The effects of twisted ischaemic adnexa managed by detorsion on ovarian viability and histology: an ischaemia-reperfusion rodent model

This prospective controlled follow-up study was designed to examine the eff ects of adnexal torsion on long-term ovarian histology and radical scavenge r (FRS) activity, and subsequent viability following the detorsion of twist ed ischaemic adnexa, in a primate centre of a university clinic. Adnexal to rsion/occlusion was created by twisting the adnexa three times and fixing o n to the side wall or by applying vascular clips in cycling female rats at 70 days of age. Following an ischaemic period of 4 to 36 h, the twisted adn exas were surgically removed and fixed. In the second group of rats, follow ing the above ischaemic periods, the torsion/occlusion were relieved by det wisting or removing the vascular clips. Then the animals were reperfused fo r a week and adnexas were extirpated. After both ischaemia and reperfusion, the removed adnexas were examined histologically and tissue concentrations of glutathione peroxidase, superoxide dismutase, catalase and glutathione were determined. Regardless of the ischaemia time, all the twisted adnexas were black-bluish in appearance. Despite the gross ischaemic-haemorrhagic f eatures, histological sections revealed negligible changes, with intact ova rian structure similar to controls in 4-24 h groups. Though decreased compa red with controls, the change in tissue concentrations of FRS was not signi ficant in 4-24 h groups. Only the 36 h group showed prominent congestion on all sections and a significant decrease in all radical scavenger concentra tions studied. While no longterm reperfusion injury was observed histologic ally in 4-24 h groups, the 36 h group ended with adnexal necrosis. Our find ings support the importance of early diagnosis and conservative surgical ma nagement (detorsion) in adnexal torsion. Lack of histological changes and u nimpaired FRS metabolism are consistent with the recent data that vascular compromise is caused by venous or lymphatic stasis in early torsion and tha t adnexal integrity is not correlated with gross ischaemic appearance, thus providing evidence of adnexal resistance against ischaemia.