Testicular torsion

Testicular torsion usually presents with severe testicular pain or pain in the groin and lower abdomen. There is often associated nausea and vomiting. There may be a history of previous, similar episodes of scrotal pain due to prior transient testicular torsion with spontaneous resolution. The impact of testicular torsion on long-term fertility is not yet fully understood. The cause of abnormal sperm function is thought to be due to the following mechanisms: • Immunological theory, also known as "sympathetic orchidopathia": It is thought that following injury to the testicle, the body's immune system is activated to clean up damaged cells. In the process, it creates anti-testicular cell antibodies, or proteins that cross the injured blood-testis barrier and damage both the affected and contralateral testicles. • Reperfusion injury: This type of injury is seen in tissues that have been deprived of blood supply for a prolonged period. • Psychological impact of losing a testicle. ==Risk factors==

Most of those affected with testicular torsion have no prior underlying health problems or predisposing conditions. In this condition, rather than the testes attaching posteriorly to the inner lining of the scrotum by the mesorchium, the mesorchium terminates early and the testis is free floating in the tunica vaginalis. Other anatomic risk factors include a horizontal lie of the testicle or a spermatic cord with a long intrascrotal portion. however, only about 4–8% of cases are the result of trauma. There is thought to be a possible genetic basis for predisposition to torsion, based on multiple published reports of familial testicular torsion. There is controversy about whether cold weather months are associated with an increased risk. ==Pathophysiology==

Testicular torsion occurs when there is a mechanical twisting of the spermatic cord, which suspends the testicle within the scrotum and contains the testicular artery and vein. Twisting of the cord reduces or eliminates blood flow to the testicle. Intermittent testicular torsion Intermittent testicular torsion (ITT) is a less serious but chronic variant of torsion. It is characterized by intermittent scrotal or testicular pain, followed by eventual spontaneous detorsion and resolution of pain. Nausea and vomiting may also occur. Extravagina testicular torsion Torsion occurring outside of the tunica vaginalis, when the testis and gubernaculum can rotate freely, is termed an extravaginal testicular torsion. This type occurs exclusively in newborns, however, newborns can be affected by other testicular torsion variants as well. The mechanism for torsion in the undescended testicle is not fully understood, though it may be due to abnormal contractions of the cremaster muscle, which covers the testicle and spermatic cord and is responsible for raising and lowering the testicle to regulate scrotal temperature. The undescended testicle is also at higher risk for testicular tumor, which, due to the increased weight and size compared to a healthy testicle, can predispose to torsion. ==Diagnosis==

The diagnosis should be made based on the presenting symptoms. Given the treatment implications of testicular torsion, it is important to distinguish testicular torsion from other causes of testicular pain, such as epididymitis, which can present similarly. While both conditions can cause testicular pain, the pain of epididymitis is typically localized to the epididymis at the rear pole of the testicle. Epididymitis also may be characterized by discoloration and swelling of the testis, and fever. The cremasteric reflex in epididymitis usually is present. Testicular torsion, or more probably impending testicular infarction, also can produce a low-grade fever. Prehn's sign, a classic physical exam finding, has been unreliable in distinguishing torsion from other causes of testicular pain, such as epididymitis. The individual usually will not have a fever, though nausea is common. Imaging A Doppler ultrasound scan of the scrotum can identify the absence of blood flow in the twisted testicle and is nearly 90% accurate in diagnosis. Radionuclide scanning (scintigraphy) of the scrotum is the most accurate imaging technique, but it is not routinely available, particularly with the urgency that might be required. The agent of choice for this purpose is technetium-99m pertechnetate. Initially it provides a radionuclide angiogram, followed by a static image after the radionuclide has perfused the tissue. In the healthy patient, initial images show symmetric flow to the testes, and delayed images show uniformly symmetric activity. In testicular torsion, the images may show heterogeneous activity within the affected testicle. ==Treatment==

Testicular torsion is a surgical emergency that requires immediate intervention to restore the flow of blood to the testicle. About 40% of cases result in loss of the testicle. When salvage of the testicle is accomplished, long-term testicular damage is common. Testicular size is often diminished, and injury to the unaffected testicle is common. ==Epidemiology==

Torsion is most frequent among adolescents with about 60% of cases presenting between 10 and 18 years of age. It is the most common cause of rapid onset testicular pain and swelling in males under 18 years old. It occurs in about 1 in 4,000 to 1 per 25,000 males per year before 25 years of age; but it can occur at any age, including infancy. ==See also==