Testis Rigidity Tester: a prototype device for intraoperative detection of changes in testicular pressure and/or elasticity. First experimental experiences.

Abstract

OBJECTIVE: In order to quantitatively evaluate testicular consistency, we designed a device for measurement of testis rigidity, which reflects the resistance caused by testicular pressure and elasticity. The device was tested in experimental models of cryptorchidism and torsion. MATERIALS AND METHODS: The Testis Rigidity Tester (TRT) prototype consists of a system of weights and levers. It measures the force needed for a known deformation of the testis, defined as rigidity. We inhibited testis descent in 10 18-day-old Lewis rats; another 10 age-matched rats underwent sham operation. At the age of 40 days we measured testicular rigidity using the TRT. Additionally, left testes of eight adult Lewis rats underwent 720 degrees torsion; rigidity was measured by the TRT before and 1h after torsion. To investigate repeatability of TRT measurements, the rigidity of five twisted testes was measured 10 times by three researchers. RESULTS: The TRT revealed a significant decrease of rigidity in undescended testes and an increase in twisted testes. Measurements were repeatable, independent of the observer. CONCLUSION: The TRT is a safe, reliable and objective device that successfully measured the altered rigidity in experimental models of testicular disease.