Shear wave elastography evaluation of testes with non-communicating hydrocele in infants and toddlers: A preliminary study.

INTRODUCTION: Shear wave elastography (SWE) is a new technology and non-invasive ultrasound device that can measure tissue rigidity and elasticity.

OBJECTIVE: This controlled prospective study aimed to demonstrate using SWE whether there was a difference between the elasticity of testes with non-communicating (NC) hydrocele in infants and toddlers and elasticity of controls' testes without hydrocele, and to reveal quantitative values of elasticity reflecting histological findings.

MATERIAL AND METHODS: Testes of 37 cases at an average age of 6.32 months and diagnosed with NC hydrocele between December 2016 and April 2017 were evaluated for hydrocele and testicular volumes, and testes elasticity through ultrasonography and SWE.

RESULTS: Of all cases, 15 had bilateral hydroceles, while 22 were diagnosed with unilateral hydrocele. Testes with NC hydrocele (n = 52) in infants and toddlers were compared with testes without hydrocele (n = 36) in controls. Median hydrocele volume of 52 testes with NC hydrocele was 5.0 cm3 (0.2-37). Median volume of testes with hydrocele was 0.6 cm3 (0.2-1.5) in the study group, and 0.5 cm3 (0.3-1) in controls (P = 0.577). Although median elastography values were measured as 1.67 m/s (1.29-2.59) and 10.0 kPa (2.1-23) in patients, those of controls were found to be 1.61 m/s (1.27-2.34) and 8.25 kPa (5.1-18.9) (P = 0.03, P = 0.005, respectively). While there was no between-group difference in testes volumes, a statistically significant difference was observed in SWE-derived quantitative data (Summary Table).

DISCUSSION: As a novel elastographic method, SWE is used to track shear waves passing through tissues by quantifying the elasticity of structures and nodules, such as liver fibrosis, and to improve the characterization of breast and thyroid nodules. Shear wave elastography was assessed to be a beneficial ultrasonography tool to predict the histologic features of undescended testicles, which might replace testicular biopsy in the modern management of undescended testes. This study also quantitatively measured whether there was a change in testicular tissues with NC hydrocele through SWE, and found that SWE values of testes with NC hydrocele were significantly higher compared with those of controls, despite the absence of a significant difference in testes volumes.

CONCLUSIONS: The present study confirmed that quantitative changes in testes elasticity can reliably be evaluated through SWE. Non-communicating hydrocele may be damaging to testicular tissues. More definitive results will be achieved with further comprehensive studies including larger patient populations. It is believed that the operation age of children with NC hydrocele can be re-evaluated in the future.