Surgical Sperm Aspiration (SSR)
What is the male reproductive system?
The organs and structures of the male reproductive system give men the ability to fertilise a woman’s egg (ovum) to produce a baby. Several different organs and structures make up the male reproductive system. These include:
The scrotum, or scrotal sac. This is the loose bag of skin which hangs under the main body cavity between the upper thighs. It is divided into two, and each side contains one testicle (testis).
The testicles (testes). There are two testes. Each is an egg-shaped structure located in the scrotum. The testes produce sperm and also produce male hormones. The testes start developing inside the body cavity in a growing baby (fetus). About two months before a male baby is born, the testes start to drop down into the scrotal sacs. Because they are outside the main body cavity the testes are slightly cooler. This difference in temperature helps sperm production.
The epididymis. This is the tube attached to the testis where sperm is stored.
The vas deferens. This is the tube which carries the sperm from the epididymis. It meets a tube from the seminal vesicle (see below) to form a short tube called the ejaculatory duct. This then opens into the urethra, which is the tube that takes the sperm outside the body.
The accessory sex glands. There are three glands which produce fluids that mix with the sperm to make up semen. Semen is the liquid which is ejected from the penis during ejaculation. The three glands are located close to the bladder and are called:
- The seminal vesicles
- The prostate gland. The prostate gland lies just beneath the bladder (see diagram). It is normally about the size of a chestnut.
- The bulbourethral glands
The penis. The penis has a single tube in it called the urethra. There are three main parts of the penis – the root, body and glans. The root is the part attached to the skin at the top of the scrotum. The body of the penis is made up of a spongy type of tissue, which swells when blood enters during an erection. The glans penis is the slightly larger area towards the end of the penis and contains the opening of the urethra.
The urethra. This is the tube which passes from the bladder down the penis to the outside. It carries both urine and semen.
What does the male reproductive system do?
The main function is to give men the ability to fertilise a woman’s egg (ovum) by producing and delivering semen. The testicles (testes) also make hormones which help men develop the characteristics associated with being male. This includes:
- The development of hair in a male distribution – for example, on the chest, under the arms, on the face and in the pubic area.
- Enlargement of the penis.
- Deepening of the voice.
- Muscle growth.
- Bone growth and increased height.
How does the male reproductive system work?
During puberty, the level of a hormone called gonadotrophin-releasing hormone (GnRH) increases. GnRH is produced in a part of the brain called the hypothalamus. In turn this causes an increase in the production of two hormones from another part of the brain, called the pituitary gland. These hormones are called luteinising hormone (LH) and follicle-stimulating hormone (FSH). LH in the bloodstream causes cells in the testicles (testes) to make and release testosterone, the main male hormone.
FSH and testosterone work together to stimulate the testes to produce sperm. Each sperm cell takes between 65-75 days to form and around 300 million are produced every day. Inside the testes sperm is made in structures called the seminiferous tubules. At the top and to the back of each testicle (testis) is the epididymis, which stores sperm.
Leading from the epididymis is the vas deferens. The vas deferens carries sperm towards the penis. Along the way it joins other tubes and during ejaculation collects fluids from the accessory sex glands. The mixture of sperm and fluids from the accessory sex glands is called semen. About two thirds of the volume of semen come from the seminal vesicles. The semen is then passed into the urethra.
When sexually aroused, a number of changes occur inside the penis. The arteries supplying the penis get bigger, allowing more blood to enter its tissues. The extra blood flow causes the penis to enlarge and to become more rigid. The extra blood flow plus signals from the nervous system and chemical changes cause an erection.
Ejaculation is the term for the contractions that release semen. This is a reflex action, which means it is not consciously controlled. As part of the reflex action, the opening that drains the bladder is closed. This means that urine is not released at the same time as semen. The volume of semen in a typical ejaculation is between 2.5-5 millilitres (mL). There are normally more than 20 million sperm in each mL of semen. During sexual intercourse, the penis of the male enters the vagina of the female, carrying the sperm to the neck of the womb (cervix) to fertilise the woman’s egg.
The epididymis is part of the male reproductive system and is present in all male mammals. It is a narrow, tightly-coiled tube connecting the efferent ducts from the rear of each testicle to its vas deferens.
Surgical Sperm Aspiration by Epididymal or Testicular Sperm Aspiraration
Mature sperm can be aspirated from the epididymis and or the testis surgically.
This is done in men who have absence of sperm (azoospermia) because of the obstruction of the tubes that carry sperm from the testis to the outside of the body (the Epididymis and the Vas Deferens).
Sperm obtained in this manner can usually only is used in a cycle of In-vitro Fertilisation (IVF) incorporating Intracytoplasmic Sperm Injection (ICSI) cycle because:
- It would be rare to obtain sperm in this way in sufficient numbers to perform simple insemination procedure.
- It is also exceptional to see sperm not bound to antibodies in these circumstances especially in men with a previous vasectomy. These antibodies restrict the ability of the sperm to fertilise the egg naturally.
IVF simply refers to fertilising the egg outside the body and ICSI involves drawing up a single sperm into a very fine glass needle and injecting it through the zona pellucida (shell of the egg) directly into the cytoplasm or centre of the egg. As the sperm are injected right inside the egg, it does not need to be very motile to fertilise the egg. In this way even with very few aspirated sperm and with very little motility we can fertilise eggs and create embryos for a pregnancy.
How and Where is the procedure performed?
- This procedure is performed under a local anaesthetic for most men especially those with failed vasectomy reversal or those with evidently blocked tubes but normal hormone levels. This is known as the PESA procedure (Percutaneous Epididymal Sperm Aspiration).
- General anaesthesia is deemed necessary usually when it is expected that PESA is less likely to be successful, on patient request or MESA/TESE is needed. For this admission to the hospital on a day case basis is arranged. The operation is carried out by a trained Surgeon, either an Urologist or Gynaecologist under sterile conditions.
PESA (Per-cutaneous Epididymal Sperm Aspiration)
This term stands for After local or a general anaesthetic, the surgeon palpates and identifies the epididymis and directs the aspiration needle directly into the epididymis.
This is always performed in the first instant and the surgeon will progress to MESA only if this procedure fails on both sides after two or three attempts on each side. Whilst undergoing this procedure under a local anaesthetic you will retain the feeling of touch but we expect that most of the pain sensation would be absent.
MESA (Microsurgical Epididymal Sperm Aspiration)
This term stands for Microsurgical Epididymal Sperm Aspiration. A cut is made into the scrotum to expose the testis and its collecting system which is known as the epididymis so the surgeon can actually see the lattice work of fine tubes inside.
These tubes, known as tubules are then aspirated using a fine needle attached to a syringe under direct vision. This fluid is then examined for the presence of viable sperm.
TESE (Testicular Sperm Extraction)
This term stands for Testicular Sperm Extraction. Unfortunately it is not always possible to retrieve sperm. If no sperm are seen in the PESA and MESA aspirates, it is usual for the surgeon to take a biopsy from the testis.
This tissue is then divided into two parts. One is sent to the laboratory for examination by the pathologist who would report on whether sperm are actually being made in the testis. The other part is dissected to see if mature sperm can be retrieved from the very tubes inside the testicular tissue directly (TESE).
About the process
- First of all we assess the sperm production within the testis and the likelihood of unsuccessful sperm retrieval by assessing your hormone levels.
- If these are normal that makes successful sperm retrieval more likely (but does not guarantee).
- In selected cases with obstructive azoospermia, in the first instance we perform the PESA procedure under local analgesia within The Centre.
- An embryologist will check the fluid aspirated from the testicular tubules. If sperm are identified, they are assessed for viability and if found suitable, they will be stored by freezing in aliquots for use in a future cycle.
- Sometimes sufficient numbers are retrieved with in the first PESA procedure to be sufficient for several treatment cycles.
- If sperm are not identified in this fluid, the MESA procedure is performed after an incision is made in the scrotal skin and the epididymis is directly exposed. This requires operating theatre’s facilities and is usually done under general anaesthesia. If the sperm are identified, they are assessed for viability and if found suitable, they will be stored by freezing for use in a future cycle.
- Freezing of live sperm does not guarantee that live sperm will definitely be available after thaw. There is always some damage to the sperm cell membrane during freezing as a result of which not all sperm will survive the freeze-thaw process.
- Occasionally when sperm survival after freeze-thaw is very poor and there is severe reduction in motility, we may perform a repeat PESA procedure on the day of egg collection especially when we know that sperm retrieval is otherwise easy.
- It will usually take about 2-3 hours to recover from your operation if performed under the general anaesthetic. Recovery after the local anaesthetic is much more rapid. You may feel bruised and possibly a little sore.
- If you have had a general anaesthetic or if you are experiencing discomfort, you will need someone to take you home and look after you that evening. It would be helpful to have some mild painkillers available at home.
- You must be prepared to stay in overnight if advised.