Ovarian torsion

Summary

Ovarian torsion is the twisting of the ovary and fallopian tube, reducing blood flow and risking infarction. It usually occurs in enlarged ovaries from cysts, tumors, or pregnancy, causing sudden unilateral pain, nausea, vomiting, and a tender mass. Diagnosis is by Doppler ultrasound or laparoscopy, and emergency surgery with detorsion is needed to preserve ovarian function.

Definition

Ovarian torsion, also known as adnexal or tubo-ovarian torsion, is the partial or complete twisting of the ovary and fallopian tube around their supporting ligaments (infundibulopelvic and utero-ovarian ligaments), leading to compromised blood flow and potential ovarian infarction.

Etiology and Risk Factors

The primary risk factor is ovarian enlargement, which predisposes the ovary to twisting. Common causes include:

• Ovarian cysts (particularly >4–5 cm, including dermoid cysts/teratomas)

• Benign ovarian tumors

• Ovarian hyperstimulation syndrome

• Pregnancy, especially following assisted reproductive techniques

• Long or lax ovarian ligaments

• History of pelvic surgery or pelvic inflammatory disease

• Strenuous physical activity

• Previous adnexal torsion
  

Pathophysiology

Twisting of the ovary and fallopian tube compresses ovarian veins and lymphatics, leading to edema. Progressive swelling can compromise arterial flow, causing ischemia, necrosis, and potential loss of ovarian function.

Clinical Features

• Sudden-onset unilateral lower abdominal or pelvic pain, often colicky prior to acute onset

• Nausea and vomiting (up to 70% of cases)

• Palpable, tender adnexal mass

• Abdominal or lower pelvic tenderness

• Symptoms may be preceded by intermittent pain if partial torsion occurs

Diagnosis

• Laboratory tests: Urine or serum β-hCG to rule out pregnancy

• Imaging:

• Pelvic ultrasound with Doppler: First-line; shows enlarged ovary, decreased or absent blood flow, thickened fallopian tube, and twisted vascular pedicle (“whirlpool sign”)

• MRI or CT with contrast: For inconclusive ultrasound; may show ovarian edema, deviation of the uterus, or ascites

• Definitive diagnosis: Laparoscopy is both diagnostic and therapeutic

Management

• Emergency surgical intervention is required, ideally within 6 hours to preserve ovarian function.

• Adnexal detorsion: Untwisting of the ovary; ovary is observed for revitalization.

• Oophoropexy: Fixation of the ovary to prevent recurrence.

• Ovarian cystectomy: Performed if a cyst is present and the ovary is viable.

• Oophorectomy or salpingo-oophorectomy: Reserved for necrotic or gangrenous ovaries; postmenopausal women often undergo salpingo-oophorectomy.