By Michael Feinman, MD, FACOG Board Certified, Reproductive Endocrinology and Infertility
In the late 1980’s, Dr. Sherman Silber in St. Louis, proved that sperm obtained directly from the scrotum could be used to successfully fertilize eggs and achieve viable pregnancies. While this procedure was originally intended for men who are born with an obstruction in the genital tract (congenital absence of the vas deferens), it has become clear over the past decade that men with previous vasectomies can benefit from similar procedures as well.
The development and maturation of sperm occurs in the testes. The testes also produce most of the testosterone in men. The sperm begins its trip in the male through an enlarged portion of the ducts called the epididymis. This duct eventually becomes the vas deferens (vas). Along the route of the vas, the prostate and seminal vesicles add the fluid portion
of the ejaculated semen. When a vasectomy has been performed, the vas deferens is blocked before the area where the seminal vesicles add the fluid. That is why these men still produce semen, but no sperm. Dr. Silber microsurgically removed sperm from the epididymis and achieved viable pregnancies through assisted reproductive procedures, thus proving that sperm do not have to make the trip through the ducts to achieve fertilizing potential.
Vasectomies represent an important and effective method of “permanent” birth control. For a variety of reasons, a small percentage of men who have a vasectomy later desire more children. Until recently, if semen was not frozen at the time of the surgery, microsurgical reversal of the vasectomy has been the only option for these men. Vasectomy reversal has several disadvantages, however. Vasectomy reversal represents major surgery of the scrotum. Most men with longstanding vasectomies develop sperm
antibodies that may inhibit fertilization, even if the reversal procedure is surgically successful. Finally, reversals done more than seven years from the original procedure are associated with very poor pregnancy rates. Unfortunately, many men seeking fertility after a vasectomy fall into this last category.
Removing sperm directly from the scrotum, combined with In-vitro fertilization (IVF), represents an excellent alternative to vasectomy reversal. The original microsurgical approach is known as Microsurgical epididymal sperm aspiration, or MESA. This procedure produces enough sperm to freeze for future use. However, like vasectomy reversal itself, the procedure involves major surgery of the scrotum, is relatively expensive, and often can be performed only once on each side because scar tissue hinders the ability to find the duct on subsequent attempts.
An alternative to MESA is open testicular biopsy. In this procedure, a very small incision is made in the scrotum and a small piece of testicular tissue is removed. The procedure can be repeated easily, if necessary, although it often produces enough sperm to freeze for future attempts. Both the biopsy and MESA can be done with either light anesthesia or local anesthesia, depending on the preferences of both the surgeon and the patient. The recovery time is less than for MESA, and more similar to the non-surgical procedures discussed below. This procedure can also help men who have no sperm in their semen, but may have sperm in the testis.
Over the past few years, HRC doctors have developed two non-surgical alternatives to MESA. The first approach is Percutaneous epididymal sperm aspiration, or PESA. The second alternative is Testicular sperm extraction, or TESE. Both procedures can be done using local anesthesia. With PESA, a small needle is guided through the skin into the epididymis, and a small amount of fluid containing sperm is aspirated. In contrast, with TESE, a small amount of tissue is removed directly from the testis using a small biopsy needle. TESE generally does not produce enough sperm for freezing; PESA might. The sperm obtained from these methods can fertilize eggs using intracytoplasmic sperm injection (ICSI), as part of an IVF cycle. None of these procedures produce enough mobile sperm for simple artificial inseminations.
Potential complications of the non-surgical procedures include infection and bleeding.
Bleeding under the scrotal skin can theoretically cause the formation of a painful blood clot known as a hematoma. These potential problems are similar with the more invasive alternatives. In more than 10 years of performing these procedures, we have not seen either of these complications.
Before proceeding with any of these treatments, the male partner should be evaluated by the person who will perform his procedure. An appropriate history and physical examination should be performed, focusing on potential factors that could impact on likely successful aspiration of sperm. The physical exam can identify potential problems that might be encountered and can help the physician estimate the likelihood of finding adequate amounts of viable sperm. We measure serum levels of testosterone and FSH in the men to make sure they are producing enough hormones to sustain normal sperm development.
As with routine IVF cycles, the female partner uses injectable hormones to stimulate multiple egg production and control the timing of ovulation. The egg retrieval is done vaginally, using an ultrasound probe to guide a needle into the ovaries. This procedure can be done with local anesthesia or with conscious sedation. MESA and open biopsies can be performed on the day of or the day before the egg retrieval. The PESA or TESE is done on the same day, and the eggs are fertilized through ICSI a few hours after the egg retrieval. Three or five days later, a small number of embryos are inserted through the cervix into the uterus. The number of embryos transferred depends on the age of the woman and the quality of the embryos. Extra embryos can be frozen for future use. The doctors at HRC address the issue of multiple births by transferring lower numbers of embryos in younger patients. We can do this, in part, because of the quality of our freezing program, giving couples a realistic second chance.
The choice of procedure is largely dependent on physician preference and laboratory experience. Both the urologist and the reproductive endocrin-ologist can help patients decide which alternative is best for them. All the variations of the male procedure are available at HRC. We believe there is no significant difference in the success rates between the different procedures. The success rates vary, based on various factors, maternal age being one of the most important. For couples in whom the male partner has a vasectomy that is more than seven years old, these success rates following single procedures are greater than the overall success rates with vasectomy reversal. For younger women, the overall success rate following the initial combination of PESA/TESE and IVF, is enhanced if there are frozen embryos available for another embryo transfer.