False Negative of Doppler Ultrasonography During Testis Torsion in Animal Model

Chang, Hyug Jun; Oh, Yeon Hee; Kim, Dong Hoon; Sohn, Houng Gyu; Ha, Dal Bong; Lee, Kyung Seop

Abstract

PURPOSE: Our aim is to identify the false negative rate of doppler ultrasonography and to compare color doppler ultrasonography with pathologic findings during testis torsion in animal model.
MATERIALS AND METHODS
Seventeen male house rabbits weighted 1.9-2.6kg were examined with doppler ultrasonography as control group and 1 rabbit was orchiectomized as pathologic control group. In 16 rabbits, right spermatic cord was torqued 720o count-clockwise and placed back into the scrotum, and 1, 3, 6, 9, 12, 18, 24, 48 hours after torsion, doppler ultrasonographic and pathologic findings were examined at twisted testicles.
RESULTS
In 1 hour and 3 hours group, false negative rate of doppler ultrasonography were 100% and 6 hours after torsion false nagative rate was 63%. Nine hours after torsion false negative rate was 50%, 12 hours after torsion false negative rate was 25%. But after 18 hours group, all had decreased or disappeared blood flow. Before 9 hours after torsion, there was no pathologic changes in seminiferous tubules. In seminiferous tubules, number of spermatid decreased in 12 hours group and spermatid was absent and spermatocyte were markedly degenerated in 18 hours group. In 48 hours group, spermatid and spermatocyte were absent, number of Sertoli cell decreased markedly and diffuse infarction were seen.
CONCLUSIONS
As time goes by, false negative rate of doppler ultrasonography was decreased. So if blood flow have been normal when doppler ultrasonography was done before 12 hours after torsion, doppler ultrasonography should be re-examined in suspected testis before 12 hours after torsion because of spermatocytes are degenerated after 12 hours.