Testicular Trauma 

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. Such injuries are typically seen in males aged 15-40 years.

A thorough history and detailed physical examination are essential for an accurate diagnosis. Scrotal ultrasonography 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 ultrasonography in this situation has been reported to be 93.5% and 100%, respectively. However, in the setting of a clinically apparent hematocele, some authors question the value of a ultrasonographic examination and feel prompt exploration is more appropriate.^[1]

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. However, a recent study has suggested that conservative management is an option when ultrasonography demonstrates an intratesticular hematoma without obvious fracture planes or disruption of the tunica albuginea.^[1]

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.^[2] Operative indications for blunt trauma include suspicion of rupture, expanding hematomas, dislocation refractory to manual reduction, avulsion, and scrotal degloving.

It should be noted, however, following a paradigm shift toward conservative management of renal trauma, one group reported on nonoperative management in a small group of adolescent boys with testicular rupture.^[3] None of the patients required orchiectomy or developed atrophy at 6 months of follow-up. Further investigation is needed before such an approach can be recommended in children or adults.

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. One report even described testicular rupture from a paint ball injury.^[4] Also, one study reported an increased incidence of testicular calcifications in extreme mountain bikers over nonbikers, suggesting repeated testicular trauma in these individuals.^[5]

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 below).

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 of testicular dislocation are the result of motorcycle crashes, and one third involve both testicles. This is related to impact with the fuel tank, and the inguinal region is the most frequent site of displacement.^[6] Additional routes include 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. The image below depicts hematoma in testicular fracture.

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 scanning demonstrating an empty scrotum and displaced testis. The average delay in diagnosis was 19 days.^[7]

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.^[8] 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).

The testis is enveloped by layers of white fibrous connective tissue called the tunica vaginalis and the tunica albuginea. 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 image below depicts a healthy testis.

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 protect the testes 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.

Patients with testicular trauma 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.

Most 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 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. Up to 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.^[9]

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

Scrotal ultrasonography 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 ultrasonography 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.

Indications for scrotal exploration include the following:

• Uncertainty in diagnosis after appropriate clinical and radiographic evaluations
• Clinical findings consistent with testicular injury
• Disruption of the tunica albuginea
• Absence of blood flow on sonograms with Doppler studies

Clinical hematoceles that are expanding or of considerable size (eg, ≥5 cm) should be explored. Collections of smaller size are also often explored, because it has been shown that such practice allows for more optimal pain control and shorter hospital stays.

If the testis is fractured, testicular debridement and surgical closure of the tunica albuginea are necessary.

Penetrating testicular trauma usually requires exploration to ascertain the degree of injury, to assess the integrity of the testis, and to identify and control intratesticular hemorrhage.

Degloving injuries are another indication for operative evaluation and often require debridement. Skin closure may or may not be possible in the acute setting.

The absence of blood flow on ultrasonography may represent spermatic cord torsion, avulsion, or infarction.

To properly evaluate and treat testicular injuries, a thorough knowledge of scrotal and testicular anatomy is required.

The outermost layer of the scrotum is the scrotal skin. The next most superficial layer is the dartos muscle/fascia, which is contiguous with the Scarpa fascia of the abdomen, the Colles fascia of the perineum, and the dartos fascia of the penis. The dartos layer is followed by the external, middle, and internal spermatic fasciae, which are contiguous with the external oblique, internal oblique, and transversalis fasciae, respectively. The middle spermatic fascia forms the cremasteric muscle of the spermatic cord. In most cases, the testicle is tethered to the scrotum inferiorly by the gubernaculum.

The next layer is the tunica vaginalis, which is composed of an outer (parietal) layer and an inner (visceral) layer. The tunica albuginea is a tough, white, fibrous, capsulelike layer surrounding the seminiferous tubules of the testis. The visceral layer of the tunica vaginalis adheres to this layer.

Immediately beneath the tunica albuginea is the final layer, the tunica vascularis, which contains the arterial blood supply to the seminiferous tubules. The tunica albuginea extends inward posteriorly to form the mediastinum testis, the point where vessels and ducts traverse the testicular capsule. The epididymis attaches posterolaterally.

Blood supply to the testes is threefold.

• The testicular artery is the principal artery, rising from the aorta, just below the renal artery.
• The cremasteric artery is a branch of the inferior epigastric artery.
• The deferential artery is a branch of the superior vesical artery.

These 3 vessels collateralize and anastomose in the spermatic cord and near the epididymis.

Surgical therapy is unnecessary in cases of minor trauma in which the testes are unequivocally spared and the scrotum has not been violated.

Documented testicular injuries necessitate immediate repair. Inappropriately protracted expectant management promotes testicular infection, atrophy, and necrosis. Delay in repair may herald the loss of spermatogenesis and hormonal functions.