Before the actual procedure, various preliminary examinations are necessary to assess the number, extent and position of the constrictions as well as the risk factors. These include ECG and exercise ECG, blood tests and an X-ray of the chest to assess the heart and lungs. Due to the administered contrast media, special attention is paid to the question of an existing allergy, hyperthyroidism or renal insufficiency. The patient must be fasted for examination.
How does the PTCA work?
PTCA is performed under local anesthesia and some patients are given sedatives. On the arm we put an entrance in the vein, over which during the treatment possibly medicaments and liquid can be administered. Usually, the tube is inserted on the right groin - this is why shaved. Rarely does access via the left groin or an artery in the elbow bend.
Inserting the hollow needle
After the skin has been anesthetized and disinfected at the appropriate place, a hollow needle is introduced into an artery, and over this a 2 mm thick and 10 cm long plastic tube with non-return valve (sluice). The guiding catheter - a tube with a fine guidewire - is placed over it and slowly advanced to the heart under X-ray control. Since the vessels have no nerves from the inside, the patient feels nothing of it.
Threading the balloon catheter
If the tip of this guide catheter in the coronary vessel, the wire is removed and threaded through the catheter lying back, the actual, about 1 mm thick balloon catheter. This also runs on a fine wire with a soft, slightly curved tip, with the help of the catheter can be turned from the outside and turned so that the still folded balloon can be positioned exactly at the desired location. The location of the cardiac catheter is constantly monitored by introducing small amounts of contrast agent and examining its distribution by X-ray.
Stretching the balloon
At the pathologically narrowed area, the balloon, which is about 2 cm long, is inflated by means of contrast medium and possibly saline solution and reaches a precisely defined diameter (2-4 mm). The pressure is usually maintained for 10-30 seconds, in some cases up to 1 minute or longer. During inflation, the patient usually feels a feeling of pressure in the chest - similar to an angina pectoris attack, but usually less violent.
Remove the catheter
These symptoms arise when the blood supply is temporarily interrupted during expansion. Such complaints must be reported to the doctor and usually show up by appropriate ECG changes. If necessary, the doctor will interrupt the treatment until the symptoms have resolved and the ECG findings have returned to normal - usually within a few seconds of completing the stretching process. If X-ray inspection indicates successful dilation without tearing, the catheter is removed. In some cases / centers, the lock will be left in place for any necessary re-expansion until the next day.
Support by stent
In many cases, immediately after the distension of the narrowed vessel, a stent is inserted there - a small tube or wire mesh, which supports the vessel from the inside and keeps it open. In recent years, drug-coated stents have been used frequently, which slowly deliver an active ingredient, which offer significantly improved protection against re-stenosis (restenosis).
However, it has been shown that with such stents in certain patients, the risk of later, life-threatening blood clot formation increases and these often grow worse. In a new method that aims to avoid these disadvantages, an untreated stent is used and this then soaked by catheter drug.
What happens after that?
When the procedure is successfully completed, the patient is transferred to the intensive care or monitoring ward and continuously connected to an ECG device. The person concerned has to observe bed rest for about 10 hours. To prevent thrombosis, he receives anticoagulant drugs as an infusion. For the contrast agent to be excreted via the kidneys, the patient must drink a lot.
After removing the lock, a pressure bandage is applied to the access point for about 12-24 hours. Once removed, the patient may get up again but should not lift and carry for a few days. Usually, a short inpatient stay over 2 days is scheduled for the entire procedure including subsequent monitoring.