Sperm Harvesting for In Vitro Fertilization
Sperm aspiration refers to the group of surgical procedures that are used to obtain viable sperm from the male reproductive tract. The collected sperm are intended specifically for use with intracytoplasmic sperm injection (ICSI). This is a process which injects a single sperm directly into an egg.
A frequently asked question is can the sperm harvested by these techniques be used for insemination? There are not enough sperm retrieved to perform intrauterine insemination (IUI) regardless of the technique used in sperm havesting. Usually enough sperm are obtained for ICSI and freezing, but at least 5-8 million mature (passed through the epididymis) motile sperm with normal morphology are required for IUI.
Treating Azoospermia with Sperm Aspiration Procedures
Sperm aspiration is reserved for men who have the most severe types of male infertility including no sperm in their ejaculate (azoospermia) or sperm that are not motile or are dead (necrospermia).
There are two main reasons why sperm may be absent from the semen (necessitating sperm aspiration). Obstructive azoospermia is the result of a blockage in the male reproductive tract. Sperm production in the testicle is normal but the sperm are trapped inside the epididymis. Non-obstructive azoospermia is the result of severely impaired or non-existent sperm production. It is precisely these situations that require advanced reproduction technologies such as ICSI to establish a pregnancy.
Four different techniques can be used in sperm harvesting and each has a different name and acronym. The procedures have clear-cut advantages and drawbacks, and not all are applicable to every situation. Dr. Werthman will need to have a thorough knowledge and understanding of the cause of your infertility prior to recommending and performing any particular procedure.
Surgical Techniques for Obstructive Azoospermia
MESA: Micro-surgical Epididymal Sperm Aspiration
MESA, or Microsurgical Epididymal Sperm Aspiration, is an optimal way of obtaining sperm in men with a reproductive tract blockage (i.e., after a vasectomy, or in the congenital absence of the vas deferens). In this procedure, Dr. Werthman will extract sperm from their storage site in the epididymis with the aid of a surgical microscope.
This is a relatively painless and minimally invasive procedure performed in our office under local anesthesia.
MESA allows for the recovery of the best quality and highest quantity of sperm compared with the other techniques. It is also the safest procedure, and in our experience produces the least amount of complications, discomfort and swelling.
Each step of the procedure is clearly visualized under the microscope and the testicle itself is not entered. Any bleeding can be quickly halted. Most patients recover from MESA withinone1 day and can return to work and daily activities.
The disadvantage of MESA is mainly the relative unavailability. MESA is usually offered only at centers specializing in the treatment of male infertility because of the need for specialized equipment, an operating suite and a trained infertility microsurgeon. MESA is more cost effective than other techniques because it is usually a one-time expense whereas the other sperm retrieval techniques may need to be repeated multiple times.
PESA: Percutaneous Epididymal Sperm Aspiration
PESA, or Percutaneous Epididymal Sperm Aspiration is less expensive than MESA, but it is also less effective. During this procedure, a needle is placed into the epididymis with the hope that a pocket o sperm will be found and aspirated.
While PESA is conceptually appealing, very few sperm are actually collected for use and rarely are enough sperm obtained for freezing. In our experience, frequently a second type of procedure had to be performed to save the IVF cycle because PESA failed to yield usable sperm.
PESA is a blind procedure in that the surgeon cannot see where he is placing the needle. When a blood vessel is accidentally hit, it will continue to bleed and result in a collection called a hematoma.
Male infertility experts rarely recommend PESA because of poorer results and a higher rate of complications.
Surgical Techniques for Non-Obstructive Azoospermia
Sperm are rarely present in the epididymal tissue of patients who have non-obstructive azoospermia. Therefore epididymal procedures such as MESA or PESA are inappropriate for retrieving sperm from these men. Micro-TESE or micro-surgical testicular sperm extraction is the optimal technique for obtaining sperm in this situation.
Men who produce very few sperm may need to have multiple areas of the testicle sampled before enough usable sperm are found. Needle biopsy does not yield as much tissue as Micro-TESE and therefore yields fewer sperm as well. Micro-TESE should be performed before canceling an IVF cycle if no sperm are found on a needle biopsy.
Micro-TESE: Microsurgical Testicular Sperm Extraction
If viable sperm cannot be found in the epididymis, Dr. Werthman may recommend harvesting sperm directly from the testicles in an effort to find viable sperm. Even men with very poor sperm production generally have areas in the testicles in which viable sperm are being produced; the challenge is in finding those pockets. With this micro-surgical procedure, Dr. Werthman can observe the interior of the testicle and select the best candidate areas to examine for sperm production.
Once a section is identified, Dr. Werthman will remove a small piece of testicular tissue. The tissue is placed in culture media, and exhaustively examined to find sperm that can be used for ICSI.
TESA: Testicular Sperm Aspiration (Needle Biopsy)
TESA, or testicular sperm aspiration, is a needle biopsy of the testicle. It is an office procedure performed under local anesthesia. A small incision is made in the scrotal skin and a spring-loaded needle is placed through the testicle.
While it is possible to retrieve sperm using this technique, the amount is often low because the needle cuts a thin sliver of tissue. Many embryologists find this small amount of tissue difficult to work with and do not get enough sperm to freeze for future use.
Several studies have demonstrated that the Micro-TESE is superior to TESA in all regards. The potential for complications is higher with a TESA for two important reasons. 1) TESA is a blind needle stick, and bleeding cannot be stopped when it is accidentally encountered. 2) The needle is larger in diameter than the intratesticular artery and can sever the artery, potentially cutting off testicular blood supply. The testicle may shrink and die.
It is for these reasons that we rarely offer TESA to our patients. Micro-TESE is more effective and potentially safer than needle biopsy (TESA) and is our technique of choice for obtaining testicular sperm for men with non-obstructive azoospermia.
Testicular Mapping: A technique to be avoided
A treatment approach called testicular mapping, was developed to allow the surgeon to blindly test multiple areas of the testicle for sperm. In this procedure, the doctor uses a fine needle to aspirate and sample multiple areas of the testicle.
A grid with 9-12 sections is drawn over the testicle and a needle is blindly inserted into each area to remove (aspirate) a small section of the tubules and sample them for sperm.
Too few sperm are found with this technique to use with IVF or freeze for the future because the fine needle can only remove a miniscule amount of tissue in the aspirate. This means that once sperm are located and the map is created, another microsurgical procedure (microTESE) needs to be performed to find those tubules that have sperm and remove them to have enough sperm to use for IVF or to freeze.
In short, men who submit to testicular mapping will (at best) find an area or areas of their testicles that are actually producing sperm. They will need to undergo a second surgical procedure on their testicles in order to actually put any of that sperm to use in an IVF cycle.
Dr. Werthman strongly recommends against using testicular mapping as an unnecessary, painful and potentially dangerous procedure.
Sperm Aspiration is very successful when the proper technique is used
Sperm aspiration (when performed using the appropriate technique) is usually a very successful, minimally invasive procedure that allows even men who make very few sperm to conceive a child of their own. Our goal at the Center for Male Reproductive Medicine in Los Angeles is to provide the safest, most effective patient care and to collect as much good quality sperm as possible to minimize the need for future multiple surgeries.