Improved imaging, tubeless PNL mark stone advances

Key Points

The past 2 decades have given urology some remarkable stone treatment technologies. Glenn M. Preminger, MD, professor of urologic surgery and director of the Comprehensive Kidney Stone Center at Duke University Medical Center, Durham, NC, suggests that the next decade might best be spent refining those technologies and determining which patients are likely to derive the greatest benefit from these advances.

Studies of kidney stone treatments being presented at the upcoming AUA annual meeting in Orlando, FL are moving in that direction. A few investigations are looking even further into the future to evaluate the impact of global warming on nephrolithiasis rates.

Among the studies noted by Dr. Preminger was one that identified the risks posed by supracostal percutaneous nephrolithotomy and others that examined the use of an advanced imaging technology to guide nephrostomy tract placement and reduce patients' exposure to radiation.

He noted that the use of advanced imaging also minimizes radiation.

"This is a hot-button issue. A number of studies suggest that total radiation exposure exceeding 20 millisieverts significantly increases the risk of malignancies," Dr. Preminger explained.

"Two studies to be presented during the 2008 AUA meeting further examine the impact of pre-treatment and follow-up imaging on radiation dosages. We may need to re-examine our use of imaging technologies for managing stone disease to limit the amount of radiation that patients receive."

"I believe we are still trying to define the ideal candidates for a tubeless approach and, more important, define those who should not be candidates for the this procedure. Most of the recent studies suggest that tubeless PNL procedures can be conducted on almost any patient, but I believe there are some in whom it might be safer to place a nephrostomy tube at the end of the case. Larger, multicenter, prospective trials are needed to better answer this question," Dr. Preminger said.

New devices, new techniques

Urologists attending the annual meeting will see clinical data from the next generation of intracorporeal lithotrites designed for percutaneous stone removal. These devices combine pneumatic and ultrasound technologies in a single instrument. The results of two newer-generation dual-energy devices will be presented.

"The point is that we are still making advances in our ability to target stones, remove them safely and quickly, and reduce patient morbidity," Dr. Preminger said.