Vasectomy reversal
Sperm are being made continually in a mass of small tubes coiled up in the testes (seminiferous tubules). The tubes eventually join to form 6-8 tubes, which emerge just behind the upper part of the testis (rete testis). These tubes run down the back of the testes gradually joining to each other (epididymis). At the lower part of the testes the epididymes turn upwards and for a short length run towards the groin as a thin walled twisted tube (convoluted vas deferens). The convoluted tube becomes a straight tube with a thick wall (vas deferens) about 1 cm above the lower part of the testis. From there it runs up through the scrotum and groin and then enters the pelvis. In the pelvis the vas deferens goes to the back of the prostate gland and empties into the water passage (urethra). During ejaculation sperm are pumped out from the vasa into the urethra accompanied by fluid from small nearby storage glands (seminal vesicles)
Vasectomy
During the vasectomy operation the vas on each side is divided to prevent sperm traveling to the urethra. Usually a piece of the vas is removed and the ends tied off. The length of vas removed varies from a little as 1 cm to several centimeters. Usually only a short length is removed.
Patients should consider the operation to be an irreversible contraceptive measure although early and late failure is possible. In order to try and reduce the failure rate some surgeons take away a longer piece of vas and/or pass a hot needle into the vas to obliterate its cavity (lumen). These procedures are important when considering the feasibility and success rate of vasectomy reversal procedures.
It is a curious fact that if sperm escape from their normal site in the body they are recognized as foreign material and as a result the body may produce proteins (antibodies) in an attempt to get rid of them. This is one of the normal mechanisms by which the body protects itself against infection. Sperm antibodies coat the sperm and may render them incapable of fertilizing an egg. If present, sperm antibody production may continue even after successful vasectomy reversal. This is another factor, which may affect the result of vasectomy reversal.
Vasectomy reversal
THE OPERATION
Vasectomy reversal is usually performed under general anaesthetic and may take an hour or more to perform. The areas where the vasectomy was performed are exposed through short incisions on either side of, or a single incision in the middle of the scrotum. Scar tissue is removed to expose both ends of the vas at points where the lumen is open. The ends are then joined together with a series of fine sutures often using magnification. The skin incision is closed with 4 or 5 stitches, which dissolve away over the following 2 to 3 weeks.
The operation may be performed as a day case but sometimes the patient remains in hospital over night.
Patients are given instructions about how to manage their incision whilst healing occurs and are told to avoid exercise for at least a week after the operation. During this time some form of firm scrotal support is helpful to prevent excessive swelling or discomfort.
Complications
SHORT TERM. Some swelling and bruising of the scrotum is to be expected for a week or so after the operation. In addition it is not unusual for there to be some minor infection of the superficial part of the wound although this rarely requires antibiotic treatment. Discomfort and pain are not usually severe and are easily managed with mild pain killers
LONG TERM. Although unusual, some patients may experience chronic discomfort in one or both testes.
Results
After the operation it is usual for the patient to be asked to provide a sample of semen to be examined for the presence of sperm. The optimum time for this examination is 12 weeks after the operation in order to give time for the testes to recover sperm production.
In about 10% of patients sperm does not appear in the semen. In these patients the operation has failed.
In the rest; sperm may be found but in varying numbers. A normally fertile male has in excess of 20 million sperm in each milliliter of semen and at least 25% of these sperm should be seen to be moving normally.
Many men will have either a low sperm count or poor sperm motility after the operation and as result will have a reduced chance of fathering a child.
In addition, if present, sperm antibodies will reduce the chance of fathering a child even in the presence of a normal sperm count.
Overall; even in the most optimistic of circumstances only about 40% of men will father children after a vasectomy reversal.
Factors which reduce the chance of success
TIME SINCE THE VASECTOMY.
If the period from vasectomy to reversal is less than 10 years the result of the operation is not significantly affected. When the period is more than 10 years the success rate is lower but successful outcomes have been reported in men undergoing vasectomy reversal when the time from the vasectomy has been considerably longer.
TECHNICAL DIFFICULTIES
If the vasectomy has been performed close to the testis only the convoluted vas may remain below to join to the normal vas above. As these tubes have walls of different thickness and lumens of different diameters it is technically more challenging to join them together satisfactorily. In addition the curved nature of the lower end increases the difficulty. In cases where a long piece of vas has been removed in may prove to be difficult to bring the ends together in a satisfactory manner. If the lumen of the vas has been obliterated with a hot wire it may be impossible to perform a reversal procedure. If technical difficulties are present they are likely to adversely affect the success rate of the procedure.
SPERM HARVESTING AND ICSI
During the reversal operation it may be possible to obtain some living sperm from the cut end of the vas; the epididymis (Micro Epididymal Sperm Aspiration – MESA) or the testis itself (TEsticular Sperm Aspiration – TESA, or testicular biopsy). This is not always possible but when it is, it offers the patient an alternative way of fathering a child if the reversal procedure is a failure. The sperm can be successfully frozen and stored at -70C. When they are thawed out many will retain the ability to fertilise an egg even many years later. The number of sperm obtained is insufficient for use in artificial insemination procedures. Instead the procedure of Intracytoplamic Sperm Injection (ICSI) must be employed. During ICSI an egg obtained from the patient’s partner is injected with a single sperm and incubated in culture fluid. If the egg begins to divide it can be placed in the womb and in about 20% of times at each attempt a successful pregnancy may result.
ICSI does of course involving the patient’s partner in an invasive procedure in order to harvest eggs and there is an additional cost element at each stage (sperm harvesting; sperm storage and the ICSI procedure itself).
