TESTICULAR TORSION

Introduction
Background
Testicular torsion is a true urologic emergency and must be differentiated from other complaints of testicular pain because a delay in diagnosis and management can lead to loss of the testicle. Though testicular torsion can occur at any age, including the prenatal and perinatal periods, it most commonly occurs in adolescent males, and testicular torsion is the most frequent cause of testicle loss in that population.

Pathophysiology
The testicle is typically covered by the tunica vaginalis, a potential space that encompasses the anterior two thirds of the testicle and where fluid from a variety of sources may accumulate. The tunica vaginalis attaches to the posterolateral surface of the testicle and allows for little mobility of the testicle within the scrotum.

In patients who have an inappropriately high attachment of the tunica vaginalis, the testicle can rotate freely on the spermatic cord within the tunica vaginalis (intravaginal testicular torsion). This congenital anomaly, called the bell clapper deformity, results in the long axis of the testicle to become oriented transversely rather than cephalocaudal. This congenital abnormality is present in approximately 12% of males, 40% of which have the abnormality in the contralateral testicle as well.1 The bell clapper deformity allows the testicle to twist spontaneously on the spermatic cord, causing venous occlusion and engorgement, with subsequent arterial ischemia causing infarction of the testicle. Experimental evidence indicates that 720° torsion is required to compromise flow through the testicular artery and result in ischemia.

In the neonatal age group, the testicle frequently has not yet descended into the scrotum, where it becomes attached within the tunica vaginalis. This mobility of the testicle predisposes it to torsion (extravaginal testicular torsion). Inadequate fusion of the testicle to the scrotal wall, moreover, typically occurs within the first 7-10 days of life.

Torsion may be categorized as complete, incomplete, or transient.


Frequency
United States
Incidence of torsion in males younger than 25 years is approximately 1 in 4000.2 Torsion more often involves the left testicle.

Of the cases of testicular torsion that occur in the neonatal population, 70% occur prenatally and 30% occur postnatally.


Mortality/Morbidity
This urologic emergency requires prompt diagnosis, immediate urologic consultation, and rapid definitive operative treatment for salvage of the testicle.

A salvage rate of 90-100% is found in patients who undergo detorsion within 6 hours of pain; the viability rate fell to between 20% and 50% after 12 hours; and 0 to 10% viability if detorsion is delayed greater than 24 hours.3, 2


Sex
Testicular torsion affects males only.

Age
Testicular torsion most often is observed in males younger than 30 years, with most aged 12-18 years. The peak age is 14 years, although a smaller peak also occurs during the first year of life.

Clinical
History
History includes a sudden onset of severe unilateral scrotal pain.
As many as 50% of patients have a history of prior episodes of intermittent testicular pain that has resolved spontaneously (intermittent torsion and detorsion).
Onset of pain can occur more slowly, but this is an uncommon presentation of torsion.
Torsion can occur with activity, be related to trauma in 4-8% of cases2, or develop during sleep.
The historical features suggestive of testicular torsion include the following:
Acute onset of unilateral scrotal pain
Scrotal swelling
Nausea and vomiting: In the pediatric population, nausea and vomiting more commonly accompany acute testicular torsion and have a positive predictive value of greater than 96%.4
Abdominal pain (20-30%)
Fever (16%)
Urinary frequency (4%)
Physical
The physical examination may be difficult to perform, particularly in the case of an ill child.
Involved testicle painful to palpation; frequently elevated in position when compared with the other side
Horizontal lie of the testicle
Enlargement and edema of the testicle; edema involving the entire scrotum
Scrotal erythema
Ipsilateral loss of the cremasteric reflex. The cremasteric reflex is almost always absent in patients with testicular torsion, and its presence may help to distinguish other causes of acute scrotal pain from testicular torsion.5, 6
Usually, no relief of pain upon elevation of scrotum (elevation may improve the pain in epididymitis [Prehn sign])
Fever (uncommon)
Causes
Congenital anomaly; bell clapper deformity
Undescended testicle
Sexual arousal and/or activity
Trauma
Exercise
Active cremasteric reflex
Cold weather


source:emedicine