Epidemiology^[1]

It is fairly common and usually seen in adolescent boys. It usually occurs in children aged between 7 and 12 years. A prenatal form has been identified.The left side is more commonly affected than the right, with 2% of cases being bilateral.^[1] There were 2,405 cases admitted to hospitals in England in the year 2009-2010. The mean age of patients was 17 years.^[2]

Risk factors^[1]

A high insertion of the tunica vaginalis produces a 'bell clapper testis' with a horizontal lie rather high in the scrotum. This lie with the long axis in the horizontal rather than the vertical plain is usually bilateral.

Presentation^[1]

Acute swelling of the scrotum in a boy indicates torsion of the testis until proven otherwise. In approximately two thirds of patients, history and physical examination are sufficient to make an accurate diagnosis.

History

• There is typically sudden, severe pain in one testis.
• There may be lower abdominal pain and, in any boy presenting with abdominal pain, the testes should be checked.
• It often comes on during sport or physical activity.
• There is quite often a history of previous, brief episodes of similar pain. This is presumably torsion that corrected itself. There may be nausea and vomiting.
• Occasionally, the symptoms are milder and less acute.
• Easing pain is not necessarily a good sign of spontaneous resolution. Pain also eases as necrosis sets in.

Examination

• There is usually reddening of the scrotal skin.
• There is a swollen, tender testis retracted upwards.
• Lifting the testis up over the symphysis increases pain, whereas in epididymitis this usually relieves pain.
• In the early stages, the epididymis may be felt in an abnormal anterior rather than typical posterior position but this depends upon the degree of torsion that may be from 180-720°. Later, gross swelling prevents this finding.
• The testes on both sides are characteristically in the 'bell clapper position' with a horizontal long axis.
• If the torsion occurs prenatally, the baby is born with a firm, hard, non-transilluminable scrotal mass. There are no symptoms.The scrotal skin is usually fixed to the underlying necrotic testis.

Differential diagnosis^[1]

• Torsion of testicular or epididymal appendage:
  • This usually occurs in boys aged between 7 and 12 years.
  • Systemic symptoms are rare.
  • There is usually localised tenderness but only in the upper pole of the testis.
  • Occasionally, the 'blue dot sign' is present in light-skinned boys (ie tender nodule with blue discoloration on the upper pole of the testis).
• Epididymitis, orchitis, epididymo-orchitis:
  • These conditions most commonly occur from the reflux of infected urine or from sexually acquired disease caused by gonococcus and Chlamydia spp. Hence, they tend to affect an older age group.
• Hydrocele:
  • Swelling is usually painless.
  • The scrotum will transilluminate.
• Incarcerated hernia:
  • This may be diagnosed by careful examination of the inguinal canal.
• Testicular tumour:
  • Scrotal enlargement occurs more slowly.
  • It is only rarely accompanied by pain. Typically, the normal slightly delicate sensation of the testis is absent.
• Mumps:
  • There is swelling of the parotid glands in mumps.
  • Mumps orchitis is rare before puberty.
• Scrotal abscess:
  • This has been mistaken for torsion in a premature infant.^[4]

Investigations^[1]

Urinalysis may be helpful in borderline cases, to exclude urine infection and epididymitis.

The most important investigation is ultrasound integrated with colour Doppler. A very significant finding is the detection of presence/absence of intratesticular blood flow for the early identification of testicular torsion. Further enhancements such as grey-scale imaging have improved the diagnostic power of this modality even further.^[5]

Other useful modalities include dynamic contrast magnetic resonance imaging and near-infrared imaging.^[6]

A survey of urologists in the North-west of England found that 4 of 29 always like to use imaging. Most use it only if the clinical diagnosis is unclear. It is imperative to remember that this is a condition in which time is of the essence and waiting a couple of hours for a slot in the ultrasound department may compromise the viability of the testis.^[7]

Nuclear testicular scan is sometimes employed to differentiate torsion from acute epididymitis.

Management^[8]

• It may be possible to reduce the torsion manually. The testes usually rotate in different directions. The left testis rotates anticlockwise and the right testis clockwise in torsion. Hence, they need to be rotated in the opposite direction. If this relieves the pain it is the correct direction. If it aggravates it, try the other direction.
• If this is done, it should be verified by colour Doppler. If the manoeuvre is successful, orchidopexy must still be performed. This should be done in the immediate future, preferably before the patient leaves hospital.
• Nicotinamide has been found to improve testicular reperfusion.
• If full manual reduction of torsion cannot be performed, or if there is doubt about the diagnosis and reason to suspect torsion, the scrotum must be explored.
• The testis must be unwound at operation and inspected for viability. If it is not viable, it should be removed.
• If the testis is viable then orchidopexy is usually performed to prevent recurrence, although there is no consensus about this as the evidence base is small.^[9]
• Whether the affected testis is removed or conserved, the contralateral one should undergo orchidopexy, as the risk of recurrence on the other side is otherwise high.^[7]
• A baby born with testicular torsion should have the affected testis removed (because it is always nonviable) and orchidopexy of the other side (because bilateral torsion is common).

Complications

Complications of an untreated or delayed torsion include infarction of the testicle with subsequent atrophy, infection and cosmetic deformity.^[10] There is some evidence that retention of an injured testis can cause pathology in the contralateral testis, abnormal semen analysis,^[1] and decreased fertility.^[1]

Prognosis^[1]

• The extent and duration of torsion have a major influence on both the immediate salvage rate and late testicular atrophy.
• Testicular salvage most likely occurs if the duration of torsion is less than 6-8 hours.
• If it exists for 24 hours or more, testicular necrosis is usual.
• One study reported successful harvesting of semen from a subjectively dead testicle, indicating that salvage and cryopreservation of semen should be attempted in all but the most hopeless cases.^[11]
• The absence of one testis has no significant effect on fertility, provided that the other functions normally. If both are affected by torsion, the outlook may be very bleak.
• The absence of a testis may still have a significant psychological effect and so it is usual to implant a prosthesis if orchidectomy is required. This is usually delayed for 6 months to let inflammation subside and it is usually inserted via an inguinal incision.^[12]

In men who have had a unilateral torsion, fertility is often impaired. This may be due to subclinical torsion on both sides. Another possibility is that a pathological condition predisposes to both abnormal spermatogenesis and torsion of the spermatic cord. The 'bell-clapper' testis tends to be high and so temperature may be higher than in glands that hang lower. There may also be an autoimmune component as a result of injury to one testis.^[13]

Prevention

Recurrent, intermittent pain, with a 'bell-clapper' testis, requires orchidopexy.^[14] Delay has a considerable adverse effect on survival of the testis and late presentation is a substantial problem. One study found that the main factor involved in patients who have orchidectomies is length of symptoms and distance from hospital; public education initiatives are likely to prove beneficial.^[15]