Spermatic Cord Block

Any patient undergoing a sperm retrieval procedure under local anesthesia will appreciate a well-done spermatic cord block. The nerves that innervate the contents of the scrotum travel along the spermatic cord; however, the overlying scrotal skin is innervated separately and requires a separate block. Spermatic cord blocks are best performed by firmly capturing the spermatic cord against the scrotal skin on the superiormost aspect of the scrotum with the nondominant hand. While isolating the cord, be sure to ascertain that the vas deferens (the most posterior portion of the cord) is secured within the surgeon’s fingers. Blocks performed at this higher level will decrease the risk of injury to the epididymis and ensure that all afferent fibers are included in the blocked region. A small-gauge needle (23–25 gauge) that is 2 inches long is sufficient; smaller gauge needles preclude the need for blocking the skin at the sight of puncture. After passing the needle through the skin and directly through the spermatic cord, aspirate to ensure the needle has not been introduced into the rich vasculature of the cord. Injection can initially be done in the perivasal region to provide complete block of sensation to the vas and epididymis. The remainder (10 cc of local anesthetic) should be progressively injected during slow withdrawal of the needle through the cord. In the operating room, direct visualization of the cord will allow an even more accurate blockade; however, negative aspiration of blood is still warranted.

The choice of local anesthetic depends on physician preference, but 5 to 10 mL of 1% lidocaine or 0.5% bupivacaine is typically used. Alkalinization with 9 : 1 ratio of 8.4% sodium bicarbonate is suggested for office-based procedures to attenuate the pain that can accompany the injection of acidic solutions. In addition, because the scrotal skin is not anesthetized with cord block, skin wheals of local anesthesia that overly the location of office-based testicular biopsy sites are necessary at the site of biopsy or biopsy gun entry.

Testicular Biopsy

Testicular biopsy in the office can be performed by either fine-needle aspiration (FNA) or percutaneously with a biopsy gun. Both require a site directed skin wheal and spermatic cord block. After ensuring localized anesthesia, the scrotal skin is held taut over the testis, which is held in place with the nondominant hand. FNA requires 18- to 25-gauge needles that can be introduced into the testis. Steady aspiration as the needle is repeatedly passed through the testicular parenchyma will cause disruption of the tubules and allow aspiration of their contents. Percutaneous biopsy requires a small skin nick to accommodate a 14-gauge, 10-cm biopsy gun, preferably with short (1-cm) excursion. Core biopsies yield notably more tissue than FNA, but FNA should be sufficient for postvasectomy sperm retrieval or retrieval of sperm from men with obstructive azoospermia.

Any instruments that are introduced into the testis should be done so anteromedially or anterolaterally so as to decrease the risk of injury to the subtunical vessels. The main testicular blood supply inserts posteriorly, under the epididymis, and bifurcates into multiple branches to travel medially and laterally just deep to the tunica albuginea. These subtunical vessels are end arteries and provide the sole inflow for the corresponding region of testicular parenchyma into which they dive. Disruption of these vessels may cause ischemia and ultimately destroy any spermatogenesis and hormone production that was taking place in that region.

Open biopsies yield still more testicular tissue and may be done under local anesthesia, spinal cord block, or sedation in addition to local. After exposure of a small window of testis through a 1-cm scrotal incision, a 0.5-cm incision can be made into the tunica. Seminiferous tubules will spontaneously extrude with testicular pressure and can be sharply excised ( Fig. 107.1 ) These incisions, unlike with FNA or percutaneous biopsy, warrant closure; a running 5-0 polypropylene can be used to close tunica albuginea, and separate 4-0 absorbable monofilaments can be used for the tunica vaginalis, dartos, and skin. Incisional anesthesia can be obtained with 0.25% bupivacaine with epinephrine, and a cord block is again warranted.

Incisional testis biopsy.

Percutaneous Epididymal Sperm Aspiration

Percutaneous epididymal sperm aspiration (PESA) is an approach used for random extraction of sperm from the epididymis. Unfortunately, it tends to retrieve sperm with limited motility and an increase in sperm DNA damage. The blind introduction of needles into the epididymis may carry some risk of injury to the testicular vessels as well as inducing epididymal obstruction. Importantly, because the testicular artery inserts into the testis underneath the head and body of the epididymis, it is possible to damage the artery with ensuing loss of the entire testis. In addition, the likelihood of causing secondary obstruction because of disruption of the epididymis is significantly increased. Coupling these marked risks with a sperm retrieval failure rate of 20% underscores the value of considering alternative techniques for sperm retrieval. When sperm retrieval from the epididymis is warranted, the assistance of the operating microscope is encouraged to identify sites of sperm production with optimal motility and lowest sperm DNA fragmentation.