Angiography (Including Non-Ionic Contrast)

Ionizing radiation exposure can be harmful to pregnant women and hence they are advised not to undergo an angiogram test. Damage to the fetus is one of the angiogram risks and therefore, pregnant women are advised against it. Patients who are scheduled to undergo angiogram procedure are asked to avoid eating and drinking 8 hours prior to it. Patients are asked to remove their jewellery and other accessories. Shaving is required in the armpit and groin area before an arterial puncture. An informed consent form detailing the possible complications is signed before the procedure.

The procedure involves administering a sedative for relaxation. An intravenous line is inserted into the vein. This is just a precautionary step to ensure that medication can be provided or blood products can be given in case of unwanted complications that take place during the angiography procedure.

• An antiseptic agent is used to clean the location and a local anesthetic is then administered. For the passage of the needle, a small incision is made. Something named as a stylet, which is a needle with a solid inner core, is inserted into the artery via the incision. After the puncture of the artery, the radiologist replaces the stylet with a guide wire, which is a long wire. Spurting of blood is normal during the process. Through the outer needle, the guide wire is fed into the artery that is supposed to be studied. To direct the guide wire to the correct location of the artery, a fluoroscope display is used. Once the location is spotted, the needle is removed and a catheter is placed over the guide wire’s length until it reaches the region of the study. The guide wire is then removed and now a contrast medium is injected in the region.
• The contrast medium can be injected either through a syringe or an automatic injector referred to as power injector. Before this, a small test injection is given to check that the catheter is in the right position. The patient is informed to stay as still as possible during this process. The injection can cause a little bit of dizziness, warmth, burning sensation, chest pain, irregular heartbeat, or a headache. The patient is often asked to change position to allow the study from different perspectives.
• Throughout the procedure, radiographs or fluoroscopic images are obtained in rapid succession. Because of the high pressure of the blood flow in the artery, the contrasting medium gets diluted and starts dissipating in the body. More than one automatic film changers is employed to capture the images.
• Digital image capture makes it possible to manipulate the information electronically. This is known as digital subtraction angiography or DSA. Computers make use of pixels to analyze the information better. After the completion of the X-Ray, the catheter is slowly removed and manual pressure is applied to the site for about 10 to 20 minutes with a sandbag. This allows resealing of the arterial puncture. A pressure bandage is then applied at this site.

The patient is kept under close observation for at least 6 to 12 hours if the procedure is performed on an outpatient basis. In case of a femoral artery puncture, the leg is almost kept immobile during the observation period.

Blood pressure and other vital signs are continuously monitored. A cold pack is applied to reduce swelling in the area of puncture and medications are given in case of extreme discomfort.

Hematoma may develop in a few patients. This indicates continuous bleeding from the puncture site and has to be watched for. Two to three days of complete rest is advised and driving should be avoided in the case of patients who have had fluorescein angiography. Direct exposure to sunlight should be avoided for at least 12 hours.