Recurrent torsion of otherwise normal adnexa: oophoropexy does not prevent recurrence

Recurrence of adnexal torsion involving otherwise normal adnexa is not rare. Various oophoropexy (ovarian fixation) procedures have been suggested to prevent recurrence; however, long-term information of their efficacy is lacking. The aim of this study was to investigate the recurrence rate of adnexal torsion following oophoropexy. Retrospective cohort study, including all consecutive patients who underwent an oophoropexy procedure for the prevention of recurrent torsion of “normal adnexa” in our department from 2008 to 2019 by shortening of the utero-ovarian ligament. Nineteen patients (age range 7–35 years) with a mean follow-up of 90.9 ± 57.7 months were identified. Fifteen of them (78.9%) were re-operated for recurrent torsion following an oophoropexy procedure, while four (21.1%) did not experience recurrence. Nine torsion recurrences following an oophoropexy occurred within the first 2 postoperative years. There were no differences in mean age and menarcheal status )pre- or post-menarcheal) at the time of the first torsion event, age at the time of oophoropexy, oophoropexy side, number of adnexal torsion events before oophoropexy, and follow-up duration between those with and those without post-oophoropexy recurrences. Oophoropexy procedure by shortening of the utero-ovarian ligament may not prevent recurrent torsion of otherwise normal adnexa. Further studies to determine whether combined fixation (utero-ovarian and round ligament plication) is more efficacious than isolated utero-ovarian plication for the prevention of recurrent torsion are warranted.


Introduction
Adnexal torsion is a gynecologic emergency occurring in pre-menarcheal girls, teens, and women of reproductive age, necessitating prompt surgical treatment, usually by laparoscopy [1]. The pathophysiology of adnexal torsion is unknown. However, cases of adnexal torsion may be classified into two distinct groups: torsion involving ovarian or paratubal cysts (torsion of "pathologic" adnexa), and torsion of otherwise "normal adnexa". In the former group, the surgical treatment includes adnexal untwisting and cystectomy, and the risk of recurrent torsion is very low [2,3]. In the latter group, the surgical management includes only untwisting of the adnexa, and the reported risk of torsion recurrence is high, reaching 40-60% [3,4]. Furthermore, torsion recurrence in women with a history of torsion of otherwise normal adnexa may involve the contralateral adnexa, possibly leading to devastating fertility sequelae [5].
Various adnexal fixation (oophoropexy) procedures have been proposed with the aim of reducing the risk for recurrent torsion of otherwise normal adnexa [6,7]. These procedures include plication and shortening of the utero-ovarian ligament (Fig. 1), and fixation of the ovary to the round ligament. A novel oophoropexy procedure combining the plication of the utero-ovarian ligament and fixation to the round ligament has recently been described (Fig. 2) [8]. Descriptions of all oophoropexy procedures have been limited to retrospective case reports and small case series with varying follow-up periods [6][7][8][9], and recent case reports have suggested that recurrent torsion following oophoropexy is not uncommon [8,9].
The aim of the current study is to investigate the rates of recurrent torsion following oophoropexy by shortening of the utero-ovarian ligament for preventing torsion of otherwise normal adnexa in a long-term retrospective study.

Study design
All consecutive women who underwent surgical oophoropexy between 1/2008 and 12/2019 in the Obstetrics and Gynecology Department of Shamir (Assaf Harofe) Medical Center, Zerifin, Israel were identified through a retrospective search of our computerized database. Their medical records were reviewed for demographic information, medical and surgical history, operative reports, and follow-up clinical and emergency department visits.
The oophoropexy procedures were offered to patients with recurrent torsion of otherwise normal adnexa, either at the time of an urgent laparoscopy for de-torsion or as an elective procedure. Only the ipsilateral adnexa (i.e., the adnexa diagnosed with recurrent torsion) was fixed in the initial oophoropexy surgery. For the sake of uniformity, only cases of utero-ovarian plication were included in the current study.

Procedure
The plication of the utero-ovarian ligament was performed by passing a running suture from the ovary to the uterus through the ligament and tying it either intra-or extracorporeally, bringing the ovary adjacent to the uterus. All fixations were performed with non-absorbable 2-0 Ethibond or 2-0 Prolene sutures (Ethicon, Johnson & Johnson, NJ, USA). All of the procedures were performed laparoscopically, with the exception of one patient who had a concomitant laparotomic myomectomy.
Patients who underwent oophoropexy procedures were scheduled for yearly clinic visits. Women whose information on a follow-up visit within the last year was not available in the medical records were contacted by telephone to enquire about torsion recurrence.

Statistics
The statistical analysis was performed with the SPSS software (version 26, IBM Corp.). Descriptive variables are presented as mean ± standard deviation or as median (range). Frequencies were compared with the Chi-square test or with the Fisher's exact test. Means and medians were compared with the Student t test or with the ANOVA test as appropriate. A P value < 0.05 was considered statistically significant.

Ethics
The study was approved by the institutional Review Board (#0332-19-ASF, approved on September 2nd, 2020) which waived informed consent for this retrospective review of medical records. Oral informed consent was obtained from all patients who were contacted by telephone for the acquisition of follow-up information.

Results
Nineteen patients underwent oophoropexy procedure by shortening of the utero-ovarian ligament during the study period (Fig. 3), and 15 of them (78.9%) were re-operated for recurrent torsion, while the remaining four (21.1%) did not sustain a recurrence. Fourteen of those 15 women (93.3%) underwent a second oophoropexy procedure, and one patient opted for a unilateral salpingo-oophorectomy. Torsion recurred following the second oophoropexy in four of those 14 (28.6%) cases: it was managed by a third oophoropexy in two cases and by a unilateral salpingooophorectomy in the other two cases (Fig. 3). The mean follow-up period for the entire study cohort (calculated from their first oophoropexy to their clinic or telephone followup) was 90.9 ± 57.7 months. The demographic and surgical characteristics of the study cohort at the time of the first oophoropexy procedure are shown in Table 1.
The demographic and surgical characteristics were compared between patients with recurrent torsion following oophoropexy (N = 15), and the patients without recurrence (N = 4) ( Table 2). No statistically significant differences were found in patients' age and menarcheal status (pre-or postmenarcheal) at the time of the first torsion event, age at the time of the oophoropexy, laterality of the oophoropexy, number of adnexal torsion events before the oophoropexy, urgent versus elective fixation procedure, and follow-up duration. Recurrent torsion was noted to have occurred within the first 2 years after oophoropexy in 9 cases.
Two patients in our cohort had presented with bilateral asynchronous torsion. The first patient was diagnosed with left adnexal torsion causing complete adnexal necrosis at the age of 13 years. She was subsequently operated for three episodes of right adnexal torsion for which three separate oophoropexy procedures were performed, after which there have not been any additional recurrences to date. The second patient was operated for right adnexal torsion at the age of 16 years. She underwent re-torsion of the right ovary 2 years later, and sustained two episodes of left ovarian torsion over the next 2 years. No further torsion events occurred following two oophoropexy procedures of both ovaries.

Discussion
Oophoropexy procedures appear to have limited efficacy in the prevention of recurrent torsion events in women diagnosed with torsion of otherwise normal adnexa, with recurrences having occurred in 70% of our cases. This finding is in accordance with previous anecdotal case reports which described recurrent torsion following fixation [8,9]. Three retrospective case series described a post-oophoropexy recurrence rate in the range of 10-17% [2,6,10]. However, the follow-up time in those reports was either unspecified, short (~ 2 years), or incomplete, and the indications for oophoropexy were broad, including torsion of "pathologic" adnexa whose recurrence risk is very low [2].  The etiology of torsion and recurrent torsion involving otherwise normal adnexa is unknown. It has been hypothesized that elongated adnexal ligaments (the utero-ovarian ligaments in particular) may predispose to this condition. However, the utero-ovarian ligaments may also become elongated secondary to the repeated twisting of the adnexa at the time of torsion, making it difficult to differentiate between the cause and the effect of elongated ligaments.
The common practice of ovarian fixation for the prevention of torsion is to shorten the adnexal ligaments and/or anchor the ovary to an adjacent pelvic structure, such as the round ligaments, the uterus, the pelvic sidewalls, or the utero-sacral ligaments. Due to the rarity of this condition, the different fixation techniques have not been compared to date and the optimal procedure has not yet been determined. Due to the high rate of failure with the utero-ovarian plication procedure in our patients, different fixation procedures such as the combined utero-ovarian and round ligament fixation may be considered. The combined technique has the advantage of additional anchoring of the adnexa. However, this procedure is more technically difficult to execute and may cause occlusion of the fallopian tube in the process. Further studies are needed to determine whether the combined plication is more efficacious in prevention of recurrent torsion.
Our practice has been to offer oophoropexy to patients who have experienced at least two torsion episodes. This practice may have contributed to the high failure rate of oophoropexy in our current study. If recurrent torsion events do cause further elongation of the adnexal ligaments, performing the oophoropexy after one episode of torsion may increase its success rate. Nevertheless, it is important to bear in mind that oophoropexy is often not technically feasible at the time of the first torsion episode because the massive adnexal enlargement and edema preclude effective suturing.
As such, the optimal timing of oophoropexy remains a matter of controversy.
In the current study, the follow-up period for the nonrecurrence group was shorter than for the recurrence group, albeit without reaching statistical significance. Thus, the recurrence rate may have been underestimated in our study, and longer follow-up may have revealed additional recurrences.
In the view of the failure of surgical techniques to prevent recurrent torsion, non-surgical strategies should be considered. These strategies include the prescription of hormonal contraceptives, with the view that small functional cysts may increase the risk for torsion. However, that approach has not been studied to date. Additionally, fertility preservation with oocyte or ovarian tissue cryopreservation may be considered in patients with high-order recurrences necessitating multiple surgeries. Such an approach should allow for unilateral salpingo-oophorectomy without fertility compromise.
Our study is limited by its relatively small cohort and its retrospective design. However, given the rarity of this condition, larger cohorts would only be feasible in a multi-center or population study.

Conclusion
Oophoropexy procedure by shortening of the utero-ovarian ligament appear to have limited effect upon the prevention of recurrent torsion of otherwise normal adnexa. The optimal surgical technique for oophoropexy has not yet been established, and non-surgical strategies, such as fertility preservation, may be considered in patients with high-order torsion recurrence.