Last Updated on September 3, 2023 by SCRAdmin
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Microsurgical epididymal sperm aspiration (MESA) is a surgical procedure that is used to retrieve sperm from the epididymis for use in in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) procedures. The epididymis is a small, coiled tube that is located on the back of each testicle, and it is responsible for storing and maturing sperm before they are ejaculated. In some cases, men may have a blockage in the epididymis that prevents sperm from being ejaculated, and MESA can be used to retrieve sperm directly from the epididymis.
During MESA, a small incision is made in the scrotum, and the epididymis is exposed. Using an operating microscope, the surgeon then locates and opens the epididymal tubules, allowing sperm to be extracted. The sperm are then examined under a microscope to ensure that they are healthy and viable before being used in IVF or ICSI procedures. MESA is typically performed on men who have obstructive azoospermia, which is a condition where there is a blockage in the reproductive tract that prevents sperm from being ejaculated.
MESA is a highly specialized surgical procedure that requires significant expertise and training to perform. It is typically performed by a urologist who specializes in male infertility, and it is considered to be a safe and effective method for retrieving sperm for use in IVF and ICSI procedures. While MESA can be an effective treatment option for men with obstructive azoospermia, it is not always successful, and other treatment options may need to be considered depending on the individual case.
What is Microsurgical Epididymal Sperm Aspiration (MESA)?
Microsurgical Epididymal Sperm Aspiration (MESA) is a surgical procedure used to retrieve sperm from the epididymis. It is a type of sperm retrieval procedure used in cases where there is a blockage in the vas deferens, which prevents the sperm from reaching the semen. MESA is performed under general anesthesia and involves making a small incision in the scrotum to access the epididymis.
During the procedure, the surgeon uses a high-powered operating microscope to locate the epididymal tubules, which contain sperm. The surgeon then makes a tiny incision in the tubule and retrieves the sperm using a micropipette. The retrieved sperm can then be used for in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).
MESA is typically used in cases where other sperm retrieval procedures, such as testicular sperm aspiration (TESA) or percutaneous sperm aspiration (PESA), have failed to yield enough sperm. MESA is also useful in cases where a large number of sperm are required, such as for cryopreservation or multiple IVF cycles.
MESA is a safe and effective procedure, with a high success rate. However, as with any surgical procedure, there is a small risk of complications, such as infection, bleeding, or damage to the epididymis. It is important for patients to discuss the risks and benefits of MESA with their doctor before undergoing the procedure.
Who is a Candidate for MESA?
Microsurgical Epididymal Sperm Aspiration (MESA) is a surgical procedure that involves the extraction of sperm from the epididymis, which is a small, coiled tube located on the back of the testicles. This procedure is typically performed on men who have difficulty producing sperm or have obstructive azoospermia, which is the absence of sperm in the ejaculate due to a blockage in the reproductive tract.
Candidates for MESA include men with acquired or congenital reproductive tract obstruction, and men who elect to undergo sperm retrieval as an alternative to surgical reconstruction. Acquired reproductive tract obstruction can occur as a result of infection, trauma, iatrogenic injury, or previous failed vasovasostomy or vasoepididymostomy surgeries. Congenital bilateral absence of the vas deferens (CBAVD) is another common indication for MESA.
Azoospermia, which is the absence of sperm in the ejaculate, can be caused by a variety of factors, including genetic disorders, hormonal imbalances, and reproductive tract obstructions. Men with non-obstructive azoospermia may undergo testicular biopsy to retrieve sperm for use in assisted reproductive technologies such as in vitro fertilization (IVF).
MESA is also a viable option for men who have undergone chemotherapy or radiation therapy, which can damage the testicles and impair male fertility. In some cases, MESA may be recommended as a first-line treatment for male infertility, particularly in cases where other treatments have failed.
Overall, MESA is a safe and effective procedure for men who have difficulty producing sperm due to reproductive tract obstructions or other factors. It is important for men to consult with a qualified reproductive specialist to determine if MESA is the right option for their individual needs and circumstances.
How is MESA Performed?
Preparation
Before the procedure, the patient is given local anesthesia to numb the area. The surgeon then makes a small incision in the scrotal skin to expose the testis and epididymis. The operating microscope is used to provide high-power magnification, which helps the surgeon to identify the optimal areas of the epididymis to retrieve sperm-containing fluid.
Procedure
Microsurgical epididymal sperm aspiration (MESA) involves the retrieval of sperm-containing fluid from the epididymis using high-power optical magnification provided by an operating microscope. Once the optimal areas of the epididymis are identified, the surgeon uses a fine needle to aspirate the fluid. The fluid is then examined under a microscope to identify the presence of sperm.
Recovery
After the procedure, the patient can usually go home the same day. The area may be sore for a few days, and the patient should avoid strenuous activity for a few weeks. Pain medication may be prescribed to manage any discomfort.
MESA is a minimally invasive procedure that is generally safe and effective. The use of an operating microscope helps to increase the chances of finding sperm and minimize the amount of tissue taken out of the testis. However, as with any surgical procedure, there are risks involved, such as bleeding, infection, and damage to surrounding tissue.
Overall, MESA is a valuable technique for retrieving sperm in men with vasal or epididymal obstructions. It is important to discuss the risks and benefits of the procedure with a qualified healthcare provider to determine if it is the right option for a particular patient.
How Does MESA Compare to Other Sperm Retrieval Procedures?
Microsurgical epididymal sperm aspiration (MESA) is one of the several surgical sperm retrieval procedures available to men who have obstructive azoospermia, which is the absence of sperm in the ejaculate due to a blockage in the vas deferens. MESA is a microsurgical technique that involves making a small incision in the epididymis, a tubular structure located on the back of the testis, and aspirating sperm-containing fluid using micropipettes under high magnification provided by an operating microscope.
Compared to other sperm retrieval procedures such as percutaneous epididymal sperm aspiration (PESA), testicular sperm aspiration (TESA), and testicular sperm extraction (TESE), MESA has several advantages. One of the main benefits of MESA is that it yields a higher number of motile spermatozoa, which are sperm cells that are capable of swimming and fertilizing an egg. This is because MESA samples sperm from optimal areas of the epididymal tubules, which have a higher concentration of mature and motile sperm, compared to other areas of the epididymis.
Another advantage of MESA is that it requires only one surgical retrieval procedure to obtain enough sperm for multiple in vitro fertilization (IVF) cycles. This is because MESA can yield thousands and even millions of moving sperm, which can be cryopreserved and used in future IVF cycles. In contrast, other sperm retrieval procedures may require multiple surgeries to obtain enough sperm for one IVF cycle.
MESA also has a higher success rate of sperm retrieval compared to other procedures. According to a study published in the Journal of Urology, MESA has a success rate of 86%, while PESA has a success rate of 64% and TESA/TESE has a success rate of 54%.
However, MESA is a more invasive procedure compared to PESA and TESA/TESE, as it requires an incision in the tunica vaginalis, the protective layer surrounding the testis, and the use of an operating microscope. MESA also requires general anesthesia, which may increase the risk of complications.
Intracytoplasmic sperm injection (ICSI) is a technique used in IVF that involves injecting a single sperm directly into an egg to fertilize it. ICSI is often used in conjunction with MESA to achieve successful fertilization and pregnancy.
Overall, MESA is a highly effective and reliable surgical sperm retrieval procedure that yields a high number of motile spermatozoa for IVF. However, it is important to discuss the risks and benefits of MESA with a healthcare provider to determine if it is the best option for an individual’s specific situation.
What are the Success Rates of MESA?
Microsurgical epididymal sperm aspiration (MESA) is a surgical procedure that involves the retrieval of sperm-containing fluid from the epididymis. MESA is a highly specialized procedure that is typically performed by a urologist or an andrologist. While MESA is a relatively safe and effective procedure, the success rates can vary depending on several factors.
One of the primary factors that can affect the success rate of MESA is the age of the male partner. Studies have shown that the success rate of MESA decreases as the male partner’s age increases. Additionally, the success rate of MESA can also be affected by the cause of the male partner’s infertility. For example, if the male partner has obstructive azoospermia, the success rate of MESA is typically higher than if the male partner has non-obstructive azoospermia.
The success rate of MESA can also be affected by the number of sperm retrieved. In general, the more sperm that are retrieved during the procedure, the higher the success rate of the subsequent fertility treatment. However, it is important to note that not all of the retrieved sperm may be viable or suitable for use in fertility treatment.
The success rate of MESA can also be affected by the type of fertility treatment that is used. For example, the success rate of MESA is typically higher when the retrieved sperm are cryopreserved and used in in vitro fertilization (IVF) compared to intrauterine insemination (IUI). Additionally, the success rate of MESA can be affected by the female partner’s age and fertility status.
Overall, the success rates of MESA are generally high, with pregnancy rates ranging from 30% to 70%. However, it is important to note that the success rates of MESA can vary depending on several factors, and not all couples who undergo MESA will achieve a successful pregnancy.
What are the Risks and Complications of MESA?
As with any surgical procedure, MESA carries some risks and potential complications. These risks can include:
- Bleeding: There may be some bleeding during or after the procedure. In rare cases, this bleeding may require a blood transfusion or additional surgery to stop the bleeding.
- Infection: There is a risk of infection with any surgical procedure. Patients will receive antibiotics before and after the procedure to help prevent infection.
- Pain and discomfort: Patients may experience some pain and discomfort after the procedure. Over-the-counter pain medication can help manage these symptoms.
- Feedback: MESA may cause feedback, a condition where sperm leaks out of the epididymis and into the scrotum. This can lead to swelling and pain in the scrotum. In rare cases, feedback may require additional surgery to correct.
- Cryopreservation: MESA may be done in conjunction with cryopreservation, a process where sperm is frozen and stored for future use. There is a small risk that the sperm may not survive the freezing and thawing process.
- Cost: MESA can be expensive, and some insurance plans may not cover the cost of the procedure. Patients should consult with their insurance provider to determine their coverage.
- Consultation: Patients should have a consultation with a reproductive endocrinologist before undergoing MESA. This consultation can help determine if MESA is the right procedure for the patient and can help manage expectations for the procedure.
Overall, MESA is a safe and effective procedure for men with certain types of infertility. However, patients should be aware of the potential risks and complications associated with the procedure and should discuss these risks with their doctor before undergoing MESA.

Janice Reilly is the Deputy Editor of Content at The Sperm Count Report. She has extensive experience as a writer and editor for medical news blogs, where she covered fitness, reproductive health, nutritional supplementation, and similar subjects.