Spiral twist of the spermatic cord: a reliable sign of testicular torsion

Background Colour Doppler sonography (CDS) has become the procedure of choice in evaluating testicular perfusion but false negative findings have been reported. Objective. To determine if direct visualisation of the twisted spermatic cord using high resolution US is a reliable sign to assess testicular torsion. Material and methods. Thirty patients (aged 2-26 years) with equivocal diagnosis of testicular torsion prospectively underwent high resolution and CDS. The results were correlated with surgical findings. Serial transverse and longitudinal scans were performed to compare the scrotal contents on each side and study the complete spermatic cord course, from inguinal canal to testis, to detect a spiral twist. Results. In 14 of the 23 cases of torsion, the diagnosis was based on the colour Doppler findings in the scrotum because blood flow was absent in the symptomatic testis and detectable without difficulty on the normal side. In nine cases, CDS was unreliable; in six cases intratesticular perfusion was present in a twisted testis and in three small boys, no colour signal was obtained in either testis. In all cases of torsion, the spiral twist of spermatic cord was detected at the external inguinal ring. The twist induced an abrupt change in spermatic cord course, size and shape below the point of torsion. It appeared in the scrotum as a round or oval, homogeneous or heterogeneous extratesticular mass with or without blood flow, that could be connected cephalad with the normal inguinal cord. In the other seven cases (three late torsions of the appendix testis, one epididymo-orchitis and three torsions with spontaneous reduction), no spiral twist was detectable. Conclusion. The detection of spermatic cord spiral twist appears a reliable US sign of torsion whatever the testicular consequences.