Torsion of the Testicle
DIANA K. BOWEN
ROBERT E. BRANNIGAN
Testicular torsion is a true urologic emergency, requiring a provider to arrive at a timely diagnosis with a fast transition to surgical intervention in order to prevent testicular injury or necrosis. It is a clinical problem in both pediatric and adult urology, with a recent population-based study giving a yearly incidence of 3.8 in 100,000 for males younger than 18 years old (1). This predicts that 1 in 1,500 males will undergo surgery for torsion by that age, compared to older estimates of 1 in 4,000 for men younger than 25 years old (2). Despite wide recognition of this condition, 30% to 41% all cases will have a nonviable testis at the time of surgery and undergo orchiectomy (1,3,4). Ramifications of delayed treatment include atrophy, possible testicular loss, decreased endocrine function, and reduced sperm count and future fertility. If torsion is suspected, emergent scrotal exploration should be undertaken given that even partial necrosis has been seen to occur as early as 4 hours (5,6). The injury to the testis occurs from ischemia as well as reperfusion from reactive oxygen species (7).
There is a bimodal incidence of torsion with peaks at 1 month of age and a second at 12 years, thought to reflect the clinical distinction between extravaginal torsion in the perinatal period and intravaginal torsion in older children. In this way, the anatomy of a testicular torsion is correlated with the expected age of the patient—the point of difference is whether the torsion occurs above or below the reflection of the tunica vaginalis (Fig. 62.1). Intravaginal torsion results from a twist in the spermatic cord within and not involving the tunica vaginalis. Also known as a “bell clapper deformity,”, it is hypothesized to be due to an abnormally high insertion of the tunical attachments to the testis and epididymis so that there is incomplete attachment (Fig. 62.2). Intravaginal torsion is seen in the older age group primarily, although can be seen rarely in the perinatal period. Surprisingly, autopsy studies report the incidence of a bell clapper deformity to be as high as 13% in normal subjects, thus unlikely to account solely for the cause of torsion (8). Individuals with undescended testes are also presumed to be at a higher risk although this is from
only a handful of accounts and has not changed the current recommendations that infants undergo orchidopexy at the age of 6 to 12 months. At this time, no other predisposing factors can be definitively linked with testicular torsion.
only a handful of accounts and has not changed the current recommendations that infants undergo orchidopexy at the age of 6 to 12 months. At this time, no other predisposing factors can be definitively linked with testicular torsion.
Extravaginal torsion, however, is a twist of the testis, cord, and tunica vaginalis due to deficient attachment of the gubernaculum to the dartos, and thus, it is much more likely to occur in the perinatal period. Possible predisposing factors include a large birth weight and difficult delivery, but these remain only postulations (9,10). Extravaginal torsion encompasses perinatal cases, of which an estimated 72% occur in utero and present as a “vanishing” nonpalpable testis at birth (11). The remaining important minority of cases present variably depending on the timing of the event and may be insidious. Suggestive findings at birth include an indurated, erythematous scrotum, a dark discoloration with or without edema, and/or a coexisting hydrocele. Often, the infant will be asymptomatic.
DIAGNOSIS
Clinical Presentation
The presenting signs and symptoms vary significantly by the type of torsion and therefore often the age of the patient; however, a sudden onset of pain and/or an abnormal hemiscrotum with a high-riding testis should always be concerning for testicular torsion.
Intravaginal Torsion
The description of sudden-onset unilateral testicular pain is a classic history for intravaginal testicular torsion. Nausea and vomiting are often present as well. On physical exam, the hemiscrotum can be swollen and edematous, and there may be evidence of a high-riding testis or horizontal lie. Lack of a cremasteric reflex, defined in one study as less than 0.5 cm elevation, has been highly associated with torsion, with positive predictive values of 43% to 83% and negative predictive values of 96% to 98% (12). However, the presence of a reflex does not rule out torsion (13). There is no single feature predictive of torsion, but a combination of two or three of these should be considered highly predictive (12).
Intermittent torsion is often a difficult clinical problem, as there may be no evidence at the time of evaluation of torsion. Patients may have recurrent bouts of pain that resolve rapidly and can occur with any time pattern. Making diagnosis even more difficult is that often ultrasound does not show evidence of reduced blood flow and typical physical exam findings, such as the cremasteric reflex, may not be present, even during a bout of pain (14). Bilateral elective orchidopexy can be considered based on a high degree of clinical suspicion.
Torsion of Appendage
Torsion of a testicular appendage is often characterized by a gradual onset and few systemic symptoms. Although the four testicular appendages that have been identified—the appendix testis (hydatid of Morgagni), the appendix epididymis, the paradidymis, and the vas aberrans of Haller—are all susceptible to torsion, the most commonly involved is the appendix testis. In the pediatric age group, appendiceal torsion is nearly as common as testicular torsion and accounts for 20% to 40% of acute scrotum cases (15). Early in the course of torsion of the appendix testis, physical examination may reveal a tender mass located at the upper pole of the testicle, sometimes adherent to the overlying skin. The testicle will usually have a normal orientation and the cremasteric reflex intact (13). There may be a tender mass located superiorly on physical exam, but torsion of the testicle and appendage can become clinically indistinguishable with time. Imaging with Doppler ultrasound frequently shows a hyperechoic mass at the upper pole of a normal-appearing testicle. Therapy consists of bedrest, scrotal elevation, and nonsteroidal anti-inflammatory agents as needed. Symptoms should begin to resolve within 1 to 2 weeks as the infarcted appendage is gradually resorbed. If testicular torsion cannot be ruled out with certainty, urgent surgical exploration is needed.
Extravaginal Torsion
In prenatal torsion, the first newborn exam will usually reveal a firm scrotum that is indurated and either erythematous or with a darker hue than the contralateral side (Fig. 62.3). Often, this is an isolated finding and the infant will not be systemically symptomatic. This is in opposition to postnatal torsion, which is new in onset after birth, and more likely to be accompanied by irritability and crying. The decision to operate in the perinatal period is controversial depending on the timing of findings and age of the patient. There is a conceptual difference between prenatal and postnatal torsion stemming from the fact that prenatal torsion is rarely salvageable and thus exposes an infant often within the first month of life to the risks of general anesthesia and surgical complications. Kaye et al. (10) advocates that infants found to have a unilateral prenatal torsion be treated with orchiectomy and contralateral orchidopexy after 1 month of age, as the risk of complications is greatest before this time period. On the other hand, bilateral prenatal torsion (or any bilateral torsion for that matter), and unilateral postnatal torsions should be taken for immediate exploration and potential orchidopexy. The argument against delaying exploration in prenatal cases is both the possibility of salvage, albeit low, as well as the possible occurrence of bilateral synchronous or asynchronous testis torsion, which may not be as rare as previously thought (16).
Differential Diagnosis
The differential diagnosis for testicular torsion includes infection or inflammation (epididymo-orchitis), scrotal edema, hernia or hydrocele, torsion of the appendix testis, or trauma. It is especially important to be aware that torsion can occur in the setting of a trauma, potentially clouding the diagnosis. A more gradual onset of pain and urinary symptoms or a history of urinary tract infections are suggestive of epididymo-orchitis, which is commonly confused with torsion. Finally, torsion of a testicular appendage can present similar to testicular torsion, but the treatment for the former is purely conservative thus diagnosis is paramount. The pathognomic finding of an appendage torsion is the blue dot sign, which is the appearance of a small 1- to 3-mm palpable “dot” that has a bluish hue beneath the characteristically thin scrotal skin.
Diagnostic Modalities
Laboratory Testing
Basic laboratory testing includes a urinalysis to investigate for infection or hematuria. If an infection is considered, a urine culture, complete blood count (CBC), and serum chemistry may be indicated.
Ultrasound
In the mid-1990s, color Doppler ultrasound (CDUS) was introduced as an important tool in the diagnostic workup of torsion, and its use has steadily increased. Lack of intratesticular blood flow is the characteristic finding (Fig. 62.4). However, reports of an unacceptably high rate of falsenegative exams remain, with an overall sensitivity ranging from 69% to 95% (17,18,19,20,21). This is likely due to the period of time before arterial blood flow ceases due to venous congestion and worsening edema. Some studies have suggested certain findings can increase the sensitivity for torsion such as noting a reversal of diastolic flow in the Doppler waveform or heterogeneous echotexture that may be predictive of eventual testicular loss (10,22). In addition, with high-resolution ultrasound (HRUS) that uses a higher frequency (10 to 20 mHz), visualization of the spermatic cord has been suggested as an adjunct. Kalfa (19) suggested the appearance of a cord twist on HRUS that looked like a whirlpool or “snail-shaped” mass was suggestive of torsion, although this is not 100% and more robust studies are needed to corroborate this finding (Fig. 62.5). Consideration should thus be given to perform the scrotal US exam up to the level of the internal ring for a more thorough evaluation of not just the testis but also the spermatic cord.