Abstract
Background:
This study evaluated the clinical performance and learning curve of the da Vinci Xi robotic laparoendoscopic single-site surgery (R-LESS) in gynecology by analyzing a consecutive series of 221 cases from a single tertiary center in mainland China.
Methods:
We retrospectively analyzed the medical records of patients who underwent R-LESS using the fourth-generation da Vinci Xi system in the Department of Gynecology, Zhongnan Hospital of Wuhan University, between January 2020 and January 2022. Clinical characteristics, operative time, estimated blood loss (EBL), intraoperative and postoperative complications, postoperative 24-hour visual analog scale (VAS) pain scores, time to bowel recovery, postoperative length of stay (LOS), hospitalization costs, and learning curves were analyzed.
Results:
A total of 221 patients were included, including 189 benign cases and 32 malignant cases. Benign indications included uterine leiomyoma and adenomyosis (n = 70), cervical lesion (n = 20), endometrial lesions (n = 9), uterine prolapse (n = 6), hydatidiform mole (n = 2), and adnexal masses (n = 82). All malignant cases were endometrial cancer (FIGO stage IA: n = 19; IB: n = 7; II: n = 6). Surgical procedures included robotic single-site total hysterectomy (n = 67), myomectomy (n = 40), ovarian cystectomy (n = 82), and staging surgery for endometrial cancer (n = 32). All operations were successfully completed without conversion to multiport laparoscopy or laparotomy. Perioperative outcomes were as follows:
(1) Total hysterectomy: operative time 115.95 ± 31.96 min, EBL 58.75 ± 22.48 mL, LOS 4.26 ± 0.93 days, 24-h VAS 1 (1–3); (2) myomectomy: operative time 113.17 ± 41.08 min, EBL 53.16 ± 22.63 mL, LOS 3.83 ± 0.99 days, 24-h VAS 1 (1–3); (3) ovarian cystectomy: operative time 85.16 ± 27.46 min, EBL 31.62 ± 19.14 mL, LOS 3.83 ± 1.15 days, 24-h VAS 1 (1–3); (4) malignant staging surgery: operative time 205.09 ± 56.05 min, EBL 111.50 ± 58.43 mL, LOS 5.75 ± 1.53 days. No intraoperative complications occurred. Postoperative complications were minimal, with one case of urinary retention after hysterectomy in the benign cohort and one infection after staging surgery in the malignant cohort. Learning curve analysis showed that proficiency was achieved after 12 cases for hysterectomy, 13 cases for adnexal mass surgery, 14 cases for myomectomy, and 17 cases for malignant staging surgery.
Conclusions:
This consecutive case series demonstrates that da Vinci Xi R-LESS is safe and feasible in gynecologic practice, with low blood loss, short hospital stay, and rapid postoperative recovery. Surgeons experienced in conventional laparoscopy can achieve proficiency within a relatively short learning curve.
Keywords: consecutive case series, da Vinci Xi robotic surgery, gynecologic surgery, learning curve, single-site laparoscopy
Introduction
Single-site laparoscopy has gained increasing attention in gynecologic surgery due to its advantages of rapid postoperative recovery, minimal scarring, and high patient acceptance. However, its widespread adoption has been limited by the “chopstick effect,” which restricts instrument mobility and increases operative difficulty[1]. Since the U.S. Food and Drug Administration approved the da Vinci robotic surgical system for gynecologic application in 2005[2], robotic-assisted surgery has expanded rapidly in this field, supported by its intuitive operation, short learning curve, and accelerated surgeon skill acquisition.
HIGHLIGHTS
The first consecutive cohort in mainland China evaluating the application of da Vinci Xi robotic laparoendoscopic single-site surgery (R-LESS) in gynecology.
R-LESS in gynecology has a short learning curve.
Surgeries with high technical complexity are more likely to benefit from R-LESSs.
The fourth-generation da Vinci Xi system was introduced in mainland China in 2019. Its integrated endoscopic platform, reduced instrument diameter (as small as 8 mm), enhanced high-definition three-dimensional visualization, and 540° wristed instruments – combined with tremor filtration and motion-scaling technology – enable greater operative precision and reduced surgical trauma. These improvements have driven substantial interest and rapid adoption within Chinese surgical practice.
Despite the growing clinical use of the da Vinci Xi system, reports on its application in robotic laparoendoscopic single-site surgery (R-LESS) for gynecologic procedures in China remain limited[3]. Therefore, this study aimed to evaluate the clinical performance, safety, and learning curve of the da Vinci Xi R-LESS approach using data from a single-center retrospective consecutive case series. The findings may provide evidence supporting its broader implementation in gynecologic surgery in mainland China.
Patients and methods
We retrospectively collected clinical and pathological data from patients who underwent robotic-assisted single-site laparoscopic gynecologic surgery (R-LESS) using the da Vinci Xi surgical system (Intuitive Surgical, USA) in the Department of Gynecology, Zhongnan Hospital of Wuhan University, between January 2020 and January 2022. Staging of malignant tumors followed the 2014 International Federation of Gynecology and Obstetrics (FIGO) classification. This study was conducted in accordance with the Reporting Guidelines[4]. Patients were informed of the advantages and disadvantages of robotic approaches in detail before the operation and made choices based on their own situations. Our study was registered with ResearchRegitry.com. Written informed consent was obtained from all patients for their data to be used for research purposes. The study was approved by the Ethics Committee of Zhongnan Hospital of Wuhan University (Approval No. XX). This work has been reported in line with the STROCSS criteria[5].
Inclusion criteria and exclusion criteria
Patients were eligible for inclusion if they met the following criteria: (1) age 18–65 years; (2) type of surgery: A. ovarian cystectomy: maximum cyst diameter < 10 cm; B. total hysterectomy: uterine size < 12 gestational weeks; C. myomectomy: maximum fibroid diameter < 10 cm and number of fibroids ≤ 3; D. malignant surgery (endometrial cancer staging): preoperative endometrial biopsy confirming endometrial carcinoma, with imaging showing disease confined to the uterus; patients were clinically diagnosed as FIGO 2018 stage I or II prior to surgery. Patients were excluded if they met any of the following conditions: (1) presence of significant comorbidities, including hepatic or renal dysfunction; (2) pregnancy or lactation; (3) diagnosis of malignancy at another anatomical site; (4) severe pelvic or abdominal adhesions detected intraoperatively; (5) requirement for concomitant non-gynecologic procedures during surgery; (6) for malignant cases undergoing endometrial cancer staging surgery: extensive intraperitoneal dissemination identified intraoperatively, or low-risk endometrial cancer cases in which lymphadenectomy was not performed.
Surgical procedures
All surgeries were performed by the same attending surgeon and team using the fourth-generation da Vinci Xi robotic surgical system. Patients were placed in the lithotomy or supine position, followed by standard surgical preparation and draping. The robotic cart was positioned between the patient’s legs and docked to the single-site platform (Fig. 1A). A 2–3-cm vertical umbilical incision was made, through which the single-site access platform (Kangji, Hangzhou, China) (Fig. 1B) was inserted. Pneumoperitoneum was established at 13–15 mmHg (1 mmHg = 0.133 kPa), after which the planned procedure was performed following standard operative steps.
Figure 1.
Single-site port and robotic instrument arrangement. A. Single-site access port. B. Configuration of robotic instrument docking.
The specific different surgical procedures were categorized as follows: (1) benign gynecologic surgery: total hysterectomy (with or without bilateral salpingo-oophorectomy), myomectomy, and ovarian cystectomy; (2) malignant gynecologic surgery (endometrial cancer staging): extrafascial total hysterectomy with bilateral salpingo-oophorectomy and pelvic lymphadenectomy, with or without para-aortic lymph node dissection. For FIGO stage II disease, modified radical hysterectomy with bilateral salpingo-oophorectomy and pelvic lymphadenectomy ± para-aortic lymph node dissection was performed.
Postoperative management
The criteria for drain removal were a drainage volume of less than 50 mL for two consecutive days. Postoperative discharge standards were formulated according to the Enhanced Recovery After Surgery guidelines for gynecologic procedures. Basic discharge requirements included: tolerance of a semi-liquid diet, discontinuation of intravenous fluids, adequate pain control with oral analgesics, satisfactory wound healing without signs of infection, stable organ function, and the ability to ambulate independently. Individualized discharge decisions were made based on each patient’s clinical condition and postoperative recovery status.
Observation indicators
All robotic procedures were performed by a senior gynecologic surgeon with extensive experience in single-site laparoscopy. The following perioperative indicators were collected and analyzed: operative time, defined as the interval from umbilical skin incision to completion of skin closure; estimated blood loss (EBL), calculated as the total intraoperative blood loss (EBL = suction bottle volume + gauze/dressing absorption; suction volume jointly assessed by the surgeon and anesthesiologist; blood absorption estimated as approximately 20 mL per fully soaked large gauze and 10 mL per small gauze); conversion rate to multiport laparoscopy or laparotomy; number of lymph nodes removed (for malignant cases); postoperative length of stay (LOS) and total hospitalization duration; duration of postoperative urinary catheterization; duration of drain placement; time to first flatus; change in hemoglobin level, comparing preoperative and postoperative values; postoperative 24-hour visual analog scale (VAS) pain score; requirement for blood transfusion; postoperative complications, including incisional hernia, urinary retention, bowel obstruction, and others; follow-up outcomes at 3–6 months postoperatively, assessed via telephone or outpatient visits to evaluate recovery status.
Cumulative sum analysis and learning curve modeling
For cumulative sum (CUSUM) analysis[6], all cases were ordered chronologically according to the sequence of surgery. The CUSUM value for the first case (CUSUM₁) was calculated as the difference between the operative time of the first case (OT₁) and the mean operative time of all cases (OT_mean): CUSUM₁ = OT₁ − OT_mean. For subsequent cases, the CUSUM value was calculated cumulatively as: CUSUMn = (OTn − OT_mean) + CUSUMn−1, until the final CUSUM value returned to zero.
For learning curve modeling, operative sequence was plotted on the x-axis and corresponding CUSUM values on the y-axis to generate a scatter plot. Curve fitting was performed, and a model was considered statistically valid if P < 0.05. The goodness of fit was assessed using the coefficient of determination (R2), and the model with the highest R2 was selected as the optimal representation of the learning curve. The peak (turning point) of the fitted CUSUM curve was interpreted as the minimum number of cases required to overcome the initial learning phase. Accordingly, the learning process was divided into: (1) the learning and improvement phase, and (2) the proficiency or mastery phase.
Statistical analysis
All statistical analyses were performed using SPSS version 26.0 (IBM Corp., Armonk, NY, USA). Continuous variables with a normal distribution were expressed as mean ± standard deviation (x̄ ± s) and compared using the t-test. Non-normally distributed continuous variables were presented as median (minimum, maximum) and compared using the non-parametric rank-sum test. Categorical variables were expressed as number (percentage) and analyzed using the chi-square test or Fisher’s exact test when appropriate. A P-value < 0.05 was considered statistically significant.
Results
Baseline characteristics
A total of 221 patients were included in this study. Among them, 189 underwent surgery for benign conditions, including uterine leiomyoma or adenomyosis (n = 70), cervical lesions (n = 20), endometrial lesions (n = 9), uterine prolapse (n = 6), hydatidiform mole (n = 2), and adnexal masses (n = 82). Thirty-two patients were diagnosed with malignant disease, all of which were endometrial carcinoma, comprising 19 cases of FIGO stage IA, seven cases of stage IB, and six cases of stage II. Patient age, body mass index, clinical and pathological staging of malignant tumors, disease categories, and history of pelvic or abdominal surgery across different surgical types are summarized in Table 1.
Table 1.
Patient characteristics.
| Variables | Hysterectomy (67) | Ovarian cystectomy (82) | Myomectomy (40) | Malignant tumor surgery (32) |
|---|---|---|---|---|
| Age (years) | 50.96 ± 8.18 | 33.81 ± 12.59 | 38.42 ± 6.70 | 52.75 ± 8.71 |
| BMI (kg/m2) | 23.47 ± 3.01 | 21.82 ± 3.32 | 22.30 ± 3.48 | 24.40 ± 3.11 |
| History of abdominal surgery (N, %) | ||||
| Yes | 29 (43.3) | 22 (26.8) | 17 (42.5) | 15 (46.9) |
| No | 38 (56.7) | 60 (73.2) | 23 (57.5) | 17 (53.1) |
| Disease type | ||||
| Uterine diseases | ||||
| Uterine fibroids | 20 | / | 40 | / |
| Uterine adenomyosis | 10 | / | / | / |
| Cervical lesions | 20 | / | / | / |
| Endometrial lesions | 9 | / | / | / |
| Uterine prolapse | 6 | / | / | / |
| Hydatidiform mole | 2 | / | / | / |
| Adnexa disease | ||||
| Mature teratoma | / | 27 | / | / |
| Endometriotic cyst | / | 16 | / | / |
| Serous cystadenoma | / | 9 | / | / |
| Mucinous cystadenoma | / | 8 | / | / |
| Other benign cysts | / | 22 | / | / |
| Endometrial cancer | ||||
| Ia | / | / | / | 19 |
| Ib | / | / | / | 7 |
| II | / | / | / | 6 |
| Complications | ||||
| Hypertension | 7 | 0 | 3 | 5 |
| Cardiovascular diseases | 3 | 0 | 0 | 0 |
| Diabetes | 2 | 0 | 0 | 3 |
Perioperative outcomes
The perioperative outcomes of R-LESS gynecologic surgery are shown in Table 2. All 221 procedures were completed successfully. The postoperative outcomes of R-LESS gynecologic surgery are shown in Table 3. For R-LESS total hysterectomy, the mean operative time was 115.95 ± 31.96 min, with an EBL of 58.75 ± 22.48 mL. The LOS was 4.26 ± 0.93 days, and the 24-hour postoperative VAS pain score was 1 (1–3). For R-LESS ovarian cystectomy, the mean operative time was 85.16 ± 27.46 min, with an EBL of 31.62 ± 19.14 mL. The maximum diameter of the excised cysts measured 7.30 ± 2.90 cm. The LOS was 3.83 ± 1.15 days, and the 24-hour postoperative VAS pain score was 1 (1–3). For R-LESS myomectomy, the mean operative time was 113.17 ± 41.08 min, with an EBL of 53.16 ± 22.63 mL. The maximum diameter of the removed myomas was 5.38 ± 1.06 cm. The LOS was 3.83 ± 0.99 days, with a total hospital stay of 5.84 ± 1.43 days. The 24-hour postoperative VAS pain score was 1 (1–3). For R-LESS staging surgery for malignant tumors, the mean operative time was 205.09 ± 56.05 min, with an EBL of 111.50 ± 58.43 mL. The LOS was 5.75 ± 1.53 days. The mean number of lymph nodes retrieved was 15.72 ± 4.61. The 24-hour postoperative VAS score was 1 (1–3). The mean duration of drain placement was 112.32 ± 39.12 hours, and the mean duration of urinary catheterization was 57.12 ± 19.44 hours.
Table 2.
Perioperative operative outcomes of R-LESS gynecological surgery.
| Variables | Hysterectomy (67) | Ovarian cystectomy (82) | Myomectomy (40) | Malignant tumor surgery (32) |
|---|---|---|---|---|
| Operation time (min) | 115.95 ± 31.96 | 85.16 ± 27.46 | 113.17 ± 41.08 | 205.09 ± 56.05 |
| Estimated blood loss (mL) | 58.75 ± 22.48 | 31.62 ± 19.14 | 53.16 ± 22.63 | 111.50 ± 58.43 |
| Intraoperative complications | 0 | 0 | 0 | 0 |
| Conversion | ||||
| Multi-site laparoendoscopic | / | / | / | / |
| Open abdominal | / | / | / | / |
| Maximum diameter of cyst (cm) | / | 7.30 ± 2.90 | / | / |
| Maximum diameter of fibroids (cm) | / | / | 5.38 ± 1.06 | / |
| Removed fibroids | / | / | 1 (1,3) | / |
| Removed lymph nodes | / | / | / | 15.72 ± 4.61 |
Table 3.
Postoperative operative outcomes of R-LESS gynecological surgery.
| Variables | Hysterectomy (67) | Ovarian cystectomy (82) | Myomectomy (40) | Malignant tumor surgery (32) |
|---|---|---|---|---|
| Drainage tube indwelling time (h) | 56.40 ± 20.64 | 60.72 ± 38.24 | 54.48 ± 12.72 | 112.32 ± 39.12 |
| Urinary catheter indwelling time (h) | 34.56 ± 23.28 | 24.72 ± 4.08 | 24.48 ± 3.12 | 57.12 ± 19.44 |
| Anus exhaust time (h) | 45.60 ± 16.56 | 46.56 ± 15.36 | 36.20 ± 17.04 | 39.12 ± 16.56 |
| Length of hospital stay (d) | ||||
| Postoperative hospital stay (d) | 4.26 ± 0.93 | 3.83 ± 1.15 | 3.83 ± 0.99 | 5.75 ± 1.53 |
| Total hospital stay (d) | 7.00 ± 1.62 | 5.96 ± 1.45 | 5.84 ± 1.43 | 9.75 ± 2.79 |
| Intraoperative blood transfusion (N/%) | 0 | 0 | 1 (2.5) | 0 |
| Hemoglobin difference between preoperative and postoperative day 1 (g/dL) | 1.8 ± 0.9 | 2.0 ± 0.9 | 2.0 ± 1.2 | 1.6 ± 0.8 |
| Hemoglobin difference between preoperative and postoperative day 3 (g/dL) | 1.8 ± 1.1 | 2.0 ± 1.1 | 2.0 ± 1.2 | 2.1 ± 0.8 |
| VAS score 24 h after surgery | 1 (1,3) | 1 (1,3) | 1 (1,3) | 1 (1,3) |
| Postoperative complications (N/%) | 1 (1.5) | / | / | 1 (3.1) |
| Urinary retention | 1 | / | / | 0 |
| Postoperative infection | 0 | / | / | 1 |
| Lymphatic fistula | 0 | / | / | 0 |
| Reproductive tract fistula | 0 | / | / | 0 |
| Abdominal incision hernia | 0 | / | / | 0 |
| Hospital costs (¥) | 48 193.94 ± 6963.22 | 43 907.22 ± 7141.01 | 41 439.45 ± 3651.56 | 62 654.94 ± 9315.87 |
Surgical complications
No intraoperative complications occurred in any surgery. Following R-LESS total hysterectomy, one case of postoperative urinary retention was observed, with an incidence of 1.5%. No significant postoperative complications were reported in patients undergoing R-LESS ovarian cystectomy or myomectomy. Among patients who underwent R-LESS surgery for malignant tumors, one case of postoperative infection occurred, corresponding to an incidence of 3.1%. During postoperative follow-up, no cases of genitourinary fistula, lymphocele, or abdominal wall incisional hernia were identified.
Learning curve
With the increasing number of procedures performed, the operative time for R-LESS gynecologic surgery progressively decreased (Fig. 2). As shown in Fig. 3, the optimal fitting model for the learning curves of all surgical types performed with the fourth-generation da Vinci Xi robotic single-site system was a cubic polynomial. The best-fit regression equations were as follows: total hysterectomy: CUSUM = 142 + 52.71x − 2.5 × 2 + 0.02*x3 (x: case number; R2 = 0.926; P < 0.05); myomectomy: CUSUM = − 32.53 + 26.91x − 1.3 × 2 + 0.02*x3 (x: case number; R2 = 0.912; P < 0.05); ovarian cystectomy: CUSUM = 204 + 4.74x − 0.19 × 2 + 0.00131*x3 (x: case number; R2 = 0.894; P < 0.05); malignant tumor staging surgery (endometrial cancer): CUSUM = 66.5 + 7x + 3.07x2 − 0.13*x3 (x: case number; R2 = 0.934; p < 0.05). The peak points of the fitted CUSUM curves were reached at 12, 14, 13, and 17 cases, respectively. Accordingly, the learning curves of the da Vinci Xi robotic single-site system showed that surgical proficiency was achieved after 12 cases for total hysterectomy, 13 cases for ovarian cystectomy, 14 cases for myomectomy, and 17 cases for malignant tumor staging procedures. Beyond these thresholds, operative times decreased markedly and entered a plateau phase.
Figure 2.
Trend plot of operative time. A. Hysterectomy. B. Myomectomy. C. Ovarian cystectomy. D. Malignant tumor surgery.
Figure 3.
CUSUM analysis of R-LESS gynecological surgery. A. Hysterectomy. B. Myomectomy. C. Ovarian cystectomy. D. Malignant tumor surgery.
As shown in Table 4, comparison between the learning-improvement phase and the proficiency phase demonstrated that operative times and postoperative hospital stay were significantly reduced across all surgical types (P < 0.05). No significant differences were observed in intraoperative blood loss.
Table 4.
Comparison of perioperative indicators at different stages of the learning curve.
| Benign disease surgery group | Malignant disease surgery group | |||
|---|---|---|---|---|
| Variables | Hysterectomy | Myomectomy | Ovarian cystectomy | Malignant tumor surgery |
| Operation time (min) | ||||
| Learning stage | 149.17 ± 39.81 | 120.95 ± 22.81 | 96.35 ± 30.01 | 250.37 ± 37.36 |
| Mastery stage | 112.37 ± 31.49 | 95.90 ± 13.74 | 68.50 ± 21.50 | 164.33 ± 33.85 |
| P | <0.001 | 0.001 | <0.001 | <0.001 |
| Estimated blood loss (mL) | ||||
| Learning stage | 71.62 ± 45.91 | 58.76 ± 35.03 | 36.34 ± 20.76 | 125.00 ± 55.53 |
| Mastery stage | 50.39 ± 29.22 | 42.64 ± 22.53 | 30.43 ± 24.17 | 97.14 ± 45.36 |
| P | 0.149 | 0.136 | 0.441 | 0.520 |
| Postoperative hospital stay (d) | ||||
| Learning stage | 5.71 ± 0.52 | 6.02 ± 1.46 | 5.43 ± 1.24 | 7.67 ± 1.53 |
| Mastery stage | 402 ± 1.15 | 3.65 ± 0.77 | 3.74 ± 1.25 | 5.42 ± 1.16 |
| P | <0.001 | <0.001 | <0.001 | 0.014 |
Cost analysis
Total hospitalization costs included all expenses related to surgery, consumables, medications, laboratory testing, and diagnostic examinations. The results showed that the mean total hospitalization cost for R-LESS total hysterectomy was 48 193.94 ± 6963.22 CNY. The mean total cost for R-LESS ovarian cystectomy was 43 907.22 ± 7141.01 CNY. For R-LESS myomectomy, the total hospitalization cost averaged 41 439.45 ± 3651.56 CNY, while R-LESS malignant tumor staging surgery incurred a mean total cost of 62 654.94 ± 9315.87 CNY.
Discussion
To the best of our knowledge, this study represents the first consecutive case-series analysis from a tertiary medical center in mainland China describing the application of the da Vinci Xi robotic system for single-site laparoscopic gynecologic surgery[3]. Our findings demonstrate that multi-arm R-LESS is feasible and safe, characterized by low intraoperative blood loss, a low incidence of perioperative complications, and a short learning curve, thereby supporting its rapid adoption in clinical practice.
Recent studies have reported the use of the da Vinci Xi system for gynecologic procedures involving both benign disease[7,9] and malignancies[10,12], providing preliminary evidence of its safety in the gynecologic field. Nevertheless, the integration of the Xi system with laparoendoscopic single-site surgery is still at a relatively early developmental stage in China. In 2018, Jayakumaran et al[13] in the United States and Yoo et al. in Korea[14] described their early experiences with Xi-assisted single-site surgery for benign gynecologic disease and ovarian cancer. In their series, all 35 cases were successfully completed, although two cases (5.7%) required conversion to multiport robotic surgery and one intraoperative complication (2.9%) was reported. In our cohort, no intraoperative complications occurred, and the postoperative complication rates were 1.5% for robotic single-site hysterectomy and 3.8% for malignant disease staging procedures – both lower than those previously reported[15,16]. This difference may be attributable to the enhanced dexterity, improved arm articulation, and expanded operative workspace provided by the fourth-generation Xi platform. Overall, our findings further support the safety and feasibility of the da Vinci Xi system for single-site laparoscopic gynecologic surgery.
Benign hysterectomy remains one of the most common gynecologic procedures. In the present study, R-LESS hysterectomy was associated with an EBL of 58.75 ± 22.48 mL, which is lower than the 75 mL (20–300 mL) reported by Jayakumaran et al[13] and the 100.0 mL (10.0–1600.0 mL) reported by Chen et al[17]. The mean operative time of 115.95 ± 31.96 minutes was also shorter than that reported by Jayakumaran et al (132 minutes; 60–294 minutes)[13] and by Chen et al (183.6 ± 53.6 minutes)[17]. Korean researchers observed that operative time decreased sharply after the initial 10 cases[18]. As shown in Fig. 2A, the learning curve plateaued after approximately 12 cases, with operative time stabilizing at around 110 min. This relatively short learning curve may be attributed to the surgeon’s prior experience with robotic surgery, as well as the relatively modest uterine size of the patients included in the cohort.
For ovarian cystectomy, operative time and blood loss did not show significant improvement. This may be explained by the inherently lower procedural complexity, the cautious selection of early cases with relatively mild pathology, and the surgeon’s extensive experience with conventional single-site laparoscopy. Furthermore, the docking process for R-LESS surgery is more time-consuming and technically demanding in the initial phase, which may offset potential advantages. In contrast, R-LESS myomectomy resulted in significantly reduced intraoperative blood loss (P < 0.05). We believe this benefit is related to the technical challenges associated with intracorporeal suturing during traditional single-site laparoscopy. The articulated robotic instruments substantially improve suturing precision and efficiency, thereby enhancing hemostasis. Taken together, these findings suggest that R-LESS laparoscopy may offer particular advantages for procedures involving greater technical complexity or demanding suturing tasks – such as hysterectomy, myomectomy, and oncologic staging procedures. Consequently, careful preoperative patient selection is essential to maximize the benefits of the robotic platform.
Previous studies[19–21] have demonstrated that R-LESS for gynecologic malignancies is both safe and feasible, yielding satisfactory surgical outcomes. In the present study, we retrospectively analyzed early clinical data from 32 cases of gynecologic malignancies treated with the fourth-generation da Vinci Xi R-LESS platform at our center. When compared with published R-LESS series[19] (which generally report operative times ranging from 180 to 250 min and lymph node yields between 12 and 20 nodes), our findings were broadly comparable in terms of operative duration and lymphadenectomy yield. Relative to conventional single-site laparoscopy for endometrial cancer, R-LESS demonstrated no significant differences in operative time[22] or lymph node count[23]; however, it was associated with markedly reduced intraoperative blood loss[22] and a significantly shorter time to postoperative flatus[22]. These results suggest that fourth-generation da Vinci Xi R-LESS surgery is a safe and effective approach for gynecologic malignancies and may further facilitate enhanced postoperative recovery.
The learning curve is commonly defined as the number of cases required for a novice surgeon to achieve procedural stability. Owing to the “chopstick effect,” conventional single-site laparoscopy typically requires approximately 20 cases to overcome the initial technical challenges[24,25]. In contrast, robotic-assisted laparoscopy mitigates instrument crowding and restricted triangulation, resulting in a substantially shorter learning curve. A large Korean series published in 2020 involving 626 benign gynecologic R-LESS procedures demonstrated that operative times for robotic hysterectomy, myomectomy, and adnexal surgery significantly decreased after the first 10 cases[18], indicating that R-LESS is technically accessible and rapidly mastered. Interestingly, our findings are largely consistent with these observations and further support the notion that robotic single-site laparoscopy has a steep and favorable learning curve. For Xi-assisted single-site surgery in gynecologic malignancies, previous studies have reported that 19–30 cases are generally required to surpass the learning curve for robotic staging procedures[26]. In our cohort, however, operative time markedly decreased after 17 cases, which is slightly earlier than the thresholds reported in the literature. This advantage may be attributed to the surgeon’s substantial prior experience with single-site laparoscopy for malignant disease. This further indicates that R-LESS has a relatively steep learning curve; however, with advances in robotic platforms and the accumulation of surgical experience, there remains considerable potential for further shortening of this learning curve.
However, our study has several limitations. First, this was a single-center retrospective analysis, and all procedures were performed by one highly experienced surgeon with extensive expertise in single-site laparoscopic surgery. Therefore, the findings may not be generalizable to all surgeons; nonetheless, they may serve as a useful reference for surgeons with similar experience. Second, this study only provides preliminary evidence of short-term surgical outcomes and lacks long-term follow-up data, such as postoperative ovarian function after ovarian cystectomy, reproductive outcomes after myomectomy, and survival outcomes for malignant diseases. In addition, operative time in this study was not further stratified to include robot-specific components such as docking time.
Conclusion
As the first continuous case series in China reporting the use of the da Vinci Xi robotic system for single-site laparoscopic gynecologic surgery, our study demonstrates that fourth-generation da Vinci Xi robotic single-site surgery is both feasible and safe for gynecologic procedures. Notably, all operations were performed by a single senior gynecologic surgeon with extensive experience in single-site laparoscopy but without prior experience in robotic surgery. This provides valuable reference experience for developing countries worldwide – particularly those with large populations – regarding the implementation and early adoption of the da Vinci Xi robotic single-site surgical platform.
Acknowledgements
Not applicable.
Footnotes
Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
Contributor Information
Yanyan Liu, Email: liuyywhu@163.com.
Manwen Luo, Email: lmwlucy@foxmail.com.
Wei Zhang, Email: zw6676@163.com.
Ethical approval
The authors take full responsibility for all aspects of the research and ensure that any concerns regarding the accuracy or integrity of the work are thoroughly addressed. This study has been approved by the Ethics Committee of each center involved in this study.
Consent
Consent for publication was obtained from all the patients.
Sources of funding
This study was approved by the National Natural Science Foundation of China (Grant number: 82472676), The “Sharp Knife” Technology Breakthrough Project of Hubei Province (Grant number: 2023BAA016), and Major Science and Technology Project of Hubei Province (Grant number: 2023BCA002).
Author contributions
Conception and design: Y.Y.L., W.Z. Provision of study materials or patients: Y.Y.L., Y.K., M.W.L. Collection and assembly of data: Y.Y.L., Y.K., M.W.L. Data collection, analysis and interpretation: Y.Y.L., Y.K., M.W.L. Manuscript writing: Y.Y.L. Final approval of manuscript: all authors. Financial support: W.Z.
Conflicts of interest disclosure
No potential conflicts of interest were disclosed.
Research registration unique identifying number (UIN)
Our research is registered on the Research Registry, and the registration number is researchregistry11713.
Guarantor
Wei Zhang.
Provenance and peer review
Not commissioned, externally peer-reviewed.
Data availability statement
The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request. The data are not publicly available due to privacy and ethical restrictions.
References
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request. The data are not publicly available due to privacy and ethical restrictions.