Adnexal torsion: Clinical sciences

Adnexal torsion occurs when the ovary and fallopian tube twist, either completely or partially, on their ligamentous support, causing obstruction of their blood supply. You may also see this process referred to as ovarian torsion, which occurs when the ovary twists on its supporting ligaments without involvement of the fallopian tube. On the other hand, the tube itself rarely rotates alone and instead often twists alongside the ovary.

As a little reminder, the ovary is suspended to the pelvic sidewall by the infundibulopelvic, or IP, ligament and to the uterus by the utero-ovarian ligament. Blood is supplied to the ovary from both the ovarian and uterine arteries. Now, if the ovary is enlarged, such as in the presence of a cyst, it may rotate on the axis of the two ligaments. Often, this occurs in ovaries measuring between 5 to 10 centimeters and occurs more frequently in the right adnexa, as the left adnexa has less space due to the presence of the sigmoid colon.

Adnexal torsion can cause edema, venous congestion, and compression of blood vessels. The venous supply is compromised first, and with time, the arterial supply might be affected too. Adnexal torsion is a surgical emergency and requires urgent reversal of the torsion to prevent necrosis and loss of the ovary.

When assessing a patient with a chief concern suggesting adnexal torsion, your first step is to perform a focused history and physical examination and obtain an hCG. The patient may report fever, nausea, and vomiting, as well as abdominal or pelvic pain. If pain is present, it is usually sudden, non-radiating, and intermittent in nature. On physical exam, you may note abdominal or pelvic tenderness, rebound pain or guarding, and possibly the presence of a pelvic mass. Lastly, hCG is typically negative.

Here’s a clinical pearl! While extremely rare, adnexal torsion can occur in a pregnant patient. The enlargement of the ovary due to the presence of the corpus luteum cyst and increased laxity of ligaments may contribute to the development of this rare condition.

Okay, back to our patient; after completing your focused history and physical, your next step is to order a pelvic ultrasound. Now, if the ultrasound shows symmetrical ovaries with normal adnexal position and size, you will consider an alternative diagnosis. With a negative hCG, ectopic pregnancy is already ruled out. However, the patient may have a ruptured ovarian cyst, a tubo-ovarian abscess, or appendicitis.

On the flip side, the ultrasound may reveal an asymmetrically enlarged ovary; with absent Doppler flow, where you might see the presence of twisted pedicle, or the whirlpool sign, which is significant for a thickened vascular pedicle of an enlarged ovary. If you see these findings, you should suspect adnexal torsion.

Now that you suspect adnexal torsion, your next step is to proceed with a diagnostic laparoscopy. Remember, this is a surgical emergency and every minute of compromised blood flow can impact the viability of the ovary! So, upon entry into the abdominal cavity, assess the adnexa for evidence of torsion. You may see no evidence of torsion with the adnexa appearing to be in a normal anatomical position. This indicates either the adnexa spontaneously detorsed or that you should consider an alternative diagnosis.