Microsurgical Epididymal Sperm Aspiration (MESA) is performed when there is a blockage to sperm flow that cannot be corrected. Having one of the world’s largest experiences in this procedure, I extract sperm from outside the testis, freeze it at one of the many IVF groups I work with, and they use it later as a source of sperm for a cycle of ICSI. The pregnancy rate is excellent. I authored the first papers on intentionally freezing the sperm, now a commonly used approach in the top IVF centers.

1. Robert D Oates, M.D.
Boston Medical Center

2. *
*Also known as MESA
*MESA is a procedure to harvest sperm from the epididymis
*The sperm are made in the testis and travel first into
the epididymis
*The epididymis then turns into the vas deferens which
brings the sperm up and out of the scrotum
*If there is a blockage somewhere in this system, sperm
may be able to be surgically retrieved from the epididymis

3. *
*MESA can be used whenever it is possible to harvest sperm
from outside the testicle, somewhere in a fully formed or
only partially formed epididymis.
An unreconstructable blockage of the system
Sperm production must be normal
It is not used when sperm production is deficient
*In CBAVD and CF (see Genetics Presentation)
Most common reason in my practice for MESA

4. Male Reproductive Anatomy: Distal Ductal System
VD
SV
ED
VD: vas deferens – brings the sperm
up and out of the scrotum
SV: seminal vesicle – makes most of
the fluid found in the ejaculate
ED: ejaculatory duct – the tube that
comes through the prostate with
the fluid from the VA and SV
In CBAVD, the VA and the SV are not
present and so sperm cannot make
its way up from the testes. Without
the SV, the volume of the ejaculate
Is quite low.

5. * Congenital Bilateral Absence of the Vas Deferens
(CBAVD)
*No vasa can be felt on scrotal exam
*There is always a little bit of the epididymis
* May be just the caput (the top part)
*Testes normal size (sperm production is fine)
*Low volume semen analysis
Testis
Caput

6. http://www.hopkins-genomics.org/cf/cf_research.html
The Cystic Fibrosis gene (chromosome 7):
1. Cystic fibrosis transmembrane conductance regulator (CFTR)
 maintains proper fluidity of secretions respiratory and pancreatic systems
2. If dysfunctional, secretions are thick and tenacious
 leads to pulmonary disease
leads to exocrine pancreatic failure

7. Cystic
Fibrosis CBAVD / CF
CFTR Dysfunction
Phenotypic Spectrum
CFTR Dysfunction : A spectrum of disease

8. *Most CBAVD is caused by mutations in
the “Cystic Fibrosis” Genes
*Prior to MESA, both partners need to have CF Mutation analysis
This should not be an option, but a necessity
*For further discussion, see the “Genetics” presentation

9. ∆F508 / 5T
CBAVD
∆F508 / ∆F508
Cystic Fibrosis
5T / +
Carrier
∆F508 / +
Carrier
∆F508
+
∆F508 5T allele
Male Genotype
Female Genotype
Transmission of CFTR mutations if partner is a carrier

10. *Treatment of CBAVD
*Epididymal Sperm Aspiration
*The efferent ducts are the tiny
tubes that bring the sperm out from
the testicle into the head of the
epididymis
*It is a great place to get healthy,
new, active sperm
*The sperm are frozen for later use
with ICSI
*We were the first to develop the
frozen-thawed sperm approach
which makes it so much easier for
patients Testis
Epididymal
Remnant
Aspiration of Sperm from the Efferent Ducts

11. *Treatment of CBAVD
After I open up a little tubule,
I aspirate the fluid and will place
it into a special tube to send to
the IVF group for processing and
freezing into multiple vials.
Usually, this is the only procedure
the male partner ever needs

14. *
Fertilization rates equivalent
Embryo quality equivalent
Pregnancy rates equivalent

15. *
*MESA is a procedure to harvest sperm from the epididymis
*If there is a blockage somewhere in this system, sperm
may be able to be surgically retrieved from the
epididymis
*The most common reason in my practice is CBAVD
*Usually get great numbers of active sperm for freezing
*The frozen approach makes it so much simpler for couples
*Not a good idea as a replacement to vasectomy reversal
*See presentation on vasectomy reversal