Advances in reproductive medicine over the last generation have allowed most men who were formerly considered absolutely sterile to father biological children.
Along with the development of new and viable procedures, however, we have also seen the occasional advocacy of a procedure that is at best a waste of time and at its worst destructive to men hoping to father biological children: testicular mapping. This procedure has been repudiated by the vast majority of male reproductive experts in favor of another innovative and effective procedure, microsurgical testicular sperm extraction (micro-TESE). For the vast majority of men, testicular mapping is unnecessary.
What is it about testicular mapping that makes it so undesirable? And why is micro-TESE the treatment that male reproductive experts recommend?
Advances in Reproductive Medicine
Advances in reproductive medicine over the last generation have come on two fronts. The first was the advent of In-Vitro Fertilization (IVF) with Intra-Cytoplasmic Sperm Injection (ICSI). This technological breakthrough reduced the required number of sperm needed to fertilize an egg from millions to just one sperm per egg and allowed for the use of (less mature) sperm harvested directly from the testicle. This meant that men with very low sperm counts or no sperm in the ejaculate that could not be improved with other means had a new way of effectively conceiving. What it also led to was a re-examination of our understanding of how to the testicles function.
It turns out that men who have no sperm in the ejaculate because of problems with sperm production, a condition called Non-Obstructive Azoospermia (NOA), actually may have small pockets of sperm production within the testicle. In fact, most men with NOA (50-70% in fact) produce small amounts of sperm inside the testicle that can be used with IVF/ICSI to create a baby. The challenges have been to develop techniques and procedures to improve the chances of finding testicular sperm and to create effective strategies to best use that sperm with IVF.
Take Home Point:
Most men with NOA have small amounts of sperm production within the testicle and can become biological fathers.
Testicular Physiology and Anatomy
It is important to have a basic familiarity of how sperm production occurs in both the normal and abnormal testicle in order to understand how to best find sperm in men with NOA.
The testicle is comprised of hollow microscopic tubes called seminiferous tubules and it is inside the walls of these tubules that sperm production, development, and early maturation takes place.
Sperm production is a multi-step process that occurs in 70-90 day cycles. In the normal testicle, sperm are produced in most, if not all of the seminiferous tubules although at varying rates. In the abnormal testicle, few, and in some cases none of the seminiferous tubules produce sperm. When sperm production does occur, it is usually focal meaning in just a few small areas within the seminiferous tubules/testicle and in a very uneven and unpredictable way.
Interestingly, the seminiferous tubules that do produce some sperm look more normal, larger, and fuller than tubules that typically don’t make sperm, which appear collapsed, whitish in color, and scarred. Because the normal and abnormal tubules have such a distinct appearance, we can use this difference to increase the chances of finding sperm.
The seminiferous tubules are microscopic and not visible to the naked eye. A powerful operating microscope is needed to actually see them and is employed to examine the inside of the testicle in search of normal appearing tubules and sperm. This procedure is called testicular microdisection or Micro-TESE for short and is the best procedure to find sperm in NOA. This procedure increases the chances of finding sperm significantly over other types of testicular biopsy that actually hurt the chances of using the sperm to make a baby.
Take Home Point:
The ability to magnify and see the seminiferous tubules doubles the chances of finding sperm over routine testicular or needle biopsy, from 30 to 50-70 percent.
Random Testicular Biopsy, A Thing of the Past
Historically, the way most urologists performed testicular biopsies to remove tissue and try to get sperm was in a random and limited way. They would remove one or two small pieces of testicular tissue containing seminiferous tubules, without being able to see them using the microscope, and then send them to a pathologist to mount on slides and examine cross sections of the seminiferous tubules to see if there were sperm inside.
Sometimes the urologist will use a spring-loaded needle biopsy gun that can remove only a sliver of testicular tissue without making an incision and submit the tissue to the pathologist. Unfortunately, the process that the pathologists use to fix the slides kills the sperm, so we never get an assessment of whether the sperm are motile or alive or how mature the sperm are, and most importantly, it doesn’t allow us to use the sperm or freeze it for later use.
This means that a man who has sperm found on a biopsy will have to have another surgery to get more sperm to use. Not only that, but half the men who actually are making some sperm will have none found by these random or needle biopsies and will lose the chance to become a biological parent.
Clearly, random and needle biopsies performed by general urologists are not the most effective way to approach NOA and can actually cause more harm than good, because half the men that have small amounts of sperm production will be misdiagnosed and the other half will have to have a second surgery to get sperm to actually use.
These procedures are called blind or random biopsies because the surgeon can’t view the seminiferous tubules they are removing. The blindness of the procedure also increases the danger that the surgeon may puncture a blood vessel that they can’t see, causing internal bleeding and complications.
Take Home Point:
In 2013, no patient should have a random testicular biopsy without being offered the option to freeze any sperm that are found or to use the sperm timed with an IVF procedure.
What is Testicular Mapping?
The treatment approach called “testicular mapping” was developed using a fine needle to aspirate and sample multiple areas of the testicle and try to improve the chances of finding sperm. It is an expanded version of the random testicular biopsy.
In this technique, 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. The aspirate is placed on a glass microscope slide and analyzed by a cytologist (specialized pathologist). A map is then made of each testicle, showing which areas had sperm found.
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. 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.
Testicular mapping is also a blind procedure. As with the random biopsy, there is danger that the urologist will puncture a blood vessel and cause internal bleeding and complications. That risk is magnified by the number of times that the needles are blindly inserted to extract tissue.
In short, men who undergo successful mapping will need to have a second surgery on their testicles in order to have a child. Furthermore, blindly placing a needle in the testicle does not allow as thorough a search as testicular micro dissection. A dilemma arises because statistically, most men have some degree of sperm production so that means that most men will have this unnecessary procedure performed to find out if they have sperm before going through the process of using the sperm or freezing them.
Take Home Point:
Testicular Mapping with a fine needle can detect sperm production and its location, but if sperm are found, a second microsurgical procedure will be required to use the sperm. If no sperm are found with the mapping procedure, then they still might be found with microTESE. We have to ask the question: Does the testicular mapping approach make sense? Common sense, statistics, and the vast majority of male reproductive experts would say NO and have stopped doing this procedure in favor of microTESE.
Microsurgical Testicular Sperm Extraction (micro TESE, Testicular Microdissection)
The best way of finding sperm that can be used for IVF is with a surgical procedure called microsurgical testicular sperm extraction or micro-TESE. As previously mentioned this approach uses an operating microscope to examine the seminiferous tubules within different areas of the testicle. Watch our animated video describing the micro-TESE procedure.
Because we can oftentimes select the best and most normal appearing tubules when we magnify and visualize them, we can significantly improve the chances of finding sperm over the random biopsy or blind needle biopsy approach. We can also remove more tubules and examine all areas of the testicle under the microscope and therefore get the maximum amount of sperm possible from the patient. We can also get sperm prior to the start of an IVF cycle and effectively freeze them.
Couples can choose to time the micro-TESE in conjunction with the egg retrieval portion of an IVF cycle so that the sperm can be incubated for a day or two and can be injected into the eggs. This offers the statistically best chances of men with NOA to father a child. Unfortunately 30-40% of men with NOA will not have sperm found so patients need to consider a back-up plan if combining the micro-TESE with the IVF cycle.
For many couples, having donor sperm available should the micro-TESE not yield usable sperm is an excellent option that allows them to build a family. The donor sperm is obtained from a sperm bank in advance and is thawed and injected into the eggs during the IVF cycle.
For some couples, donor sperm is not a viable option. For these couples, performing a micro-TESE and freezing sperm before preparing the female partner for IVF makes sense. It avoids an unnecessary IVF cycle if no sperm are found, and the pregnancy rates with fresh or frozen sperm are very similar.
Micro-TESE with freezing certainly makes the most sense for couples that are not interested in using donor sperm as a back-up plan with IVF, and are not willing to risk an IVF cycle with a 50-70% chance of finding sperm. For them, knowing there is sperm production within the testicle allows them to proceed with IVF comfortably. Therefore, the testicular mapping procedure is unnecessary because it does not allow for sperm freezing. This is exactly why we stopped offering testicular mapping to patients. It makes more sense on a number of levels to just perform the micro-TESE with the IVF cycle or as a stand-alone procedure that will allow us to freeze any sperm that are found for use with a future IVF cycle.
Take Home Point:
Micro-TESE either combined with a fresh IVF cycle or with sperm freezing gives a couple with NOA excellent chances of conceiving. Testicular mapping is an unnecessary diagnostic procedure that only checks if sperm are present but does not allow sperm harvesting and freezing. Most men who undergo mapping will have to have a micro-TESE to get sperm to use anyway and will have undergone the mapping procedure but not gotten any useable benefit from it. It is important that couples understand this before making a decision on how best to proceed.