How shockwave lithotripsy works

The basic idea

Extracorporeal shockwave lithotripsy — "extracorporeal" simply means "from outside the body" — uses focused acoustic shock waves aimed precisely at your stone. As the waves converge on the stone, the energy fractures it through a combination of direct pressure and tiny collapsing bubbles (cavitation) at the stone's surface. Over the session, a hard stone is reduced to sand-like fragments that your body can pass naturally in the urine.

Crucially, the waves are designed to pass harmlessly through soft tissue and release their energy only where they're focused — on the stone. That's what makes the procedure non-invasive.

How we target the stone

Precise aim is everything. We locate and continuously track the stone using imaging — X-ray (fluoroscopy), ultrasound, or both — so the focal point stays on the stone as you breathe and shift slightly. For certain stones that don't show up well on plain X-ray, such as uric acid stones, we use contrast or ultrasound to pinpoint them.

What the session is like

• Comfort. Treatment is typically done under IV sedation (monitored anesthesia care) — you're relaxed and comfortable, but general anesthesia usually isn't needed in the office setting.
• Duration. A session generally runs about 45–60 minutes.
• Going home. It's an outpatient procedure — most patients head home within an hour of finishing, with a prearranged ride.
• Afterward. Fragments pass over the following days to weeks. You may see some blood in the urine and feel mild flank soreness as they clear.