Burst of Ultrasound Waves Can Break up Kidney Stones in 10 minutes

A small study shows that ultrasound bursts reduce kidney stones‘ volume by 90%, according to research published this week in the Journal of Urology.

Using burst wave lithotripsy (BWL), UW Medicine urologists were able to fragment the stones in 10-minute procedures on patients who were under anesthesia. Eventually, urologists could use this procedure on conscious patients in a clinic visit, said Dr. Mathew Sorensen, a study co-author. Kidney stones are common, affecting 1 in 10 Americans at a cost of $10 billion per year to treat, the report said.  While many stones pass on their own, treatments are sometimes needed to help expel them.

Every year, more than 600 people in the throes of kidney-stone pain seek emergency care at Harborview and UW Medical Center (University of Washington)  in Seattle. Kidney stones that become stuck in the urinary tract can cause debilitating pain: The obstruction of urine flow also can result in kidney swelling and cramping and set the stage for infection or lasting damage. Many stones can be treated with a technique called extracorporeal shock wave lithotripsy (ESWL) where sound waves are used to break the stone so that the fragments would be more likely to pass. In some cases, however, ESWL only fractures the stones rather than pulverizing them, Sorensen said.  Ureteroscopy is another minimally invasive way to treat stones but often requires a temporary stent, which can be quite uncomfortable.

The ways we have to currently treat stones have some downsides,” he said. “Most involve anesthesia.”

In contrast to the shock waves used in ESWL, the BWL procedure uses “short harmonic bursts” of ultrasound energy, potentially enabling the stones to be broken up in a shorter procedure without the need for sedation or anesthesia. Pre-clinical studies supported the effectiveness of BWL in breaking experimental stones of varying size and composition, the study noted.

In this study, Sorensen and urology colleague Dr. Jonathan Harper, the study’s lead author, performed initial studies in human patients with kidney stones. The patients were undergoing ureteroscopy, which is used to treat larger stones. Before that treatment, the stones were treated with BWL for no longer than 10 minutes. Using the ureteroscope, the researchers were able to directly observe how well the ultrasound waves worked to break the stones, as well as observe any injury to the kidney tissues.

Source: https://newsroom.uw.edu/

VR Gives 3D Depiction Inside Blood Vessels

UW Medicine interventional radiologist Wayne Monsky first saw virtual reality’s vivid, 3D depiction of the inside of a phantom patient’s blood vessels, his jaw dropped in childlike wonder.

A virtual-reality depiction of a catheter navigating blood vessel. With a VR headset, this would be 3D (click on the image to enjoy video)

When you put the (VR) headset on … you have a giddy laugh that you can’t control – just sheer happiness and enthusiasm. (I’m) moving up to the mesenteric artery and I can’t believe what I’m seeing,” he recalled.

The experience reminds him of “Fantastic Voyage,” the ’60s-era sci-fi film about a submarine and crew that are miniaturized and injected into a scientist’s body to repair a blood clot.

As a child, and today, I’ve been amazed at the premise that one day you can swim around inside someone’s body. And really, that’s the sensation: You’re in it,” he said. Interventional radiologists use catheters, thin flexible tubes that are inserted into arteries and veins and steered to any organ in the body, guided by X-ray visuals. With this approach, they (and cardiologists, vascular surgeons, and neuro-interventionalists) treat an array of conditions: liver tumors, narrowed and bleeding arteries, uterine fibroids, and more.

Monsky and two collaborators have pioneered VR technology that puts the operator inside 3D blood vessels. By following an anatomically correct, dynamic, 3D map of a phantom patient’s vessels, Monsky navigates the catheter through junctions and angles. The catheter‘s tip is equipped with sensors that visually represent its exact location to the VR headset. It’s a sizable leap forward from the 2D, black-and-white X-ray perspective that has guided Monsky’s catheters through vessels for most of his career.

He recently presented study findings that underscore VR’s value: In tests of a phantom patient, VR guidance got him to the destination faster – about 40 seconds faster, on average, over 18 simulations – than was the case with X-ray guidance.

Source: https://newsroom.uw.edu/