Angiography and Angioplasty


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Angiography and Angioplasty

  2. 2. Fluoroscopy Fluoroscopy is an imaging technique commonly used by  physicians to obtain real-time moving images of the internal structures of a patient through the use of a fluoroscope. In its simplest form, a fluoroscope consists of an X-ray source and fluorescent screen between which a patient is placed. However, modern fluoroscopes couple the screen to an  X-ray image intensifier and CCD video camera allowing the images to be recorded and played on a monitor.
  3. 3.  The word itself comes from the Greek words angeion, "vessel", and graphein, "to write or record". Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins and the  heart chambers. The film or image of the blood vessels is called an angiograph, or more commonly, an angiogram. The term angiography is strictly defined as based on  projectional radiography; however, the term has been applied to newer vascular imaging techniques such as CT angiography and  MR angiography. The term isotope angiography has also been used, although this more correctly is referred to as  isotope perfusion scanning.
  4. 4. The technique was initially developed to provide contrasted x-ray cerebral angiography in order to diagnose several kinds of nervous diseases, such as tumour, coronary heart disease and arteriovenous malformations. It enables the radiologist or cardiologist to see stenosis  (blockage or narrowing) inside the vessel which may be inhibiting the flow of blood and causing pain. These blockages may in future lead to heart attack.
  5. 5. Coronary Angiography Micro angiography Neurovascular or cerebral angiography Peripheral Angiography
  6. 6. A long wire called catheter is inserted inside the artery of the leg, near the thigh crease called Groin. This catheter is then pushed against the blood flow towards the heart blindly. An eye is kept on the tip of the catheter through the fluoroscopy monitor. Once the tip reaches the heart area, further manipulation is done to push the tip in one of the coronary arteries. Inside the coronary tube, after a lot of trial and error, a radioactive dye is injected through the hole in the catheter inside the coronary tubes and further fluoroscopy photographs are taken.  The tip of the catheter is again withdrawn, negotiated inside another coronary tube and the same photos are taken.  If the dye seems to fill up the coronary tubes completely, the blockages are probably not there. If the dye can not fill the tubes (as roughly seen in the photos taken) inside, it is taken as filling defect and indirectly interpreted as blockages.
  7. 7. Angioplasty has come to include all manner of vascular interventions typically performed in a minimally invasive or  percutaneous method. Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel; typically as a result of  atherosclerosis Blockages in the arteries may be caused by hypertension,  diabetes, sedentary lifestyle, smoking, high cholesterol levels, diets high in saturated fats, and cardiovascular disease. Removing blockages is done with angioplasty.
  8. 8. When there are blockages in the blood vessels of our body then these can be very harmful to us. These may not let the free flow of the blood. All parts of the body may not get requisite supply of the blood. Angioplasty is used to tackle with this problem. In this blockages are removed from the blood vessels so as to maintain the blood supply to the organ.
  9. 9. Cerebral arteries angioplasty Carotid angioplasty Renal artery angioplasty Coronary angioplasty  Peripheral angioplasty
  10. 10. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations. It is then inflated to a fixed size using water pressures some 75 to 500 times normal blood pressure. The balloon crushes the fatty deposits, so opening up the blood vessel to improved flow, and the balloon is then collapsed and withdrawn.
  11. 11. Stents are used in the process of angioplasty so as to make the cross-section of the blood vessel wider and thereby curing the blockages in the vessel. The blockages in the blood vessel may be very harmful. Stents hold the walls of the vessel and thus not let it sag or it’s area to shrink.
  12. 12. The materials used in coronary stents must be flexible, supportive, capable of expansion, and biocompatible. The ideal coronary stent surface does not cause a reaction in the human body. It should be quite resistant to corrosion. Must be strong enough to bear the pressure. Easy to manufacture.
  13. 13. Most stents are built on a stainless steel platform. But unfortunately, stainless steel is not fully compatible with the human body An alternative platform materials such as gold, titanium, cobalt- chromium alloy, and several types of polymer can also be used. Gold is biocompatible and usually inert, as well as highly visible. Cobalt-chromium has proven to be effective stent materials. Tantalum is a shiny, flexible, and highly radio-opaque though is more brittle than stainless steel, has proven to be quite resistant to corrosion. Certain polymers have found use as a stent materials. E.g. Silicone
  14. 14. DISAD.. If it gets stuck somewhere on the route, it is withdrawn a little and again pushed in. Not only it scratches the whole length of the arterial tubes of the body but it can also puncture any corner of the tubes. Stent surface after biodegradation can be very uneven and, as such, can induce various cells to adhere to the surface.