ANGIOGRAPHY. INTERVENTIONAL MEDICINE.

CLINICAL FEATURES.KRISTINA SAAR

YVEM21

INTERVENTIONAL RADIOLOGY

A subspecialty which provides minimally invasive techniques with the help of imaging modalities to diagnose or treat a condition.

Minimally invasiveLocal anesthesiaEarly recovery

ANGIOGRAPHYAngiography – The radiologic examination of vessels after the introduction of a contrast medium. The key ingredient in most radiographic contrast media is iodine. Angiograms can also be obtained using computed tomography (CT) by injecting contrast medium into a vein in the arm, or by magnetic resonance imaging (MRI). CT or MRI angiography only show the appearances of the blood vessel, and cannot be used for treatment procedures.

Examination principle.

To the examined vessel is injected contrast agent based on iodine.This can be done in two ways:

Puncture: if the vessel is located superficially, then contrast agent is injected with a syringe.Catherization: it is required if the artery or veinna lies deep beneath the skin.

Angiography is used in….• Oncology - detect tumors and their metastases, which are branched

capillary network.• Phlebology - defines space narrowing and blockage of veins, their

congenital pathology, blood clots, atherosclerotic lesions.• Vascular surgery - used in preparation for operations on vessels to clarify

their position and structure.• Neurology - cerebral angiography reveals an aneurysm, hematoma, brain

tumor, as well as the location of bleeding in hemorrhagic stroke.• Pulmonology - reveals defects lung development and the source of

bleeding.

Depending on the research objectives angiography may be:• Total - examines all the vessels;• Election - contrasted individual vessels .

Common Indications for Angiography

• Aneurysm• Vasoconstriction• Malformation• Violation of patency of blood vessels

(atherosclerosis, thrombosis)• Injuries and malformations of various organs,

tumors, etc.

CONSENT AND PREPROCEDURAL PATIENT CARE

• A medical history should be obtained before the procedure is begun. This should include questions intended to assess the patient's ability to tolerate the contrast injection (e.g., allergy history, cardiac/pulmonary status, renal function). The patient also will be interviewed regarding medication history and symptoms. Medication history is important because some medications are anticoagulants and will cause excessive bleeding during and after the procedure. Knowing the medication history is also important when one is selecting the premedication. Previous laboratory reports and other pertinent data are reviewed as well.

• A detailed explanation of the procedure will be given to the patient, which is important to ensure full understanding and cooperation. The explanation will include possible risks and complications of the procedure, so that the patient is fully informed before signing the consent

CONSENT AND PREPROCEDURAL PATIENT CARE

• Solid food is withheld for approximately 8 hours before the procedure to reduce the risk for aspiration. However, making sure that the patient is well hydrated is important to reduce the risk for contrast-induced renal damage.

• Premedication usually is given to patients before the procedure to help them relax. The patient may be made more comfortable on the table by placing a sponge under the knees to reduce strain on the back. Vital signs are obtained and recorded, and pulse in the extremity distal to the selected puncture site is checked. The puncture site is shaved, cleaned, and draped.

• Continual communication and monitoring of the patient by the technologist and the rest of the angiography team will greatly alleviate patient discomfort and fear.

How angiography procedure is performed?Angiography for different kind of vessels is performed by SINGLE ALGORITHM.

Before the procedure i/m is administered a sedative and an antihistamine medication. This helps to reduce anxiety and prevent the development of allergic reactions to contrast agent. The disired area of the skin is treated with antiseptic.

Subcutaneously is administered the anesthetic Lidocaine. It anaesthetizes the area where will be done the puncture. On the skin is made a small cut to access the artery.

Set the introducer - short hollow tube. In the examined vessel, inject a solution of Novocaine, to prevent vasospasm and reduce the irritant action of contrast agents.

Inside the introducer is inserted catheter (a thin flexible tube with a diameter of 1.5-2 mm). It is pushed to the mouth of the examinated vessel under x-ray control. Contrast medium injected (ex. Urografin®, Hypaque® etc.) and photos are taken. If necessary this step is repeated 2-3 times. After the catheter is removed and imposed a sterile pressure bandage.

6-10 hours recommended to stay in bed to prevent formation of a blood clot.

The catheter insertion is chosen as close as possible to the area that should be examined. This allows to minimize trauma to the vessels and the amount of contrast.

Dilatator

Guidewire

Introducer

Seldinger Technique

A commonly used method for

catheterization is the Seldinger

technique. This technique was

developed by Dr. Sven Seldinger in

the 1950s and remains popular

today. It is a percutaneous (through

the skin) technique that can be used

for arterial or venous access.

• Four vessels are typically considered for catheterization: femoral, axillary, brachial, and radial. The angiographer will make the selection based on the strong presence of a pulse and the absence of vessel disease.

• The femoral artery is the preferred site for an arterial puncture because of its size and easily accessible location.

RISKS AND COMPLICATIONS• Bleeding at puncture site: this usually can be controlled by

applying compression

• Thrombus formation: blood clot may form in a vessel and

disrupt the flow to distal parts

• Embolus formation –plaque dislodged from vessel wall by

catheter

• Dissection of vessel: the catheter may tear the intima of a vessel• Infection of puncture site: this is caused by contamination of

the sterile field• Contrast media reaction: this may be mild, moderate, or severe

Contraindications for angiography• Angiography is contraindicated in cases when the procedure may worsen

the patient's condition or cause complications!!!!!!!!!!!!

• ACUTE INFECTIOUS AND INFLAMMATORY DISEASES. With the active inflammatory process of the study can cause into the blood of a large number of bacteria and viruses. This increases the risk of inflammation of blood vessels (arteritis, phlebitis) and suppuration at the injection catheter.

•MENTAL ILLNESS. During the procedure the patient is awake. He should strictly abide all the instructions of doctors and to report changes in your health. In mental pathology, it is impossible, to the same stress during the procedure may cause deterioration.

•EXPRESSED HEART FAILURE. During angiography may be a decrease or increase in blood pressure, as well as disruptions in heart associated with stress.

• RENAL FAILURE. A contrast agent having irritant effect on the kidneys and impaired excretion of urine causes retention of the drug in the body.

• DECOMPENSATED LIVER FAILURE. Stress and the introduction of contrast agents can cause hepatic coma.

• Excessive anxiety (might require general anaesthesia).• Inability to lie flat or still (might require general anaesthesia

ALLERGIC TO IODINE. If you are hypersensitive can develop severe allergic reactions: bullous toxic dermatitis, angioedema, and anaphylactoid shock.

DISORDERS OF BLOOD CLOTTING. When the blood clotting is reduced the risk of bleeding will increase, when high – can form a blood clot.

THROMBOPHLEBITIS. When patient have inflammation of a vein, then contrast agent can increase inflammation and can cause obstruction of the vessel or removal a blood clot.

PREGNANCY. X-ray radiation can cause malformations in the fetus.

In the presence of contraindications to angiography, it is possible to replace MRI or ultrasound examination of the blood vessels.

POSTPROCEDURAL CARE

• After the angiographic procedure has been completed, the catheter is removed and compression is applied to the puncture site. The patient remains on bed rest for a minimum of 4 hours, but the head of the bed/stretcher may be elevated approximately 30°.

• During this time, the patient is monitored, and vital signs and the peripheral pulse distal to the puncture site are regularly checked. The extremity is also checked for warmth, color, and numbness to ensure that circulation has not been disrupted. Oral fluids are given and analgesics are provided if required.

• Patients should be instructed on what to do if the puncture site spontaneously begins to bleed: apply pressure and call for help.