AUA 2009 - Stone Disease: Research/New Technology - Improving The Efficiency Of Stone Fragment Removal: Use Of Iron-Oxide Microparticles To Allow Stone Extraction With Novel Magnetic Tools - Session Highlights

CHICAGO, IL, USA ( - In this very interesting idea for removal of stone fragments during endourological procedures, Dr. Chad Tracy and associates have developed an iron-oxide microparticle that can attach to calcium stones and cause them to become paramagnetic. The fragments are then attracted to a prototype magnetic device and can be removed easily. In this initial report, human stone fragments were exposed for 2 hours to a solution that contained the custom protein linked iron microparticle. The particles are attracted to calcium and should not bind to urothelium. The stones were then placed into an artificial bladder and then the time to remove the stones with the prototype magnetic device versus a standard 2.4 French stone basket was compared.

In seven trials, the time to remove the stones with the magnetic device was 47% less than with the stone basket. The magnet was able to remove up to 10 stones at once, while the basket could never remove more than one stone at a time.

While this is a preliminary study, and the current two hour incubation period is too long for current clinical use, in the future this may be something that is added to the irrigant during endourological procedures, and help to both reduce operative time and improve stone free rates.

Presented by Chad R. Tracy, MD, et al. at the Annual Meeting of the American Urological Association (AUA) - April 25 - 30, 2009 - McCormick Place Convention Center - Chicago, Illinois, USA.

The opinions expressed in this article are those of the Contributing Medical Editor and do not necessarily reflect the viewpoints of the American Urological Association. Full AUA Conference Coverage