Clinical indices and histological changes over time in ovarian torsion related to ovarian tumors
In some emergency surgeries for ovarian torsion, the ovary cannot be conserved because of necrosis. Ovarian necrosis and the time from the onset of symptoms to surgery are likely to be directly correlated. In this study, we retrospectively evaluated the clinical indices from the time of onset of acute abdomen to surgery at our hospital, in patients with tumor-related ovarian torsion. Among cases diagnosed preoperatively with benign ovarian tumors between 1995 and 2010, there were 54 patients who developed acute abdomen that was surgically diagnosed as ovarian torsion. For evaluation, these patients were divided into two groups according to the time from the onset of acute abdomen to surgical intervention as follows: <10 and ≥10 h. C-reactive protein (CRP) levels, leukocyte counts, body temperature, tumor size, and degree of torsion were compared between the two patient groups. Ovarian status based on postoperative histopathology was classified as necrotic, congestive, or normal, and was also evaluated. The mean CRP level was significantly higher in the ≥10-h patient group than in the patients undergoing surgery in <10 h. No differences were observed between the two groups for leukocyte counts, body temperature, tumor size, and mean degree of torsion. Ovarian necrosis was only observed only in patients undergoing surgery at ≥10 h. When tumor-related ovarian torsion is suspected, surgery should be performed within 10 h after the onset of acute abdomen to conserve ovarian function.
KeywordsOvarian tumor Acute abdomen Torsion Emergency surgery Necrosis
Ovarian tumor is one of the most common gynecological diseases. Among complications of ovarian tumors, ovarian torsion causes acute abdomen and is an indication for emergency surgery. Torsion has been reported to occur in 6.9–11% of ovarian tumor patients [1, 2]. In general, when ovarian torsion develops, venous blood flow to the ovary is first blocked, followed by abrupt onset of abdominal pain, and then, the arterial blood flow is blocked, then in some cases the ovary becomes necrotic  over time. In addition, ovarian tumors can rupture in some patients, resulting in peritonitis and even disseminated intravascular coagulation (DIC) . In the event of necrosis, sometimes the ovary cannot be conserved and oophorectomy is required, and in other cases, even if the ovary can be conserved, ovarian function is lost. However, Mashiach et al.  have shown that black-blue ovaries can be preserved with no damage, maintaining future ovarian function. From the aspect of fertility, it is especially important to preserve ovarian function in pubescent and sexually mature patients with torsion.
Mazouni et al. reported that necrosis was significantly more frequently observed in patients undergoing surgery more than 10 h from the onset of abdominal pain . However, there has been no definitive report on the relationship between the time to surgery and ovarian function in tumor-related ovarian torsion. In this study, we retrospectively examined patients with tumor related ovarian torsion who had undergone surgery at our hospital, and evaluated their clinical indices from the time of onset of acute abdomen until surgery.
There were 1,723 patients (1,224 laparoscopies and 499 laparotomies) who were preoperatively diagnosed with benign ovarian tumor and underwent surgery at our hospital from January 1995 to December 2010. Among these, there were 54 patients (25 laparoscopies and 29 laparotomies, 29 adnexectomies and 25 ovarian tumorectomies) who underwent surgery because of acute abdomen and who were diagnosed with tumor-related ovarian torsion based on the intraoperative findings.
These patients were divided into the following two groups according to the time from the onset of acute abdomen to surgery: <10 and ≥10 h until surgery. C-reactive protein (CRP) levels (upper limit of normal, ≤0.3 mg/dl), leukocyte counts (reference range, 3.5–8.5 × 103/μl), body temperature, tumor size, and degree of torsion were compared between the two groups. The degree of torsion was estimated at 90° intervals intraoperatively. Blood samples and body temperatures were obtained approximately 1 h before surgery.
For statistical analysis, the Student t-test was used to evaluate comparisons between the two groups. P values <0.05 were considered statistically significant.
Comparisons of data on the two groups of patients classified by time to surgery
Overall (n = 54)
Time <10 h (n = 20)
Time ≥10 h (n = 34)
1.1 ± 2.9 (0–2.9)
0.1 ± 0.3 (0–1.4)
1.7 ± 3.6 (0–12.9)
10.1 ± 3.1 (3.2–17.3)
10.1 ± 2.8 (4.7–13.4)
10.0 ± 3.2 (4.2–17.3)
36.9 ± 0.7 (35.9–38.7)
36.7 ± 0.5 35.9–37.7)
37.1 ± 0.7 (35.6–38.7)
Tumor diameter (cm)
9.1 ± 3.3 (3.6–20.0)
8.3 ± 2.8 (4.5–15.0)
9.5 ± 3.6 (3.6–20.0)
Degree of torsion (°)
607 ± 309 (120–1260)
506 ± 258 (120–900)
667 ± 325 (180–1,260)
Number of cases according to histopathological status in the two groups of patients classified by time to surgery
<10 h (range)
≥10 h (range)
10 (3–9 h)
9 (10–31 h)
10 (4–6 h)
12 (10–27 h)
13 (10–264 h)
Preoperative diagnosis of ovarian torsion caused by ovarian tumor is difficult, and the condition must be differentiated from other emergent gynecological diseases that present with abdominal pain, such as rupture of ovarian tumor, ovarian hemorrhage, uterine adnexitis and ectopic pregnancy. Ovarian torsion has been found to represent between 2.5% and 7.4% of surgical cases of acute abdomen [7, 8]. Thus, it is not uncommon for the diagnosis to be made only after emergency diagnostic laparoscopy [9, 10]. Currently, there is no specific blood biomarker for tumor-related ovarian torsion [11, 12]. In suspected torsion, it is of primary importance to diagnose the torsion as soon as possible for emergent surgery, but it is also important to determine whether the affected ovary can be conserved by assessing for necrosis. However, determining the necrotic status of an ovary preoperatively is difficult. Mazouni et al. reported that necrosis was more frequently observed in cases in which more than 10 h had passed since the onset of abdominal pain . On the other hand, Bar-On et al. reported that patients undergoing operations less than 10 h after admission were statistically more likely to have ovarian torsion . In this study, the mean CRP level was significantly higher in the group undergoing surgery at 10 h or more than in the group undergoing surgery at less than 10 h. Histologically confirmed necrosis was only observed in the group undergoing surgery at 10 h or more. Some studies have reported that ovarian torsion could occur following ovarian stimulation [14, 15, 16]. In this study, however, all ovarian torsion cases were associated with ovarian tumor.
Therefore, ovarian necrosis caused by ovarian torsion associated with an ovarian tumor tends to develop when more than 10 h have elapsed since the onset of acute abdomen, and development of necrosis leads to an elevated CRP level. The results of this study also indicate that if ovarian torsion is suspected, surgery should be performed as soon as possible at least within 10 h after the onset of acute abdomen to conserve ovarian function. In our hospital, surgery is performed promptly for an inpatient when ovarian torsion is suspected. The cases that were delayed were primarily those cases transported from other hospitals. Therefore, if the hospital does not have the appropriate operating facilities, prompt arrangement of transportation is necessary for a patient with suspected ovarian torsion.
In all the cases in this study that were classified in the necrotic group for evaluation, necrosis was seen in least a part of the tissue specimen. Although we cannot conclude from our findings that ovarian function would be lost in every patient in the necrotic group, if torsion is suspected, we believe that immediate action is necessary to preserve ovarian function. Also, in any cases where the torsion is suspected, surgery should be performed as soon as possible.
The limit of this present study is that 10 h was taken as cut-off reference time on the basis of the result indicated in the study by Mazouni et al. However, time to surgery is a continuous variable, and the cases should have been investigated at different time points especially regarding the torsion of ovary. We will address this issue more precisely in the future study, taking the time parameter as a continuous variable.
Conflicts of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
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