Bibliography on Assisted Reproductive Technology and Gynecological Surgery

This platform serves as a structured resource for clinicians and researchers specializing in assisted reproductive technology (ART) and gynecologic surgery. It has been developed in response to the increasing complexity and rapid evolution of these intersecting fields. The result of collaborative work by gynecologic surgeons highly engaged in both disciplines, each review offers a clear and accessible synthesis of recent studies.

As an innovative alternative to classic abstracts and the often time-consuming reading of full-text scientific papers, this hybrid tool —bridging the gap between conventional abstracts and full-text article reviews— enables rapid identification of high-impact publications while guiding users toward those that warrant deeper exploration.

In addition to bibliographic content, the site offers a range of complementary educational tools, including: Frequently Asked Questions, Podcasts, Structured course outlines derived from the source articles, PowerPoint slide decks for educational use.

Regular updates will reflect major developments in the covered areas, ensuring the content remains relevant and practice-oriented.

Lymph Node Dissection in managing gynecologic cancers

Dr François Dupont

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Dr Anne durand

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Overview

Lymph node dissection (LND) plays a crucial role in the management of gynecologic cancers, particularly for staging purposes, as recommended by the International Federation of Gynecology and Obstetrics (FIGO). For locally advanced cervical cancer (LACC), defined by FIGO as stages IIB to IVA, lymph node metastasis is highly significant for selecting treatment options and predicting patient prognosis.

Traditionally, lymphadenectomy was the primary method for assessing nodal involvement. Current National Comprehensive Cancer Network (NCCN) guidelines recommend simultaneous radiotherapy, primarily pelvic field irradiation, for LACC, with expanded field irradiation for para-abdominal aortic lymph node metastasis. However, the role of LND before initial treatment for LACC, especially concerning enlarged lymph nodes, remains a subject of ongoing debate and controversy.

Despite the debate, a meta-analysis specifically investigating pre-treatment LND for LACC found no significant difference in overall survival (OS) between patients who underwent lymph node dissection and those who received concurrent radiotherapy (Hazard Ratio = 1.11, 95% CI = 0.91–1.36, P = 0.30). Similarly, studies show comparable 5-year recurrence-free survival rates for patients with resected microscopic or macroscopic lymph node metastases compared to those with unresectable nodes. Pre-treatment LND does not appear to increase postoperative complications or cause delays in subsequent radiotherapy.

Even without a clear survival benefit from the dissection itself, LND before initial treatment offers several advantages:

  • Pathological Evaluation and Surgical Staging: It allows for the pathological evaluation of lymph node tissue, which validates imaging findings and improves diagnostic accuracy. Surgical removal of lymph nodes can provide an approximately 20-40% improvement in treatment planning compared to relying solely on PET-CT findings.
  • Radiation Field Definition: LND aids in precisely mapping the radiotherapy area. This is particularly important for larger lymph nodes (e.g., >10 mm or >2 cm), as radiotherapy alone may not be sufficient to eradicate them, and their removal can enhance local control.
  • Avoidance of Overtreatment: By accurately identifying lymph node involvement, LND can prevent unnecessary treatment complications for patients without lymph node metastasis that might otherwise be treated based on false-positive imaging.

Minimally invasive surgery (MIS), including laparoscopic and robotic approaches, has become increasingly common.

  • Conventional Laparoscopic Surgery (CLS) vs. Robot-Assisted Surgery (RAS): For pelvic LND, CLS tends to have a shorter operative time and lower estimated blood loss compared to RAS. However, RAS often results in a greater number of resected pelvic lymph nodes (45 in RAS vs. 38 in CLS), especially in cervical cancer cases (48 in RAS vs. 38 in CLS). This increased yield in RAS may be attributed to its enhanced visualization and greater precision. The rates of major complications and postoperative lymphatic complications (lymphoceles, lymphedema) are comparable between CLS and RAS.
  • vNOTES (Vaginal Natural Orifice Transluminal Endoscopic Surgery): This minimally invasive technique, using transvaginal access, is being explored for sentinel lymph node dissection (SLND) in endometrial cancer staging, with potential benefits like no visible scars, easier ventilation for obese patients (due to no Trendelenburg position), and a lymphatic exploration trajectory that may reduce the risk of missing sentinel nodes. While primarily for SLND, its development highlights the ongoing efforts to minimize surgical invasiveness.

The lymph node ratio (LNR), calculated as the ratio of positive lymph nodes to the total number of resected lymph nodes, is considered a more accurate representation of metastasis status. In gynecological cancers, a higher LNR is consistently associated with a poorer prognosis, including worse overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS). For cervical cancer specifically, higher LNR is linked to a poorer prognosis (HR = 2.53). This underscores LNR’s significance as a prognostic factor, and it is suggested for inclusion in future gynecological cancer staging systems.

In conclusion, while lymph node dissection before initial treatment for locally advanced cervical cancer may not directly improve overall survival, it is valuable for accurate staging, guiding radiation therapy, and avoiding overtreatment. The procedure does carry risks of complications, though severe complications are less common, and newer minimally invasive techniques aim to improve safety and patient outcomes. Further prospective studies are needed to refine and validate these approaches and to determine optimal LND strategies and the clinical utility of LNR thresholds.

FAQ

LND is recommended for accurate surgical staging in cervical, endometrial, and ovarian cancers. Specifically, pelvic LND is recommended for early-stage cervical cancer, and LND is required for accurate staging in endometrial cancer, though sentinel lymph node (SLN) mapping is preferred. For ovarian cancer, systematic pelvic and para-aortic LND of non-enlarged nodes may not enhance overall survival, but removal of bulky nodes proves beneficial in improving progression-free survival.

LACC is defined by FIGO as stage IIB to IVA. Lymph node metastasis is highly significant for selecting treatment options and predicting patient prognosis in LACC. Patients with LACC have a higher probability of lymph node metastasis, paracervical involvement, and lymphovascular infiltration, which are high-risk factors for recurrence, and their 5-year overall survival (OS) rate is significantly lower.

A meta-analysis found no significant difference in overall survival (OS) between LACC patients who underwent pre-treatment LND and those who received concurrent radiotherapy (Hazard Ratio = 1.11, 95% CI = 0.91–1.36, P = 0.30). Similarly, 5-year recurrence-free survival rates were comparable for patients with resected microscopic or macroscopic lymph node metastases.

LND before initial treatment allows for the pathological evaluation of lymph node tissue, which validates imaging findings and improves diagnostic accuracy. Surgical removal of lymph nodes can provide an approximately 20-40% improvement in treatment planning compared to relying solely on PET-CT findings. It also helps precisely map the radiotherapy area.

In cases where imaging or surgical staging detects enlarged lymph nodes, radiotherapy alone may not be sufficient to eradicate them, and their removal can enhance local control. Removing larger lymph nodes (e.g., >10 mm or >2 cm) may also aid in defining the radiation field and decreasing radiotherapy-related complications.

A retrospective study reported an overall complication rate of 42.4%. The rates were 26.1% for intra-operative, 11.0% for acute post-operative, and 14.0% for long-term complications. The major complication rate was 13.5%.

Intra-operative complications can include injury to adjacent organs such as vessels (3.3%), bowel (3.3%), bladder (1.3%), and ureter (0.8%). Significant blood loss exceeding 1,000 mL occurred in 20.3% of cases in one study.

Acute post-operative complications include surgical site infection (4.0%), bowel ileus (2.0%), and cystitis (1.5%). Venous thromboembolism (VTE) occurred in 0.8% of cases in the acute period.

Long-term complications, typically occurring after 30 days, include symptomatic lymphocele (6.0%) and lymphedema (2.0%). Symptomatic lymphoceles often resolve spontaneously, while lymphedema cases typically present with mild symptoms and are managed with self-bandaging and physical therapy.

Factors associated with higher overall and intra-operative complication rates include laparotomy, positive lymph nodes, and operative time exceeding 240 minutes. Laparotomy is a significant predictor for both overall and intra-operative complications. Patients with at least one complication also had a significantly lower 5-year survival rate, particularly among those without metastatic lymph nodes.

For pelvic LND, CLS generally has a shorter operative time (46 min vs. 52 min) and lower estimated blood loss (89 mL vs. 110 mL) compared to RAS. However, RAS often results in a greater number of resected pelvic lymph nodes (45 vs. 38), especially in cervical cancer cases (48 vs. 38). The rates of major complications and postoperative lymphatic complications (lymphoceles, lymphedema) are comparable between CLS and RAS.

SLND is a less extensive procedure that provides essential staging information while reducing patient morbidity compared to systematic lymphadenectomy. It is now standard practice in the staging of endometrial cancer. SLND has replaced systematic lymphadenectomy, which is associated with higher morbidity.

CVS criteria are anatomical structures that must be identified before completing SLND to standardize surgical quality, improve the precision of SLN identification, and lead to better patient outcomes. These include the ureter, obliterated umbilical artery, external iliac vessels, and internal iliac artery. Proper identification minimizes the risk of intra-operative complications from inadvertent injuries and ensures comprehensive visualization of lymphatic pathways.

While the lateral pararectal and paravesical spaces are identified with high rates (62% and 94% respectively) and strong inter-rater agreement, the internal iliac artery has a lower assessment rate (32%) and moderate inter-rater agreement. This suggests greater difficulty in consistently identifying the internal iliac artery due to its deeper anatomical location and increased surgical complexity, which could raise concerns about missing sentinel lymph nodes in the internal iliac and pre-sacral area.

vNOTES (Vaginal Natural Orifice Transluminal Endoscopic Surgery) is a minimally invasive technique using transvaginal surgical access, eliminating the need for abdominal incisions. For retroperitoneal SLND in endometrial cancer, vNOTES offers advantages such as no visible scars, operating without Trendelenburg position (beneficial for obese patients by offering easier ventilation), and following the natural lymph node trajectory from caudally to cranially, potentially reducing the risk of missing the sentinel node.

In a prospective multicenter case series, there were 10 perioperative or short-term postoperative complications among 64 patients. These included bladder injury in three cases (5%), one surgical reintervention for bleeding, one case of adductor paresis, one obturator vein laceration, and one femoral deep vein thrombosis. There were no conversions to laparotomy, and one conversion to laparoscopy.

The LNR is calculated as the ratio of positive lymph nodes to the total number of resected lymph nodes. It is considered a more accurate representation of metastasis status compared to just the number of positive nodes, as it accounts for potential confounding effects of surgical technique and pathological examination accuracy.

A higher LNR is consistently associated with a poorer prognosis across various gynecological cancers, including cervical cancer (HR=2.53), ovarian cancer (HR=2.05), endometrial cancer (HR=2.16), and vulvar cancer (HR=8.13). This association holds true for worse overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS).

In general, LND was not an independent prognostic factor for survival in early-stage EOC after adjusting for other variables. However, in patients with serous histology, lymphadenectomy was associated with improved 5-year disease-free survival (86.5% vs. 74.4%). This suggests that LND might offer a survival benefit from stage-adapted adjuvant chemotherapy, rather than from direct surgical excision of lymph nodes, especially in certain histological subtypes.

Bibliography

Saemathong, T., & Chaowawanit, W. (2024).
A Retrospective Study of Complications Following Pelvic and Para-Aortic Lymphadenectomy in Gynecologic Oncology. World J Oncol, 15(3), 423-431. doi: https://doi.org/10.14740/wjon1824

Pavone, M., Baby, B., Carlese, E., Innocenzi, C., Baroni, A., Arboit, L., Murali, A., Rosati, A., Iacobelli, V., Fagotti, A., Fanfani, F., Akladios, C., Querleu, D., Bizzarri, N., Lecointre, L., Mascagni, P., Padoy, N., & Scambia, G. (2025).
Critical view of safety assessment in sentinel node dissection for endometrial and cervical cancer: artificial intelligence to enhance surgical safety and lymph node detection (LYSE study). International Journal of Gynecological Cancer. Available online 27 March 2025. https://doi.org/10.1016/j.ijgc.2025.101789

Zhang, H., Ao, M., Wu, Y., Mao, W., Luo, H., Wang, K., & Li, B. (2024).
Lymph node dissection before initial treatment for locally advanced cervical cancer: A systematic review and meta-analysis. Biomolecular Biomedicine. DOI: 10.17305/bb.2024.10591

Chen, M., Wang, Y., Chen, Y., Han, L., & Zheng, A. (2024).
The prognostic values of lymph node ratio for gynecological cancer: a systematic review and meta-analysis. Front. Oncol., 14, 1475348. doi: 10.3389/fonc.2024.1475348

Yang, E. J., Lee, A. J., Hwang, W. Y., Chang, S. J., Kim, H. S., Kim, N. K., Kim, Y., Kong, T. W., Lee, E. J., Park, S. J., Son, J. H., Suh, D. H., Son, D. H., & Shim, S. H. (2024).
Lymphadenectomy in clinically early epithelial ovarian cancer and survival analysis (LILAC): a Gynecologic Oncology Research Investigators Collaboration (GORILLA-3002) retrospective study. J Gynecol Oncol, 35, e75. https://doi.org/10.3802/jgo.2024.35.e75

Aiko, K., Kanno, K., Yanai, S., Sawada, M., Sakate, S., & Andou, M. (2024).
Robot-Assisted versus Laparoscopic Surgery for Pelvic Lymph Node Dissection in Patients with Gynecologic Malignancies. Gynecol Minim Invasive Ther, 13, 37-42. DOI: 10.4103/gmit.gmit_9_23

Baekelandt, J., Jespers, A., Huber, D., Badiglian-Filho, L., Stuart, A., Chuang, L., Ali, O., & Burnett, A. (2024).
vNOTES retroperitoneal sentinel lymph node dissection for endometrial cancer staging: First multicenter, prospective case series. Acta Obstet Gynecol Scand, 103, 1311-1317. doi:10.1111/aogs.14843

Lymphadenectomy is a crucial component of staging protocols for gynecologic cancers, as recommended by the International Federation of Gynecology and Obstetrics (FIGO). While its benefits in cancer management vary, complications can occur across different timeframes: intra-operative, acute post-operative, and long-term. Previous systematic reviews have highlighted significant risks associated with lymphadenectomy, including systemic morbidity (e.g., chest infection, thrombo-embolic events, cardiac events, cerebrovascular accidents) and specific complications like lymphocele and lymphedema. The study aims to detail these complications within a specific patient cohort.

Methodology and Patient Demographics The study involved 399 patients diagnosed with cervical, endometrial, or ovarian cancers who underwent pelvic and para-aortic lymphadenectomy at the Faculty of Medicine, Vajira Hospital, Navamindradhiraj University, in Thailand, between January 2015 and March 2020. Patients were followed for at least 3 months post-surgery. The mean age of the cohort was 53.7 ± 12.4 years, with a mean body mass index (BMI) of 25.8 ± 5.8 kg/m². Nearly 60% of patients had at least one underlying disease, such as hypertension (35.8%) or diabetes mellitus (21.3%). Endometrial cancer was the most common diagnosis (43.6%), followed by ovarian (35.1%), cervical (20.3%), and synchronous cancers (1.0%).

Surgical procedures were performed by experienced gynecologic oncology surgeons or fellowship trainees under supervision. The predominant surgical approach was laparotomy, utilized in 88.7% of all cases, with only 11.3% undergoing laparoscopy. Most patients (72.9%) underwent both pelvic and para-aortic lymphadenectomy. The mean operative time was 273.9 ± 88.2 minutes, and the mean total blood loss was 689.7 ± 757.3 mL. On average, 20.4 ± 10.3 lymph nodes were resected. Lymph node metastasis (positive lymph nodes) was found in 20.3% of patients.

Complications were rigorously categorized:

  • Intra-operative complications were defined as those occurring during surgery, including injury to adjacent organs, blood vessels, or nerves, and significant blood loss exceeding 1,000 mL.
  • Acute post-operative complications occurred within 29 days post-surgery, encompassing issues like cellulitis, cystitis, wound infection, sepsis, bleeding requiring relaparotomy, and venous thromboembolism (VTE).
  • Long-term complications were observed after 30 days, including lymphocele, lymphedema, bowel obstruction, and incisional hernia.
  • Major complications were classified as Grade 3-5 according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

Key Findings on Complication Rates and Predictors The study reported an overall complication rate of 42.4%. Breaking this down by timing:

  • Intra-operative complications occurred in 26.1% of patients. The most frequent intra-operative complication was blood loss exceeding 1,000 mL, affecting 20.3% of patients. Other injuries included vessel injury (3.3%), bowel injury (3.3%), bladder injury (1.3%), and ureteric injury (0.8%).
  • Acute post-operative complications were observed in 11.0% of patients. Surgical site infection (4.0%) and bowel ileus (2.0%) were among the notable acute complications. Lymphocele was reported in 1.0% of cases in this acute phase.
  • Long-term complications occurred in 14.0% of patients. The most common long-term complications were symptomatic lymphocele (6.0%) and lymphedema (2.0%). Symptomatic lymphoceles appeared between 16 and 1,301 days post-surgery, with most cases resolving spontaneously. Lymphedema, characterized by mild symptoms, typically appeared between 51 and 204 days post-surgery and was managed with self-bandaging and physical therapy.

The rate of major complications across the entire cohort was 13.5%. When stratified by cancer type, ovarian cancer patients exhibited the highest major complication rate (21.9%), compared to cervical cancer (8.4%) and endometrial cancer (8.8%).

Logistic regression analysis identified significant predictors for overall complications:

  • Laparotomy (Odds Ratio [OR]: 5.62, 95% CI: 2.27-13.86, P < 0.001).
  • Positive lymph nodes (OR: 2.10, 95% CI: 1.26-3.51, P = 0.005).
  • Operative time > 240 minutes (OR: 1.90, 95% CI: 1.21-2.99, P = 0.006). These three factors were also independent predictors for intra-operative complications, along with age > 60 years. No significant factors were found to predict acute post-operative or long-term complications. Patients with positive lymph nodes generally had higher overall and intra-operative complication rates compared to those with negative lymph nodes.

Impact on Survival The study found that patients who experienced at least one complication had a significantly lower 5-year survival rate (92.31%) compared to those without complications (97.39%). However, in a subgroup analysis focusing on patients with or without lymph node metastasis, no significant difference in survival between patients with or without complications was observed. Interestingly, among patients without metastatic lymph nodes, those who experienced complications had a significantly lower survival rate than those without complications.

Discussion and Clinical Implications The observed overall complication rate (42.4%) in this study is notably higher than some rates reported in other gynecologic oncology surgical cohorts, such as 33.8% for endometrial cancer or 13.3-29.9% for ovarian cancer in previous studies. The major complication rate of 13.5% was also higher than the 3.6-3.7% reported in some prior research. The authors attribute this higher rate primarily to the predominant use of laparotomy (88.7%) in their cohort, as laparotomy is a significant predictor of complications. The fact that the study was conducted at a university hospital, where fellowship trainees perform surgeries under supervision, and that the patient population often involved advanced-stage disease referred from other hospitals (leading to longer operative times), might also contribute to the higher rates.

Despite the relatively high overall complication rate, the study emphasizes that the rate of severe complications was low. This suggests that lymphadenectomy in gynecologic cancer surgery can generally be performed safely. The prevalence of specific long-term complications, such as symptomatic lymphocele (6.0%) and lymphedema (2.0%), was found to be at the lower end of previously reported ranges (4.0-7.1% for symptomatic lymphocele and 11.4-36.9% for lymphedema). The authors suggest that the low reported incidence of lymphedema might be due to mild symptoms not consistently being recorded in the retrospective medical records.

The findings underscore the importance of surgical approach, lymph node status (indicating disease advancement), and operative time as key factors influencing complication rates. Given the limitations of this retrospective study, particularly the heterogeneous nature of the combined cancer types, the authors recommend future prospective, multi-center studies to further refine risk stratification and optimize patient care strategies in gynecologic cancer surgeries.

In conclusion, this study provides valuable insights into the complications associated with pelvic and para-aortic lymphadenectomy in gynecologic oncology patients. While a significant proportion of patients experience some form of complication, the rates of severe complications remain low, reinforcing the safety of the procedure, especially when performed by experienced surgeons.

The overarching goal of defining and assessing these CVS is to standardize the evaluation of surgical quality, enhance the precision of SLN identification, and ultimately improve patient outcomes. This research is particularly pertinent as SLN dissection has largely replaced systematic lymphadenectomy due to its association with higher morbidity. However, even with SLN techniques, concerns remain regarding peri-operative complications, mapping failures (occurring in 20-25% of cases), and instances of “empty node packets” where no lymph node tissue is found. Standardization of procedures and objective assessment tools are thus crucial.

Methodology and Study Population The study was conducted from April to September 2024, collecting surgical videos from patients with cervical and endometrial carcinoma undergoing minimally invasive SLN dissection (laparoscopic/robotic). A total of 80 patients were initially enrolled, with 71 cases (88.8%) having videos suitable for annotation. The majority of these patients (90.1%) underwent SLN dissection for endometrial cancer, while 9.9% were for cervical cancer. The median age of the cohort was 52 years, and the median body mass index (BMI) was 28.8 kg/m². Most surgeries (90.1%) were performed via a laparoscopic approach, with 9.9% using robotic surgery. The median operative time was 134 minutes, and estimated blood loss was 50 mL.

The study proposed three specific Critical Views of Safety (CVS) criteria, based on anatomical structures deemed mandatory for identification prior to SLN dissection, as established by expert consensus:

  1. Lateral Pararectal Space (LPRS): Defined by identifying the space below the uterine artery, bounded laterally by the obliterated umbilical artery and medially by the ureter.
  2. Lateral Paravesical Space (LPVS): Identified as the space between the external iliac vessels and the obliterated umbilical artery.
  3. Internal Iliac Artery (IIA): Defined by the identification of at least one margin of the vessel, or a white tubular structure medial to the ureter and below the obliterated umbilical artery, or the emergence of the obliterated umbilical artery itself.

To assess the applicability (content validity) and inter-rater agreement (reliability) of these criteria, three independent surgeons, blinded to each other’s assessments, evaluated the videos. The surgical phase focused on left SLN dissection, from the opening of the left round ligament to the ex vivo testing of lymph node fluorescence in the pelvis. An online cloud-based collaborative video annotation platform, MOSaiC, was used for this purpose. A CVS criterion was considered “achieved” if at least two of the three annotators agreed on its identification. Statistical analysis included descriptive statistics and Fleiss’ Kappa for inter-rater reliability.

Key Findings The study successfully annotated 71 surgical videos. The assessment rates for the proposed CVS criteria were:

  • Lateral Paravesical Space (LPVS): Identified in 94% of videos.
  • Lateral Pararectal Space (LPRS): Identified in 62% of videos.
  • Internal Iliac Artery (IIA): Identified in only 32% of videos.

The inter-rater reliability among annotators was strong for both the lateral pararectal and paravesical spaces, with a Fleiss’ Kappa of 0.90 for both, indicating high agreement. However, reliability for the internal iliac artery was moderate, with a Fleiss’ Kappa of 0.73.

Notably, no intra-operative or post-operative complications were reported in this cohort. The median number of sentinel lymph nodes removed from the left side was 1 (IQR 1-2). Left metastatic sentinel lymph nodes were found in 9.9% of patients (7 out of 71), including macro-metastases (4.2%), micro-metastases (2.8%), and isolated tumor cells (2.8%). The most common location for detected SLNs was the external iliac (67.6%), followed by obturator (19.7%).

Discussion and Clinical Implications The study’s findings affirm the feasibility of video-based CVS assessment in SLN dissection for endometrial and cervical cancer, particularly for the lateral pararectal and paravesical spaces, given their high achievement rates and strong inter-rater agreement. This reinforces the clinical applicability of identifying key anatomical landmarks, such as the external iliac vessels, obliterated umbilical artery, and ureters, before SLN dissection. Proper identification of these structures is crucial not only for preventing inadvertent injuries but also for ensuring comprehensive visualization of lymphatic pathways, which enhances the accuracy of SLN detection.

However, the significantly lower achievement rate (32%) for identifying the internal iliac artery is a key concern. This suggests greater surgical difficulty due to its deeper anatomical location. This inconsistency in detection raises concerns about potentially missing sentinel lymph nodes in the internal iliac and pre-sacral areas, which could compromise the success of the SLN procedure.

The study highlights that SLN dissection has replaced systematic lymphadenectomy, primarily due to the latter’s higher morbidity rates, which include surgical-related systemic morbidity, lymphocele, and lymphedema. While other sources indicate overall complication rates for lymphadenectomy can be as high as 42.4%, the fact that no complications were reported in this specific SLN dissection cohort further supports the safety advantages of the SLN approach. The study suggests that adherence to standardized CVS, validated through video assessment, could help reduce the documented rates of SLN mapping failures (20-25%) and empty node packets (up to 20%) that occur, especially during a surgeon’s learning curve.

This research is presented as a foundational step towards integrating advanced technologies into surgical safety. Similar to its successful application in laparoscopic cholecystectomy for preventing bile duct injuries, video-based assessment of CVS lays the groundwork for developing artificial intelligence (AI) algorithms. Such AI tools could automatically assess and document the achievement of these safety criteria in surgical videos, offering real-time assistance and standardizing safety checklists across institutions. This objective analysis of surgical steps could optimize adherence to guidelines and identify new strategies to reduce operative risks.

Strengths and Limitations A notable strength of the study is its approach to defining CVS based on spatial anatomical coordinates, which reduces ambiguity and improves inter-rater reliability compared to focusing on single anatomical structures. The rigorous annotation protocol further enhanced the reliability of the visual assessments. The multi-center, prospective nature of the study, involving four different surgeons, contributes to the generalizability of its findings on feasibility.

However, the study acknowledges several limitations. The inherent difficulty in visualizing the deep retroperitoneal position of the internal iliac artery contributed to its lower assessment rate. The focus on only the left side of the pelvis, while justified for feasibility assessment, means that consistency across both sides and intra-surgeon consistency need further investigation. Additionally, being an early cohort, the findings serve as an initial indication of feasibility rather than a definitive comparison with existing large-scale studies.

Conclusion In conclusion, the LYSE study successfully demonstrates the feasibility of video-based assessment of Critical Views of Safety criteria in sentinel lymph node dissection for endometrial and cervical cancer, achieving high identification rates and inter-rater agreement for the pararectal and paravesical spaces. The lower assessment rate of the internal iliac artery highlights a critical area for surgical improvement to ensure comprehensive SLN detection. This pioneering study establishes a crucial foundation for the future development of AI-driven algorithms to automatically assess and document surgical safety and enhance the accuracy of minimally invasive SLN dissection. By standardizing surgical procedures and ensuring adherence to guidelines, such tools hold immense promise for improving patient outcomes in gynecologic oncology.

Cervical cancer remains a significant health challenge, with its incidence and mortality rates being a concern, particularly in advanced stages where lymph node metastasis (LNM) is a common predictor of poor prognosis. Accurate assessment of lymph node involvement is essential for effective staging and guiding subsequent treatment decisions, including adjuvant radiation and chemotherapy.

Historically, systematic lymphadenectomy has been a standard part of staging for gynecologic cancers, as recommended by the International Federation of Gynecology and Obstetrics (FIGO). However, this extensive procedure is well-known to be associated with various complications. These include systemic morbidity (such as chest infections, thrombo-embolic events, and cardiac events) and specific complications like lymphedema and lymphocyst formation. One study revealed an overall complication rate of 42.4% for lymphadenectomy, with intra-operative complications at 26.1%, acute post-operative at 11.0%, and long-term at 14.0%. Factors like laparotomy, positive lymph nodes, and operative time exceeding 240 minutes were identified as significant predictors of overall complications. Symptomatic lymphocele and lymphedema, specifically linked to lymphadenectomy, were reported in 6.0% and 2.0% of patients, respectively. Despite these risks, the authors of that study concluded that lymphadenectomy can be performed safely.

Given the morbidity associated with systematic LND, sentinel lymph node (SLN) biopsy has emerged as a less invasive and highly accurate alternative, proving more sensitive in detecting nodal disease, including micrometastases and isolated tumor cells, compared to traditional full lymphadenectomy. However, even SLN mapping techniques carry risks such as peri-operative complications, mapping failures (occurring in 20-25% of cases, and up to 20% for surgeons early in their learning curve), and “empty node packets” where no lymph node tissue is found (up to 8% in obese patients). Furthermore, while modern imaging like PET/CT is used for evaluating LNM, it still has a false-negative rate of 6%–15% for para-aortic lymph nodes. For LACC patients, where radiotherapy is the primary treatment, there is concern that standard radiation doses may not be sufficient to eradicate enlarged lymph nodes, raising questions about whether surgical removal of these nodes could improve outcomes. This meta-analysis aimed to systematically evaluate the impact of pre-treatment LND on oncological outcomes and postoperative complications in LACC to provide clarity on this controversy.

Methodology The study utilized a systematic literature review and meta-analysis approach, adhering to the PRISMA guidelines and registered with PROSPERO. The search spanned major scientific databases (PubMed, Embase, Science Direct, Cochrane Database of Systematic Reviews) up to December 2023. Inclusion criteria focused on studies of LACC patients (FIGO 2009 stage IB2, IIA2–IVA) where LND was performed as initial treatment, compared to control groups receiving radiotherapy or chemotherapy only. Detailed patient, treatment, and outcome data were extracted, and the quality of included cohort studies was rigorously assessed using the Newcastle–Ottawa Scale. Statistical analysis involved fixed-effects models to synthesize hazard ratios (HR) for survival outcomes, with heterogeneity and publication bias (via Egger’s test) also evaluated.

Key Findings From an initial pool of 1,025 articles, the systematic review ultimately included four studies, encompassing a total of 838 women with LACC. These studies, published between 2012 and 2022, were conducted in various countries, including Spain, The Netherlands, Germany, and Taiwan. All selected studies demonstrated a low risk of bias according to the Newcastle–Ottawa scale.

The central finding of the meta-analysis indicated that pre-treatment lymph node dissection did not significantly affect overall survival (OS) in patients with locally advanced cervical cancer (HR = 1.11, 95% CI = 0.91–1.36, P = 0.30) when compared to patients receiving concurrent radiotherapy. This suggests no direct survival benefit from performing LND as an initial step for LACC.

Crucially, the study also found that pre-treatment LND did not increase the incidence of postoperative complications or cause delays in subsequent radiotherapy. This is an important finding given the known complications of lymphadenectomy discussed in other sources, particularly those associated with open surgery, which can have complication rates as high as 34% compared to 1.6%–7% for laparoscopic approaches. The meta-analysis detected no significant publication bias.

Discussion and Clinical Implications Despite the absence of a direct OS benefit, the authors emphasize the critical roles and advantages of pre-treatment LND in LACC management.

Enhanced Staging and Diagnostic Precision: Performing LND before primary treatment facilitates a precise pathological evaluation of lymph nodes, which can improve diagnostic accuracy by approximately 20%–40% compared to imaging modalities like PET-CT. This provides invaluable, concrete information for accurate surgical staging, leading to more tailored and precise treatment planning for individual patients.

Optimized Radiotherapy Planning: For patients with LNM, particularly those with enlarged positive lymph nodes (e.g., >10 mm or >2 cm), surgical removal can be therapeutically beneficial. Such large nodes are challenging to eradicate with conventional radiotherapy doses and may not be adequately covered by the radiation field. LND allows for better local control and enables surgeons to accurately delineate the radiation field, thereby minimizing potential radiation-related complications and preventing overtreatment in patients without nodal involvement.

Surgical Approach Considerations: The choice of surgical approach for LND also influences outcomes. While the study indicates no increase in overall complications from pre-treatment LND, other sources highlight the benefits of minimally invasive surgery (MIS) techniques. Robotic-assisted surgery (RAS) for pelvic lymph node dissection (PLND) may result in a greater number of resected lymph nodes, especially for cervical cancer, compared to conventional laparoscopic surgery (CLS), although RAS might involve slightly longer operative times and greater blood loss. Novel approaches like vaginal natural orifice transluminal endoscopic surgery (vNOTES) offer additional advantages such as no abdominal incisions, reduced postoperative pain, shorter hospital stays, and avoiding the Trendelenburg position which aids in ventilation for obese patients. However, vNOTES is a relatively new technique with a learning curve, and an initial cohort experienced a bladder injury rate of 5%, higher than rates typically reported for laparoscopic hysterectomies.

Prognostic Value of Lymph Node Burden: Beyond the presence of positive nodes, the lymph node ratio (LNR)—the ratio of positive to total resected lymph nodes—is recognized as a powerful prognostic tool. A higher LNR consistently correlates with worse OS, PFS, and DFS across various gynecologic cancers, including cervical cancer. This emphasizes that even if pre-treatment LND doesn’t directly improve OS, the detailed information it provides about the extent of nodal disease is profoundly significant for prognosis and for guiding adjuvant therapy choices.

Limitations and Future Directions: The authors acknowledge that the retrospective nature of most included studies and the limited sample size are significant limitations, potentially affecting the generalizability and robustness of the findings. Variability in patient characteristics and surgical techniques across studies also contributes to heterogeneity. Nevertheless, the study highlights the initiation of new prospective randomized controlled trials (e.g., Casper, NCT04555226) that are expected to provide more definitive evidence.

Conclusion In conclusion, this meta-analysis suggests that while pre-treatment lymph node dissection for locally advanced cervical cancer may not offer a clear, direct survival advantage, its diagnostic and guiding roles are invaluable. It enables accurate pathological staging and precise radiotherapy planning, potentially preventing both undertreatment of macroscopic disease and overtreatment in patients without nodal involvement, thereby reducing treatment-related complications. Furthermore, the study confirms that this LND can be performed without increasing overall postoperative complications or delaying subsequent treatment. The authors recommend that gynecologic oncologists consider tailored treatment strategies, emphasizing accurate pre-treatment lymphatic assessment to identify patients who would most benefit from LND. Further randomized controlled studies are necessary to conclusively validate the full impact of pelvic lymph node dissection in this specific patient population.

Lymph node metastasis is a frequent occurrence in gynecological cancers and significantly impacts patient prognosis. Traditionally, the number of positive nodes identified during pelvic lymphadenectomy has been used to assess prognosis; however, this count can be influenced by surgical technique and the accuracy of pathological examination. To address these potential confounding effects, the LNR has been proposed as a more precise measure of pelvic lymph node metastasis status. The study sought to consolidate existing research to determine if a higher LNR is consistently associated with worse overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS) across cervical cancer (CC), ovarian cancer (OC), endometrial cancer (EC), and vulvar cancer (VC).

Methodology The authors performed a systematic literature search across major scientific databases, including PubMed, Web of Science, Embase, and the Central Cochrane Library, for studies published before April 18, 2024. The search focused on articles investigating the relationship between LNR and OS, PFS, or DFS in patients with pathologically confirmed CC, OC, EC, and VC. Studies were included if they reported a hazard ratio (HR) with a 95% confidence interval (CI) for these survival outcomes and were published as full articles in English. Exclusion criteria included lack of extractable data, absence of survival data or 95% CI, and publications such as editorials, reviews, or comments. When patient data overlapped across multiple studies, the most recent publication was selected.

Data extraction involved recording the first author, publication date, sample size, cancer type, country, average age, follow-up duration, LNR cutoff value, and patient outcomes (OS, PFS, DFS). OS was defined as the period from initial therapy to all-cause mortality, PFS as the time from initial therapy to disease progression, and DFS as the time from surgery to the last follow-up without evidence of recurrence or distant metastasis. The quality of the included non-randomized studies was independently assessed by two reviewers using the Newcastle–Ottawa Scale (NOS), with a score of ≥6 indicating high-quality literature for inclusion. Statistical analysis utilized STATA 15.0 software, employing random- or fixed-effects models based on heterogeneity (measured by I² statistics). Sensitivity analysis and publication bias (Begg’s funnel plots and Egger’s test) were also conducted.

Key Findings The meta-analysis ultimately included 34 studies involving 23,202 cases. All included studies were retrospective and received a NOS score of seven or more stars, indicating low risk of bias. The included patients were from various countries, with a mean age of 50.8 years.

The primary outcomes revealed a clear association between higher LNR and poorer prognosis across all metrics:

  • Overall Survival (OS): A meta-analysis of 32 studies (13 on CC, 9 on OC, 7 on EC, 3 on VC) found that higher LNR was associated with worse OS (HR = 2.42, 95% CI: 2.07–2.83; I² = 77.4%, p < 0.05). High heterogeneity was noted for OS (I² = 77.4%, p < 0.05).
  • Progression-Free Survival (PFS): Ten studies (7 on EC, 2 on CC, 1 on OC) showed that higher LNR levels were associated with worse PFS (HR = 1.97, 95% CI: 1.66–2.32; I² < 50%, p > 0.05), with low heterogeneity.
  • Disease-Free Survival (DFS): Eight studies (6 on CC, 1 on OC, 1 on VC) indicated that higher LNR levels were associated with worse DFS (HR = 3.18, 95% CI: 2.12–4.76; I² = 64.3%, p < 0.05), with high heterogeneity.

Subgroup analysis based on cancer type further elucidated the relationship between LNR and OS, all showing higher LNR associated with worse outcomes:

  • Cervical Cancer (CC): HR = 2.53, 95% CI: 1.94–3.31; I² = 72.6%.
  • Ovarian Cancer (OC): HR = 2.05, 95% CI: 1.66–2.54; I² = 76.7%.
  • Endometrial Cancer (EC): HR = 2.16, 95% CI: 1.48–3.16; I² = 53.6%.
  • Vulvar Cancer (VC): HR = 8.13, 95% CI: 3.41–19.43; I² = 57.2%.

Meta-regression analysis identified sample size as the main factor contributing to heterogeneity in OS (p = 0.014). Sensitivity analysis demonstrated the robustness of the HRs, with results remaining relatively stable even when individual studies were excluded. Publication bias was suggested by visual inspection of Begg’s funnel plot for OS, although Egger’s test had a p-value of 0.255.

Discussion and Clinical Implications The study’s findings consistently demonstrated that a higher LNR is significantly associated with poorer prognosis across gynecological cancers. This reinforces LNR as a critical prognostic factor, potentially more accurate than simply counting positive lymph nodes because it accounts for the total number of resected nodes, thereby reducing confounding effects from surgical technique or pathological examination.

  • Cervical Cancer (CC): The pooled HR for OS in CC was 2.53. This study’s findings align with previous meta-analyses confirming LNR as an unfavorable prognostic factor for OS and DFS in CC. Although FIGO staging for CC now includes lymph node metastasis by anatomic location, it does not consider other lymph node characteristics, making LNR potentially valuable.
  • Ovarian Cancer (OC): A higher LNR was linked to poorer prognosis (HR = 2.05 for OS). The prognostic value of LNR has been validated across various OC histological subtypes, including high-grade serous, low-grade serous, clear cell, and borderline ovarian tumors. Some research suggests LNR’s prognostic value surpasses that of total or positive lymph node counts. While another source suggests lymphadenectomy itself may not offer a survival benefit in early-stage epithelial ovarian cancer (EOC) after adjusting for prognostic variables, especially if adjuvant chemotherapy is administered, this study highlights LNR as a robust prognostic marker within the context of lymph node assessment, which is crucial for guiding subsequent treatment.
  • Endometrial Cancer (EC): Higher LNR was associated with worse OS (HR = 2.16) and PFS. LNR demonstrated better predictive performance compared to other lymph node staging schemes. However, the prognostic value of LNR might be limited to patients who have undergone a minimum threshold of lymph node removal, which is not yet a universally adopted clinical standard. Systematic lymphadenectomy, while crucial for staging, is associated with complications like surgical-related systemic morbidity, lymphocele, and lymphedema, with overall complication rates for lymphadenectomy potentially reaching 42.4%. Sentinel lymph node dissection, a less invasive alternative, aims to reduce such morbidity. In this context, LNR provides a more refined prognostic assessment that can help tailor adjuvant therapy decisions following lymph node assessment, rather than necessarily increasing the extent of lymphadenectomy.
  • Vulvar Cancer (VC): LNR was identified as a consistent, independent prognostic parameter for both OS (HR = 8.13) and DFS in VC, demonstrating superior predictive value over the number of positive lymph nodes.

Strengths and Limitations The study’s strengths include being the first comprehensive meta-analysis to quantify LNR’s role across multiple gynecological cancers, encompassing a large number of primary studies (34 papers) and patients (23,202 cases), which bolsters statistical robustness. This supports the recommendation for LNR to be included in future gynecological cancer staging systems.

However, limitations stemming from its retrospective nature and reliance on published data may introduce bias. The inconsistency in LNR cutoff values across different studies, and the absence of detailed data on tumor size, pathological stages, and specific surgical methods, limited further subgroup analysis. Despite these limitations, the study provides a valuable consolidation of evidence regarding LNR’s prognostic significance.

Conclusion The Chen et al. meta-analysis conclusively demonstrates that a higher lymph node ratio (LNR) is strongly associated with poorer overall survival, progression-free survival, and disease-free survival in patients with gynecological cancers. This prognostic value is consistent across cervical, ovarian, endometrial, and vulvar cancers. The study advocates for the inclusion of LNR as a prognostic parameter in future gynecological cancer staging systems due to its ability to provide a more accurate and reliable assessment of lymph node metastasis status, moving beyond simple lymph node counts. Future prospective studies are crucial to establish optimal LNR thresholds, define the minimum necessary lymph node removal, and investigate LNR’s effectiveness in guiding adjuvant therapy decisions, ultimately aiming to personalize treatment and enhance patient outcomes while minimizing unnecessary procedures and associated morbidity.

Ovarian cancer remains the most lethal gynecologic cancer, with most patients typically diagnosed at advanced stages. While standard EOC treatment involves surgical resection of all visible tumors and systemic chemotherapy, pelvic and para-aortic lymphadenectomy is performed as part of surgical staging to resect lymph nodes and identify metastases. In clinically early-stage EOC, the incidence of true lymph node metastasis after lymphadenectomy is approximately 14.2%, with rates varying by histologic subtype.

Lymphadenectomy has been suggested to play both a therapeutic role (removing occult tumors from lymph nodes) and a diagnostic role (defining disease stage to influence chemotherapy choice). However, the therapeutic role in early-stage EOC has had inconsistent results in prior retrospective studies. This multicenter retrospective cohort study sought to address this by evaluating lymphadenectomy’s therapeutic impact in clinically early-stage EOC, with disease-free survival (DFS) as the primary outcome and overall survival (OS) and perioperative outcomes as secondary outcomes.

Methods This was a multicenter, retrospective cohort study conducted across four tertiary medical institutions in Korea, reviewing electronic medical records from September 2007 to April 2021. Patients included were those with previously untreated primary EOC, presumed International Federation of Gynecology and Obstetrics (FIGO) stages I/II based on preoperative radiologic examinations (CT or MRI), who underwent staging surgery. Patients with distant metastasis, those who received neoadjuvant chemotherapy, or those with other relevant medical histories were excluded.

Clinicopathologic data, operative time, estimated blood loss (EBL), and perioperative complications were collected. Lymphadenectomy was defined as the removal of all suspected and enlarged lymph nodes, including pelvic and/or para-aortic nodes, and patients undergoing this procedure were grouped as the lymphadenectomy group, irrespective of the number of nodes collected. Statistical analyses included Mann–Whitney U test, χ2 test, Fisher’s exact test, Kaplan-Meier method with log-rank test for survival, and Cox regression models for prognostic significance. Propensity score matching with inverse probability of treatment weighting (IPTW) was used to balance baseline patient characteristics between groups.

Results A total of 586 patients met the inclusion criteria: 453 (77.3%) underwent lymphadenectomy, and 133 (22.7%) did not. The median number of resected lymph nodes in the lymphadenectomy group was 21, with 81.9% of cases (371 out of 453) having 10 or more lymph nodes harvested, indicating appropriate surgical quality.

Before IPTW adjustment, the lymphadenectomy group had significantly higher median preoperative serum CA125 levels and a greater frequency of histologic grade 2/3 tumors, as well as differing histologic type proportions (more clear cell, less mucinous). IPTW successfully balanced these baseline characteristics.

Perioperative Outcomes: The lymphadenectomy group experienced:

  • Significantly longer median operation time (200 minutes vs. 135 minutes, p<0.001).
  • Significantly higher median EBL (400 mL vs. 200 mL, p<0.001).
  • More frequent perioperative adverse events (12.1% vs. 3.0%, p=0.004).
  • Upstaging based on lymph node metastasis occurred in 3.1% (14 out of 453) of patients in the lymphadenectomy group.

Survival Outcomes: Overall, at a median follow-up of 44 months, there was no significant difference in 5-year DFS (88.9% vs. 83.4%, p=0.203) and no significant difference in 5-year OS (97.2% vs. 97.7%, p=0.895) between the lymphadenectomy and non-lymphadenectomy groups. Multivariable analysis confirmed that lymphadenectomy was not significantly associated with either DFS or OS after adjusting for other prognostic factors.

However, subgroup analysis revealed a significant survival benefit for lymphadenectomy in specific patient populations:

  • For patients with serous histology, the lymphadenectomy group showed significantly better 5-year DFS (86.5% vs. 74.4%, p=0.048; adjusted HR=0.281, 95% CI=0.107–0.735, p=0.010). No such benefit was observed for mucinous, endometrioid, or clear cell histologies.
  • For patients aged 65 years or older, lymphadenectomy was associated with longer DFS (adjusted HR=0.083, 95% CI=0.008–0.833, p=0.034).
  • In the subgroup of patients who did not receive adjuvant chemotherapy, the lymphadenectomy group demonstrated significantly improved 5-year DFS (94.6% vs. 76.7%, p=0.020). This effect was reduced in the chemotherapy subgroup, suggesting that adjuvant chemotherapy might mitigate the impact of lymphadenectomy on survival.

Lymph node metastasis was associated with worse DFS and OS (p=0.000). The number of harvested lymph nodes (categorized as <10 or >10) did not show a significant difference in survival.

Discussion The study concludes that, after adjusting for other prognostic variables, lymphadenectomy was not an independent prognostic factor for survival in patients with early-stage EOC. However, the findings suggest that the histologic subtype is associated with a survival benefit after lymphadenectomy, particularly in serous ovarian cancer. This leads to the recommendation that lymphadenectomy should be performed selectively, considering the histologic subtype and the role of subsequent adjuvant chemotherapy.

The current European Society for Medical Oncology–European Society of Gynaecological Oncology consensus considers lymphadenectomy a standard staging method for early-stage EOC, but this is based on low-level evidence (retrospective studies), and not all experts agree. Previous trials, such as the LION trial in advanced EOC, have shown no therapeutic role for lymphadenectomy, suggesting that the effects of occult lymph node metastasis can be reversed by adjuvant chemotherapy. This concept can be extrapolated to early-stage EOC, as highlighted by the study’s finding that the survival benefit of lymphadenectomy was more pronounced in patients not receiving adjuvant chemotherapy.

The study notes that lymph node metastasis rates vary by histology, being higher in serous histology (>10%) compared to low-grade endometrioid or mucinous histology (<2%). Therefore, lymphadenectomy may be primarily useful as a diagnostic tool in patients with an elevated risk of lymph node metastases, rather than universally, particularly where it might influence the decision for adjuvant chemotherapy. The survival benefit observed in serous EOC patients undergoing lymphadenectomy is likely due to the potential for stage-adapted adjuvant chemotherapy rather than the surgical excision of lymph nodes alone.

Strengths and Limitations: Strengths of the study include its large scale for evaluating the therapeutic role of lymphadenectomy in early-stage EOC, its reflection of recent clinical practice in a real-world setting, and an adequate follow-up period.

Limitations include its retrospective design, which introduces selection bias. The detailed surgical procedures for lymphadenectomy were not standardized, potentially affecting quality, and para-aortic lymphadenectomy was not consistently performed. Additionally, subclassification of mucinous histology was not possible, and the minimal use of targeted therapies (VEGF inhibitors, PARPi) in the cohort means their impact on survival was likely minimal and not assessed.

Conclusion In conclusion, this large-scale retrospective multicenter cohort study indicates that lymphadenectomy itself is not associated with an overall survival benefit in patients with clinically early-stage EOC after adjusting for prognostic variables. However, for patients with serous histology, lymphadenectomy may offer a survival benefit, likely attributed to the ability to provide stage-adapted adjuvant chemotherapy. The study suggests that lymphadenectomy should be selectively performed based on the histologic subtype, the patient’s medical condition, and the influence of the surgical findings on subsequent adjuvant chemotherapy decisions.

Introduction and Objectives

Pelvic lymph node dissection (PLND) is a standard and crucial component of staging protocols for gynecologic malignancies. Its primary purpose is to determine if a patient requires adjuvant therapy, as lymph node metastasis (LNM) is an important predictor of prognosis in these cancers. While the therapeutic benefits of PLND have not been definitively established, some studies indicate that it may improve the prognosis for patients with uterine cancer, especially those with intermediate to high risk of recurrence, with survival being dependent on the number of resected lymph nodes. Japanese guidelines for uterine and ovarian cancer specifically recommend PLND for accurate surgical staging due to the lack of a fully reliable preoperative LNM diagnostic system.

Historically, PLND was performed via laparotomy, but the introduction of laparoscopic approaches in 1989 by Dargent and Salvat marked a shift towards minimally invasive surgery (MIS) in gynecological oncology. Both laparoscopic and open surgeries have shown comparable numbers of resected lymph nodes in previous studies. More recently, robot-assisted surgery (RAS) has emerged as an advanced MIS technique, offering advantages such as improved 3D visualization, enhanced precision, better instrument control, and improved surgical ergonomics compared to conventional laparoscopic surgery (CLS).

Despite these advancements, the literature specifically comparing the surgical outcomes of PLND performed solely via different MIS modalities (RAS vs. CLS) remains limited. This study aimed to bridge this gap by comparing the surgical outcomes for pelvic lymph node dissection performed through conventional laparoscopic surgery (CLS) versus robot-assisted surgery (RAS) in patients with gynecologic malignancies.

Materials and Methods

This was a retrospective study that analyzed perioperative data from patients who underwent laparoscopic or robotic PLND for gynecologic cancer between January 2010 and December 2018 at a single hospital. The study included 731 patients with gynecologic malignancies who underwent transperitoneal PLND. Among these, 460 patients were in the CLS group, and 271 patients were in the RAS group. Indications for PLND included cervical, endometrial, and ovarian cancers.

Preoperative evaluations for all patients included physical examinations, vaginal pelvic examinations, chest radiography, computed tomography, and pelvic magnetic resonance imaging. All patients provided written informed consent.

All surgical procedures were performed by an expert surgeon and a dedicated MIS team. The da Vinci Surgical System was utilized for RAS, while a conventional two-dimensional laparoscopic system was used for CLS. Transperitoneal systematic PLND followed a six-step procedure: (1) port placement, (2) development of paravesical and pararectal spaces, (3) suspension of the lateral umbilical ligament, (4) dissection between the psoas major muscle and external iliac vessels, (5) dissection of the external iliac and obturator nodes, and (6) dissection of the internal iliac nodes. The dissection field for PLND extended from the bifurcation of the internal and external iliac arteries cranially to the deep circumflex iliac vein caudally. Lateral suprainguinal nodes were spared due to their low LNM risk and potential for lower-limb lymphedema. Sentinel lymph node navigation surgery was not routinely performed during the study period in Japan, so systematic lymph node dissection was the standard practice.

Data collection included patient characteristics (age, BMI, history of surgery, indication for surgery) and perioperative outcomes (estimated blood loss (EBL), operative time, number of removed lymph nodes, conversion to laparotomy, blood transfusion, and intra- and postoperative complications). Lymphedema was classified as Grade 2 or higher according to the International Society of Lymphology classification. Surgical data specifically analyzed focused on the intrapelvic PLND, as para-aortic lymph node dissection, if performed, was done via a conventional endoscopic extraperitoneal approach without the robot for both groups. Statistical analyses utilized the Chi-square test or Student’s t-test, with p < 0.05 considered statistically significant.

Results

Out of the 731 patients, 460 underwent CLS-PLND and 271 underwent RAS-PLND.

  • Patient Characteristics: The mean age was 50 ± 14 years in the RAS group and 53 ± 13 years in the CLS group (P < 0.01). The mean body mass index (BMI) was 23.4 ± 4.8 kg/m2 in the RAS group and 22.4 ± 3.6 kg/m2 in the CLS group (P < 0.01). The RAS group had a significantly higher proportion of patients with BMI > 30 kg/m2 (11.8% vs. 2.3%, P < 0.01). RAS was indicated more frequently for cervical cancer (46.0%) compared to CLS (31.3%), while CLS was more common for ovarian cancer (18.5% vs. 1.1%).
  • Operative Time and Blood Loss: The mean operative time was significantly shorter in the CLS group (46 ± 15 min) than in the RAS group (52 ± 15 min, P < 0.01). Similarly, EBL was lower in the CLS group (89 ± 78 mL) compared to the RAS group (110 ± 88 mL, P < 0.01).
  • Number of Resected Lymph Nodes: A significantly greater number of lymph nodes were resected in the RAS group (45 ± 17) than in the CLS group (38 ± 16, P < 0.01). This difference was particularly pronounced in patients with cervical cancer (RAS: 48 ± 18 nodes vs. CLS: 38 ± 16 nodes, P < 0.01), but no significant difference was found for endometrial cancer (RAS: 42 ± 16 nodes vs. CLS: 39 ± 16 nodes, P = 0.11). Specifically, the RAS group had a significantly higher number of external iliac and obturator lymph nodes removed on both sides.
  • Complications: The rates of Clavien-Dindo Grade ≥ III complications were comparable between the CLS group (8.7%) and the RAS group (6.3%, P = 0.17).
    • Intraoperative complications occurred in 6 (1.3%) patients in the CLS group (two obturator nerve injuries, four external iliac vein injuries) and 1 (0.4%) patient in the RAS group (external iliac artery injury). All were managed endoscopically without blood transfusion or conversion to laparotomy.
    • Postoperative complications occurred in 34 (7.4%) patients in the CLS group and 16 (5.9%) in the RAS group, with no significant difference between the groups (P = 0.43). The most common postoperative complications were lower-extremity lymphedema (CLS: 4.1%, RAS: 3.7%) and symptomatic lymphoceles (CLS: 3.3%, RAS: 2%).

Discussion

PLND remains a vital part of staging gynecologic malignancies, even as less radical surgeries become more common. A key finding of this study is the significantly higher number of lymph nodes dissected in the RAS group compared to the CLS group, especially in cervical cancer patients. The improved technology of the da Vinci robotic system, offering a greater range of instrument movement, enhanced dexterity, and superior 3D visualization, may contribute to this ability to resect more lymph nodes. While previous meta-analyses have shown comparable lymph node counts between CLS and RAS for endometrial cancer, some studies indicate higher counts with RAS for cervical cancer, which aligns with this study’s findings. Although RAS removed more external iliac and obturator lymph nodes, there was no observed difference in the dissection of internal iliac lymph nodes, which are more challenging to access.

The study’s findings on operative time and complications generally align with systematic reviews and meta-analyses, which suggest RAS is associated with longer operative times but comparable complication rates. However, this study found lower blood loss with CLS, a discrepancy attributed to the specific devices used, as the CLS employed a suction irrigator probe with a built-in monopolar electrode for immediate bleeding detection and hemostasis. Despite this, the observed difference in blood loss (approx. 20 mL) was considered clinically acceptable.

Lymphatic complications such as lymphoceles and lower-extremity lymphedema occurred at rates comparable to those reported in other studies, and there was no significant difference in their incidence between the CLS and RAS groups. The practice of inserting a retroperitoneal drain at the end of surgery was noted, primarily as a rapid indicator of postoperative bleeding rather than for lymphocele prevention.

The surgeon’s learning curve and experience are crucial factors influencing the number of retrieved lymph nodes. For robotic PLND, a proficient operative time was achieved after 12 cases, a significantly lower number than the 55 cases reported in a previous study. This faster learning curve for RAS in this study might be attributed to the surgeons’ extensive prior experience with laparoscopic PLND, as the procedures and surgical steps are similar.

Limitations of this study include its retrospective design, which introduces the possibility of selection bias based on surgeon experience and preferences. The prolonged interval between the introduction of laparoscopic and robotic PLND at the center could also lead to differences in surgeon proficiency. However, the study’s strength lies in being the first to compare surgical outcomes of PLND alone between RAS and CLS in gynecologic malignancies.

Conclusion

In conclusion, this study found that robot-assisted surgery (RAS) for pelvic lymph node dissection (PLND) was associated with significantly longer operative times and greater estimated blood loss compared to conventional laparoscopic surgery (CLS). Despite this, RAS resulted in the resection of a significantly higher number of lymph nodes. While the direct impact of the number of dissected lymph nodes on prognosis remains unclear, the increased yield with RAS is a notable finding. The rates of major complications were comparable between the two minimally invasive approaches.

The study highlights that RAS offers a benefit in terms of lymph node yield, particularly in cervical cancer, which could be attributed to its technological advantages in visualization and dexterity. Further prospective randomized controlled trials are needed to comprehensively evaluate postoperative pain and quality of life outcomes associated with minimally invasive PLND techniques.

Endometrial carcinoma is a prevalent gynecologic cancer, particularly in high-income countries, with its rising incidence linked to factors like obesity. Accurate surgical staging is paramount for guiding subsequent adjuvant radiation and chemotherapy decisions.

Traditionally, systematic pelvic and para-aortic lymphadenectomy (LND) was the standard for nodal assessment in gynecologic cancers, as recommended by the International Federation of Gynecology and Obstetrics (FIGO). However, this extensive procedure is associated with considerable morbidity, including systemic complications (such as chest infections, thrombo-embolic events, and cardiac events) and specific long-term complications like lymphedema and lymphocyst formation. One retrospective study on LND in gynecologic oncology reported an overall complication rate of 42.4%, with intra-operative, acute post-operative, and long-term rates of 26.1%, 11.0%, and 14.0%, respectively. Despite these rates, that study concluded that lymphadenectomy can be performed safely. Factors like laparotomy, positive lymph nodes, and operative time exceeding 240 minutes were identified as significant predictors of overall complications.

In response to the morbidity of systematic LND, SLN biopsy has emerged as a less invasive and highly accurate alternative. It has shown to be a viable replacement for complete LND, effectively avoiding complications associated with full dissection. SLN analysis is also more sensitive in detecting nodal disease, including micrometastases and isolated tumor cells, compared to conventional pathological examination of full lymphadenectomy specimens.

Despite these advantages, standard laparoscopic SLN dissection can be technically challenging, especially in obese patients, a significant demographic among endometrial cancer patients. The current study investigates vNOTES, a minimally invasive surgical technique that utilizes vaginal surgical access, thereby eliminating the need for abdominal incisions and the visible scars associated with them. The authors highlight several theoretical advantages of a retroperitoneal vNOTES SLN dissection: it is less invasive, allows for operation without the Trendelenburg position (anesthetic advantage, especially for obese patients who often face ventilation challenges), and follows the natural lymph node trajectory from caudal to cranial, potentially reducing the risk of missing sentinel nodes.

Methodology

This study was designed as a prospective, multicenter case series. Data were collected from 64 women with histologically confirmed early-stage endometrial carcinoma who were candidates for surgical staging with SLN removal. The surgical procedures were performed by four experienced surgeons across four different hospitals in Switzerland, USA, Brazil, and Belgium between March 2016 and May 2023.

The surgical technique involved a transvaginal retroperitoneal vNOTES approach. Patients were placed in the dorsal lithotomy position, allowing for conversion to standard laparoscopy if needed. After prophylactic antibiotics and Foley catheter placement, indocyanine green (ICG) was injected into the cervix to facilitate SLN mapping. Access to the obturator fossa was gained either through bilateral incisions in the lateral vaginal fornix or via a single anterior midline incision in the vaginal mucosa, based on the surgeon’s preference. A vNOTES port was then inserted to create a sealed retroperitoneal space, followed by CO2 insufflation.

Key anatomical structures such as the ureter, iliac bifurcation, internal and external iliac artery and vein, and the obturator nerve were identified. Sentinel lymph nodes were identified bilaterally using near-infrared light (ICG fluorescence) and then endoscopically removed. This entire procedure was performed transvaginally without any abdominal incisions. Following the SLN dissection, all patients underwent a vNOTES hysterectomy with bilateral salpingo-oophorectomy. Postoperative follow-up was at least 6 weeks.

Key Findings

The study successfully enrolled 64 patients. The median age was 69.5 years, and the median body mass index (BMI) was 26 kg/m2, with a notable proportion of obese (28%) and morbidly obese (6%) patients included.

Surgical outcomes were promising:

  • The median total surgical time was 126 minutes, and the median estimated blood loss was 80 mL.
  • Bilateral sentinel nodes were successfully identified in 97% of cases (62 out of 64), with unilateral identification in the remaining two cases.
  • On average, three sentinel nodes were resected per patient.
  • Pathological analysis revealed positive sentinel nodes in 4 patients (6%), with 3 cases showing isolated tumor cells and 1 case with macrometastasis without capsular rupture.
  • 30% of patients (19 out of 64) were discharged on the same day of surgery, while for others, the median hospital stay was 2 days.
  • The median visual analog scale (VAS) pain score 24 hours postoperatively was reported as 1 out of 10, indicating low postoperative pain.

Regarding complications:

  • A total of 10 perioperative or short-term postoperative complications were reported.
  • Bladder injury occurred in three cases (5%). Two were managed conservatively with a Foley catheter, and one required surgical repair; all three cases showed complete recovery and no sequelae after 6 weeks.
  • One patient required surgical reintervention due to bleeding 48 hours post-surgery, which was managed laparoscopically.
  • Other reported complications included transient adductor muscle paresis (presumed obturator nerve neuropraxy) in one case, a lacerated obturator vein repaired during surgery, and a femoral deep vein thrombosis with a vaginal vault hematoma developing 3 weeks post-surgery.
  • There were no conversions to laparotomy, and only one conversion to laparoscopy was necessary due to bleeding.
  • Importantly, no complications led to delays in subsequent adjuvant therapy.

Discussion and Clinical Implications

The study successfully demonstrates the feasibility of vNOTES retroperitoneal sentinel node resection for early-stage endometrial cancer, showing a high success rate for bilateral node identification. The authors suggest that the efficacy of this approach is at least comparable to the current standard laparoscopic or robotic ICG sentinel detection, which has a sensitivity of 92.5%.

The benefits of vNOTES, extrapolated from studies on benign indications, include shorter hospitalization periods, less postoperative pain, and the absence of trocar-related complications. The approach is particularly advantageous for obese patients, as it eliminates the need for the Trendelenburg position, simplifying anesthesia management. Furthermore, by dissecting lymph nodes from caudal to cranial, the technique aligns with the natural lymph flow, potentially reducing the risk of inadvertently removing secondary (non-sentinel) nodes. The shorter transvaginal distance to the sentinel nodes also lessens the impact of abdominal adiposity on surgical access.

However, the authors acknowledge several limitations. As a relatively new technique, vNOTES retroperitoneal lymph node dissection requires specialized surgical expertise in both vaginal and laparoscopic procedures, and it is associated with a significant learning curve. The 5% bladder injury rate observed in this early cohort is higher than the typical rates reported for laparoscopic hysterectomies (1-2.3%), which the authors attribute to the “developmental phase of the technique”. The retrospective nature of LND studies has been acknowledged in prior conversations, and the current study, being a case series, reinforces the need for further robust investigation. This study focuses only on low-grade endometrial cancers, and while there’s a theoretical concern about spilling cancerous cells with a vaginal approach, prior evidence from diagnostic hysteroscopy for early-stage endometrial carcinoma suggests no increased risk of positive peritoneal cytology.

Despite these limitations, the study’s strengths include its prospective, multicenter design involving multiple surgeons, which enhances the generalizability of the findings. The authors emphasize the need for larger-scale investigations, including prospective randomized controlled trials, to provide more definitive evidence on long-term safety and to enable accurate comparisons with existing laparoscopic and robotic cohort studies.

Conclusion

In conclusion, this first prospective publication on vNOTES retroperitoneal lymph node resection demonstrates its feasibility as a safe, reproducible, and less invasive alternative for staging early-stage endometrial carcinoma by experienced surgeons. While bilateral sentinel nodes were identified in 97% of cases with complication rates comparable to laparoscopic procedures, the technique’s learning curve and the observed bladder injury rate in this early series highlight areas for continued refinement. The potential benefits, especially for obese patients, and its anatomical approach to lymph node dissection, suggest that vNOTES holds promise as a valuable addition to minimally invasive gynecologic oncology, though further large-scale studies are warranted to fully establish its long-term safety and widespread applicability.

Summary sheet

Lymph node dissection (lymphadenectomy) is a crucial component in the staging and management protocols for gynecologic cancers, including cervical, endometrial, and ovarian cancers, as recommended by the International Federation of Gynecology and Obstetrics (FIGO). It provides essential information for guiding adjuvant therapy.

While its benefits vary, lymphadenectomy can lead to complications, which can occur during intra-operative, acute post-operative (within 29 days), or long-term (after 30 days) periods.

  • The overall complication rate can be substantial (42.4% in one study), though severe complications are low (13.5%).
  • Common complications include adjacent organ injury, significant blood loss, and specific issues like lymphocele and lymphedema. Symptomatic lymphocele and lymphedema occurred in 6.0% and 2.0% of patients, respectively, primarily in the long-term period.
  • Predictors for overall complications include laparotomy, positive lymph nodes, and operative time > 240 minutes. Age > 60 years is also a predictor for intra-operative complications.

Minimally invasive approaches like conventional laparoscopic surgery (CLS) and robot-assisted surgery (RAS) are increasingly common. While RAS may result in a greater number of resected lymph nodes, particularly in cervical cancer, CLS has been associated with shorter operative times and lower estimated blood loss for pelvic lymph node dissection (PLND). The rates of major complications were comparable between RAS and CLS for PLND.

The direct therapeutic impact of lymphadenectomy alone on survival is debated, varying by cancer type. For locally advanced cervical cancer, pre-treatment lymph node dissection does not provide a clear survival benefit but can aid in identifying the extent of metastasis, define the radiation field, and reduce radiotherapy complications, especially for larger lymph nodes (>2 cm). For early-stage epithelial ovarian cancer (EOC), while its diagnostic role is critical, the therapeutic impact of lymphadenectomy on overall survival (OS) or disease-free survival (DFS) is debated. However, it may offer a survival benefit for patients with serous histology EOC.

Lymph Node Ratio (LNR), which is the ratio of positive lymph nodes to the total number of resected lymph nodes, has emerged as a significant independent predictor of poorer prognosis (worse overall survival, progression-free survival, and disease-free survival) across various gynecologic cancers (cervical, ovarian, endometrial, and vulvar cancers).

Newer techniques like vaginal natural orifice transluminal endoscopic surgery (vNOTES) for sentinel lymph node dissection in endometrial cancer show promise, offering benefits such as less invasiveness and avoiding the Trendelenburg position, which is advantageous for obese patients. The assessment of standardized Critical Views of Safety (CVS) using video-based analysis and artificial intelligence (AI) is also being explored to enhance surgical safety and lymph node detection in minimally invasive sentinel lymph node dissection.

Overall, while lymphadenectomy is essential for staging and treatment planning, its therapeutic benefits depend on cancer type and histology, with a growing emphasis on minimizing morbidity through selective approaches and advanced techniques.

Podcast

Slides for a Powerpoint Presentation

Slide 1: Introduction to Lymph Node Dissection (LND)

  • LND is a crucial component of staging protocols for various gynecologic cancers, as recommended by the International Federation of Gynecology and Obstetrics (FIGO).
  • It plays a diagnostic role in identifying lymph node metastases, which significantly influences treatment decisions, especially for adjuvant therapy.
  • The prognosis of patients with uterine cancer, particularly those at intermediate and high risk of recurrence, can be dependent on the number of lymph nodes resected.
  • Despite its importance, LND is associated with potential complications that can arise during intra-operative, acute post-operative, or long-term periods.

Slide 2: Types of Lymph Node Dissection

  • Pelvic and Para-Aortic Lymphadenectomy: This is the traditional method performed for comprehensive staging, especially for endometrial and ovarian cancers.
  • Sentinel Lymph Node (SLN) Assessment: An alternative and increasingly preferred method, particularly for low-risk early-stage cervical cancer (FIGO IA2) and for endometrial cancer where it is preferred.
  • SLN mapping is now recommended by the National Comprehensive Cancer Network (NCCN) for endometrial and cervical cancer, offering essential staging information with reduced patient morbidity compared to systematic lymphadenectomy.
  • However, for high-risk endometrial cancer and as a component of surgical staging for cervical cancer, complete lymphadenectomy may still be recommended by FIGO guidelines.

Slide 3: Overall Complication Rates

  • A retrospective study on pelvic and para-aortic lymphadenectomy in gynecologic oncology reported an overall complication rate of 42.4%.
  • Major complications (defined as Grade 3-5 according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0) occurred in 13.5% of all cases.
  • The rate of major complications varied by cancer type, with ovarian cancer having the highest rate at 21.9%, compared to 8.4% for cervical cancer and 8.8% for endometrial cancer.
  • Despite these observed rates, studies generally conclude that lymphadenectomy in gynecologic cancer surgery can be performed safely, with a low incidence of severe complications.

Slide 4: Intra-operative Complications

  • Intra-operative complications were observed in 26.1% of patients undergoing pelvic and para-aortic lymphadenectomy.
  • Common intra-operative complications include injury to adjacent organs (such as blood vessels, bowel, bladder, or ureters) and significant blood loss (defined as exceeding 1,000 mL).
  • Predictors for intra-operative complications were identified as age greater than 60 years, use of laparotomy, presence of positive lymph nodes, and operative time exceeding 240 minutes.
  • For sentinel lymph node dissection, intra-operative complication rates have been reported to be as low as 0.4%.

Slide 5: Acute Post-operative Complications

  • Acute post-operative complications, defined as those occurring within 29 days of surgery, were observed in 11.0% of patients.
  • These complications can include surgical site infections (such as cellulitis or wound infection), cystitis, sepsis, bleeding requiring relaparotomy for hemostasis, and venous thromboembolism (VTE).
  • VTE occurred in 0.8% of cases during the acute post-operative period, with all reported cases being pulmonary embolism.
  • In one study, no significant factors were found to be directly related to the occurrence of acute post-operative complications.

Slide 6: Long-term Complications

  • Long-term complications, defined as those occurring after 30 days post-surgery, were reported in 14.0% of patients.
  • Lymphocele formation and lower-limb lymphedema are specific post-operative complications commonly associated with lymphadenectomy.
  • Symptomatic lymphocele was identified in 6.0% of patients, with the majority of these cases exhibiting spontaneous regression. The incidence of asymptomatic lymphocele can range from 17.3% to 20.2%.
  • Symptomatic lymphedema occurred in 2.0% of patients, typically presenting as mild symptoms managed with self-bandaging and physical therapy. Previous studies reported higher lymphedema incidences (11.4-36.9%), potentially due to variations in reporting or symptom severity.
  • Long-term VTE, encompassing deep vein thrombosis and pulmonary embolism, occurred in 3% of patients.

Slide 7: Predictors of Complications

  • Surgical Approach: Laparotomy was identified as a significant independent predictor for both overall and intra-operative complications.
  • Lymph Node Status: Patients with positive lymph nodes had a higher overall and intra-operative complication rate compared to those with negative lymph nodes. Positive lymph node status often indicates more advanced disease, leading to more complex and longer surgical procedures.
  • Operative Time: Surgical procedures lasting over 240 minutes were significant independent predictors for overall and intra-operative complications.
  • Patient Age: Age over 60 years was identified as an independent predictor for intra-operative complications.

Slide 8: Lymph Node Ratio (LNR) as a Prognostic Factor

  • The Lymph Node Ratio (LNR), calculated as the ratio of positive lymph nodes to the total number of resected lymph nodes, provides a more accurate representation of the metastasis status compared to just the number of positive nodes.
  • A higher LNR is consistently associated with a worse prognosis across gynecological cancers, impacting Overall Survival (OS), Progression-Free Survival (PFS), and Disease-Free Survival (DFS).
  • This prognostic value holds true across various gynecological cancer types, including cervical, ovarian, endometrial, and vulvar cancers.
  • LNR’s predictive value has been shown to be superior to simply counting the number of removed or positive lymph nodes, highlighting its potential for incorporation into future staging systems.

Slide 9: LND in Locally Advanced Cervical Cancer

  • For locally advanced cervical cancer (FIGO stages IIB-IVA), lymph node metastasis is a significant prognostic factor.
  • A meta-analysis indicates that lymph node dissection before initial treatment does not significantly affect Overall Survival when compared to concurrent radiotherapy.
  • Pre-treatment LND also does not increase postoperative complications or cause delays in subsequent radiotherapy.
  • However, the removal of larger lymph nodes (>2 cm) can help define the radiation field more precisely and potentially decrease radiotherapy-related complications, as large nodes are difficult to eradicate with radiation alone.
  • LND provides the benefit of pathological evaluation of lymph node tissue and accurate surgical staging, leading to improved diagnostic accuracy (20-40% improvement over PET-CT findings).

Slide 10: LND in Early-Stage Epithelial Ovarian Cancer (EOC)

  • The therapeutic role of lymphadenectomy in clinically early-stage EOC remains debated, with inconsistent results from retrospective studies.
  • Overall, recent studies show no significant difference in 5-year DFS or OS between lymphadenectomy and non-lymphadenectomy groups in early-stage EOC.
  • However, lymphadenectomy was associated with survival benefits (improved DFS) in patients with serous histology, suggesting a selective approach based on histologic subtype.
  • Lymphadenectomy in EOC leads to longer operative times, higher estimated blood loss, and increased perioperative complication rates compared to non-lymphadenectomy procedures.
  • The benefit of LND may stem from its diagnostic role in guiding stage-adapted adjuvant chemotherapy, rather than direct surgical excision of occult tumors, as adjuvant chemotherapy can mitigate the effects of occult metastasis.

Slide 11: Conventional Laparoscopic Surgery (CLS) for PLND

  • CLS is a minimally invasive approach that has been successfully applied for pelvic lymph node dissection in gynecologic cancers since 1989.
  • It offers shorter operative times and lower estimated blood loss compared to Robot-Assisted Surgery (RAS) for pelvic lymph node dissection.
  • The rates of major complications (Clavien-Dindo Grade ≥ III) are comparable to RAS, suggesting similar safety profiles for severe events.
  • Postoperative complications, including symptomatic lymphocele and lower-extremity lymphedema, also show no significant difference when compared to RAS.

Slide 12: Robot-Assisted Surgery (RAS) for PLND

  • RAS is a newer minimally invasive technique offering distinct advantages such as improved 3D visualization, greater precision, enhanced dexterity, and improved surgical ergonomics.
  • In pelvic lymph node dissection, RAS allows for the resection of a significantly greater number of lymph nodes compared to Conventional Laparoscopic Surgery (CLS). This difference is particularly notable in cervical cancer.
  • Despite its technological advantages, RAS typically involves longer operative times and can have higher estimated blood loss compared to CLS, though the blood loss difference may be attributed to specific instrument usage.
  • Similar to CLS, RAS demonstrates comparable rates of major and overall postoperative complications, including lymphatic complications like lymphoceles and lymphedema.

Slide 13: vNOTES for Sentinel Lymph Node Dissection

  • Vaginal Natural Orifice Transluminal Endoscopic Surgery (vNOTES) is an emerging minimally invasive technique for sentinel lymph node dissection, particularly noted for endometrial cancer staging.
  • It offers unique advantages such as no visible abdominal scars, operating without the need for a Trendelenburg position (which is beneficial for obese patients), and following the natural lymph node trajectory from caudal to cranial.
  • The technique has shown high success, with bilateral sentinel nodes identified in 97% of cases in early-stage endometrial carcinoma.
  • Initial studies indicate favorable short-term outcomes including shorter hospitalization and less postoperative pain, with reported perioperative complications being managed effectively without long-term sequelae.

Slide 14: Critical Views of Safety (CVS) in SLN Dissection

  • To enhance surgical safety and standardize sentinel lymph node (SLN) dissection, Critical Views of Safety (CVS) criteria have been proposed, based on the identification of mandatory anatomical structures.
  • Three key criteria include visualizing the lateral pararectal space, lateral paravesical space, and the internal iliac artery.
  • While the lateral paravesical space (identified in 94% of videos) and pararectal space (62%) are frequently observed, the internal iliac artery has a lower assessment rate (32%), raising concerns about potentially missing sentinel lymph nodes in deeper anatomical areas.
  • Standardized assessment of these safety criteria aims to improve adherence to guidelines and enhance the overall efficacy of the SLN technique.

Slide 15: The Role of Artificial Intelligence (AI) in Surgical Safety

  • Video-based assessment of Critical Views of Safety (CVS) lays the foundation for developing artificial intelligence (AI) algorithms in gynecologic oncology.
  • These AI tools could automatically assess and document CVS in surgical videos, thereby enhancing surgical precision and outcomes.
  • AI can contribute to standardizing safety checklists across institutions and provide objective analysis of recommended surgical steps.
  • By quantifying and analyzing intra-operative events, AI algorithms can help optimize guideline adherence and identify new strategies to reduce operative risks, especially during the surgeon’s learning curve.

Slide 16: Impact on Patient Survival

  • While lymphadenectomy is crucial for staging, its direct impact on overall patient survival can vary and is often debated.
  • Patients who experience at least one complication after gynecologic surgery show a significantly lower 5-year survival rate compared to those without complications.
  • However, specifically in locally advanced cervical cancer, lymph node dissection before initial treatment has not shown a clear survival benefit over concurrent radiotherapy.
  • For early-stage epithelial ovarian cancer, lymphadenectomy generally does not improve overall survival, except potentially in specific histological subtypes like serous cancer, where it might guide adjuvant therapy.
  • The Lymph Node Ratio (LNR) is a strong prognostic indicator, with a higher LNR consistently associated with poorer OS, PFS, and DFS across various gynecologic cancers.

Slide 17: Balancing Staging with Morbidity

  • The primary role of lymphadenectomy remains accurate disease staging and guiding subsequent adjuvant therapy.
  • The shift towards Sentinel Lymph Node (SLN) dissection in suitable cases aims to provide essential staging information while significantly reducing patient morbidity associated with systematic lymphadenectomy.
  • Despite the benefits of less invasive techniques, complications like lymphocele and lymphedema are still concerns, though their symptomatic rates might be low.
  • The decision to perform lymphadenectomy, especially for early-stage EOC, should be selective, considering histologic subtype, patient performance, and the influence on subsequent chemotherapy decisions.

Slide 18: Future Directions and Research Needs

  • Further prospective randomized controlled trials are needed to validate the impact of lymph node dissection on survival, particularly in specific populations like locally advanced cervical cancer.
  • Research is essential to determine the optimal LNR threshold and the minimum lymph node removal threshold to guide adjuvant therapy choices and minimize morbidity.
  • The development and clinical validation of AI-driven tools for video assessment of Critical Views of Safety will enhance surgical quality, safety, and adherence to guidelines in minimally invasive procedures.
  • Larger, multi-institutional studies are necessary to provide more accurate comparisons between different minimally invasive techniques and determine long-term safety and outcomes.

Slide 19: Conclusion

  • Lymph node assessment is paramount for accurate staging and guiding treatment in gynecologic cancers, with evolving techniques aimed at balancing diagnostic precision and patient safety.
  • While systematic lymphadenectomy carries a notable complication rate, severe complications are rare, and selective application can be safe.
  • Newer minimally invasive techniques like Robot-Assisted Surgery (RAS) and vNOTES offer advantages in lymph node yield or patient recovery, demonstrating comparable or improved safety profiles for severe complications.
  • The Lymph Node Ratio (LNR) emerges as a critical prognostic factor across various gynecologic cancers, indicating the importance of comprehensive lymph node assessment.
  • Continued research, technological advancements (like AI), and tailored treatment strategies are essential to further refine lymph node management, improve patient outcomes, and reduce treatment-related morbidity.