Ultrastructural evaluation of human metaphase II oocytes after vitrification: closed versus open devices.
OBJECTIVE
To compare the ultrastructural appearance of oocytes after vitrification and warming with two different devices.


METHODS
Oocytes were examined by ultrastructural analysis after vitrification and warming with use of closed (CryoTip; Irvine Scientific, Santa Ana, CA) or open (Cryotop; Kitazato BioPharma Co., Ltd., Shizuoka, Japan) devices.


METHODS
Pordenone Hospital IVF Unit and Medical Morphological Research Department, University of Udine.


METHODS
Surplus oocytes from 10 patients (aged 31-39 years) undergoing assisted reproductive technologies at the Pathophysiology Unit of Human Reproduction and Sperm Bank between 2006 and 2008.


METHODS
Oocytes with normal invertoscopic appearance underwent vitrification and warming with closed (CryoTip) or open (Cryotop) devices and were processed for transmission electron microscopy.


METHODS
Cryodamage extent and cell alterations in oocytes after open or closed vitrification and warming procedures and their rehydration rate.


RESULTS
A higher rate of complete oocyte rehydration and less-severe ultrastructural alterations were observed after vitrification and warming with the open Cryotop device.


CONCLUSIONS
These preliminary data suggest that oocyte ultrastructure is better preserved with an open rather than closed vitrification and warming protocol.
Bonetti
Antonella
A
Department of Medical Morphological Research, Medical School, University of Udine, Udine, Italy.
Cervi
Marta
M
Tomei
Francesco
F
Marchini
Maurizio
M
Ortolani
Fulvia
F
Manno
Massimo
M
D000328:Adult; D002470:Cell Survival; D015925:Cryopreservation / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008677:Metaphase; D046529:Microscopy, Electron, Transmission; D009865:Oocytes / Q000648:ultrastructure*; D010062:Ovulation Induction; D027724:Reproductive Techniques, Assisted; D058989:Vitrification