A varicocele is a pathological dilation and congestion of the pampiniform venous plexus in the spermatic cord, mainly because of the venous valve insufficiency or congenital absence of valves [1]. Epidemiological data suggest that varicocele affects about 15% of adult males globally, but this prevalence rises significantly to about 40% in men who present with primary infertility, making it the most common treatable cause of male infertility [2]. Anatomically, the disease is left-sided most of the time. This is due to the distinct vascular anatomy of the left spermatic vein, which drains into the left renal vein at an almost right angle. This anatomical arrangement leads to a higher hydrostatic column of blood with increased pressure predisposing the left pampiniform plexus to venous reflux and subsequent dilation [1, 2].

The pathophysiology of the connection between varicocele and impaired testicular function is multifactorial. The stasis of venous blood disrupts the counter-current heat exchange mechanism of the spermatic cord, leading to increased intrascrotal temperatures. This thermal stress, along with localized hypoxia and accumulation of toxic metabolites and reactive oxygen species (ROS), leads to substantial oxidative stress in the testicular microenvironment. These adverse conditions over time induce germ cell apoptosis, Leydig and Sertoli cell dysfunction, and collagen deposition in interstitial spaces, resulting in impaired spermatogenesis and parenchymal fibrosis [3,4].Traditional diagnostic assessment is heavily dependent on high resolution gray scale and color/spectral Doppler ultrasonography [3]. These standard modalities are very effective for visualizing dilated veins (generally >3 mm in diameter) and confirming retrograde blood flow during a Valsalva maneuver, but they have a major limitation in that they only assess macroscopic vascular anomalies. The sensitivity of standard ultrasound is not enough to detect the early microscopic microstructural damage to the testicular parenchyma before the gross, irreversible testicular atrophy. Shear Wave Elastography (SWE) is an advanced, adjunctive ultrasound technique to help bridge this diagnostic gap. SWE measures the stiffness of tissues using the application of acoustic radiation force impulses to induce transverse shear waves in the target tissue. The speed of propagation of these shear waves is directly proportional to the rigidity of the tissue. The softer, healthy testicular parenchyma slows the waves, whereas the stiffer, fibrotic tissue transmits them rapidly. SWE generates objective, reproducible and quantitative maps of tissue elasticity in kilopascals (kPa) or meters per second (m/s) [4,5].Therefore the objective of this study was to assess the stiffness of varicocele-affected testes using SWE and to correlate these elastographic findings with conventional parameters of semen analysis and clinical grades of varicocele.

Study Design and Setting: The present case control study was conducted in the Department of Radiodiagnosis, Bangalore Medical College and Research Institute, Bangalore from May 2023 to October 2024. All participants provided written informed consent . Study Participants: 100 adult males (n=50 cases and n=50 controls) were recruited. Inclusion Criteria (Cases): Patients of 18-45 years age diagnosed with varicocele. Inclusion criteria (Controls): Healthy age matched males with normal semen analysis and normal scrotal ultrasound. Exclusion Criteria: History of surgery, trauma, previous malignancy, testicular microlithiasis, hydrocele, scrotal masses or recent orchitis. Evaluation: Ultrasonography was done using high frequency linear probe (7-11 MHz) on Trivitron Sonorad V60. Varicocele grading was done using Sarteschi classification [6]. Testicular stiffness was measured by means of Shear Wave Elastography (5 measurements per testis mean in kPa/m/s). Statistical Analysis: Analyzed by appropriate Stastical software using Student’s t-test, Mann-Whitney U test, and Spearman’s rank correlation coefficient (p < 0.05 = significant).

The demographic characteristics revealed that mean age was 31.0 ± 7.83 years for cases and 31.1 ± 5.40 years for controls. The case group had an average BMI of 25.34 ± 1.49 kg/m2 which was a little higher than the control group 23.3 ± 3.90 kg/m2 .

Left-sided varicocele was predominant in 50 cases (92%, n=46). Grade II varicocele was the most common (72%) followed by grade IV (14%) and grade III (12%). There was no statistical difference in testicular volume between cases and controls (mean left volume 11.99 ± 1.06 cc in cases vs. 11.99 ± 1.13 cc in controls, p > 0.05).

In cases, testicular stiffness was statistically significantly increased on shear wave elastography. Mean left testicular stiffness in cases was 5.15 ± 0.67 kPa/m/s and in controls it was 3.06 ± 0.21 kPa/m/s (p < 0.001). Left testicular stiffness was significantly correlated with the varicocele grade, with the mean value increasing from 4.83 kPa/m/s in Grade II to 6.40 kPa/m/s in Grade IV (p < 0.001). Oligospermia was detected in 50% of patients. A highly significant inverse correlation was demonstrated between left testicular stiffness and sperm concentration (r = -0.81, p < 0.01).

Table 1: Demographic Characteristics

Table 2: Distribution Based on Varicocele Grade (Sarteschi Classification)

Table 3: Comparison of Testicular Volumes

Table 4: Correlation of Left Testicular Stiffness with Varicocele Grade

The management of varicocele depends on the accurate identification of patients whose fertility is actively compromised by varicocele. The aim of our study was to evaluate the usefulness of SWE in detecting microstructural damage of testicular parenchyma by measuring tissue stiffness and correlating these findings with semen quality and varicocele grading. Demographically, the high prevalence of left-sided varicoceles (92%) in our cohort is in complete agreement with established literature regarding the anatomical vulnerability of the left spermatic venous drainage system [1,2]. The case group also showed a slightly higher mean BMI (25.34 kg/m²) than the controls (23.3 kg/m²). This is in keeping with studies that propose that body habitus and intra-abdominal pressure mechanics may play a subtle contributory role in exacerbation or development of spermatic vein reflux [2]. One of the most interesting findings in our study was the difference between testicular volume and testicular stiffness. Routine grayscale ultrasound did not find a statistically significant difference in the total testicular volume between varicocele patients and healthy controls. Testicular atrophy (volume loss) is considered a late, often irreversible consequence of long-term varicocele. Because our cohort was mainly composed of early-to-moderate grade varicoceles, significant atrophy had not yet taken place. However, SWE was able to detect significant pathological changes missed by grayscale ultrasound. The mean left testicular stiffness was dramatically higher in cases (5.15 kPa/m/s) than in controls (3.06 kPa/m/s). This increased rigidity is the mechanical expression of the underlying pathophysiology, where chronic venous stasis leads to localised hypoxia, oxidative stress and subsequent collagen deposition and fibrosis within the delicate interstitial spaces of the testis [4,5]. Our results are in agreement with the findings of Turna et al. [7] and Ahmed et al. [8] and reinforce the hypothesis that parenchymal stiffness is a much more sensitive and earlier biomarker for structural deterioration than simple volume loss. In addition, our data showed a progressive positive correlation between varicocele severity (Sarteschi grade) and testicular stiffness. Stiffness increased from 4.83 to 6.40 kPa/m/s with a predictable step in clinical grade from II to IV. This finding indicates a dose-response relationship where more severe venous reflux is associated with more extensive cumulative fibrotic damage to the parenchyma. Our results are in good agreement with that of Ahmed et al. [8] who also reported positive correlation between varicocele grade and stiffness. However, note that some studies like Turna et al. [7] did not find such significant correlation. The discrepancy in the studies may be due to the different demographics of the cohort, the duration of the varicocele before evaluation or differences in the elastography equipment and operator technique. The last functional consequence of this structural stiffening was seen in the semen analysis. Oligospermia was present in 50% of our varicocele cohort. We observed a strong statistically significant inverse correlation (r = -0.81) between sperm concentration and left testicular stiffness. Simply put, the more rigid and fibrotic the testicle, the less ability to produce sperm in proportion. This finding has a tremendous clinical implication. This is in line with the findings of Abdelwahab et al. [9] who showed that SWE values are directly correlated with impaired spermatogenesis and may even predict the patients most likely to have a rebound in semen parameters after varicocelectomy. Clinically, semen analysis and grayscale ultrasound alone may delay surgical intervention until irreversible parenchymal damage has already occurred. The routine infertility workup including the SWE allows the clinicians to reveal increased testicular stiffness in an early disease stage. This objective metric can be an important screening tool to recommend proactive surgical management (varicocelectomy) to preserve fertility before profound oligospermia or irreversible testicular atrophy occurs.

Shear Wave Elastography (SWE) is a very useful, non-invasive diagnostic method for the evaluation of testicular parenchyma stiffness in patients with varicocele. The significant increase in stiffness is strongly correlated with the advanced severity of varicocele and decreased semen quality (oligospermia). SWE may serve as an important adjunctive biomarker to guide clinical management of varicocele-associated male infertility by detecting early structural deterioration prior to gross volume loss.

1. Fretz PC, Sandlow JI. Varicocele: current concepts in pathophysiology, diagnosis, and treatment. Urol Clin North Am. 2002;29(4):921-937.
2. Nagler HM, Grotas AB. Varicocele. In: Lipshultz LI, Howards SS, Niederberger CS, eds. Infertility in the male. 4th ed. New York: Cambridge University Press; 2009:331-361.
3. Jurewicz M, Gilbert BR. Imaging and angiography in male factor infertility. Fertil Steril. 2016;105(6):1432-1442.
4. Sigrist RMS, Liau J, Kafas AE, Chammas MC, Willmann JK. Ultrasound elastography: review of techniques and clinical applications. Theranostics. 2017;7(5):1303-1329.
5. De Zordo T, Stronegger D, Pallwein-Prettner L, et al. Multiparametric ultrasonography of the testicles. Nat Rev Urol. 2013;10(3):135-148.
6. Sarteschi LM. Lo studio del varicocele con eco-color-Doppler. G Ital Ultrasonologia. 1993;4:43-49.
7. Turna O, Aybar MD. Testicular stiffness in varicocele: evaluation with shear wave elastography. Ultrasonography. 2020;39(4):350-355.
8. Ahmed AT. Utility of shear wave ultrasound elastography in evaluation of testicular stiffness in patients with varicocele. Egypt J Radiol Nucl Med. 2021;52(1):273.
9. Abdelwahab K, Eliwa AM, Seleem MM, et al. Role of Preoperative Testicular Shear Wave Elastography in Predicting Improvement of Semen Parameters After Varicocelectomy for Male Patients With Primary Infertility. Urology. 2017;107:103-106.