Ovarian torsion
Updates to Article Attributes
Ovarian torsion (also, also sometimes termedadnexal torsion) or tubo-ovarian torsion, refers to rotation of the ovary and portion of the fallopian tube on the supplying vascular pedicle (also termed tubo-ovarian torsion)
ThisIt can be be intermittent or sustained and results results in venous, arterial and lymphatic stasis. It is a gynaecologcialgynaecological emergency and requires requires urgent surgical intervention to prevent ovarian necrosis.
Epidemiology
Ovarian torsion has a bimodal age distribution occurring mainly in young women (15-30 years) and in post-menopausal women. Approximately 20% of the cases occur during pregnancy 1.
Torsion occurs for two main reasons 2:
- hypermobility of the ovary: <50%
- adnexal mass: ~50-80%
- most lesions are dermoid cysts or
paraovarianpara ovarian cysts - masses between 5-10 cm are at most risk 13
- most lesions are dermoid cysts or
Clinical presentation
Most patients present with severe nonspecific lower abdominal and pelvic pain, nausea, and vomiting. There is adnexal tenderness. A raised white cell count is common.
Presentation of torsion can be either intermittent or sustained.
Pathology
The end result of the vascular compromise of ovarian torsion is haemorrhagic infarction and necrosis. This that can occur within hours of torsion onset.
Torsion of a normal ovary more commonly occurs in young children when developmental abnormalities may be implicated in the pathogenesis, such as excessively long Fallopian tubes or an absent mesosalpinx.
In adulthood, causes include both benign and malignant ovarian tumours, polycystic ovaries and adhesions. In early pregnancy, a torsion can occur secondary secondary to a corpus luteum cyst or laxity of the adjacent tissues.
Radiographic features
The main main feature of torsion is ovarian enlargement due to venous/lymphatic engorgement, oedema and haemorrhage. Secondary signs include free pelvic fluid, an underlying ovarian lesion, reduced or absent vascularity and a twisted dilated tubular structure corresponding to the vascular pedicle. Adnexal torsion is generallycommonly unilateral, with a slight (3:2) right-sided predilection (presumably due to effects of the sigmoid colon being on the left) 6,8.
Ultrasound
Ultrasound is the imaging modality of choice. Sonographic features include:
- enlarged hypo
-or hyperechoic ovary - peripherally displaced follicles with hyperechoic central stroma
- midline ovary
- free pelvic fluid: may be seen in >80% of cases
- an underlying ovarian lesion may be seen (possible lead point for torsion)
- a long-standing infarcted ovary may have a more complex appearance with cystic or haemorrhagic
degenerationdegeneration
Doppler 3
- Doppler findings in torsion can be widely variable3
- little or no intra-ovarian venous flow (common)
- absent arterial flow (less common, but poor prognostic sign)
- absent or reversed diastolic flow
- normal vascularity does not exclude intermittent torsion
- normal Doppler flow can also occasionally be found
duedue to dual supply from both the ovarian and uterine arteries
- normal Doppler flow can also occasionally be found
- whirlpool sign of twisted vascular pedicle 3
The ovary should be tender to transducer pressure 13.
CT
- good at ruling out ovarian torsion if a normal ovary/adnexa is seen
- twisted ovarian pedicle is pathognomonic for ovarian torsion if demonstrated 11
- torsion appears as a complex adnexal lesion representing
:- enlarged ovary (>4.0 cm 11)
- distended pedicle
- possible underlying ovarian lesion
- HU >50 on non-contrast CT suggests haemorrhagic necrosis 2
- lack of enhancement may be seen
- surrounding fat stranding, oedema, and free fluid
Pelvic MRI
Not the imaging modality of choice if torsion is suspected, as urgent imaging is required.
If haemorrhagic infarction is present, signal changes include4:
-
T1
- thin rim of high signal (methaemoglobin) without contrast enhancement
-
endometriomas and haemorrhagic corpus luteal cysts are less likely to have
higha high T1 rim and do not usually involve the entire ovary
-
T2: can have low signal
duedue tointerstitialinterstitial haemorrhage
Treatment and prognosis
Urgent surgery is required to prevent ovarian necrosis. Most ovaries are not salvageable in which case a salpingo-oophorectomy is required. If not removed the necrotic ovary can become infected and cause abscess or peritonitis. In the case of a non-infarcted adnexa, surgical untwisting can be performed. Mortality resulting from ovarian torsion is rare. Spontaneous de-torsion has also been reported.
Differential diagnosis
For an enlarged oedematous ovary +/- Fallopian tube, consider:
-
pelvic inflammatory disease (PID): has a
veryvery different clinical presentation - massive ovarian oedema (MOO)
- oophoritis
Practical points
- the ovary should be tender to transducer pressure
- absence of ovarian Doppler flow is highly specific for torsion, but
normal Dopplernormal Doppler flow does not completely exclude torsion - an ovarian mass causing the torsion must always be sought
-<p><strong>Ovarian torsion</strong> (also sometimes termed <a href="/articles/adnexal-torsion">adnexal torsion</a>) refers to rotation of the ovary and portion of the fallopian tube on the supplying vascular pedicle (also termed <strong>tubo-ovarian torsion</strong>). </p><p>This can be intermittent or sustained and results in venous, arterial and lymphatic stasis. It is a gynaecologcial emergency and requires urgent surgical intervention to prevent ovarian necrosis. </p><h4>Epidemiology</h4><p>Ovarian torsion has a bimodal age distribution occurring mainly in young women (15-30 years) and in post-menopausal women. Approximately 20% of the cases occur during pregnancy <sup>1</sup>.</p><p>Torsion occurs for two main reasons <sup>2</sup>: </p><ul>- +<p><strong>Ovarian torsion</strong>, also sometimes termed <a href="/articles/adnexal-torsion">adnexal torsion</a> or tubo-ovarian torsion, refers to rotation of the ovary and portion of the fallopian tube on the supplying vascular pedicle. </p><p>It can be intermittent or sustained and results in venous, arterial and lymphatic stasis. It is a gynaecological emergency and requires urgent surgical intervention to prevent ovarian necrosis. </p><h4>Epidemiology</h4><p>Ovarian torsion has a bimodal age distribution occurring mainly in young women (15-30 years) and post-menopausal women. Approximately 20% of the cases occur during pregnancy <sup>1</sup>.</p><p>Torsion occurs for two main reasons <sup>2</sup>: </p><ul>
-<li>most lesions are <a href="/articles/mature-cystic-ovarian-teratoma">dermoid cysts</a> or <a href="/articles/paraovarian-cyst-1">paraovarian cysts</a>- +<li>most lesions are <a href="/articles/mature-cystic-ovarian-teratoma">dermoid cysts</a> or <a href="/articles/paraovarian-cyst-1">para ovarian cysts</a>
-</ul><h4>Clinical presentation</h4><p>Most patients present with severe nonspecific lower abdominal and pelvic pain, nausea, and vomiting. There is adnexal tenderness. A raised white cell count is common.</p><p>Presentation of torsion can be either intermittent or sustained.</p><h4>Pathology</h4><p>The end result of the vascular compromise of ovarian torsion is haemorrhagic infarction and necrosis. This can occur within hours of torsion onset. </p><p>Torsion of a normal ovary more commonly occurs in young children when developmental abnormalities may be implicated in the pathogenesis, such as excessively long Fallopian tubes or an absent mesosalpinx.</p><p>In adulthood, causes include both benign and malignant ovarian tumours, polycystic ovaries and adhesions. In early pregnancy a torsion can occur secondary to a corpus luteum cyst or laxity of the adjacent tissues.</p><h4>Radiographic features</h4><p>The main feature of torsion is ovarian enlargement due to venous/lymphatic engorgement, oedema and haemorrhage. Secondary signs include free pelvic fluid, an underlying ovarian lesion, reduced or absent vascularity and a twisted dilated tubular structure corresponding to the vascular pedicle. Adnexal torsion is generally unilateral, with a slight (3:2) right-sided predilection (presumably due to effects of the sigmoid colon being on the left) <sup>6,8</sup>.</p><h5>Ultrasound</h5><p>Ultrasound is the imaging modality of choice. Sonographic features include:</p><ul>-<li>enlarged hypo- or hyperechoic ovary</li>- +</ul><h4>Clinical presentation</h4><p>Most patients present with severe nonspecific lower abdominal and pelvic pain, nausea, and vomiting. There is adnexal tenderness. A raised white cell count is common.</p><p>Presentation of torsion can be either intermittent or sustained.</p><h4>Pathology</h4><p>The result of the vascular compromise of ovarian torsion is haemorrhagic infarction and necrosis that can occur within hours of torsion onset. </p><p>Torsion of a normal ovary more commonly occurs in young children when developmental abnormalities may be implicated in the pathogenesis, such as excessively long Fallopian tubes or an absent mesosalpinx.</p><p>In adulthood, causes include both benign and malignant ovarian tumours, polycystic ovaries and adhesions. In early pregnancy, a torsion can occur secondary to a corpus luteum cyst or laxity of the adjacent tissues.</p><h4>Radiographic features</h4><p>The main feature of torsion is ovarian enlargement due to venous/lymphatic engorgement, oedema and haemorrhage. Secondary signs include free pelvic fluid, an underlying ovarian lesion, reduced or absent vascularity and a twisted dilated tubular structure corresponding to the vascular pedicle. Adnexal torsion is commonly unilateral, with a slight (3:2) right-sided predilection (presumably due to effects of the sigmoid colon being on the left) <sup>6,8</sup>.</p><h5>Ultrasound</h5><p>Ultrasound is the imaging modality of choice. Sonographic features include:</p><ul>
- +<li>enlarged hypo or hyperechoic ovary</li>
-<li>a long-standing infarcted ovary may have a more complex appearance with cystic or haemorrhagic degeneration</li>-</ul><h6>Doppler <sup>3</sup>-</h6><ul>-<li>Doppler findings in torsion can be widely variable<ul>- +<li>a long-standing infarcted ovary may have a more complex appearance with cystic or haemorrhagic degeneration</li>
- +<li>Doppler findings in torsion can be widely variable<sup>3</sup><ul>
-<li>normal vascularity does not exclude intermittent torsion<ul><li>normal Doppler flow can also occasionally be found due to dual supply from both the ovarian and uterine arteries</li></ul>- +<li>normal vascularity does not exclude intermittent torsion<ul><li>normal Doppler flow can also occasionally be found due to dual supply from both the ovarian and uterine arteries</li></ul>
-<li>torsion appears as a complex adnexal lesion representing:<ul>- +<li>torsion appears as a complex adnexal lesion representing<ul>
-</ul><h5>Pelvic MRI</h5><p>Not the imaging modality of choice if torsion is suspected, as urgent imaging is required.</p><p>If haemorrhagic infarction is present, signal changes include <sup>4</sup>:</p><ul>- +</ul><h5>MRI</h5><p>Not the imaging modality of choice if torsion is suspected, as urgent imaging is required.</p><p>If haemorrhagic infarction is present, signal changes include <sup>4</sup>:</p><ul>
-<a href="/articles/endometriosis">endometriomas</a> and haemorrhagic corpus luteal cysts are less likely to have high T1 rim and do not usually involve the entire ovary</li>- +<a href="/articles/endometriosis">endometriomas</a> and haemorrhagic corpus luteal cysts are less likely to have a high T1 rim and do not usually involve the entire ovary</li>
-<strong>T2:</strong> can have low signal due to interstitial haemorrhage</li>- +<strong>T2:</strong> can have low signal due to interstitial haemorrhage</li>
-<a href="/articles/pelvic-inflammatory-disease-pid">pelvic inflammatory disease (PID)</a>: has a very different clinical presentation</li>- +<a href="/articles/pelvic-inflammatory-disease-pid">pelvic inflammatory disease (PID)</a>: has a very different clinical presentation</li>
-<li>absence of ovarian Doppler flow is highly specific for torsion, but normal Doppler flow does not completely exclude torsion</li>- +<li>absence of ovarian Doppler flow is highly specific for torsion, but normal Doppler flow does not completely exclude torsion</li>
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