Prognostic values of shear wave elastography in adolescent boys with varicocele

Intra- and Interobserver Variability in Ultrasound Measurement of Testicular Volumes in Pubertal Boys

Accurate measurement of testicular volume (TV) in boys is an important tool in clinical practice, e.g., in varicocele treatment. This study aims to assess the degree of intra- and interobserver variability of testicular volume measurements. In a prospective study, boys between 11 and 17 years of age without testicular pathology were enrolled. Testicular ultrasound was performed by three investigators (A: pediatric radiologist; B: pediatric surgery/urology resident; C: pediatric urologist). Intraobserver variability was calculated in investigators B and C and interobserver variability between all three investigators. A total of 30 boys were enrolled. Mean intraobserver variability in both observers was +0.3% with a range of -39.6 to 51.5%. The proportion of measurements with a difference >20% was 18.6%. The mean interobserver variability was -1.0% (range: -74.1% to 62.8%). The overall proportion of measurements with a difference >20% was 35%. A lower testicular size of < 4 mL showed a significantly higher rate of >20% difference in both the intraobserver group (31.1% vs. 14.4%; p = 0.035) and the interobserver group (63.2% vs. 26.2%; p = 0.000031). Furthermore, the rate of >20% difference was significantly lower in obese compared to non-obese patients in both the intraobserver (2.8% vs. 22.4%; p = 0.0084) and the interobserver group (24% vs. 40.8%, p = 0.0427). Both intraobserver and interobserver variability in ultrasound-based TV measurements in pubertal boys contain a relevant degree of uncertainty that renders them unsuitable for individualized follow-up care. At the cohort level, however, mean differences in ultrasound-based TV measurements are low enough to make ultrasound comparisons reasonable.

Elastography in the Urological Practice: Urinary and Male Genital Tract, Prostate Excluded—Review

The aim of this article is to review the utility of elastography in the day-to-day clinical practice of the urologist. An electronic database search was performed on PubMed and Cochrane Library with a date range between January 2000 and December 2021. The search yielded 94 articles that passed the inclusion and exclusion criteria. The articles were reviewed and discussed by organ, pathology and according to the physical principle underlying the elastographic method. Elastography was used in the study of normal organs, tumoral masses, chronic upper and lower urinary tract obstructive diseases, dysfunctions of the lower urinary tract and the male reproductive system, and as a pre- and post-treatment monitoring tool. Elastography has numerous applications in urology, but due to a lack of standardization in the methodology and equipment, further studies are required.

Shear Wave Elastography for Assessment of Testicular Stiffness in Patients with Varicocele: A Prospective Comparative Study

Background

The purpose of this study was to use ultrasonography and shear wave elastography (SWE) to assess stiffness and volume of testes in adult patients with varicocele, to compare the results with those of normal contralateral testes of the same patients and healthy testes of control subjects.

Methods

In this IRB-approved prospective comparative study, 58 patients with varicocele (116 testes) and 58 control patients (116 testes) were enrolled. A total of 66 testes with varicocele were added to group A, their 50 healthful contralateral testes were added to Group B, and 116 healthy control testes were added to Group C. Analysis of variance (one way ANOVA) test was used to compare groups and Student's t-test was used for their binary comparisons. The correlation between the testicular stiffness and volume was studied using Pearson's correlation test.

Results

There was not a significant difference in the mean SWE values between three groups and also, between two-group comparisons (P < 0.05). In the mean testicular volumes, a significant difference was observed between Groups A and C (P = 0.028). Conversely, there was not a significant difference between Groups A and B (P = 0.907) or Groups B and C (P = 0.094). A meaningful correlation between testicular stiffness and volume was not detected for each group.

Conclusion

A significant correlation was not determined between SWE values and varicocele, and also between SWE values and testicular volume. We advise that more studies with larger populations of patients are required to verify the effectiveness of SWE in predicting testicular parenchymal damage.

Utility of shear wave ultrasound elastography in evaluation of testicular stiffness in patients with varicocele

Background

Testicular varicocele is the most frequent cause of male infertility. The study aimed at evaluation of testicular stiffness in patients with varicocele measured by shear wave ultrasound elastography (SWE) in correlation to patient semen analysis (total sperm count) and varicocele grade. This case–control study involved 50 patients (40 patients with bilateral testicular varicocele and 10 patients with unilateral Lt. testicular varicocele of different grades) and 25 healthy controls. All participants underwent physical examination, semen analysis (patient group subdivided in two groups: group A; normospermic and group B; oligospermic), scrotal grey scale and Doppler ultrasound, and shear wave ultrasound elastography with measurement of mean testicular stiffness. Evaluation of testicular stiffness and correlation to varicocele grade and semen analysis (total sperm count) were done.

Results

The mean testicular stiffness value measured by SWE in patients with testicular varicocele was greater than that of healthy controls (7.46 ± 1.64 kPa vs. 3.84 ± 0.62 kPa, P < 0.001). The mean testicular stiffness value in group B exceeded that of group A (8.57 ± 1.53 kPa vs. 6.34 ± 1.76 kPa, P = 0.001). A moderate positive correlation was found between mean testicular stiffness value and the varicocele grade (P = 0.01) which was more evident in group B than in group A (P = 0.01).

Conclusions

Testicular ultrasound SWE is a quantitative noninvasive imaging method which helps in the assessment of testicular parenchymal changes due to varicocele. Higher testicular stiffness values were found in testes of patients with varicocele, more in oligospermic patients than the testes of healthy controls. Testicular stiffness is moderately correlated to varicocele grade.

The usefulness of elastography in the evaluation and management of adult men with varicocele: A systematic review

Objective

To review the role of elastography in the evaluation and decision-making of adult, infertile men with varicocele.

Methods

A systematic search using the terms (Elastography) AND (Varicocele), (Stiffness) AND (Varicocele), (Elastography) AND (Male infertility) was performed in Pubmed/Medline. Studies reporting a) elastographic characteristics in varicocele-bearing comparing to normal testicles, and b) the correlation of elastography with varicocele grading, parameters of spermatogenesis, and outcomes of varicocele treatment were selected. Exclusion criteria were animal, adolescents, abstracts, and non-English language studies.

Results

In total, 453 articles were identified; 11 eligible studies were selected. Several modalities were used (shear wave elastography, strain elastography, quasistatic ultrasound elastography, acoustic radiation force impulse). Varicocele-bearing testicles have significantly different stiffness and elasticity in comparison to normal and non-varicocele testicles. Although not in full agreement, elastography readings are correlated with semen parameters. Conflicting results were reported regarding grading as most of the studies failed to demonstrate a significant correlation. Shear wave elastography showed a significant correlation with the improvement in semen parameters after varicocelectomy, but the association with pregnancy rates is unknown. Finally, no studies were identified comparing elastography with other modalities.

Conclusions

Elastography can detect changes in the architecture of varicocele-bearing testicles. Although the role of the modality in grading is uncertain, elastography showed a meaningful correlation with spermatogenesis parameters. Importantly, elastography readings could predict the improvement in semen parameters after varicocelectomy which is useful in terms of decision-making in infertile men with varicocele.

Abbreviations

ARFI: acoustic radiation force impulse; CDUS: colour Doppler ultrasonography; DWI: diffusion-weighted imaging; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; SWE: shear wave elastography; VC: varicocele.

Causal contributors to tissue stiffness and clinical relevance in urology

Mechanomedicine is an emerging field focused on characterizing mechanical changes in cells and tissues coupled with a specific disease. Understanding the mechanical cues that drive disease progression, and whether tissue stiffening can precede disease development, is crucial in order to define new mechanical biomarkers to improve and develop diagnostic and prognostic tools. Classically known stromal regulators, such as fibroblasts, and more recently acknowledged factors such as the microbiome and extracellular vesicles, play a crucial role in modifications to the stroma and extracellular matrix (ECM). These modifications ultimately lead to an alteration of the mechanical properties (stiffness) of the tissue, contributing to disease onset and progression. We describe here classic and emerging mediators of ECM remodeling, and discuss state-of-the-art studies characterizing mechanical fingerprints of urological diseases, showing a general trend between increased tissue stiffness and severity of disease. Finally, we point to the clinical potential of tissue stiffness as a diagnostic and prognostic factor in the urological field, as well as a possible target for new innovative drugs.

Role of multiparametric ultrasound in testicular focal lesions and diffuse pathology evaluation, with particular regard to elastography: Review of literature

BACKGROUND

Ultrasound is the main requested technique for the assessment of traumatic, vascular, neoplastic, and inflammatory testicular pathology. Moreover, the role of ultrasound has broadened over the years along with the introduction of new techniques, such as contrast enhanced ultrasound and ultrasound elastography.

OBJECTIVE

An updated representation of the pre-existing Literature evidence for multiparametric ultrasound imaging with particular regard to elastography, in the evaluation of focal and diffuse testicular pathologies, has been presented.

METHODS

The search was performed in PubMed, Cochrane, EMBASE, Web of Science and Scopus databases from the earliest available article (1977) until January 2021. Based on the evidence of the Literature, the current role of US imaging for focal and diffuse testicular pathologies has been reported and illustrated, with emphasis on examination technique, classification, and pitfalls.

RESULTS

Multiparametric Ultrasound has a recognized role for testicle focal and diffuse disease. Elastography is nowadays recognized as an essential part of the multiparametric ultrasound examination. However, in the setting of testicular pathology this method showed some promising results in the setting of varicocoele and for focal lesions characterization. In the remaining field its role is still under debate.

DISCUSSION

B-mode ultrasound and color Doppler ultrasound have been for a long time the diagnostic gold standard for testicular pathologies. The introduction of both contrast enhanced ultrasound and elastography in the last two decades has brought to the emergence of the multiparametric ultrasound concept. These methods are currently able to increase diagnostic confidence especially for testicular lesions characterization, with different relevance depending on the pathology under consideration.

CONCLUSION

Multiparametric ultrasound testis assessment, with specific regard to elastography is nowadays recommended for focal and diffuse disease evaluation. Further and larger studies are however needed to validate these results and to understand if the role of elastography in testicular pathology may be broadened.

A preliminary study of shear-wave elastography for the evaluation of varicocele in adolescents and young adults

PURPOSE

The purpose of this study was to use shear-wave elastography (SWE) to assess testicular stiffness changes during the Valsalva maneuver in adolescents and young adults with varicocele, to compare these changes according to clinical severity, and to evaluate the role of SWE in the diagnosis of varicocele.

METHODS

This study included patients undergoing testicular ultrasonography for the diagnosis of varicocele or for post-varicocelectomy follow-up between June 2016 and February 2017. Fifty-four testicles of 27 consecutive patients (mean age, 15.9 years) were classified by clinical grade (grade 0-3). Using SWE, mean testicular stiffness (Emean) was measured at rest and during the Valsalva maneuver. The correlations between multiple ultrasonographic parameters (volume asymmetry, Emean at rest, and absolute and percentage changes in Emean during the Valsalva maneuver) and clinical grade were assessed using the Spearman correlation test.

RESULTS

The Emean at rest was similar across clinical grades. During the Valsalva maneuver, increased testicular stiffness was frequently observed in patients with grade 2 or 3 varicocele but rarely observed in those with grade 0 or 1 varicocele. The changes in Emean were positively correlated with the clinical grade (all P<0.001), whereas the Emean at rest and volume asymmetry were not (all P>0.05).

CONCLUSION

A transient, reversible increase in testicular stiffness during the Valsalva maneuver was observed in adolescents with high-grade varicocele, and the degree of stiffness change was correlated with the clinical grade. Stiffness change identified using SWE during the Valsalva maneuver is a potential surrogate indicator of venous congestion.

The relationship of the shear wave elastography findings of patients with unilateral lumbar disc herniation and clinical characteristics

Background

The aim of this study was to find out whether the shear wave elastography (SWE) findings of patients with unilateral lumbar disc herniation (LDH) were related to clinical characteristics.

Methods

For this purpose, the study group included patients (N = 20; 13 male, 7 female) with complaints of unilateral sciatica, with foraminal stenosis caused by one level of LDH (L4-L5 or L5-S1). An gender-and age-matched control group (N = 27; 16 male, 11 female) was included. All the patients were examined on both the axial and longitudinal planes bilaterally at the same level using a convex array probe (1- 6 MHz, Supersonic Imagine, Aix en Provence, France).

Results

The sciatic nerve stiffness measured on longitudinal planes of the affected side was significantly higher than unaffected side (p < 0.001) and the control group (P < 0.05). Furthermore, the symptom duration of unilateral LDH is positively correlated with the stiffness the sciatic nerve (r = 0.52, p = 0.019).

Conclusion

According to these findings, ultrasound imaging can be considered as a useful tool to detect changes in the sciatic nerve due to disc herniation. This technique will have a promising prospect for many patients with unilateral LDH in monitoring stiffness during rehabilitation and before or after surgery.

Management and Treatment of Varicocele in Children and Adolescents: An Endocrinologic Perspective

Pediatric varicocele has an overall prevalence of 15%, being more frequent as puberty begins. It can damage testicular function, interfering with Sertoli cell proliferation and hormone secretion, testicular growth and spermatogenesis. Proper management has a pivotal role for future fertility preservation. The aim of this review was to discuss the diagnosis, management and treatment of childhood and adolescent varicocele from an endocrinologic perspective, illustrating the current evidence of the European Society of Pediatric Urology (ESPU), the European Association of Urology (EAU), the American Urological Association (AUA) and the American Society for Reproductive Medicine (ASRM) scientific societies. According to the ASRM/ESPU/AUA practice committee, the treatment of adolescent varicocele is indicated in the case of decreased testicular volume or sperm abnormalities, while it is contraindicated in subclinical varicocele. The recent EAS/ESPU meta-analysis reports that moderate evidence exists on the benefits of varicocele treatment in children and adolescents in terms of testicular volume and sperm concentration increase. No specific phenotype in terms of testicular volume cut-off or peak retrograde flow (PRF) is indicated. Based on current evidence, we suggest that conservative management may be suggested in patients with PRF < 30 cm/s, testicular asymmetry < 10% and no evidence of sperm and hormonal abnormalities. In patients with 10-20% testicular volume asymmetry or 30 < PRF ≤ 38 cm/s or sperm abnormalities, careful follow-up may ensue. In the case of absent catch-up growth or sperm recovery, varicocele repair should be suggested. Finally, treatment can be proposed at the initial consultation in painful varicocele, testicular volume asymmetry ≥ 20%, PRF > 38 cm/s, infertility and failure of testicular development.