The current "gold standard" treatment is a procedure called a trans-urethral resection of the prostate, in which an instrument with rotating blades is inserted through the penis. That instrument can be used to scrape away enough prostate tissue to allow urine to flow normally.
"It's like a mini Roto-Rooter device," said Peter Kaczkowski, a senior engineer at the University of Washington's Applied Physics Laboratory who was not part of Roberts's team.
But complications are common, ranging from bleeding to incontinence to lack of sexual function.
"It's also fairly painful and clearly unpleasant," Kaczkowski said.
What's more, the mortality rate can be as high as one percent—"exceedingly high, given that this is a benign condition," study author Roberts said.
The team discovered that not only could they sculpt well-defined holes into the dogs' prostates, but that the procedure caused the dogs no discomfort.
"Very surprisingly, there was only a very minimal amount of bleeding," said Roberts, who presented his research in May at the Acoustical Society of America meeting in Portland, Oregon.
"It looks very promising."
University of Washington's Kaczkowski agreed.
"If this pans out, everybody will be treating [enlarged prostates] this way," he said.
Kaczkowski compares it to replacing the surgically invasive method with something more like pressure washing.
"A pressure washer is innately more benign than rotating blades," he said.
In the long run, the technique may also help men with prostate cancer. "There's a wide-open range of targets," Roberts said.
But first scientists have to make sure that the ultrasound pulses don't create byproducts that promote metastasis, or the spread of cancer cells throughout the body.
"We're studying this now," Roberts said.
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