Before the actual procedure, several preliminary tests are needed to assess the number, extent, and location of the narrowings, as well as risk factors. These include ECG and exercise ECG, blood tests, and a chest x-ray to evaluate the heart and lungs. Special attention is paid to the question of an existing allergy, hyperthyroidism or kidney weakness due to the contrast agents administered. The patient must be fasting for the examination.
What is the procedure for PTCA?
PTCA is performed under local anesthesia, and some patients are given a sedative. An access tube is placed in the vein on the arm, which can be used to administer medications and fluids during the procedure, if necessary. Usually, the tube is inserted at the right groin – this is therefore shaved. Less commonly, access is made through the left groin or an artery in the arm in the crook of the arm. Insertion of the hollow needle
After the skin at the corresponding site has been anesthetized and disinfected, a hollow needle is inserted into an artery and a plastic tube with a non-return valve (sluice) is inserted through the needle, which is about 2 mm thick and 10 cm long. The so-called guide catheter – a tube with a fine guide wire – is inserted over this and slowly advanced to the heart under X-ray control. Since the vessels do not have any nerves on the inside, the patient does not feel anything. Threading the balloon catheter
Once the tip of this guide catheter is in the coronary vessel, the wire is removed and the actual balloon catheter, which is about 1 mm thick, is threaded through the lying catheter. This also runs over a fine wire with a soft, slightly curved tip, with the help of which the catheter can be twisted and turned from the outside and thus the balloon, which is still folded up, can be positioned exactly at the desired location. The position of the cardiac catheter is continuously monitored by introducing small amounts of contrast medium and checking its distribution by means of X-rays. Dilation of the balloon
At the pathologically narrowed site, the balloon, which is about 2 cm long, is inflated using contrast medium and possibly saline solution, reaching a precisely defined diameter (2-4 mm). The pressure is usually maintained for 10-30 seconds, in individual cases up to 1 minute or longer. During inflation, the patient usually feels a pressure sensation in the chest – similar to an angina pectoris attack, but usually less severe. Removing the catheter
These symptoms are caused by the fact that the blood supply is interrupted for a short time during inflation. Such symptoms must be reported to the physician and are usually indicated by corresponding ECG changes. If necessary, the physician will interrupt the treatment until the discomfort has subsided and the ECG findings have normalized – usually within a few seconds after completion of the stretching process. If X-ray monitoring indicates successful dilatation without tearing, the catheter is removed again. In some cases/centers, the sheath is left in place until the next day for re-expansion if necessary.
Stent support
In many cases, immediately after the narrowed vessel is dilated, a vascular support (stent) is placed there – a small tube or wire mesh that supports the vessel from the inside and keeps it open. In recent years, drug-eluting stents, which slowly release a drug that provides significantly improved protection against re-narrowing (restenosis), have been widely used. However, such stents have been shown to increase the risk of subsequent, life-threatening blood clot formation in certain patients and often have poorer ingrowth. A new procedure that aims to avoid these disadvantages involves inserting an untreated stent and then soaking it with a drug via catheter.
What happens afterward?
Once the procedure is successfully completed, the patient is transferred to an intensive care or monitoring unit, where he or she is continuously connected to an ECG machine. The patient must remain on bed rest for about 10 hours. To prevent thrombosis, he receives anticoagulant medication as an infusion. In order for the contrast medium to be excreted via the kidneys, the patient must drink plenty of fluids. After removal of the sheath, a pressure dressing is applied to the access site for approximately 12-24 hours. Once this is removed, the patient is allowed to get up again, but should not lift or carry heavy loads for a few days.Usually, a short inpatient stay of 2 days is scheduled for the entire procedure, including subsequent monitoring.
