Cardiac catheterization (coronarography)/ Angioplasty
Cardiac catheterization (coronarography) is a diagnosis procedure for patients with cardiac diseases or suspicion of cardiac disease, presenting chest pain or chocking sensation at effort or at rest. The procedure is carried out with the patient fasting, conscious but slightly sedated, lying down. The physician applies regional anaesthesia at the level of skin in the area where he performs the puncture (groin or arm level). The catheter is inserted through a vein or artery up to the cardiac level. This catheter is similar to a slender, thin, flexible tube, having 2mm in diameter and is handled using radioscopy. On this catheter there is inserted the contrast substance in order to make visible, under X-rays, the blood vessels or the cavities of the heart, the images being registered and projected on a screen, during the procedure.
The procedure evidences the narrowing or blocking location of the coronary arteries, the ones responsible for the chest pain. During the cardiac catheterization the blocked coronary artery may be opened by performing another procedure called angioplasty. Most patients who have suffered a myocardial infarction show partially or totally blocked coronary arteries. The procedure shows us if the affected arteries may be treated by angioplasty or heart surgery.
Cardiac catheterization also supplies data about the heart’s anatomy, the interior aspect of the heart’s cavities, the functioning of the cardiac valves. For this also being determined the O2 pressure and saturation within the cardiac cavities and blood vessels.
Balloon percutaneous angioplasty (PTCA = Percutaneous Coronary Angioplasty) is a therapeutic medical procedure, minimally invasive, which reestablishes the normal blood flow at the level of the heart’s muscle through a narrowed or blocked coronary artery. This procedure involves the insertion, through puncture - usually - at the level of the femoral artery - of a slender, flexible tube (catheter) which is fitted at one end with a balloon. The balloon is pushed up to the location of the vessel narrowing, at which point it is inflated in order to increase the artery‘s diameter. The simple dilatation of the stenosis implies only the inflating and deflating of the balloon, however this procedure has to be repeated often.
Percutaneous angioplasty using bare metal stent: a better variant for maintaining the stable blood flow is placing a stent on the stenosed portion of the vessel. Upon insertion the balloon + stent system is folded and in this condition has a diameter of <1mm. The stent is a laced metal tube which is unfolded (opened) by inflating the balloon on which it is attached and which remains in the vessel after the balloon’s extraction. The stent is selected so that it traverses the arteries and the injury which will have applied a prosthesis, it maintains the initial form of the vessel as well as the optimal diameter for a period as longer as possible. Depending on the diameter of the prosthetic vessel, on the length of the injury and on other risk factors such as diabetes, in 20-30% of the cases new narrowings appear, with time, in the stent (intrastent restenosis).
Percutaneous angioplasty using drug-eluting stent which stops and prevents in-stent restenosis: the procedure is the same as in the case of percutaneous angioplasty using bare metal stent, only that in this case the sent is a material specially impregnated with a pharmaceutical substance which intercedes at cellular level and prevents the occurrence of the neointimal hyperplasia phenomenon (increase of the interior stratum which lines the vessel). This substance inhibits the neointimal hyperplasia phenomenon and allows the stent to be integrated in the vessel’s wall (injury healing), without onset - except for rare cases - of the in-stent restenosis. This type of special stent is called "Drug Eluting Stent"^top^