Excerpt from Testicular Trauma

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Despite the vulnerable position of the testicles, testicular trauma is relatively uncommon. Mobility of the scrotum may be one reason severe injury is rare. Given the importance of preserving fertility, traumatic injuries of the testicle deserve careful attention.

Testicular injuries can be divided into 3 broad categories based on the mechanism of injury. These categories include (1) blunt trauma, (2) penetrating trauma, and (3) degloving trauma. Injuries are typically seen in males aged 15-40 years.

A thorough history and detailed physical examination are essential for an accurate diagnosis. Scrotal ultrasound with Doppler flow evaluation is particularly helpful in determining the nature and extent of injury. This is especially true in blunt trauma cases, given the difficulty of scrotal examination and the repercussions of missing a testicular rupture. The sensitivity and specificity of ultrasound in this situation has been reported to be 93.5% and 100%, respectively.

Penetrating testicular trauma usually requires scrotal exploration to determine the severity of testicular injury, to assess the structural integrity of the testis, and to control intrascrotal hemorrhage. If the tunica albuginea is violated, early surgical exploration, debridement, and closure of the tunica albuginea are necessary.

Blunt injuries are encountered more often than penetrating injuries and are usually unilateral, whereas penetrating injuries involve both testes in a third of cases. Most cases of blunt trauma to the testicles are minor and usually require only conservative therapy. However, in one study, Buckley and McAninch (2006) reported that 46% of patients presenting with blunt scrotal trauma underwent surgical exploration and were found to have rupture of the tunica albuginea.¹ Operative indications for blunt trauma include suspicion of rupture, expanding hematomas, dislocation refractory to manual reduction, avulsion, and scrotal degloving.

Problem

Testicular trauma is defined as any injury sustained by the testicle. Types of injuries include blunt, penetrating, or degloving.

Blunt trauma refers to injuries sustained from objects applied with any significant force to the scrotum and testicles. This can occur with various types of activity. Examples include a kick to the groin or a baseball injury. A report even exists of testicular rupture from a paint ball injury.² Also, one study reported an increased incidence of testicular calcifications in extreme mountain bikers over nonbikers, suggesting repeated testicular trauma in these individuals.³

Penetrating trauma refers to injuries sustained from sharp objects or high-velocity missiles. Examples include gunshot and stab wounds.

Degloving injuries (or avulsion injuries) are less common. With these, scrotal skin is sheared off, for example, when a testicle becomes trapped in heavy machinery.

Testicular rupture or fractured testis refers to a rip or tear in the tunica albuginea resulting in extrusion of the testicular contents (see Image 2).

Testicular dislocation is an uncommon and sometimes easily overlooked event that refers to a testis that has been relocated from its orthotopic position to another location secondary to blunt trauma. Indirect inguinal hernias and atrophic testicles may be predisposing factors. Most cases are the result of motorcycle crashes, and one third involve both testicles. Possible routes include superficial inguinal, pubic, preputial, acetabular, canalicular, penile, intra-abdominal, retrovesical, perineal, and crural dislocations. Diagnosis should be followed by early treatment in the form of manual closed reduction and surgical fixation if closed reduction is unsuccessful.

Genital self-mutilation is another potential source of testicular trauma. The offending patient is often psychotic, although nonpsychotic patients practicing autoeroticism and motivated yet desperate transsexuals may find themselves requiring an urgent urologic consultation. Most cases of genital self-mutilation involve men castrating themselves. If the patients seek care promptly and the testicles are vital, reimplantation may be considered.

Frequency

Testicular trauma is relatively uncommon. Blunt trauma accounts for approximately 85% of cases, and penetrating trauma accounts for 15%. As many as 80% of hematoceles (blood in the tunica vaginalis) are associated with testicular rupture (see Image 3).

Blunt testicular injuries can be managed either medically or surgically, depending on the clinical presentation. Early surgical intervention for blunt trauma is associated with higher salvage rates (94% vs 79%).

Testicular dislocation is seen in less than 0.5% of cases of abdominal trauma. One retrospective review of emergency department records found that all instances were missed initially, even with CT demonstrating an empty scrotum and displaced testis. The average delay in diagnosis was 19 days.⁴

Etiology

The most common cause of blunt testicular trauma is sports injuries. For example, a study of rugby players in Australia and New South Wales from 1980 to 1993 revealed 14 players with testicular injuries, with the most unfortunate losing both testicles. However, the risk of sports-related testicular injury in American children is likely less than previously suspected. Wan et al (2003) reviewed the National Pediatric Trauma Registry for all 50 states and referenced commonly played contact sports. Of 5,439 reported sports injuries, there were no reported testicular injuries.⁵ The American Academy of Pediatrics Committee on Sports Medicine and Fitness gives an "unqualified yes" to the question of whether or not a boy with only one testicle can play sports. Protective cups may be required in some instances.

The second most common cause of testicular trauma is a kick to the groin. Less common etiologies include motor vehicle accidents, falls, and straddle injuries.

The most common cause of penetrating testicular injuries is a gunshot wound to the genital area. Other causes include stab wounds, self-mutilation, animal bites (usually dog), and emasculation.

The most common cause of degloving testicular injuries is accidents incurred while operating heavy machinery (eg, industrial or farming accidents).

Pathophysiology

The testis is enveloped by layers of white fibrous connective tissue called the tunica vaginalis and the tunica albuginea (see Image 1). The tunica albuginea is the visceral layer that covers the testis, and the tunica vaginalis is the parietal layer that lines the hydrocele sac.

The tunica albuginea is the layer that is violated during a testicular rupture. Approximately 50 kg of force is required to rupture the testicle. A tear in the tunica albuginea leads to extrusion of the seminiferous tubules and allows an intratesticular hemorrhage to escape into the tunica vaginalis. This is referred to as a hematocele. Disruption of the tunica vaginalis or extension to the epididymis leads to bleeding into the scrotal wall, resulting in a scrotal hematoma.

Two factors allow testes to be protected from minor external trauma. First, a thin layer of serous fluid (ie, physiologic hydrocele) separates the tunica albuginea from the tunica vaginalis and allows the testis to slide freely within the scrotal sac. Second, the testes are suspended within the scrotum by the spermatic cord, allowing them to move freely within the genital area. In cases of penetrating trauma or severe blunt trauma, these protective features are insufficient to prevent injury to the testis proper.

Clinical

Patients typically present to the emergency department with a straightforward history of injury (eg, sports injury, kick to the groin, gunshot wound) soon after the event occurs.

Patients who have sustained severe blunt trauma usually exhibit symptoms of extreme scrotal pain, frequently associated with nausea and vomiting. When evaluating a patient with a clinical history of only minor trauma, do not overlook the possibility of testicular torsion or epididymitis. Physical examination often reveals a swollen, severely tender testicle with a visible hematoma. Scrotal or perineal ecchymosis may be present. Bilateral testicular examination and perineal examination should always be performed to rule out associated pathologies. However, because of the severe pain the patient experiences, performing a thorough examination is often difficult, and radiologic evaluation or surgical exploration may be required.

The majority of blunt testicular injuries are unilateral and isolated (ie, without other associated injuries). The absence of scrotal swelling and hematoma may indicate a relatively benign injury. Additional imaging tests or scrotal exploration is required if testicular rupture is suggested because of clinical findings or when a patient experiences pain out of proportion to the physical examination findings. Blunt trauma to the testes may manifest itself as a hematocele or a ruptured testis. The complete absence of pain in a patient with scrotal swelling and hematoma raises the possibility of testicular infarction or spermatic cord torsion.

For penetrating injuries, determine the entrance and exit sites of the wound. As many as 75% of men with penetrating injuries to the genitalia demonstrate additional associated injuries. Carefully examine the contralateral hemiscrotum and the perineal area. Rule out injuries to the contralateral testicle, bulbar urethra, and rectum. Also evaluate the femoral vessels, as major vascular insult in the thigh region is the most commonly reported associated injury. Although uncommon, vascular injury subsequently leading to an ischemic testis has been reported.

Using universal precautions when evaluating these injuries is important. One review of 40 men with penetrating trauma revealed that 38% tested positive for hepatitis B, hepatitis C, or both. Furthermore, according to Cline et al in 1998, 60% of these patients were legally intoxicated at the time of injury.⁶

Screening urinalysis is an important adjunct to the physical examination to rule out urinary tract infection or epididymo-orchitis.

Scrotal ultrasound imaging with Doppler studies is valuable for diagnosing and staging testicular injuries. The presence of a disrupted tunica albuginea is pathognomonic for testicular rupture. A scrotal hematoma often has associated scrotal skin thickening.

Perform Doppler studies during the scrotal ultrasound because they provide information on the vascular status of the testes. Blood flow to the testis indicates that the vascular pedicle is intact. An absence of flow implies that a torsion or devascularizing injury has occurred to the spermatic cord.

Other imaging studies, such as nuclear imaging or MRI, may be used to obtain additional information in equivocal cases. However, the definitive diagnosis of testicular rupture is made in the operating room, and time is a factor in testicular preservation. Scrotal exploration is truly the best diagnostic tool for any equivocal testicular trauma.

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