Cardiac Catheterization

WHAT YOU SHOULD KNOW ABOUT PERCUTANEOUS ANGIOPLASTY

Percutaneous transluminal coronary angioplasty (PTCA) is a nonsurgical procedure designed to widen or expand narrowed coronary arteries. First, the doctor inserts a plastic tube or catheter into the artery of the leg. He or she then advances the catheter into the aorta, which is the large artery that conducts blood from the heart to the rest of the body. It is then passed into the coronary arteries, which are the arteries that supply blood flow to the heart muscle itself. This procedure is monitored and guided by a special x-ray camera known as a fluoroscope and it is performed within the cardiac catheterization lab. Once the catheter (known as the guiding catheter) is passed into the origin of the narrowed coronary artery, a small, thin wire known as a guidewire is maneuvered fluoroscopically down the artery past the blockage. This serves as a track to allow passage of a balloon catheter mounted on the wire to pass through and across the blocked artery. The deflated balloon is then inflated, allowing it to compress the plaque and enlarge the diameter of the narrowed artery. Once the vessel is successfully dilated, the balloon is deflated and the balloon catheter is withdrawn. This increases the diameter of the vessel and improves blood flow. Unfortunately, the vessel can spontaneously contract shortly after the procedure (known as elastic recoil) and scar formation can occur over the ensuing weeks and months, both of which can reblock up the artery. To prevent the elastic contraction of the artery that occurs immediately and to lessen the chance of scar formation, typically a coronary stent is placed. This is done by mounting a stent, which is a small, latticed, stainless steel tube, on a balloon catheter. Similar to the balloon angioplasty technique, this catheter is advanced over the existing wire and through the guiding catheter and once it is across the area of previous blockage, the balloon is inflated, expanding the latticed, stainless steel tube and pushing it into the wall of the artery. This serves to buttress the artery, preventing any contraction and recoil. The balloon catheter wire and guiding catheter are then removed, resulting in a permanent superstructure buttressing and keeping the artery open.

PTCA is different from bypass surgery, in that bypass surgery provides a detour around the narrowed or blocked coronary artery using a length of vein from another part of the body. In PTCA and angioplasty, the obstructed part of the artery is widened, rather than bypassed. One of the drawbacks of angioplasty is its tendency towards restenosis. Restenosis is basically a scar formation within the dilated vessel. When the blood vessel is traumatized by the balloon and the stent, it reacts by forming a scar and typically, 20-25% of patients undergoing angioplasty will form a scar within the first six months, which can reblock up the artery. When a stent is placed, the restenosis likelihood is reduced to approximately 10-12%. If the artery were to reblock up, it occurs in a very slow manner and virtually never causes a heart attack. Importantly, the artery can be reopened with a combination of balloons, another stent, or different rotoablative techniques that chip away at the scar and reopen the vessel. In the vast majority of patients, the vessel can be kept open permanently. At Cardiac Specialists of Fairfield, we feel very strongly that angioplasty is a very serious and important procedure. Accordingly, we believe that the procedure should only be done by highly experienced operators. Unlike other groups in the area, in which all of the physicians do catheterization and angioplasty, at Cardiac Specialists, we have determined that it would be best performed high-volume operators. Accordingly, only three of our physicians, Dr. Driesman, Dr. Fishman, and Dr. Meizlish perform the interventional procedures. The American Heart Association and the American College of Cardiology suggest that an operator should do greater than 75 procedures a year to maintain competency. At Cardiac Specialists, all of our operators do between 200 and 300 procedures a year. This makes them some of the highest volume operators in New England and we believe, explains our extremely high success rate with a complication rate among the lowest in the region.