From the Guidelines
Ovarian torsion is a condition where the ovary twists around its supporting ligaments, cutting off its blood supply, and its pathophysiology involves a complex sequence of events including venous and lymphatic obstruction, arterial compromise, and ultimately tissue necrosis if not treated promptly. The pathophysiology begins with partial or complete rotation of the ovarian pedicle, which contains the ovarian vessels and fallopian tube, as reported in a study published in the Journal of the American College of Radiology 1. This rotation obstructs venous outflow while arterial inflow initially continues, leading to congestion, edema, and enlargement of the ovary. Several factors predispose to torsion, including ovarian masses (particularly those 5-10 cm in size), ovarian hypermobility, elongated ovarian ligaments, and sudden changes in body position.
Some key points to consider in the pathophysiology of ovarian torsion include:
- The right ovary is more commonly affected due to the greater length of the right utero-ovarian ligament and the presence of the sigmoid colon on the left side, which provides additional support.
- Hormonal stimulation during pregnancy or fertility treatments can increase the risk by enlarging the ovaries, as discussed in a study published in the American Journal of Obstetrics and Gynecology 1.
- The pathophysiological progression follows a time-dependent sequence: venous and lymphatic obstruction occurs first (within hours), followed by arterial compromise, and ultimately tissue necrosis if blood flow is not restored within approximately 36-48 hours.
- Timely diagnosis and surgical intervention are critical to preserve ovarian function, and a high index of suspicion for torsion must be maintained for patients with adnexal masses and acute lower abdominal pain, as 38% to 60% of patients with torsion have normal Doppler flow on ultrasound 1.
The diagnosis of ovarian torsion can be made using ultrasound, which has a reported sensitivity of 79% and a specificity of 76% for adnexal torsion, with negative and positive likelihood ratios of 0.29 and 4.35, respectively 1. The signs of ovarian torsion on US have varying accuracy, with the sensitivity and specificity being 21% and 100% for ovarian tissue edema, 52% and 91% for absence of intraovarian vascularity, 76% and 99% for absence of arterial flow, and 100% and 97% for absence or abnormal venous flow 1. Therefore, it is essential to consider the clinical presentation and ultrasound findings when diagnosing ovarian torsion, and to prioritize timely surgical intervention to prevent tissue necrosis and preserve ovarian function.
From the Research
Pathophysiology of Ovarian Torsion
The pathophysiology of ovarian torsion involves the twisting of the ovary and/or fallopian tube, leading to ischemic changes of the adnexa 2. This twisting can cause obstruction of the blood vessels, resulting in ischemia and potentially necrosis of the ovary 3, 4. The risk factors for ovarian torsion include ovarian cysts and prior pelvic surgery 4, as well as other conditions that can cause the ovary to become twisted.
Clinical Presentation
The clinical presentation of ovarian torsion typically includes severe, sharp, sudden onset of unilateral lower abdominal pain and tenderness, often accompanied by nausea and vomiting 3, 5, 2. A palpable laterouterine pelvic mass may also be present 3. The symptoms can be nonspecific, making diagnosis challenging 3.
Diagnostic Criteria
Diagnosis of ovarian torsion is often based on a combination of clinical presentation, imaging findings, and laboratory examinations 2. Pelvic ultrasonography can provide information on ovarian cysts and other adnexal masses 5, while computed tomography findings and plasma d-dimer level can help distinguish ovarian necrosis 2.
Surgical Procedures
Surgical management of ovarian torsion typically involves detorsion of the twisted ovary and/or fallopian tube, as well as removal of any underlying cause of the torsion, such as an ovarian cyst 3, 4, 6. In some cases, oophoropexy may be performed to prevent recurrent ovarian torsion, although the effectiveness of this procedure is controversial 2. Fertility-preserving management of ovarian torsion is possible, and laparoscopic management with detorsion and cystectomy can help preserve hormonal function and fertility in young women 6.
Key Points
- Ovarian torsion is a gynecological emergency that requires prompt diagnosis and treatment 3, 4, 2.
- The clinical presentation typically includes severe abdominal pain, nausea, and vomiting 3, 5, 2.
- Diagnosis is based on a combination of clinical presentation, imaging findings, and laboratory examinations 2.
- Surgical management involves detorsion of the twisted ovary and/or fallopian tube, as well as removal of any underlying cause of the torsion 3, 4, 6.