Ovarian torsion

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Background

  • Ovarian torsion is the rotation of the ovary and portion of the fallopian tube on the supplying vascular pedicle
  • Referred to as adnexal torsion and tubo-ovarian torsion
  • Occurs in females of all ages
    • Most common in reproductive age adults
    • In children, it is most common in 9-14 years of age
  • Ovarian cysts (usually > 4 cm) and neoplasms account for 94% of cases in adults[1]
  • Torsion more common on the right, as the sigmoid colon tends to stabilize the left
  • In children, hypermobility of the ovary many be the primary cause of torsion
  • Dual blood supply from ovarian and uterine arteries

Pathophysiology

Torsion occurs from either of two causes:

  1. Hypermobility of the ovary
  2. Adnexal mass
  • Cysts greater than 4 cm are more likely to torse[2]
  • Absence of ovarian Doppler flow is highly specific for torsion, but normal Doppler flow does not completely exclude torsion

Clinical Features

  • Nausea/vomiting (70%)
  • Sudden and sharp pain in the lower abdomen (50%)[3]
    • Can be intermittent and insiduous, especially in those with history of cysts, PCOS[4]
    • Commonly occurs simultaneously with vomiting
    • May occur for days to months intermittently before diagnosis is made[5]
  • Up to 30% have no tenderness on bimanual exam[6]
  • Most adults with ovarian torsion have abnormal or enlarged ovaries that serves as lead point for torsion, but torsion is more likely to occur in normal sized ovaries in pediatrics[7]
    • More than 50% of cases have no palpable adnexal mass[8]
  • Fever (<2%)
  • Up to 20% of cases seen in pregnant women, with most in the 1st trimester and/or received fertility treatments[9]

Differential Diagnosis

RLQ Pain

LLQ Pain

Evaluation

Pelvic exam

  • May not have adnexal TTP or adnexal mass

Doppler Ultrasound

Findings suggestive of torsion may include:

  • Diminished or absent blood flow in the ovarian vessels[10]
    • 2/3 of patients with ovarian torsion have had normal blood flow
    • Venous and lymphatic obstruction occurs before arterial disruption, especially early in disease process[11]
    • Abnormal blood flow, whether venous or arterial, is ~85% sensitive, ~37% specific when not combined with below findings[12]
  • Ovarian mass > 3 cm may be clue
  • Enlarged ovarian volume
    • MC finding
  • Loss of echogenicity
  • Peripherally displaced follicles with hyperechoic central stroma
  • Midline ovary
  • Pelvic free fluid
  • An infarcted ovary may have a more complex appearance with cystic or hemorrhagic degeneration
  • Whirlpool sign of twisted vascular pedicle may be seen but rare[10]

CT Abd/Pelvis

  • CT will not diagnose torsion
  • CT may be used to rule out other possible causes of lower abdominal pain; also exclude presence of pelvic mass
  • Examine for asymmetric ovarian enlargement, which warrants a pelvic US if concerning symptoms exist[13]

Management

  • Emergent OB/GYN consult in ED
    • Consider if high suspicion exists even after equivocal US
  • Surgical detorsion is required to prevent ovarian necrosis
    • If the ovary becomes necrotic, there is a high risk of infection
    • Salvage rate may be high even if time is prolonged beyond several hours of symptoms[14]

See Also

References

  1. Amirbekian S et al. Ultrasound Evaluation of Pelvic Pain. Radiol. Clin. North Am. 2014;52 (6): 1215-1235
  2. M.L. Brandt et al. Surgical indications in antenatally diagnosed ovarian cysts J Pediatr Surg, 26 (1991), pp. 276–282
  3. Houry, D. and Abbott, J.T. Ovarian torsion: a fifteen-year review. Ann Emerg Med. 2001; 38: 156–159.
  4. Damigos, E., Johns, J., and Ross, J. An update on the diagnosis and management of ovarian torsion. Obstet Gynaecol. 2012; 14: 229–236.
  5. Sasaki, K.J. and Miller, C.E. Adnexal torsion: review of the literature. J Minim Invasive Gynecol. 2014; 21: 196–202.
  6. Houry, D. and Abbott, J.T. Ovarian torsion: a fifteen-year review. Ann Emerg Med. 2001; 38: 156–159.
  7. Anders, J.F. and Powell, E.C. Urgency and evaluation and outcome of acute ovarian torsion in pediatric patients. Arch Pediatr Adolesc Med. 2005; 159: 532–535.
  8. Houry, D. and Abbott, J.T. Ovarian torsion: a fifteen-year review. Ann Emerg Med. 2001; 38: 156–159.
  9. Albayram, F. and Hamper, U.M. Ovarian and adnexal torsion: spectrum of sonographic findings with pathologic correlation. J Ultrasound Med. 2001; 20: 1083–1089.
  10. 10.0 10.1 Lee EJ et-al. Diagnosis of ovarian torsion with color Doppler sonography: depiction of twisted vascular pedicle. J Ultrasound Med. 1998;17 (2): 83-9.
  11. Cicchiello, L.A., Hamper, U.M., and Scoutt, L.M. Ultrasound evaluation of gynecologic causes of pelvic pain. Ultrasound Clin. 2010; 38: 85–114.
  12. Cicchiello, L.A., Hamper, U.M., and Scoutt, L.M. Ultrasound evaluation of gynecologic causes of pelvic pain. Ultrasound Clin. 2010; 38: 85–114.
  13. Lourenco, A.P., Swenson, D., Tubbs, R.J. et al. Ovarian and tubal torsion: imaging findings on US, CT and MRI. Emerg Radiol. 2014; 21: 179–187.
  14. Anders JF, Powell EC. Urgency of evaluation and outcome of acute ovarian torsion in pediatric patients. Arch Pediatr Adolesc Med. 2005;159:532–535