MALE INFERTILITY: ASPECTS OF SURGICAL TREATMENT
G.A. de Boccard
Obstructive fertility problems are often treated by surgery, the appearance of microsurgery and laparoscopy giving new hope to many infertile men. We will discuss the different surgical techniques to by-pass an obstruction, or repair a varicocele.
The causes of male infertility are multiple, and only a few among them may be cured. The appearance of microsurgery opened a new era, giving hope to patients otherwise classified as definitely sterile.
In the following paragraphs the author will review only the surgically curable causes of infertility. Hormonal and infectious diseases are discussed in another chapter.
Only a few areas of the seminal tract are accessible to surgical procedures: those parts which lie intra-scrotally, subcutaneously or those which can be manipulated endoscopically at the level of the prostatic portion of the urethra.
Congenital or acquired obstruction
Parts of the seminal tract, especially the vas deferens, may be absent or obstructed, usually partially, sometimes in totality. The cause may be congenital, post-infectious or iatrogenic. If only a segment is missing or obstructed, it is possible to by-pass it. In the case of agenesis or obstruction of the rete testis and the first part of the head of the epididymis, there is unfortunately no available treatment and donor insemination or adoption must be considered.
If obstruction is distally located at the level of the body or the tail of the epididymis and in the presence of a normal vas, the therapy of first choice is vasoepididymostomy.
After incision of the scrotum, the testicle and the epididymis are exposed. The vas is dissected and its patency is verified by saline injection. The epididymis is opened at the level of its most distal but still normal portion. A tubule is then chosen and opened and its content microscopically checked for spermatozoa. If no spermatozoa are found at this level, a more proximal tubule is opened until spermatozoa are found or the ductuli efferentes are reached. If no sperm is found at this stage a testicular biopsy is usually performed. When the appropriate tubule is exposed, we prefer to perform an end to side anastomosis with the help of a microspike approximator. We first place four 9-0 Vicryl through the individual epididymal tubule and the vas; then the seromuscular layer of the vas is secured to the tunica of the epididymis by six 8-0 silk sutures.
This procedure has a patency rate of approximately 64% but a much lower pregnancy rate of about 30%. A new technique described by Stefanovic et al. (8) and Shekarriz and Pomer (6), called the loop intussusception or invagination technique gives a much higher patency rate of over 80% in animals, but further human cases are still necessary.
Epididymal sperm aspiration
Until recent years, there was no available treatment in cases of simultaneous absence of the vas. The first description by Temple-Smith et al. (9) of sperm micro-aspiration from the epididymis and in vitro fertilization resulting in a pregnancy, followed by Silber et al. (7), who repeated the procedure with success, opened a new field. Silber had an even better pregnancy rate in cases of agenesis than in those with acquired obstruction.
For the urologist, the technique is quite simple. The preparation of the epididymis is made as described above, but instead of anastomosing the vas, the sperm coming out of the tubule is aspirated in a 2 ml insulin syringe prefilled with Percoll. It is generally possible to collect 10 to 20 million spermatozoa within 30 minutes. The sperm cells are then forwarded to the in vitro fertilization team who have already collected the oocytes from the partner and will manage the follow-up. The epididymal duct and the tunica of the epididymis, as well as the outer layers of the scrotum, should be closed as precisely as possible with 9-0 resorbable sutures, to be able to repeat the procedure easily if required.
The most frequent cause of obstruction of the vas deferens is vasectomy. Among 100 men undergoing vasectomy, 1 or 2 will ask for a reversal. Short segmental agenesis or post-infection localized obstructions are more uncommon. The influence of the delay after vasectomy on the fertility rate following anastomosis is controversial because the fertility rate of normal men decreases naturally with time in any case. Accordingly, it is not possible to assess the fertility outcome without a control group.
Surgically, vasovasostomy can be performed anywhere along the scrotal and inguinal part of the vas. Sometimes it is certainly possible to gain an intraperitoneal access to the vas by a laparoscopic approach. Generally, as a consequence of vasectomy, it is done in the mid or upper part of the scrotum.
We prefer to perform the two-layers technique with the help of a microscope (stereoscopic f: 300 mm lens). A four cm incision is made over the palpable vas, its middle point being on the site of the former vasectomy. The vas and the testicle are then delivered from the scrotum. The vas is dissected and the scarred area is isolated and resected. The distal end is flushed with saline to check its permeability and to dilate the lumen, the proximal end is checked for sperm by an extemporaneous microscopic examination. The microspike approximator is installed. Then six to eight 9-0 resorbable monofilament sutures are placed to approximate the mucosa, followed by the same number of 8-0 resorbable sutures placed on the sero-muscular layer. In order to have a better view of the sutures we recommend placing a plastic opaque drape under the vas during the microscopic step of the operation.
If a microscope is not available, we suggest using the modified two-layers technique which allows very good results and is much easier to perform: Four 8-0 polypropylene sutures are placed at 6, 9, 3 and 12 o’clock through the serosa and the mucosa in order to approximate the two portions of the vas. Then four 8-0 sutures are placed on the serosa between the first four to ensure tightness of the vas. In some cases, the surgeon resects a large segment of the vas, making anastomosis impossible. In those cases it is sometime possible to puncture the vas and collect the sperm for in vitro fertilization (see above).
Our own results show a 100% patency rate, being always over 90% in the different series. The pregnancy rate is between 50 and 60%. As stated before, the fertility rate decreases as the time elapsed between vasectomy and reversal increases, but still the patency rate would be 70% even after more than 15 years of obstruction. It should be noted that the mean time between vasectomy reversal and conception is more than twelve months, and, more important, that the fertility rate of the reversal group is the same as in the normal population (1).
Varicocele is due to the absence of valves in one of the longest vein of the body, the left gonadal vein that drains in the left renal vein. It occurs in about 15% of the normal male population and is found in 40% of those consulting for fertility problems. It is more often bilateral than earlier believed. The presence of a varicocele is determined by physical examination, Doppler sonography confirms the persistence of a retrograde flow during the Valsalva maneuver.
There are two major indications for the treatment of varicocele: scrotal pain and infertility. A painful varicocele is generally large in size and easily diagnosed. The importance of subclinical varicoceles is now established and this pathology should be considered even in the presence of a small retrograde flow (3).
Surgical and non surgical techniques for the treatment of varicocele are available:
Overall results in collated studies of varicocele surgery and embolization show 50% to 90% improvement in semen quality; 30% to 50% of affected couples may achieve pregnancies after 6 to 9 months (5).
Ejaculatory duct resection
At the prostatic level, after the junction with the seminal vesicle the vas ends in the ejaculatory duct. It terminates at the verumontanum. Even a small lesion in that region can cause an obstruction, often bilateral. Generally its etiology is inflammatory, but in some cases a müllerian duct cyst, or a wolffian malformation can be found. This condition is suspected in cases of low semen volume (less than 1.0 ml) and absence of fructose. Perineal pain and hematospermia may be associated. The rest of the vas deferens is usually normal. Ejaculatory duct obstruction is best diagnosed with vasography.
Treatment is performed endoscopically with a resectoscope incision along the verumontanum. Deep resection is sometimes needed and one must be very careful to avoid rectal perforation or sphincter lesion (4).
Edited by Aldo Campana,