Surgical Procedures for Male Infertility: An Update

William R. Visser; L.I. Smith-Harrison; Sarah C. Krzastek

Disclosures

Curr Opin Urol. 2021;31(1):43-48. 

In This Article

Sperm Retrieval

Epididymal Sperm Aspiration

Since the development of assistive reproductive technologies, sperm retrieval has been a crucial element in the infertility specialist's toolbox. Microsurgical epididymal sperm aspiration (MESA) is the gold standard procedure for sperm retrieval with a sperm retrieval rate of greater than 95%, and is the preferred method as it can yield millions of motile sperm with little to no blood contamination.[33,34] Patients are typically placed under general anesthesia, although regional anesthesia is possible. Incision can be made in a vertical or horizontal fashion through the skin and dissection is carried down through the dartos fascia and the tunica vaginalis. The testis and epididymis are then delivered and inspected. The surgeon should look for dilated tubules containing golden, semitranslucent fluid, which can typically be found in the caput epididymis.[33] The overlying epididymal tunic is carefully incised with meticulous use of bipolar electrocautery to maintain hemostasis. An ophthalmic microknife is used to sharply puncture the dilated epididymal tubules. Fluid is then expressed from the tubules and collected. The fluid should be evaluated in real-time by the surgical team or a qualified embryologist that is on site. If motile sperm is not identified in the specimen, then a new epididymal tubule should be located and incised with repeat microscopic analysis. Once adequate sperm are collected, the epididymal tubule is closed with bipolar electrocautery and the tunica vaginalis is closed with an absorbable suture. If sperm cannot be retrieved by MESA, then the surgeon may elect to retrieve sperm directly from the testis. Sperm isolated using the MESA approach are superior to sperm obtained directly from testicular tissue, with subsequent pregnancy rates of 92.9 versus 71.7%, respectively, and can reduce the amount of additional laboratory work required prior to cryopreservation.[35]

Testicular Sperm Extraction

Sperm retrieval can also be performed directly from the testicle. Open extraction, historically referred to as an open testicular biopsy, can be both beneficial for obtaining a pathological diagnosis as well as for obtaining sperm for reproductive purposes. Testicular sperm extraction (TESE) is performed by exposing the testicle through a horizontal or vertical scrotal skin incision, dissecting out one or both testicles, entering the tunica vaginalis, and making an incision through the tunica albuginea with a scalpel. Meticulous dissection and careful hemostasis using bipolar electrocautery should be implemented to keep a bloodless operating field to minimize testicular fluid contamination. Seminiferous tubules are exposed through the incision and removed using sharp dissection. Tubular contents are then examined under a microscope. If no sperm are seen, the tunica albuginea incision is extended to reveal more tubules and the process is repeated until sufficient sperms are obtained.[36] This process can be greatly enhanced by utilizing a surgical microscope. A microscopic testicular sperm extraction (micro-TESE or m-TESE) allows the surgeon to visualize dilated yellow-hued seminiferous tubules, which are thought to have higher rates of sperm retrieval.[37] In addition, retrieval rates may be higher with testicular volume greater than 12.5 ml.[38]

Though the technique of testicular sperm extraction has changed little over time aside from advantages afforded by the operating microscope, urologists continue to search for ways to predict successful sperm retrieval and to optimize outcomes. One tool of recent interest has been ultrasound. Nariyoshi et al.[39] recently demonstrated that preoperative gray-scale ultrasound of the testis was able to determine tubular diameter, with tubular diameter greater than 250 μmol/l correlating closely with likelihood of sperm retrieval on micro-TESE, with a sensitivity of 77% and specificity of 81%. Additionally, contrast-enhanced ultrasound may be used to determine testicular tissue most likely to yield sperm on a micro-TESE, with shorter time to initial and peak enhancement, and higher peak intensity being positive predictors of sperm recovery.[40] Utilizing these models may facilitate preprocedural counseling and patient selection to optimize sperm retrieval rates.

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