Vasectomy for Male Sterilization

A vasectomy is a surgery that works to inhibit reproduction by interrupting the passage of sperm through the vas deferens, a tube in the male reproductive system. The procedure is a method of inhibiting an individual’s ability to cause pregnancy through sexual intercourse without altering the other functions of the penis and testes. In the US, into the early 1900s, proponents of eugenics, the belief that human populations can be made better by selecting for so-called desirable traits, used the procedure to forcibly sterilize people whom they deemed undesirable. Despite its early associations with eugenics, physicians’ use of vasectomy eventually transitioned into an option for elective contraception. Even with the various shifts in motivation for performing vasectomies, as of 2024, individuals have the choice to undergo a sterilization procedure if they want to restrict their own ability to have children.

1. Relevant Anatomy
2. History of the Procedure
3. Eugenic Applications
4. Vasectomy as Birth Control

Relevant Anatomy

The goal of a vasectomy is blocking the passage of sperm through the vas deferens. Sperm are male reproductive cells that can fuse with egg cells, or female reproductive cells, in the process of fertilization. When fertilization occurs, pregnancy can begin, and an embryo starts to form. One of the functions of the testes, which hang in a structure called the scrotum below the penis, is to generate sperm. Once sperm form in the testes, they move to a tube called the epididymis. The epididymis connects to the vas deferens, a tube between thirty and thirty-five centimeters in length that extends from the epididymis in the scrotum up into the pelvis. Typically, there are two vasa deferentia that extend from each testis and meet at a structure called the ejaculatory duct. The vas deferens transports the sperm past a gland called the seminal vesicle and then past the prostate gland inside of the pelvis, both of which help generate a fluid called semen to aid the transport and protection of sperm cells. The vas deferens facilitates the overall transport of sperm from where it forms to the ejaculatory duct, which allows the penis to release the semen containing sperm during ejaculation.

Due to its role of transporting sperm, the vas deferens is a convenient focus for surgical procedures meant to sterilize an individual. Despite differences in specific methods, all vasectomies follow the same general path. The first necessary step is gaining access to the vas deferens. A surgeon, typically by incision or puncture, creates an opening on the scrotum to access the vas deferens. Once the surgeon has cut through or punctured the skin of the scrotum, it is up to their choice of method to stop the flow of sperm through the vas deferens. The surgeon may cut, tie, burn, or use any combination thereof to interrupt the vas deferens’ ability to let sperm travel through it.

History of the Procedure

Some of the first writings on the male reproductive system date all the way back to ancient Greece, but Rufus of Ephesus, a physician from Greece that lived from 70 AD to 110 AD, was one of the first to mention the vas deferens, in his book De nominatione partium hominis (On the Naming of the Parts of the Body). He created the text to have exact names for various body parts to prevent misunderstandings, but other anatomists ended up calling the vas deferens by different names such as evacuatorium until around the Renaissance. According to Yefim R. Sheynkin, a physician who practices and researches urology in Long Island, New York, the term vas deferens supposedly originated with an anatomist from Bologna, Italy, named Mondino dei Liuzzi. The term vas deferens comes from Latin, with vas meaning duct or vessel and deferens coming from a verb meaning to carry away. In 1316, dei Liuzzi published an anatomical textbook called De Anatome, frequently called Anothomia, in which he discusses the role of the vas deferens in carrying seminal fluid away from the testes. At the time, dei Liuzzi knew about the transport functions of the vas deferens but not the details or function of semen.

Centuries later, in 1668, Regnier de Graaf, a physician from the Netherlands, published one of the first comprehensive investigations of the anatomy of the vas deferens. He compared the vas deferens to a large nerve with a cavity running through it. De Graaf performed experiments on animals where he tied closed the vas deferens before sexual activity. He reported that the testicular ends of the vas deferens swelled with fluid, clarifying that the testes form semen, and the vas deferens assist in its movement out of the body. In 1677, not long after de Graaf’s publications, researcher Antoni van Leeuwenhoek, a microscope and microscope lens manufacturer who studied microscopic life and was also from the Netherlands, reported one of the first descriptions of sperm. According to Stuart S. Howards, a urologist and researcher, who as of 2023, is working in Winston-Salem, North Carolina, Johan Ham, a medical student at the time, conveyed to Leeuwenhoek that he found little animals in the semen he was observing, and thought they may have appeared due to decay. After observing it himself, Leeuwenhoek instead inferred that what Ham saw was a typical part of semen. Leeuwenhoek’s reports of the presence of individual cells in semen enabled future researchers to understand sperm as individual, motile cells that are necessary for fertilization and, therefore, human reproduction.

After the discoveries of de Graaf and van Leeuwenhoek, it took nearly two centuries for scientists and physicians to begin to manipulate the vas deferens for medical purposes. Prior to the use of vasectomy, castration was the primary method for surgically interfering with the male reproductive system. Castration involves the removal of the testes or severing the supply of blood to the testes, which causes them to atrophy and shrink.

Astley Cooper, a surgeon who studied anatomy in the United Kingdom, performed the first reported vasectomy on a dog in the early 1800s. In that procedure, he closed off the vas deferens to interrupt the flow of sperm through it, leaving the blood supply to the testes intact. He reported that, unlike with castration, the vasectomy did not result in the decay of the testes. After ligation, or closing off the tubes, Cooper observed that the epididymis and testes became enlarged. Additionally, Cooper found that, six years after the procedure, the epididymis still contained intact sperm. That allowed Copper to confirm that the testes still produce sperm despite the interruption in flow through the vas deferens. Further research from other scientists throughout the rest of the early 1800s confirmed Cooper’s conclusion that vasectomy stops the flow of sperm without stopping its production in the testes.

Across parts of Europe and the US, the surgeons who first performed vasectomies on humans around the 1880s were aiming to treat patients with enlarged prostate glands rather than using the procedure for sterilization. Enlargement of the prostate often occurs in older patients, who typically experience discomfort, and may have difficulty urinating or need to urinate excessively. One surgeon who published his work performing vasectomies to treat an enlarged prostate during that time period was Reginald Harrison, who often worked in Liverpool, England, and London, England. He conducted over 100 vasectomies between 1893 and 1900. Harrison reported that severing the vasa deferentia would cause patients’ enlarged prostate glands to shrink. It also restored the patient’s ability to urinate regularly. However, with time, reports began to conflict with Harrison’s and others’ reports on the consistency of vasectomy as an effective method for prostate treatment. By the end of the nineteenth century, surgeons had all but abandoned vasectomy in favor of other surgical prostate procedures.

Despite disagreement about its efficacy and eventual abandonment, vasectomy for prostate treatment allowed surgeons to experiment with different techniques both for accessing the vas deferens inside of the scrotum and for blocking the flow of sperm through the tube. One of the first improvements of the surgery, called the “English method,” was choosing the scrotum as the location for incision rather than the inguinal approach. In the inguinal approach, the physician makes an incision towards the lower abdomen instead of on the scrotum. Throughout his career, Harrison in particular had developed two techniques for interrupting sperm flow through the vas deferens. He began by making two incisions on the scrotum to access two different points on the vas deferens, so he could cut and remove a portion of the tube. Harrison would then ligate the severed ends of the tubes. Another method Harrison developed was to only use one incision paired with twisting the vas deferens to create a block, which required no tying. Additionally, in 1900, Harrison reported one of the first known cases of the vas deferens spontaneously reconnecting after the surgery. He observed that a patient’s vas deferens reconnected, allowing sperm to flow freely through it, indicating that the effects of the surgery were not permanent in certain cases.

Eugenic Applications

In the 1890s, focus began to move toward the contraceptive capacities of vasectomy procedures, primarily motivated by goals of eugenics. In 1899, Harry Sharp, a prison physician in Indiana, performed the first reported vasectomy meant to sterilize an individual, rather than treat a medical condition, like an enlarged prostate. Sharp performed the procedure on an inmate at the Indiana State Reformatory in Jeffersonville, Indiana, reporting that he meant to treat the inmate’s excessive masturbation. Sharp analyzed the inmate’s semen samples after the procedure and reported that no sperm were present in the fluid. Sharp used a method called an open-end vasectomy, which involves tying off only the ends of the vasa deferentia segments that lead up into the pelvis, allowing the testicular segments to release sperm through their unobstructed ends. Sharp eventually adopted the “English method,” making incisions directly into the scrotum, after the method grew in popularity. Continuing into the early 1900s, Sharp was able to promote vasectomies as Indiana was passing laws that promoted eugenic ideals, such as forcing sterilization on those whom the government deemed unfit. Sharp’s introduction of vasectomies to sterilize people, along with his subsequent procedures on more inmates, led to vasectomies being paired with eugenics.

Since vasectomy makes a individual sterile while preserving normal bodily functions, the procedure became an easy and purportedly humane method to sterilize people whom Sharp and other eugenicists deemed unfit. By 1909, a decade after the first vasectomy Sharp performed, he had used the surgery to sterilize 280 people. Though Sharp reported that his patients sought out the procedure, modern historians and researchers such as Alexandra Minna Stern have concluded that Sharp did not obtain valid consent from certain parties, such as those with mental disabilities. Additionally, those historians and others have inferred that Sharp’s stated goal of treating his patients’ health was secondary to the goal of further punishing prisoners and keeping people whom he viewed as undesirable from being able to reproduce. Then in 1910, Sharp wrote and presented the “The Indiana Plan” to the National Prison Association. In his work, he continued to promote the use of vasectomies, especially as a way to prevent passing down heritable disorders, and to ease sexual disorders, further promoting his eugenicist beliefs.

Vasectomy as Birth Control

Vasectomy’s transition from a method of eugenic sterilization to elective birth control was not a clear switch. In the early 1900s, surgeons William Belfield and Vincent O’Connor, both from the US, published material urging men with chronic mental or physical illnesses to voluntarily seek out vasectomy so that they would not pass those traits on to their children. Though still based in the eugenicist ideas of prohibiting people with heritable illnesses or traits deemed otherwise socially unacceptable, Belfield and O’Connor were some of the first physicians to promote individuals making their own choices in restricting their own fertility. During the shift in the goals of vasectomy as a sterilization procedure, in 1924, Harry Rolnick, a surgeon working in the US, performed vasectomies on twenty-five dogs and confirmed Harrison’s 1900 report of a severed vas deferens healing. Rolnick’s confirmation led to several innovations in vasectomy technique to prevent the reconnection of the cut tubes.

Surgeons then looked to modify vasectomy procedures to reduce the risk of the patient regaining fertility over time. In 1937, Joseph E. Strode, a physician and researcher working in the US, created a technique that relies on burying the testicular end of the severed vas deferens in the tissue that surrounds the tube while leaving the abdominal end outside of the tissue. The method puts in place a physical barrier that mitigates the chance of the severed segments of the vas deferens reconnecting. Stanwood Schmidt, a urologist working in US, published a new technique of interrupting sperm flow through the vas deferens in 1966. His method involved electrically cauterizing, or burning, a small point of the cut vas deferens to form scar tissue that blocks the flow of sperm through the tube.

During the period of innovations in vasectomy technique, the surgery was beginning to gain traction as a voluntary contraceptive procedure in parts of Asia. Beginning in 1952, the government of India created programs to encourage young men to get vasectomies as a means of population control. They appealed to men through various means such as vasectomy camps and festivals where physicians could perform massive volumes of vasectomies in short amounts of time. Thailand followed with similar efforts and mass vasectomies were conducted at special festivals held on the King of Thailand’s birthday. Particularly in India, the promotion of vasectomy became more coercive in the 1970s, with financial incentives for vasectomy providers and patients that were higher than each person’s monthly salary. Towards the late 1970s, according to Sheynkin, the Indian government had rolled back their family planning program due to reactions against the coercive vasectomy program, and instead focused on female sterilization.

The population concerns in Asian countries during the 1960s and 1970s spurred another innovation in vasectomy technique, the no-scalpel vasectomy. During that time, Li Shunqiang, a surgeon who was working at the Chongqing Family Planning Scientific Research Institute in the Sichuan province of China, developed a new technique for accessing the vas deferens to perform a vasectomy. Called no-scalpel vasectomy, or NSV, Li’s technique relies on using specialized surgical instruments to grasp the vas deferens through the skin of the scrotum and puncture the skin to access the tube. NSV does not require a surgical knife to cut into the scrotum or stitches after the surgery. Additionally, the time required for the operation is shorter, and patients generally report less pain and swelling after the procedure. The ease of Li’s NSV technique relative to other methods of vasectomy has allowed it to gain popularity in China as well as the US since its invention.

After the introduction and spread of Li’s NSV technique, there have not been many major innovations in the ways that surgeons perform vasectomies. During the second half of the twentieth century and the start of the twenty-first century, there were studies on reversible methods of blocking the flow of sperm through the vas deferens, specifically with regard to implants that could be removed at a later time. One such implant, called the VasClip, received approval from the US Food and Drug Administration in 2002. However, the device had high rates of failure and its manufacturers stopped producing it soon after. Since the early 2000s, researchers have looked into even less-invasive methods of performing vasectomies including vasectomies via focused ultrasound waves and lasers.

In tandem with developments in performing contraceptive vasectomies, researchers have also been researching how to perform vasectomy reversals. The first instance of vasectomy reversal occurred in 1902, when Edward Martin, a surgeon working at the University of Pennsylvania in Philadelphia, Pennsylvania, performed a surgery that restored sperm travel through the vas deferens by connecting a severed portion of the vas deferens to the epididymis. That procedure is called vasoepididymostomy. In his use of it, Martin’s procedure was not reversing a vasectomy, but it has grown to be one of two primary methods for restoring a individual’s fertility. The other method of surgical vasectomy reversal involves reconnecting the two severed ends of the vas deferens after a surgeon removes the blocked portion. The procedure, called a vasovasostomy, first came about in 1919 in the US with a surgeon named William C. Quinby. Both procedures continued in their use across the twentieth century. Vasovasostomy in particular developed further as a microsurgery in the latter half of the twentieth century. The surgeon performing the microsurgery procedure uses a surgical microscope and extremely small equipment to make the reconnection of the vas deferens as watertight as possible without causing unnecessary trauma to the tissue.

Annually, about 500,000 patients get a vasectomy in the US. Evolving through stages of experimental prostate treatment and forced eugenic sterilization, vasectomy is now a widely used method of long-term contraception that allows individuals with male reproductive systems to better control their own fertility.