Testicular Torsion

Pathophysiology

During development, the testicle becomes invested by the tunica vaginalis, to which it is fixed inferiorly by the gubernaculum testis.  If this fixation is insufficient, then the testis may lie in a transverse position known as the “bell-clapper” deformity, which makes the testis more prone to twisting on the spermatic cord within the tunica vaginalis.  This deformity, however, is not necessary for torsion to occur.  The twisting of the testis within the tunica vaginalis, or so-called “intravaginal” twisting, is the torsion referred to in testicular torsion.  It leads to venous compression, edema, and ultimately ischemia from arterial occlusion. 

During the neonatal period, torsion is defined as “extravaginal” because the tunica vaginalis is not well fixed to the scrotal wall so the tunica vaginalis investment twists along with the testis.  The consequences are the same.  Torsion has a bimodal incidence – a small peak in the neonatal period, and a large one during puberty, however it can occur at any time.  The increased incidence during puberty is thought to be secondary to the increased weight of the testes.

 

Presentation

Usually there is an acute onset of pain in the scrotum or testis, however the patient may complain of inguinal or lower abdominal pain.  Associated nausea and vomiting is very common. The pain will be constant unless there is torsing and detorsing of the testicle.  There is usually no history of trauma, but there is often a history of previous testicular pain that resolved by itself.

Common physical findings: 

  1. Edematous scrotum and a tender, swollen, elevated testis. A reactive hydrocele may be present.
  2. Absent cremasteric reflex (although this is not specific)
  3. Prehn's sign - Elevation of the testicle relieves pain in epididymitis, not in torsion. However, this alone is not sufficient to rule out torsion. 

 

Diagnosis

Any swelling in the scrotum is torsion of the testis until proven otherwise. The child must be seen immediately because time is critical in trying to salvage the testis. Usually the diagnosis is made clinically.  A color Doppler ultrasound or a nuclear scan may be used if the diagnosis is uncertain, but only if they will not significantly delay treatment.   Doppler is less useful in pre-pubertal patients because baseline blood flow to the testis is less.  The scans may be equivocal and if not readily available, the child should be taken to the OR.

 

Management

Immediately consultation to a urologist is necessary. Treatment is surgical detorsion and fixation of the testis in the scrotum on both sides (bilateral orchiopexy). Viability of the testis is based on gross inspection at the time of surgery and the testis’ appearance before and after detorsion. If there is no sign of viability, surgeons will remove the testis. 

As a general guideline, if duration of torsion is less than 6 hrs: 100% viability; 12 hrs: 20% viability; 24 hrs: 0% viability. However, surgery should never be delayed on the assumption of nonviability.  Manual detorsion by an experienced clinician can be attempted if there is no scrotal edema with appropriate sedation and analgesia.  Classic teaching is that the testis should be rotated outward (like opening a book), however up to one third of testis are twisted the other way.

 

Prognosis

This will depend on the duration of torsion and the viability of the testis after detorsion has been performed.  Some authors report decreased fertility when a testis is left in situ following a unilateral torsion.  This may be due to immune-mediated damage to the contralateral testis.  This issue remains controversial.

 

Differential Diagnosis

  1. Torsion of the appendices of the testis. The appendix testis is a pedunculated vestigial structure on the anterosuperior aspect of the testis, which can twist on its stalk and cause pain.  It occurs most often in boys aged 7-12 yrs.  It causes acute onset pain but is typically not as severe as in testicular torsion. The tenderness is often localized to a palpable mass at the inferior or superior pole.  Most often a positive cremasteric reflex and affected side is not elevated. Scrotal discoloration may occur and there may be the "blue dot" sign. It may be difficult to differentiate and a scan may help, which would show normal blood flow to the testis.   May need to surgically explore to rule out a torsion of the testis.
  2. Epididymitis- The scrotum is not as swollen and there is often an accompanying history of frequency, dysuria, urethral discharge, fever. The testicle should have a vertical lie.  Pain onset can be acute, but also may be sub-acute.  The age is similar to torsion of the testis.  Cremasteric reflex should be present, and classically the pain is reduced on elevation of the testis.  An abnormal UA may be present, but this is not sensitive.
  3. Orchitis- usually more gradual onset of symptoms. May have scrotal edema and discoloration. Viral etiologies most common, but can also be bacterial (brucellosis).
  4. Incarcerated inguinal hernia – Pain with a scrotal mass. Bowel sounds may be present.
  5. HSP – acute or insidious onset of pain. Look for other signs of HSP.  Doppler will differentiate.
  6. Trauma – Elicit corresponding history.  Doppler may help assess degree of injury.
  7. Tumor – look for testicular enlargement in context of insidious onset of pain
  8. Nonspecific scrotal pain – can only call it this if pain is mild

 

References

  1. Baker LA et al. An Analysis of Clinical Outcomes Using Color Doppler Testicular Ultrasound for Testicular Torsion. Pediatrics. 2000; 105(3):604-607.
  2. Gatti, John M., and J. Patrick Murphy. Acute testicular disorders. Pediatrics in Review 29.7 (2008): 235-241.
  3. Kadish HA and Bolte RG. A Retrospective Review of Pediatric Patients with Epidymitis, Testicular Torsion and Torsion of Testicular Appendages. Pediatrics. 1998; 102(1):73-76.
  4. Adelman W and Joffe Alain.  The Adolescent with the Painful Scrotum.  Contemporary Pediatrics March 2000
  5. Mansbach, J et al. Testicular Torsion and Risk Factors for Orchiectomy.  Arch Pediatr Adoleesc Med Vol 159 Dec 2005
  6. Huang, Wei‐Yi, et al. The Incidence Rate and Characteristics in Patients with Testicular Torsion: A Nationwide, Population‐based Study. Acta Paediatrica (2013).

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