Testicular Torsion

Etiology

The majority of cases occur in younger patients (< 25 years old) and are usually due to a congenital abnormality of the processus vaginalis. The history of onset may be spontaneous, exertional, or, in fewer instances, associated with trauma. Testicular torsion accounts for a significant number of scrotal complaints that present to the emergency department.

Testicular torsion is caused by the twisting of the blood supply and spermatic cord. The tunica vaginalis is usually solidly adhered to the posterolateral aspect of the testicle, and within it, the spermatic cord is not mobile. If the attachment of the tunica vaginalis is high, then this allows the spermatic cord to twist inside, leading to intravaginal torsion. This defect is referred to as the bell clapper deformity and is bilateral in at least 2/5ths of cases.

On the other hand, neonates tend to develop extravaginal torsion. This occurs because the tunica vaginalis has not adhered to the gubernaculum, and thus, both the tunica vaginalis and spermatic cord are prone to torsion. This pathology can occur weeks or months prior to birth and is treated in a different manner. However, it is important to know that neonates can also present with intravaginal torsion.

Testicular torsion has been known to occur in the presence of testicular malignancy in adults.

Epidemiology

The majority of cases occur in the adolescent age range (during periods of growth) but can occur at any age as well as pre- or perinatal. Testicular torsion is the most significant cause of testicular loss.

Pathophysiology

As the testicle twists around the spermatic cord, venous blood flow is cut off, leading to venous congestion and ischemia of the testicle. The testicle will become tender, swollen, and possibly erythematous. As the testicle further twists, the arterial blood supply is cut off, which leads to further testicular ischemia and, eventually, necrosis. [4]

In most individuals, the testicle rotates between 90-180 degrees and compromises blood flow. Complete torsion is rare and quickly decreases the viability of the testes. Salvage is possible if the torsion is less than 8 hours, but rare if more than 24 hours have elapsed.

History and Physical

Testicular torsion often presents as an abrupt onset of unilateral scrotal pain. The pain may be constant or intermittent but not positional. The patient may have associated symptoms of nausea or vomiting. There may be associated lower abdominal and inguinal pain, or alternatively, these may be the presenting complaint rather than scrotal pain. 

The testicle may be in an abnormal or transverse lie and maybe in a high position. The testicle may be swollen, erythematous, and have an absence of the normal cremasteric reflex; however, it should be noted that the presence or absence of the cremasteric reflex is not as sensitive as once thought. Additionally, the cremasteric reflex is unreliable in young patients, especially those under one year old. 

The Prehn sign is not reliable for predicting torsion (relief of pain with testicle elevation).

Torsion of the testicular appendages is more common and not dangerous. During early onset, this may be differentiated from testicular torsion by maximal tenderness to palpation near the head of the epididymis or testis, an isolated tender nodule, and/or a blue dot appearance on the testis. The characteristic blue dot is due to the cyanotic torsed appendage. The testicular appendage tends to calcify and degenerate over two weeks, and typically, no surgical intervention is required. 

Other differential diagnoses to be considered are epididymitis, orchitis, inguinal hernia, symptomatic hydrocele, testicular necrosis of other etiology, and scrotal hematoma. 

Evaluation

The TWIST scoring system is often used to determine the presence of testicular torsion. It has been validated in several studies in ruling out torsion. The TWIST tool includes:

Hard testis - 2

Swelling - 2

Nausea/vomiting - 1

Absent cremasteric reflex - 1

High riding testis - 1

The higher the score, the greater the probability that the patient has torsion. Ultrasound is recommended for those with low scores. Those with high TWIST scores can be taken for surgery without ultrasound.

Ultrasound is the primary diagnostic modality beyond the physical exam. Ultrasound for testicular torsion is approximately 93% sensitive and 100% specific. Trained sonographers should perform this exam in a timely manner. The point-of-care ultrasound technique to evaluate the testicle involves the high-frequency transducer (5 to 10 MHz), ample ultrasound gel, and proper patient positioning. The process is described in brief below: 

1. Place the patient supine and frog-legged with a towel under the scrotum for support. Using ample gel and minimal pressure, evaluate the unaffected testicle first.  
2. Scan the testicle in its entirety in both the transverse and longitudinal planes. Scan with grayscale first while noting the presence of fluid collections and testicular texture. A normal testicular is around 4 x 3 x 2.5cm. In the longitudinal plan or long axis, the testicle appears as an oval structure with homogenous echotexture and smooth, rounded borders. In the transverse plane or short axis, the testicle appears as a circular structure with homogenous echotexture and smooth, rounded borders. Side-by-side comparison of the testicles is critical to evaluate for size, fluid collections, changes of echotexture, and discrepancies of color Doppler. If the testicle is torsed, there will often be a hydrocele present with a testicle with reduced color or power flow.

Color flow Doppler must be applied to both the affected and unaffected testicle of the patient. Begin with the unaffected testicle to gain a sense of what normal vascular flow looks like in this particular patient. Power Doppler is useful in the evaluation of testicular vascular flow as well. Power Doppler has greater sensitivity for vascular flow but does not allow the examiner to discern between arterial and venous flow.  

Doppler can be employed to evaluate for both venous and arterial flow by placing the Doppler gate on areas of vascular flow and evaluating for both venous and arterial Doppler waveforms. Arterial waveforms will have large spikes due to the peaks of arterial blood pressure, whereas venous waveforms typically appear as plateaus of Doppler flow. Applying Doppler and checking for both venous and arterial flow can further demonstrate the severity of the torsion. The same technique will be employed on the affected testicle. 

Assessment for pyuria with urine analysis is typically part of the acute scrotal pain workup. The presence of pyuria is consistent with epididymitis, orchitis, or urinary tract infection but does not rule out the possibility of testicular torsion. [5][6]

Treatment / Management

Ultrasound is not a perfect test for testicular torsion, especially in the very young. For example, 40% of neonatal testicles may have no apparent color flow Doppler. If the clinical concern is high, seek urologic surgery consultation immediately. Any delay in treatment could result in testicular necrosis and loss. The typical window of opportunity for surgical intervention and testicular salvage is 6 hours from the onset of pain. Therefore, early urologic surgery consultation upon presentation may be critical even in the absence of confirmatory testing. 

Manual detorsion should be attempted if urological intervention is not immediately available. The abnormal testicle should be rotated in a medial to lateral direction (open book) 180 degrees and then evaluated for pain relief. If the pain is increased, consider rotating the testicle in the opposite direction. Ultrasound can also be used serially to evaluate for return of blood flow at the bedside. If unsuccessful, further manual detorsion may be attempted as the testicle can twist 180 degrees.[4][7][8](A1)

In neonates, bilateral scrotal exploration is done. Contralateral orchiopexy is always done to prevent future torsion. Patients who require an orchiectomy for a non-viable testis usually have a testicular prosthesis inserted. The prosthesis is usually inserted 4-6 months after the initial surgery to allow for the inflammation to subside

Differential Diagnosis

• Testis tumor
• Epididymitis
• Hydrocele
• Traumatic hematoma
• Orchitis

Prognosis

Over the years, there has been a marked improvement in the salvage of the testes following torsion. However, poor results still occur, especially in African Americans, young patients, and those who lack health insurance. The best results are obtained if the surgery is done within 8 hours of symptoms. However, recurrence can also occur after orchiopexy.

Complications

• Loss of testis
• Infection
• Infertility
• Cosmetic deformity
• Loss or diminished exocrine and endocrine function in men