Hope for Infertile Couples: Microsurgical Testicular Sperm Extraction

National Infertility Awareness Week (NIAW) 2023, which runs from April 23 to 29, aims to enhance understanding and reduce stigma around common barriers to fertility. One such barrier is nonobstructive azoospermia, a condition where sperms are not present in the semen due to an issue with sperm production.

It's a condition urologist Bobby Najari, M.D., the director of male infertility at NYU Langone Health in New York City, sees relatively often. Nonobstructive azoospermia occurs when there's a problem producing sperm as opposed to a blockage in the reproductive tract, known as obstructive azoospermia.

Nonobstructive azoospermia occurs in 10 percent to 15 percent of all infertile men, and 1 percent of all men. It is the most severe form of male fertility problems because roughly half the men with this condition have no sperm anywhere inside the testicle, Najari said.

Fortunately, there is hope for the other half of men thanks to a procedure known as microsurgical testicular sperm extraction (microTESE).

What is microTESE?

A microTESE procedure takes sperm directly from the tissue in the man's testicles. The goal is to get enough sperm to fertilize a woman's egg through assisted reproductive technology (ART).

The patient is under anesthesia while the urologist makes an incision in the testicle to expose the inner tissue. Using an operating microscope to identify healthy-appearing parts of the testicle, the specialist removes small individual pieces known as seminiferous tubules, the structures that produce, maintain and store sperm. An embryologist then processes the sample and provides the urologist with real-time feedback.

"We'll remove the tubules that look more normal and have a fertility lab examine that tissue for the presence of sperm," Najari said. "If they find sperm, great. If they don't, I keep looking."

He said he keeps searching for sperm until either the lab tells him to stop or he has searched through the entirety of one or both testicles. The procedure may take several hours, but the patient typically goes home the same day and resumes daily activities within a few weeks.

Selecting the best tissue to use is a priority for the person performing the procedure, said urologist Martin Kathrins, M.D., an assistant professor of surgery at Harvard Medical School and a urologist at Brigham and Women's Hospital in Boston. He said he's careful to only remove tissue that looks like it may be sperm-bearing. He looks for visual clues, such as opacity and color, in the seminiferous tubules, as well as their diameter.

"The benefit of this surgery is you're removing a small amount of tissue and being very selective about it, so you can limit, hopefully, the risk of damage to the testicle and the risk of low testosterone in the future," Kathrins said.

Ways to perform microTESE

According to Kathrins, a microTESE procedure can be performed in two ways:

1. Frozen, where sperm is cryopreserved and then thawed out later to be used with in vitro fertilization (IVF).
2. Fresh, where the procedure is performed in conjunction with the partner's ovulation induction and egg retrieval.

Many men with azoospermia are not going to have sperm available in the testes, which is why Kathrins doesn't recommend a fresh microTESE. That's mainly because the female partner has to go through the burden of ovulation induction, which involves injectable medication and carries some medical risks.

"It can be expensive and it's time-consuming, only to find out at the last possible second that her partner doesn't have sperm available, so that can be very devastating for a couple," he said.

While Kathrins recommended doing the frozen microTESE ahead of time, one potential downside is that if a small quantity of sperm is frozen, it can be difficult to find sperm again when thawed. However, this is uncommon.

"Like everything in life, there's a risk and benefit to each direction, but in my opinion, there are enough benefits to doing it in a frozen fashion," he said.

What are the chances of pregnancy?

Just because the urologist finds sperm doesn't necessarily mean the procedure will lead to a live pregnancy, as is true of ejaculated sperm during intercourse.

The likelihood of finding sperm in a man with nonobstructive azoospermia is in the mid-40 percent range, and the chance of that sperm resulting in a successful live birth using some means of assisted reproductive technology is 30 percent, according to Kathrins.

"We know that the IVF process doesn't always result in a live birth," Najari said. "Every single egg that undergoes the IVF and ICSI [intracytoplasmic sperm injection] process of injecting a single sperm into it, all those eggs don't fertilize and all of the embryos that have fertilized don't develop in a healthy manner."

Typically, on day five, the embryo is put into the uterus, and unfortunately, a majority of those day-five embryos don't result in full-term pregnancy.

"It definitely is a stressful process throughout because the chances of success are not high," Najari said. "But there is that possibility that we have a great outcome at the end. While it's stressful, it's not the type of situation that someone should be pessimistic about."