{"paper_id":"e9327cc7-5290-47e4-adeb-1807c5fc850e","body_text":"RESEARCH\nJournal of Robotic Surgery          (2026) 20:138 \nhttps://doi.org/10.1007/s11701-025-03089-4\neach menstrual cycle [ 1]. Endometrial-like tissue invades \nthe ovaries, forming cysts knowns as OMA. OMA is the \nmost common manifestation of endometriosis, account -\ning for 17% to 44% of cases [ 2]. As the condition pro -\ngresses, the cysts enlarge, causing extensive adhesions with \nIntroduction\nOvarian endometriosis (endometrioma, OMA) is a disease \nin which endometrial-like tissues grow inside or on the sur-\nface of the ovaries, undergoing hemorrhagic changes with \nChuan Lin and Guihua Chen contributed equally to this work.\nExtended author information available on the last page of the article\nAbstract\nThis study aims to introduce and evaluate a novel suturing technique for treating ovarian endometriomas (OMA) using \nrobot-assisted laparoscopy (RAL), termed the Reapproximation of Ovarian Stroma (ROS) method. The primary focus is to \nassess the efficacy of ROS-RAL in treating OMA and preserving ovarian reserve, as measured by anti-Müllerian hormone \n(AMH) levels, compared to conventional laparoscopy (CL). In this retrospective study, we evaluated 154 patients who \nunderwent OMA resection via either CL or RAL at Jeonbuk National University Hospital in Korea between February 1, \n2017, to December 31, 2023. Among the participants, 85 patients received CL using conventional ovarian surgery, while \n69 patients received ROS-RAL surgery. AMH levels were measured preoperatively and at postoperative intervals of 1, 6, \n12, 24, and 36 months to determine the rate of AMH decline. The incidence of diminished ovarian reserve (DOR) was \nassessed to evaluate the impact on ovarian function over time. Univariate and multivariate logistic regression analyses \nwere conducted to identify factors associated with decreased ovarian reserve following OMA surgery. The ROS-RAL \ngroup exhibited higher AMH levels at postoperative months 1, 12, and 36 compared to the CL group ( p < 0.05). Further-\nmore, the rate of AMH decline at all postoperative time points was significantly lower in the ROS-RAL group ( p < 0.05). \nAt 36 months postoperatively, the incidence of DOR was also notably lower in the ROS-RAL group than in the CL \ngroup (27.54% vs. 44.71%, p = 0.028). Multivariate logistic regression analysis showed that ROS-RAL (OR: 0.207, 95% \nCI: 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 \n(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 \nas protective factors for postoperative ovarian reserve function. Additionally, the postoperative recurrence rate in the CL \ngroup was 5.88%, while no recurrence cases were observed in the RAL group. This study demonstrates that the novel \nROS-RAL surgery offers significant advantages in treating OMA and preserving ovarian function postoperatively in \npatients with OMA. Future research should incorporate larger sample sizes and evaluate the influence of surgical expertise \nand refinement in technique to substantiate and expand upon these results, ultimately contributing to optimized treatment \nstrategies for OMA.\nKeywords Ovarian endometriomas · Conventional laparoscopy · Robot-assisted laparoscopy · Reapproximation of \novarian stroma\nReceived: 13 November 2025 / Accepted: 17 December 2025\n© The Author(s) 2025\nRobotic assisted versus conventional laparoscopic ovarian suture \nreapproximation in ovarian cystectomy of ovarian endometriomas in \npreserving ovarian reserve\nChuan Lin1,2,3,4,5 · Guihua Chen5 · Mingda Wang5,6 · Chongkai Zhai7 · Seong-Tshool Hong5,10 · Hee-Suk Chae1,8,9\n1 3\n\n\nJournal of Robotic Surgery          (2026) 20:138 \nsurrounding pelvic tissues and damaging the ovarian cortex, \nthereby impairing its function. Patients with OMA experi -\nence symptoms such as pelvic pain, dyspareunia, abnormal \nmenstruation, infertility, and decreased ovarian function, \nseverely affecting their quality of life and reproductive \nhealth [3]. Lifestyle factors and dietary patterns have also \nbeen shown to influence the development and progression \nof endometriosis [ 4]. OMA negatively impact fertility and \ncan reduce ovarian reserve [ 5]. With the growing demand \nfor fertility preservation, protection of ovarian function has \nbecome particularly critical [6, 7].\nDespite its seriousness, there is currently no medication \nspecifically for OMA, and only management drugs, such as \nhormonal treatments, are used for the purpose of relieving \nthe symptoms. Surgical excision is generally recommended \nto treat OMA, particularly for patients with cysts larger than \n4 cm in diameter, significant pain, poor response to medica-\ntion, or infertility issues with a desire for childbearing [ 8]. \nApplication of laparoscopy in OMA treatment improves \nclinical outcomes compared to conventional laparotomy. \nLaparoscopic surgery offers several advantages, includ -\ning less postoperative pain, shorter hospital stays, lower \nrates of adhesion formation, and a smaller impact on ovar -\nian function [9, 10]. Additionally, laparoscopic cystectomy \neffectively reduces the recurrence of endometriotic cysts \n[11], and when combined with progestins or short-term \ncontraceptives, can significantly lower postoperative pain \nrates. Consequently, laparoscopic excision is widely used \nin clinical [ 12]. However, conventional laparoscopy (CL) \nhas certain limitations. For example, the restricted range \nand flexibility of the instruments can make the surgery more \nchallenging [13]. The two-dimensional surgical view makes \nit difficult to identify and completely excise hidden patho -\nlogical lesions. Furthermore, prolonged surgeries can lead \nto surgeon fatigue, potentially affecting surgical precision. \nIn particularly, CL has not shown satisfactory results for \nOMA, especially in advanced-stage endometriosis of stage \n3 or higher [ 14]. Although advanced magnetic resonance \nimaging techniques have improved preoperative assessment \nof deep infiltrating lesions and complex pelvic anatomy, \nthey do not fundamentally address the ovarian damage \ncaused by the surgical procedure itself [ 15]. The advent \nof da Vinci robot-assisted laparoscopy (RAL) has demon -\nstrated the potential to overcome the limitations of CL. In \npatients with stage III-IV OMA, classified according to the \nASRM endometriosis scoring system, which often involves \nextensive and dense pelvic adhesions1 [ 16], RAL—featur -\ning 360° rotating mechanical arms and multiple degrees of \nfreedom—improves surgical ergonomics and enables more \nprecise adhesion dissection in most surgical cases [ 17]. \nCompared to CL, RAL allows surgeons to perform com -\nplex and delicate procedures in confined spaces, facilitating \nthe full dissection of “frozen pelvis” conditions in stage \nIV endometriosis patients without requiring colon resec -\ntion [18]. Despite the advancements in surgical flexibility \noffered by RAL, the current surgical outcomes of OMA sur-\ngery performed with RAL does not demonstrate a clear ben-\nefit in preserving postoperative ovarian re serve [ 19]. This \nis because the surgical procedures employed in both meth -\nods are fundamentally the same. In typical CL and RAL \nOMA surgeries, bleeding sites encountered after a strip -\nping cystectomy are cauterized before suturing. However, \ncauterization inevitably causes significant thermal dam -\nage to the ovary, as the process involves burning tissue to \nachieve hemostasis. Suture techniques have been proposed \ndue to concerns about ischemic irreversible thermal damage \ncaused by cauterization. In the case of a method of achiev -\ning hemostasis through pure suturing without cauterization, \nthe ovary is penetrated, and the entire ovary is ligated mul -\ntiple times during suturing. While this approach avoids the \nthermal damage caused by cauterization, the tight physical \nforce exerted on the entire ovary results in ischemic damage \nby reducing blood flow to the ovarian cortex and stroma. \nConsequently, the surgical outcomes of the suturing method \nare not significantly better than those of the cauterization \nmethod [20].\nSince current surgical techniques for OMA are basically \nsimilar regardless of whether CL or RAL is used, the out -\ncomes of RAL OMA surgery are not markedly different \nfrom those of CL [ 19]. Considering the surgical flexibility \nof RAL compared to CL, RAL has the potential to facilitate \nthe development of new surgical methods that could over -\ncome the limitations of current OMA surgeries. By leverag-\ning its advanced capabilities, RAL may pave the way for \nimproved approaches to enhance surgical outcomes and bet-\nter preserve ovarian function in patients with OMA.\nPreservation of ovarian function is one of the primary \nclinical concerns in patients with OMA. With the widespread \nuse of assisted reproductive technologies, accumulating evi-\ndence suggests that assisted reproductive technologies may \nbe associated with an increased risk of certain birth defects, \nsuch as congenital heart disease, and may impose a substan-\ntial psychological burden on patients [ 21–24]. Therefore, \npromoting natural conception while reducing reliance on \nassisted reproductive technologies has become an impor -\ntant goal in the clinical management of OMA. Accordingly, \nnumerous studies have explored the beneficial effects of \noptimizing ovarian physiology and improving metabolic \nhomeostasis on reproductive outcomes [ 25–27]. Given \nthe critical importance of ovarian reserve for fertility and \npregnancy, there is an urgent need to develop a new surgi -\ncal method that effectively removes OMA while preserving \novarian reserve. In this work, we developed a novel RAL \nsurgical method called Reapproximation of Ovarian Stroma \n1 3\n  138  Page 2 of 10\n\nJournal of Robotic Surgery          (2026) 20:138 \n(ROS), leveraging the surgical flexibility offered by RAL. \nThis ROS-RAL OMA surgical method is to suture only \nthe vascular-rich ovarian stroma while avoiding the cortex \nafter cystectomy, with the aim of avoiding thermal damage \ncaused by cauterization and reducing physical damage to \nthe ovarian cortex caused by tightly sewn sutures. At this \ntime, the ovarian incision site is either tied with a suture just \naround the edges of the incision to maintain the shape of the \novary, or left unsutured. This approach proved effective in \ntreating advanced-stage endometriosis and demonstrated a \nsignificant advantage in preserving ovarian function post -\noperatively, even in patients with OMA of advanced-stage \nendometriosis.\nMethods\nStudy population\nPatient data were extracted from electronic medical records \nwithin the timeframe of February 1, 2017, to December \n31, 2023, using the keyword “ovarian endometriosis.” A \ntotal of 259 patient records were retrieved. Inclusion crite -\nria: (1). Age > 18 years; (2). Underwent surgical treatment, \nspecifically laparoscopy or the Da Vinci robotic system; \n(3). Postoperative histopathological confirmation of ovar -\nian endometriosis; (4). Presence of an OMA larger than \n4 cm in diameter. Exclusion criteria: Exclusion criteria: \n(1) Incomplete general patient information; (2) History of \novarian surgery or hormone treatment within six months \nprior to surgery; (3) Other surgeries performed during the \noperation besides excision of ovarian endometriotic cysts, \nsuch as myomectomy, salpingectomy, etc.; (4) Incomplete \npostoperative follow-up data; (5) Presence of severe sys -\ntemic diseases, such as malignant tumors, serious disorders \nof the heart, liver, kidney, hematologic, endocrine systems, \nor autoimmune diseases. Ultimately, 154 patients were \nincluded in the study, with 85 in the laparoscopy group and \n69 in the Da Vinci robotic group (Supplemental Fig. 1). All \nprocedures were conducted in accordance with the Declara-\ntion of Helsinki and approved by the Ethics Committee of \nJeonbuk National University, Korea (Approval No. 2024-\n08-037-004). Written informed consent was obtained from \nall participants prior to inclusion.\nSurgical procedure\nAll CL and ROS-RAL OMA surgeries were performed \nunder general anesthesia by the same gynecologic surgeon, \nH.S. Chae, with assistance from C. Lin.\nThe CL OMA surgery procedure\nUsing a Veress needle, a pneumoperitoneum was estab -\nlished through a 10 mm vertical incision below the umbi -\nlicus, followed by the insertion of a 10 mm laparoscope. \nTwo additional 5 mm trocars were placed to insert auxiliary \ninstruments. After performing ovarian adhesion dissection, \nthe endometriotic cyst was opened, and its contents were \naspirated. Once the cleavage plane between the normal \novarian tissue and the cyst wall was identified, the cyst wall \nwas separated from the ovarian parenchyma using atrau -\nmatic forceps and counter-traction. If the cleavage plane \nwas unclear, scissors were used to trim the cyst wall. After \ncyst excision, the subsequent surgical steps can be divided \ninto two types based on whether bipolar electrocoagula -\ntion is applied to the bleeding site. One approach involves \nachieving hemostasis with electrocoagulation before sutur -\ning, while the other completely avoids electrocoagulation \nand achieves hemostasis solely through ovarian suturing. \nThe sutures were applied from the ovarian surface to the \nvicinity of the mesovarium to ensure effective hemostasis \n(Fig. 1).\nThe ROS- RAL OMA surgery procedure\nAfter making a 12 mm transverse subumbilical incision, \na camera port was inserted through the incision to create \npneumoperitoneum. Then two 8 mm da Vinci ports were \nplaced in the left and right lower quadrants of abdomen, \nrespectively. A 12 mm trocar as an assistant port was placed \nbetween camera port and left da Vinci port. An incision is \nmade on the cyst and the contents of OMA were suctioned. \nAdhesions between OMA and surrounding structures were \nlysed to expose the ovary. The cleavage plane between the \nnormal ovarian tissue and the capsule of OMA was identi -\nfied. Then, OMA were removed by stripping the capsule of \nthe cyst from the normal ovarian tissue using traction and \ncountertraction forces. Then, only the stroma was closed, \nwithout penetrating the cortex, thereby minimizing mechan-\nical injury to functional ovarian tissue. The reconstruction \nwas completed using interrupted figure-of-eight sutures. In \nmost cases, the edge of the ovarian incision was left unsu -\ntured. However, sometimes, only the edges of the ovarian \nincision were sutured to close the ovary in order to maintain \nits shape (Fig. 2). All sutures used were 3 − 0 polyglactin \n910 (Vicryl®, Ethicon Ltd., Edinburgh, UK).\nData collection\nPreoperative data recorded included patient age, body mass \nindex (BMI), cyst size, cyst number, laterality, serum can -\ncer antigen (CA) 125 levels. Endometriosis was classified \n1 3\nPage 3 of 10   138 \n\nJournal of Robotic Surgery          (2026) 20:138 \nFig. 2 Schematic diagram of ROS-RAL suturing the OMA: The cyst \nremoval process is performed similarly to CL techniques. During sutur-\ning, absorbable sutures are inserted into the ovarian stroma, passed \nthrough the bleeding deep tissues, and exited through the stroma on \nthe opposite side. This process is repeated, and the sutures are tight -\nened to form an “X” shape. A knot is tied at the crossing point. The \nsutures do not pass through the ovarian surface cortex, and hemostasis \nis achieved by intermittently suturing only the ovarian stroma. Postop-\neratively, the edge of the ovarian incision was left unsutured. In most \ncases, the ovarian incision was left unsutured; however, to preserve the \novarian shape, sutures may occasionally be applied starting from the \nedges of the incision, with hemostasis performed as described above\n \nFig. 1  Schematic diagram of the procedure for CL OMA surgery: \nexpose the cyst and make a longitudinal incision along the free side \nof the ovary, cutting through the ovarian cortex to the cyst wall. Aspi-\nrate the cyst fluid, and use dissecting forceps to bluntly separate the \nboundary between the cyst wall and the ovarian cortex. Completely \npeel off the cyst wall and hemostasis can be divided into two types: \nOne approach involves achieving hemostasis with electrocoagulation \nbefore suturing, while the other completely avoids electrocoagulation \nand achieves hemostasis solely through ovarian suturing. The sutur -\ning involved the full thickness of the ovarian cortex and the medulla, \nincluding both the inner and outer cortical layers, and was performed \nusing interrupted figure-of-eight stitches\n \n1 3\n  138  Page 4 of 10\n\nJournal of Robotic Surgery          (2026) 20:138 \nSPSS version 22.0. All hypothesis tests were two-sided, \nwith a significance level set at p < 0.05.\nResults\nBaseline characteristics of participants\nA total of 154 patients were included in this study, with 85 \nundergoing CL surgery and 69 undergoing RAL surgery \n(Table 1). There were no significant differences between \nthe two groups in terms of age (CL: 30.13 ± 6.15 vs. RAL: \n29.38 ± 6.26, p = 0.457) and BMI (CL: 21.45 ± 2.80 vs. \nRAL: 21.50 ± 2.73, p = 0.689). However, the RAL group had \nsignificantly larger cyst sizes (7.25 ± 3.47 vs. 6.19 ± 2.28, \np = 0.024) and a higher number of cysts (3.90 ± 2.60 vs. \n2.40 ± 1.42, p < 0.001) compared to the CL group. Addition-\nally, the proportion of bilateral cases was higher in the RAL \ngroup (50.72% vs. 31.76%, p = 0.017), and most patients in \nthis group were at stage IV of endometriosis (84.06% vs. \n62.35%, p = 0.003). The rASRM score was also significantly \nhigher in the RAL group (75.29 ± 35.37 vs. 57.09 ± 35.54, \np = 0.002). There were no significant differences between \nthe two groups in CA 125 levels, duration of surgery, and \nhemoglobin decline.\nThe surgical results\nThe intraoperative images demonstrate notable differences \nin the ovarian presentation between the CL and RAL groups. \nSupplemental Fig. 2A depicts the typical intraoperative \nfindings of CL OMA surgery. Following cyst excisioncon -\nventional suturing techniques are employed to perform full-\nthickness suturing of both the ovarian cortex and stroma. \naccording to the revised American Society for Reproductive \nMedicine (rASRM) classification [16]. The size of the cyst \nwas determined as the average of the sum of the long and \ntransverse axes of the cyst, and in the case of bilateral cysts, \nit was determined as the sum of the sizes of the cysts on both \nsides. The number of cysts is referenced from the operative \nrecords, but in the case of laparoscopy, there are cases where \nit is not recorded, and in these cases, the number of cysts was \ndetermined based on magnetic resonance imaging. The total \noperation time was defined as the time from skin incision to \nclosure. Serum hemoglobin (Hb) levels were measured pre-\noperatively and on the 1st days postoperatively. Anti-Mülle-\nrian hormone (AMH) levels were measured preoperatively \nand at 1, 6, 12, 24, and 36 months postoperatively. The \nserum AMH level was determined using a commercial kit \n(AMH Gen II assay; Beckman Coulter Inc., USA) and the \nresult was recorded in ng/ml. The changes and decline rates \nin AMH levels (ΔAMH%) at each postoperative time point \nwere documented, as well as the incidence of diminished \novarian reserve (DOR). ΔAMH% was calculated using the \nformula: 100 x (preoperative AMH - postoperative AMH) / \npreoperative AMH. According to the Bologna criteria, DOR \nwas defined as AMH < 1.1 ng/ml [28].\nStatistical analysis\nContinuous variables following a normal distribution were \nexpressed as mean ± standard deviation (χ ± s) and compared \nusing an independent samples t-test. Categorical variables \nwere expressed as percentages or frequencies and compared \nusing Pearson’s chi-squared test. Univariate and multivari-\nate analyses were conducted using binary logistic regression \nmodels, with odds ratios (OR) and 95% confidence intervals \n(CI) calculated. Statistical analyses were performed using \nTable 1 Baseline characteristics of CL group versus the RAL group\nTotal CL RAL p\nN = 154 N = 85 N = 69\nAge, years 29.79 ± 6.19 30.13 ± 6.15 29.38 ± 6.26 0.457\nBMI, kg/m2 21.56 ± 3.09 21.45 ± 2.80 21.50 ± 2.73 0.689\nCyst size, cm 6.67 ± 2.92 6.19 ± 2.28 7.25 ± 3.47 0.024\nCyst number 3.07 ± 2.16 2.40 ± 1.42 3.90 ± 2.60 < 0.001\nLaterality, n (%) 0.017\nUnilateral 92 (59.74) 58 (68.24) 34 (49.28)\nBilateral 62 (40.26) 27 (31.76) 35 (50.72)\nCA 125, U/ml 65.22 ± 136.8 52.07 ± 62.84 81.43 ± 191.71 0.186\nEndometriosis stage, N (%) 0.003\nIII 43 (27.92) 32 (37.65) 11 (15.94)\nIV 111 (72.08) 53 (62.35) 58 (84.06)\nr ASRM score 65.25 ± 36.50 57.09 ± 35.54 75.29 ± 35.37 0.002\nDuration of operation, min 91.71 ± 36.21 89.19 ± 32.67 94.81 ± 40.17 0.339\nHb loss, g/dl 1.63 ± 0.80 1.57 ± 0.84 1.70 ± 0.76 0.315\nBMI: body mass index, CA125: cancer antigen 125, CL: conventional laparoscopy, Hb: Hemoglobin, RAL: robot-assisted laparoscopy, r-ASRM \nscore: revised American Society for Reproductive Medicine score\n1 3\nPage 5 of 10   138 \n\nJournal of Robotic Surgery          (2026) 20:138 \npostoperatively, the AMH levels in the RAL were higher \nthan those in the CL group (2.78 ± 1.91 vs. 2.20 ± 1.70 ng/\nml, p = 0.047). This significant difference persisted at 12 \nmonths (2.62 ± 1.82 vs. 2.06 ± 1.59 ng/ml, p = 0.043) and 36 \nmonths (2.27 ± 1.64 vs. 1.66 ± 1.50 ng/ml, p = 0.018) post-\noperatively (Table 2, Supplemental Fig. 3A). Regarding the \ndecline rates in AMH levels, the RAL group had lower rates \nat all measured time points: 1 month (17.40 ± 36.00% vs. \n40.76 ± 26.95%, p < 0.001), 6 months (19.74 ± 40.09% vs. \n43.08 ± 34.85%, p < 0.001), 12 months (21.68 ± 38.79% vs. \n43.35 ± 28.58%, p < 0.001), 24 months (24.08 ± 37.89% vs. \n44.00 ± 28.88%, p < 0.001), and 36 months (30.43 ± 37.30% \nvs. 48.27 ± 35.76%, p < 0.001) (Table 2, Supplemental \nFig. 3B).\nIncidence of diminished ovarian reserve (DOR) post-\nsurgery\nThere was no significant difference in the preoperative inci-\ndence of DOR between the CL group and the RAL group \n(CL: 12.94%, RAL: 14.49%, p = 0.780). At 1 month postop-\neratively, the incidence of DOR was similar between the two \ngroups (CL: 18.82%, RAL: 18.84%, p = 0.998). Over time, \nthe incidence of DOR gradually increased in the CL group. \nBy 36 months postoperatively, the incidence of DOR in the \nCL group was significantly higher than in the RAL group, \nwith this difference being statistically significant (27.54% \nvs. 44.71%, p = 0.028) (Table 3, Supplemental Fig. 3C).\nUnivariate and multivariate logistic regression \nanalysis of DOR incidence at 3-year follow-up\nIn the univariate and multivariate logistic regression analy -\nsis of DOR incidence at 3 years post-surgery between the \nCL group and the RAL group, several variables were found \nto be significantly associated with DOR. Univariate analysis \nrevealed that age (OR: 1.20, p < 0.001), laterality (bilateral, \nOR: 2.26, p = 0.017), surgical duration (OR: 1.01, p = 0.041), \nRAL surgery (OR: 0.47, p = 0.029), and preoperative AMH \nlevels (OR: 0.41, p < 0.001) were associated with DOR. In \ncontrast, variables such as the number and size of ovarian \ncysts, BMI, CA 125 levels, and endometriosis stage (III and \nIV) did not show significant associations in the univariate \nanalysis. In the multivariate analysis, younger age (OR: \n0.12, 95% CI: 0.08–0.16, p < 0.001), bilateral cysts (OR: \nBluish discoloration observed in portions of the surgical-\nside ovary suggests potential ischemic injury. In contrast, \nSupplemental Fig. 2B illustrates the intraoperative findings \nduring RAL surgery. The innovative ROS suturing technique \neliminates the need for suturing the ovarian cortex, selec -\ntively targets the vascular-rich ovarian stroma, effectively \nreducing the mechanical stress exerted on ovarian tissue by \nsutures. This approach not only improves ovarian perfusion, \nbut also allows tissue suturing to be performed more eas -\nily and with greater precision and control compared with \nconventional laparoscopic suturing, owing to the enhanced \ndexterity provided by the robotic system, thereby improv -\ning operative efficiency. Notably, Supplemental Fig. 2-B3 \nreveals that the surgical-side ovary in the ROS-RAL group \nexhibits coloration consistent with the non-operated contra-\nlateral ovary, indicating that ovarian perfusion has been well \npreserved. At this time, the edges of the ovarian incision \nwere sutured to close the ovary. Supplemental Fig. 2-B3 \nshows that the surgical-side ovary in the ROS-RAL group \ndemonstrates no discoloration compared with the non-oper-\nated contralateral ovary, indicating that ovarian perfusion \nhas been well preserved.\nAMH levels and decline rates\nPreoperative AMH levels showed no significant differ -\nence between the two groups (CL: 3.68 ± 2.69 ng/ml, \nRAL: 3.78 ± 2.43 ng/ml, p = 0.817). However, at 1 month \nTable 2 AMH levels and AMH decline rate between CL group and \nRAL group\nCL RAL p\nAMH, ng/ml\nPre-operation 3.68 ± 2.69 3.78 ± 2.43 0.817\n1 month 2.20 ± 1.70 2.78 ± 1.91 0.047\n6 months 2.07 ± 1.43 2.53 ± 1.58 0.062\n12months 2.06 ± 1.59 2.62 ± 1.82 0.043\n24 months 2.00 ± 1.51 2.48 ± 1.69 0.065\n36 months 1.66 ± 1.50 2.27 ± 1.64 0.018\nΔAMH, %\n1 month 40.76 ± 26.95 17.40 ± 36.00 < 0.001\n6 months 43.08 ± 34.85 19.74 ± 40.09 < 0.001\n12 months 43.35 ± 28.58 21.68 ± 38.79 < 0.001\n24 months 44.00 ± 28.88 24.08 ± 37.89 < 0.001\n36 months 48.27 ± 35.76 30.43 ± 37.30 < 0.001\nAMH: anti-Müllerian hormone, CL: conventional laparoscopy, RAL: \nrobot-assisted laparoscopy\nTable 3 DOR between CL group and RAL group\nThe incidence of DOR\nPre-operation 1 month 6 months 12 months 24 months 36 months\nCL, n (%) (n = 85) 11 (12.94) 16(18.82) 20 (23.53) 23 (27.06) 29 (34.12) 38(44.71)\nRAL, n (%) (n = 69) 10 (14.49) 13 (18.84) 14 (20.29) 16 (23.19) 18 (26.09) 19 (27.54)\nP 0.780 0.998 0.630 0.583 0.282 0.028\nAMH: anti-Müllerian hormone, CL: conventional laparoscopy, DOR: diminished ovarian reserve, RAL: robot-assisted laparoscopy\n1 3\n  138  Page 6 of 10\n\nJournal of Robotic Surgery          (2026) 20:138 \n[29, 30]. In both surgical methods, hemostasis of the vascu-\nlar-rich ovarian stroma, from which the OMA is removed, \nis typically achieved through cauterization prior to suturing \nor by tightly ligating the incised ovary using the suturing \nmethod. While these approaches are effective for achieving \nhemostasis, they result in ischemic damage to the operated \novary. The cauterization method achieves hemostasis by \nburning the bleeding vessels, and the burned site inevitably \ncauses ischemic damage, leading to a reduction in ovarian \nreserve. Studies on OMA surgery repeatedly reported that \ncauterization method significantly reduces ovarian reserve \nand function, and can even cause ovarian dysfunction or \nfailure [31, 32]. Due to the limitations of ovarian reserve \npreservation with cauterization method, suturing method, \nwhich achieve hemostasis by tightly ligating the bleed -\ning ovary, have been explored. Comparative studies have \nshown that suture-based hemostatic methods, compared to \ncauterization method, slightly reduce the impact on ovarian \nreserve, but the improvement is not significant [33–36]. The \nlimitation of suturing methods lies in ischemic damage to \nthe distal area of the blood vessel due to restricted blood \nflow, highlighting the need for the development of new sur-\ngical methods.\nThe unsatisfactory outcomes of current OMA surgeries \nresult from ischemic damage caused by both cauterization \nand suturing methods, regardless of whether they are per -\nformed using CL or RAL. However, the surgical flexibility \nof RAL offers significant potential for the development of \ninnovative surgical techniques. Leveraging this flexibility, \n3.36, 95% CI: 1.24–9.74, p = 0.020), RAL surgery (OR: \n0.207, 95% CI: 0.068–0.561, p = 0.003), and higher preoper-\native AMH levels (OR: 0.43, 95% CI: 0.29–0.59, p < 0.001) \nremained significantly associated with DOR (Table 4).\nPostoperative recurrence\nDuring a 36-month postoperative follow-up, five patients in \nthe CL group experienced a recurrence of OMA, resulting in \na recurrence rate of 5.88%, whereas no cases of recurrence \nwere observed in the RAL group (Supplemental Fig. 3D). \nThe average age of the five patients who experienced \nrecurrence was 29.8 years, and their cysts had an average \ndiameter of 5.5 cm. All five patients received postoperative \npharmacological therapy to prevent recurrence; specifically, \ntwo patients were prescribed oral dienogest (Visanne ®), \nwhile the remaining three were administered combined oral \ncontraceptives.\nDiscussion\nPreserving ovarian reserve during OMA surgery remains a \nsignificant challenge, whether performed using RAL or CL. \nDespite the greater precision and flexibility offered by RAL, \nthe preservation of ovarian reserve following RAL-OMA \nsurgery does not differ significantly from that of CL. Grow-\ning evidence indicates that both CL and RAL OMA surger-\nies have significantly negative impacts on ovarian reserve \nTable 4 The regression analysis of DOR at 36 months after surgery\nVariable Univariate analysis Multivariate analysis\nOR (95% CI) p OR (95% CI) p\nAge 1.20 (1.12, 1.28) < 0.001 -0.12 (-0.16, -0.08), < 0.001\nBMI 1.02 (0.92, 1.14) 0.655 NA\nCyst size 0.95 (0.85, 1.07) 0.429 NA\nCyst number 1.01 (0.86, 1.17) 0.943 NA\nLaterality\nUnilateral Ref Ref\nBilateral 2.26 (1.15, 4.41) 0.017 3.36 (1.24, 9.74) 0.020\nCA 125 0.99 (0.99, 1.00) 0.055 NA\nEndometriosis stage\nⅢ Ref NA\nⅣ 1.76 (0.82, 3.79) 0.148 NA\nr ASRM score 1.01 (1.00, 1.02) 0.062 NA\nDuration of operation 1.01 (1.00, 1.02) 0.041 1.01 (0.997, 1.02) 0.170\nHb loss 0.99 (0.66, 1.48) 0.949 NA\nSurgical approach\nCL Ref Ref\nRAL 0.47 (0.24, 0.93) 0.029 0.207 (0.068, 0.561) 0.003\nPre-operation AMH 0.41 (0.31, 0.56) < 0.001 0.43 (0.29, 0.59) < 0.001\nAMH: anti-Müllerian hormone, BMI: body mass index, CA125: cancer antigen 125, CL: conventional laparoscopy, DOR: diminished ovarian \nreserve, Hb: Hemoglobin, NA: not available, RAL: robot-assisted laparoscopy, r-ASRM score: revised American Society for Reproductive \nMedicine score, Ref: reference\n1 3\nPage 7 of 10   138 \n\nJournal of Robotic Surgery          (2026) 20:138 \nof recurrence were observed in the RAL group (Supplemen-\ntal Fig. 3D).\nIn summary, this study demonstrated the clinical advan -\ntages of RAL using the ROS surgical technique for the \nexcision of OMA, offering superior postoperative ovarian \nfunction preservation compared to traditional RAL or CL. \nWith a follow-up period of up to three years, this study \nprovides long-term data illustrating the impact of ROS-\nRAL OMA surgery on ovarian reserve. However, despite \nthe statistical significance of these findings, our study had \nsome limitations. First, the relatively small sample size may \nlimit its generalizability. Second, as a single-center study, \nthe results may be influenced by the specific surgical team’s \nexpertise, potentially limiting the broader applicability of \nthe conclusions. Additionally, surgical skills and experience \nmay impact outcomes, and future studies should consider \nthis factor.\nConclusion\nROS-RAL OMA surgery offers significantly favorable \nlong-term outcomes in preserving ovarian function in OMA \npatients and positively impacts reducing postoperative cyst \nrecurrence. Larger, multicenter studies are recommended to \nfurther validate these findings.\nSupplementary Information  The online version contains \nsupplementary 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 \n2 5 - 0 3 0 8 9 - 4.\nAcknowledgements The authors sincerely thank the clinical and \nresearch staff of Jeonbuk National University Hospital for their assis -\ntance and contributions to this study.\nAuthor contributions Conceptualization and Methodology: CL, GHC, \nMDW. Investigation and Formal analysis: MDW, CKZ. Visualization \nand Writing - Original Draft: CL, GHC, MDW. Supervision and Proj-\nect administration: STH, HSC. Funding acquisition: HSC. Writing - \nReview & Editing: all authors.\nFunding This paper was supported by Fund of Biomedical Research \nInstitute, Jeonbuk National University Hospital.\nData availability Data can be made available upon reasonable request \nto the corresponding author.\nDeclarations\nCompeting interests The authors declare no competing interests.\nEthics approval and consent to participate  This study adheres to the \nprinciples of the Declaration of Helsinki and has received approval \nfrom the Ethics Committee of Jeonbuk National University in Korea \n(Ethics Approval Number: 2024-08-037-004).\nConsent for publication Not applicable.\nwe developed a novel OMA surgical method, termed ROS-\nRAL, which has demonstrated a dramatic improvement in \nthe preservation of ovarian reserve and function. In ROS-\nRAL OMA surgery, hemostasis in the vascular-rich ovarian \nstroma, where the OMA is removed, is achieved through \nmeticulous interrupted suturing to reapproximate the incised \novary. Unlike previous cauterization or suturing methods, \nwhere hemostasis is harshly achieved through forcible tech-\nniques causing ischemic damage, hemostasis in ROS-RAL \nsurgery is passively achieved by interrupted suturing of the \nincised ovarian stroma. The reapproximation of the incised \novarian stroma by interrupted suturing in ROS-RAL surgery \nprovides sufficient hemostasis and allows the natural clo -\nsure of the incised ovarian cortex. Overzealous hemostasis \nusing energy devices can lead to thermal spread, resulting \nin ischemic damage to the inner ovarian stromal connec -\ntive tissue that contains ovarian follicles. The ROS-RAL \ntechnique allows for targeted and precise suture ligation \nof bleeding sites, preventing unnecessary devasculariza -\ntion and destruction of normal ovarian tissue, optimizing \nthe restoration of ovarian blood supply, and thereby better \npreserving ovarian reserve. Considering that targeted sutur-\ning on connective tissues such as stroma, widely adopted in \ngeneral surgery, has been shown to be effective for hemo -\nstasis, it is not surprising that the reapproximation of the \nincised ovarian stroma achieves sufficient hemostasis in the \nROS-RAL surgical method.\nThe most unique aspect of ROS-RAL OMA surgery is \nits use of targeted interrupted sutures on the incised ovar -\nian stroma to achieve hemostasis through reapproximation \nof the incised ovarian stroma. This method reapproximates \nthe incised ovarian stroma, allowing the ovarian cortex to \nclose naturally and the incised ovary to heal gradually. This \napproach minimizes trauma to ovarian tissue and optimizes \npostoperative restoration of ovarian blood supply, thereby \nmore effectively preserving ovarian reserve. Our study dem-\nonstrated that ROS-RAL OMA surgery was significantly \nmore effective in preserving ovarian reserve in patients with \nOMA compared to current OMA surgical methods. The \nROS-RAL OMA group exhibited significantly higher AMH \nlevels at all postoperative time points (1, 12, and 36 months) \n(Table 2) compared to the CL group, with a notably lower \nrate of AMH decline. Furthermore, the incidence of DOR at \nthe 36-month follow-up was significantly lower in the RAL \ngroup than in the CL group (27.54% vs. 44.71%, P = 0.028) \n(Table 3). In addition, the study explored factors influenc -\ning postoperative DOR and identified that age, bilateral \nendometriomas, the CL surgical platform, and preoperative \nAMH levels were associated with DOR incidence (Table 4). \nNotably, during the 36-month postoperative follow-up, five \npatients in the CL group experienced a recurrence of OMA, \nresulting in a recurrence rate of 5.88%. 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Fertil Steril, (1985) 43(3): p. 351–352\n1 3\nPage 9 of 10   138 \n\nJournal of Robotic Surgery          (2026) 20:138 \nAuthors and Affiliations\nChuan Lin1,2,3,4,5 · Guihua Chen5 · Mingda Wang5,6 · Chongkai Zhai7 · Seong-Tshool Hong5,10 · Hee-Suk Chae1,8,9\n \r Seong-Tshool Hong\nseonghong@jbnu.ac.kr\n \r Hee-Suk Chae\nhschae@jbnu.ac.kr\n1 Department of Obstetrics and Gynecology, Jeonbuk National \nUniversity, Jeonju, Republic of Korea\n2 Department of Obstetrics and Gynecology, Women and \nChildren’s Hospital of Chongqing Medical University, \nChongqing, China\n3 Department of Obstetrics and Gynecology, Chongqing \nHealth Center for Women and Children, Chongqing, China\n4 Chongqing Research Center for Prevention & Control of \nMaternal and Child Diseases and Public Health, Chongqing, \nChina\n5 Department of Biomedical Sciences, Institute for Medical \nScience, Jeonbuk National University Medical School, \nJeonju, Republic of Korea\n6 Department of Critical Care Medicine, Shandong Provincial \nHospital, Shandong First Medical University, Jinan, China\n7 The Geographical Indication Medicines and Life Health \nEngineering Research Center of Henan Province, Luoyang \nPolytechnic, Luoyang, China\n8 Research Institute of Clinical Medicine of Jeonbuk National \nUniversity- Biomedical Research Institute of Jeonbuk \nNational University Hospital, Jeonju, Republic of Korea\n9 Department of Obstetrics and Gynecology, Biomedical \nResearch Institute, Research Institute of Clinical Medicine of \nJeonbuk National University, Jeonbuk National University \nHospital, Jeonbuk National University Medical School, 20, \nGeonji-ro, Deokjin-gu, Jeonju 561-712, Jeonbuk, Republic of \nKorea\n10 Research Institute of Clinical Medicine, Jeonbuk National \nUniversity Medical School, 20, Geonji-ro, Deokjin-gu, \nJeonju 561-712, Jeonbuk, Republic of Korea\n1 3\n  138  Page 10 of 10","source_license":"CC0","license_restricted":false}