Ovarian torsion

Background

• Rotation of the ovary around its vascular pedicle (infundibulopelvic and utero-ovarian ligaments)
• Compromises venous/lymphatic drainage first → edema → eventual arterial compromise → ischemia and necrosis
• 5th most common gynecologic emergency
• Accounts for ~3% of all gynecologic emergencies
• Most common in reproductive-age women (20-40 years)
• Risk factors:
  • Ovarian mass >5 cm (most common risk factor; dermoid cysts particularly prone)
  • Ovarian hyperstimulation syndrome (fertility treatment)
  • Pregnancy (especially first trimester; corpus luteum cysts)
  • Prior tubal ligation (increases ovarian mobility)
  • Long utero-ovarian ligament
• Right side more common than left (sigmoid colon may limit left ovarian mobility)
• Can occur in prepubertal girls (often without predisposing mass — normal ovary)

Clinical Features

• Sudden onset, severe, unilateral lower abdominal/pelvic pain (most common presentation)
• Pain may be intermittent (intermittent torsion/detorsion)
• Nausea and vomiting (present in 70% — may be prominent)
• Low-grade fever (late finding suggesting necrosis)
• Adnexal tenderness on bimanual exam; palpable adnexal mass in ~50%
• May mimic appendicitis, renal colic, or ectopic pregnancy
• Peritoneal signs are late and suggest necrosis
• In children: may present with non-specific abdominal pain

Differential Diagnosis

• Ectopic pregnancy (always obtain pregnancy test first)
• Ruptured ovarian cyst
• Appendicitis
• Renal colic / nephrolithiasis
• Pelvic inflammatory disease / tubo-ovarian abscess
• Endometriosis
• Testicular torsion (analogous condition)
• Hemorrhagic corpus luteum

Acute Pelvic Pain

Differential diagnosis of acute pelvic pain

Gynecologic/Obstetric

• Normal variants may be noted on exam but generally do not cause pain or other symptoms
  • Nabothian cysts: Epithelial cells within mucous glans that appear as yellow inclusions on the cervix
  • Cervical Ectropion: Edothelial cells on the exterior of the cervix
  • Parous cervix: The is no longer round but may have multiple shapes after birth
• Pregnancy-related
  • Ectopic pregnancy
  • Spontaneous abortion, threatened or incomplete
  • Septic abortion
• Pelvic organ prolapse
• Acute Infections
  • Herpes
  • Cervicitis
  • Endometritis
  • Bartholin gland abscess
  • Pelvic inflammatory disease (PID)
  • Tubo-ovarian abscess
• Vulvovaginitis
  • Bacterial Vaginosis
  • Candida Vaginitis
  • Trichomonas
  • Contact Vulvovaginitis
  • Atrophic vaginitis
• Adnexal Disorders
  • Hemorrhage/rupture of ovarian cyst
  • Ovarian torsion
  • Twisted paraovarian cyst
• Other
  • Myoma (degenerating)
  • Genitourinary trauma
  • Ovarian hyperstimulation syndrome
  • Sexual assault
• Recurrent
  • Mittelschmerz
  • Primary/Secondary Dysmenorrhea
  • Pelvic Congestion Syndrome
  • Endometriosis

Genitourinary

• Cystitis
• Pyelonephritis
• Urethritis (e.g. N. gonorrhoeae/Chlamydia)
• Urolithiasis

Gastrointestinal

• Gastroenteritis
• Appendicitis
• Bowel obstruction
• Perirectal abscess
• Diverticulitis
• Inflammatory bowel disease
• Irritable bowel syndrome
• Mesenteric adenitis

Musculoskeletal

• Abdominal wall hematoma
• Psoas hematoma, psoas abscess
• Hernia

Vascular

• Pelvic thrombophlebitis
• Abdominal aortic aneurysm
• Ischemic bowel (Mesenteric Ischemia)

Evaluation

• Urine pregnancy test (rule out ectopic pregnancy)
• CBC: leukocytosis may be present (nonspecific)
• Urinalysis: rule out UTI, nephrolithiasis
• Lactate: may be elevated in late presentations

Transvaginal Ultrasound (Test of Choice)

• Enlarged ovary (>4 cm) compared to contralateral side
• Ovarian edema (heterogeneous appearance)
• Peripherally displaced follicles ("string of pearls" sign)
• Whirlpool sign on Doppler: twisted vascular pedicle (most specific finding)
• Free fluid in cul-de-sac

Doppler Findings

• Absent or decreased ovarian arterial/venous flow supports diagnosis
• HOWEVER: presence of Doppler flow does NOT exclude torsion
  • Sensitivity of absent flow is only ~50% — dual blood supply (ovarian and uterine arteries)
  • Intermittent torsion may show normal flow between episodes
• If high clinical suspicion, proceed to OR despite normal Doppler

CT Abdomen/Pelvis

• May show enlarged ovary, fat stranding, deviation of uterus toward affected side
• Less sensitive than US for torsion but may identify alternative diagnoses
• "Ovarian mass with surrounding fat stranding" on CT should raise concern

Management

• Emergent gynecology consultation for operative intervention
• Time-sensitive — ovarian salvage rates decrease with prolonged ischemia
  • Detorsion within 6 hours: high salvage rate
  • Detorsion at 24-36 hours: viable ovary still possible
  • Do not assume a black/dusky ovary is nonviable — most recover after detorsion
• Laparoscopic detorsion is procedure of choice (preserves fertility)
• Oophoropexy (fixation) may be performed to prevent recurrence
• Oophorectomy reserved for clearly necrotic tissue or suspected malignancy
• Supportive care in ED:
  • IV fluids, antiemetics (ondansetron 4 mg IV)
  • Pain control: ketorolac 15-30 mg IV and/or opioids
  • NPO for OR preparation

Disposition

• Admit for emergent surgical intervention
• Do NOT delay surgery for additional imaging if clinical suspicion is high
• Consult gynecology early — even if US is equivocal, operative evaluation may be warranted

See Also

• Ovarian cyst
• Ectopic pregnancy
• Testicular torsion
• Pelvic pain
• Appendicitis

References

• Huchon C, Fauconnier A. Adnexal torsion: a literature review. Eur J Obstet Gynecol Reprod Biol. 2010;150(1):8-12. PMID 20189289
• Chang HC, et al. Pearls and pitfalls in diagnosis of ovarian torsion. Radiographics. 2008;28(5):1355-1368. PMID 18794312
• Houry D, Abbott JT. Ovarian torsion: a fifteen-year review. Ann Emerg Med. 2001;38(2):156-159. PMID 11468611
• Oelsner G, Shashar D. Adnexal torsion. Clin Obstet Gynecol. 2006;49(3):459-463. PMID 16885652