Histotripsy is a novel technology for non-invasive non-thermal mechanical (cavitational) tissue ablation that has been developed at the University of Michigan. Very intense ultrasound energy is generated by a transducer (Fig 1) and focused on a target point to generate microbubbles within the tissue. The energetic activity of these microbubbles then precisely breaks apart and destroys the targeted tissue (Fig 2 – This is a slide of kidney tissue. The left side shows normal appearing kidney tubules. The right side was within the targeted volume and all cells were destroyed with histotripsy treatment)
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We are performing pre-clinical experiments and designing instrumentation to apply histotripsy for treatment of:
- Benign Prostate Hyperplasia which affects 50% of all men producing urinary outflow obstruction and significant deterioration in quality of life. We are exploring histotripsy treatment delivered from outside the body to fractionate and destroy excess prostate tissue causing urinary obstruction. (video clip) (Fig 3. The picture on the left is a histological section of an untreated prostate. The urethra, seen in the center becomes blocked by excess tissue growth in BPH. A section of prostate after treatment with histotripsy is seen on the left. The urethra and central prostatic tissue was destroyed with histotripsy treatment and flushed out of the body leaving a wider urinary channel for improved urinary drainage.)
- Prostate cancer strikes 230,000 men annually in the United States. Existing treatments of radiation and surgery can result in damage to surrounding structures resulting in erectile dysfunction and urinary incontinence. Tissue destruction with histotripsy produces astonishingly sharp margins. We are developing methods to take advantage of this so that rather than surgery or radiation it may be possible to precisely ablate prostate tissue without producing collateral damage.
- Kidney cancer will be diagnosed in approximately 50,000 Americans this year. Many of these masses are being identified earlier when they are smaller and therefore amenable to less invasive therapies than in the past. Histotripsy is a potential therapy for these masses where energy delivered from outside the body is used to destroy the tumor and preserve normal kidney tissue – similar to the technique of shockwave lithotripsy for stone fragmentation.
Our goals at the Michigan Center for Minimally Invasive Urology are to continue development and application of this technology in collaboration with our colleagues in Biomedical Engineering. We feel this technology has the potential to transform the treatment of a wide array of malignant and benign diseases. (Fig 4).
See Also Therapeutic Ultrasound Group