Efficacy and safety of TU-LESS retroperitoneal lymphadenectomy with manipulator-free laparoscopic hysterectomy in endometrial cancer staging.

Patients were divided into experimental (TU-LESS-MFLH [ n  = 22]) and control groups (MLS-MFLH [ n  = 26]) according to the surgical type. There were no differences between the control and experimental groups with respect to age, BMI, or pathologic type, indicating good comparability of the groups (Table  1 ). Table  2 shows the clinicopathological features of the patients with SLN metastasis. Table 1 Baseline characteristics of patients Factor Experimental group ( n  = 22) Control group ( n  = 26) t/χ² P value Age (years) 55.91 ± 8.788 57.62 ± 8.251 −0.693 0.492 Body mass index (kg/m²) 24.27 ± 5.284 26.88 ± 3.362 −2.001 0.44 Pathologic types 0.3 0.766  Poorly differentiated adenocarcinoma 2 4  Moderately differentiated adenocarcinoma 17 19  Special types (serous and clear cell) 3 3 Staging −0.832 0.405  IA 5 5  IB 12 20  IIIA 1 0  IIIC 4 1 Baseline characteristics of patients Table 2 The clinicopathological featuresof patients with SLN metastasis Staging Age Pathologic types LVSI Tumor size (cm) IIIC 69 Moderately differentiated adenocarcinoma + 2.1 IB 42 Poorly differentiated adenocarcinoma + 3.6 IIIC 67 Special types (serous and clear cell) + 4.2 IIIC 55 Poorly differentiated adenocarcinoma + 1.8 IB 69 Moderately differentiated adenocarcinoma + 4.1 IIIC 58 Poorly differentiated adenocarcinoma + 2.5 IIIC 56 Special types (serous and clear cell) + 1.6 The clinicopathological featuresof patients with SLN metastasis No significant differences were detected in operative time, intraoperative blood loss, or the number of pelvic lymph nodes dissected between the two groups ( P  > 0.05). The number of para-aortic lymph nodes dissected was significantly higher in the experimental group than the control group ( P  < 0.05). No urinary or digestive tract or major vascular injuries and bleeding occurred intraoperatively. The postoperative hospital stay, gastrointestinal recovery time, and drainage tube and urinary catheter indwelling times were all significantly shorter in the experimental group than the control group ( P  < 0.05; Tables  3 and 4 ). The ascites cytologic findings in both groups were negative postoperatively. There were two patients in the experimental group and 1 patient in the control group with lymphovascular space invasion (LVSI); the three patients were comparable. No complications, including intraoperative organ injury, poor healing of the surgical incision, lymphocyst formation, a chylous fistula, urinary tract infection, and VTE, occurred in either group (Table  5 ). Table 3 Intraoperative data comparison Parameters Experimental group (n=22) Control group (n=26) t P value Operative time (min) 201.73 ± 82.453 163.85 ± 39.428 1.973 0.058 Intraoperative blood loss (ml) 36.82 ± 19.612 29.62 ± 10.763 1.538 0.134 Number of pelvic lymph nodes 33.77 ± 12.675 32.15 ± 11.681 0.457 0.650 Number of para-aortic lymph nodes 12.5 ± 8.331 7.73 ± 4.609 2.391 0.023 Intraoperative data comparison Table 4 Postoperative recovery parameters Parameter Experimental group ( n  = 22) Control group ( n  = 26) t P value Postoperative hospital stay (days) 4.55 ± 0.8 5.88 ± 1.608 −4.468 0.000 Gastrointestinal recovery time (days) 0.818 ± 0.2462 1.269 ± 0.4523 −4.376 0.000 Drainage tube retention time (days) 2.636 ± 1.1253 4.308 ± 1.4634 −4.468 0.000 Urinary catheter retention time (days) 1.705 ± 0.9343 2.923 ± 1.3243 −3.723 0.001 Postoperative recovery parameters Table 5 Postoperative complications and follow-up recurrence rates Parameters Experimental group ( n  = 22) Control group ( n  = 26) Intraoperative organ injury 0 0 Poor healing of the surgical incision 0 0 Positive pelvic and abdominal lavage fluid 0 0 Incisional hernia 0 0 Lymphatic cyst 0 0 Chylous fistula 0 0 Urinary tract infection 0 0 Venous thromboembolism Recurrence cases 0 0 Number of surviving cases 22 26 Postoperative complications and follow-up recurrence rates The cosmetic satisfaction score postoperatively was significantly higher in the experimental group than the control group ( P  < 0.05; Table  6 ). Table 6 Postoperative cosmetic satisfaction Groups n Very dissatisfied Dissatisfied Neutral Satisfied Very satisfied Mean rank Rank sum P value Experimental 22 0 0 0 13 9 34.55 760 0.000 Control 26 0 0 16 10 0 16 416 Postoperative cosmetic satisfaction The experimental group experienced significantly lower pain scores 24 h postoperatively than the control group, as evaluated based on the VAS ( P  < 0.05; Table  7 ). Table 7 VAS pain score 24h postoperatively Groups n Mean ± SD t P value Experimental 22 2.14 ± 0.834 −6.456 0.000 Control 26 3.73 ± 0.874 VAS pain score 24h postoperatively The levels of serum CA-125, CA-199, CEA, and HE4 were remarkably decreased in the experimental group compared to the control group 1 month postoperatively ( P  < 0.05; Table  8 ). Table 8 Postoperative tumor marker levels Markers Experimental group ( n  = 22) Control group ( n  = 26) t P value CA-125 (U/mL) 12.48 ± 1.79 16.17 ± 5.6 3.224 0.002 CA19-9 (U/mL) 3.19 ± 1.09 5 ± 2.86 3.048 0.004 CEA (ng/mL) 1.08 ± 0.04 1.78 ± 0.75 4.746 < 0.001 HE4 (µg/L) 1.12 ± 0.16 4.4 ± 7.07 2.361 0.022 Postoperative tumor marker levels There was no statistical significance in the incidence of incisional hernias, lymphatic fistulas, lymphatic cysts, chylous leakage, and urinary tract infections 3 months postoperatively between the two groups. The patients in the experimental group had significantly higher scores in the physical, cognitive, emotional, role, and social functioning dimensions of the FACT-G quality of life inventory 6 months after surgery ( P  < 0.05; Table  9 ). No recurrences had occurred in either group at the 24-month follow-up evaluation and the patients in both groups were in the tumor-free survival period. Table 9 Quality of life 6 months post-treatment Dimensions Experimental group ( n  = 22) Control group ( n  = 26) χ² P value Physical function 50.78 ± 2.69 43.29 ± 2.47 11.04 < 0.001 Cognitive function 60.22 ± 3.28 51.37 ± 2.29 12.07 < 0.001 Emotional function 51.59 ± 3.26 43.39 ± 2.57 10.72 < 0.001 Role function 59.23 ± 2.49 52.89 ± 2.47 9.687 < 0.001 Social function 52.92 ± 2.98 45.05 ± 2.13 11.71 < 0.001 Quality of life 6 months post-treatment

This was a retrospective cohort study that included 48 patients undergoing radical surgery for EC in the Gynecology Department of Meizhou People’s Hospital (Guangdong Province, China) from June 2022 to June 2023. The study was approved by the hospital Ethics Committee (No. 2024-C-93) and all patients provided written informed consent. Candidates were considered eligible if in compliance with the following criteria: 1) > 18 years of age; 2) a histopathologic diagnosis of EC; 3) tolerance to surgical treatment; 4) lesions ≥ 2 cm in size; 5) no cervical involvement and no intra-abdominal metastases; 6) indications for lymphadenectomy (deep muscular layer infiltration, positive pelvic lymph nodes, special pathologies [G3, serous adenocarcinoma, clear cell carcinoma, and carcinosarcoma], cervical involvement [stage II], and lesions extending beyond the uterus); and 7) no neoadjuvant therapy. Preoperative staging was performed using FIGO2009. The exclusion criteria were as follows: (1) diagnosed with endometriosis; (2) severe dysfunction of vital organs; (3) severe underlying medical conditions; (4) active infection; (5) extensive abdominal surgery history; (6) suspected multiple tumor metastases; and declined surgical treatment. Patients were divided into an experimental group (TU-LESS-MFLH treatment) and a control group (MLS-MFLH treatment). All surgeries were performed by the same surgical team. The primary operations were lymphadenectomy and MFLH. Venous thromboembolism (VTE) risk was assessed preoperatively and prophylaxis was provided with low-molecular-weight heparin and foot pump compression for at-risk patients. Vaginal irrigation was performed with 1% povidone-iodine. Patients underwent an 8-h fast with a 2-h fluid restriction without routine bowel preparation preoperatively. Prophylactic antibiotics were administered 30–60 min before the surgical procedure commenced. Patients were placed in the modified lithotomy Trendelenburg position under general anesthesia. Patients were prepped and draped in the usual fashion, a urinary catheter was inserted, and a second disinfection of the vagina and perineum was performed. Patients were placed in the lithotomy position with the surgeon on the patient’s right side. A 2.5–3.0 cm single-port vertical incision was made at the umbilicus (Fig.  1 A) and the subcutaneous tissue was bluntly dissected to access the abdominal cavity. A single-port device and wound protector were placed and CO₂ insufflation was initiated to maintain a pneumoperitoneum (12 mmHg) at a flow of 20 L/min. The laparoscope and accessory instruments were placed via the single port to view the abdominal cavity. Peritoneal washings were collected for cytology and the fallopian tubes (bilateral) were coagulated and transected with bipolar electrocautery. Fig. 1 Surgical procedure of transumbilical laparoendoscopic single-site surgery (TU-LESS) via retroperitoneal approach for lymphadenectomy and manipulator-free laparoscopic hysterectomy.  A  The 2.5–3.0 cm single-port vertical incision at the umbilicus; B  Elevation of peritoneum over the aortic bifurcation; C  Retroperitoneal puncture; D  Incision of the retroperitoneum and blunt dissection; E  Fixation of the retroperitoneum to the umbilical incision to form a closed space; F  Exposure the ureter and the course of the surrounding vessels; G  Para-aortic lymphadenectomy; H  Pelvic lymphadenectomy; I  Coagulation and transection of paracervical vessels; J  Vaginal wall suturing; K  Vaginal irrigation; L  Vaginal transection Surgical procedure of transumbilical laparoendoscopic single-site surgery (TU-LESS) via retroperitoneal approach for lymphadenectomy and manipulator-free laparoscopic hysterectomy.  A  The 2.5–3.0 cm single-port vertical incision at the umbilicus; B  Elevation of peritoneum over the aortic bifurcation; C  Retroperitoneal puncture; D  Incision of the retroperitoneum and blunt dissection; E  Fixation of the retroperitoneum to the umbilical incision to form a closed space; F  Exposure the ureter and the course of the surrounding vessels; G  Para-aortic lymphadenectomy; H  Pelvic lymphadenectomy; I  Coagulation and transection of paracervical vessels; J  Vaginal wall suturing; K  Vaginal irrigation; L  Vaginal transection The peritoneum over the aortic bifurcation was raised towards the umbilical incision with non-traumatic forceps (Fig.  1 B), exploration of the pelvic and abdominal cavities was completed, and the pelvic and abdominal cavity lavage fluids were collected. Then, the disposable incision protection sleeve was removed and the peritoneum (presacral) below the umbilical foramen was lifted to the outside of the abdominal cavity using vascular forceps. A small incision was made in the peritoneum and the pneumoperitoneum needle was inserted into the peritoneal incision (Fig.  1 C). The pneumoperitoneum needle was removed due to the water pressure effect after inflation and the peritoneal and sub-peritoneal tissues were bluntly separated by the surgeon’s fingers (Fig.  1 D). A silk thread was used to seal the peritoneal and umbilical incisions to form a closed space (Fig.  1 E). A disposable incision protective sleeve was placed and a single-hole finished kit was placed. The pneumoperitoneum pressure was maintained at 12mmHg and the abdominal inflation flow rate remained at 20 L/min. The ureter and the course of the surrounding vessels were exposed (Fig.  1 F) and an ultrasonic scalpel was used to remove the para-aortic lymph nodes between the abdominal aorta and the inferior vena cava and on the surface of the renal vein downward from the bifurcation of the abdominal aorta top-to-bottom (Fig.  1 G). The pelvic lymph nodes were removed and placed in a specimen bag. Pelvic lymphadenectomy was also completed at the same time (Fig.  1 H). Bipolar hemostasis and coagulation of lymphatic vessels and lymph node incisions were performed and the single-hole finished kits and protective sleeves were removed. The peritoneum and umbilical incision suture sites and the presacral peritoneum were continuously closed with absorbable sutures. Finally, a total hysterectomy without hysterectomy was performed. MFLH was then completed. No uterine manipulator or suspension suture was used during the MFLH procedure. The infundibulopelvic ligament was first retracted and the peritoneum between the ligament and the ureter was dissected. The round ligament and distal portion of the infundibulopelvic ligament were transected with bipolar cautery and an ultrasonic scalpel and the bilateral parametrial tissues were exposed. The anterior and posterior leaves of the broad ligament were then opened, the loose tissues around the uterus were freed, and the uterine arteries were coagulated and sealed (Fig.  1 I). The cardinal and uterosacral ligaments were transected and clamped close to the uterus. The uterus was drawn upward and the vesicouterine peritoneal fold was incised using an ultrasonic scalpel. The bladder was dissected inferiorly to a position approximately 1 cm below the external cervical os. The uterine serosal peritoneum was clamped for anteversion of the uterus. The rectouterine peritoneal fold was incised and the rectum was dissected downward to a level approximately 1 cm below the external cervical os. The vagina below the fornix was sutured with absorbable thread to seal the vaginal wall after completing separation of the parametrium, vesicle-cervical space, and rectouterine space (Fig.  1 J). The vaginal cavity was irrigated with 1% povidone-iodine solution (Fig.  1 K). A circular incision was made with a ultrasonic scalpel, the vaginal wall was secured below the suture (Fig.  1 L), and the uterus, adnexa, and lymph nodes were removed. The pelvic cavity was irrigated again with 1% povidone-iodine solution and sterile water. The vaginal cuff was closed with sutures. After ensuring complete hemostasis, a pelvic drain was placed and the abdominal incision was closed. Patients were placed in the lithotomy position. A vertical 1 cm incision was made just above the umbilicus and the pneumoperitoneum was established with carbon dioxide (CO₂). Intra-abdominal pressure was maintained at 12 mmHg and a flow at 20 L/min. A 1-cm trocar was inserted through the incision to secure the laparoscope. The second trocar was placed at McBurney’s point, the third trocar was placed at the left lower abdominal wall corresponding point, the fourth trocar was placed along the lateral one-third of the line between the umbilicus and the left anterior superior iliac spine (approximately 0.5 cm lateral), and the fifth trocar was placed at the lateral one-third of the line between the umbilicus and the right anterior superior iliac spine (approximately 1–1.5 cm lateral). All trocars measured approximately 5 mm in diameter. Laparoscopic instruments were inserted after insertion of the trocar. A preliminary examination was performed upon entry into the abdominal cavity and peritoneal fluid was aspirated for cytology. The two fallopian tubes were then coagulated and divided using bipolar electrocautery. The small bowel was mobilized to expose the peritoneum overlying the abdominal aorta. After incising the pelvic peritoneum, para-aortic, presacral, common iliac, internal iliac, external iliac, obturator, and inguinal lymphadenectomy was performed. Bagged specimens for retrieval bags were removed with resected lymph nodes. Total hysterectomy was performed with the same technique used in the experimental group. Baseline information (age, body mass index [BMI], and pathologic type) was documented prior to surgery to ensure the groups were comparable. The major outcomes were as follows: perioperative outcomes (operative time, intraoperative blood loss, intraoperative complications, and the number of lymph nodes dissected); and postoperative recovery (first anal exhaust, drainage tube removal time, length of hospital stay, postoperative complications, and visual analog scale [VAS] score 7 d postoperatively to quantify surgical efficiency, invasiveness, and safety). Secondary outcomes included the following: patient satisfaction with the surgical wound; reported quality of life; and 2-year disease-free survival (DFS) rate; and recurrence rate. The extent of lymphadenectomy was established by tallying the total number of pelvic and para-aortic lymph nodes dissected. Day 7 postoperative pain was evaluated by the VAS with scores ranging from 0 (no pain) to 10 (most severe pain). The preoperative serum levels of CA-125, CA-199, CEA, and HE4 were measured 1 month postoperatively using ELISA kits (Abbott Ireland Diagnostics, Ireland) to monitor tumor-related biomarkers. Urinary retention, lymphocyst formation, infection, VTE occurrence, and bleeding were recorded as complications. Quality of life was assessed 24 months after surgery using the Functional Assessment of Cancer Therapy–General (FACT-G) survey, which evaluates physical, emotional, social, and functional well-being. Short-term oncologic outcomes were established by comparing 2-year DFS and recurrence rates between the groups. EC patients were followed in accordance with the society recommendations. Monitoring of imaging, serology, and gynecologic examination findings was performed postoperatively to determine whether there were signs, such as tumor residue, recurrence, and lymphocyst formation. Statistical analysis was performed with SPSS (version 26.0). Categorical variables are expressed as frequencies and percentages and compared using a chi-square test. Continuous variables are expressed as the mean ± SD. An independent samples t-test was used for between-group comparisons and a paired t-test was used to compare pre- and post-treatment within groups. A P  < 0.05 was considered statistically significant.

The TU-LESS-MFLH allows for complete surgical staging in EC through a minimally invasive, single-incision technique, avoiding use of a uterine manipulator. TU-LESS-MFLH offers a balance of safety, surgical efficiency, and satisfactory cosmetic outcomes based on the 24-month follow-up results. However, multicenter studies with larger sample size, longer follow-up and better controlling of the confounding factors are necessary before drawing definitive conclusions. Further research is still needed to validate the effectiveness and safety of TU-LESS.

TU-LESS was shown to be a safe and effective method for patients with high-risk EC, yielding better recovery and cosmetic results, a good quality of life, and no recurrence or complications during 24 months of follow-up care. The short-term outcomes and safe perioperative results showed the potential of TU-LESS in EC patient treatment. Single-incision laparoscopic surgery, a typical example of new-generation minimally invasive procedures, offers benefits that include postoperative aesthetics, pain control, and speed of recovery. Specifically, the transumbilical approach utilizes camouflage anatomy and a low risk of contamination, thereby providing patients with an improved humanistic experience [ 12 ]. Several recent reports have documented that TU-LESS is safe, feasible, and advantageous in EC surgery [ 13 – 15 ], the results of which are consistent with the results of the current study. Deng et al. [ 13 ] compared TU-LESS with the “chopstick technique” and conventional MLS and reported that although a longer operative time was associated with TU-LESS, less postoperative pain and higher incision satisfaction was achieved with TU-LESS without altering blood loss, lymph node count, or perioperative complications, indicating comparable oncologic effectiveness and improved cosmetic outcomes. Similarly, You et al. [ 14 ] retrospectively compared TU-LESS and MLS and reported similar operative time and complication rates with TU-LESS patients ambulating sooner and having lower postoperative pain scores and no difference in 4-year overall survival (OS), categorizing TU-LESS as an effective, safe alternative to MLS. Lander et al. [ 15 ] demonstrated that patients with stage III EC who underwent lymphadenectomy following neoadjuvant chemotherapy had significantly improved OS, highlighting the central role of lymph node dissection in the management of advanced EC. Single-incision laparoscopic surgery has some disadvantages, such as limited visualization of the operating field, instrument crowding, and troublesome manipulation of complex anatomic structures. These disadvantages are even more noticeable in difficult procedures, like para-aortic lymphadenectomy. The standard transperitoneal approach is often compromised by bowel interference and restricted operative field, potentially affecting the thoroughness of lymph node dissection and safety of surgery, thus failing to achieve the “no tumor” criterion for high-risk EC patients [ 16 ]. The current study combined the use of retroperitoneal access based on the TU-LESS procedure with MFLH to establish an innovative surgical paradigm that is both anatomically sensible and operationally practicable and safe. The retroperitoneal route utilizes natural anatomic spaces maximally to directly access the para-aortic target zone and thus avoid bowel obstruction. Indeed, this approach maximizes exposure and completeness of lymphadenectomy at the renal vessel level with minimal peritoneal incisions to avoid intraoperative tumor seeding and postoperative adhesions [ 17 ]. The intraoperative blood loss was also optimally controlled with coordinated instrument usage [ 18 ]. The results herein showed that TU-LESS guarantees good quality lymph node clearance with successful management of perioperative complications [ 18 ]. In this review the baseline features of two groups of patients were compared and shown to have no differences in age, BMI, and medical history. The operative time and intraoperative blood loss were not significantly different between the two study groups, indicating that the retroperitoneal approach in TU-LESS surgery is equivalent to standard approaches [ 19 ]. The number of excised pelvic lymph nodes was similar between groups. however, the number of resected para-aortic lymph nodes in the TU-LESS retroperitoneal group was significantly higher than the control group, indicating the advantage of this approach in high-level lymphadenectomy [ 20 ]. The time of postoperative catheterization, first flatus time, drain removal, and hospital stay were decreased in the experimental group, reflecting a decreased postoperative recovery time [ 21 ]. No complications were noted intra- or post-operatively, which demonstrated the safety of TU-LESS. Furthermore, the MFLH method eliminated the risk of exfoliation and tumor cell dissemination associated with the application of a conventional manipulator. With the application of atraumatic clamping uterine traction, vaginal cuff closure, and intraoperative saline lavage, an integrated closed-loop system of tumor resection and prevention of dissemination was obtained that ensured surgical “cleanliness” and enhanced quality of life postoperatively. Such an approach is not only supported by cellular biology theory but also established in large clinical trials, such as SUCCOR, emphasizing the prophylactic advantage of the “no uterine manipulator” concept in oncologic minimal access surgery [ 22 ]. Measurement of postoperative pain showed that patients in the experimental group had significantly lower VAS scores compared to the control group, which suggests more effective pain control. Cosmesis of surgical wounds was also rated higher, suggesting less surface trauma and better aesthetic postoperative results in this group [ 23 ]. The experimental group had better postoperative recovery compared to the control group in the parameters of hospital stay, drain time of removal, and 24-h walking pain scores postoperatively. Patients were more satisfied at the 3-month follow-up evaluation with the cosmetic outcome of the incision, implying that patients’ psychological well-being and overall postoperative satisfaction as well as minimizing anatomic trauma are positively affected by this method, which suggests the direction of current gynecologic surgery toward an integration of function, aesthetics, and psychology in the surgical results [ 24 ]. Postoperative tumor marker comparison (CA-125, CA-199, CEA, and HE4) were significantly lower in the experimental group than the control group, suggesting increased tumor control. The experimental group did not differ significantly from the control group in pelvis lymph node yield but differed significantly in resected para-aortic lymph nodes ( P < 0.05). The two groups did not report any recurrences or complications during the 2 years of follow-up care. These results suggested the benefits and the short-term effectiveness of the retroperitoneal approach for high-level lymphadenectomy. This has a practical benefit for precise postoperative staging and future management planning in patients with high-risk EC [ 25 ]. Quality-of-life evaluations 24 months postoperatively demonstrated that the patients in the experimental group reported improved physical functioning, mental health, and social participation compared to controls and provide evidence for the long-term benefit of the technique in improving patient quality of life [ 26 ]. However, a 24-month follow-up is too short to demonstrate the long-term effects of TU-LESS. More research is needed to verify our results. It is remarkable that no false negatives were observed. This result may due to small sample size from one single center. So, the current results should be treated with caution, and multicenter studies with longer follow-up are necessary before drawing definitive conclusions. Moreover, no postoperative VTEs occurred in both groups. However, VTE remains a common and serious complication of EC surgery. The pathogenesis of VTE is multi-factorial, influenced by the operative duration, patient baseline condition, and intraoperative mobilization, which justifies future large-scale prospective studies to develop risk predictive models and tailored prevention approaches [ 27 ]. Previous evidence has indicated that procedures performed without the use of a uterine manipulator are effective in managing intraoperative blood loss and cause less physical trauma, hence enhancing physical outcomes. Procedures performed without the use of a uterine manipulator also avoid vaginal wall abrasions and uterine perforations, as well as complications. In addition, the absence of a uterine manipulator is also associated with no postoperative vaginal pain and faster recovery, hence further enhancing surgical efficacy [ 28 ]. Due to the small sample size in this study further research needs to be performed to confirm the safety of TU-LESS. In summary, the integrative surgical method with TU-LESS-MFLH balances accuracy, safety, and minimal invasiveness with higher clinical value in total lymph node dissection, quality of recovery after surgery, and tumor dissemination control. Although there is a learning curve for the procedure, operative time significantly decreases with experience, demonstrating satisfactory reproducibility and promising prospects for further spread. Subsequent studies should focus on the extrapolation of this technique to different EC risk levels, long-term follow-up for oncology, measurement of quality of life postoperatively, and institution of standardized multicenter training protocols. All these measures will enable this technique to be transitioned from a “technical breakthrough” to a “clinical consensus,” with outstanding support for advancing minimally invasive surgery in gynecologic malignancies [ 29 ]. There were several limitations to this study. First, the study was a retrospective single-center study with the absence of a comparator arm and a small sample size, which limited the stability and generalizability of the findings. Second, the wide range of participant ages (35–70 y) and the different sample size between the two groups might have introduced significant heterogeneity to the results. Because treatment-related complications and outcomes are influenced by age and BMI, the heterogeneity could decrease the representativeness and interpretability of the results. Third, the relatively short follow-up (24-month), which limits oncologic outcome interpretation and the proper assessment on the long-term oncologic outcomes, such as the 5-year survival rate and DFS period. Fourth, variability of surgical technique and surgeon experience were not adequately analyzed, which potentially influenced surgical outcomes. Lastly, subjective results, such as postoperative pain and quality of life, are influenced by patient-specific variables and psychological status. Therefore, the results from the current study need to be confirmed in future larger multicenter trials with more samples. Further research should control confounding factors, like age, BMI, and group setting to reduce the heterogeneity. A long follow-up > 5 y is recommended to more definitively compare survival and recurrence rates, and the quality of life among the patients. The incorporation of additional objective physiologic parameters and multidimensional evaluation instruments in future work will enhance the results.

Endometrial cancer (EC) is one of the most common gynecologic malignancies, the incidence and mortality rates of which have been steadily increasing over the past few years, predominantly in postmenopausal women [ 1 ]. Surgery remains the cornerstone of curative therapy and the basis for staging and planning subsequent adjuvant therapy [ 2 ]. Multi-port laparoscopic surgery (MLS), with the advances in minimally invasive surgical concepts, has become the optimal method for treating EC due to the low surgical trauma and quick recovery [ 3 , 4 ]. Lymph node metastasis is a critically significant prognostic variable in EC. While nodal spread is typically stepwise from the pelvis to the level of the para-aortic region, 12%–16% of patients demonstrate retroperitoneal skip metastases and 77% of para-aortic lymph node metastases are above the level of the inferior mesenteric artery [ 5 ]. There is significant variation in international guidelines in the surgical treatment of EC. East Asian guidelines suggest dissection to the level of the renal vessels, whereas Western guidelines often limit dissection to the level of the inferior mesenteric artery, potentially leading to understaging in approximately 21% of high-risk cases [ 5 ]. The retroperitoneal method of para-aortic lymphadenectomy has been adopted as a technique with better exposure and minimal manipulation of bowel and an integral part of minimally invasive gynecologic surgery [ 6 ]. The retroperitoneal approach can directly expose the pelvic and para-aortic lymph node regions, and offers a clearer field of vision [ 7 , 8 ]. Therefore, transumbilical laparoendoscopic single-site surgery (TU-LESS) via a retroperitoneal approach has emerged as a promising minimally invasive option [ 9 ]. TU-LESS via a retroperitoneal approach for lymphadenectomy has introduced a novel operative strategy. Specifically, single-incision umbilical access enables rapid establishment of a retroperitoneal working space with three-dimensional visualization and en bloc lymph node dissection at the level of the renal vessels, resulting in up to 29% greater efficiency in lymph node harvesting and reduced bowel disturbance [ 7 – 9 ]. Moreover, TU-LESS minimizes bowel interference and conceals scars in the abdomen [ 7 – 9 ]. Manipulator-free laparoscopic hysterectomy (MFLH) performed without a uterine manipulator eliminates tumor spillage, cervical contamination, and iatrogenic perforation. The advantages of this procedure are particularly useful in EC because uterine manipulation affects oncologic outcomes [ 10 , 11 ]. MFLH has been reported to have an equivalent 5-year disease-free survival rate compared to open surgery [ 11 ]. Comparative studies of EC surgical treatment with a focus on TU-LESS via a retroperitoneal approach for lymphadenectomy with MFLH and MLS with MFLH via a transperitoneal approach, particularly in Chinese patients, are limited. The perioperative safety and short-term oncologic outcomes of TU-LESS combined with MFLH have not been widely studied. Accordingly, the current study aimed to compare the perioperative outcomes and short-term oncologic results between TU-LESS-MFLH and MLS-MFLH for EC staging surgery.