Sperm Retrieval for IVF-ICSI

Updated: Oct 15, 2012
  • Author: Eric R Taylor, MD; Chief Editor: Edward David Kim, MD, FACS  more...
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Overview

Overview

Background

A variety of techniques exist for sperm retrieval for in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), including percutaneous epididymal sperm aspiration, microsurgical epididymal sperm aspiration, testicular sperm aspiration, and open testicular sperm extraction. Each procedure is associated with its own risks and benefits, but all provide similar outcomes with appropriate patient selection.

With more refined diagnostic techniques and the development of IVF, surgical sperm retrieval is now often employed as a method to provide needed sperm for IVF (fertilization of the female egg with sperm through incubation in a controlled environment outside of the body) or IVF-ICSI (the direct injection of sperm into the female egg). This technique is used when few sperm are available or sperm of low quality are used, such as in azoospermia. [1, 2]

Prior to IVF and IVF-ICSI, when only intrauterine insemination techniques were available, the harvest of intrinsically nonmotile sperm from the testicle resulted in take-home baby rates close to zero. With the advent of IVF and IVF-ICSI, it is now commonplace to achieve take-home baby rates in excess of 50%, even with nonmotile sperm obtained from testis biopsy.

The background anatomy in the images below may be helpful.

Male infertility. Hypothalamic-pituitary-gonadal a Male infertility. Hypothalamic-pituitary-gonadal axis stimulatory and inhibitory signals. Gonadotropin-releasing hormone (GnRH) from the hypothalamus stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary. FSH stimulates the Sertoli cells to facilitate sperm production, while LH stimulates testosterone release from the Leydig cells. Feedback inhibition is from testosterone and inhibin.
Male infertility. Testicular histology magnified 5 Male infertility. Testicular histology magnified 500 times. Leydig cells reside in the interstitium. Spermatogonia and Sertoli cells lie on the basement membrane of the seminiferous tubules. Germ cells interdigitate with the Sertoli cells and undergo ordered maturation, migrating toward the lumen as they mature.

Indications

Patients found to have complete absence of sperm on multiple semen analyses from either obstructive or nonobstructive azoospermia are candidates for surgical sperm retrieval. [3]

Contraindications

One exception to surgical retrieval in azoospermic men is in the setting of hypogonadotropic hypogonadism, such as a pituitary tumor. In these men, spermatogenesis is attenuated, leading to testicular hypofunction. However, it will often improve with medical treatment only, negating the need for surgical sperm retrieval.

Outcomes

Men undergoing vasectomy reversal after failed percutaneous epididymal sperm aspiration with IVF (inadequate sperm found or IVF failure) have been shown to have equivalent future success rates of vasectomy reversal compared to men not having undergone percutaneous epididymal sperm aspiration despite the theoretical risk of epididymal scarring from the procedure. [4]

Proponents of microsurgical testicular sperm extraction report increased spermatozoa detection due to the ability to identify more robust and healthy seminiferous tubules for removal. Multiple comparison studies have corroborated this, with the microdissection technique yielding roughly 20% more spermatozoa found. [5, 6, 7]

The number of biopsies performed searching for sperm is variable, but studies have shown that if sperm are present they are often found within the first four biopsies. [8, 9, 10, 11] Although on average the first four biopsies will predict successful sperm retrieval, most surgeons will still perform more than this. Risks from the surgery such as hematoma, scarring, or testicular atrophy are similar with or without the use of the microscope. However, it is felt that with the use of the microscope there is less risk of vascular damage to the tunica albuginea since vessels are more readily identified.

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Periprocedural Care

Pre-Procedure Planning

Men presenting for infertility evaluation require a thorough history and physical examination. The physician should pay close attention to the genital examination, making note of testicular size and consistency as well as any scrotal pathology, such as varicoceles. The practitioner also should explore a detailed reproductive and sexual history as it relates to infertility. All patients should provide two to three semen analyses that are then centrifuged and a basic hormone profile, including follicle-stimulating hormone (FSH) and testosterone.

Nonobstructive azoospermia is associated with an elevated FSH combined with a low testicular volume. Performance of sperm extraction at the epididymal level would likely be unsuccessful. Therefore, for this group of patients, most clinicians seek sperm at the testicular level.

Monitoring & Follow-up

The standard postoperative follow-up examination includes a focused history and detailed genital examination. Of note, serum hormonal values should be followed postoperatively, particularly in patients with nonobstructed azoospermia who underwent open testicular biopsy. Testicular scarring, inflammation, and impaired blood flow have been identified by ultrasound in up to 82% of men with nonobstructive azoospermia 3 months after testicular sperm extraction. [12] Furthermore, multiple studies have shown that the microsurgical technique also leads to testicular scarring, but it less than what is found after the standard open technique. [6, 13]

Unfortunately, both approaches may lead to a temporary decrease in testicular testosterone production. [14, 15, 16] Testicular hypofunction after micro or conventional testicular sperm extraction leading to hypogonadism can last as long as 12-18 months, but does normalize in most men after this period. [14, 15] Therefore, it is prudent to follow these men closely with serial serum hormone assays.

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Technique

Approach Considerations

All testicular biopsy techniques attempt to maximize sperm yield and minimize morbidity. Most centers attempt to freeze enough tissue vials to be able to attempt several cycles of IVF in the future.

Men with obstructive azoospermia may account for up to 40% of azoospermic men, with vasectomy representing the most common etiology. [3] Couples desiring children after vasectomy have a choice between vasectomy reversal and percutaneous epididymal sperm aspiration/testicular sperm extraction with IVF. Both are reasonable options; ultimately, factors such as cost (with and without insurance coverage), female age, number of children desired, future birth control, and other factors may help couples choose.

Patients not fit for surgical reconstruction to relieve the obstructive process or bilateral absence of the vas deferens will often first undergo attempts at sperm retrieval at the epididymal level. If sperm retrieval is unsuccessful at the epididymal level, then a testicular biopsy is necessary.

If percutaneous or microsurgical epididymal sperm aspiration is unsuccessful, testicular extraction of sperm is typically employed. This can either be done in the same setting or at a future date depending on patient and physician comfort with level of anesthesia (local with sedation is often used), availability of surgical instrumentation, and andrology laboratory factors.

In men with a nonobstructive etiology of their azoospermia, testicular extraction of sperm is necessary. The surgical procedures that exist to harvest enough sperm for IVF directly from the testicle rather than the epididymis include testicular sperm aspiration and open testicular sperm extraction. Much like microsurgical epididymal sperm aspiration, testicular sperm aspiration involves blind percutaneous sampling with the use of a large-gauge needle. It can also be employed in men with an obstructive etiology of their azoospermia.

Some advocate testicular sperm aspiration as a mapping mechanism, identifying areas of the testicle with spermatogenesis that may then be biopsied under an open technique. [17] One criticism of this aspiration technique is that studies have shown that open testicular biopsy procedures are more efficacious in men with nonobstructive azoospermia. Testicular sperm aspiration often fails to recover sperm that would be found on open biopsy. [18, 19] Another obvious criticism is that the blind technique risks damage to vascular structures with resultant bleeding. If testicular sperm aspiration fails to identify sperm, then a testicular biopsy may be performed.

Percutaneous Epididymal Sperm Aspiration

Percutaneous epididymal sperm aspiration is often the first choice in men with obstructive azoospermia because it is the least invasive option and does not require any special surgical equipment. Although percutaneous epididymal sperm aspiration in men without dilated efferent epididymal tubules will often not provide enough sperm for cryopreservation, it can provide enough sperm for fresh-cycle IVF-ICSI.

A small 30-Ga needle is inserted percutaneously into the epididymis and its contents are aspirated. If no sperm are identified, the surgeon may elect to proceed to a microsurgical epididymal sperm aspiration procedure or, more commonly, testicular sperm extraction.

Microsurgical Epididymal Sperm Aspiration

Microsurgical epididymal sperm aspiration is performed in a similar manner to percutaneous epididymal sperm aspiration, except that it uses an open incision and a surgical microscope to aid in the harvesting of sperm. Both procedures may provide enough sperm for IVF-ICSI or cryopreservation, but the microsurgical approach is more precise as the epididymis is directly visualized under magnification.

Greater precision allows for less aspiration of blood with the sample. This results in easier sperm identification and processing for both fresh and frozen samples, as well as less damage to epididymal ductules, which allows for greater preservation of native architecture.

Testicular Sperm Extraction

A testicular biopsy (or testicular sperm extraction) is executed through an open scrotal incision. It can be performed with or without the use of a surgical microscope.

The testicle is exposed and a small transverse incision is made in the anterior aspect of the tunica albuginea. Standard open testicular sperm extraction techniques may not find spermatozoa in over half of men. [19, 5, 20]

Risks from the surgery such as hematoma, scarring, or testicular atrophy are similar with or without the use of the microscope. However, it is felt that with the use of the microscope there is less risk of vascular damage to the tunica albuginea since vessels are more readily identified.

Testicular Sperm Extraction for Patients with Cancer

“Onco-TESE” describes a procedure in which a patient with cancer undergoes surgical sperm extraction. [21] Simple semen cryopreservation often suffices. However, cancer and its associated immune response, weight loss, fever, and malaise can sometimes result in samples with azoospermia or unusable severe oligospermia. [22] Additionally, sometimes male cancer patients are too sick to be able to ejaculate or are too young to have reached spermarche (the ability to ejaculate). In these cases, a testicular sperm extraction can be performed.

Previous series of onco-TESE have yielded similar success rates to men with nonobstructive azoospermia around 50%. [23] A described version of onco-TESE involves microscopic bench extraction of sperm from the normal area of testis removed for testicular cancer.

Boys around the age of spermarche can undergo simple testicular sperm extraction at the time of other procedures, such as infusion catheter placement.

If sperm is found, it is cryopreserved; if no sperm is found, some centers have implemented pilot programs to freeze small sections of testicular tissue. [24] Although no techniques currently exist to produce sperm from this spermatogonial tissue in humans, many clinicians are optimistic that it is only a matter of time before science is able to do so. Indeed, this was very recently achieved in rats and normal offspring were produced. [25]

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