Transrectal Ultrasound

Transrectal ultrasound is employed to detect abnormalities of the prostate, seminal vesicles, and ejaculatory ducts. Azoospermic men with low semen volume (<1mL) and at least one palpable vas deferens should be evaluated for ejaculatory duct obstruction with transrectal ultrasound.

Ejaculatory duct obstruction is a rare cause of infertility, accounting for less than 1% of cases. Causes include congenital atresia or stenosis; utricular, müllerian, or Wolffian duct cysts; trauma; and infection. A seminal vesicle diameter of greater than 1.5cm is suggestive of ejaculatory duct obstruction, although there is no definite threshold for making the diagnosis.^7–10

A partial form of ejaculatory duct obstruction may to be present in men with low semen volume and severe oligoasthenospermia. According to some investigators, this condition can be detected by transrectal ultrasound. However, no precise criteria for diagnosing partial ejaculatory duct obstruction is available, and currently this condition is considered investigational.⁷

Testis Biopsy

The indications for a diagnostic testis biopsy are azoospermia with at least one palpable vas deferens.^10–12 It must first be verified that the patient is indeed azoospermic by centrifuging the sample, resuspending the pellet, and repeating the microscopic examination.¹³ The primary purpose of a testis biopsy is to differentiate obstructive from nonobstructive azoospermia. Pathologic analysis should be performed to analyze the pattern of sperm production and to rule out intratubular germ cell neoplasia, which may occur in 0.4% to 1.1% of infertile men.¹⁰ Fixatives such as Bouin’s or zinc formalin allow for maintenance of the testicular architecture for pathologic examination.

A diagnostic classification system devised by Levin is useful in describing the pattern of sperm production.¹⁴ In the setting of azoospermia, more than 20 mature spermatids per tubule on histologic examination would be consistent with a sperm concentration of 10 million/mL, suggesting obstruction.¹⁵

The technique of diagnostic testis biopsy is straightforward. It can be performed through a small scrotal incision with local, regional, or general anesthesia on an outpatient basis. Delivery of the testis is usually not required for a standard biopsy. A biopsy can also be performed percutaneously with a biopsy gun or by fine-needle aspiration, although fewer tubules are obtained this way.^16,17 To avoid injury to significant branches of the testicular artery, the biopsies should be taken from the medial or lateral aspect of the upper pole.¹⁸

If the testes are symmetric, a unilateral biopsy is sufficient to document obstruction. Bilateral biopsies are more important when attempting to maximize the chances for sperm retrieval.¹⁹

Many clinicians believe that isolated diagnostic biopsy is rarely indicated. In cases of suspected obstruction (characterized by normal size testes, normal follicle-stimulating hormone [FSH] level, and indurated or distended epididymis), bilateral biopsies can be analyzed intraoperatively for the presence of sufficient numbers of sperm. Then vasography and microsurgical reconstruction can be performed at the same time. In cases where nonobstructive (small testes, elevated FSH, flat epididymis) azoospermia is suspected, sperm retrieval with cryopreservation can be planned and carried out at the same time.

Vasography

The purpose of a vasogram is to assess the patency of the vas deferens. The indications for vasography are azoospermia, a normal FSH, a testis biopsy with normal spermatogenesis, and at least one palpable vas deferens.^10,12

Virtually all vasal obstructions are iatrogenic. Vasal obstruction can be encountered after inguinal hernia repair or orchidopexy, retroperitoneal surgery such as renal transplantation and, of course, vasectomy. Vasography is not routinely necessary at the time of vasectomy reversal, however. Azoospermic men with normal semen volume, normal spermatogenesis on a testis biopsy, palpable vasa, and no history of inguinal, scrotal, or retroperitoneal surgery will most likely have epididymal obstruction.

Vasography can be performed with either a hemivasotomy or a puncture technique and should be performed only at the time of a planned reconstruction. The puncture technique is technically more difficult to perform. The advantage of the puncture technique is that it does not require separate closure of the vas deferens.²⁰

In most cases where vasoepididymostomy is performed, however, the surgeon can use the vas deferens at the site of transection for the vas-to-epididymis anastomosis; a separate vasal closure is not required. One should try to preserve as much vasal length as possible. Therefore, the ideal site for the vasogram performed at the time of vasoepididymostomy is at the junction of the straight and convoluted vas.

For repair of inguinal vasal obstruction or transurethral resection of the ejaculatory ducts, the vasogram could be performed in the scrotal straight vas at a site proximal to the suspected obstruction. For repair of inguinal vasal obstruction or transurethral resection of the ejaculatory ducts, the puncture technique would therefore have a distinct advantage by eliminating the need for a separate vasal closure.

Injection should be performed in the antegrade direction only. Iodinated contrast medium is injected and a plain x-ray is obtained to delineate the vasal anatomy. Alternatively, methylene blue or indigo carmine can be injected and the bladder catheterized. If the urine is blue, then patency of the vas is confirmed. Finally, some surgeons simply inject saline solution in an antegrade fashion and assess the ease of injection.

If there is no difficulty with the injection, one can assume that the vas distal to the injection site is patent.¹⁰ A normal x-ray vasogram should demonstrate a barely perceptible but patent vasal lumen coursing from the scrotum through the inguinal canal to the pelvis, with filling of the ejaculatory ducts and bladder.

Inguinal Vasal Obstruction

Obstruction of the vas deferens can occur after inguinal, scrotal, and retroperitoneal surgery.²¹ Reconstruction of the retroperitoneal vas is usually not possible secondary to retraction of the distal end, and reconstruction of the inguinal vas is challenging and in some cases not possible.

Inguinal vasal obstruction is the most likely diagnosis in men who present with normal-volume azoospermia and a history of bilateral inguinal surgery or unilateral surgery and atrophy or absence of the contralateral testis or ductal system. Before attempting surgical correction, a testis biopsy is performed to confirm normal spermatogenesis, followed by vasography to document the obstruction.

Inguinal vasal reconstruction begins with mobilization of the two ends of the vas deferens followed by a microsurgical anastomosis with either a modified one-layer or formal two-layer technique. Difficulties encountered with inguinal vasal reconstruction stem from the inability to isolate and mobilize the distal (abdominal) end and the dense scarring that occurs, particularly with mesh, after inguinal hernia repairs.^22,23

Secondary epididymal obstruction can occur. If sperm are not seen in the vas fluid and the patient remains azoospermic postoperatively, then a secondary epididymal obstruction should be suspected. In this scenario, the vasal obstruction should be corrected first, followed by correction of the epididymal obstruction 6 months later.

In cases where there is inguinal vasal obstruction on one side and an atrophic testis with a normal ductal system on the contralateral side, strong consideration should be given to a trans-septal or “crossover” vasovasostomy because this is technically less complicated than performing an inguinal dissection and anastomosis. Sperm retrieval and in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) should be considered as an alternative.²⁴

Vasectomy Reversal

Vasectomy is one of the most popular forms of contraception and as many as 4% to 10% of men who undergo a vasectomy request a reversal.²⁴ This procedure is performed as an outpatient with local, regional, or general anesthesia. Secondary epididymal obstruction can occur; in these cases vasoepididymostomy, rather than vasovasostomy, is required.²⁵ Vasoepididymostomy is significantly technically more demanding than vasovasostomy. Vasovasostomy and vasoepididymostomy are usually performed through bilateral high scrotal incisions.

Vasovasostomy

The first step in performing a vasovasostomy is to mobilize the vas deferens proximal and distal to the vasectomy site while maintaining the vasal blood supply. A sufficient length of both the testicular and abdominal ends must be obtained to allow for a tension-free anastomosis. The vas is then transected proximal to the vasectomy site and microscopic examination of the fluid is performed.

Microscopic examination of the fluid is important both to decide whether vasoepididymostomy is necessary and to understand the cause of failure if the patient remains azoospermic postoperatively. If the vasal fluid lacks sperm, then vasoepididymostomy should be considered particularly if the fluid is thick and pasty.

The vasal anastomoses can be performed with either a modified one-layer technique with 9-0 nylon or a formal two-layer technique with 10-0 and 9-0 nylon (Figs. 53-1 and 53-2).²⁶ With the modified one-layer technique, four to six full-thickness 9-0 nylon sutures are placed with four to six 8-0 or 9-0 nylon sutures in the muscularis in between the full-thickness sutures. In the formal two-layer technique, the vasal mucosa is reapproximated as a separate layer with interrupted 10-0 nylon and the muscularis with 9-0 nylon.²⁷

Figure 53-1 Vasovasostomy; modified one-layer technique. Four to six full-thickness nylon sutures are placed.

Figure 53-2 Vasovasostomy; two-layer technique. The vasal mucosa is reapproximated as a separate layer.

Vasoepididymostomy

The initial approach for vasoepididymostomy is similar to that for vasovasostomy. If thick, pasty vasal fluid without sperm is noted, vasoepididymostomy should be considered. The incisions are extended and the tunica vaginalis is opened to deliver the testis and spermatic cord. Typically, the site of epididymal obstruction can be identified by its distension and bluish brown discoloration. The vas deferens is mobilized distally to allow for sufficient length to reach the epididymis. This can require dissection up to the external ring with extension of the incision superiorly.

The epididymis is then explored in a systematic fashion in a proximal direction. Individual single epididymal tubules are opened until sperm are seen on microscopic examination of the fluid. Once sperm are seen, the surgeon knows that he or she is proximal to the obstruction.

The vas deferens is then routed behind the cord to lie next to the epididymis and aligned with the epididymal tubule by placing 9-0 nylon sutures from the tunica of the epididymis to the muscularis of the vas deferens. In the traditional end-to-side technique five to eight 10-0 nylon sutures are placed into the open epididymal tubule and then to the mucosa of the vas deferens. The outer layer of the anastomosis is then completed by anastomosing the remainder of the epididymal tunic to the muscularis of the vas deferens with 9-0 nylon (Fig. 53-3).²⁸ The scrotum is then closed in layers with absorbable suture.²⁹

Figure 53-3 Vasoepididymostomy. A single epididymal tubule has been opened and sutured to the mucosa of the vas.

Newer techniques for vasoepididymostomy involve intusussception of the epididymal tubule into the lumen of the vas deferens. A triangulation technique with three double-arm 10-0 sutures was described by Berger and a two-suture technique was described by Marmar. With these techniques, the double-arm sutures are placed in the distended epididymal tubule before it is opened. The tubule is opened between the previously placed double-arm sutures and these are then placed in the corresponding position of the mucosa of the vas deferens. The outer layer of the anastomosis is completed with 9-0 nylon sutures from the tunica of the epididymis to the muscularis of the vas deferens.

The main advantages of these newer intusussception techniques are that the 10-0 sutures are easier to place in a distended tubule and the intusussception of the epididymis into the lumen of the vas deferens may reduce leakage. Patency may occur sooner than with traditional vasoepididymostomy, but pregnancy data for these newer techniques are generally lacking.^30,31

Success Rates

Patency rates for vasovasostomy and vasoepididymostomy range from 75% to 93% and 67% to 85%, respectively. Patency rates depend on the obstructive interval (time since the vasectomy), the quality of the vasal fluid noted at surgery, whether epididymal obstruction is present, and surgical technique. Although vasovasostomy can be performed without an operating microscope, microsurgical technique generally yields superior results.³⁵ Accurate performance of vasoepididymostomy without microsurgery would be essentially impossible.

Pregnancy rates for vasovasostomy and vasoepididymostomy range from 46% to 82% and 27% to 49%, respectively^{27,33,36–48} (Tables 53-1 and 53-2). Pregnancy rates depend on the above variables as well as female factors and other factors such as antisperm antibodies.

Table 53-1 Results of Microsurgical Vasovasostomy

Table 53-2 Results of Microsurgical Vasoepididymostomy

In the study by the Vasovasostomy Study Group, a group of experienced microsurgeons examined the effect of obstructive interval and vasal fluid quality on patency and pregnancy rates. They clearly demonstrated that patency and pregnancy rates were inversely related to the obstructive interval. Patency and pregnancy rates were 97% and 76%, respectively, for obstructive intervals of 3 years or less, 88% and 53% for 3 to 8 years, 76% and 44% for 9 to 14 years, and 71% and 31% for 15 years or greater.

Vasal fluid quality, both the gross and microscopic appearance, was also an important prognostic factor. The patency and pregnancy rates for grossly clear fluid were 91% and 49%, repectively, for opalescent (cloudy, but thin and watery) fluid 93% and 59%, for thick/creamy fluid 70% and 45%, and for no fluid 88% and 54%. The patency and pregnancy rates were 94% and 63%, repectively, if motile sperm were present, 90% and 54% for nonmotile sperm, 96% and 50% for mostly sperm heads but some with tails, 75% and 40% for sperm heads only, and 60% and 31% if sperm were absent. Thus, the absence of sperm in the vasal fluid significantly lowers the success rate, but patency and pregnancy can still occur.³³

If sperm are absent from the vasal fluid, epididymal obstruction may be present. Some investigators therefore recommend vasoepididymostomy if sperm are absent from the vas fluid, regardless of other factors. In a series of 44 patients with intravasal azoospermia, all patients remained azoospermic postoperatively. It was concluded that vasoepididymostomy should be performed if sperm are absent from the vas fluid.⁴⁰ In the Vasovasostomy Study Group, the patency and pregnancy rates if sperm were absent in the vas fluid were 60% and 31%, respectively. Because epididymal obstruction is more likely to occur as the obstructive interval increases and thicker vasal fluid is more suggestive of epididymal obstruction, it is possible to apply vasoepididymostomy selectively and still obtain acceptable results. The Vasovasostomy Study Group recommended that vasoepididymostomy be considered if there was thick pasty fluid without sperm and the obstructive interval was 9 years or more.³³ In another study, Kolettis and colleagues found that if vasovasostomy were applied in instances of intravasal azoospermia where the obstructive interval was 11 years or less, the patency and pregnancy rates were 80% and 38%, respectively, similar to those for vasoepididymostomy.⁴⁹

Epididymal Obstruction

Epididymal obstruction can be congenital, postinflammatory, posttraumatic, or related to inspissated secretions. Some men with epididymal obstruction will have a history of trauma or epididymitis. In most other cases there will be no other clear details in the history to identify the cause of the azoospermia.

Epididymal obstruction can occur secondary to inspissated secretions in men with Young’s syndrome. This syndrome is characterized by a combination of obstructive azoospermia and chronic sinopulmonary infections in men without cystic fibrosis.¹⁰

The typical clinical presentation for a man with bilateral epididymal obstruction is the finding of normal-volume azoospermia, with a palpably normal vas deferens, a normal FSH level, and an indurated or distended epididymis.

If epididymal obstruction is suspected based on these clinical clues, the patient should be scheduled for testis biopsy, vasography, and possible bilateral vasoepididymostomy, all of which can be done at the same time. In these cases, the testis biopsy will document normal spermatogenesis. An intraoperative wet preparation of the biopsy will demonstrate the presence of significant numbers of sperm.⁵⁰ Permanent pathology is required to document the pattern of sperm production. After vasography, a vasoepididymostomy can be performed. If the patient desires, simultaneous sperm retrieval can be carried out at the same time.