This technique is used to help couples where the male partner does not ejaculate sperm. A small number of sperm are obtained directly from the epididymis or testicles in a small surgical procedure sufficient for IVF treatment.
The main methods of surgical sperm retrieval available include:
Which method is used depends on the nature of the problem in the male partner, which needs to be explored carefully first.
A man that produces no sperm in his semen is said to have azoospermia. This may be because of a blockage in one of the tubes that carry sperm from the areas of the testes where they are produced, out to the penis during ejaculation. Obstructive azoospermia can be caused by testicular cancer, as the tumour presses on the vas deferens. This type of cancer is common in young men and can be treated successfully. It can, however, lead to infertility, so surgical sperm retrieval may be performed to store some sperm before treatment begins.
Other conditions cause non-obstructive azoospermia, including having an abnormal cystic fibrosis gene. Men with this condition may not show all the symptoms, but they often have no vas deferens. Surgical sperm retrieval is possible but there is a 50:50 chance that the embryos produced by subsequent ICSI and IVF will have the same genetic abnormality. Options then include using a sperm donor and intrauterine insemination (IUI) or IVF, or having pre-implantation genetic diagnosis (PGD) performed on the embryos to select ones that carry the normal gene.
If the problem that underlies poor sperm production is physical rather than genetic, or if a couple wants to have children after the male partner has had a vasectomy that cannot be reversed, surgical sperm retrieval can go ahead.
When the release of sperm is prevented by a blockage in the vas deferens, or by a vasectomy, several techniques can be used to retrieve the large numbers of sperm that remain inside the testes. The first three involve aspirating sperm using needles or tubes placed through the skin of the testis and are carried out under local anaesthetic. The fourth requires open surgical sperm retrieval and is usually carried out under general anaesthetic.
Testicular sperm aspiration (TESA) is a procedure performed for men who are having sperm retrieved for in-vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI). It is done with local anesthesia and sedation in the operating room or under local anesthesia alone in the office and is coordinated with your female partner’s egg retrieval. We insert a needle in the testicle and aspirate the tissue/ sperm. TESA is performed for men with obstructive azoospermia (s/p vasectomy or congenital bilateral absence of the vas deferens). Sometimes, TESA doesn’t provide enough tissue/sperm and an open testis biopsy is needed.
TESE, testis biopsy and testis mapping are procedures performed for men who have testicular failure. The procedure is performed to see if there are sperm present as well as for pathologic diagnosis to evaluate for causes of abnormal testicular function or malignancy. It is done either as a scheduled procedure or is coordinated with the female partner’s egg retrieval. TESE is usually performed in the operating room with sedation, but can be performed in the office with local anesthesia alone. Patients usually cryopreserve sperm during this procedure for future IVF/ICSI. This diagnostic biopsy is usually used to evaluate for an obstructive etiology. Testicular mapping is when multiple biopsies are taken and “mapped” from the upper, middle and lower portion of the testicle. Microdissection TESE has replaced this as the optimal form of retrieval for testis failure patients with genetic abnormalities, severe failure, or failure from systemic therapies such as chemotherapy or radiation.
Microscopic or Microdissection Testicular Sperm Extraction (TESE) is a surgical procedure performed in the operating room under general anesthesia to retrieve sperm for IVF/ICSI. Microdissection TESE can improve sperm retrieval for men with non-obstructive azoospermia over those achieved previously with standard testis biopsy techniques.
Dr. Boyle uses an operating microscope to visualize blood vessels under the surface of the tunica albuginea, the outside layer of the testis. This allows for placement of the dissection to occur in bloodless regions of the testis.
Instead of planning for multiple biopsies, a large incision is made in the midportion of the tunica albuginea to optimize visualization without affecting blood supply to the testes. Dissections are made and sperm retrieval is completed.
Microdissection is particularly useful to apply in men with smaller testes, as for example in men with Klinefelter’s syndrome. Microdissection is also easier to apply in cases of Sertoli-cell only pattern, as there is a greater difference between tubular diameter size. In cases of maturation arrest, microdissection assists in identifying the limited regions of sperm production.
Microdissection techniques make it feasible to retrieve sperm in men who would otherwise be unable to proceed with IVF/ICSI. Retrieval rates are improved, less testicular tissue is extracted and fertility is optimized for the infertile male. Careful coordination with the female partner’s reproductive endocrinologist is essential.
Microdissection TESE improves sperm retrieval outcomes, and allows retrieval of sperm in men whom sperm retrieval was unsuccessful with standard TESE approaches. Dr. Schlegel, a fertility expert,reports that sperm retrieval success increased from 45% to 63% after introduction of the microdissection technique.
Microdissection TESE is performed “fresh” at the time of egg retrieval, either the day before or day of. Cryopreservation of additional tissue is performed. Donor sperm backup is recommended to be used if no sperm are found on microdissection TESE.
Many azoospermic patients with nonobstructive azoospermia (NOA) might be candidates for sperm aspiration as part of their in vitro fertilization procedure. Because sperm might be present in some but not all parts of the testes of such men, multiple samplings of the testicular tissue are usually performed to increase the probability of finding sperm in NOA patients. These samplings can be done by 2 methods: 1) TESE (testicular sperm extraction), which is actually a surgical biopsy of the testis; or 2) TESA (testicular sperm aspiration), which is performed by sticking a needle in the testis and aspirating fluid and tissue with negative pressure. Sperm extraction is being performed more and more by non-urologists (called andrologists) who are actually either internists or obstetrician-gynecologists. It stands to reason that these non-urologists prefer TESA, given that they are not surgically trained. There has always been debate, however, as to which procedure is “better” at obtaining sperm for successful intracytoplasmic sperm injection.
PESA is a procedure performed for men who are having sperm retrieved for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) who also have obstructive azoospermia from either a prior vasectomy, congenital abnormality such as CBAVD (congenital bilateral absence of the vas deferens, cystic fibrosis) or infection. It is done with local anesthesia in the operating room with sedation or under local anesthesia alone in the office. It can be performed in advance of an IVF cycle and cryopreserved, or coordinated with their female partner’s egg retrieval.
MESA is a procedure performed for men who have vasal or epididymal obstruction (s/p vasectomy, congenital bilateral absence of the vas deferens, cystic fibrosis), obstructive azoospermia. It is either done as a scheduled procedure or is coordinated with their female partner’s egg retrieval. MESA is performed in the operating room with general anesthesia under the operating microscope. Patients usually cryopreserve sperm during this procedure for future IVF/ICSI. With the use of PESA which is minimally invasive, MESA is not performed as frequently, but it does provide the most extensive retrieval for obstructive azoospermia.
Evidence is still accumulating because all of these infertility treatments are relatively new, but one of the most successful combinations appears to be MESA followed by ICSI, which has reported fertilisation and pregnancy rates between 45 % and 52 %.
The ability to freeze and thaw retrieved sperm is a significant advance in the care of men with no sperm in the ejaculate. It has simplified the timing and orchestration of fertility procedures performed on both partners, added convenience to scheduling, and allows couples who need IVF-ICSI to have multiple opportunities to conceive without repeating surgical sperm retrieval. Dr. Turek and others have advanced the idea that motile, frozen-thawed epididymal sperm have IVF-ICSI outcomes equal to fresh epididymal sperm and thus epididymal sperm retrieval procedures are commonly performed before IVF-ICSI cycles and the sperm frozen for later use.
Banking of testicular sperm is a slightly more complicated scenario. In most fertility centers, fresh testis sperm are preferred to frozen-thawed testis sperm. This preference is largely driven by the large decrease in motility observed after testis sperm are thawed (see Table 2), but it is also driven by the generally low or the occasional complete lack of motility observed in fresh testis sperm. Dr. Turek’s experience has been to use motile testis sperm whenever possible, which often requires that it be retrieved fresh. However, given that fresh testis sperm have viability rates that approach 90% (Table 2), Dr. Turek does not require that fresh testis sperm be motile for IVF-ICSI, as viable sperm are all that are necessary for success. As Table 2 suggests, however, if nonmotile, frozen-thawed testis sperm are used for ICSI, a lower fertilization rate should be expected, as only 50% of sperm will be alive. This strategizing forms the basis for the recommendations that Dr. Turek gives to couples who are thinking about banking their retrieved sperm samples.