Spermatic cord torsion. Contralateral testicular degeneration at various ages in the rat.

Unilateral spermatic cord torsion causes damage to the contralateral testis in humans and animals models. It is now known, however, at what age an animal's reproductive capacity is most susceptible to this type of trauma. To determine if the animal's age is a factor in its susceptibility to reproductive damage, rats at 30 to 70 days of age were subjected to unilateral spermatic cord torsion. Rats of the same ages underwent sham surgery and served as controls. The animals were allowed to recover from the surgery and to attain puberty before a period of fertility testing. Fertility, serum testosterone, organ weight, and testicular histologic data were obtained after the breeding period. Our data indicate that animals undergoing torsion at the youngest (30 days) and oldest (70 days) ages exhibited no change in the parameters studied. Animals between the ages of 35 and 50 days are highly susceptible to reproductive damage due to unilateral spermatic cord torsion, and the 35-day-old animals exhibit the most susceptibility. The stages of testicular development occurring during this period are such that damage to one testicle will result in degeneration of both organs. However, once the animal is older than 50 days, its reproductive capacity is not affected by spermatic cord torsion. The specific period of susceptibility in the development of human testes is yet to be defined.

Spermatic cord torsion: effects of cyclosporine and prednisone on fertility and the contralateral testis in the rat.

Unilateral spermatic cord torsion results in contralateral degeneration and reduced fertility in the prepubertal male rat. This study was conducted to investigate the use of immunosuppression with cyclosporine and prednisone to prevent these untoward effects. Thirty-five-day-old male rats were subjected to 720 degrees unilateral spermatic cord torsion of 9 hours duration. At the time of detorsion, animals were given a subcutaneous injection of i) cyclosporine, ii) prednisone, or iii) cyclosporine combined with prednisone. Control groups included: i) animals undergoing orchiectomy of the ipsilateral testis following the torsion period, ii) hemicastration in the absence of torsion and iii) sham surgery. Orchiectomy at the end of the torsion period prevented the torsion induced reduction of fertility, contralateral seminiferous tubule diameter and testis weight. Treatment with cyclosporine combined with prednisone significantly increased these parameters above detorsion alone. These data indicate that short term immunosuppression with cyclosporine alone or in combination with prednisone limits the adverse effects of unilateral spermatic cord torsion as does removal of the damaged organ at the end of the torsion period.

The effect of various degrees of unilateral spermatic cord torsion on fertility in the rat.

Unilateral spermatic cord torsion has been shown to cause damage to the contralateral testis in humans and animal models. In an attempt to explain conflicts among various laboratories concerning the extent of this contralateral effect and to determine the importance of the extent of torsion, prepubertal rats (35 to 40 days) were subjected to unilateral spermatic cord torsion of various degrees (zero to 1440 degrees). Sham surgeries were performed and served as controls (0 degrees of torsion). The animals were allowed to recover from the surgeries and to attain puberty before a period of fertility testing. Fertility, fecundity, organ weight and testicular histological data were obtained after the breeding period. Our data indicate that animals undergoing 360 degrees of torsion exhibited no changes in the parameters studied. However, if 720 degrees, 1080 degrees or 1440 degrees of torsion was induced, a significantly lower percentage of fertile males and pregnant females resulted for each of these experimental groups when compared to those values for the 0 degrees controls. These data indicate that the extent of contralateral testicular degeneration is dependent upon the degree of spermatic cord torsion to which the ipsilateral testis is subjected. The induction of unilateral spermatic cord torsion at 720 degrees or more causes a significant reduction of subsequent fertility while torsion of a lesser degree has little or no effect in the development of this phenomenon.