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

Using shear wave elastography method to evaluate testicular compartment syndrome after testicular torsion

The measurement of compartment pressure is a direct method to objectively evaluate suspected compartment syndrome. However, to evaluate the evolving compartment syndrome, one needs to measure the pressure repeatedly, which may aggravate the damage of tissue. Despite several suggested approaches, an effective, noninvasive and sustainable method to detect testicular compartment syndrome is still lacking. In this context, using the method of shear wave elastography, we assessed the correlation between the intratesticular pressure and the testicular compartment elasticity (Emean) after testicular torsion in rabbits. It was found that a strong correlation between the intratesticular pressure and the Emean in the testicular border area (p < .001) or the central area (p = .001) was present. This result suggests that shear wave elastography is a reliable method to evaluate intratesticular pressure in rabbits, and it may have further potential clinical application in detecting testicular compartment syndrome.

A diagnostic model for histologic damage in undescended testes based on testis rigidity measurement: an experimental study with a novel device

BACKGROUND

We aimed to test whether testis rigidity (hardness) measured using a newly-designed device we previously introduced would offer more reliable assessment of histologic damage in undescended testes than conventional methods (consistency feel at palpation, volume measurement).

MATERIALS AND METHODS

Forty-five 18-d-old Lewis rats underwent surgical inhibition of descent of left testes and were followed to 40 (n = 16), 63 (n = 14), or 90 days (n = 15). Another 45 18-d-old Lewis rats were sham operated (left side) and followed likewise (n = 14, n = 15, and n = 16). At the designated time points, testes were exposed bilaterally, rigidity was measured, and consistency at palpation was scored; testes were removed and subjected to length, width, weight measurements, volume calculation, and histomorphometry (mean Johnsen score [MJS], mean tubular diameter [MTD], and mean capsule width [MCW]). Testes of experimental group were compared with ipsilateral testes of sham-operated rats.

RESULTS

At all time points, undescended testes had decreased rigidity, MJS, and MTD, increased MCW, decreased volume and weight; contralateral testes remained unaffected. Rigidity was associated only with MJS and MTD, and most strongly with MJS (multiple stepwise linear regression, F = 694.44, P < 0.0005). MJS could be precisely predicted from rigidity: MJS = 0.699 × testis rigidity (F = 1358.82, P < 0.0005). This model showed good fit between predicted and actual MJS values (R(2) = 0.94), low error, nonsignificant bias, sensitivity 75% and specificity 90%. Model validation showed low prediction error and nonsignificant bias, indicating generalizability. Testis volume and palpation proved imprecise MJS predictors.

CONCLUSIONS

Testis rigidity is an effective predictor of histologic damage in rat undescended testes, with diagnostic value superior to testis palpation scoring and volume measurement.