Sperm Retrieval Techniques

Sperm Retrieval Techniques



Azoospermia is defined as the complete absence of sperm in the ejaculate after analysis of two ejaculated specimens. Up to 15% of infertile men are azoospermic, and the etiology can be either obstructive azoospermia (OA) or nonobstructive azoospermia (NOA). OA is estimated to be responsible for 40% of cases of azoospermia and can result from such varied causes as congenital absence of the vas deferens or ejaculatory duct obstruction and iatrogenic etiologies such as vasectomy, injury to the vasa during inguinal surgery, or injury to the epididymis from scrotal surgeries such as hydrocelectomy. NOA comprises the remaining cases and results from failure of the testis to produce sperm. It is imperative that the clinician determine through careful history and exam if the cause is lack of sperm production or obstruction because this will dictate the optimal approach for sperm retrieval. For NOA, only the testis can be targeted for retrieval purposes; however, with OA, the vas deferens, epididymis, and/or testis can likely be used.

OA can be suspected based on history (prior vasectomy or bilateral inguinal surgeries), physical exam (normal testicular volume [>20 mL], absent vasa, or congested epididymides), and laboratory values (normal follicle-stimulating hormone [FSH] [<8 mIU/mL], positive serum antisperm antibody assay, or decreased ejaculate volume [<1.5 mL]) (1). NOA can similarly be suspected based on history (known hypogonadism), physical exam (atrophic testis), and laboratory values (FSH elevated 2 to 3 times upper limit of normal, negative antisperm antibody assay, karyotype anomalies, or Y chromosome microdeletions). In addition, men with ejaculatory dysfunction such as anejaculation or retrograde ejaculation are also candidates for epididymal sperm retrieval, although some of these men may also use less invasive sperm retrieval techniques such as penile vibratory stimulation, electroejaculation, or postejaculatory urine sperm retrieval depending on the etiology of their aspermia. Furthermore, men with obstruction may benefit from reconstruction, particularly if more than one biologic child is desired, because primary reconstruction is more cost-effective than sperm retrieval and repeated in vitro fertilization (IVF) cycles. If the female partner, however, has fertility issues that necessitate IVF and intracytoplasmic sperm injection (ICSI), surgical sperm retrieval may be more appropriate than reconstruction.

There are expected differences in the quality and quantity of spermatozoa retrieved based on the etiology of azoospermia, method of recovery, and tissue of origin. Epididymal sperm is often more mature and motile, whereas testicular sperm is usually immotile except in the case of obstruction. Notably, the virtually limitless supply that is recovered with microsurgical epididymal sperm aspiration (MESA) allows multiple samples that can be frozen for future IVF cycles and has a distinct advantage over the more limited numbers harvested from testicular tissue. The sperm retrieval can be done any time prior to the IVF cycle with multiple vials cryopreserved. Percutaneous epididymal sperm aspiration (PESA) generally has a relatively low yield of sperm, most of which are severely damaged with low motility. Percutaneously retrieved sperm with very poor motility may reduce IVF success rates, and low sperm motility may adversely affect the ability to freeze sperm for future use. Patients should be counseled accordingly regarding this possibility.

Sperm retrieval from men with impaired sperm production (NOA) for use with assisted reproductive technology (ART) is preferentially performed the day before oocyte retrieval, although it can be performed the same day if necessary. Timing is important because all methods of sperm retrieval commit the female partner to ART, and the female can be spared an unnecessary procedure if no sperm are found and the couple defers the use of donor sperm. It is recommended that surplus sperm be frozen for potential use in the future so as to spare the male partner additional procedures. Although it is understood that there is an expected loss of up to half of the frozen spermatozoa during the freeze-thaw process, there is no data to suggest that the sperm which survive the freeze-thaw process are inferior to fresh sperm. In fact, there seems to be no difference in either the fertilization or pregnancy rate from fresh or frozenthawed sperm when men have normal sperm production and are obstructed (2). For men with normal production and obstruction, elective sperm retrieval for freezing prior to the IVF/ICSI cycle may be preferred. For men with NOA, best results are obtained fresh sperm.

Contraindications to sperm retrieval efforts include anyone who cannot undergo scrotal surgery such as men with active groin or urinary infections or men who are not physically able to withstand the stress of surgery. Retrieval is not recommended for men with complete deletions of the AZFa or AZFb regions of the Y chromosome because no patients have had sperm found with these conditions. Relative contraindications include men who have already undergone a failed, thorough bilateral microscopic-assisted testicular sperm extraction (microTESE) by a trained microsurgeon because the chance of successful sperm retrieval in these men is virtually zero.


All methods of sperm retrieval warrant evaluation under phasecontrast microscopy during the procedure in order to document if sperm have been retrieved and degree of motility. Additional
pathologic evaluation of a permanent specimen or analysis by an andrology laboratory does not replace the real-time information which can be obtained from a properly performed intraoperative wet prep. In the case of testis biopsy, a touch prep is prepared by gently touching a slide to the cut surface of the testis, adding a drop of human tubal fluid (HTF) media. For epididymal aspirations, a tiny drop of aspirated specimen is placed on a slide, mixed with HTF, and for TESE specimens, after complete tissue dispersion of the retrieved sample by the urologist, a small fraction of tissue is placed on a slide. After a drop of HTF is added, a cover slip is carefully placed. Analysis under a microscope at 400× magnification will not only reveal the presence or absence of sperm but motility can be assessed as well. The presence of many motile or immotile sperm in the testis or in the epididymal fluid confirms the diagnosis of OA in men who are candidates for reconstruction (3). The identification of adequate (enough to fertilize all retrieved oocytes), viable (at least twitching) sperm during a TESE procedure signifies success, and the procedure can be terminated.

A permanent, fixed touch prep is a second kind of specimen evaluation that is most useful in men with NOA. After touching a slide to the cut surface of the testis, it is fixed with 95% ethyl alcohol and stained with the Papanicolaou technique. This technique is specifically used to differentiate between late maturation arrest and complete spermatogenesis. It allows the pathologist to scan through multiple depths of the specimen to identify if the spermatozoa have developed tails or not. Traditional permanent section of biopsy specimens uses such thincut paraffin embedded specimens that pathologists are unable to identify if the spermatozoa have tails, and thus, they cannot differentiate between late maturation arrest and complete spermatogenesis without the aid of touch preps.


Intratubular Germ Cell Neoplasia

One admittedly controversial indication for testicular biopsy is in men at increased risk of testicular cancer or intratubular germ cell neoplasia (ITGCN). These include men who have a history of male factor infertility, cryptorchidism, contralateral testicular cancer, and atrophic testis (<12 mL) and patients with disorders of sex development (5). Men who are undergoing orchiectomy for testicular cancer can consider concomitant contralateral testicular biopsy because up to 9% of these men will have ITGCN in the contralateral testicle (6). Prepubescent boys undergoing orchidopexy do not warrant biopsy because of the rarity with which ITGCN is found, although adult males undergoing orchidopexy for undescended testis should consider it because 1.7% of men with a history of cryptorchidism are found to have ITGCN. The pathologic finding of ITGCN lends itself to additional controversy because there is no gold standard for management. Although 70% of men with ITGCN will develop a germ cell tumor within 7 years, immediate treatment is not always required. Radical orchiectomy is typically done for men with ITGCN and a contralateral normal testicle. Radiation therapy is considered for men with a solitary testicle to preserve androgen production.

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Apr 24, 2020 | Posted by in UROLOGY | Comments Off on Sperm Retrieval Techniques
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