Table of ContentsView AllTable of ContentsAnatomyFunctionAssociated ConditionsDiagnosis
Table of ContentsView All
View All
Table of Contents
Anatomy
Function
Associated Conditions
Diagnosis
The vas deferens (also called the ductus deferens or sperm ducts) are an important part ofmale reproductive anatomy. These paired tubes function to move sperm away from its storage place in the testicle to theurethrawhere it leaves the body during ejaculation.
The vas deferens are cut during avasectomy(male surgical sterilization) to prevent sperm from leaving the body during intercourse and fertilizing an egg, leading to pregnancy.
This article will briefly take you through the anatomy and function of the vas deferens, conditions that may affect them, and how problems are diagnosed.
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Anatomy of the Vas Deferens
The vas deferens transport mature sperm to the urethra before ejaculation. They are best described as a pair of hard, thick-walled, muscular tubes. These two tubes are identical and are each up to approximately 18 inches (45 centimeters) long.
The vas deferens begin at theepididymis(where sperm is stored after it is made in the testes). From the epididymis, the vas deferens extend through the pelvis to the bladder. Here the two tubes branch off, forming two storage chambers for semen that attach to the left and right walls of the bladder. The storage chambers join up with the ejaculatory ducts which connect them to the urethra.
The actual structure of the vas deferens has three layers. The outermost layer (adventitia) is made of connective tissue.Beneath this layer is the muscular coat which consists of various layers of muscle fibers. The innermost layer (the mucous coat) is lined with columnar epithelial cells.
Anatomical Variations
While rare, it is possible to be born without vas deferens—a condition that causes infertility. The congenital absence of the vas deferens can occur alone but is often associated with another genetic condition calledcystic fibrosis. While males who are born without the vas deferens are typically infertile the condition does not affect their sex drive or ability to have sex.
Some people with congenital absence of the vas deferens can father children with the assistance of reproductive technology.
The Function of the Vas Deferens
As previously mentioned, the main function of the vas deferens is to carry sperm—the term “vas deferens” meanscarrying-away ductin Latin.
Associated Conditions of the Vas Deferens
Obstructive Azoospermia
Obstructiveazoospermiais a condition where either the vas deferens, the epididymis, or the ejaculatory ducts are blocked or obstructed preventing sperm from traveling properly along its normal route to leave the body.
Typical causes of obstruction may include congenital deformities (congenital absence of the vas deferens is actually a form of obstructive azoospermia), trauma, injuries, or complications from surgeries includinghernia repairor vasectomy. Sometimes these obstructions can be surgically corrected to restore the proper flow ofsperm and fertility.
Inflammation
Inflammation of the vas deferens is a rare condition sometimes referred to as vasitis. It often occurs after a vasectomy in which case it may cause no symptoms other than a palpable mass in the vas deferens. This mass may not necessitate any treatment but may need to be biopsied to confirm that it is benign (harmless).
Vasectomy
A vasectomy is a common surgical procedure that involves closing off the vas deferens as a means to render a man sterile. It is one of the most widely used forms of male contraception available.
This procedure is often done in a healthcare provider’s office or a surgical center under local anesthesia. A specialist called a urologist often performs the surgery although other healthcare providers can be qualified to do so as well.
Vasectomies result in infertility in more than 99% of men who undergo the operation.Over 500,000 vasectomies are performed in the U.S. yearly. This makes it the fourth most common form of contraception.
While vasectomies are intended to cause permanent sterilization, they can occasionally bereversed with surgery(vasovasostomy). They can also, on occasion, fail as the vas deferens can reconnect (called recanalization).
Until a positive confirmation of sterility comes back from the laboratory, backup contraception must be used. This usually takes at least three months.
Risks of a vasectomy include a negative reaction to the anesthetic medication, bleeding, infection at the site of the incision (or puncture), recanalization,hematoma, and sperm granuloma (a small mass or lump that develops slowly due to inflammation following a vasectomy).
Diagnosing the Vas Deferens
Semen analysis may be done to check for male fertility and blockages of the vas deferens. This test will include the volume, number of sperm per milliliter, percentage of motile sperm, the shape of the sperm, and the presence of white blood cells.A semen culture may be performed to check for infection or inflammation.
Imaging may be done to look for conditions affecting the vas deferens, including ultrasound, computerized tomography (CT), or magnetic resonance imaging (MRI).In the case of a suspected malignancy, a biopsy may be performed.
Summary
The vas deferens (aka the ductus deferens or sperm ducts) are paired tubes that move sperm from the testicle to the urethra during ejaculation. The primary function of the vas deferens is to carry sperm, a process that begins with penile erection and ends with ejaculation.
These tubes are cut or closed off during a vasectomy. Post-vasectomy, semen must be tested periodically to make sure that no sperm is present or motile. Vasectomies come with certain risks including bleeding, infection at the site of the incision, recanalization, and chronic pain.
Semen analysis/cultures and various imaging techniques are used to assess/diagnose issues with male fertility and blockages of the vas deferens.
What Is a No-Scalpel Vasectomy?
10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Phillips E, Carpenter C, Oates RD.Ejaculatory dysfunction.Urol Clin North Am. 2014;41(1):115-128. doi:10.1016/j.ucl.2013.08.018IMAIOS.Vas deferens.MedlinePlus.Congenital bilateral absence of the vas deferens.MedlinePlus.Sperm release pathway.Stanford Health Care.What is azoospermia.Ayed A, Alshahrani AM.What You Should Know About Vasitis: A Case Report.Cureus. 2024;16(4):e58785. Published 2024 Apr 22. doi:10.7759/cureus.58785Amory JK.Male contraception.Fertil Steril. 2016;106(6):1303‐1309. doi:10.1016/j.fertnstert.2016.08.036UpToDate.Vasectomy.American Urological Association.Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline (2020).American Association for Clinical Chemistry.Semen analysis.
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Phillips E, Carpenter C, Oates RD.Ejaculatory dysfunction.Urol Clin North Am. 2014;41(1):115-128. doi:10.1016/j.ucl.2013.08.018IMAIOS.Vas deferens.MedlinePlus.Congenital bilateral absence of the vas deferens.MedlinePlus.Sperm release pathway.Stanford Health Care.What is azoospermia.Ayed A, Alshahrani AM.What You Should Know About Vasitis: A Case Report.Cureus. 2024;16(4):e58785. Published 2024 Apr 22. doi:10.7759/cureus.58785Amory JK.Male contraception.Fertil Steril. 2016;106(6):1303‐1309. doi:10.1016/j.fertnstert.2016.08.036UpToDate.Vasectomy.American Urological Association.Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline (2020).American Association for Clinical Chemistry.Semen analysis.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Phillips E, Carpenter C, Oates RD.Ejaculatory dysfunction.Urol Clin North Am. 2014;41(1):115-128. doi:10.1016/j.ucl.2013.08.018IMAIOS.Vas deferens.MedlinePlus.Congenital bilateral absence of the vas deferens.MedlinePlus.Sperm release pathway.Stanford Health Care.What is azoospermia.Ayed A, Alshahrani AM.What You Should Know About Vasitis: A Case Report.Cureus. 2024;16(4):e58785. Published 2024 Apr 22. doi:10.7759/cureus.58785Amory JK.Male contraception.Fertil Steril. 2016;106(6):1303‐1309. doi:10.1016/j.fertnstert.2016.08.036UpToDate.Vasectomy.American Urological Association.Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline (2020).American Association for Clinical Chemistry.Semen analysis.
Phillips E, Carpenter C, Oates RD.Ejaculatory dysfunction.Urol Clin North Am. 2014;41(1):115-128. doi:10.1016/j.ucl.2013.08.018
IMAIOS.Vas deferens.
MedlinePlus.Congenital bilateral absence of the vas deferens.
MedlinePlus.Sperm release pathway.
Stanford Health Care.What is azoospermia.
Ayed A, Alshahrani AM.What You Should Know About Vasitis: A Case Report.Cureus. 2024;16(4):e58785. Published 2024 Apr 22. doi:10.7759/cureus.58785
Amory JK.Male contraception.Fertil Steril. 2016;106(6):1303‐1309. doi:10.1016/j.fertnstert.2016.08.036
UpToDate.Vasectomy.
American Urological Association.Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline (2020).
American Association for Clinical Chemistry.Semen analysis.
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