OBJECTIVETo observe the hemodynamic and histological effects of unilateral testicular torsion on the contralateral testis in immature rats, and compare the results of different treatments.

METHODSTesticular torsion models were established in 3-week-old rats and randomized into a normal control, a testicular torsion, a reposition and an orchiectomy group. The systolic peak velocity of the right testicular artery was measured by color Doppler before and 8, 12, 24 and 72 h after the operation. Histological observations of the right testes were performed 2 h after testicular torsion, 12 h after testicular reposition and orchiectomy and when the rats were 9 weeks old.

RESULTSThe blood supply of the immature right testes increased continuously after testicular torsion of the left side. Interstitial edema and ultrastructure changes were observed in the testicular torsion, reposition and orchiectomy groups. The right testis weight was significantly greater in both the testicular torsion and orchiectomy groups than in the normal control group of the 9-week-old rats (P < 0.01). No significant differences were noted in the right testicular seminiferous tubule diameter (STD) , count measure spermatogenic (CMSE) and testicular biopsy score (TBS) among the four groups (P > 0.05).

CONCLUSIONUnilateral testicular torsion increases blood supply and induces histological changes in the contralateral testis in immature rats. Reposition and orchiectomy following light injury are prognostic of similar results.