Adnexal torsion is seen in approximately 2 -3 % of adolescents and young women in the reproductive age, though prepubertal and postmenopausal cases have also been reported. Ovarian torsion is defined as partial or complete rotation of the ovarian pedicle to such a degree as to occlude or compromise its vascular and lymphatic drainage. “Twisted ovarian cyst” presents as a medical emergency and may imply torsion of the ovary or adnexa; less commonly, paraovarian torsion or isolated torsion of only fallopian tube may be encountered.
Classic clinical features include sudden onset lower abdominal pain (right sided more common as the colon on the left is protective and does not give enough room for torsion to occur), nausea and vomiting. The pain may sometimes be colicky or episodic when the torsion is intermittent or partial. The commonest differential diagnosis is ectopic pregnancy; tubo- ovarian mass due to PID, acute appendicitis and renal colic should also be kept in mind. Ultrasonography is the diagnostic modality of choice, where commonly an enlarged ovary or ovarian cyst, and free fluid in the pelvis are seen. The “whirlpool sign” (twisted vascular pedicle) if seen, has a high sensitivity for diagnosing torsion. Though Doppler may reveal the absence of blood flow in the ovarian pedicle with high specificity, Doppler USG is not a sensitive modality and has not been found to improve the diagnostic accuracy. In fact, many surgically proven cases of torsion show the presence of blood flow on Doppler. CT scan and MRI should be reserved for those patients where the diagnosis is in doubt. Misdiagnosis and diagnostic delay can lead to the loss of the ovary, fallopian tube or both; prompt diagnosis is essential to reduce the risk of complications and increase the chances of ovarian conservation.
Ovarian masses associated with torsion are usually benign. A long utero- ovarian ligament rather than the size of the cyst determines whether torsion will occur. Torsion of the ovarian vascular pedicle results in venous congestion, hemorrhage, ischemia and eventually necrosis, believed to cause loss of ovarian function. It was for this reason that historically all torsed adnexae which appeared necrotic were surgically removed; emergency laparotomy with salpingo- oophorectomy was the standard treatment.
Laparoscopy has taken over from laparotomy in the last three decades and laparoscopic detorsion of the twisted adnexae with ovarian preservation is now the recommended surgical treatment, even in the presence of complete vascular occlusion or hemoperitoneum. Numerous studies in literature have evaluated laparotomy or laparoscopy with ovarian preservation with favorable results. Even if the ovary is dark, ischemic or necrotic in appearance, many authors emphasize that detorsion is the only surgery which should be performed; this is relatively easy and safe to do. As the tissue is extremely edematous and friable, care should be exercised; gentle handling and non –traumatic instruments should be used. The return of color after detorsion, and normal blood flow may not resume immediately but this should not discourage the surgeon. Surgeons usually excise necrotic tissue but the temptation to bivalve the ovary or perform cystectomy should be avoided as it can cause hemorrhage and undue removal of ovarian tissue as there is usually no clear plane of cleavage, eventually leading to oophorectomy. Though there are risks of sepsis (due to liberation of toxins), peritonitis and emboli, these are largely theoretical and have not been reported.
Oophoropexy, the surgical fixation or suspension of the ovary, is also easily performed via the laparoscope. It has previously been performed to prevent repeat ovarian torsion, and on the contra-lateral normal ovary to prevent torsion, but its efficacy is debatable and hence is not recommended. Current evidence has shown that ovarian function is preserved in as many as 88 - 100% of cases. Obviously, better outcomes are achieved if the surgical intervention occurs within 36 hours, with some reports suggesting that the best results are achieved when the time of onset of torsion to surgery is 8 hours. Many studies have analyzed subsequent ovarian follicular development, and shown restoration of ovarian function in > 80% of these ovaries. Laparotomy performed for unrelated causes has also shown macroscopically normal ovaries. In patients undergoing IVF treatment, oocytes have been retrieved from the previously detorsed ovaries and successfully fertilized. Hence preservation of ovarian function and fertility should be paramount and cases of twisted adnexae should be treated laparoscopically with detorsion and ovarian conservation. The September issue of our journal carries a case report on ovarian conservation in a case of adnexal torsion, which should interest and help the readers.