I read with interest the review on the update of diagnosis and management of ovarian torsion in the most recent edition of TOG. When discussing ovarian torsion in gynaecology, we often compare it to testicular torsion. As discussed in the review,1 in men this is treated as an acute surgical emergency, within 6 hours. The reason for this is that testicles have a higher metabolic activity, as they are continuously producing millions of spermatozoa. This high metabolic activity makes them particularly sensitive to hypoxia that occurs during torsion. Also the single testicular artery in the pedicle is the sole blood supply to the organ. There is a blood-testis barrier that prevents the cellular immune system from coming into contact with the spermatozoa producing cells. Breakdown of this barrier leads to antibody formation against them. The antibodies can cross the blood-testis barrier of the neighbouring unaffected testicle and cause sympathetic orchitis. Sympathetic orchitis could lead to male infertility. There is one more situation where such a response can occur: in the eye. Ophthalmic trauma can cause sympathetic ophthalmitis in the opposite normal eye, which can result in bilateral blindness. An immune barrier does not exist in the ovary.
Certainly, the ovaries being intra-abdominal organs are less accessible for diagnosis of ovarian torsion than the testicles. Clinical presentation is non-specific and the differentials include a long list of possible diagnoses. Inevitably, the time to diagnosis is much longer. However, considering the positive data on detorsion discussed in the review,1 we need to consider possible hypothesis for this observation. With regards to the ovary the vascular supply is mainly from the ovarian artery in the pedicle but also a variable number of collateral vessels that form with its anastomosis with the uterine artery. Within the ovario-pelvic ligament and of the broad ligament of the uterus, there are a number of smaller vessels that fan into the ovarian cortex and these may play a larger role if the main blood supply is interrupted due to hypoxia mediated local vascular bed dilatation. It may also be that the metabolic rate of ovarian tissue is lower compared to the testis, making it more resistant to hypoxia.
Also there is limited data on ovarian preservation following detorsion after variable lengths of hypoxia. Further research on the ovary's response to hypoxia is needed to establish how the ovary is affected by ischemia and limits of viability.