A Case of Adnexial Torsion During Pregnancy: Shortcomings in Doppler Ultrasonography

Abstract

Turkish Abstract

Introduction

Adnexal torsion is defined as the rotation of the adnexa around the line of the tuboovarian ligament and the infindibulopelvic ligament that resulted in obstruction of blood flow and it is a gynecologic emergency.  But, adnexal torsion in pregnancy is a rare event, with an incidence of  1-5:10.000 in spontaneous pregnancies. This incidence rises after controlled ovarian stimulation. ¹ The early diagnosis is important because delay can lead to irreversible complications such as loss of the adnexa. However, delays in diagnosis and surgical intervention are relatively common due to non-specific presentation of cases and overlapping of sign-symptoms of gastrointestinal and gynecologic pathologies. ^1-5

Previous studies have shown that only 23 % to 66 % of cases are given the correct presurgical diagnosis. ^1,3 Although ultrasonography (US) is the primary imaging modality for evaluation of ovarian torsion, findings sometimes inconclusive. ^2,4 For this reason the knowledge of clinicians about pitfalls in diagnostic procedures, gray scale and Doppler ultrasonographic evaluations before complete infarction of the ovary is important. The presented case was adnexal torsion after IVF pregnancy. The shortcomings in the diagnosis and management  of pregnancies were discussed.

Case Report

A 24-year-old woman presented to the emergency department (ED) of public hospital 3 hours after the abrupt onset of right lower quadrant abdominal pain. She had 9 weeks of IVF pregnancy with controlled ovarian stimulation. She described the severe abdominal  pain associated with nausea and vomiting. Similar episodes of pain and vomiting were experienced in the previous  week. These were, however, shorter in duration and resolved spontaneously. There was no vaginal bleeding or bowel symptoms. The laboratory findings; complete blood count, hepatic enzymes, hematocrite and urine analysis were normal. The differential diagnosis of lower abdominal pain such as acute appendicitis, necrotic degeneration of myoma, renal colic was done via ultrasonography.

Transvaginal ultrasonographic examination showed an enlarged (7.0 × 7.5 cm) right ovary with heterogenous appearance, a small amount of fluid was revealed in the pouch of Douglas (Figure 1).

Figure 1 Gray scale ultrasonographic view of the right ovary.

A vaginal ultrasound scan revealed a single 9- week- CRL corresponding to a fetus with regular heart rate at 170/min (Figure 2).

Figure 2 Nine weeks of fetus with fetal cardiac activity.

After that, she was referred to tertiary center with suspicion of adnexal torsion. She was hospitalized in Kocaeli University Medical Faculty, Gynecology and Obstetrics Department, with the suspicion of adnexal torsion. The Color Doppler examination showed both ovarian and intraovarian blood flow (Class I) . Her symptoms subsided and management was done conservatively. Daily gray scale and color Doppler ultrasonography was done. There were no symptoms other than hyperemesis gravidarum. Two days later, she had again an episode of pelvic pain. She underwent Doppler ultrasonography and there was no blood flow in the right ovary (Class III) . An emergency laparoscopy was done, surgical findings showed the enlarged cystic ovary was a bluish bulk large and measured about 7 cm in diameter that was three times twisted. The underwinding the twisted ovary was tried, however recoloration of adnexia was not detected. Due to gangrenous appearance of the adnexa, right salpingo-oopherectomy was performed. Surgeons did not want to run the risk of re-operation by allowing gangrenous ovary during pregnancy. The pathological findings confirmed the hemorrhagic necrosis. Postoperative period and antenal visits was uneventful, she delivered a healthy  baby at term.

Discussion

Doppler ultrasonography is highly specific  for the adnexal torsion, but it is not a sensitive test. ^2,4  Arterial blood flow may be seen in adnexal torsion cases, leading to false-negative results. The presence of flow does not exclude the torsion,  instead suggest the viability of the ovary. Since torsion may be intermittent or one of the arteries twisted (uterine or ovarian) or firstly venous thrombosis occur, blood flow may observe in Doppler findings. ^2,4  The interpretation of Doppler results of adnexal torsion is variable in studies and most of them does not focus on. ⁶ The previous study compared the adnexal torsion cases of pregnancies with  nonpregnant women, and found  normal blood flow in 61 % of pregnancies  and 45 % of nonpregnant women with adnexal torsion. ⁶

Ovarian arterial and venous blood flow are classified byAuslender. ⁷  This classification may be a useful guide for both diagnosis and clinical management.  Class I: Both arterial and venous blood flow to the ovary is found and the conservative approach may be considered, if the clinical condition of the patient is suitable.  Spontaneous resolution  may take place by detorsion spontaneously. Class II: Venous flow is absent, but arterial flow preserved. This time spontaneous resolution is not seen Class III: both arterial and venous blood flow absent and  ischemia exist. In patients with diagnosis of class II and III Doppler ultrasonographic findings, emergent surgical approach is needed. ⁷  The diagnostic and therapeutic  algorithm of adnexal torsion in pregnancy was given in Table 1.

In our case, both arterial and venous flow were normal, the patient's symptoms subsided. Probably due to twist-untwist attacks. Sometimes as in this case incomplete torsion may occur due to uterus limit movements of ovary. However, close monitoring showed worsening of symptoms and disappearance of both arterial and venous blood flow. This case suggested us, repeated attacks of semitorsion  may endanger ovarian tissue perfusion. Elective laparoscopy should be planned, if torsion-detorsion attacks occur in Class I cases.  Laparoscopy may be used safely in pregnancies with suspected adnexal torsion. Todays, detorsion or detorsion and pexy in pregnant woman were recommended, owing to the advantages of laparoscopy as shorter hospital stay and favorable outcomes. Salphingo-oopherectomy is the last choice as in this case, if ischemia has already settled. ^8,9,10,12

Conclusion

If pregnant women with ovarian stimulation history, present the emergency department with acute abdominal signs and symptoms, always keep in mind the risk of ovarian torsion. Loss of fertility depends on early diagnosis and prompt management. Ultrasonography is the primary imaging modality for ovarian torsion. Although the Doppler classification of ovarian torsion is useful in Class II and III cases, the presence of normal Doppler findings should not overweight clinical suspicion.

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