Published: 18 Jun 2025

ICD9: 606.0      ICD10: N46.01      ICD11: GB04

Obstructive azoospermia is a type of male infertility characterized by the absence of sperm in the ejaculate (azoospermia) due to a physical blockage or obstruction in the male reproductive tract.
Despite the absence of sperm in the ejaculate, sperm production in the testicles is normal. The problem lies in the inability of the sperm to travel from the testicles, where they are produced, to the urethra and out of the body during ejaculation.

Here's a more detailed breakdown:

Azoospermia: This means "no sperm" in the semen. A normal semen analysis should show the presence of motile sperm cells.
Obstructive: This indicates that there is a physical blockage or barrier preventing sperm from reaching the ejaculate. This distinguishes it from non-obstructive azoospermia, where the testes aren't producing enough (or any) sperm.
Location of Obstruction: The blockage can occur at various points in the male reproductive tract:
Epididymis: The most common site. The epididymis is a coiled tube attached to the testicle where sperm mature and are stored. Blockages here can result from infection, inflammation, or congenital defects.
Vas Deferens: The tube that carries sperm from the epididymis to the ejaculatory ducts. Obstructions can result from vasectomy (intentional blockage for contraception), injury, infection, or congenital absence (Congenital Bilateral Absence of the Vas Deferens - CBAVD, often associated with cystic fibrosis gene mutations).
Ejaculatory Ducts: These ducts carry sperm and seminal fluid into the urethra. Blockages here can result from infection, scarring, or cysts.

Causes of Obstructive Azoospermia:

Vasectomy: The most common *intentional* cause.
Congenital Bilateral Absence of the Vas Deferens (CBAVD): A genetic condition often associated with cystic fibrosis gene mutations. Men with CBAVD are born without vas deferens.
Infection/Inflammation: Epididymitis (inflammation of the epididymis) or other infections can cause scarring and blockage. Sexually transmitted infections (STIs) like gonorrhea and chlamydia can sometimes lead to this.
Injury/Trauma: Injury to the scrotum or groin area can damage the reproductive tract and cause obstruction.
Surgery: Previous surgery in the groin or pelvic region can sometimes damage the reproductive tract.
Cysts/Tumors: Rarely, cysts or tumors can press on or block the reproductive tract.
Inguinal Hernia Repair: Can sometimes damage the vas deferens.

Diagnosis:

Semen Analysis: Shows azoospermia (absence of sperm).
Physical Examination: To check for abnormalities in the testes, epididymis, and vas deferens.
Hormone Levels (FSH, LH, Testosterone, Prolactin): These are typically normal in obstructive azoospermia, helping to differentiate it from non-obstructive azoospermia. Elevated FSH levels often suggest testicular failure (non-obstructive).
Genetic Testing: Especially if CBAVD is suspected (e.g., cystic fibrosis gene mutation testing).
Transrectal Ultrasound (TRUS): To evaluate the prostate and seminal vesicles and identify ejaculatory duct obstructions.
Vasography: An X-ray procedure where dye is injected into the vas deferens to visualize the reproductive tract and identify blockages. Less commonly used now.
Testicular Biopsy: May be performed to confirm normal sperm production in the testicles.

Treatment Options:

The treatment options depend on the location and cause of the obstruction. They typically involve either surgically correcting the obstruction or retrieving sperm directly from the testicles or epididymis for use in assisted reproductive technologies (ART) such as in vitro fertilization (IVF).

Surgical Reconstruction:
Vasectomy Reversal (Vasovasostomy): Reconnects the vas deferens after a vasectomy.
Vasoepididymostomy: Connects the vas deferens directly to the epididymis if the blockage is in the epididymis.
Transurethral Resection of the Ejaculatory Ducts (TURED): Surgical procedure to open blocked ejaculatory ducts.
Sperm Retrieval Techniques (used with IVF):
Microsurgical Epididymal Sperm Aspiration (MESA): Sperm are aspirated from the epididymis using a microscope.
Testicular Sperm Extraction (TESE): Sperm are extracted directly from the testicles through a small incision.
Percutaneous Epididymal Sperm Aspiration (PESA): Sperm are aspirated from the epididymis using a needle inserted through the skin.
Testicular Sperm Aspiration (TESA): Sperm are aspirated from the testicle using a needle inserted through the skin.

Important Considerations:

The success rates of surgical reconstruction and sperm retrieval vary depending on the cause of the obstruction, the location of the blockage, the technique used, and the skill of the surgeon.
If surgical reconstruction is successful, the man may be able to conceive naturally. If not, or if sperm retrieval is used, IVF with intracytoplasmic sperm injection (ICSI) is typically necessary. ICSI involves injecting a single sperm directly into an egg to achieve fertilization.
Genetic counseling is important, especially if CBAVD is suspected, to discuss the risk of the child inheriting the cystic fibrosis gene mutation.

In summary, obstructive azoospermia is a potentially treatable cause of male infertility where sperm are produced but cannot be ejaculated due to a blockage. Diagnosis involves semen analysis, physical examination, hormone testing, and possibly imaging or genetic testing. Treatment options include surgical reconstruction or sperm retrieval for use with assisted reproductive technologies.