Ultrasonography.  2020 Apr;39(2):152-158. 10.14366/usg.19055.

Estimating the time of onset of testicular torsion using ultrasonography in an experimental rat model

• Song SH
• Afşarlar
• Xie HW
• Hung AJ
• Koh CJ

• KMID: 2501443
• DOI: http://doi.org/10.14366/usg.19055

Abstract

Purpose
We aimed to document the time of onset of ultrasonographic and histologic changes in the testes of a rat model following testicular torsion.
Methods
Twenty-five Sprague-Dawley rats were divided into four groups. All animals underwent preoperative Doppler ultrasonography. Groups 1, 2, and 3 underwent unilateral surgical torsion of the testis lasting for 72, 24, and 6 hours, respectively. Group 4 underwent a sham operation. The animals were followed with Doppler ultrasonography at 6, 24, 48, and 72 hours postoperatively. Histologic examinations were performed at the designated final time point for each group.
Results
After torsion, enlargement of the epididymal head and thickening of the spermatic cord over time were noted. Based on the ultrasonographic dimensions, the ratio of the epididymal volume increased with time following torsion (p=0.002). The torsed testes had an average weight gain of 0.27 g at 6 hours compared to the control testes, but an average weight loss of 0.22 g at 72 hours (P=0.006). Changes in testicular echotexture were noted as soon as 6 hours after torsion, but there was no consistent pattern of echotexture change thereafter. Histologically, viable tubules were seen 6 hours after torsion, while extensive hemorrhagic necrosis was found at 72 hours.
Conclusion
In evaluating testicular torsion, the enlargement ratio of the epididymis and thickening of the spermatic cord on Doppler ultrasonography may be useful for determining the urgency of immediate surgery. Changes in testicular echotexture may not be a reliable indicator of the time of onset.

Keyword

Testicular torsion; Spermatic cord torsion; Ultrasonography; Testis; Epididymis