Ovarian Torsion


Ovarian Torsion, Torsed Ovary

  • Epidemiology
  1. Accounts for 2-3% of acute surgical emergencies (fifth most common gynecologic emergency)
  2. More common in young women (peaks at ages 20 to 30 years)
  3. Torsion occurs outside the reproductive age range and in pregnancy
    1. Torsion occurs in pediatric patients (15% of cases) and Postmenopause (15% of cases)
    2. Ovarian Torsion in pregnancy accounts for 20% of cases
  • Pathophysiology
  1. Partial or complete rotation of ovarian pedicle
    1. Results in lymphatic and venous engorgement in partial rotation, or in early torsion
    2. Results in ischemia or infarction in complete rotation, or in late torsion
  2. Typically unilateral and more commonly right sided
  3. Typically both the ovary and the fallopian tube are involved in the torsion
  4. Enlarged ovary or mass is most common predisposing factor (present in a majority of cases)
    1. However, girls prior to Puberty with Ovarian Torsion typically have normal ovaries
  • Risk Factors
  1. No risk factors in 25% of patients
  2. Prior torsion
  3. Enlarged Ovary
    1. Torsion is uncommon in Polycystic Ovary Syndrome (despite the bilateral enlarged ovaries)
    2. Murakami (2013) Clin Exp Obstet Gynecol 40(4):609-11+PMID: 24597271 [PubMed]
  4. Adnexal Mass
    1. Benign ovarian growths (especially dermoid tumors) have an 11% risk of Ovarian Torsion
    2. Ovarian Cancer has only a 2% risk of Ovarian Torsion
  5. Pregnancy
    1. Related to Adnexal displacement (especially between weeks 6 to 14)
  6. Ovulation induction (Infertility management)
  7. Prior pelvic surgery (including Tubal Ligation)
    1. Adhesions may act at pivot points for torsion
  • Symptoms
  1. Symptoms are initially non-specific
  2. Lower Abdominal Pain (often right sided)
    1. Abrupt onset in only 60% of cases
    2. Severe, progressive unilateral lower Abdominal Pain or Pelvic Pain
    3. Pain is sharp and stabbing in >70% of cases, but may be cramping pain in others
    4. Pain radiates into the thigh, low back or flank
    5. Pain may be intermittent if partial torsion occurs with spontaneous resolution
      1. Up to 40% of patients have had episodes of prior similar pain
  3. Other associated symptoms
    1. Nausea or Vomiting
    2. Low grade fever may be present in up to 20% of patients
  • Signs
  1. Abdominal exam
    1. Frequently benign Abdomen in early cases
    2. Peritoneal signs suggest a longer standing Ovarian Torsion
  2. Pelvic exam (bimanual exam)
    1. Very low sensitivity and Specificity
    2. Uterus may be shifted toward the affected side
    3. Palpable, tender Adnexal Mass in 50% of cases
  1. Findings (combination of factors are most useful in diagnosing or reasonably excluding Ovarian Torsion)
    1. Ovary is larger than 5 cm in >90% of Ovarian Torsion cases
    2. Large edema at ovary in partial Ovarian Torsion
    3. Free pelvic fluid is less common in Ovarian Torsion
    4. Hyperechogenic foci suggest hemorrhagic changes in the ovary
    5. Hypoechogenic foci suggest ovarian edema (most common torsion-related Ultrasound finding)
    6. Cystic, clotted areas suggest infarction
    7. Whirlpool sign (enlarged ovary has a thick, twisted vascular pedicle)
      1. Highly suspicious for Ovarian Torsion
  2. Efficacy
    1. Early studies suggested 93% for Ultrasound abnormality in Ovarian Torsion
    2. More recent studies show variable Test Sensitivity 35-85%
      1. Demonstrates arterial Blood Flow in 50% of Ovarian Torsion cases
      2. Demonstrates venous Blood Flow in 30% of Ovarian Torsion cases
    3. Surprisingly Ultrasound is not appreciably better than CT in identifying Ovarian Torsion
    4. Swenson (2014) Eur J Radiol 83(4): 733-8 +PMID:24480106 [PubMed]
  3. Precautions
    1. Vascular Flow on Color Doppler Ultrasound does not exclude partial Ovarian Torsion
    2. Pelvic Ultrasound need not be done after CT Abdomen specifically to exclude Ovarian Torsion
      1. Ultrasound does not add significant information not seen on CT Abdomen and Pelvis with IV contrast
    3. Ultrasound is sufficient in low to moderate suspicion for torsion cases
      1. Laparoscopy is the only definitive diagnostic tool in high suspicion cases
  • Precautions
  1. Consider Ovarian Torsion in any woman with lower Abdominal Pain
    1. Do not delay surgical Consultation if high level of suspicion
    2. Ultrasound does not have high enough Test Sensitivity to completely exclude torsion
  • Evaluation
  1. High level of suspicion for Ovarian Torsion
    1. Consult Gynecology early
    2. Pelvic Ultrasound (normal result does not exclude high suspicion Ovarian Torsion)
  2. Low to moderate suspicion for Ovarian Torsion
    1. Pelvic Ultrasound is sufficient to evaluate for Ovarian Torsion
    2. CT Abdomen (if done to exclude other causes) is also sufficient to evaluate for torsion
      1. Reflex to pelvic Ultrasound is not needed after CT unless dictated by pathology seen on CT
  3. Intermittent Torsion
    1. Pelvic Ultrasound may show normal Blood Flow
    2. However, intermittent torsion is typically accompanied by Adnexal Mass seen on Ultrasound
  • Management
  1. Gynecologic emergency
    1. Requires prompt diagnosis and treatment for optimal surgical management and ovarian salvage
    2. However, delayed presentation does not exclude a salvageable ovary
  2. Diagnostic laparoscopy if Ovarian Torsion suspected
    1. Often requires conversion to laparotomy if Ovarian Torsion is present
    2. Untwisting and salvage of ovary is safe if no findings suggestive of a necrotic ovary
    3. Oophorectomy is recommended for an infarcted ovary due to the risk of Venous Thromboembolism
  • References
  1. Delaney in Herbert (2016) EM:Rap 16(5): 5-6
  2. Long in Swadron (2023) EM:Rap 23(2): 5-6
  3. Houry (2001) Ann Emerg Med 38:156-9 [PubMed]
  4. Martin (2006) CJEM 8(2):126-9 [PubMed]
  5. Pena (2000) Fertil Steril 73:1047-50 [PubMed]