Ovarian torsion is like the MI of the pelvis. Sometimes all it takes is a good story to investigate.

When to worry, when to walk it off, and when to work it up:

What is the typical presentation of ovarian torsion?

There is none. The presentation varies so much, we need a rule to live by:

Unilateral pelvic pain in a girl is ovarian torsion until proven otherwise. This includes the cases in which you are concerned about appendicitis. They both can be fake-outs.

Often the pain is severe and abrupt, but trying to tease this out is often not fruitful.

Here are the often-reported signs and symptoms associated with ovarian torsion:

Stabbing pain, 70%

Nausea and vomiting, 70%

Sudden, sharp pain in the lower abdomen, 59%

Pain radiating to the back, flank, or groin, 51%

Peritoneal signs, 3%

Fever, less than 2%

And of course…no pain on presentation…30%...intermittent torsion.

What is the mechanism of ovarian torsion?

Structurally abnormal ovary (including cysts) that causes the ovary to flop over and twist on its vascular axis
Hypermobile ovary with vigorous movement twists on its vascular pedicle and cuts off blood supply

The Dual Blood Supply to the Ovaries: Why Doppler Flow can Fool You

What ultrasound findings suggest ovarian torsion?

The enlarged hyper or hypoechoic ovary from generalized edema
Peripherally displaced follicles with hyperechoic central stroma – this is called the string of pearls sign, because the stroma is edematous, leaving the follicles to stand out
A midline ovary – if the ovary magically makes it to midline, something is up
Free fluid in the pelvis – this is seen in the vast majority of cases

As far as Doppler flow goes, you may see one of several scenarios:

Little or no venous flow – this is very common, as we talked about, because the low pressure venous system is the first to take a hit in torsion
Totally absent arterial flow – this is not as common, but totally diagnostic
There may be no flow in diastole, or the flow may even be reversed. Rememver the red and blue of dopple does not correspond to arterial and venous. Doppler is a vector. Red is fluid coming towards the probe, blue is programmed to present flow away from the probe. If you have just one or the other, then by definition there is a problem with the vascular circuit.

Other things you may see on ultrasound include focal tenderness with the probe, or the whirlpool sign – this is a twisted vascular pedicle.

In children, is there an ovarian size (volume) that rules out torsion?"

In the Journal of Pediatric Radiology, Servaes et al catalogued the ultrasound findings in children with surgically confirmed torsion over a 12 year period. In this case series of 41 patients, the median age was 11. The age range was one month old to 21 years of age. They found that in torsed ovaries, the ovarian volume was 12 x that compared to the normal, non-torsed contralateral ovary.

That is to say, in this case series all torsed ovaries were larger than the normal contralateral ovary.

Summary

Sudden unilateral lower abdominal or pelvic pain in a female? Think torsion.

Have a low threshold for investigation.

Know the performance characteristics of ultrasound findings and involve a gynecologist early.

This post and podcast are dedicated to Stephanie Doniger, MD for her enthusiasm, spirit, and expertise in #MedEd #FOAMed #FOAMped #POCUS

References

Abe M, Sarihan H. Oophoropexy in children with ovarian torsion. Eur. J. Pediatr. Surg. 2004;14:168.

Aziz D, Davis V, Allen L, Langer J. Ovarian torsion in children: Is oophorectomy necessary? J. Pediatr. Surg. 2004;39:750-3.

Bristow RE, Nugent AC, Zahurak ML, et al. Impact of surgeon specialty on ovarian-conserving surgery in young females with an adnexal mass. J. Adolesc. Health 2006;39:411.

Chang YJ, Yan DC, Kong MS, et al. Adnexal torsion in children. Pediatr. Emerg. Care. 2008;24:534-7.

Conforti A, Giorlandino C, Bagolan P. Fetal ovarian cysts management and ovarian prognosis: a report of 82 cases. J. Pediatr. Surg. 2009;44:868; author reply 868-9.

Guthrie BD, Adler MD, Powell EC. Incidence and trends of pediatric ovarian torsion hospitalizations in the United States, 2000-2006. Pediatrics 2010;125:532-8. Epub 2010 Feb 1.

Houry D, Abbott JT. Ovarian torsion: a fifteen-year review. Ann. Emerg. Med. 2001;38:156-9.

Huang TY, Lau BH, Lin LW, Wang TL, Chong CF, Chen CC. Ovarian cyst torsion in a toddler. Am. J. Emerg. Med. 2009;27:632, e1-3.

Hurh PJ, Meyer JS, Shaaban A. Ultrasound of a torsed ovary: characteristic gray-scale appearance despite normal arterial and venous flow on Doppler. Pediatr. Radiol. 2002;32:586-8. Epub 2002 May 25.

Kokoska E, Keller M, Weber T. Acute ovarian torsion in children. Am. J. Surg. 2000;180:462-5.

Oltmann SC, Fischer A, Barber R, Huang R, Hicks B, Garcia N. Cannot exclude torsion – a 15-year review. J. Pediatr. Surg. 2009;44:1212-6; discussion 1217.

Chmitt ER et al. Twist and Shout! Pediatric Ovarian Torsion Clinical Update and Case Discussion. Pediatr Emerg Care. 2013; 29(4):518-523.

Servaes S, Zurakowski D, Laufer MR, Feins N, Chow JS. Sonographic findings of ovarian torsion in children. Pediatr. Radiol. 2007;37:446-51. Epub 2007 Mar 15.

Valsky DV. Added value of the gray-scale whirlpool sign in the diagnosis of adnexal torsion. Ultrasound Obstet. Gynecol. 2010;36:630-4.

Ovarian Torsion

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