In a reproductive‑age female presenting with intermittent unilateral lower abdominal or flank pain suggestive of ovarian torsion, what is the appropriate work‑up and treatment?

Work-Up and Treatment of Intermittent Ovarian Torsion

Immediately obtain combined transvaginal and transabdominal pelvic ultrasound with color and spectral Doppler as the first-line diagnostic study, and proceed urgently to laparoscopic detorsion if imaging findings are consistent with torsion, regardless of whether arterial flow is present. 1, 2

Clinical Recognition

Intermittent ovarian torsion presents with severe, constant pain that fluctuates in intensity but rarely resolves completely without intervention. 1, 3 The pain is typically unilateral lower abdominal or flank pain, often accompanied by nausea and vomiting (occurring in 70% of cases). 4

Critical pitfall: The pain pattern may mimic renal colic, appendicitis, or urinary tract infection, leading to diagnostic delays. 1, 3, 5 Maintain high clinical suspicion even when symptoms suggest alternative diagnoses.

Diagnostic Work-Up Algorithm

First-Line Imaging: Combined Ultrasound Approach

Perform both transvaginal and transabdominal ultrasound together with color and spectral Doppler, systematically documenting ovarian size, masses, peripheral follicle pattern, whirlpool sign, and both arterial and venous flow characteristics. 1, 2

Key ultrasound findings to identify:

• Unilaterally enlarged ovary (>4 cm or volume >20 cm³) — present in up to 74% of cases 1, 2
• Peripheral follicles in a "string of pearls" pattern — found in 74% of cases 1, 2
• Whirlpool sign (twisted vascular pedicle) — 90% sensitivity when present 1, 3, 2
• Abnormal or absent venous flow — 100% sensitivity, 97% specificity 1, 2

Most critical diagnostic pitfall: Normal arterial blood flow does NOT rule out ovarian torsion, as torsion can be intermittent or partial, and venous flow abnormalities are more sensitive. 1, 3 The combined ultrasound approach with Doppler achieves 96% overall accuracy. 2

Second-Line Imaging When Ultrasound Is Inconclusive

When ultrasound findings are equivocal but clinical suspicion remains high, proceed to MRI (80-85% sensitivity, no radiation exposure) as the preferred second-line modality. 1, 2 MRI findings include enlarged ovary with stromal edema, surrounding fluid, and absent or diminished enhancement. 1

Alternatively, use CT abdomen/pelvis with IV contrast (74-95% sensitivity, 80-90% specificity) if MRI is unavailable or when non-gynecologic pathology is in the differential. 3, 2 CT findings include asymmetrically enlarged ovary, twisted pedicle, abnormal or absent ovarian enhancement, deviation of uterus to the affected side, and engorged vessels on the twisted side. 1, 3, 6

Treatment Algorithm

Immediate Surgical Management

The standard of care requires immediate laparoscopic detorsion with ovarian preservation, even when the ovary appears necrotic. 1 Intraoperative visual assessment of ovarian viability is highly inaccurate, with only 18-20% of ovaries that appear necrotic being actually necrotic on pathological examination. 1

Surgical approach:

• Perform urgent gynecologic consultation for laparoscopic surgery once diagnosis is suspected 1, 4
• Proceed with laparoscopic detorsion to uncoil the twist and restore blood flow 3, 7
• Preserve the ovary regardless of macroscopic appearance 3

When to consider oophorectomy:

• Definitive necrosis with no signs of recovery after detorsion 3
• Large malignant masses 3
• Postmenopausal women 3

Special Consideration: Pregnancy

In pregnant patients with suspected torsion, maintain an even higher index of suspicion because 38-60% of pregnant patients with torsion have normal Doppler flow on ultrasound. 8 Proceed directly to surgery for symptomatic cases, as elective surgery is safer than emergent surgery (1% vs 5% fetal loss rate). 8 Patients who undergo detorsion alone have higher recurrence rates (4-15%) compared to those who undergo cyst drainage. 8

Key Clinical Pearls

• Do not delay surgery waiting for complete loss of arterial flow — venous obstruction occurs first and is the more sensitive finding 1, 2
• Intermittent torsion can present with fluctuating symptoms and preserved flow on imaging, making diagnosis particularly challenging 1, 3
• Early surgical intervention prevents permanent ovarian damage and preserves fertility 2, 4
• The presence of an ovarian cyst or mass is a major risk factor, with mature cystic teratoma being the most common associated lesion 9