What is intravascular lithotripsy?
Over many years, calcium can build up in the wall of an artery and make it as hard as a pipe lined with limescale. Such an artery is difficult to open, and a stent placed into it may not expand properly. Intravascular lithotripsy uses the same principle as the machine that breaks up kidney stones: a balloon catheter containing tiny emitters is placed inside the narrowing and delivers pulses of sound energy. These shock waves pass harmlessly through the soft tissue but crack the hard calcium in the wall, so that the artery becomes flexible enough to be opened and stented properly.
Why is it done?
It is used when a coronary or leg artery is so heavily calcified that an ordinary balloon cannot open it or a stent will not expand fully. Treating a hard, calcified artery without preparing it is one of the main reasons stents fail later, so modifying the calcium first improves both the immediate result and the long-term outcome. Your cardiologist decides on lithotripsy from the appearance of the artery on the angiogram and, often, on intravascular ultrasound, sometimes choosing it instead of drilling the calcium away with a rotating burr.
What happens on the day?
Lithotripsy is done as part of an angiogram or stent procedure, in the catheterisation laboratory. You are awake but relaxed, with a drip in place, and the wrist or groin is numbed with local anaesthetic. A fine wire is passed across the narrowing, the lithotripsy balloon is positioned across the calcified segment and inflated gently, and then a series of pulses is delivered, usually in bursts of ten. You may hear a soft ticking sound and feel a mild fluttering or brief chest discomfort while the pulses are given. The artery is then dilated and a stent is normally placed and fully expanded. The extra step adds roughly ten to twenty minutes to the procedure.
What to expect afterwards
Aftercare is the same as for any stent procedure. If the wrist was used, a compression band stays on for a few hours; if the groin was used, you lie flat for a while. Most patients go home the same day or the next morning. Bruising at the puncture site is normal. You will need dual antiplatelet medication, usually aspirin plus a second tablet, for the period your cardiologist specifies, and it is very important not to stop these without advice, as that can cause the stent to block. Gentle activity can resume within a day or two, and heavy lifting after about a week.
Possible complications
Lithotripsy is well tolerated, but it forms part of a coronary intervention and carries those risks. Bruising or bleeding at the access site is the most common. During pulse delivery the heart rhythm may be briefly disturbed by extra or paced beats, which settles immediately afterwards. The artery can be torn or, rarely, perforated, requiring a covered stent or other treatment, and the vessel can go into spasm or develop a clot. Heart attack, stroke, kidney strain from the contrast dye and, very rarely, death are the serious risks shared with all coronary procedures. Your cardiologist will explain your personal risk before you consent.
This information does not replace a consultation. Please discuss your own risks and options with your cardiologist.