Originally published at Pediatric EM Morsels on January 24, 2015. Reposted with permission.

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We all know that abdominal pain is a common complaint that in the ED.  The differential is vast and includes some terrible conditions (ex, Intussusception,Necrotizing Enterocolitis, Malrotation) as well as rather common conditions (ex,Constipation).  Naturally, we have all been taught to think “outside the box” and know to consider conditions outside the abdominal cavity (ex, Pneumonia, Testicular Torsion). When we are thinking outside of the box, make sure we keep Ovarian Torsion on our DDx list for the young girls.

Ovarian Torsion Basics

• It is rare (Estimated at ~4.9 cases per 100,000).

• Caused by the ovary rotating around its supportive ligaments.
• Leads to occlusion of the lymphatics and vascular structures.
• Most commonly occurs on the right side (great, another appendicitis mimic).

• 58% of the time the ovary has no obvious pathology as the cause of the torsion.
• Risk of torsion is related to size of mass or cyst if known; 4-5cm is significant.

Ovarian Anatomy Matters

• The ovary receives blood from two sources – the ovarian and uterine arteries.
• As the ovary twists, it will first compromise lymphatic drainage, leading to swelling.
• This can then compromise venous flow, worsening engorgement.
• Since there are two arterial supplies, even with significant and prolonged torsion,there still may be arterial flow.
  • This is important to remember when considering the ultrasound results!

Ovarian Torsion in Kids

• Children account for only 15% of all of the cases of Ovarian Torsion.
• Has been described in all age groups.
  • < 1 year of age – 16% of cases
  • 1 – 8 years of age – 18% of cases
  • 9 – 14 years of age – 52% of cases
  • 15 – 19 years of age – 14 % of cases
• Younger children often reported has being more likely to have neoplasm, but actually most likely to have normal ovaries.
• Infants may have been diagnosed in utero with ovarian cysts by ultrasound.  Ask about this when evaluating abdominal pain.

Ovarian Torsion Presentation

• Classically, presents with sudden onset of severe, unilateral pain that is constant.
• Unfortunately, the pain can be intermittent for spontaneous torsion and detorsion.
• Vomiting that occurs with pain is concerning for it (60% of patients have been documented with this).
• Younger children, obviously, are more difficult to diagnose.

• Ovarian Torsion has many mimics and is, therefore, often missed at first.
• Appendicitis and Ovarian Torsion overlap in presentation and are difficult to distinguish on exam.
  • One study found Ovarian Torsion cases had a lower WBC, CRP, and Alvarado Score.
  • While I am not a huge advocate for these tests for appendicitis, they may be helpful when considering other entities.
  • Or, if your evaluation for appendicitis is negative, you can also make yourselfreconsider Ovarian Torsion.

• Duration of symptoms

  • Prolonged symptoms do not predict poor outcome.
    • Salvage rates are equal to oophorectomy rates despite prolonged times.
  • Do not diminish your concern because it has been 48 or even 72 hours.
    • The initial diagnosis is difficult to make and may have been missed.
    • The ovary still may be salvageable.

The Ultrasound!

• This is the diagnostic study of choice currently, but it has limitations!
• In prepubescent and nonsexually active females, transabdominal U/S is useful.
  • A full bladder can help with the image quality.
• Transvaginal U/S is preferred for older, sexually active females.

• Because the Ovary has two blood supplies, the U/S may show normal arterial flow.
  • 2/3 of patients with ovarian torsion have had normal blood flow.
• Most common finding is an enlarged ovary or adnexal mass.
• The ovary can also show multiple cortical follicles.
• Rarely is the “whirlpool sign” seen – twisted vessels in the ovarian pedicle.

• The U/S is often abnormal with enlargement or obvious cyst(s); however, DO NOT rely on arterial blood flow.

Moral of the Morsel:

Ovarian Torsion is another entity that requires us to be vigilant and reconsider our DDx.  Do not allow diagnostic momentum obscure the possibility of the ovary being the primary issue.  Also, if your history and your exam make you concerned for it, do not allow “normal doppler blood flow” to remove ovarian torsion from your differential.

References