Sperm transport obstructions are a common cause of male infertility. Learn about blockage development and treatment options

The second most common cause of male infertility is sperm transport obstructions. These blockages of the tubes (the epididymis and vas deferens) carrying sperm away from the testes can prevent semen ejaculation. This obstruction may occur at any location from the epididymus through to the ejaculatory ducts located in the prostatic urethra. Approximately 30% of infertile men suffer from sperm transport obstructions.

Causes of sperm transport obstructions

The causes of sperm transport obstructions may be congenital or develop over time. In the case of vasectomies, the obstruction is a deliberate form of contraception. The four main causes of sperm transport obstructions are:

Infections

Infections within the reproductive tract may cause blockages that prevent sperm transport. Sexually transmitted diseases are the most common source of infection, especially Chlamydia, mycoplasma, and gonorrhoea1. These infections can damage the epididymis, causing scaring and blockage. The epididymis is located adjacent to the testicle and obstructions can prevent sperm from leaving the duct. This may not change ejaculate volume. However, these obstructions will significantly reduce sperm count and lead to infertility.

There are a range of treatment options for men whose fertility has been compromised due to infections. Often once an ongoing infection has been diagnosed it can be treated and fertility will be restored. However if damage has been sustained to the sperm transport tract, surgery may be required to remove obstructions. The success rate of these procedures is high and usually men regain fertility. In severe cases, removal of sperm for ARTs may be the only option.

Prostate related causes

The ejaculatory duct passes through the prostate gland. Any infections of the prostate can lead to swelling and obstructions that stop sperm from being ejaculated. A blockage in this location will also reduce ejaculate volume as the fluid is produced by both the prostate and seminal vesicles.

In some cases, infections of the prostate can also directly damage sperm cells. Congenital abnormalities may cause cysts to form on the prostate gland. These cysts can compress the ejaculatory ducts and block sperm transport. Surgery to remove cysts or other blockages can help to restore fertility.

Vas deferens absence

The vas deferens is responsible for transporting sperm to the ejaculatory ducts from the epididymis. In approximately 1% of men the vas deferens is absent. This congenital condition is often accompanied by a shortened epididymis. It is caused by a genetic mutation to the cystic fibrosis transmembrane regulator (CFTR) gene2 and is usually accompanied by absence of seminal vesicles. This causes reduced ejaculate volume from approximately 2 ml to around 0.5 ml. Ejaculate is also more acidic in the absence of seminal vesicles.

Unfortunately, there is no surgical way to replicate the vas deferens. Nevertheless, it is possible to retrieve sperm from the ducts within the existing epididymis or testicle. This sperm can be frozen and used in IVF or other assisted reproductive technologies (ARTS). However, as this condition arises from a genetic mutation, it is important to undertake genetic screening of both partners. If CFTR mutations are identified in both partners, the risk of cystic fibrosis is high in their children born from ARTs.

Vasectomy

The most common cause of sperm transport obstruction is a vasectomy. This surgical procedure involves removing a section of the vas deferens. This is the tube responsible for carrying sperm to the urethra at the bottom of the bladder. This is a long-term, safe contraceptive option. However, many men later choose to have the procedure reversed so that they can father more children.

Although there are no long-term changes to testosterone levels following a vasectomy, the sperm producing tubes can get damaged over time. Also, blockages and scaring of the epididymal tubes is common. In 80% of men that have had a vasectomy, sperm antibodies form3. Therefore, a vasectomy reversal is less successful as more time elapses.

Symptoms of sperm transport obstructions

In many cases, there may be no obvious symptoms associated with sperm transport obstructions. If the blockage is caused by infections, there may be some unusual discharge from the penis, inflammation, and discomfort while urinating or ejaculating. Less than normal ejaculate volume can also be a sign of a blockage.

Diagnostics

A semen analysis is often the first diagnostic test to determine if a sperm transport obstruction is present. If sperm are absent from the sample or in very low numbers, it’s a good indication that a blockage may be present. A transrectal ultrasound may be necessary to confirm an obstruction. This imaging procedure checks prostate health and can help to identify any blockages within the seminal vesicles and ejaculatory ducts.

Treatment options

Surgery

With the exception of a vas deferens absence, most sperm transport obstructions can be reversed with surgery.

In the case of vasectomy reversals, a microsurgical vasovasostomy may be preformed. This procedure aims to restore fertility by reconnecting severed vas deferens.

Other obstructions within the sperm transport ducts may be treated using a transurethral resection of the ejaculatory duct (TURED), or a vasoepididymostomy. A TURED procedure involves opening blockages with a cystoscope passed through the urethra and into the ducts. A vasoepididymostomy is the most common microsurgical method performed for fixing epididymal obstructions. However, it is also the most difficult and requires a highly practiced and skilled surgeon. The procedure involves the surgical joining of the epididymis and the vas deferens to allow fluid transport.

Sperm removal

Instead of undergoing reconstructive surgery, some men choose to undertake a procedure to remove viable sperm for ARTs. This is also an option for men ineligible for a microsurgical vasovasostomy, vasoepididymostomy, or TURED surgery. There are several different procedures available for removing sperm.

Percutaneous epididymal sperm aspiration (PESA): While under local anaesthetic, sperm is removed from the epididymis using a fine butterfly needle.

Microsurgical epididymal sperm aspiration (MESA): This allows sperm to be retrieved in greater numbers compared with PESA. However, it is a more invasive procedure. It involves retrieving sperm directly from individual epididymal tubes with a microscope.

Testicular sperm aspiration (TESA): Sperm is recovered from the testicles using a needle and syringe to puncture the testis and aspirate sperm without the need for a scrotal incision.

Treatment duration and recovery

TURED surgery, vasoepididymostomy, and microsurgical vasovasostomies are performed under general anaesthetic and take approximately one to two hours. The duration of epididymal or testicular sperm retrieval processes can take a few minutes up to an hour depending on the treatment and how quickly sperm can be located. Depending on the procedure, it may be performed under general or local anaesthetic.

Recovery times will vary depending on the treatment. It can take anywhere from a few days up to a couple of weeks. Strenuous activity should be avoided and scrotal supporters may need to be worn until fully recovered. In some cases antibiotics may be prescribed to reduce the risk of infection. Most men are able to return to work within a few days and resume normal activities within a couple of weeks.

Possible complications include infection, pain, and bleeding. In rare cases there can be testicular injury. It’s important to consult a doctor if pain is persistent or if experiencing vomiting or fever.

Success rate

Vasectomy reversal procedures can be very successful. In 90% of cases, sperm will return and pregnancy eventuates in 50-70% of cases4. It’s important to note that the longer the time gap in between having a vasectomy and a vasovasostomy, the less fertile the male is likely to be due to the formation of sperm antibodies.

In approximately 50-75% of cases, sperm returns to ejaculate following TURED surgery5. However, pregnancy rate are low at around 25%. There can also be complications such as incontinence, recurrent blockages, and retrograde ejaculations as a result of bladder injuries.

When successful, a microsurgical vasoepididymostomy restores sperm to ejaculate in 85-90% of cases6. . Pregnancy rates vary between 50-70%.

If viable sperm is present, epididymal or testicular sperm retrieval processes can be very successful. However, pregnancy rates will be determined by the success of ARTs.

Costs

The costs of treating sperm transport obstructions or sperm retrieval procedures will vary based on where you live, the treatment required, and if you select a public or private healthcare provider. In some circumstances partial costs may be recovered. This will be assessed case-by-case and may also be based on health insurance policies.

Learn more about the cost of surgery to treat sperm transport obstructions and various epididymal or testicular sperm retrieval processes in your region.

 

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Bibliography

  1. “Pellati, D. et.al. (2008). Genital tract infections and infertility. European Journal of Obstetrices and Gynecology and Reproductive Biology. Volume 140, Issue 1, (pp. 3-11).”
  2. “Chillon, M. et al. (1995). Mutations in the Cystic Fibrosis Gene in Patients with Congenital Absence of the Vas Deferens. The New England Journal of Medicine. Volume 332, (pp. 1475-80).”
  3. “Heidenreich, A. et.al. (1994) Risk factors for antisperm antibodies in infertile men. American Journal of Reproductive Immunology, Volume 31, Issue 2, (69-76).”
  4. “Belker, A. “Microsurgical vasectomy reversal”, In: Lytton, B. et.al. eds. Advances in urology. Chicago: Year Book Medical. 1998. (pp. 193-230).”
  5. “Esteves. S. et.al. (2011). Surgical treatment of male infertility in the era of intracytoplasmic sperm injection – new insights. Clinics (Sao Paulo).Volume 66, Issue 8, (pp. 1463-77).”
  6. “Schlegel, P and Margreiter, M. (2007). Surgery for male infertility. European Association of Urology, EAU-EBU Update Series. Volume 5, (105-12).”

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