography, retinal angiography, etc. Angiography allows you to visualize vessels of any caliber, assess their architectonics, identify anomalies (aneurysms, constrictions, malformations), damage, obstacles to blood flow (blood clots, atherosclerotic lesions).
Types of angiography
Taking into account the characteristics of the studied vessels, arteriography, phlebography (venography), kappilarography and lymphography are distinguished. Taking into account the scale of the study, general and selective (local) angiography are distinguished. There are the following types of selective angiography:
- Cerebral – examination of the vessels of the brain.
- Coronary – examination of the heart vessels.
- Peripheral – examination of the vessels of the upper and lower extremities.
- Aortography: thoracic (examination of the thoracic aorta) and abdominal (examination of the abdominal aorta).
- Angiopulmonography is a study of pulmonary vessels.
- Portography is a study of the portal vein.
- Renal – examination of the vessels of the kidneys.
Methodology of conducting
Within 4 hours before the procedure, the patient is forbidden to eat and drink. Before starting angiography, the patient is placed on a special table. A tranquilizer is administered intramuscularly to reduce anxiety and an antihistamine to prevent allergies. An artery, vein or lymphatic vessel is selected, the skin area above the vessel is treated with an antiseptic drug, local anesthesia is performed, a small incision is made on the skin and an introducer is installed (a special device for installing a catheter through which a contrast agent will be injected into the vessel during angiography).
A catheter is inserted through the introducer and pushed to the vessel in the study area. An X-ray is taken to make sure that the catheter is in the right place, and then an X-ray contrast agent (triiotrast, cardiotrast, urographin, hypac) is injected into the catheter and a series of images are taken. If necessary, the procedure is repeated several times until the data necessary for diagnosis, determination of treatment tactics, etc. are obtained (depending on the purposes of angiography).
At the end of the study, the catheter is removed, the incision site is closed with a sterile cloth and a bandage is applied. Within 6-10 hours after angiography, the patient is advised to observe bed rest for the prevention of thrombosis. Iodine-containing contrast agents can have a negative effect on the kidneys, so the patient is recommended to drink more fluids to reduce the concentration of the drug in the blood and facilitate its excretion in the urine.
The grounds for conducting cerebral angiography are causeless dizziness and headaches, recurrent episodes of nausea, fainting and pre-fainting states of unclear etiology, residual disorders after traumatic brain injuries, neurocirculatory dystonia, acute or chronic cerebral ischemia, a history of micro-stroke or stroke. The purpose of angiography is to make a diagnosis, choose treatment tactics, determine the effectiveness of therapy already performed, or assess the dynamics of the patient’s condition in the long-term period after injuries and diseases.
Angiography allows you to diagnose circulatory disorders by hemorrhagic (aneurysms, vascular diverticula, angiomas) and ischemic (atherosclerotic changes, blood flow disorders, vascular deformities) type. In addition, according to the study, changes in the vascular pattern characteristic of benign and malignant neoplasms of the brain are revealed. To increase the information content, along with classical radiography, vascular CT is used, which allows to obtain layered images of brain vessels and their three-dimensional computer image.
Indications for coronary angiography are severe stable angina pectoris, ineffectiveness of drug therapy for angina pectoris, a previous myocardial infarction accompanied by clinical death or severe rhythm disturbances, a high probability of sudden death from cardiac arrest, myocardial infarction or the appearance of symptoms of angina pectoris within a year after stenting, the period of preparation for heart valve surgery in patients older than 40 years, the presence of contraindications for ultrasound or ECG with load, as well as clarification of the diagnosis with ambiguous data, obtained in the course of other studies. The purpose of angiography is to assess the degree of blood flow disorders, diagnose and determine treatment tactics.
Based on the results of the study, a decision may be made to conduct conservative therapy, coronary artery bypass grafting or artery stenting. Angiography of coronary vessels can detect stenosis (narrowing of the vessel), occlusion (blockage of the vessel), aneurysm (bulging of the vessel wall) and calcinosis (deposition of calcium salts in the vessel wall). Narrowing of the vessel lumen by 75 percent or more is an indication for surgical intervention on the coronary arteries.
Extremity vessels angiography
Indications for angiography of the vessels of the extremities are diseases and pathological changes of the arteries (atherosclerosis, obliterating endarteritis, thromboembolism, diverticulitis, delaminating aneurysm), venous diseases (phlebitis, thrombophlebitis of superficial veins), diabetic foot syndrome in diabetes mellitus, traumatic vascular injuries of the extremities, trophic ulcers and purulent necrotic lesions of the extremities, clarification of the surgical treatment plan for injuries and diseases veins and arteries and assessment of vascular condition in the postoperative period.
In clinical practice, angiography of the vessels of the lower extremities is more often required, due to the widespread prevalence of diseases of the arteries and veins in this area. Angiography of the vessels of the upper extremities is usually performed for injuries. In case of venous lesions, phlebography is prescribed, in case of injuries and diseases of the arteries – arteriography.
The purpose of the examination is to make a diagnosis, determine the tactics of conservative and surgical treatment, or evaluate the effectiveness of therapy. Angiography of the lower extremities makes it possible to assess the condition of the main vessels, the number of collaterals and their ability to provide adequate blood circulation after ligation of a large vessel, the condition of the walls of arteries and veins (the presence of blood clots and atherosclerotic plaques, pathological expansion or narrowing of the lumen).