This is a procedure that is performed to look for PAVM. The test basically involves inserting a catheter (thin rubber tube) through a large vein in either your leg or neck, and passing it up into the arteries of your lungs. This is often recommended in the evaluation of patients with HHT, pulmonary hypertension, and some other conditions.
Basically, this test allows us to accurately assess the number and severity of PAVM. The only other test that helps with this assessment is a CT scan of the lungs. However, the angiogram gives us additional information to help us plan treatment of pulmonary AVM. Also, AVM can sometimes be treated with embolization at the same time as the original pulmonary angiogram.
Most patients will be admitted to the hospital for a same day procedure. Before the angiogram, a small IV (intravenous) catheter will be inserted into a vein in your arm and you will be given an intravenous sedatives to help relax you. Very anxious patients, especially children, may need to be "put to sleep" (general anesthesia) for this test. At the time of the angiogram, you will be moved to the Invasive Radiology Lab, where the angiogram will actually take place. Preparation in the Lab will include cleaning the area where the angiogram catheter will be inserted (the "angio site") with betadine to make it sterile and covering you with a sterile sheet to minimize any chance of infection. If the angio site is in the leg, the groin area will also be shaved to minimize infection. Once the angio site is prepared, your doctor will numb the skin with a local anesthetic such as lidocaine. Most patients experience some mild pain and burning while the skin is being numbed up. If you are allergic to lidocaine please let your doctor know so that a different medicine can be used. After your skin is adequately numb, a catheter (long rubber tube) will be inserted through the vein and then passed up through the heart and into the blood vessels of the lung.Your doctor may use a fluoroscope (X-ray machine) to help guide the catheter. While the catheter is inserted, your doctor will make one or more injections of "X-ray dye" into the pulmonary arteries (lung arteries) to help us see AVM.
The entire angiogram (including preparation in the Lab) will take 1 to 4 hours. If you have problems with frequent urination, you may want to have a bladder catheter inserted before you go to the Lab to avoid the discomfort of "holding your bladder." After the procedure is over, the catheter will be removed and you will go back to your room to be observed for 2 to 6 hours. You will then be discharged home as long as there are no complications. If your procedure is completed by early afternoon, you may be able to go home later that day; otherwise, you may need to stay overnight.
Special preparation is usually not necessary. You should of course get plenty of rest the night before. If your angiogram is scheduled for the morning you should not eat after midnight. We may ask you to stop certain medications before your angiogram. If you are taking warfarin, we will have you stop this. You will receive more detailed instructions regarding your medications at the time that you are scheduled. You should also avoid drinking coffee or other caffeinated beverages the morning of your angiogram.
Overall, this is a safe procedure and the majority of patients have no serious complications whatsoever. Since we are inserting a catheter into your vein, there is a small risk of bleeding and infection. We take certain precautions such as testing you for bleeding problems and preparing the angio site carefully to minimize these risks. If a vein in your neck is used as a cath site, there is a small risk (about 1%) of a collapsed lung; this may require insertion of a tube between the ribs to let the lung expand again. The most common complication is irregular heart beats from the catheter irritating the heart. We will be monitoring your heart beat the entire time so that we can treat these by pulling the catheter back or using medicines if necessary.You may experience a hot or burning sensation when the X-ray dye is injected. The X-ray dye can occasionally injure the kidneys and even cause kidney failure. The chance of kidney failure that is serious enough to require temporary dialysis is <0.5% in patients with normal kidney function at the start of the test, but is higher if your kidney function is not normal to begin with. Your kidney function will be tested before the angiogram to better assess your risk. Other rare complications include perforation of the heart and even death. There may be other rare and unforeseen complications. Overall, the chance of a life-threatening complication or death is less than 0.5% for the average patient.
While doctors at your local hospital may be qualified to perform a basic pulmonary angiogram and may have even performed embolization, the success of this procedure depends on experience and use of special techniques. We therefore strongly recommend that you have your angiogram performed by a doctor experienced in managing patients with PAVM, as is the case at our Pulmonary Vascular Disease Center.