Pediatric Testicular Torsion

The normal testis lies suspended in the scrotum, with the visceral tunica vaginalis wrapping the anterior, inferior, superior, and mediolateral margins, leaving the posterior surface adherent to the surrounding scrotal soft tissues. The testicular arteries arise from the abdominal aorta and pass inferolaterally through the retroperitoneum to the internal inguinal ring, where they meet the vasa deferentia and enter the inguinal canal.

The spermatic cord (artery, vein, vas, and supporting structures) passes through the canal, out the external inguinal ring, over the pubic tubercle, and into the scrotum, where it meets the testis.

Testicular torsion can take place either inside the tunica vaginalis (intravaginal) or outside it (extravaginal). The distinction is important because the two forms of torsion are associated with different ages of presentation and etiologies. Intravaginal testicular torsion (see the image below) is far more common and represents almost all torsion events in older boys. In a minority, a predisposing factor such as horizontal-lie/bell-clapper deformity makes the opposite testis prone to torsion.

Extravaginal testicular torsion is commonly seen in perinatal cases. Hence, the diagnosis is often made late, long after the torsion event has taken place. The tunica vaginalis takes about 6 weeks after birth to adhere to the surrounding tissues; this may explain the preponderance of the condition in neonates. High birth weight, difficult labor, breech presentation, and overreactive cremasteric reflex have been proposed as possible causes for perinatal torsion.[5, 6]

Testicular torsion is classically described as involving a medial rotation; however, in as many as one third of cases, a lateral rotation has been described.[7, 8] When manual detorsion is contemplated, the testis is typically rotated laterally ("opening the book"); however, if the testis is already laterally rotated, this maneuver worsens the condition. For this reason, manual detorsion is not a commonly performed procedure.

A rotational twisting of the spermatic cord is the basis of all torsion events. When the twist is sufficient to obstruct arterial inflow (and prevent venous blood return), testicular ischemia results, most likely as a consequence of increased intratesticular pressure. If the duration of ischemia is long enough, infarction (loss of testicular tissue) results. Lesser degrees of cord twisting may result in obstruction of venous outflow, causing congestion and swelling of the testis without frank infarction.

Unfortunately, no reliable indicator for risk of torsion has been identified. Numerous factors have been observed in association with torsion, but none can be used to predict torsion risk in a clinical setting.[9, 10]

Bell-clapper deformity

In this anatomic variant, the testis hangs freely within parietal tunica vaginalis secondary to an extension of the tunica high onto the spermatic cord. This extension allows the testis to rotate easily within the tunica because of the lack of normal fixation of the posterior testis to the scrotal tissues.

The bell-clapper deformity is often noted at the time of exploration in older children and adolescents with testicular torsion. The anomaly is seen in 12% of males in cadaveric studies and is often bilateral, being the reason behind the surgical fixation of the uninvolved testis in a proven case of torsion testis.[11]

Pubertal changes

The increased incidence in torsion around the time of puberty has led to speculation regarding the role of pubertal changes in torsion risk. Increased testosterone levels at puberty result in an increased testicular volume and mass. These increases could predispose the testis to torsion because of increased movement around the axis of the cord.

The cord’s torsional rigidity and other resistances, which tend to limit the angle of rotation, may increase less markedly with growth and development. Thus, normal physical activity may result in angular momentum sufficient to easily overcome the opposing resistances, allowing complete testicular torsion.[5]

Anatomic abnormalities

Various anatomic abnormalities of the testis are associated with torsion. The most significant of these is cryptorchidism (see the image below). Cryptorchid testes are at significantly higher risk for torsion than scrotal testes are.[12] Other anatomic abnormalities that may predispose to torsion include a horizontal lie of the testes, polyorchidism,[13] and epididymal anomalies.[14]

Physical activities

In some cases, specific physical activities or events (eg, sports, weight training, and trauma) appear to induce an episode of torsion, perhaps by way of a sudden cremasteric reflex. Epidemiologic studies have shown that testicular torsion is more common in winter months and in northern latitudes, prompting speculation that cold-induced cremasteric contraction may play a role in the development of torsion.[15]

Tunica and scrotal tissue adhesion

In the newborn, the scrotal parietal tunica vaginalis has not yet fully adhered to the outer tissues of the scrotum. Thus, the entire testes, tunica vaginalis, and gubernaculum may twist together within the scrotum, resulting in an extravaginal torsion. This is the most common form of torsion in the perinatal period. (See the image below.) Because the adhesion between the tunica and scrotal tissues is bilaterally deficient, these infants are at risk for bilateral torsion events (either synchronous or metachronous).[5, 16]

Testicular torsion is one of the more common acute pediatric surgical conditions, though few studies have documented the precise incidence.

In 1976, a study from the United Kingdom reported the annual incidence of testicular torsion as 1 case per 4000 in males younger than 25 years.[17]  A 2011 analysis using data from the Healthcare Cost and Utilization Project Kids' Inpatient Database found the yearly incidence of testicular torsion to be 3.8 per 100,000 in patients younger than 18 years.[18] A 2021 study found that testicular torsion occurring in the first month of life (neonatal or perinatal testicular torsion) occurred at a rate of 6.1 per 100,000 live births.[19]

Successful salvage of the torsed testis is directly related to the time elapsed from the onset of ischemia.[20, 21] If exploration is performed within 4-6 hours of symptom onset, salvage rates may approach 90%; with delayed intervention, however, these rates drop dramatically—to 50% at 12 hours after symptom onset and to almost 10% after 24 hours. In contrast, perinatal testicular torsion almost always results in loss of the involved testis (salvage rate, < 5%).[22]

In a survey by Bennett et al, 55% of boys with testicular torsion (age range, 3 months to 16 years) had infarction with testis loss at scrotal exploration.[23] The main reason for the testicular loss was excessive delay before seeking medical attention, which was usually attributed to the patient or his parents. Survey data have suggested that most boys do not think it is necessary to seek medical advice for testicular swelling, and a large minority do not think it is necessary to seek medical advice for testicular swelling with pain.[24]

Overall, the causes for testicular loss can be summed up as follows[2] :

• Lack of patient awareness or denial and subsequent delay in presentation (58%)
• Misdiagnosis by physician resulting in missed torsion (29%)
• Delay in treatment (13%)

Tryfonas et al reported that the results of testicular atrophy correlated with duration of symptoms and operative findings.[25] In all cases of surgical detorsion where torsion lasted longer than 24 hours and the viability of the testis was questionable, subsequent atrophy occurred.

Reduced fertility is a possible long-term complication of testicular torsion.[26] It may be related to ischemia-reperfusion injury that damages the blood-testis barrier, with resulting antisperm antibody production. A study in the rat model by Ozkan et al found that serum inhibin B levels decrease after unilateral testicular torsion, suggesting contralateral testicular damage.[27] In humans, serum inhibin B levels function as a useful marker of testicular function, in that they reflect Sertoli cell function and spermatogenesis.

A study by Puri et al in 18 men who had undergone testicular torsion 7-23 years previously found the following[28] :

• Five patients had fathered one or more children
• Ten patients had normal results on seminal analysis
• Two patients had low sperm density but normal semen volume and motility
• One patient had pathologic semen analysis results

All 18 patients had experienced prolonged unilateral testicular torsion before puberty and had undergone surgical untwisting with replacement of the nonviable testis in the scrotum. Fourteen of the patients had an absent testis on the affected side, and four had severe atrophy (< 1 mL). The contralateral side appeared normal or hypertrophic. Autosensitization due to sperm autoantibodies was not observed in these patients.

Given that time is of the essence in treating testicular torsion, parents must be aware of the possibility of testicular torsion when their children report testis pain. Prepubertal males should be encouraged to report any episodes of testis pain to parents or caregivers. Prepubertal males with acute testicular torsion may be at higher risk for orchiectomy than postpubertal males with this condition.[29]   

The typical presenting symptom of pediatric testicular torsion is severe scrotal pain of acute onset, commonly in association with scrotal swelling and erythema. Nausea and vomiting are common, as is local scrotal redness. Although most patients have severe pain with a rapid onset, occasional patients present with a history of pain lasting many hours or even days.

Upon examination, the classic findings of testicular torsion include an exquisitely tender, high-riding testis with an abnormal (transverse) orientation. Scrotal swelling and edema are common.

The cremasteric reflex is generally absent in cases of testicular torsion. In one series, the absence of cremasteric reflex was 100% sensitive for testicular torsion but only 66% specific (because many boys have an absent or decreased cremasteric reflex at baseline).[30, 31] An intact cremasteric reflex in the setting of torsion has been reported; thus, the presence of the reflex should not be used to rule out torsion in a patient whose presentation is otherwise suggestive of torsion.[31]

Intermittent torsion that persists with recurrent attacks of pain requires a careful examination to reveal subtle signs, such as excess testicular mobility and transverse testicular orientation. An elective scrotal exploration may be planned to look for a bell-clapper deformity and to avoid a dead testicle.

Although contemporary imaging techniques will correctly reveal testicular torsion in most cases, pediatric urologists and surgeons have been hesitant to rely too heavily on these diagnostic tests. Concerns over false-negative findings and the lengthy wait necessary to complete studies at some centers (and the lack of availability of radiology services of any kind at certain hours) have led many surgeons to rely on the clinical history and examination to guide the decision for surgery in most cases.

According to this philosophy, a negative finding on surgical exploration is indeed a better outcome than a necrotic testis due to a missed diagnosis. Such practices are reinforced by medicolegal concerns, particularly given the well-documented incidence of false-negative imaging results.[35, 36] Thus, at many centers, imaging studies are used primarily when the diagnosis is uncertain but the index of suspicion for testicular torsion is low.[37]

Testicular torsion is one of the more common diagnoses cited in lawsuits related to pediatric patients. A review of 53 cases between 1985 and 2015 found that emergency department physicians were the specialists most likely to be sued in this context and were more likely to receive an unfavorable verdict than urologists were.[38]

Laboratory studies may not be needed on a routine basis; however, a urinalysis may be helpful for ruling out an infectious process involving the lower urinary tract.

The most widely used imaging modality for evaluation of testicular torsion is ultrasonography (US) with Doppler scanning for blood flow. An absent Doppler signal in the testicular parenchyma is diagnostic of testicular torsion. Initial parenchymal echogenicity is decreased but may increase once infarction has ensued.

Like any other US modality, however, Doppler scanning is highly operator-dependent. Important factors to consider include assessing the presence or absence of blood flow in the central parts of the testis, taking into account the Doppler signals only from the centripetal branches of the testicular artery, minimizing motion artifact, and carefully comparing findings with the contralateral testis to make a confident decision.[35]

A markedly enlarged, echogenic, and avascular or hypovascular epididymis is an ancillary US sign in testicular torsion. A hypervascular enlarged epididymis can occur in 5% of cases and should not be dismissed as epididymitis.[39] In old torsion, the testis size is small, appearing echo-poor, with a prominent, enlarged epididymis. In cases of intermittent and early testicular torsion, false-negative findings can be expected.

US can be used to differentiate extratesticular pathology (eg, hydrocele, abscess, wall edema, and hematoma) from testicular etiologies (eg, tumor and torsion). It is often helpful in diagnosing epididymo-orchitis, characterized by increased blood flow to the testis and epididymis. In case of a torsed testicular appendage, an extratesticular hyperechogenic nodule can be identified between the head of the epididymis and the upper pole of the testis.[33]

Overall, Doppler US has been reported to yield a sensitivity of 88% and specificity of 90% for identifying testicular torsion. However, the sensitivity and specificity of this modality widely varies among institutions, depending on factors ranging from equipment to operator and radiologist experience. False-positive findings can be particularly troublesome in infants because of difficult flow detection in prepubescent testes.[40, 41]

US with a high-resolution probe (at least a 7.5-MHz transducer) has been employed to detect testicular torsion. This study is used to examine the cord in its entirety, from the inguinal canal downward, to detect a spiral twist (whirlpool sign[42] ), yielding a sensitivity of 97.3% and a specificity of 99% in confirming torsion.

High-resolution US has been reported to be superior to Doppler US alone. Again, the concern is that the findings are operator-dependent. This study is widely used in tertiary care centers but may not be available in many community or rural settings.[43]

Radioisotope scanning has been reported to be highly accurate for diagnosis of testicular torsion. The ischemic area is seen as a photopenic zone in testicular ischemia. In cases of inflammation and infection, increased uptake is seen.

Unfortunately, this modality is not widely available, and even centers with functioning nuclear medicine capabilities may not have these available at all hours. For this reason, US is more widely employed in the United States in most settings. Radioisotope scanning involves a low dose of radiation (2 mSv).[44]

Urinalysis may help to suggest an infectious etiology of scrotal pain when positive for pyuria and bacteriuria; however, urinalysis should not be allowed to delay treatment in cases where acute testicular torsion is suspected.

Some authors have explored the use of near-infrared spectroscopy (NIRS) to study and compare the tissue oxygen saturation index on the right and left spermatic cords and thereby identify testicular torsion.[45, 46]  In a prospective comparative study that included 121 males younger than 18 years who had acute scrotum for longer than 1 month, Schlomer et al found that whereas NIRS was of limited value for diagnosing torsion in the study group as a whole, it did discriminate well between torsion and nontorsion in Tanner 3-5 patients who did not have scrotal edema or who had had pain for 12 hours or less.[47]

Initial experience with scrotoscopy suggested that this minimally invasive modality was able to diagnose testicular torsion; however, given that such an approach requires anesthesia and scrotal incision, it might not be a viable diagnostic tool except in patients with a very high index of suspicion for whom scrotal exploration under anesthesia is already indicated.[48]  Subsequent studies suggested that this modality could be safe and effective not only for diagnosis but also for treatment.[49, 50]

Testicular torsion is a surgical emergency, and all efforts should be aimed at bringing the patient to the operating room as quickly as possible within the limits of surgical and anesthetic safety. Outcomes directly depend on the duration of ischemia; thus, time is of the essence.[3] Time wasted attempting to arrange for imaging studies, laboratory testing, or other diagnostic procedures results in lost testicular tissue.

Ongoing controversy surrounds the issue of exploration versus observation for perinatal torsion. This condition is uncommon enough that few centers see enough cases to merit any prospective studies, and medicolegal issues likely drive much of the decision-making in this area.[51, 52]

Various experimental studies in animal models have investigated ways of minimizing the testicular injury associated with ischemia-reperfusion injury. Agents as varied as superoxide dismutase, catalase, calcium-channel blockers, oxypurinol, and allopurinol have been used. Other agents used include melatonin,[53] zinc aspartate,[54] and dehydroepiandrosterone.[55] Unfortunately, none of these models has yet generated adequate evidence to justify trials in humans.

In some cases of testicular torsion, manually untwisting the spermatic cord may allow reestablishment of vascular flow. The technique involves manipulating the involved testis so that the anterior surface rotates from medial to lateral. This is termed the open book method because the motion resembles opening the cover of a book (for a right testis).

When successful, this maneuver almost immediately relieves pain in most patients. Manual detorsion is best performed with the intention of buying time until the surgical team is ready, rather than with the intention of  avoiding a surgical procedure altogether.[56]

Reports of this procedure have suggested that it is highly effective, in that it allows the acute emergency to be converted into an elective surgical procedure, with a quoted salvage rate of 100%.[7] Cornel et al reported that no testicular atrophy was detected after performing a manual detorsion.[57]  Siu Uribe et al found that manual detorsion and elective orchidopexy appeared to be efficient and reliable in children with testicular torsion.[58]  

In actuality, manual detorsion is difficult and is not commonly used. Application of this maneuver in an emergency department setting in a child with a swollen painful scrotum can be difficult or impossible without anesthesia. Furthermore, the testis may not be fully detorsed or may retorse shortly after the patient leaves the hospital. In addition, knowing which way the testis is torsed a priori is impossible; thus, attempting detorsion may simply worsen the degree of torsion.

The goals of surgical exploration are as follows:

• Confirmation of the diagnosis of torsion
• Detorsion of the involved testis
• Assessment of the viability of the involved testis
• Removal of the involved testis (if it is nonviable) or fixation (if it is viable)
• Fixation of the contralateral testis, when appropriate

Because of the concern regarding the possibility of asynchronous testicular torsion, contralateral exploration and fixation is widely performed.[59, 60, 61]

The argument against surgical exploration includes the low probability of salvage in the setting of old torsion (>24-48 hours). However, proponents of surgery argue that in view of the medicolegal implications, exploration must be performed to prove the diagnosis, to salvage the testis (if possible), and to perform a concurrent contralateral orchidopexy. Indeed, surgeons rarely experience medicolegal consequences for a negative exploration finding in the setting of acute scrotum, whereas lawsuits for failure to explore are routine.[62]

Indications for surgery

In the neonate with acute scrotum at birth or a few days afterward, surgical recommendations are controversial. Although most authorities recommend exploration of the ipsilateral side and fixation of the contralateral testis, some have suggested that observation is acceptable because of the negligible salvage rate of the ischemic testis and the low incidence of contralateral torsion. The risk of anesthesia in children younger than 1 year may also factor into decision-making process.

In the prepubertal boy with acute scrotum, exploration with salvage of the ipsilateral testis is recommended, if possible. If testicular torsion is confirmed, contralateral orchiopexy is recommended. Differential diagnoses to consider include torsed appendix epididymis ("blue-dot" sign) and epididymitis. If a clear-cut blue-dot sign is identified and confirmed with Doppler ultrasonography (US), a nonsurgical approach is justified.

In the adolescent with acute scrotum, exploration with salvage of the ipsilateral testis is recommended, if possible. If torsion is confirmed, contralateral orchiopexy is recommended. If the testis has not been salvaged, ipsilateral orchiectomy is usually performed.

Operative details

Exploration can be performed via a paramedian scrotal incision, a transverse incision, or a single midline scrotal incision. Some surgeons prefer to explore the acute scrotum through an inguinal incision, theorizing that this approach offers better control of the high spermatic cord if the exploration reveals an unexpected diagnosis (eg, testis tumor).

It may be difficult to determine intraoperatively whether a testis of marginal viability should be retained or excised. Although retaining a marginal testis may appear to carry no negative consequences, long-term concerns about the immunologic consequences of the infarcted testis have been raised. Testicular ischemia disrupts the blood-testis barrier, which may result in autoimmunization against spermatozoa and formation of antisperm antibodies; this may affect sperm produced by both testes.

However, both spermatogenesis and the blood-testis barrier are established after age 10 years; thus, some surgeons always retain the doubtful testis in children younger than 10 years.[5]

Arda et al recommended that the testis be incised at exploration to look for bleeding as a measure of viability. Bleeding was graded as follows[63] :

• Grade I - Immediate bleeding
• Grade II - Bleeding after 10 minutes
• Grade III - No bleeding after 10 minutes

Excision of the testis was recommended for grade III.

Once the testis has been detorsed and the decision is made to preserve it, the tunica vaginalis is everted, as in a Jaboulay procedure; two or three sutures are passed through the dartos and tunica albuginea of the testicle. Some surgeons avoid placing sutures directly into the tunica albuginea, out of concern about possible disruption of the blood-testis barrier; instead, they place the sutures into the visceral tunica vaginalis of the mesorchium.[64]

Kuntze et al reported that absorbable sutures predispose to recurrent torsion after orchiopexy; thus, nonabsorbable sutures are recommended for securing the testis.[65]

Window orchidopexy has been performed to ensure better fixation of the testis and thus avoid recurrent torsion, on the principle that creating a window in the tunica vaginalis makes a broad area of dense adhesion during healing, which results in better apposition.[66] Sutureless fixation in a dartos pouch has been reported for neonatal orchiopexy[67] in performing a contralateral exploration.

As many as half of patients with testicular torsion who undergo salvage surgery may develop testicular atrophy, even when the testis was intraoperatively assessed as viable.[68] Pain lasting longer than 12-24 hours and heterogeneous echogenicity on US are predictive.[68, 69]  

Although long-term observation to monitor for testicular atrophy would be helpful in patients with testicular torsion, in actuality, many of these patients (particularly the adolescents) do not return for follow-up. In patients who do return, annual scrotal US during the 2-3 years after surgery can be used to document testicular volume and growth.

Recurrent torsion following an orchiopexy is possible (though rare) and may occur several years after the initial fixation of the testis. Thus, patients and parents should be forewarned about this risk and should promptly seek medical care if testicular pain occurs, even after an orchiopexy has been performed.[34]

Analgesic and antianxiety medications are valuable adjuncts in the treatment of testicular torsion. Pain control is essential to quality patient care. It ensures patient comfort, promotes pulmonary toilet, and enables physical therapy regimens. Antiemetics can be used to counter the nausea and vomiting that may accompany testicular torsion.

Class Summary

Most analgesics have sedating properties, which are beneficial for patients who have sustained painful trauma.

Morphine sulfate (Duramorph, Astramorph, MS Contin)

Morphine is the drug of choice for narcotic analgesia due to reliable and predictable effects, safety profile, and ease of reversibility with naloxone.

Various IV doses are used; the dose is commonly titrated until the desired effect is obtained.

Class Summary

These agents are used to prevent nausea and vomiting.

Prochlorperazine (Compro)

Prochlorperazine may relieve nausea and vomiting by blocking postsynaptic mesolimbic dopamine receptors through its anticholinergic effects and depressing the reticular activating system. In addition to its antiemetic effects, it has the advantage of augmenting hypoxic ventilatory response, acting as a respiratory stimulant at high altitude.

Metoclopramide (Reglan, Metozolv)

Metoclopramide blocks dopamine receptors in the chemoreceptor trigger zone of the central nervous system.

Ondansetron (Zofran)

Odansetron is a selective 5-HT3-receptor antagonist that blocks serotonin both peripherally and centrally. It prevents nausea and vomiting, including that associated with emetogenic cancer chemotherapy (eg, high-dose cisplatin), and complete body radiotherapy.

Class Summary

These agents are used to reduce anxiety.

Diazepam (Diastat, Valium)

Diazepa modulates the postsynaptic effects of gamma-aminobutric acid–A (GABA-A) transmission, resulting in an increase in presynaptic inhibition. It appears to act on part of the limbic system, the thalamus, and hypothalamus, to induce a calming effect. It also has been found to be an effective adjunct for the relief of skeletal muscle spasm caused by upper motor neuron disorders.

Diazepam rapidly distributes to other body fat stores. Twenty minutes after initial IV infusion, the serum concentration drops to 20% of maximum plasma concentration (Cmax).

Individualize dosage and increase cautiously to avoid adverse effects