Sperm aspiration refers to the group of procedures used to obtain viable sperm from the male reproductive tract. The collected sperm are intended specifically for use with intracytoplasmic sperm injection (ICSI). 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 to harvest the sperm. Usually enough sperm are obtained for ICSI and freezing, but at least 1 million mature (passed through the epididymis) motile sperm with normal morphology are required for IUI. Sperm aspiration is reserved for men who have the most severe types of male factor 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 to obtain sperm and each has a different name and acronym. The procedures have clear cut advantages and drawbacks and not all are applicable to every situation. A thorough knowledge and understanding of the cause of the patient's infertility and pathophysiology of the disease process are essential prior to recommending and performing any procedure. Sperm harvesting techniques used to obtain sperm from men with obstructive azoospermia include the following:

MESA stands for microsurgical epididymal sperm aspiration. It is an optimal way of obtaining sperm in those men with a reproductive tract blockage (i.e., after a vasectomy, congenital absence of the vas deferens). The epididymis (organ above the testicle where the sperm are stored) is isolated through 1/2 inch incision made in the scrotal skin . An operating microscope is used to examine the very small tubules of the epididymis that contain the sperm . A dilated tubule is opened and the fluid is collected and examined for the presence and quality of sperm . All of the sperm containing fluid is collected (Fig.3) and taken to the IVF lab for processing, use and freezing. If the fluid is devoid of sperm or only dead sperm are found, then another area of the epididymis is sampled. This is done until enough sperm are obtained to use and to store for future use (picture below).

It is important to save the extra sperm because many patients may not deliver a baby from the first cycle of ICSI. This simple extra step can prevent the patient from having to undergo multiple, future procedures each time sperm are needed. This is also critical for any couple thinking of having more than one child. 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 within 1 day and can return to work and daily activities. MESA is now performed in an office procedure room equipped with an operating microscope and microsurgical instruments. A local anesthetic known as a spermatic cord block is given to numb the area. We routinely administer sedation during the procedure for patient comfort.

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 or percutaneous sperm aspiration is an office procedure and is less expensive than MESA. A needle is placed into the epididymis in the hope that a pocket of 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 can not 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 perform PESA because of poor results and higher rate of complications.

TESE stands for testicular sperm extraction. It is an open procedure performed under direct vision and therefore minimizes potential complications. A small piece of testicular tissue is removed through a 1/2 inch skin incision. The tissue is placed in culture media and morsalized into tiny pieces. Sperm are liberated from within the seminiferous tubules where they are produced and are then extracted from the surrounding testicular tissue. This can be an exhaustive process depending on the degree of sperm production.

TESE is the second best way to collect sperm in men with obstructive azoospermia and the technique of choice for men with non-obstructive azoospermia. It can be performed in an operating room or office procedure room using a local anesthetic. We recommend mild sedation for patient comfort. Sperm harvested using TESE can be frozen and stored for later use. The amount of sperm obtained from the testicular tissue is not nearly as much as obtained with MESA. Testicular sperm do not freeze and thaw as well as epididymal sperm, and are harder to work with in the andrology laboratory.

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 fired 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 difficult to work with and do not get enough sperm to freeze for future use. Several studies have demonstrated that TESE is superior to TESA in all regards. The potential for complications is higher with this technique than with TESE (open biopsy) for two important reasons. TESA is a blind needle stick and bleeding can not be stopped when it is accidentally encountered. 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 because of these reasons that we rarely offer TESA to our patients. Open biopsy (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.

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. TESE or open 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 open biopsy and therefore yields fewer sperm as well. An open biopsy should be performed before canceling an IVF cycle if no sperm are found on a needle biopsy.

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 Rotunda - Hygeia 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.