OBJECTIVETo investigate the protective effect of retarded removal of the unilateral necrotic testis after long-time (> 24 h) spermatic cord torsion on the contralateral testis in rats.

METHODSThirty-three male SD rats aged 21 -42 days were divided into a sham-operation group (n = 11), a torsion-reservation group (n = 12) and a torsion-orchiectomy group (n = 10). The rats of the sham-operation group received dartos pouch orchidopexy on the left testis, while those of the latter two groups underwent 720 degrees unilateral spermatic cord torsion on the left side. Ninety-six hours later, the rats of the torsion-reservation group received detorsion with the ipsilateral testis preserved, while those of the torsion-orchiectomy group underwent orchiectomy. Three months after operation, blood samples were obtained from the rats for measurement of serum testosterone and antisperm antibodies by ELISA, and meanwhile testes and epididymides were harvested for determination of the volumes of various structures and the diameter of seminiferous tubules with stereological methods.

RESULTSThere were no significant differences in the level of serum testosterone among the three groups. Anti-sperm antibody positive was found in only 1 animal in the torsion-reservation group. The Leydig cell nuclei in the contralateral testis appeared larger in the torsion groups than in the sham-operation group. Marked morphological changes were observed in 1, 3 and 0 of the animals in the sham-operation, torsion-reservation and torsion-orchiectomy group, respectively, mainly including atrophy of seminiferous tubules and reduced number of spermatogenic cells. The volume of the contralateral testis was increased by 19% and 21% in the torsion-reservation and torsion-orchiectomy group, respectively, in comparison with that in the sham-operation group (P < 0.05). No significant differences were observed in the volume of seminiferous tubules of the contralateral testis among the sham-operation, torsion-reservation and torsion-orchiectomy groups ([1.15 +/- 0.07], [1.30 +/- 0.04] and [1.35 +/- 0.05] cm3). The volume of the interstitial tissue was significantly increased in the latter two groups ([0.36 +/- 0.02 and 0.34 +/- 0.03] cm3) as compared with the former ([0.25 +/- 0.02] cm3) (P < 0.05). The diameters of the seminiferous tubules exhibited no significant differences among the three groups ([226.00 +/- 7.00], [223.00 +/- 6.00] and [221.00 +/- 3.0] microm).

CONCLUSIONLong-time unilateral spermatic cord torsion may result in compensatory hypertrophy of the contralateral testis, and orchiectomy does not significantly affect the histology of the contralateral testis and epididymis.