Section 1: Aetiology and epidemiology
Testicular torsion is a urological emergency seen predominantly in paediatric patients and young adults.
The annual incidence is 1 in 4,000 in patients aged under 25 years.1
Approximately 400 boys a year lose a testicle because of a delay in presentation or a failure to diagnose and manage the condition correctly.2
The mechanism of torsion relates to the anatomical insertion of the tunica vaginalis onto the spermatic cord. Normally the tunica vaginalis covers the anterolateral surface of the testicle.
A high insertion of the tunica vaginalis results in a mobile testicle within the tunical cavity that is at risk of twisting on its own blood supply.
Clinically this anatomical variation presents as a horizontal lying testicle referred to as a 'bell clapper' deformity.
There are two age groups that have an increased incidence of testicular torsion.
The peak incidence is around puberty and this accounts for 65 per cent of cases.
It has been suggested that the increase in the testicular mass at puberty is a predisposing factor leading to intravaginal torsion.
There is another smaller peak of testicular torsion incidence within the first year of life. In neonates the cord and testicle may twist en masse. This is referred to as an extravaginal torsion.
Isolated cases of testicular torsion have also been reported in older men, although it is very rare in this age group.
Trauma has been proposed as a risk factor for testicular torsion. A study of 670 patients with testicular torsion found a history of trauma in 4 per cent of cases.3
Up to 35 per cent of patients may have a history of acute testicular pain that spontaneously resolved. This is an intermittent torsion due to an underlying bell clapper deformity.
Section 2: Diagnosis
Testicular torsion should be suspected in all patients presenting with acute unilateral scrotal pain. The clinical features are variable and the diagnosis can be difficult to make on clinical grounds. In any case where there is doubt, urgent scrotal exploration is indicated.
The patient's history may include intermittent torsion, trauma, or the onset of acute pain that wakes them up. A history of torsion that required exploration and fixation does not exclude the diagnosis, as torsion can re-occur.
More general symptoms include abdominal pain and vomiting (20-30 per cent). Testicular examination should be included in any assessment of young men with abdominal pain.
In acute cases the body of the testicle is tender and swollen on palpation and may lie higher in the scrotum than on the contralateral side.
Erythema and oedema of the overlying scrotal skin occurs later. The contralateral testicle may also show a bell clapper deformity. The spermatic cord is tender and the cremasteric reflex is absent.
It can be hard to differentiate testicular torsion from epididymitis in patients who present acutely.
In testicular torsion there is no improvement of the pain on elevating the scrotum, whereas the pain improves in cases of epididymitis (Prehn's sign).
Prepubescent boys with a history of progressive but tolerable pain who have no other symptoms are likely to have a torsion of a testicular appendage. This is often associated with pin-point tenderness of the upper pole of the testicle and the presence of a 'blue dot', sign caused by the infarcted cyst being visible through relatively thin scrotal skin.
Torsion of a testicular appendage can lead to ongoing pain, and exploration and removal are recommended to ensure there is no concomitant testicular torsion and to allow a faster recovery.
Investigations are rarely required as they delay surgical exploration. However, imaging has been used in some cases to ascertain testicular blood flow, and a urine dipstick can be carried out in cases of suspected epididymo-orchitis.
In experienced hands, colour Doppler ultrasound scanning has a sensitivity of 88 per cent and specificity of 90 per cent. It can be used to show testicular blood flow and confirm that a testicle is viable, but false positives leading to an incorrect diagnosis can have catastrophic consequences.4
The use of radioisotope scans that show photopenic areas in the testicle is limited by availability and sensitivity.
Ultrasound scans can be useful in patients with a history of longer than 24 hours to confirm a non-viable testicle or in patients where the duration of symptoms is over 24 hours and unlikely to be a torsion.
|Differential diagnosis for acute scrotal pain|
| Torsion of testicular appendage|| Peak incidence 10 years old|
|Epididymo-orchitis|| Rare in children|
|Hernia|| Exclude by examination|
|Idiopathic scrotal oedema|| Boys under seven. Non tender testicle.|
Oedema extends to groin
|Henoch-Schonlein purpura||Associated with skin lesions elsewhere|
|Testicular tumour||Palpable abnormality confirm on ultrasound|
|Hydrocele||Unlikely to cause severe pain|
|Differential in paediatric cases|
Section 3: Management
If a testicular torsion is left untreated for more than eight hours, testicular atrophy can result.
Urgent referral to a urology team for testicular exploration is therefore required in all suspected cases of torsion which has lasted less than 24 hours.
Surgery is performed under a general anaesthetic.
The ipsilateral testicle is delivered through a midline scrotal incision, untwisted and assessed for viability.
Where it is deemed viable it is returned and fixed in the scrotum. The contralateral testicle is also delivered and fixed (see above).
Several methods can be used to fix the testicle. A sutureless fixation is commonly performed by paediatric surgeons.
This involves the creation of a dartos pouch combined with a Jaboulay procedure which everts the tunica vaginalis.
Three-point fixation to prevent retorsion along either axis can be carried out using absorbable PDS (polydioxanone) or vicryl sutures or non-absorbable prolene.
The formation of adhesions between the testicle and the dartos muscle following exploration is sufficient to prevent retorsion.
Where the testicle is known to be non-viable because the torsion has lasted more than 24 hours, a semi-urgent orchidectomy is performed with fixation of the contralateral testicle.
If a non-viable testicle is found at the time of exploration, then a scrotal orchidectomy is performed, again with fixation of the contralateral testicle.
In cases of prenatal extravaginal torsion, the testicular salvage rate is essentially zero.
Elective removal and fixation of the contralateral testicle is performed.
A testicular prosthesis can be offered at a later date in order to reduce the risk of infection.
Section 4: Prognosis
The risk of testicular atrophy depends on the number of twists and the duration of torsion. The degree of arterial occlusion depends on the number of twists in the cord.
A 360 degs twist is likely to produce irreversible ischaemic damage quicker than a partial twist initially due to venous occlusion.
Multiple twists up to 720 degs are more likely to result in arterial occlusion.
If the torsion lasts for longer than eight hours, there is a high risk of long-term atrophy if the testicle is salvaged and retained within the scrotum.
The effect of testicular torsion on long-term fertility is related to the age at which it occurs.
Prepubertal torsion does not affect the contralateral testicular development or result in abnormal semen.
In postpubertal patients, semen analysis can be impaired if the torsion lasts over 24 hours and the testicle is retained.
Patients treated with orchidectomy do not appear to have abnormal semen.5 It is debatable whether this affects subsequent paternity rates.
Testicular torsion treated by untwisting of the testicle involves a period of ischaemia followed by reperfusion. This results in the generation of free radicals.
Experimental studies in rats using in vivo models of testicular reperfusion injury have investigated the use of antioxidants to limit the damage caused by reperfusion following surgery.
A delay in seeking medical attention is one of the main causes of delayed surgery in patients with testicular torsion.
High levels of patient awareness about the disastrous consequences of delayed treatment are therefore crucial to ensuring a high testicular salvage rate.
Delay in diagnosis and referral, or a missed diagnosis, could have medicolegal implications. Therefore, if there is any doubt regarding the diagnosis, onward referral is essential.
1. Barada J, Weingarten J, Cromie W. Testicular salvage and age-related delay in the presentation of testicular torsion. J Urol 1989; 142: 746-8.
2. Bennett S, Nicholson M, Little T. Torsion of the testis: why is the prognosis so poor? BMJ 1987; 294: 824.
3. Anderson J, Williamson R. Testicular torsion in Bristol: a 25-year review. Br J Surg 1988; 75: 988-92.
4. Kravchick S, Cytron S, Leibovici O et al. Color Doppler sonography: its real role in the evaluation of children with highly suspected testicular torsion. Eur Radiol 2001; 11: 1,000-05.
5. Bartsch G, Frank S, Marberger H et al. Testicular torsion: late results with special regard to fertility and endocrine function. J Urol 1980; 124: 375-8.
Contributed by Mr Asif Muneer, senior fellow in urology at University College London Hospital, and Mr David Ralph, consultant urological surgeon at the Institute of Urology, London.