Androlog Mail:
Re: Poor results with frozen epididymal sperm
We were somewhat hesitant to use intentionally cryopreserved epididymal sperm
because we did not believe it would provide competitive results when
compared with fresh epididymal sperm. I have to admit we were wrong. In
our first ten cycles since July of 1998 our ongoing clinical pregnancy rate
is 60%. Currently we are only using frozen epididymal sperm because of the
convenience in scheduling, the guarantee that sperm will be available at the
time of egg retrieval and I can now take the time to get as much sperm as
possible.
At the time of retrieval I use an operating microscope and believe this is
essential to finding the best tubules especially in men who have had a
vasectomy or failed vasovasostomy. I aspirate into 0.1cc of HTF using a 1cc
tuberculin syringe and a 30 gauge blunt tip opthalmic needle. The specimens
are immediately analyzed in the OR using a microscope and microcell counting
chamber. I continue the aspiration until approximately 10 million motile
sperm are obtained. This usually is a raw number of 100-200 million sperm
with motility ranging from 5-10%. The specimens are taken back to the lab
and centrifuged over a 55-80-90% gradient of Pure Sperm. The pellet is
resuspended in HTF with 10% serum and washed three times at 300g for 5 min.
The pellet is then resuspended in 500ul of HTF and counted. An equal volume
of test yolk buffer is added and the specimen divided into the volume that
will yield 1 million motile sperm. We usually end up with 4-6 vials.
These are then frozen at a controlled rate. 22C to 5C at 7 degrees/min,
then 5C to (-7C) at 5C/min, then hold for 5 min, at (-7C) then (-7C) to
(-100C) at 10C/min, then plunge in liquid nitrogen. For thawing the
specimen is placed in a water bath at room temperature for 30 minutes washed
then place under oil for micromanipulation.
Michael A Witt MD
Reproductive Biology Associates
5505 Peachtree Dunwoody Rd
Suite 550
Atlanta, GA 30342
404 256 6987
mwittmd@mindspring.com
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