An undescended testicle occurs when one or both testes cannot be found in the scrotum. The incidence is 3-4 % of newborn males and is more common in preterm infants. Most undescended testes occur on just one side (80%). In a smaller percentage of cases, they occur on both sides (20%).
Many male infants and children who are referred for evaluation of an undescended testicle turn out to have a retractile testicle. This is a testicle that typically resides in the low inguinal canal or high scrotum, but which may move into the scrotum while the child is asleep, at rest, or in a warm bath. Retractile testes are usually bilateral (occurring on both sides), and both sides of the scrotum are well developed. If a high testicle can be manipulated into the scrotum, completely released, and re-grasped in the scrotum without further manipulation, one is dealing with a retractile testicle. In this case, as the child matures and the testicle enlarges, gravity will eventually pull the testicle into the scrotum.
If, on the other hand, the child is six months old and one must repeatedly manipulate the testicle to bring it into the scrotum, and it does not remain there when released by the examiner, it is undescended and will require surgical correction. The five principal reasons for surgical correction of an undescended testicle are:
Male fertility (the ability to father children) in the setting of an uncorrected one-sided undescended testicle ranges between 40-65%. In comparison, fertility in a one-sided undescended testicle that is repaired before six years of age is about 80-90%. (The lower fertility rate associated with all undescended testicles is attributed to the higher-temperature environment of the non-scrotal testis.)
A testicle that lies in the inguinal canal (groin) is at risk for crush injury, as it is relatively immobile and sits on top of stiff ligaments and bone. About 90% of inguinal testicles have an associated hernia-like sac, which predisposes to hernia formation. The hernia will be repaired at the time of orchidopexy.
Orchidopexy is a surgical procedure that moves an undescended testicle into the scrotum. The operation is performed to reduce the risk of crush injury, correct the associated hernia, and/or alleviate the psychological concerns of having only one testicle visible in the scrotum.
An orchidopexy does not, however, protect against the 8-10 fold increased incidence of testicular cancer in patients with a history of undescended testicle. Moreover, the timing of orchidopexy appears to have only a minimal effect on the rate of testicular malignancy in these patients. Orchidopexy does, however, offer a crucial benefit: by moving the testicle into the scrotum, it makes it much easier to monitor for signs of cancer in the future (i.e., doctors can feel for irregularities in the testicle by hand). Easier monitoring means a better chance of early detection in the event a tumor develops.
Orchidopexy for a palpable undescended testicle is performed through a groin incision. The abnormal attachments of the testicle in the inguinal canal are divided, and the hernia sac (if present) is carefully freed from the testicular blood vessels and vas deferens.
The ability to bring the testicle into the scrotum is limited by the length of the testicular artery. When the artery is particularly short, the testicle, its blood supply, and the vas deferens may be brought beneath the epigastric vessels to run directly into the scrotum.
A testicle that cannot be found in the groin or the scrotum may be in the abdominal cavity. These testicles (referred to as “nonpalpable” because they cannot be felt by hand, and “intraabdominal” because they are located in the abdomen) can sometimes be located via an ultrasound or CT scan of the abdomen. Sometimes, however, testicular tissue is present and cannot be located by either of these tests.
The only way to establish with certainty that a testicle is completely absent is by direct visualization of blind-ending testicular vessels and a blind-ending vas deferens. Therefore, the first step in managing a unilateral nonpalpable testis (a testicle that cannot be found by physical examination) is laparoscopy (a procedure in which a camera in a lighted tube is inserted into the body through a small incision in the abdomen).
This information is provided by the Department of Surgery at the University of Colorado School of Medicine. It is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition.