Ovarian reserve and surgical hemostasis methods for benign ovarian tumors

Benign ovarian tumors (BOT) are a common issue among women of reproductive age [1, 2]. Research indicates that incidental findings of ovarian formations occur in 6.6% of women aged 25–40 years, with 80–85% of these tumors being benign [1–4]. Over the past decade, the global incidence of BOT has doubled [5]. The most prevalent morphological variants are epithelial and germ cell tumors [5, 6]. BOT and tumor-like lesions of the ovaries manifest in various age groups: in childhood, 65% of cases are functional cysts [4, 7]; in reproductive age, serous cystadenoma and mature teratoma are predominant [4, 6]; and in women over 50 years, both tumor-like and true ovarian formations are present [4]. BOT encompasses pathological formations that arise from disruptions in the cell proliferation and differentiation processes of ovarian tissue [8].

Mature ovarian teratomas, commonly referred to as dermoid cysts, are benign germ cell tumors of the ovary that consist of well-differentiated tissues derived from at least two germ layers [9]. In contrast to malignant immature teratomas, mature teratomas lack primitive embryonic elements and are entirely composed of various types of mature tissues [9]. Macroscopically, a mature teratoma typically appears as a cystic formation (dermoid cyst) containing sebaceous detritus, hair, and other tissues of ectodermal origin. Dense inclusions, such as fragments of bone tissue or teeth, are often found within the cyst cavity [8–10]. Histologically, the tumor displayed a disorganized mixture of mature tissues, originating from all three germ layers. Characteristic findings include areas of skin with appendages (hair, sebaceous glands), adipose and muscle tissue, cartilage, and bone, as well as epithelial structures resembling intestinal or respiratory epithelium. This polymorphism reflects the original germ cell's ability to differentiate into various cell lines [8–10]. Mature ovarian cystic teratomas comprise 15 to 20% of all ovarian tumors [11, 12].

Benign serous ovarian tumors account for 16% of all epithelial neoplasms of the ovaries and cover two-thirds of benign epithelial ovarian tumors [13]. They occur in women whose average age ranges from 40 to 60 years old. They are bilateral in 10–20% of the cases. They have a smooth outer surface and contain one or more thin-walled cysts filled with clear fluid. Serous cystadenomas are usually single-chambered, but can also be multichambered. Approximately 80% of mucinous ovarian tumors are benign [13]. Ovarian cystadenoma is a common benign epithelial neoplasm with favorable prognosis. The two most common types are serous and mucinous cystadenomas, whereas endometrioid and clear cell cystadenomas are rare. Mucinous cystadenomas have a smooth surface and are usually multi-chambered, but single-chambered cystadenomas are also found [13].

The standard treatment for patients of reproductive age is cystectomy, with maximum preservation of healthy ovarian tissue [1]. However, surgical treatment can have a detrimental effect on the ovarian reserve, which can occur due to thermal damage to the follicles during surgical hemostasis [1]. Therefore, in gynecological surgery, the development, optimization, and implementation of new methods of surgical hemostasis are constantly underway, while maintaining a balance between effective hemostasis and minimal damage to the ovarian tissue [1].

The ovarian reserve is the functional reserve of the ovary, which determines the ability of the latter to develop a healthy follicle with a full-fledged egg and an adequate response to ovarian stimulation [14]. Various tests and markers are used to assess ovarian reserve, such as serum levels of estradiol, follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH), inhibin-B, and the number of antral follicles (AFC), of which AMH is the main marker [2, 12, 15]. This hormone is a glycoprotein produced by granulosa cells of ovarian follicles [2].

The main methods of stopping bleeding after removal of ovarian cysts are electrosurgical bipolar coagulation, suturing of the ovary, and the use of fibrin glue [16]. In laparoscopy, the most commonly used method of hemostasis is bipolar coagulation [17]. In gynecological surgery, bipolar forceps with 3 mm wide electrodes are preferred. When precise and limited coagulation is required or when it is necessary to reduce the degree of thermal effect, bipolar branches of 1.5 mm should be used [17]. New rotary bipolar instruments (bipolar grasping forceps and RoBi scissors) meet the basic requirements of surgery, including dissection, grasping, and hemostasis [17].

The modern method used for this purpose is fibrin glue [1]. Glue is applied locally to bleeding surfaces or wound edges. The tissues are grasped (glued) within a few minutes [1, 18]. Fibrin glue is a two-component biological glue containing high concentrations of blood clotting factors (fibrinogen, thrombin, calcium ions, factor VIII, etc.) [1, 18]. When the components are mixed, it reproduces the final stage of the coagulation cascade: a fibrin clot is formed, gluing the tissues. The resulting fibrin clot firmly adheres to the tissues, closes defects, and stops bleeding (hemostatic effect), and also serves as a framework for cells and growth factors that promote wound healing. Fibrin glue is biocompatible and gradually dissolves enzymatically, leaving no foreign material in the tissue [1, 18]. In surgery, fibrin glue is used to improve hemostasis, seal tissues, and accelerate wound healing [1, 18]. Fibrin glue is indicated as a hemostatic agent when it is necessary to stop bleeding and close a defect in ovarian tissue while preserving ovarian function as much as possible [16].

The advantage of using fibrin glue lies in its application, which does not result in tissue trauma or ischemia while simultaneously achieving adhesive, hemostatic, and sealing effects that positively influence wound healing [19, 20]. In contrast, standard hemostasis methods can lead to irreversible neurogenic and microcirculatory disorders in the ovarian tissue, damage to the follicular apparatus, and ultimately ovarian failure [21, 22]. In gynecology, the use of glue in organ-preserving surgery is a potential means of enhancing fertility preservation. By maintaining the ovarian reserve and reducing the formation of adhesions, the likelihood of a successful pregnancy in the future is increased [21].

This study aimed to evaluate the state of ovarian reserve in reproductive-aged patients with BOT, employing various methods of surgical hemostasis and subsequently analyzing their effects on the preservation of the follicular apparatus.

Materials and methods

An analysis of treatment results was conducted for 156 reproductive-age patients (18–45 years old) hospitalized in the gynecological department of the V.I. Kulakov NMRC for OG&P, Ministry of Health of Russia, all diagnosed with "ovarian cystic formation (cystadenoma and/or teratoma)" during the period from 2022 to 2024. Patients provided informed consent to participate in the study, which was reviewed and approved by the Research Ethics Committee of V.I. Kulakov NMRC for OG&P (Ref. 10.11.2022).

All patients underwent a standard examination according to an accepted algorithm, which included clinical and laboratory assessments; oncological marker level studies (CA-125, CA 19-9, HE 4, CEA); measurements of serum AMH, estradiol, inhibin B, luteinizing hormone (LH), FSH; and pelvic ultrasound (US) to measure ovarian volume, antral follicle count (AFC), and intra-ovarian blood flow with determination of the resistance index (RI).

The patients were divided into two groups based on the selected surgical hemostasis method: group 1 used fibrin glue (n=78), and group 2 used bipolar coagulation (n=78).

All the patients underwent organ-sparing laparoscopic surgery using a standard technique. After creating the pneumoperitoneum, a Karl Storz laparoscope and trocar for the second puncture were sequentially introduced into the abdominal cavity. Typically, 3–4 trocars were used (an optical trocar in the periumbilical area and additional trocars in the left/right iliac and suprapubic areas), depending on the cyst size and anatomy. The main stages of the procedure included tumor enucleation, hemostasis, ovarian edge approximation, and extraction of the operational material.

On the ovarian surface above the cyst, the thinnest and least vascularized area of the tunica albuginea was grasped with an atraumatic clamp and a longitudinal incision was made to initiate cyst enucleation. After incision, the plane between the cyst wall and the surrounding ovarian tissue was carefully identified. The ovarian cyst was shelled out using atraumatic clamps. The macro preparations were removed in an endoscopic container through a trocar opening. Hemostasis was achieved using one of the selected methods: bipolar coagulation (n=78) or fibrin glue (n=78).

During the procedure, the operative field was periodically irrigated to cool the tissue and identify bleeding vessels. Bipolar coagulation was applied point-wise at the bleeding sites, with fragments of ovarian stroma captured or pressed with bipolar forceps tips until bleeding stopped.

The technique for introducing fibrin glue was as follows: after cyst enucleation, the ovary was removed and fixed in a "bowl" shape, oriented with the bed facing upwards. A thin layer of fibrin glue was evenly applied to cover the entire bleeding surface using a catheter applicator. Glue polymerization occurred within 1-2 minutes, achieving complete hemostasis with no additional hemostatic measures required.

Intraoperatively, macropreparations were sent for histological examination at the 1st Pathological Department of the V.I. Kulakov NMRC for OG&P, utilizing standard techniques with 4–5-micron cryosection preparation and subsequent hematoxylin and eosin staining.

The evaluation criteria for the surgical hemostasis methods included dynamics in ovarian reserve parameters before and three months after surgical treatment as well as reproductive outcomes.

Statistical analysis

Statistical analysis was performed using Microsoft Office Excel 2015 and MedCalc v.12. The normality of distribution in the samples was assessed using the Kolmogorov–Smirnov test. For normally distributed continuous data, results were described using arithmetic mean (M) and standard deviation (SD); comparisons between groups were performed using Student's parametric t-test. Categorical variables were described using counts and percentages. Pearson’s chi-square (χ²) test was used for group comparisons. Differences were considered statistically significant at p<0.05.

Results

The mean age of patients in the 1st group was 30.0 (6.7) years, and in the 2nd group – 31.0 (7.5) years. In both groups, the majority of patients were aged 30–34 years (Table 1). The main complaints were lower abdominal pain, painful menstruation, and the absence of pregnancy. The average age at menarche was 13.0 (0.8) years. The duration of the menstrual cycle was 28.0 (2.5) days, and the duration of menstruation was 5.0 (0.8) days. Heavy menstruation was observed in 61/156 (39%) women, moderate in 95/156 (61%), and scanty was not detected. Painful menstruation was noted in 31/156 (20%) patients. Regarding the medical history, 46/156 (29%) women had timely deliveries, 16/156 (10%) had missed miscarriages, and 6/156 (4%) had ectopic pregnancies.

In 83/156 (53%) women, a combined pathology of the pelvic organs was detected, including adhesions, uterine fibroids, endometrial polyps, and developmental anomalies of the reproductive organs.

A total of 32/156 (21%) women had previously undergone surgical treatment for ovarian cystic formation, and 8/156 (5%) had undergone unilateral adnexectomy (Fig. 1).

Pelvic US revealed cystic formations (teratomas and/or cystadenomas) of various sizes. The ovarian volume in the 1st group averaged 46.6 (50.4) cm³, AFC – 5.0 (5.2), RI – 0.9 (0.2). In the 2nd group, the ovarian volume was 45.4 (52.9) cm³, AFC – 4.0 (2.6), RI – 0.9 (0.1) (Table 2).

Before surgical treatment, the AMH level in the 1st group was on average 2.2 (1.5) ng/mL, LH – 6.6 (6.0) mIU/mL, FSH – 7.1 (5.5) mIU/mL, estradiol – 173.0 (89.4) pg/mL, inhibin B – 65.7 (31.0) pg/mL, CA-125 – 13.6 (5.4) U/mL, CA 19-9 – 12.1 (16.5) U/mL, N4 – 43.7 (9.2) pmol/L, REA – 0.8 (1.2) ng/mL (Table 2).

In the 2nd group, the AMH level before surgery was on average 2.0 (1.6) ng/mL, LH – 4.5 (7.3) mIU/mL, FSH – 9.6 (9.1) mIU/mL, estradiol – 183.8 (120.4) pg/mL, inhibin B – 64.9 (35.3) pg/mL, CA-125 – 11.2 (10.3) U/mL, CA 19-9 – 10.3 (21.9) U/mL, N4 – 44.5 (16.5) pmol/L, REA – 1.1 (0.8) ng/mL (Table 2).

In 92/156 (59%) women, histological examination revealed mature ovarian teratomas; in 64/156 (41%), serous/mucinous ovarian cystadenomas; and in 6/156 (4%), cystadenomas and teratomas (Fig. 2). In 130/156 (83%) patients, the formations were unilateral, and bilateral cysts were found in 26/156 (17%) cases. The sizes of the cystic formations ranged from 1.5 to 20.0 cm. The average tumor size in the 1st group was 4.0 (3.2) cm, and in the 2nd group – 5.0 (4.1) cm.

The operation time in the 1st group averaged 55 (17.1) minutes, and in the 2nd group – 55 (14.2) minutes, depending on the tumor size, extent of damage, and presence of adhesions. Blood loss in the 1st group averaged 20.0 (23.1) mL in the 2nd group – 30.0 (21.5) mL in the second group. No postoperative complications occurred.

After surgery, patients were monitored and examined at their place of residence, and of 2/156 (1%) women experienced recurrences three months post-operation. At the time of the study, 94/156 (60%) patients had planned pregnancy, including 50/78 (64%) in the 1st group and 44/78 (56%) in the 2nd group. Pregnancy occurred in 32/78 (41%) patients in the 1st group and in 29/78 (37%) in the 2nd group, with assisted reproductive technologies used in 9/32 (28%) in the 1st group and 12/29 (41%) in the 2nd group. The time to pregnancy ranged from three to seven months after surgery. There were no cases of pregnancy termination or miscarriages.

Laboratory and ultrasound data were analyzed three months after surgery.

The ovarian volume in the 1st group was on average 6.9 (1.3) cm³, AFC – 6.0 (3.0), RI – 0.6 (0.2). In the 2nd group, ovarian volume was 5.0 (1.3) cm³, AFC – 2.0 (2.3), RI – 0.9 (1.0) (Table 3).

After surgery, the AMH level in the 1st group was on average 1.7 (1.9) ng/mL, LH – 4.2 (2.0) mIU/mL, FSH – 6.5 (3.3) mIU/mL, estradiol – 98.4 (76.5) pg/mL, inhibin B – 59.9 (28.3) pg/mL, CA-125 – 8.5 (9.3) U/mL, CA 19-9 – 8.4 (3.8) U/mL, N4 – 33.0 (8.5) pmol/L, REA – 1.2 (0.5) ng/mL (Table 3).

In the 2nd group, the AMH level was 1.2 (1.0) ng/mL, LH – 3.4 (2.5) mIU/mL, FSH – 9.0 (5.8) mIU/mL, estradiol – 104.5 (86.9) pg/mL, inhibin B – 45.1 (23.8) pg/mL, CA-125 – 12.3 (8.6) U/mL, CA 19-9 – 8.5 (8.8) U/mL, N4 – 31.6 (10.6) pmol/L, REA – 1.2 (1.1) ng/mL (Table 3).

Statistically significant differences between the groups were found for the following indicators: AMH (Fig. 3), FSH, inhibin B, ovarian volume, AFC, and RI, indicating a more pronounced reduction in ovarian reserve with traditional hemostasis methods. In the group in which surgical hemostasis with fibrin glue was used, AFC, AMH, and inhibin B levels before and after surgery did not change significantly (p>0.05).

Discussion

The social and medical significance of BOTs arises not only from the increasing incidence of the condition but also from the demographic shift in the disease: 48.8% of women diagnosed with ovarian neoplasms are of an early reproductive age [5].

Patient management should be tailored to individual characteristics, including cyst size, access to the ovaries, ovarian reserve, age, previous adnexal surgeries, and symptoms [23]. The primary treatment for BOT is surgery, predominantly laparoscopy [4, 10, 24]. In the surgical management of BOT, key considerations include the timeliness and accuracy of diagnosis, preservation of reproductive potential, especially ovarian reserve, use of sparing techniques for hemostasis, adherence to ablastics principles, and prevention of recurrence [4, 10, 24]. Prior to undergoing surgical interventions on the ovaries, patients should be informed about the risk of decreased ovarian reserve and the option for cryopreservation of oocytes to facilitate delayed motherhood [17]. Organ-preserving surgical procedures on the ovaries of young women should be conducted by highly skilled surgeons, and it is advisable to employ sparing hemostatic methods that minimize thermal damage to the ovarian tissue [1].

All surgical energy modalities – mechanical, electrical, thermal, welding, laser, or ultrasonic scalpel, as well as chemical adhesives—can negatively affect ovarian tissue and diminish ovarian reserve in reproductive-age women, depending on various pathophysiological mechanisms [25]. Bipolar electrocoagulation is the conventional method for achieving surgical hemostasis during laparoscopic cystectomy. However, it can cause local thermal damage, potentially reducing ovarian reserve. Given that preserving healthy and functional ovarian tissue is paramount during cystectomy, it is crucial to evaluate which hemostatic technique is the least aggressive regarding ovarian reserve [23]. Traditional methods typically involve electrocoagulation of the bleeding areas or suturing for hemostasis after ovarian cystectomy. Electrocoagulation induces coagulation necrosis in the tissues, leading to localized inflammation during healing process [18]. Fibrin glue, which closely resembles natural blood clots, elicits minimal tissue reactions, thus promoting faster healing and reducing scar tissue formation [18]. This glue can seal wound defects without thermal or mechanical effects [16].

Currently, there is no standardized approach for managing bleeding during ovarian surgery that maximally preserves the primordial pool and minimizes the loss of a woman's reproductive potential [22]. The use of hemostatic matrices for intraoperative hemostasis during surgical treatment has been shown to have a lesser negative impact on key indicators of ovarian reserve than bipolar coagulation [26]. In contrast to diathermy, which can cause diffuse damage to the surrounding tissue, fibrin glue acts locally, affecting only the area to which it is applied [21]. Therefore, the use of fibrin glue for ovarian cysts is justified, as it provides reliable hemostasis with minimal tissue trauma, which is particularly important for reproductive-age patients [21].

Conclusion

Preserving ovarian reserves is crucial for patients of reproductive age who wish to realize their reproductive potential in the future. While laparoscopic removal of benign cysts is considered an organ-preserving procedure, the presence of a cyst and its surgical removal can unintentionally decrease the ovarian reserve. However, the selection of an optimal hemostatic method can help minimize this risk. Careful and gentle execution of the operation, with atraumatic isolation of the cyst capsule and minimal loss of healthy tissue, combined with sparing hemostatic techniques, supports the preservation of reproductive potential. The use of modern hemostatic materials, particularly two-component fibrin glue, facilitates reliable control of bleeding without causing additional damage to ovarian tissue.

The findings of this study indicate that favoring fibrin hemostasis over electrocoagulation results in a significantly smaller decrease in ovarian reserve indicators. Thus, fibrin glue has emerged as a promising hemostatic agent in ovarian surgery, offering a greater sparing effect on reproductive function.