Ovarian Torsion

Definition: Twisting of vascular pedicle of ovary, fallopian tube, or both → venous obstruction → edema → arterial compromise → ischemia → hemorrhagic infarction

Unilaterally enlarged ovary

• Ovarian volume > 100 mL highly suggestive of torsion

• Ovarian volume < 20 mL in postpubertal patient never torsed in 1 series

• Ratio of abnormal to normal ovarian volumes ≥ 5:1 strongly correlated with torsion in same series

Scattered, predominantly peripheral follicles of 8-12 mm

Ovary may be displaced to midline or contralateral pelvis or abdomen

Sonographic whirlpool sign of twisted vascular pedicle

Variable patterns of Doppler flow within twisted ovary ranging from normal to completely absent

Pelvic free fluid or hemoperitoneum

Urgent surgical detorsion required

• Conservation of ovarian tissue if not frankly necrotic

• > 90% salvage rate of ovarian function

Variable rates of retorsion; oophoropexy controversial

Painful pelvic mass may represent torsed ovary if both normal ovaries not confidently visualized

Doppler exam of ovarian parenchyma may be normal despite true adnexal torsion

• Grayscale findings & high clinical suspicion more predictive

Presence of underlying ovarian cyst/mass can create diagnostic dilemma

• Experienced clinical evaluation key in these cases

Normal symmetric grayscale & Doppler US appearance of ovaries makes ovarian torsion highly unlikely

Twisting of vascular pedicle of ovary, fallopian tube, or both → venous obstruction → edema → arterial compromise → ischemia → hemorrhagic infarction