Testicular torsion

Testicular torsion is the sudden twisting of the spermatic cord within the scrotum. It most commonly affects neonates and young men. Because of the risk of ischemia and possible infarction of the testis, it is considered a urological emergency. Testicular torsion is characterized by sudden-onset unilateral testicular pain, which may radiate to the lower abdomen, with nausea and vomiting. Clinical findings include a high-riding testis with an absent cremasteric reflex. Imaging with duplex ultrasound of the scrotum may be required if the clinical diagnosis is in doubt. If testicular torsion is suspected, prompt surgical exploration within six hours of symptom onset is essential to salvage the testis. Important differential diagnoses, e.g., orchitis and epididymitis, should be ruled out before initiating treatment.

• Peak incidence: neonatal period (first 30 days of life) and during puberty (10–14 years) ^[1]
• Prevalence
  • 3.8 per 100,000 male individuals under the age of 18 (two-thirds of cases occur between 12 and 18 years of age) ^[2]
  • Accounts for 10–15% of acute scrotal illness in children within the United States ^[3]

Epidemiological data refers to the US, unless otherwise specified.

• Idiopathic ^[3]
  • Proposed causes include bell clapper deformity (intravaginal torsion; see "Pathophysiology" below) and a long mesorchium.
  • In fetuses and neonates: extravaginal torsion of the entire tunica vaginalis
• Iatrogenic
• Occurs as a result of trauma in very rare cases ^[4]
• Predisposing factors, especially in adults: testicular malignancy

• Abrupt onset of severe testicular pain and/or pain in the lower abdomen
• Typically swollen and tender testis and/or lower abdominal tenderness ^[8]
• Nausea and vomiting
• Abnormal position of the testis
  • Scrotal elevation (high-riding testis)
  • Abnormal transverse position
  • Possible undescended testes (predisposes to testicular torsion) ^[9]
• Absent cremasteric reflex
• Negative Prehn sign
• In neonates
  • Possible absent testis
  • Firm, painless scrotal mass
  • Possible acute inflammation: swollen, erythematous (or blue discolored in venous engorgement), and tender hemiscrotum

Sudden, severe, unilateral scrotal pain in a patient with a tender, abnormally positioned testis on examination should be managed as testicular torsion until proven otherwise.

References:^[3]

Testicular torsion is typically a clinical diagnosis. Imaging is not routinely indicated but may be considered in patients with atypical clinical features. Because of the significant risk of infertility, diagnostic workup should not delay the management of suspected testicular torsion.

Imaging

• Duplex ultrasound of the scrotum ^[10][11][12]
  • Indication: inconclusive clinical findings ^[10]
  • Characteristic findings ^[12]
    • Twisting of spermatic cord (whirlpool sign)
    • Reduced or absent blood flow to/from the affected testis
    • Heterogeneous appearance of testicular parenchyma indicates testicular necrosis.
• Radionuclide imaging ^[3][13]
  • Indications
    • Inconclusive clinical findings
    • Evaluate for epididymitis
  • Characteristic findings
    • Testicular torsion
      • Areas that do not absorb radionuclide as a result of decreased blood flow to the affected testis (“Cold spots”)
      • Asymmetric blood flow
    • Epididymitis: areas where there is increased radionuclide absorption as a result of increased blood flow in inflammation (“Hot spots”)

Surgical intervention is recommended for suspected testicular torsion, regardless of radiological findings.

Laboratory studies

• Not routinely indicated
• Urinalysis ^[10]
  • Indications: rule out epididymitis
  • Findings: leukocytes and erythrocytes in the urine suggest epididymitis but do not exclude torsion (see epididymitis).

Differential diagnosis of scrotal pain
Disorder	History	Examination	Laboratory studies
Testicular torsion	Sudden onset Unilateral painful testis/lower abdomen Nausea or vomiting	Swollen, edematous, tender testis Abnormal position of testis (e.g., transverse lie, scrotal elevation) Negative Prehn sign Absent cremasteric reflex	Normal inflammatory markers Normal urinalysis
Epididymitis	Gradual onset (e.g., < 6 weeks if acute, ≥ 6 weeks if chronic) [14] Painful swelling with possible induration Possible history of urethral discharge Fever, dysuria, urinary frequency	Very tender (physical examination is painful) Positive Prehn sign Positive cremasteric reflex	Increase in generalized inflammatory markers Possible pyuria during urinalysis
Testicular tumor	Slow progression (e.g., weeks to months) Usually painless mass (however, the patient may experience a dull ache or describe a “heavy” sensation in the testis)	Easy palpation of solid mass Possible manifestations of metastatic disease (e.g., distant lymphadenopathy, chest pain, gastrointestinal symptoms) Possible swelling of the ipsilateral lower limb (venous engorgement due to obstruction)	Possible increase in serum tumor markers (e.g., alpha-fetoprotein)
Torsion of testicular appendage (hydatid of Morgagni)	Insidious onset of unilateral scrotal pain Usually seen in boys 3–5 years of age	Tender testis May manifest with blue dot sign	Typically normal inflammatory markers Typically normal urinalysis

Torsion of testicular appendage (hydatid of Morgagni)

• Description: an embryological remnant on the upper pole of the testes or at the epididymis (the remnant of the Mullerian duct) that has the potential to rotate
• Clinical features: Symptoms resemble acute testicular torsion.
  • Typically seen in boys 3–5 years of age
  • Insidious unilateral scrotal tenderness
  • Blue dot sign (infarction of the hydatid of Morgagni that appears blue through the scrotal skin)
• Imaging: Doppler ultrasound may show an enlarged testicular appendix and/or mild hydrocele with preserved testicular blood flow.
• Management
  • A conservative approach with NSAIDs may be considered.
  • If the diagnosis is in doubt, surgical intervention is required to examine the testes.

References:^[3][15]

The differential diagnoses listed here are not exhaustive.

Testicular torsion is a medical emergency and should ideally be treated within 6 hours of the onset of symptoms for the best chance of testicular salvage. Manual detorsion in the ER may be attempted prior to surgery for immediate pain relief, but should not delay transferring the patient to the OR.

Exploratory surgery ^[10][3]

• Indication: suspected testicular torsion
• Timing: ideally, within 6 hours of symptom onset ^[3]
• Procedure
  • Immediate surgical exploration of the scrotum with reduction (untwisting) and orchidopexy of the affected testis
  • Orchidopexy of the contralateral testis is recommended because the risk of testicular torsion on the contralateral side increases with previous or current testicular torsion.
  • Orchiectomy if the testis is grossly necrotic or nonviable

Manual detorsion ^[3]

• Indication: : may be attempted prior to surgery for immediate pain relief or if surgery is not immediately available
• Procedure
  • Rotate the testis laterally toward the thigh ; two-thirds of torsions occur toward the midline.
  • If lateral rotation does not provide symptom relief, rotate the testis toward the midline; one-third of torsions occur laterally. ^[16]
  • Surgery should still be performed in all patients to resolve any possible degree of remaining torsion and to prevent recurrence. ^[10][10]

Because of the risk of infertility, surgical exploration of the scrotum is recommended in any patient suspected of having testicular torsion, even if manual detorsion has been attempted.