1] What is MR (magnetic resonance) angiography?
MRI (magnetic resonance imaging) uses magnetic fields and radio waves to produce two-dimensional or three-dimensional images of the structures inside your body, such as your heart, brain or blood vessels. When this scanning method is applied to the blood vessels, it is also sometimes referred to as MRA (magnetic resonance angiography).
2] What is an angiogram?
An angiogram is an imaging test that uses x-rays to view your body’s blood vessels. Physicians often use this test to study narrow, blocked, enlarged, or malformed arteries or veins in many parts of your body, including your brain, heart, abdomen, and legs. When the arteries are studied, the test is also called an arteriogram. If the veins are studied, it is called a venogram. To create the x-ray images, your physician will inject a liquid, sometimes called "dye", through a thin, flexible tube, called a catheter. He or she threads the catheter into the desired artery or vein from an access point. The access point is usually in your groin but it can also be in your arm or, less commonly, a blood vessel in another location. This "dye, " properly called contrast, makes the blood flowing inside the blood vessels visible on an x-ray. The contrast is later eliminated from your body through your kidneys and your urine.
3] Risk of Heart Attack / Heart Failure / Stroke with Vascular Surgery
Yes doctor…I understand the procedure, but what is the risk…. While most vascular procedures are so minimally invasive that the risks are quite low, especially procedures on veins. However, the risk increases significantly, when we get into vascular problems involving carotid artery stenosis (narrowing of the arteries in the neck which can cause strokes), aortic aneurysms (ballooning of the blood vessels which can burst and cause instantaneous death) or severe shortage of blood supply to the lower legs – leg ischemia. In such cases, aside from the risks inherent to the part of the body where the operation is being performed, the main risk is to the heart – “Heart attack” as most of folks lump all things heart related. The risk is not only related to “what” the risk is, but “how much” is the risk? This “quantification” of the risk is important so that measures can be taken to “reduce risk”. Why all the fuss…..because anybody having a heart attack or heart failure around the time of an operation has a 30% - 50% chance of dying. So to “risk stratify” patients several indices have been developed. The Goldman Risk Index was developed in the 1970’s, but the limitation was that when they made this index, they did not include very many vascular patients in the original study and so this index is not focused on vascular patients. To overcome this limitation, the Eagle’s Cardiac Risk Index was devised for patients undergoing vascular surgery. Multivariate analysis has shown that the following factors predict an adverse event following vascular surgery: Q waves on the electrocardiogram (ECG) History of angina pectoris History of ventricular ectopy requiring treatment (most specific for predicting events) Diabetes mellitus requiring therapy other than diet Age older than 70 years Thallium redistribution (most sensitive for predicting events) Ischemic electrocardiographic changes during or after dipyridamole infusion Combining both the clinical data and thallium imaging was more sensitive and specific than either alone in predicting postoperative complications. In this model, the following can be noted: No clinical predictors of risk factors: 3.1% risk of perioperative ischemic cardiac complications Thallium redistribution in addition to one or two clinical predictors: 29.6% risk of Three clinical predictors: 50% risk of perioperative cardiac complications More recently, the Vascular Study Group of New England has developed the Vascular Study Group Cardiac Risk Index (VSG – CI) for the patients mentioned at the beginning of this article. This is the current Standard used by vascular surgeons at most academic medical centers. This is the current risk calculator used by us at Vascular.ae, across all our practices in the Middle East.