Torsion of the testis

 Predisposing causes

Torsion of the testis (syn. torsion of the spermatic cord) is uncommon because the normal fully descended testis is well anchored and cannot rotate. For torsion to occur one of several abnormalities must be present.

  Inversion of the testis is the most common predisposing cause. The testis is rotated so that it lies transversely or upside down.

  High investment of the tunica vaginalis causes the testis to hang within the tunica like a clapper in a bell (Fig. 68.4). Very occasionally, torsion occurs outside the tunica vaginalis.

  Separation of the epididymis from the body of the testis permits torsion of the testis without involving the cord. The twisting is confined to the pedicle which connects the testis with the epididymis (Fig. 68.5).

Normally, when there is a violent contraction of the abdom­inal muscles, the cremaster contracts as well. The spiral attach­ment of the cremaster favours rotation around the vertical axis when this is made possible by one of the abnormalities described above. Straining at stool, lifting a heavy weight and coitus are all possible precipitating factors. Alternatively, torsion may develop spontaneously during sleep.

Clinical features

Testicular torsion is most common between 10 and 25 years of age and a few cases occur in infancy. Symptoms vary with the degree of torsion. Most commonly there is sudden agonising pain in the groin and the lower abdomen. The patient vomits.

Torsion of a fully descended testis is usually easy to recognise by the high lie of the testis and thickening of the tender twisted cord which can be palpated above it. In mumps orchi­tis the cord is not particularly thickened. The onset of redness of the skin after 6 hours or so and the onset of a mild pyrexia may cause confusion with epididymo-orchitis in the older patient but there will usually be an associated urethritis. Elevation of the testis reduces the pain of epididymo-orchitis and makes it worse in torsion. Very occasionally, the condition can be convincingly mimicked by a small tense strangulated inguinal hernia compressing the cord and causing compres­sion of the pampiniform plexus. If there is any doubt about the diagnosis, the scrotum should be explored without delay.

It is almost impossible to distinguish torsion of an imperfectly descended testis until the parts are exposed at opera­tion. An empty oedematous hemiscrotum on the side suggests that a tender lump at the external inguinal ring is a torted testis.

Treatment

In the first hour or so it may be possible to untwist the testis by gentle manipulation. If manipulation is successful pain subsides and the testis is out of danger. However, arrange­ments should be made for early operative fixation to avoid recurrent torsion.

Exploration for testicular torsion can be performed through a scrotal incision. If the testis is clearly viable when the cord is untwisted, it should be prevented from twisting again by fixation by nonabsorbable sutures between the tunica vaginalis and the tunica albuginea. The opposite testis should also be fixed because the anatomical variation respon­sible for the torsion is likely to be bilateral. A totally infarcted testis should be removed the patient can be counselled later about a prosthetic replacement if this is appropriate. If it is clear that there has been an established torsion for several days it will not be possible to recover the testis and little is gained by exploration. The affected testis will become woody-hard and atrophy to a fibrous nodule. The other testis should be fixed at an early date.

Torsion of a testicular appendage is sometimes mistaken for acute epididymo-orchitis and cannot be distinguished with certainty from testicular torsion. The most common structure to twist is the appendix of the testis (the pedunculated hydatid of Morgagni) but other vestigial structures related to the testis and epididymis may also rotate. Immediate operation with ligation and amputation of the twisted appendage cures the condition. Idiopathic scrotal oedema is a curious condition which occurs between the age of 4 and 12 years and has to be differentiated from torsion. The scrotum is very swollen but there is very little pain or tenderness. The swelling may extend into the perineum, groin and penis. It is thought to be an allergic phenomenon occasionally there is eosinophilia. The swelling subsides after a day or so but may recur (Fig. 68.6).