Schiewe Mitchel C, Zozula Shane, Nugent Nancy, Waggoner Kelley, Borba Jessica, Gamboa Lisa, Whitney John B
Ovation Fertility;
Ovation Fertility.
J Vis Exp. 2017 Mar 2(121):54871. doi: 10.3791/54871.
Clinical embryo vitrification evolved with the development of unique vitrification devices in the 21 century and with the misconception that ultra-rapid cooling in an "open" system (i.e., direct LN2 contact) was a necessity to optimize vitrification success. The dogma surrounding the importance of cooling rates led to unsafe practices subject to technical variation and to the creation of vitrification devices that disregarded important quality-control factors (e.g., ease of use, repeatability, reliability, labeling security, and storage safety). Understanding the quality-control flaws of other devices allowed for the development of a safe, secure, repeatable, and reliable µS-VTF method aimed to minimize intra- and inter-technician variation. Equally important, it combined the availability of two existing FDA-compliant devices: 1) a 0.3-mL ionomeric resin embryo straw with internalized, dual-colored, tamper-proof labeling with repeatable weld seal potential; and 2) shortened, commonly-used, 300-µm ID sterile flexipettes to directly load the embryo(s) in order to create a highly-effective global vitrification device. Like other aseptic, closed vitrification systems (e.g., High Security Vitrification (HSV), Rapid-i, and VitriSafe) effectively used in reproductive medicine, microSecure Vitrification (µS-VTF) has proven that it can achieve high post-warming survival and pregnancy outcomes with its attention to simplicity, and reduced technical variation. Although the 0.3-mL embryo straw containing an internal hydrophobic plug was commercially replaced with a standard semen straw possessing cotton-polyvinyl pyrrolidone (PVP) plugs, it maintained its ionomeric resin composition to ensure weld sealing. However, the cotton plugs can wick out the fluid-embryo contents of the flexipettes upon contact. A modified µS-VTF method was adapted to include an additional internal weld seal before the plug on the device loading side. The added technical step to the µS-VTF procedure has not affected its successful application, as high survival rates (> 95%) and pregnancy rates continue today.
临床胚胎玻璃化冷冻技术是随着21世纪独特玻璃化冷冻设备的发展以及一种误解而演变而来的，这种误解认为在“开放”系统（即直接接触液氮）中进行超快速冷却对于优化玻璃化冷冻的成功率是必要的。围绕冷却速率重要性的教条导致了不安全的操作，这些操作容易受到技术差异的影响，并且催生了一些忽视重要质量控制因素（如易用性、可重复性、可靠性、标签安全性和储存安全性）的玻璃化冷冻设备。了解其他设备的质量控制缺陷后，开发出了一种安全、可靠、可重复且稳定的微安全玻璃化冷冻（µS-VTF）方法，旨在最大程度减少技术人员内部和之间的差异。同样重要的是，它结合了两种现有的符合美国食品药品监督管理局（FDA）标准的设备：1）一支0.3毫升的离聚物树脂胚胎吸管，带有内置的双色防篡改标签，具有可重复焊接密封的潜力；2）缩短的、常用的内径为300微米的无菌柔性移液管，用于直接装载胚胎，从而创建一种高效的整体玻璃化冷冻设备。与生殖医学中有效使用的其他无菌、封闭玻璃化冷冻系统（如高安全性玻璃化冷冻（HSV）、Rapid-i和VitriSafe）一样，微安全玻璃化冷冻（µS-VTF）已证明，通过注重简单性和减少技术差异，它可以实现较高的复温后存活率和妊娠结局。尽管含有内部疏水塞的0.3毫升胚胎吸管已在商业上被具有棉-聚乙烯吡咯烷酮（PVP）塞的标准精液吸管所取代，但它仍保持其离聚物树脂成分以确保焊接密封。然而，棉塞在接触时会吸走柔性移液管中的胚胎液体内容物。一种改良的µS-VTF方法进行了调整，在设备装载侧的塞子之前增加了一个额外的内部焊接密封。µS-VTF程序中增加的这一技术步骤并未影响其成功应用，因为如今仍保持着较高的存活率（>95%）和妊娠率。
