Testicular sperm extraction (TESE) is a surgical procedure in which a small portion of tissue is removed from the

testicle A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...

and any viable

sperm cells A spermatozoon (; also spelled spermatozoön; ; ) is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromosomes, ...

from that tissue are extracted for use in further procedures, most commonly

intracytoplasmic sperm injection Intracytoplasmic sperm injection (ICSI ) is an in vitro fertilization (IVF) procedure in which a single sperm cell is injected directly into the cytoplasm of an egg. This technique is used in order to prepare the gametes for the obtention of emb ...

(ICSI) as part of

in vitro fertilisation In vitro fertilisation (IVF) is a process of fertilisation where an egg is combined with sperm in vitro ("in glass"). The process involves monitoring and stimulating an individual's ovulatory process, removing an ovum or ova (egg or eggs) f ...

(IVF). TESE is often recommended to patients who cannot produce sperm by

ejaculation Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential component ...

due to azoospermia.''''

Medical uses

TESE is recommended to patients who do not have sperm present in their ejaculate, azoospermia, or who cannot ejaculate at all. In general, azoospermia can be divided into obstructive and non-obstructive subcategories. TESE is primarily used for non-obstructive azoospermia, where patients do not have sperm present in the ejaculate but who may produce sperm in the testis. Azoospermia in these patients could be a result of Y chromosome microdeletions, cancer of the testicles or damage to the

pituitary gland In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The hypoph ...

hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus i ...

, which regulate sperm production. Often in these cases, TESE is used as a second option, after prior efforts to treat the azoospermia through

hormone therapy Hormone therapy or hormonal therapy is the use of hormones in medical treatment. Treatment with hormone antagonists may also be referred to as hormonal therapy or antihormone therapy. The most general classes of hormone therapy are oncologic h ...

have failed. However, if azoospermia is related to a disorder of sexual development, such as

Klinefelter syndrome Klinefelter syndrome (KS), also known as 47,XXY, is an aneuploid genetic condition where a male has an additional copy of the X chromosome. The primary features are infertility and small, poorly functioning testicles. Usually, symptoms are s ...

, TESE is not used clinically; as of 2016, this was in the research phase. More rarely, TESE is used to extract sperm in cases of obstructive azoospermia. Obstructive azoospermia can be caused in a variety of ways: *

vasectomy Vasectomy, or vasoligation, is an elective surgical procedure for male sterilization or permanent contraception. During the procedure, the male vasa deferentia are cut and tied or sealed so as to prevent sperm from entering into the urethra and ...

* trauma * congenital absence of the

vas deferens The vas deferens or ductus deferens is part of the male reproductive system of many vertebrates. The ducts transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation. The vas deferens is a partially coiled tube ...

(CAVD) *

cystic fibrosis Cystic fibrosis (CF) is a rare genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. O ...

.'''' TESE can also be used as a fertility preservation option for patients undergoing gender reassignment surgery and who cannot ejaculate sperm.

Technique

Conventional TESE is usually performed under local, or sometimes spinal or general,

anaesthesia Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), a ...

. An incision in the median raphe of the

scrotum The scrotum or scrotal sac is an anatomical male reproductive structure located at the base of the penis that consists of a suspended dual-chambered sac of skin and smooth muscle. It is present in most terrestrial male mammals. The scrotum con ...

is made and continued through the dartos fibres and the tunica vaginalis. The testicle and epidydymis are then visible. Incisions are then made through the outer covering of the testis to retrieve

biopsies A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disea ...

of seminiferous tubules, which are the structures that contain sperm. The incision is closed with sutures and each sample is assessed under a microscope to confirm the presence of sperm. Following extraction, sperm is often cryogenically preserved for future use, but can also be used fresh.

Micro-TESE

Micro-TESE, or microdissection testicular sperm extraction, includes the use of an operating microscope. This allows the surgeon to observe regions of seminiferous tubules of the testes that have more chance of containing spermatozoa. The procedure is more invasive than conventional TESE, requiring general anaesthetic, and usually used only in patients with non-obstructive azoospermia. Similarly to TESE, an incision is made in the scrotum and surface of the testicle to expose seminiferous tubules. However, this exposure is much more wide in micro-TESE. This allows exploration of the incision under the microscope to identify areas of tubules more likely to contain more sperm. If none can be identified, biopsies are instead taken at random from a wide range of locations. The incision is closed with sutures. Samples are re-examined post-surgery to locate and then purify sperm. When compared with conventional TESE, micro-TESE generally has higher success in extracting sperm; as such, micro-TESE is preferable in cases of non-obstructive azoospermia, where infertility is caused by a lack of sperm production rather than a blockage. In these cases, micro-TESE is more likely to yield sufficient sperm for use in ICSI.

TESE vs TESA

TESE is different to testicular sperm aspiration (TESA). TESA is done under local anaesthesia, does not involve an open biopsy and is suitable for patients with obstructive azoospermia.

Complications

Micro-TESE and TESE have risks of postoperative infection, bleeding and pain. TESE can result in testicular abnormalities and scarring of the tissue. The procedure can cause testicular fibrosis and inflammation, which can reduce testicular function and cause testicular atrophy. Both procedures can alter the steroid function of the testes causing a decline in serum testosterone levels, which can result in

testosterone deficiency Androgen deficiency is a medical condition characterized by insufficient androgenic activity in the body. Androgenic activity is mediated by androgens (a class of steroid hormones with varying affinities for the androgen receptor), and is dependen ...

. This can cause side-effects including muscle weakness, decreased sexual function, anxiety, leading to sleep deficiency. The blood supply to the testis can also be altered during this procedure, potentially reducing supply. Long-term follow-ups are often recommended to prevent these complications. Micro-TESE has limited postoperative complications compared with TESE. The use of the surgical microscope allows for small specific incisions to retrieve seminiferous tubules and evade damaging blood vessels by avoiding regions with no vasculature. If TESE needs to be repeated due to insufficient sperm recovery, patients are usually advised to wait 6–12 months in order to allow adequate healing of the testis before further surgery.

References