Histotripsy for the Treatment of Uterine Leiomyomas: A Feasibility Study in Ex Vivo Uterine Fibroids.

Uterine fibroids (leiomyomas), the most common benign tumors in women of reproductive age, are a frequent cause of abnormal vaginal bleeding and other reproductive complaints among women. This study investigates the feasibility of using histotripsy, a non-invasive, non-thermal focused ultrasound ablation method, to ablate uterine fibroids. Human fibroid samples (n = 16) were harvested after hysterectomy or myomectomy procedures at Carilion Memorial Hospital. Histotripsy was applied to ex vivo fibroids in two sets of experiments using a 700-kHz clinical transducer to apply multicycle histotripsy pulses and a prototype 500-kHz transducer to apply single-cycle histotripsy pulses. Ultrasound imaging was used for real-time treatment monitoring, and post-treatment ablation was quantified histologically using hematoxylin and eosin and Masson trichrome stains. Results revealed that multicycle histotripsy generated diffuse cavitation in targeted fibroids, with minimal cellular ablative changes after treatment with 2000 pulses/point. Single-cycle pulsing generated well-confined bubble clouds with evidence of early coagulative necrosis on histological assessment in samples treated with 2000 pulses/point, near-complete ablation in samples treated with 4000 pulses/point and complete tissue destruction in samples treated with 10,000 pulses/point. This study illustrates that histotripsy is capable of fibroid ablation under certain pulsing parameters and warrants further investigation as an improved non-invasive ablation method for the treatment of leiomyomas.

Patient-predicted sleep position vs. HST data: a tendency to underestimate supine sleep.

PURPOSE: The purpose of this study is to measure people's accuracy when they estimate what proportion of their nightly sleep at home is supine vs. non-supine. METHODS: A series of patients referred for obstructive sleep apnea (OSA) evaluation were asked if they "knew with confidence" how they slept with regard to their body position. "Yes" responders were then asked to estimate what percentage of their sleep was supine vs. non-supine. This value was compared with the actual proportion of supine vs. non-supine sleep that they exhibited in a home sleep test (HST) that followed. RESULTS: We obtained data from 49 subjects who expressed that they "knew with confidence" how they sleep in terms of body position. Subjects in aggregate underestimated their proportion of supine sleep by 21.6% (p < .001). Thirty-nine subjects (80%) slept supine more in the HST whereas 8 (16%) slept supine less compared to their pre-test estimates. Using a common classification of OSA severity, 9 subjects (18%) demonstrated a more severe degree of OSA than would have occurred had they slept as they had predicted. CONCLUSIONS: Subjects in this study frequently underestimated their proportion of supine sleep compared to values measured in an HST. Because of the increased supine sleep they exhibited, the severity of their OSA was often greater in the test than it would have been had the subjects slept as they predicted. Sleep physicians should take into account the tendency of people to underestimate supine sleep. If patients with positional sleep apnea assert that they "always sleep laterally" when at home, they may be underestimating their true night-by-night OSA disease burden.