The SpermVD^℗ - A Novel Solution for Cryopreservation of Rare Spermatozoa.

Introduction:

Cryopreservation of a small number of human spermatozoa can provide an appropriate solution in cases of severe male infertility. As existing technologies for cryopreservation of spermatozoa are unsuitable in cases of extremely low numbers of spermatozoa, a need for finding a solution has arisen. Here we report a development of an ad hoc designed device - SpermVD^℗, as a platform for a simple and efficient method for cryopreservation of rare spermatozoa.

Aim: The aim of the study was to test whether the novel SpermVD^℗ storage device is an efficient tool of cryopreserving small numbers of spermatozoa.

Materials and methods:

Sperm was collected from patients diagnosed with virtual azoospermia. After centrifugation and washing the re-suspended pellet was distributed into 10μL droplets on a Petri dish. The droplets were searched and any single spermatozoon found was transferred to droplets of 1μL of washing medium/cryoprotectant 50/50 v/v mixture on the SpermVD^℗. The SpermVD^℗ was then plunged into LN ². At oocyte pick-up day, the SpermVD^℗ was thawed and placed on an ICSI dish. Spermatozoa were retrieved from the droplets and used for ICSI.

Main results and the role of chance:

* Linear regression was used for continuous variables and logistic regression was used for categorical variables. No correlation was found between motility of thawed spematozoa and fertilization rate (p=0.661) and pregnancy rate (p=0.083).

Conclusions:

SpermVD is a convenient means of storage and retrieval of small numbers of spermatozoa. It may reduce the need for further surgical intervention by allowing storage of any excess spermatozoa left after ICSI and makes extended search of the ejaculate prior to OPU day a viable substitute for surgical sperm retrieval.