In vitro mitral chordal cutting by high intensity focused ultrasound
In vitro mitral chordal cutting by high intensity focused ultrasound
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DOI：
10.1016/j.ultrasmedbio.2007.09.003
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发表时间：
2008-03-01
影响因子：
2.9
通讯作者：
Homma, Shunichi
中科院分区：
文献类型：
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作者：
Abe, Yukio;Otsuka, Ryo;Homma, Shunichi
二尖瓣返流，当它由二尖瓣瓣叶关闭的功能限制引起时，可以通过手术切除二尖瓣腱索来缓解。我们假设，高强度聚焦超声（HIFU）可能是一种有用的非侵入性体外技术切割二尖瓣腱索。作为一个试点研究，以测试这一假设，我们研究了在体外的可行性，使用高强度聚焦超声切割小牛二尖瓣腱索的直径从0.2至1.6毫米。百分之六十七的腱索被完全切断与高强度聚焦超声，在4.67 MHz和45 W的声功率，高达120个脉冲的0.3秒的持续时间在2秒的间隔。当脉冲持续时间减少到0.2 s时，45%被完全切断。完全切割的腱索的平均直径明显小于未完全切割的腱索（0.59 ± 0.30对1.14 ± 0.30 mm，脉冲持续时间为0.2 s，p < 0.0001; 0.68 +/- 0.29对比1.32 +/- 0.20 mm，脉冲持续时间为0.3 s，p < 0.0001）。对于每个脉冲持续时间，完全切割所需的脉冲数与腱索直径呈强正相关。总之，体外HIFU切割二尖瓣腱索的可行性取决于腱索直径，但可通过HIFU设置进行控制。
Mitral regurgitation, when it arises from functional restriction of mitral leaflet closure, can be relieved by surgical cutting of the mitral tendineae chordae. We hypothesized that high intensity focused ultrasound (HIFU) might be useful as a noninvasive extracorporeal technique for cutting mitral chordae. As a pilot study to test this hypothesis, we examined the in vitro feasibility of using HIFU to cut calf mitral chordae with diameters from 0.2 to 1.6 mm. Sixty-seven percent of chordae were completely cut with HIFU, operated at 4.67 MHz and 45 W acoustic power, with up to 120 pulses of 0.3-s duration at 2-s intervals. Forty-five percent were completely cut when the pulse duration was reduced to 0.2 s. The average diameter of those chordae, which were completely cut, was significantly smaller than that of incompletely cut chordae (0.59 +/- 0.30 versus 1.14 +/- 0.30 nun with a pulse duration of 0.2 s,p < 0.0001; 0.68 +/- 0.29 versus 1.32 +/- 0.20 mm with a pulse duration of 0.3 s,p < 0.0001). For each pulse duration, the number of pulses required for complete cutting exhibited a strong positive correlation with the chordae diameter. In conclusion, in vitro feasibility of mitral chordal cutting by HIFU depended on the diameter of chordae but was controllable by HIFU settings.