Comparison of perioperative outcomes between laparoscopy and robotic-assisted surgery in the surgical treatment of endometriosis: a retrospective study

Endometriosis, Minimally Invasive Surgery, Laparoscopy, Robotic Surgery, Perioperative Outcomes Posted Date: September 1st, 2026 DOI: https://doi.org/10.21203/rs.3.rs-10729934/v1 License:   This work is licensed under a Creative Commons Attribution 4.0 International License.   Read Full License Page 1/11 Additional Declarations: No competing interests reported. Version of Record: A version of this preprint was published at Journal of Robotic Surgery on September 28th, 2026. See the published version at https://doi.org/10.1007/s11701-026-03973-7. Page 2/11

Objective To compare perioperative outcomes between laparoscopy and robotic-assisted surgery in the surgical treatment of endometriosis in a high-volume tertiary center.

Retrospective, observational, and analytical study, including patients who underwent minimally invasive surgery for the treatment of endometriosis at Einstein Hospital Israelita between 2018 and 2022. A total of 520 patients were included, with 260 patients in each surgical group. Outcomes evaluated included surgical time, anesthetic time, length of hospital stay, estimated blood loss, intraoperative complications, need for intensive care, conversion to laparotomy, and early readmission.

Demographic characteristics were similar between the groups. Robotic-assisted surgery was associated with significantly shorter operative and anesthetic times, in addition to shorter hospital stays, when compared to laparoscopic surgery. There was no statistically significant difference between the approaches in terms of complication rates, surgical conversion, need for intensive care, blood transfusion, or early readmission.

Both approaches demonstrated a similar safety profile in the surgical treatment of endometriosis. Robotic-assisted surgery showed greater perioperative efficiency in a center with a mature learning curve, suggesting a potential advantage in highly complex scenarios.

Endometriosis is a chronic and benign gynecological disease that affects approximately 10% of women in reproductive age and is associated with chronic pelvic pain, dysmenorrhea, dyspareunia, and infertility, with possible significant impact on quality of life [1–4]. Surgical treatment is indicated in cases who are refractory to clinical management or in the presence of specific complications, and minimally invasive surgery occupies a space as the gold standard treatment, especially in the more advanced stages of the disease [5–8]. Laparoscopic Surgery (LS) has established itself as a consolidated approach in the surgical treatment of endometriosis because it has proved, along the years, visualization enhancement, lower morbidity, and Page 3/11 faster recovery when compared to laparotomy. More recently, robotic-assisted laparoscopic surgery (RALS) has been incorporated as an alternative tool for complex gynecological procedures, offering technical advantages such as three-dimensional vision, greater instrumental dexterity, and improved ergonomics [9–11]. However, the literature still presents conflicting results regarding the perioperative benefits of robotic- assisted surgery in the treatment of endometriosis, particularly in relation to surgical time, anesthetic time, and hospital stay. Initial studies often associated RALS with longer operative duration, mainly attributed to docking time and logistical limitations of the platform [10–12]. On the other hand, data from centers with high surgical volume and a mature learning curve suggest that these differences can be minimized or even reversed with the maturity of the robotic program. Considering the importance of this pathology and the impact on the quality of life of patients, the

of this study was to compare the perioperative outcomes of surgeries performed for the treatment of endometriosis via laparoscopy versus robot-assisted laparoscopic surgery in a solid and mature robotic center, in order to improve the care provided to patients at the institution.

This retrospective observational study was based on the review of electronic medical records of patients who underwent minimally invasive surgery for the treatment of endometriosis at Einstein Hospital Israelita (EHI), from 2018 to 2022. Patients who underwent surgical procedures by laparoscopic surgery or by robot-assisted surgery with indication for endometriosis treatment were included. After approval by the Research Ethics Committee of the institution, the eligible medical records were identified by the surgery department and the data were collected in an anonymized manner through the REDCap platform. The sample selection was carried out in a balanced manner, with 260 patients in each surgical group, using a random selection process to avoid selection bias. The medical records were reviewed for compliance with the inclusion criteria before the final analysis. The variables analyzed included demographic and clinical characteristics, surgical time, anesthetic time, length of hospital stay, estimated blood loss, need for transfusion, use of intensive or semi-intensive care unit, intraoperative complications, conversion to laparotomy, surgical reapproach, and early readmission. For the calculation of the sample size expected for statistical significance, a p < 0.05, a mean standard deviation of 58 populations, and an error of 5% were considered, as based on the article from Ádám Csirzó et al. (2023). Thus, we analyzed 520 medical records, equally distributed between the two surgical approaches. Page 4/11 Statistical Analysis The data were described for the general sample and by two groups, which were formed by type of surgical technique for endometriosis treatment (laparoscopy and robot-assisted laparoscopy), using absolute and relative frequencies for qualitative variables and measures such as median, mean, standard deviation, quartiles, minimum and maximum for quantitative variables. To compare the outcomes between the groups, association analyses were performed between qualitative variables, where chi-square tests were performed (Agresti, 2007), Fisher's exact tests (Agresti, 2007) or likelihood ratio tests (Agresti, 2007) depending on the variables that were compared. Also, to compare quantitative variables, their distributions were tested with Shapiro-Wilk normality tests (Altman & Matthews, 1996), for which all the quantitative variables tested rejected normality and, subsequently, Mann-Whitney tests were performed (Altman & Matthews, 1996) to compare the distribution between the groups. For the construction of boxplots in the visualization of quantitative variables to verify the differences between the groups, the variables were transformed with logarithm due to the large number of discrepant points. The analyses were carried out with the aid of the R program (R Core Team, 2021) and considering a significance level of 5%.

We retrospectively analyzed 520 medical records of patients who underwent surgical treatment for endometriosis at the EHI between 2018 and 2022, 260 of whom underwent conventional laparoscopy (LS) and 260 underwent robotic-assisted surgery (RALS). The sample was balanced, with 260 patients in each group.   Sociodemographic characteristics were similar between the LS and RALS groups. The mean age was 36.7 ± 7.1 years in the LS group and 36.5 ± 7.9 years in the RALS group (p = 0.538). The mean body mass index was also similar between the groups (24.5 ± 4.3 kg/m² in LS versus 24.4 ± 4.3 kg/m² in RALS; p = 0.801). Regarding marital status, most patients in both groups were married (63.5% in the LS group and 61.0% in the RALS group), followed by single patients (24.2% and 26.6%, respectively), with no statistically significant difference between the distributions (p = 0.801). Likewise, no significant differences were observed in terms of ethnicity, although a high proportion of unreported data in both groups stands out.  Significant differences were observed in the surgical history and habits of the patients (Tables 1 and 2). Patients undergoing RALS reported a higher proportion of previous laparotomic surgeries (29.5%) compared to the LS group (18.3%). On the other hand, the LS group reported a higher incidence of previous laparoscopic surgeries (20.8%) compared to the RALS group (12.7%). Patients in the LS group had a significantly higher rate of prior surgery for endometriosis (18.1%) compared to the RALS group (5.8%). Regarding the clinical comorbidities evaluated, no statistically significant differences were observed between the groups submitted to laparoscopic and robotic surgery. Page 5/11 There was a significant difference in the nature of the procedures performed between the groups. Resection of endometriosis foci combined with other procedures was more prevalent in LS (50.4%), whereas the RALS group had a higher proportion of procedures involving resection of endometriosis foci (71.2%). This association is detailed in Table 3. Regarding main perioperative outcomes, including operative time, anesthetic time, and length of hospital stay, there were statistically significant differences between the approaches (Table 3). Mean surgical time (ST) (in minutes) was significantly shorter in the RALS group (137.2 ± 131.9 min) compared to the LS group (152.7 ± 96.2 min). Similarly, Mean anesthetic time (AT) (in minutes) was significantly shorter in the RALS (177.7 ± 106.4 min) compared to the LS (201.0 ± 104.9 min). Postoperative length of stay (LOH) (in hours) was also significantly shorter for the RALS group (mean of 38.7 hours) compared to the LS group (mean of 50.2 hours). By isolating only patients whose main diagnosis in the anatomopathological examination was endometriosis, these trends were maintained: all surgical times, anesthetic, and hospital stay were significantly lower in the RALS (Table 4). In order to analyze more specifically the outcomes of the two approaches and to reduce confounding bias, a comparison was made considering only surgeries for resection of endometriosis foci without association with other procedures, whether gynecological or non-gynecological. An association was found between the technique used and the new procedure classification: 51.9% (135) of the patients with endometriosis who underwent robot-assisted surgery and 35% (91) of those operated by laparoscopic did not undergo any other procedure in the same surgical procedure. The p- value observed was < 0.001, highlighting a significant association between the variables. With significant p-values, surgery (in minutes) and anesthesia (in minutes) length were statistically different according to the technique performed, all shorter in the robot-assisted pathway. As for the postoperative length of stay and the amount of blood loss, there is no evidence of an association between the variables and the technique (Table 5). An additional analysis was also conducted with the aim of reducing bias introduced by the performance of non-gynecological procedures during the same surgical time. Only the 487 patients who underwent gynecological procedures were evaluated (242 in the LS group and 245 in the RALS group), excluding those who underwent other non-gynecological procedures at the same time. The results of this analysis corroborate the previous findings: mean surgical time was significantly shorter in the RALS group (131.2 min) compared to the LS group (150.9 min; p < 0.001), as was mean anesthetic time (171.4 min vs. 200.0 min; p < 0.001). Postoperative length of stay was also significantly shorter in the RALS group (mean of 40.0 hours vs. 53.6 hours in the LS group; p = 0.011). No statistically significant differences were observed between the groups regarding estimated blood loss, need for intensive care unit admission, early readmission, or intraoperative complications, reinforcing the equivalent safety profile between the approaches in this more homogeneous population. Page 6/11 Regarding safety outcomes, the analysis of the aggregate variable of "some intraoperative complication" (bladder injury, ureteral injury, intestinal injury, vascular trauma, postoperative bleeding, infection, vaginal dome dehiscence, sepsis, and conversion to laparotomy) did not show a significant association with the surgical technique (Table 6). The use of Intensive Care Unit (ICU) or Semi-Intensive Care Unit was rare in both groups (LS: 1.9%; RALS: 0.4%), with no statistical significance. As well as conversion to laparotomy, which occurred in 1 case (0.4%) in LS and in 0 cases (0.0%) in RALS (Table 5). There was no statistically significant difference in estimated blood loss (RPE) between the groups (LS: 82.2 mL; RALS: 55.6 mL). In the subgroup of patients with endometriosis, the result was also not significant. Regarding readmission rate, it occurred in 5.0% in the LS and 3.1% in the RALS, also with no statistical difference.

The main objective of this study was to compare the perioperative outcomes between laparoscopic surgery (LS) and robotic-assisted surgery (RALS) in the treatment of endometriosis at a referral center, Einstein Hospital Israelita over five years. The main findings demonstrate that both approaches had a similar safety profile, with low complication rates, surgical conversion, and early readmission. However, the RALS was associated with greater perioperative efficiency, as evidenced by significantly shorter surgical, anesthetic, and hospital length of stay. Minimally invasive surgery is widely recognized as the gold standard for the surgical treatment of endometriosis, especially in more complex cases, in which complete resection of the lesions requires high technical precision and anatomical preservation [10]. Although the robotic platform was, in its early years, used to be associated with longer operative time, especially during its implementation phase, more recent evidence suggests that this alleged disadvantage can be overcome by consolidating the learning curve and standardizing intraoperative flows. The results of this study contrast with much of the previus literature, which describes longer surgical duration associated with RALS compared to LS [10–12]. Traditionally, the increase in operative time in robotic surgery has been attributed to docking time, the need for specific instrumentation, and logistical

in extensive or extrapelvic procedures. In some studies, docking time alone exceeded 10 to 15 minutes [11]. In the present study, however, RALS demonstrated superior temporal performance, suggesting that, in a mature and solid robotic program and institution, these logistical factors become less relevant in the face of the technical advantages of the platform. The shorter operative time observed may be related to multiple institutional factors, including high surgical volume, consolidated experience of the surgical, anesthetic and multidisciplinary teams, standardized surgical protocols, and efficient integration between team and technology. The three- dimensional vision, tremor filtration, and greater freedom of movement provided by the robotic platform can favor more precise and faster dissections, particularly in scenarios of deep endometriosis or anatomy distorted by adhesions [11]. Another relevant finding was the significant reduction in the length of hospital stay in the group undergoing RALS. This result differs from some previous reports, in which Page 7/11 robotic-assisted surgery was associated with longer hospital stay [12]. In the context evaluated, this difference may reflect the adoption of accelerated recovery protocols, the shorter duration of the procedure, and the early clinical stability of patients undergoing RALS, favoring early hospital discharge with no negative impact on safety outcomes. Although these results point to a clear advantage of the RALS in the institutional context evaluated, their interpretation requires careful consideration of the methodological barriers of the present study. Regarding safety, no statistically significant differences were observed between the approaches in terms of the rate of intraoperative complications, need for transfusion, use of intensive care unit, or conversion to laparotomy. These findings reinforce that both LS and RALS are safe approaches for the surgical treatment of endometriosis when performed in specialized centers, corroborating previously published data and reinforcing the space of laparoscopy, which is still an important tool in the treatment of endometriosis. [10–12]. This study has limitations inherent to its retrospective and observational design, which prevents complete control of potential selection biases and confounding factors. Although the sample was balanced between the groups, the absence of detailed information on the severity of endometriosis, classification of lesions, and long-term clinical follow-up limits the evaluation of outcomes such as disease recurrence, pain control, fertility, and quality of life. In addition, the institution's open clinical staff model makes it difficult to access outpatient and follow-up data recorded outside the institutional medical record. Despite these limitations, the results related to immediate perioperative outcomes were robust and allowed safe comparisons between the two surgical approaches. Robotic-assisted surgery for the treatment of endometriosis demonstrated safety comparable to laparoscopic surgery, but with remarkable superiority in efficiency, evidenced by shorter surgical and anesthetic times, and shorter hospital stay. These findings suggest that, after the learning curve has been overcome by the surgical and room team, RALS may offer a real advantage in optimizing perioperative outcomes compared to LS in endometriosis procedures. The robotic platform, with its improved ergonomics and capabilities (3D vision and increased dexterity), (11) has the potential to not only enable more surgeons to perform complex minimally invasive surgeries, but also to increase temporal efficacy in centers with high experience by challenging the assumption that RALS is inherently associated with longer operative times between RALS and longer operative time. Prospective randomized studies focusing on cost-effectiveness and long-term outcomes are needed to consolidate the optimal indication of RALS versus LS in the setting of endometriosis.

In conclusion, RALS provides similar perioperative outcomes in safety to LS, but was associated with significant superior efficiency metrics in the experience of a mature high-complexity center, in addition to providing greater ergonomic advantages and technical precision. Although cost and long-term outcomes Page 8/11 (such as recurrence or fertility preservation) were not evaluated in this retrospective study, the use of RALS should be considered a highly competitive option for the treatment of endometriosis, especially in potentially more complex cases, and should be optimized and matured in tertiary centers to maximize its efficiency. Additional prospective studies are needed to assess cost-effectiveness and confirm these findings in different settings. Declarations Funding The authors declare that there was no receipt of funding, scholarships, grants or any other type of financial support for the conduct of this study. Conflicts of Interest The authors declare that they have no financial or non-financial conflicts of interest related to the content of this manuscript. Ethical Approval This retrospective study was conducted in accordance with the principles of the Declaration of Helsinki. The project was approved by the Research Ethics Committee of the Einstein Hospital Israelita. Consent to Participation Due to the retrospective nature of the study and the use of anonymized data, individual informed consent was waived by the Research Ethics Committee of the institution. Consent to Publication Not applicable. This study contains no identifiable patient data. Data Availability The data supporting the findings of this study are not publicly available due to institutional constraints related to the confidentiality of medical records but may be made available upon reasonable request to the corresponding authors and after institutional approval. Authors' Contributions All authors contributed to the conception and design of the study. Data collection and analysis were carried out by the authors. The writing of the manuscript was carried out by the authors, who critically reviewed the intellectual content and approved the final version submitted. Page 9/11

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