Diagnosis and Management of Pediatric Varicocele: A Modern Update for the Practicing Pediatrician

Physical examination is a central component of diagnosis as most adolescent varicoceles are detected during routine medical examination for school or sports [7]. In contrast, many adult varicoceles are identified by physical examination for infertility evaluation [7]. In pediatric patients with suspected varicoceles, a thorough history and physical exam should be performed, including scrotal examination in the standing and supine position in a warm environment [8]. The scrotum should be palpated, and the patient should be asked to perform a Valsalva maneuver [9]. Varicoceles are typically palpated as a plexus of veins with a consistency of a “bag of worms,” which commonly decompresses when supine [10]. Important components of the physical examination include assessment of varicocele Grade, testicular volume, and testicular consistency [9]. A softer consistency of the involved testis will be noted in a small percentage of boys and is typically associated with decreased volume. Abnormal consistency is a subjective finding, and it has not been thoroughly studied [10]. Most clinical practice guidelines agree that the diagnosis of a varicocele in this population is primarily based on physical examination [11]. According to the American Urological Association (AUA) and the American Society of Reproductive Medicine (ASRM), if the physical examination is inconclusive, a scrotal ultrasound may be performed [12].

Varicoceles are graded using the Dubin and Amelar system: Grade 0, subclinical varicocele (not detectable on clinical examination but identified on scrotal ultrasound [US] or venography); Grade I, small varicocele (palpated only during the Valsalva maneuver); Grade II, moderate size (readily palpable without the Valsalva maneuver but not readily visible without Valsalva); and Grade III, large size (readily visualized without Valsalva) [13]. Examination for the purpose of grading should be performed in the standing position. Grade II and III varicoceles are generally identifiable on physical exam and are commonly referred to urologists [8]. In adolescents, a direct correlation between varicocele Grade and semen parameters has not been observed [14]. Therefore, varicocele Grade alone has been argued to not be an indication for surgical repair [14]. In addition, varicocele Grade has not been proven to be a reliable indicator of future asymmetry, which is associated with abnormally low total motile sperm counts (TMSC) [15].

The European Society of Paediatric Urology (ESPU) recommends evaluating the size of both testicles by orchidometer or ultrasound, and a testis that is smaller by 2 ml or 20% compared to the other testis is considered hypoplastic [11]. The most commonly utilized method to calculate individual testicular volume is the Lambert formula, where volume = length (L) × width (W) × height (H) × 0.71. Total testicular volume (TTV) correlates with total sperm count in adolescents [8], although one study has suggested otherwise [16]. Testicular ultrasound has been found to be more sensitive than orchidometer in detecting volume differentials between testes [17]. Of note, testis ultrasound measurements may be imprecise due to sonographer variability and variable placement of cursors for determining length, width, and height [14]. Thus, many believe that the decision to undergo surgery should be based on several measures rather than one [14]. No matter what method is used to determine testicular volume, consistency is key to obtaining a reliable measure of testicular growth over time [14]. Therefore, annual ultrasound calculation of testicular volume to evaluate the adolescent with varicocele is recommended [17].

Testicular volumes should be compared to evaluate for asymmetry. The two commonly used formulas to compare volume asymmetry are the Testicular Atrophy Index (TAI) and Testicular Volume Differential (TVD, or TVDiff). While TAI represents the size discrepancy of one testicle relative to the other, TVD frames the discrepancy relative to the total volume of the testicles combined. TAI may be calculated using the formula [ (volume of unaffected testis—volume of affected testis) / volume of unaffected testis] × 100%. Testicular volume differential is defined as TVD = [ (volume of unaffected– volume of affected testis) / total testicular volume] × 100%. It is important to distinguish that “TVD” is sometimes misapplied to abbreviate “testicular volume discrepancy” or “testicular volume difference”, which are in fact equal to TAI as they compare one testicular size to the other, rather than to TTV. The values TAI and TVD can be converted between one and the other, with a TAI of 20% corresponding to a TVD of approximately 11% [18].

In a study on 17 to 19 year-olds with grade 2 and 3 varicoceles, poorer semen quality correlated with greater asymmetry. Sonographically derived testicular volume differential (TVD) greater than 10% have been shown to correlate with a significantly decreased sperm concentration and total motile sperm count [19]. Similarly, in a study of 12 to 17 year-olds with idiopathic varicocele, those with TAI of 20% or more were significantly more likely to have sperm concentration falling below normal values [20].

The European Association of Urology (EAU) recommends confirmation of varicocele by color duplex Doppler analysis after physical examination [11]. A 3.0 mm minimum vein diameter with retrograde blood flow has been accepted as the criteria for varicocele. Deferential vein reflux plays little role in the development of a varicocele or recurrence [15, 21]. Sonography should therefore focus primarily on large vein reflux rather than distal collaterals such as the deferential vein. Peak retrograde flow (PRF) in prominent vein(s) draining a testis affected by varicocele has been shown to be a clinically useful metric. The sonographic technique for PRF was first described in 2009. Patients should be supine and relaxed, and the largest diameter vein within the pampiniform plexus identified. Then, the patient should be instructed to perform Valsalva, and PRF should be measured within that vein on duplex Doppler ultrasound [22]. In a study on 17 to 19 year-olds with grade 2 and 3 varicoceles, poorer semen quality correlated with higher PRF. Boys with ≥ 20% testis asymmetry (TAI) in conjunction with a Doppler-detected PRF of 38 cm/s or greater will have persistent or worsening future asymmetry [22, 23].

Semen analysis (SA) may be the most accurate predictor of future fertility, but its role in the evaluation of varicoceles in adolescents is unclear [9]. SA is not commonly used by pediatric urologists in pediatric patients with varicoceles [8]. In a 2016 survey of Society for Pediatric Urology (SPU) members, only 13.1% routinely incorporate SA in their practice, with 48% having discomfort asking for one [24]. Repeated SAs are necessary in the management of these patients as nearly half of patients with an initially poor total motile sperm count (TMSC) demonstrated normal counts on the second SA, although a subpopulation of high-risk patients had persistently poor TMSC [25]. A SA has been considered preferable to relying on a moderate hormonal correlate [26].

There is currently no consensus on the utility of hormonal evaluation in this population, although it is known to be beneficial in the adult population [8]. Inhibin B has been shown to be reduced in adolescents with untreated varicocele, and reduced levels are associated with decreased testicular volume [27]. In the adult population, varicocele presence has been associated with higher serum levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) with lower inhibin B levels [28], although a different study found that inhibin B levels decreased but FSH, LH, and testosterone were normal [27].

The initial step in adolescent varicocele management should include a detailed history and physical examination. Important elements of the history include history of cryptorchidism, scrotal surgery, history of gonadotoxic therapy (e.g., chemotherapy for leukemia), and family history of testis cancer. Physical examination should be performed in the standing position for the purpose of grading. Assessment with orchidometer volume measurement and/or ultrasound volume and PRF assessment should follow. It is critical to record baseline values and TAI for serial comparisons. SA may be offered for patients who have reached Tanner V. However, in patients who are uncomfortable or unwilling to provide semen for sampling, it is acceptable to defer this.

In most cases, an asymptomatic adolescent varicocele may be managed conservatively with regular follow-up for re-assessment. For patients who have not yet reached Tanner V, this approach should be considered as the first line. It is always important to educate patients on the rationale behind expectant management.

Initial volume analysis may reveal size atrophy of the affected testis. A TAI of ≥ 20% or volume difference of 2 mL has historically been an indication for surgical intervention, but more recent studies have challenged this guideline [29]. Rather, patients with a TAI of at least 20% should have a repeat ultrasound in one year to assess for resolution or persistence. Patients should be reassured that testicular size discrepancy is common and often self-resolving, a phenomenon commonly referred to as “catch-up growth.” Glick et al. found that in patients 11–18 years old with at least 15% TVD and asymptomatic varicocele, 80% of patients with non-operative management will exhibit catch-up growth at repeat ultrasound one year later [30]. These findings were consistent with Kolon et al. who showed a normalization of TVD in 85% of patients followed for 2 years [31]. A 2018 study found that 1 in 5 boys aged 11–16 years with ultrasound confirmed absence of varicocele had a TAI of at least 20%, and the average TAI was 17% [32]. In 2023, Lourdaux et al. also studied TAI in boys with confirmed varicocele absence, finding that 10% of them have a TAI of at least 20% [33]. Nearly 70% of this size discrepancy was resolved at some point in the future. A TAI of 10–20% should be followed regularly, but persistence of this size discrepancy is not an indication for intervention as it can be seen in healthy patients [34]. Lastly, a TAI of < 10% in the absence of other findings on PRF or SA does not warrant follow-up or repeat measurement [34]. In light of these studies, TAI should be serially measured in the absence of other factors regarding varicocele intervention. Follow-up should occur annually and include repeat of volume measurements at the very least [35].

In addition to testis asymmetry, low TTV in the setting of unilateral varicocele has been touted to likely have meaningful prognostic value. In a retrospective study of over three hundred Tanner V boys with unilateral varicocele, Fang et al. reported those with TTV < 29.5 cc demonstrated statistically significantly lower TMSC than those boys with larger TTV [29].

Though pre-pubertal varicocele is rare, conservative management can be similarly offered for these younger patients. Pre-pubertal presentation of varicocele has been shown not to affect outcomes, with similar rates of long-term testicular hypotrophy and need for surgical intervention in matched pre- and post-pubertal individuals with varicocele [36].

Semen analysis is a useful adjunct that may be offered to patients undergoing conservative management, though it can be deferred in patients who meet the previously described criteria. While this tool is considered a direct assessment of testicular function and fertility, it can be used as confirmation once conservative evaluation shows persistent TAI, low TTV, or elevated PRF.

Symptomatic painful varicoceles should always be offered referral, as this is a correctable issue with surgical intervention. Those with varicocele-related pain typically report dull, throbbing, or aching pain in the region of the scrotum, testicle, or groin [37]. This is exacerbated with prolonged standing and activity. Less common but still attributable pain may be described as sharp, stabbing, or acute.

Appearance and size are relative indications for correction and should be evaluated on a case-by-case basis. Large varicoceles that cause patients distress out of fear that partners will notice or find their varicocele off-putting is a consideration for intervention. Similarly, large varicoceles may be bothersome to patients who are particularly physically active.

The presence of bilateral varicocele warrants referral as these individuals may be immediate candidates for surgical repair. Because both testes may be affected, comparison of testicular volumes is not valid, making the varicocele difficult to follow and trend.

In Tanner V individuals, a persistent TAI ≥ 20% (TVD of 11% [18]) on two separate measurements taken 12 months apart should be considered for further evaluation. Failed catch-up growth may be a sign of persistent, non-resolving, varicocele-induced testicular atrophy that will continue to have a detriment to the affected testis. These individuals could be offered semen analysis for potential surgical repair or an opportunity to proceed directly to surgical repair.

In addition to persistent TAI, TTV insufficiency is an indication for semen analysis. A recent study including only Tanner V boys found that TTV < 29.5 cc was associated with significantly lower TMSC [29]. Assessment of TTV should be compared on at least 2 separate occasions separated by 12 months [14].

Peak retrograde flow measured by ultrasound represents an objective tool for varicocele evaluation and management pathway. This may be of interest especially when providers encounter patients unwilling to provide a semen sample on initial consultation. It has been shown that PRF > 38 cm/s is associated with increased sperm DNA fragmentation [38]. Patients for whom PRF falls between 30–38 cm/s should have yearly follow-up, with sonography repeated at each visit [34].

At any point in evaluation, a simultaneous TAI of at least 20% and PRF > 38 cm/s warrants immediate urologic referral. This combination of findings has been labeled the “20/38 harbinger” and individuals with this set of findings rarely exhibit catch-up growth [39]. Rather, these patients have further progression of the already existing testicular asymmetry [38].

In Tanner V patients with any of the aforementioned parameters, SA should be offered as an accurate and confirmatory assessment of current testicular and sperm function. Discussion of SA may come with resistance by the patient, and an understandable level of discomfort on the physician’s behalf. As such, this topic should be approached with emphasis on its objective diagnostic utility. Varicocelectomy has been shown to improve TMSC [40]. Furthermore, TMSC may be the most important aspect on SA to predict fertility [41]. The WHO considers 20 million TMSC as the lower fifth percentile, and values falling below this threshold are regarded as abnormal. Once SA is obtained, a repeat analysis should be performed in 3–6 months to confirm [14]. Although abnormal SA is an indication for referral and potential surgery, the need for surgical intervention is not immediate. It ought to be highlighted that improvement in SA and TMSC is seen regardless of when varicocele repair is performed, whether during the adolescent period or in young adulthood [42]. Acknowledging this, in a retrospective study examining pre- and post- microsurgical inguinal varicocelectomy in patients ≤ 20 years, 21–30 years, and ≥ 30 years, the greatest upgrade in TMSC was observed in patients < 20 years with Grade 3 varicoceles compared to other varicoceles Grades and older patients [42].