eMedicine Specialties > Emergency Medicine > Obstetrics & Gynecology

Ovarian Torsion

Author: Erik D Schraga, MD, Consulting Staff, Department of Emergency Medicine, Mills-Peninsula Emergency Medical Associates; Consulting Staff, Permanente Medical Group, Kaiser Permanente, Santa Clara Medical Center
Coauthor(s): Michelle Blanda, MD, Chair, Department of Emergency Medicine, Summa Health System; Professor of Emergency Medicine, Northeastern Ohio Universities College of Medicine
Contributor Information and Disclosures

Updated: Aug 4, 2008

Introduction

Background

Ovarian torsion (adnexal torsion) is an infrequent but significant cause of acute lower abdominal pain in women. The clinical presentation is often nonspecific with few distinctive physical findings, commonly resulting in delay in diagnosis and surgical management.

Pathophysiology

Ovarian torsion classically occurs unilaterally in a pathologically enlarged ovary. The irregularity of the ovary likely creates a fulcrum around which the oviduct revolves. The process can involve the ovary alone but more commonly affects both the ovary and the oviduct (adnexal torsion). Approximately 60% of torsion occurs on the right side.

Multiple factors have been found to be responsible for the development of ovarian torsion. Although torsion may rarely occur in normal adnexa, it more frequently arises from one of many anatomic changes. Torsion of a normal ovary is most common among young children, in whom developmental abnormalities such as excessively long fallopian tubes or absent mesosalpinx may be responsible. In fact, less than half of torsed ovaries in pediatric patients involve cysts, teratomas, or other masses. During early pregnancy, the presence of an enlarged corpus luteum cyst likely predisposes the ovary to torsion. Women undergoing induction of ovulation for infertility carry an even greater risk, as numerous theca lutein cysts significantly expand the ovarian volume.

Ovarian tumors, both benign and malignant, are implicated in 50-60% of cases of torsion. Involved masses are nearly all greater than 4-6 cm, although torsion is possible with smaller masses.

Frequency

United States

Studies reveal that ovarian torsion is the fifth most common gynecologic surgical emergency accounting for 2.7% of cases of acute gynecologic complaints in one series.

International

Ovarian torsion is encountered more often in women who have had ovarian stimulation, which likely accounts for a small increased incidence in developed countries.

Mortality/Morbidity

Most patients with ovarian torsion have a delayed diagnosis, often resulting in infarction and necrosis of the ovary. The ovarian salvage rate has been reported below 10% in adults but as high as 27% in a study among pediatric patients¹ . Although it is unlikely that the loss of a single ovary results in significantly reduced fertility and no cases of death have been reported due to ovarian torsion, early diagnosis allows for conservative laparoscopic treatment and reduction in complications.

Sex

Ovarian torsion applies strictly to the female sex.

Age

Ovarian torsion can occur at any age, but most cases occur in the early reproductive years. Approximately 17% of cases have been found to occur in premenarchal or postmenopausal women.

• The median age reported by one large review was 28 years.
• The percentage of patients younger than 30 years is approximately 70-75%.

Clinical

History

• Classically, patients present with sudden onset, severe, unilateral lower abdominal pain that worsens intermittently over many hours. A minority of patients, however, complain of mild pain that follows a more prolonged time course. The pain usually is localized over the involved side, often radiating to the back, pelvis, or thigh. Approximately 25% of patients experience bilateral lower quadrant pain. It may be described as sharp and stabbing or less frequently crampy.
• Nausea and vomiting occur in approximately 70% of patients, mimicking a gastrointestinal source of pain and further obscuring the diagnosis.
• History of prior episodes may be elicited possibly due to partial, spontaneously resolving torsion.
• Fever may occur as a late finding as the ovary becomes necrotic.
• Onset during exercise or other agitating movement is common.

Physical

The physical examination, like the history, is typically nonspecific and is highly variable.

• A unilateral, tender adnexal mass has been reported in between 50 and 90% of patients. However, absence of such a finding does not exclude the diagnosis.
• Tenderness to palpation is common; however, it is mild in approximately 30% and absent in another 30% of patients. Therefore, the absence of tenderness cannot be used to rule out torsion.
• Peritoneal findings are infrequent and indicate advanced disease if present.

Causes

• Anatomic changes affecting the weight and the size of the ovary may alter the position of the fallopian tube and allow twisting to occur.
• Pregnancy is occasionally responsible for torsion, likely secondary to ovarian enlargement that occurs during ovulation in combination with laxity of the supporting tissues of the ovary.
• Congenitally malformed and elongated fallopian tubes may be seen particularly in young, prepubertal patients.
• Ovarian tumors result in over half of cases of adnexal torsion.
  • Dermoid tumors are most common.
  • Malignant tumors are much less likely to result in torsion than benign tumors. This is due to the presence of cancerous adhesions that fix the ovary to surrounding tissues.
• Conversely, patients with a history of pelvic surgery (principally tubal ligation) have an increased risk of torsion, likely owing to adhesions providing a site around which the ovarian pedicle may twist.

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