Ovarian torsion refers to the rotation of the ovary

Ovary

The ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in anatomically female individuals are analogous to testes in anatomically male individuals, in that they are both gonads and endocrine glands.-Human anatomy:Ovaries...

 to such a degree as to occlude the ovarian artery

Ovarian artery

In human anatomy, the ovarian artery is a blood vessel that supplies oxygenated blood to the ovary. It arises from the abdominal aorta below the renal artery, and does not pass out of the abdominal cavity. It can be found in the suspensory ligament of the ovary, anterior to the ovarian vein and...

 and/or vein.

Epidemiology

Ovarian torsion accounts for about 3% of gynecologic emergencies. In 70 percent, it is diagnosed in women between 20 and 39 years. The risk is greater during pregnancy and in the menopause. The risk factors are increased length of the ovarian ligaments, pathologically enlarged ovaries (more than 6 cm), tumors, enlarged corpus luteum

Corpus luteum

The corpus luteum is a temporary endocrine structure in mammals, involved in production of relatively high levels of progesterone and moderate levels of estradiol and inhibin A...

 in pregnancy and jerky movements.

Presentation

Patients with ovarian torsion often present with sudden onset of sharp and usually unilateral lower abdominal pain, in 70% of cases accompanied by nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

 and vomiting

Vomiting

Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

. In case of necrosis, fever

Fever

Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

 occurs.

Use of Doppler ultrasound  in the diagnosis has been suggested.

Pathophysiology

The development of an ovarian mass is related to the development of torsion. In the reproductive years, regular growth of large corpus luteal cysts are a risk factor for rotation. The mass effect of ovarian tumors is also a common cause of torsion. Torsion of the ovary usually occurs with torsion of the fallopian tube as well on their shared vascular pedicle around the broad ligament

Broad ligament of the uterus

The broad ligament of the uterus is the wide fold of peritoneum that connects the sides of the uterus to the walls and floor of the pelvis.-Subdivisions:The broad ligament may be divided into three subcomponents:...

, although in rare cases the ovary rotates around the mesovarium

Mesovarium

The mesovarium is the portion of the broad ligament of the uterus that covers the ovaries.At first the mesonephros and genital ridge are suspended by a common mesentery, but as the embryo grows the genital ridge gradually becomes pinched off from the mesonephros, with which it is at first...

 or the fallopian tube rotates around the mesosalpinx

Mesosalpinx

The mesosalpinx is part of the lining of the abdominal cavity in higher vertebrates, specifically the portion of the broad ligament that stretches from the ovary to the level of the uterine tube....

. In 80%, torsion happens unilaterally, with slight predominance on the right.

Diagnosis

Ovarian torsion is difficult to diagnose accurately, and operation is often performed before certain diagnosis is made. A study at an Israeli obstetrics and gynaecology

Obstetrics and gynaecology

Obstetrics and gynaecology are the two surgical–medical specialties dealing with the female reproductive organs in their pregnant and non-pregnant state, respectively, and as such are often combined to form a single medical specialty and postgraduate training programme...

 department found that preoperative diagnosis of ovarian torsion was confirmed in only 46% of patients.

Lack of ovarian blood flow on Doppler sonography seems to be a good predictor of ovarian torsion. Women with pathologically low flow are more likely to have OT (77% vs. 29% in an Israeli study). The sensitivity and specificity

Sensitivity and specificity

Sensitivity and specificity are statistical measures of the performance of a binary classification test, also known in statistics as classification function. Sensitivity measures the proportion of actual positives which are correctly identified as such Sensitivity and specificity are statistical...

 of abnormal ovarian flow for OT are 44% and 92%, respectively, with a positive

Positive predictive value

In statistics and diagnostic testing, the positive predictive value, or precision rate is the proportion of subjects with positive test results who are correctly diagnosed. It is a critical measure of the performance of a diagnostic method, as it reflects the probability that a positive test...

 and negative predictive value

Negative predictive value

In statistics and diagnostic testing, the negative predictive value is a summary statistic used to describe the performance of a diagnostic testing procedure. It is defined as the proportion of subjects with a negative test result who are correctly diagnosed. A high NPV means that when the test...

 of 78% and 71%, respectively.

Treatment

Conservative treatment of ovarian torsion includes laparoscopy

Laparoscopy

Laparoscopy is an operation performed in the abdomen or pelvis through small incisions with the aid of a camera...

 to uncoil the torsed ovary and possibly oophoropexy to fixate the ovary which is likely to torse again. In severe cases, where blood flow is cut off to the ovary for an extended period of time, necrosis

Necrosis

Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...

of the ovary can occur. In these cases the ovary must be surgically removed.