Catheterization is a cardiac test carried out to examine the blood flow through coronary arteries. The procedure helps cardiologists identify blockages in arteries, which can result in atherosclerosis, and study the functioning of valves. Catheterization is usually performed before a cardiac surgery to obtain a coronary angiogram or an X-ray image of the arteries. This angiogram makes it easy to determine the condition of a patient's heart and target problem areas during the surgery.
In the process of catheterization, patients are required to lie on a table, beneath an X-ray machine. The groin area, which is used for the insertion of catheter, is then anesthetized and an incision is made to access a blood vessel. This incision is used to insert the catheter or a thin tube that is threaded to the artery from the blood vessel. Throughout this process, doctors are guided by an imaging screen that displays the position and progress of the catheter in the body. Once it reaches the heart, the catheter is used to inject a special dye in the arteries. This dye is visible in the X-rays and assists cardiologists in taking a closer look at the blockages in heart.
Stenting is a process that follows catheterization during an angioplasty. It derives its name from a crimped mesh tube called stent that is placed in blocked and narrowed coronary arteries for their dilation which results in smooth flow of blood through them. During coronary stenting, a catheter with a deflated balloon at its tip is inserted through the incision into the blood vessel. The deflated balloon has a stent wrapped around it. Upon reaching the targeted artery, the catheter is used to inflate the balloon. While the balloon inflates and helps increase the space within the artery, the stent on the balloon expands and gets attached to the walls. When the stent is placed successfully, the balloon is deflated and the catheter is retrieved. The placement of a stent ensures that it will prevent the artery from getting narrowed or blocked again in future.
Patients suffering from coronary heart diseases and excessive cholesterol levels leading to blockage may find stenting very effective and significantly hassle free in comparison with complicated surgical procedures. Sometimes, stents are coated in medicines which are released into the heart to ease its functioning.
The duration of catheterization is not more than one hour, but stenting could take up to three hours, depending on the complexities of a case. There are a few rare complications that arise from catheterization and stenting, but these are observed in less than 2% patients who undergo the procedure. Such complications could be caused by an allergic reaction to the dye used in angiography, damage to blood vessels from the catheter and formation of blood clots post stenting. However, these problems are extremely uncommon and the high rate of success recorded in these procedures is evident throughout the world.