Robotic assisted versus conventional laparoscopic ovarian suture reapproximation in ovarian cystectomy of ovarian endometriomas in preserving ovarian reserve

Ovarian endometriosis (endometrioma, OMA) is a disease in which endometrial-like tissues grow inside or on the sur- face of the ovaries, undergoing hemorrhagic changes with Chuan Lin and Guihua Chen contributed equally to this work. Extended author information available on the last page of the article

This study aims to introduce and evaluate a novel suturing technique for treating ovarian endometriomas (OMA) using robot-assisted laparoscopy (RAL), termed the Reapproximation of Ovarian Stroma (ROS) method. The primary focus is to assess the efficacy of ROS-RAL in treating OMA and preserving ovarian reserve, as measured by anti-Müllerian hormone (AMH) levels, compared to conventional laparoscopy (CL). In this retrospective study, we evaluated 154 patients who underwent OMA resection via either CL or RAL at Jeonbuk National University Hospital in Korea between February 1, 2017, to December 31, 2023. Among the participants, 85 patients received CL using conventional ovarian surgery, while 69 patients received ROS-RAL surgery. AMH levels were measured preoperatively and at postoperative intervals of 1, 6, 12, 24, and 36 months to determine the rate of AMH decline. The incidence of diminished ovarian reserve (DOR) was assessed to evaluate the impact on ovarian function over time. Univariate and multivariate logistic regression analyses were conducted to identify factors associated with decreased ovarian reserve following OMA surgery. The ROS-RAL group exhibited higher AMH levels at postoperative months 1, 12, and 36 compared to the CL group ( p < 0.05). Further- more, the rate of AMH decline at all postoperative time points was significantly lower in the ROS-RAL group ( p < 0.05). At 36 months postoperatively, the incidence of DOR was also notably lower in the ROS-RAL group than in the CL group (27.54% vs. 44.71%, p = 0.028). Multivariate logistic regression analysis showed that ROS-RAL (OR: 0.207, 95% CI: 0.068–0.561, p = 0.003), higher preoperative AMH levels (OR: 0.43, 95% CI: 0.29–0.59, p < 0.001), unilateral cysts (OR: 3.36, 95% CI: 1.24–9.74, p = 0.020), and younger age (OR: −0.12, 95% CI: −0.16 to −0.08, p < 0.001) were found as protective factors for postoperative ovarian reserve function. Additionally, the postoperative recurrence rate in the CL group was 5.88%, while no recurrence cases were observed in the RAL group. This study demonstrates that the novel ROS-RAL surgery offers significant advantages in treating OMA and preserving ovarian function postoperatively in patients with OMA. Future research should incorporate larger sample sizes and evaluate the influence of surgical expertise and refinement in technique to substantiate and expand upon these results, ultimately contributing to optimized treatment strategies for OMA.

Ovarian endometriomas · Conventional laparoscopy · Robot-assisted laparoscopy · Reapproximation of ovarian stroma Received: 13 November 2025 / Accepted: 17 December 2025 © The Author(s) 2025 Robotic assisted versus conventional laparoscopic ovarian suture reapproximation in ovarian cystectomy of ovarian endometriomas in preserving ovarian reserve Chuan Lin1,2,3,4,5 · Guihua Chen5 · Mingda Wang5,6 · Chongkai Zhai7 · Seong-Tshool Hong5,10 · Hee-Suk Chae1,8,9 1 3 Journal of Robotic Surgery (2026) 20:138 surrounding pelvic tissues and damaging the ovarian cortex, thereby impairing its function. Patients with OMA experi - ence symptoms such as pelvic pain, dyspareunia, abnormal menstruation, infertility, and decreased ovarian function, severely affecting their quality of life and reproductive health [3]. Lifestyle factors and dietary patterns have also been shown to influence the development and progression of endometriosis [ 4]. OMA negatively impact fertility and can reduce ovarian reserve [ 5]. With the growing demand for fertility preservation, protection of ovarian function has become particularly critical [6, 7]. Despite its seriousness, there is currently no medication specifically for OMA, and only management drugs, such as hormonal treatments, are used for the purpose of relieving the symptoms. Surgical excision is generally recommended to treat OMA, particularly for patients with cysts larger than 4 cm in diameter, significant pain, poor response to medica- tion, or infertility issues with a desire for childbearing [ 8]. Application of laparoscopy in OMA treatment improves clinical outcomes compared to conventional laparotomy. Laparoscopic surgery offers several advantages, includ - ing less postoperative pain, shorter hospital stays, lower rates of adhesion formation, and a smaller impact on ovar - ian function [9, 10]. Additionally, laparoscopic cystectomy effectively reduces the recurrence of endometriotic cysts [11], and when combined with progestins or short-term contraceptives, can significantly lower postoperative pain rates. Consequently, laparoscopic excision is widely used in clinical [ 12]. However, conventional laparoscopy (CL) has certain limitations. For example, the restricted range and flexibility of the instruments can make the surgery more challenging [13]. The two-dimensional surgical view makes it difficult to identify and completely excise hidden patho - logical lesions. Furthermore, prolonged surgeries can lead to surgeon fatigue, potentially affecting surgical precision. In particularly, CL has not shown satisfactory results for OMA, especially in advanced-stage endometriosis of stage 3 or higher [ 14]. Although advanced magnetic resonance imaging techniques have improved preoperative assessment of deep infiltrating lesions and complex pelvic anatomy, they do not fundamentally address the ovarian damage caused by the surgical procedure itself [ 15]. The advent of da Vinci robot-assisted laparoscopy (RAL) has demon - strated the potential to overcome the limitations of CL. In patients with stage III-IV OMA, classified according to the ASRM endometriosis scoring system, which often involves extensive and dense pelvic adhesions1 [ 16], RAL—featur - ing 360° rotating mechanical arms and multiple degrees of freedom—improves surgical ergonomics and enables more precise adhesion dissection in most surgical cases [ 17]. Compared to CL, RAL allows surgeons to perform com - plex and delicate procedures in confined spaces, facilitating the full dissection of “frozen pelvis” conditions in stage IV endometriosis patients without requiring colon resec - tion [18]. Despite the advancements in surgical flexibility offered by RAL, the current surgical outcomes of OMA sur- gery performed with RAL does not demonstrate a clear ben- efit in preserving postoperative ovarian re serve [ 19]. This is because the surgical procedures employed in both meth - ods are fundamentally the same. In typical CL and RAL OMA surgeries, bleeding sites encountered after a strip - ping cystectomy are cauterized before suturing. However, cauterization inevitably causes significant thermal dam - age to the ovary, as the process involves burning tissue to achieve hemostasis. Suture techniques have been proposed due to concerns about ischemic irreversible thermal damage caused by cauterization. In the case of a method of achiev - ing hemostasis through pure suturing without cauterization, the ovary is penetrated, and the entire ovary is ligated mul - tiple times during suturing. While this approach avoids the thermal damage caused by cauterization, the tight physical force exerted on the entire ovary results in ischemic damage by reducing blood flow to the ovarian cortex and stroma. Consequently, the surgical outcomes of the suturing method are not significantly better than those of the cauterization

[20]. Since current surgical techniques for OMA are basically similar regardless of whether CL or RAL is used, the out - comes of RAL OMA surgery are not markedly different from those of CL [ 19]. Considering the surgical flexibility of RAL compared to CL, RAL has the potential to facilitate the development of new surgical methods that could over - come the limitations of current OMA surgeries. By leverag- ing its advanced capabilities, RAL may pave the way for improved approaches to enhance surgical outcomes and bet- ter preserve ovarian function in patients with OMA. Preservation of ovarian function is one of the primary clinical concerns in patients with OMA. With the widespread use of assisted reproductive technologies, accumulating evi- dence suggests that assisted reproductive technologies may be associated with an increased risk of certain birth defects, such as congenital heart disease, and may impose a substan- tial psychological burden on patients [ 21–24]. Therefore, promoting natural conception while reducing reliance on assisted reproductive technologies has become an impor - tant goal in the clinical management of OMA. Accordingly, numerous studies have explored the beneficial effects of optimizing ovarian physiology and improving metabolic homeostasis on reproductive outcomes [ 25–27]. Given the critical importance of ovarian reserve for fertility and pregnancy, there is an urgent need to develop a new surgi - cal method that effectively removes OMA while preserving ovarian reserve. In this work, we developed a novel RAL surgical method called Reapproximation of Ovarian Stroma 1 3 138 Page 2 of 10 Journal of Robotic Surgery (2026) 20:138 (ROS), leveraging the surgical flexibility offered by RAL. This ROS-RAL OMA surgical method is to suture only the vascular-rich ovarian stroma while avoiding the cortex after cystectomy, with the aim of avoiding thermal damage caused by cauterization and reducing physical damage to the ovarian cortex caused by tightly sewn sutures. At this time, the ovarian incision site is either tied with a suture just around the edges of the incision to maintain the shape of the ovary, or left unsutured. This approach proved effective in treating advanced-stage endometriosis and demonstrated a significant advantage in preserving ovarian function post - operatively, even in patients with OMA of advanced-stage endometriosis.

Study population Patient data were extracted from electronic medical records within the timeframe of February 1, 2017, to December 31, 2023, using the keyword “ovarian endometriosis.” A total of 259 patient records were retrieved. Inclusion crite - ria: (1). Age > 18 years; (2). Underwent surgical treatment, specifically laparoscopy or the Da Vinci robotic system; (3). Postoperative histopathological confirmation of ovar - ian endometriosis; (4). Presence of an OMA larger than 4 cm in diameter. Exclusion criteria: Exclusion criteria: (1) Incomplete general patient information; (2) History of ovarian surgery or hormone treatment within six months prior to surgery; (3) Other surgeries performed during the operation besides excision of ovarian endometriotic cysts, such as myomectomy, salpingectomy, etc.; (4) Incomplete postoperative follow-up data; (5) Presence of severe sys - temic diseases, such as malignant tumors, serious disorders of the heart, liver, kidney, hematologic, endocrine systems, or autoimmune diseases. Ultimately, 154 patients were included in the study, with 85 in the laparoscopy group and 69 in the Da Vinci robotic group (Supplemental Fig. 1). All procedures were conducted in accordance with the Declara- tion of Helsinki and approved by the Ethics Committee of Jeonbuk National University, Korea (Approval No. 2024- 08-037-004). Written informed consent was obtained from all participants prior to inclusion. Surgical procedure All CL and ROS-RAL OMA surgeries were performed under general anesthesia by the same gynecologic surgeon, H.S. Chae, with assistance from C. Lin. The CL OMA surgery procedure Using a Veress needle, a pneumoperitoneum was estab - lished through a 10 mm vertical incision below the umbi - licus, followed by the insertion of a 10 mm laparoscope. Two additional 5 mm trocars were placed to insert auxiliary instruments. After performing ovarian adhesion dissection, the endometriotic cyst was opened, and its contents were aspirated. Once the cleavage plane between the normal ovarian tissue and the cyst wall was identified, the cyst wall was separated from the ovarian parenchyma using atrau - matic forceps and counter-traction. If the cleavage plane was unclear, scissors were used to trim the cyst wall. After cyst excision, the subsequent surgical steps can be divided into two types based on whether bipolar electrocoagula - tion is applied to the bleeding site. One approach involves achieving hemostasis with electrocoagulation before sutur - ing, while the other completely avoids electrocoagulation and achieves hemostasis solely through ovarian suturing. The sutures were applied from the ovarian surface to the vicinity of the mesovarium to ensure effective hemostasis (Fig. 1). The ROS- RAL OMA surgery procedure After making a 12 mm transverse subumbilical incision, a camera port was inserted through the incision to create pneumoperitoneum. Then two 8 mm da Vinci ports were placed in the left and right lower quadrants of abdomen, respectively. A 12 mm trocar as an assistant port was placed between camera port and left da Vinci port. An incision is made on the cyst and the contents of OMA were suctioned. Adhesions between OMA and surrounding structures were lysed to expose the ovary. The cleavage plane between the normal ovarian tissue and the capsule of OMA was identi - fied. Then, OMA were removed by stripping the capsule of the cyst from the normal ovarian tissue using traction and countertraction forces. Then, only the stroma was closed, without penetrating the cortex, thereby minimizing mechan- ical injury to functional ovarian tissue. The reconstruction was completed using interrupted figure-of-eight sutures. In most cases, the edge of the ovarian incision was left unsu - tured. However, sometimes, only the edges of the ovarian incision were sutured to close the ovary in order to maintain its shape (Fig. 2). All sutures used were 3 − 0 polyglactin 910 (Vicryl®, Ethicon Ltd., Edinburgh, UK). Data collection Preoperative data recorded included patient age, body mass index (BMI), cyst size, cyst number, laterality, serum can - cer antigen (CA) 125 levels. Endometriosis was classified 1 3 Page 3 of 10 138 Journal of Robotic Surgery (2026) 20:138 Fig. 2 Schematic diagram of ROS-RAL suturing the OMA: The cyst removal process is performed similarly to CL techniques. During sutur- ing, absorbable sutures are inserted into the ovarian stroma, passed through the bleeding deep tissues, and exited through the stroma on the opposite side. This process is repeated, and the sutures are tight - ened to form an “X” shape. A knot is tied at the crossing point. The sutures do not pass through the ovarian surface cortex, and hemostasis is achieved by intermittently suturing only the ovarian stroma. Postop- eratively, the edge of the ovarian incision was left unsutured. In most cases, the ovarian incision was left unsutured; however, to preserve the ovarian shape, sutures may occasionally be applied starting from the edges of the incision, with hemostasis performed as described above Fig. 1 Schematic diagram of the procedure for CL OMA surgery: expose the cyst and make a longitudinal incision along the free side of the ovary, cutting through the ovarian cortex to the cyst wall. Aspi- rate the cyst fluid, and use dissecting forceps to bluntly separate the boundary between the cyst wall and the ovarian cortex. Completely peel off the cyst wall and hemostasis can be divided into two types: One approach involves achieving hemostasis with electrocoagulation before suturing, while the other completely avoids electrocoagulation and achieves hemostasis solely through ovarian suturing. The sutur - ing involved the full thickness of the ovarian cortex and the medulla, including both the inner and outer cortical layers, and was performed using interrupted figure-of-eight stitches 1 3 138 Page 4 of 10 Journal of Robotic Surgery (2026) 20:138 SPSS version 22.0. All hypothesis tests were two-sided, with a significance level set at p < 0.05.

Baseline characteristics of participants A total of 154 patients were included in this study, with 85 undergoing CL surgery and 69 undergoing RAL surgery (Table 1). There were no significant differences between the two groups in terms of age (CL: 30.13 ± 6.15 vs. RAL: 29.38 ± 6.26, p = 0.457) and BMI (CL: 21.45 ± 2.80 vs. RAL: 21.50 ± 2.73, p = 0.689). However, the RAL group had significantly larger cyst sizes (7.25 ± 3.47 vs. 6.19 ± 2.28, p = 0.024) and a higher number of cysts (3.90 ± 2.60 vs. 2.40 ± 1.42, p < 0.001) compared to the CL group. Addition- ally, the proportion of bilateral cases was higher in the RAL group (50.72% vs. 31.76%, p = 0.017), and most patients in this group were at stage IV of endometriosis (84.06% vs. 62.35%, p = 0.003). The rASRM score was also significantly higher in the RAL group (75.29 ± 35.37 vs. 57.09 ± 35.54, p = 0.002). There were no significant differences between the two groups in CA 125 levels, duration of surgery, and hemoglobin decline. The surgical results The intraoperative images demonstrate notable differences in the ovarian presentation between the CL and RAL groups. Supplemental Fig. 2A depicts the typical intraoperative findings of CL OMA surgery. Following cyst excisioncon - ventional suturing techniques are employed to perform full- thickness suturing of both the ovarian cortex and stroma. according to the revised American Society for Reproductive Medicine (rASRM) classification [16]. The size of the cyst was determined as the average of the sum of the long and transverse axes of the cyst, and in the case of bilateral cysts, it was determined as the sum of the sizes of the cysts on both sides. The number of cysts is referenced from the operative records, but in the case of laparoscopy, there are cases where it is not recorded, and in these cases, the number of cysts was determined based on magnetic resonance imaging. The total operation time was defined as the time from skin incision to closure. Serum hemoglobin (Hb) levels were measured pre- operatively and on the 1st days postoperatively. Anti-Mülle- rian hormone (AMH) levels were measured preoperatively and at 1, 6, 12, 24, and 36 months postoperatively. The serum AMH level was determined using a commercial kit (AMH Gen II assay; Beckman Coulter Inc., USA) and the

was recorded in ng/ml. The changes and decline rates in AMH levels (ΔAMH%) at each postoperative time point were documented, as well as the incidence of diminished ovarian reserve (DOR). ΔAMH% was calculated using the formula: 100 x (preoperative AMH - postoperative AMH) / preoperative AMH. According to the Bologna criteria, DOR was defined as AMH < 1.1 ng/ml [28]. Statistical analysis Continuous variables following a normal distribution were expressed as mean ± standard deviation (χ ± s) and compared using an independent samples t-test. Categorical variables were expressed as percentages or frequencies and compared using Pearson’s chi-squared test. Univariate and multivari- ate analyses were conducted using binary logistic regression models, with odds ratios (OR) and 95% confidence intervals (CI) calculated. Statistical analyses were performed using Table 1 Baseline characteristics of CL group versus the RAL group Total CL RAL p N = 154 N = 85 N = 69 Age, years 29.79 ± 6.19 30.13 ± 6.15 29.38 ± 6.26 0.457 BMI, kg/m2 21.56 ± 3.09 21.45 ± 2.80 21.50 ± 2.73 0.689 Cyst size, cm 6.67 ± 2.92 6.19 ± 2.28 7.25 ± 3.47 0.024 Cyst number 3.07 ± 2.16 2.40 ± 1.42 3.90 ± 2.60 < 0.001 Laterality, n (%) 0.017 Unilateral 92 (59.74) 58 (68.24) 34 (49.28) Bilateral 62 (40.26) 27 (31.76) 35 (50.72) CA 125, U/ml 65.22 ± 136.8 52.07 ± 62.84 81.43 ± 191.71 0.186 Endometriosis stage, N (%) 0.003 III 43 (27.92) 32 (37.65) 11 (15.94) IV 111 (72.08) 53 (62.35) 58 (84.06) r ASRM score 65.25 ± 36.50 57.09 ± 35.54 75.29 ± 35.37 0.002 Duration of operation, min 91.71 ± 36.21 89.19 ± 32.67 94.81 ± 40.17 0.339 Hb loss, g/dl 1.63 ± 0.80 1.57 ± 0.84 1.70 ± 0.76 0.315 BMI: body mass index, CA125: cancer antigen 125, CL: conventional laparoscopy, Hb: Hemoglobin, RAL: robot-assisted laparoscopy, r-ASRM score: revised American Society for Reproductive Medicine score 1 3 Page 5 of 10 138 Journal of Robotic Surgery (2026) 20:138 postoperatively, the AMH levels in the RAL were higher than those in the CL group (2.78 ± 1.91 vs. 2.20 ± 1.70 ng/ ml, p = 0.047). This significant difference persisted at 12 months (2.62 ± 1.82 vs. 2.06 ± 1.59 ng/ml, p = 0.043) and 36 months (2.27 ± 1.64 vs. 1.66 ± 1.50 ng/ml, p = 0.018) post- operatively (Table 2, Supplemental Fig. 3A). Regarding the decline rates in AMH levels, the RAL group had lower rates at all measured time points: 1 month (17.40 ± 36.00% vs. 40.76 ± 26.95%, p < 0.001), 6 months (19.74 ± 40.09% vs. 43.08 ± 34.85%, p < 0.001), 12 months (21.68 ± 38.79% vs. 43.35 ± 28.58%, p < 0.001), 24 months (24.08 ± 37.89% vs. 44.00 ± 28.88%, p < 0.001), and 36 months (30.43 ± 37.30% vs. 48.27 ± 35.76%, p < 0.001) (Table 2, Supplemental Fig. 3B). Incidence of diminished ovarian reserve (DOR) post- surgery There was no significant difference in the preoperative inci- dence of DOR between the CL group and the RAL group (CL: 12.94%, RAL: 14.49%, p = 0.780). At 1 month postop- eratively, the incidence of DOR was similar between the two groups (CL: 18.82%, RAL: 18.84%, p = 0.998). Over time, the incidence of DOR gradually increased in the CL group. By 36 months postoperatively, the incidence of DOR in the CL group was significantly higher than in the RAL group, with this difference being statistically significant (27.54% vs. 44.71%, p = 0.028) (Table 3, Supplemental Fig. 3C). Univariate and multivariate logistic regression analysis of DOR incidence at 3-year follow-up In the univariate and multivariate logistic regression analy - sis of DOR incidence at 3 years post-surgery between the CL group and the RAL group, several variables were found to be significantly associated with DOR. Univariate analysis revealed that age (OR: 1.20, p < 0.001), laterality (bilateral, OR: 2.26, p = 0.017), surgical duration (OR: 1.01, p = 0.041), RAL surgery (OR: 0.47, p = 0.029), and preoperative AMH levels (OR: 0.41, p < 0.001) were associated with DOR. In contrast, variables such as the number and size of ovarian cysts, BMI, CA 125 levels, and endometriosis stage (III and IV) did not show significant associations in the univariate analysis. In the multivariate analysis, younger age (OR: 0.12, 95% CI: 0.08–0.16, p < 0.001), bilateral cysts (OR: Bluish discoloration observed in portions of the surgical- side ovary suggests potential ischemic injury. In contrast, Supplemental Fig. 2B illustrates the intraoperative findings during RAL surgery. The innovative ROS suturing technique eliminates the need for suturing the ovarian cortex, selec - tively targets the vascular-rich ovarian stroma, effectively reducing the mechanical stress exerted on ovarian tissue by sutures. This approach not only improves ovarian perfusion, but also allows tissue suturing to be performed more eas - ily and with greater precision and control compared with conventional laparoscopic suturing, owing to the enhanced dexterity provided by the robotic system, thereby improv - ing operative efficiency. Notably, Supplemental Fig. 2-B3 reveals that the surgical-side ovary in the ROS-RAL group exhibits coloration consistent with the non-operated contra- lateral ovary, indicating that ovarian perfusion has been well preserved. At this time, the edges of the ovarian incision were sutured to close the ovary. Supplemental Fig. 2-B3 shows that the surgical-side ovary in the ROS-RAL group demonstrates no discoloration compared with the non-oper- ated contralateral ovary, indicating that ovarian perfusion has been well preserved. AMH levels and decline rates Preoperative AMH levels showed no significant differ - ence between the two groups (CL: 3.68 ± 2.69 ng/ml, RAL: 3.78 ± 2.43 ng/ml, p = 0.817). However, at 1 month Table 2 AMH levels and AMH decline rate between CL group and RAL group CL RAL p AMH, ng/ml Pre-operation 3.68 ± 2.69 3.78 ± 2.43 0.817 1 month 2.20 ± 1.70 2.78 ± 1.91 0.047 6 months 2.07 ± 1.43 2.53 ± 1.58 0.062 12months 2.06 ± 1.59 2.62 ± 1.82 0.043 24 months 2.00 ± 1.51 2.48 ± 1.69 0.065 36 months 1.66 ± 1.50 2.27 ± 1.64 0.018 ΔAMH, % 1 month 40.76 ± 26.95 17.40 ± 36.00 < 0.001 6 months 43.08 ± 34.85 19.74 ± 40.09 < 0.001 12 months 43.35 ± 28.58 21.68 ± 38.79 < 0.001 24 months 44.00 ± 28.88 24.08 ± 37.89 < 0.001 36 months 48.27 ± 35.76 30.43 ± 37.30 < 0.001 AMH: anti-Müllerian hormone, CL: conventional laparoscopy, RAL: robot-assisted laparoscopy Table 3 DOR between CL group and RAL group The incidence of DOR Pre-operation 1 month 6 months 12 months 24 months 36 months CL, n (%) (n = 85) 11 (12.94) 16(18.82) 20 (23.53) 23 (27.06) 29 (34.12) 38(44.71) RAL, n (%) (n = 69) 10 (14.49) 13 (18.84) 14 (20.29) 16 (23.19) 18 (26.09) 19 (27.54) P 0.780 0.998 0.630 0.583 0.282 0.028 AMH: anti-Müllerian hormone, CL: conventional laparoscopy, DOR: diminished ovarian reserve, RAL: robot-assisted laparoscopy 1 3 138 Page 6 of 10 Journal of Robotic Surgery (2026) 20:138 [29, 30]. In both surgical methods, hemostasis of the vascu- lar-rich ovarian stroma, from which the OMA is removed, is typically achieved through cauterization prior to suturing or by tightly ligating the incised ovary using the suturing method. While these approaches are effective for achieving hemostasis, they result in ischemic damage to the operated ovary. The cauterization method achieves hemostasis by burning the bleeding vessels, and the burned site inevitably causes ischemic damage, leading to a reduction in ovarian reserve. Studies on OMA surgery repeatedly reported that cauterization method significantly reduces ovarian reserve and function, and can even cause ovarian dysfunction or failure [31, 32]. Due to the limitations of ovarian reserve preservation with cauterization method, suturing method, which achieve hemostasis by tightly ligating the bleed - ing ovary, have been explored. Comparative studies have shown that suture-based hemostatic methods, compared to cauterization method, slightly reduce the impact on ovarian reserve, but the improvement is not significant [33–36]. The

of suturing methods lies in ischemic damage to the distal area of the blood vessel due to restricted blood flow, highlighting the need for the development of new sur- gical methods. The unsatisfactory outcomes of current OMA surgeries

from ischemic damage caused by both cauterization and suturing methods, regardless of whether they are per - formed using CL or RAL. However, the surgical flexibility of RAL offers significant potential for the development of innovative surgical techniques. Leveraging this flexibility, 3.36, 95% CI: 1.24–9.74, p = 0.020), RAL surgery (OR: 0.207, 95% CI: 0.068–0.561, p = 0.003), and higher preoper- ative AMH levels (OR: 0.43, 95% CI: 0.29–0.59, p < 0.001) remained significantly associated with DOR (Table 4). Postoperative recurrence During a 36-month postoperative follow-up, five patients in the CL group experienced a recurrence of OMA, resulting in a recurrence rate of 5.88%, whereas no cases of recurrence were observed in the RAL group (Supplemental Fig. 3D). The average age of the five patients who experienced recurrence was 29.8 years, and their cysts had an average diameter of 5.5 cm. All five patients received postoperative pharmacological therapy to prevent recurrence; specifically, two patients were prescribed oral dienogest (Visanne ®), while the remaining three were administered combined oral contraceptives.

Preserving ovarian reserve during OMA surgery remains a significant challenge, whether performed using RAL or CL. Despite the greater precision and flexibility offered by RAL, the preservation of ovarian reserve following RAL-OMA surgery does not differ significantly from that of CL. Grow- ing evidence indicates that both CL and RAL OMA surger- ies have significantly negative impacts on ovarian reserve Table 4 The regression analysis of DOR at 36 months after surgery Variable Univariate analysis Multivariate analysis OR (95% CI) p OR (95% CI) p Age 1.20 (1.12, 1.28) < 0.001 -0.12 (-0.16, -0.08), < 0.001 BMI 1.02 (0.92, 1.14) 0.655 NA Cyst size 0.95 (0.85, 1.07) 0.429 NA Cyst number 1.01 (0.86, 1.17) 0.943 NA Laterality Unilateral Ref Ref Bilateral 2.26 (1.15, 4.41) 0.017 3.36 (1.24, 9.74) 0.020 CA 125 0.99 (0.99, 1.00) 0.055 NA Endometriosis stage Ⅲ Ref NA Ⅳ 1.76 (0.82, 3.79) 0.148 NA r ASRM score 1.01 (1.00, 1.02) 0.062 NA Duration of operation 1.01 (1.00, 1.02) 0.041 1.01 (0.997, 1.02) 0.170 Hb loss 0.99 (0.66, 1.48) 0.949 NA Surgical approach CL Ref Ref RAL 0.47 (0.24, 0.93) 0.029 0.207 (0.068, 0.561) 0.003 Pre-operation AMH 0.41 (0.31, 0.56) < 0.001 0.43 (0.29, 0.59) < 0.001 AMH: anti-Müllerian hormone, BMI: body mass index, CA125: cancer antigen 125, CL: conventional laparoscopy, DOR: diminished ovarian reserve, Hb: Hemoglobin, NA: not available, RAL: robot-assisted laparoscopy, r-ASRM score: revised American Society for Reproductive Medicine score, Ref: reference 1 3 Page 7 of 10 138 Journal of Robotic Surgery (2026) 20:138 of recurrence were observed in the RAL group (Supplemen- tal Fig. 3D). In summary, this study demonstrated the clinical advan - tages of RAL using the ROS surgical technique for the excision of OMA, offering superior postoperative ovarian function preservation compared to traditional RAL or CL. With a follow-up period of up to three years, this study provides long-term data illustrating the impact of ROS- RAL OMA surgery on ovarian reserve. However, despite the statistical significance of these findings, our study had some limitations. First, the relatively small sample size may limit its generalizability. Second, as a single-center study, the results may be influenced by the specific surgical team’s expertise, potentially limiting the broader applicability of the conclusions. Additionally, surgical skills and experience may impact outcomes, and future studies should consider this factor.

ROS-RAL OMA surgery offers significantly favorable long-term outcomes in preserving ovarian function in OMA patients and positively impacts reducing postoperative cyst recurrence. Larger, multicenter studies are recommended to further validate these findings. Supplementary Information The online version contains supplementary material available at h t t p s : / / d o i . o r g / 1 0 . 1 0 0 7 / s 1 1 7 0 1 - 0 2 5 - 0 3 0 8 9 - 4.

The authors sincerely thank the clinical and research staff of Jeonbuk National University Hospital for their assis - tance and contributions to this study. Author contributions Conceptualization and Methodology: CL, GHC, MDW. Investigation and Formal analysis: MDW, CKZ. Visualization and Writing - Original Draft: CL, GHC, MDW. Supervision and Proj- ect administration: STH, HSC. Funding acquisition: HSC. Writing - Review & Editing: all authors. Funding This paper was supported by Fund of Biomedical Research Institute, Jeonbuk National University Hospital. Data availability Data can be made available upon reasonable request to the corresponding author. Declarations Competing interests The authors declare no competing interests. Ethics approval and consent to participate This study adheres to the principles of the Declaration of Helsinki and has received approval from the Ethics Committee of Jeonbuk National University in Korea (Ethics Approval Number: 2024-08-037-004). Consent for publication Not applicable. we developed a novel OMA surgical method, termed ROS- RAL, which has demonstrated a dramatic improvement in the preservation of ovarian reserve and function. In ROS- RAL OMA surgery, hemostasis in the vascular-rich ovarian stroma, where the OMA is removed, is achieved through meticulous interrupted suturing to reapproximate the incised ovary. Unlike previous cauterization or suturing methods, where hemostasis is harshly achieved through forcible tech- niques causing ischemic damage, hemostasis in ROS-RAL surgery is passively achieved by interrupted suturing of the incised ovarian stroma. The reapproximation of the incised ovarian stroma by interrupted suturing in ROS-RAL surgery provides sufficient hemostasis and allows the natural clo - sure of the incised ovarian cortex. Overzealous hemostasis using energy devices can lead to thermal spread, resulting in ischemic damage to the inner ovarian stromal connec - tive tissue that contains ovarian follicles. The ROS-RAL technique allows for targeted and precise suture ligation of bleeding sites, preventing unnecessary devasculariza - tion and destruction of normal ovarian tissue, optimizing the restoration of ovarian blood supply, and thereby better preserving ovarian reserve. Considering that targeted sutur- ing on connective tissues such as stroma, widely adopted in general surgery, has been shown to be effective for hemo - stasis, it is not surprising that the reapproximation of the incised ovarian stroma achieves sufficient hemostasis in the ROS-RAL surgical method. The most unique aspect of ROS-RAL OMA surgery is its use of targeted interrupted sutures on the incised ovar - ian stroma to achieve hemostasis through reapproximation of the incised ovarian stroma. This method reapproximates the incised ovarian stroma, allowing the ovarian cortex to close naturally and the incised ovary to heal gradually. This approach minimizes trauma to ovarian tissue and optimizes postoperative restoration of ovarian blood supply, thereby more effectively preserving ovarian reserve. Our study dem- onstrated that ROS-RAL OMA surgery was significantly more effective in preserving ovarian reserve in patients with OMA compared to current OMA surgical methods. The ROS-RAL OMA group exhibited significantly higher AMH levels at all postoperative time points (1, 12, and 36 months) (Table 2) compared to the CL group, with a notably lower rate of AMH decline. Furthermore, the incidence of DOR at the 36-month follow-up was significantly lower in the RAL group than in the CL group (27.54% vs. 44.71%, P = 0.028) (Table 3). 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