Ovarian Torsion Flashcards
What is the definition of ovarian torsion?
Complete or partial rotation of the ovary on its ligament outs supports, often resulting in impedance of its blood supply
What is the pathogenesis of ovarian torsion?
Ovarian typically rotates around both the IP and the utero-ovarian ligament
Rotation of the IP ligament causes compression of the ovarian vessels and impedes lymphatic and venous outflow and arterial inflow
The arterial supply to the ovary is not initially interrupted to the same degree as the venous drainage
- because the muscular arteries are LESS COMPRESSIBLE than the thin walls of the veins
- Continued arterial perfusion in the setting of blocked outflow leads to ovarian oedema with marked ovarian enlargement and further vascular compression
- Ovarian ischaemia then occurs, which can result in necrosis, infarction and local haemorrhage
What population(s) are more likely to get ovarian torsion without an ovarian mass (than the general population)
Pregnant women.
Paediatric < 15 years old; 50% torsion occurs with normal ovaries
Possibly due to elongation of the utero-ovarian ligament, which shortens as girls mature through puberty
Which ovary is more likely to torse?
Right ovary (2/3rds)
Mechanisms:
- Right utero-ovarian ligament is longer than the left
- Presence of the sigmoid colon on the left may help to prevent torsion.
What is the peak age of incidence of ovarian torsion
20s-30s
What % presentations with ovarian torsion will have an ovarian mass
86-95%
Particularly high risk if mass >5cm
How do premenarchal girls present with ovarian torsion?
Longer duration of symptoms before presentation
More likely to present with DIFFUSE pain, fever, restlessness
What are USS findings suggestive of ovarian torsion? (7)
- Ovary rounded and enlarged from oedema and vascular + lymph engorgement
- Heterogenous appearance of ovarian stroma due to oedema and haemorrhage
- Multiple small peripheral follicles, “string of pearls” also seen with PCOS, thought to be due to displacement by oedema
- Abnormal (midline) ovarian location
- Decreased or absent Doppler flow within the ovary
- Doppler greyscale WHIRLPOOL sign in the ovarian vessels
- round, hyperechoic structure with concentric hypoechoic stripes or a tubular structure with internal heterogenous echoes.
- thought to represent the twisting of the vascular pedicure - Ovarian mass / cyst
What is the role of oophoropexy in ovarian torsion?
No high quality data
Not recommended
Potentially helpful for children who torse without a mass
What are the risk factors for ovarian torsion?
- Ovarian mass >5 cm; dermoids.
- ART: theca lutein cysts, expanded ovarian volume.
- Pregnancy (5x): corpus luteal cyst, laxity; risk greatest 1st trimester.
- Congenital: excessively long tube or absent mesosalpinx.
- Previous pelvis surgery esp TL. Mechanism unknown.
What are signs of a necrotic ovarian torsion intra-operatively?
- Loss of normal anatomical structure
- Gelatinous or poorly defined structure.
Outline you approach to management of a suspected ovarian torsion
- Timeliness
- Laparoscopically ideally unless suspicion of malignancy.
- Most ovaries should be considered viable.
- Detort ovary.
- Cystectomy if associated cyst to reduce risk of future torsion.
- Consider oophoropexy to uterosacral ligament or shortening utero-ovarian ligament if child/adolescent with normal ovary.
When would you perform a salpingo-oophorectomy for an ovarian torsion?
- Necrotic or no viable tissue
- Suspicious for malignancy
- Postmenopausal
What follow-up would you organise following conservative management of a torsion?
- Follow-up pelvic USS 6 weeks.
- Consider ovarian cyst suppression with hormonal contraception to reduce risk of recurrence.
