One of the leading causes of male infertility is an internal plumbing condition called a varicocele. Varicocele refers to an enlarged bundle of veins (the pampiniform venous plexus) leading from the testicles into the abdomen due to reduced blood flow. Believe it or not, a primary function of these veins is to reduce the local scrotum temperature by pumping the blood out of the area. These swollen veins therefore increase the temperature of the testicles (aka cook the balls), and lead to reduced sperm quality. What’s going on, and what can you do about it? Read on…
Varicoceles are the uglier cousins of varicose veins – the enlarged blue veins commonly found in legs in people with poor blood circulation. When the veins do not pump blood as well as they need to, the veins will dilate. Interestingly, while varicoceles can occur to either the left or right side plexus (connected to the left and right testicles), most occur on the left side.
The exact cause of varicoceles remains unknown, although there are 3 leading theories:
Theory 1: Routing of pipes
Your pipes are not symmetric. The left-testicular vein empties into the renal vein at a 90 degree angle, while the right-testicular vein empties into the larger inferior vena cava at a reduced angle. Thus there is a greater likelihood of higher pressure on the left vein, leading to much more common left-side varicoceles.
Theory 2: Poor valving
These veins have one-way valves in them that help prevent back-flow of blood. After all, they’re trying to pump blood against gravity. If the valves do not work properly (or are not present at all), there is a much greater likelihood that the veins will dilate from excess blood.
Theory 3: The “Nutcracker Effect”
This theory proposes that the testicular veins become partially obstructed when the left renal vein gets compressed between the aorta and superior mesenteric artery.
In reality, the root cause is probably a combination of these factors.
Unfortunately, varicocele is a pretty common condition. They are found in 15% of all men, 35% of infertile men who have never fathered a child, and 81% of men who were once fertile but are now infertile (secondary fertility). The condition seems to arise in most men during puberty; varicoceles rarely develop in men over the age of 40.
Varicoceles are progressive legions, meaning that they start small and grow over time. Very small varicoceles usually don’t present symptoms other than occasionally impacting sperm quality. In the case that you have an abnormal semen analysis, the doctor may perform an ultrasound of the scrotum to look for small varicoceles or inflammation of the epididymus. While performing the ultrasound, they will measure the diameter of the plexus of veins. Technically, a varicocele refers to a plexus that is greater than 2mm in diameter (normal diameter is 0.5mm – 1.5mm).
As the varicocele grows over time it can be identified by examining the testicle. Doctors will feel for an enlarged bundle of veins along the spermatic cord. If the varicocele is large enough, you may be able to feel it yourself as they can make the scrotum feel like a “sack of worms.” Even larger varicoceles are visible and you can see the bluish color of the vein through the thin skin of the scrotum.
Some men experience other symptoms associated with the varicocele. It can cause the testicles to hang lower than usual, feel heavy (particularly after long periods of standing) or even cause a dull pain. If you are experiencing any of these symptoms and are thinking about having children, it is a good idea to go in and get checked out.
Many studies have linked poor sperm quality to varicoceles in subfertile men. The effects include diminished sperm count, motility, and morphology. Some researchers have also linked varicoceles to reduced sperm function, meaning that despite normal count, motility, and morphology, the sperm is still unable to fertilize an egg. However, the exact physiological explanation of why varicoceles inhibit male fertility remains partly controversial. There are several leading theories:
The veins help keep the scrotum a few degrees below normal body temperature, which is essential for proper sperm production. If the vein function is impaired, the heat exchanger loses its efficiency and scrotal temperature can increase. (This is why we call varicoceles the internal ball cooker).
2. Venous pressure
Varicoceles may cause the blood pressure in the veins to increase. The increased pressure may inhibit metabolic processes within the testicles, and also reduce vascular drainage from the area which can lead to an accumulation of toxins in the area.
3. Hormone imbalance
Many studies have linked varicoceles to lower levels of testosterone. This finding suggests that the condition may affect of the Leydig cells in the testicles, which are responsible for testosterone production.
4. Reactive oxygen species
The production of reactive oxygen species (ROS) is critical to proper sperm function. However, an abundance of ROS can impair sperm motility and morphology. High ROS levels in semen have been found in men with varicoceles.
Not all varicocele need treatment. If you have no plans to have kids (or more kids), if you’re not experiencing pain, if you have no trouble conceiving, or even if you do, if your semen parameters (count, motility, etc.) are normal, you and your doctor may decide to put off or even skip treatment. However, for guys still planning to start or grow a family, whether through intercourse, artificial insemination, or IVF, it’s a good idea to examine treatment options if your semen parameters are abnormal and you’re having difficulty conceiving.
This is performed by a urologist to repair (by obstructing) the variocele, and it’s the most common treatment. With a successful repair, most men will see an improvement (after 4-6 months) in count, motility, and morphology, and a decrease in sperm DNA fragmentation.
The procedure itself is usually a minimally invasive, microscopic surgery to cut and remove the portions of veins causing the problem. In most cases, this is an outpatient procedure with a few days off of work. Sometimes, depending on the size, number, and position of variocele, this procedure is performed more invasively, either through laparoscopy (laser microscope) or open surgery (larger incision). Laparoscopy, and to a larger extent open surgery, will involve cutting through abdominal muscle, increasing recovery time. Although all variocelectomies tend to improve sperm health, the best outcomes, shortest recovery times, and the fewest complications and recurrences are associated with the microsurgical approach.
The larger the variocele, the more improvement is likely to be shown with surgery. An advantage of variocelectomy is that the surgeon has the vantage point to not only cut the vein currently causing the problem, but also to take care of veins that may cause future problems–without cutting so many veins as to create a new current problem. The most common complication of variocelectomy (all types) is hydrocele (fluid-filled sac around testicle, makes your scrotum swell). Others include injury to the testicular artery and recurrence of varicocele.
Microsurgery can be done with local anesthesia, which reduces general surgical complications; the other methods require general anesthesia (in other words, you’re knocked out) with intubation (a tube down your windpipe to help you breathe, since some of the drugs used in effective anesthesia make it harder to breathe). In some studies, microsurgery was shown to be have fewer complications (hydrocele) and fewer recurrences than the other two methods. Talk with your urologist to understand what options are available to you.
A possible alternative treatment to surgery is to puncture the dilated vein through the skin to embolize (deliberately block) the varicocele with a chemical that acts a bit like an epoxy for the blood vessels. Coils and balloons can also be used for embolization, which is less invasive than microsurgical ligation (variocelectomy), and can be performed with local anesthesia.
Embolization, often performed by an interventional radiologist, is well-tested in other conditions (such as clots and aneurysms) in other parts of the body. It’s the sort of procedure you’ve may have seen the fictional cardio-thoracic surgeon Dr. Christina Yang perform without need for suction or gauze, but confidently guiding the tiny, flexible needle-and-thread-looking stuff on the ghostly screen.
This method is promising but not well-studied treatment for varicocele repair, though it was first used in this application in 1977. Some types and locations of varicocele may not be suitable for this approach. Also, for embolization in general, recurrence may be an issue.Talk with your doctor to see if this option makes sense for you.
From a distance, this technique looks a lot like embolization. In both, ultrasonic imaging is used to guide a flexible needle into the heart of the variocele (local anesthesia). Except the goal is to dissolve or shrink rather than block (similar results).
This approach is well-tested in varicose veins, the usually leg-located cousin of the testicular varicocele. It has also been in use for varicocele treatment as early as the late 1970s, and is shown to yield improvements in sperm quality. However, if the results for testicular varicocele are similar to the non-reproductive applications of sclerotherapy, it may perform better in the short term than a surgical approach (say, 1 year), but worse in the longer term (more like 5 years).
A main complication of any sclerotherapy is adverse reaction or surrounding tissue damage due to the sclerosing agent used. For this reason, foam preparation of the sclerosing drug is usually chosen for its demonstrated safety (more contained) and efficacy (maximizes surface area and potency in target treatment area). Another potential complication of this procedure is blood clots and swelling of veins due to blood clots. Like embolization, not all varicocele will be accessible by or appropriate for this approach.
If you put a couple handfuls of fertility experts in a room and asked them to determine, by consensus, the most effective method of varicocele treatment for all individuals, you might want to hide a camera in the room and pop some popcorn. Part of the reason it’s difficult to agree on the best treatment is that the underlying links between varicocele, facets of sperm quality, and ultimately impaired male fertility are not clear. We know varicocele adversely affect male fertility, but studies produce conflicting data when researchers try to correlate successful (by sperm quality and by lack of complications or recurrence) repairs with increased pregnancy outcomes. We know that varicocele treatment improves sperm count and quality outcomes, but is that the whole picture?
Individual differences in size, shape, number, and location of varicocele, as well as differences in the effect the varicocele is having on sperm quality aspects, may impact treatment decisions and outcomes. In addition, some surgeons are more practiced and skilled in particular techniques than others, so be sure to address this with your doctor. As an adult man, when considering any varicocele treatment for the goal of improved fertility, it’s a good idea to sit down with your doctor, your baseline sperm quality results, and any other tests your doctor may have performed in diagnosis and evaluation, and decide which option will be right for the two of you.
- “Varicocele-induced infertility: Newer insights into its pathophysiology.” M.L. Eisenberg and L.I. Lipshultz, Indian J. Urol., 27(1): 58-64, 2011.
- “Varicocele and male infertility: Part II. Pathophysiology of varicoceles in male infertility” C.K. Naughton et al., Human Reproduction Update, 7(5): 473-481, 2001.
- “Varicocelectomy: microsurgical inguinal varicocelectomy is the treatment of choice.” S. Binsaleh and K.C. Lo, Can Urol Assoc J., 1(3): 277-278, 2007.
- “Male infertility and varicocele: myths and reality” PD Kantartzi et al., Hippokratia, 11(3): 99-104, 2007.