Ovarian torsion

Ovarian torsion

Arteries of the female reproductive tract: uterine artery, ovarian artery and vaginal arteries. (Ovary and ovarian artery visible in upper right.)
Classification and external resources
ICD-10 N83.5
ICD-9 620.5
DiseasesDB 31120
eMedicine article/795994

Ovarian torsion (OT) refers to the rotation of the ovary at its pedicle to such a degree as to occlude the ovarian artery and/or vein.

Epidemiology

Ovarian torsion accounts for about 3% of gynecologic emergencies. The incidence of ovarian torsion among women of all ages is 5.9 per 100,000 women, and the incidence among women of reproductive age (15−45 years) is 9.9 per 100,000 women.[1] In 70% of cases, it is diagnosed in women between 20 and 39 years of age. The risk is greater during pregnancy and in menopause. Risk factors include increased length of the ovarian ligaments, pathologically enlarged ovaries (more than 6 cm), ovarian masses or cysts, and enlarged corpus luteum in pregnancy.

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 and vomiting.[2]

Use of Doppler ultrasound in the diagnosis has been suggested.[3][4] However, doppler flow is not always absent in torsion- the definitive diagnosis is often made in the operating room.[5]

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, although in rare cases the ovary rotates around the mesovarium or the fallopian tube rotates around the mesosalpinx. 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 obstetrics and gynaecology department found that preoperative diagnosis of ovarian torsion was confirmed in only 46% of patients.[6] Gynecologic ultrasonography is the imaging modality of choice.[7]

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 study).[6] The sensitivity and specificity of abnormal ovarian flow for OT are 44% and 92%, respectively, with a positive and negative predictive value of 78% and 71%, respectively.[6] Specific flow features on Doppler sonography include:[7]

Normal vascularity does not exclude intermittent torsion. There may occasionally be normal Doppler flow because of the ovary's dual blood supply from both the ovarian arteries and uterine arteries.

Other ultrasonographic features include:[7]

The use of plasma D-dimer level has been studied in the diagnosis of torsion. With a cut-off value 0.65 mg/ml, the sensitivity in determining adnexal/ovarian torsion was found to be 71.4%. Specificity was 85%.[8]

Treatment

Surgical treatment of ovarian torsion includes laparoscopy to uncoil the torsed ovary and possibly oophoropexy to fixate the ovary which is likely to twist again. In severe cases, where blood flow is cut off to the ovary for an extended period of time, necrosis of the ovary can occur. In these cases the ovary must be surgically removed.

References

  1. ↑ Yuk J-S, Kim LY, Shin J-Y, et.al. A national population-based study of the incidence of adnexal torsion in the Republic of Korea. Int J Gynaecol Obstet 2015. doi:10.1016/j.ijgo.2014.11.027. PMID 25721499
  2. ↑ eMedicine. "Ovarian Torsion: Overview." http://emedicine.medscape.com/article/795994-overview
  3. ↑ Peña JE, Ufberg D, Cooney N, Denis AL (May 2000). "Usefulness of Doppler sonography in the diagnosis of ovarian torsion". Fertil. Steril. 73 (5): 1047–50. doi:10.1016/S0015-0282(00)00487-8. PMID 10785237.
  4. ↑ Zanforlin Filho SM, Araujo Júnior E, Serafini P et al. (April 2008). "Diagnosis of ovarian torsion by three-dimensional power Doppler in first trimester of pregnancy". J. Obstet. Gynaecol. Res. 34 (2): 266–70. doi:10.1111/j.1447-0756.2008.00768.x. PMID 18412795.
  5. ↑ Tintinalli, Judith (2004). Emergency Medicine. McGraw Hill Professional. p. 904. ISBN 978-0-07-138875-7.
  6. ↑ 6.0 6.1 6.2 Bar-On S, Mashiach R, Stockheim D et al. (April 2010). "Emergency laparoscopy for suspected ovarian torsion: are we too hasty to operate?". Fertil. Steril. 93 (6): 2012–5. doi:10.1016/j.fertnstert.2008.12.022. PMID 19159873.
  7. ↑ 7.0 7.1 7.2 Ovarian torsion at Radiopaedia. By Dr Yuranga Weerakkody and Dr Andrew Dixon et al. Retrieved Feb 2014
  8. ↑ Incebiyik, A; Camuzcuoglu, A; Hilali, N. G.; Vural, M; Camuzcuoglu, H (2014). "Plasma D-dimer level in the diagnosis of adnexal torsion". Journal of Maternal-Fetal and Neonatal Medicine: 1–4. doi:10.3109/14767058.2014.942636. PMID 25007989.