Quality Control Factors Influencing the Successful and Reliable Implementation of Oocyte and Embryo Vitrification

Abstract

Clinical vitriication evolved slowly, with interests and acceptance being commercially driven by the development of unique devices, safer solutions, and the misconception that ultra-rapid cooling in an open system was a necessity to optimizing vitriication success. Furthermore, the dogma surrounding the importance of cooling rates has led to unsafe practices subject to excessive technical variation and risky modiications to create closed-storage devices. The aim of this chapter is to highlight important quality control factors e.g., ease of use, repeatability, reliability, labeling security, and cryostorage safety) into the selection process of which device/solution to use, independent of commercial manipulations. In addition, we provide clinical and experimental evidence in support of warming rates being the most important factor determining vitriication survival. Lastly, we exhibit indisputable support that aseptic, closed vitriication systems, speciically microSecure vitriication μS-VTF), can achieve success with atention to quality control details often lacking in open vitriication devices.Keywords: blastocyst, cryopreservation, device type, oocyte, quality control, vitriication . IntroductionThe early successes of William F. Rall, PhD, and coworkers with mammalian embryo vitriication VTF) were based on extensive experimentation, meticulous solution and strawhandling preparations, and precise straw sealing [ , ]. "lthough there was less overt cellular © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.damage, these early investigations simply proved that vitriication was a potentially efective alternative cryopreservation procedure, but not necessarily more efective than conventional slow-freezing methodologies. The degeneration experienced with visually intact vitriied embryos could have been due to the potential cryotoxicity of high-molarity vitriication solutions e.g., VS a = . M glycerol) [ ]. "n alternative consideration involved the importance of warming rates to prevent recrystallization events that could adversely efect cellular survival of vitriied blastomeres [ ]. In the early to mids, most investigations focused on developing safer, less toxic solutions [ -] to improve vitriication success. It was widely accepted that the combined use of less concentrated permeating cryoprotective agents CP"s) made for safer vitriication solutions [ ]. Indeed, by combining permeating CP"s e.g., dimethyl sulfoxide DMSO), ethylene glycol EG), and glycerol GLYC)), and adding ot...

Modified MicroSecure Vitrification: A Safe, Simple and Highly Effective Cryopreservation Procedure for Human Blastocysts

“…To a great extent, this was due to the development of specialized vitrification devices. Some of these devices have handicapped the overall safety, efficiency and effectiveness of clinical vitrification by introducing inherent design flaws to devices used in the IVF industry 11 . Indeed, the nuances of different devices introduce significant technical variation between programs, commonly referred to as "technical signatures" 12 .…”

Vitrification: Fundamental Principles and Its Application for Cryopreservation of Human Reproductive Cells

“…When contemplating which vitrification device to use, there are some critical factors to evaluate to accurately judge its potential usefulness [57]. We believe it is important to assess labeling potential, technical ease, simplicity and repeatability, LN 2 storage, recovery potential, and survivability.…”

Vitrification: the pioneering past to current trends and perspectives of cryopreserving human embryos, gametes and reproductive tissue

“…67 What can be performed to minimize intra-and inter-laboratory procedural variation beyond the essential need for training? Numerous risk factors and safety issues associated with different vitrification methods should be considered (eg, LN 2 device handling; device design flaws; shipment concerns and viral cross-contamination of semen, embryos or ova), 25,36,40,[67][68][69] but are not reviewed in this article. In essence, there are basic quality control (QC) factors warranting implementation to make vitrification a consistent, efficient, reliable and highly effective ART procedure that minimize liability and maximize success.…”

“…The reality is that highly qualified embryologists and experienced laboratories warming vitrified specimens are vulnerable to the procedural QC habits (good and bad) and device choices (open, closed or hybrid systems) used by other ART laboratories and their staff. 67 Failure to identify eggs can be particularly problematic in devices that do not allow direct visualization of the eggs on or in the device, because they can become highly translucent in 1.0 M sucrose solutions (ie, T1) immediately postwarming/elution. Unfortunately, most published reports simply hide their recovery failures in their otherwise good overall survival rates.…”

“…Recovery rates should not be minimized, as they represent a potential design flaw to a device and create a serious liability risk to the group who ultimately discovers a problem with this issue. 67 Obviously, training and experience are critical to reducing technical variation and insuring reliable consistent outcomes.…”