Indocyanine green for intraoperative ureteral identification in gynecologic surgery: A preliminary systematic review of feasibility, safety, and surgical outcomes

Background Intraoperative ureteral injury, although uncommon, can result in significant morbidity and medicolegal consequences, particularly during complex gynecologic procedures such as endometriosis excision and prolapse repair. Conventional ureteral identification techniques, including stents and methylene blue, have recognized limitations. Indocyanine green (ICG) with near-infrared fluorescence (NIRF) imaging enables real-time ureter visualization, but clinical evidence remains scattered.

To systematically evaluate the feasibility, safety, and outcomes of intraureteral ICG for ureteral identification in gynecologic surgery. Search Strategy A systematic literature search of multiple databases was performed for studies published between 2000 and 2025 using keywords related to ICG, ureter, gynecologic surgery, and intraoperative fluorescence. Selection Criteria Studies reporting intraureteral ICG use for ureteral identification during gynecologic surgery were eligible. Studies involving fewer than 10 patients were excluded. Data Collection and Analysis Data were extracted on ureter visualization success, ureteral injury, ICG-related complications, and operative outcomes. Risk of bias was assessed using the ROBINS-I, and certainty of evidence was evaluated using GRADE.

Of 778 records identified, seven studies comprising 299 patients met the inclusion criteria. All studies reported successful ureter visualization, with no ureteral injuries or ICG-related complications. Secondary outcomes, including estimated blood loss and operative time, were inconsistently reported, with very low certainty of evidence.

Intraureteral ICG appears to consistently enable safe, real-time visualization during gynecologic surgery, including complex cases. Although safety and visualization outcomes are encouraging, the evidence is limited. Prospective observational studies with standardized outcome reporting are needed to inform future practice. Prospero Registration CRD420251110017. 1 INTRODUCTION Intraoperative ureteral injury, although uncommon, remains one of the most serious complications in gynecologic surgery,1 because of its potential for long-term morbidity,2 delayed diagnosis,3 and medicolegal repercussions.4 Risk is increased during complex pelvic operations such as endometriosis resection, pelvic organ prolapses (POP) repairs, oncologic procedures, and reoperations where dense adhesions or distorted anatomy obscure the ureters.5 Conventional techniques of ureteral identification, including prophylactic stent placement, intraoperative cystoscopy, and dye agents such as methylene blue, have notable limitations.6, 7 Specifically, the sensitivity of these techniques ranges from 63% to 91%, indicating imperfect detection of injury.8 Indocyanine green (ICG) is a sterile, water-soluble fluorescent dye that emits infrared light when excited by near-infrared energy. After binding to plasma proteins, it can be visualized using near-infrared fluorescence (NIRF) imaging. When instilled directly into the ureters via retrograde catheterization or stenting, ICG enables real-time visualization of ureteral anatomy and peristalsis during surgery.9 Retrograde instillation via a cystoscopic catheter or stent allows dynamic visualization of the ureter course throughout dissection.10 An increasing number of surgeons have reported successful use of ICG in robotically assisted and laparoscopic procedures,11 particularly in patients with distorted pelvic anatomy resulting from previous surgical scarring.12 Despite growing clinical interest, the existing evidence remains fragmented, consisting primarily of small observational studies, case series, and individual reports with variable dosing strategies, visualization techniques, and outcome measures. A recent systematic review and meta-analysis compared retrograde intraureteral ICG with ureteral stents for reducing urinary tract complications during pelvic surgery and suggested that ICG may provide comparable ureteral identification with fewer urinary tract complications.13 Despite these promising findings, the underlying gynecologic literature remains heterogeneous, consisting largely of small observational studies with variable dosing strategies, visualization techniques, and outcome reporting. This report therefore seeks to synthesize the current evidence regarding the feasibility, safety, and operative outcomes of intraureteral ICG for ureter visualization in gynecologic surgery and to identify areas for standardization and future research. 2 MATERIALS AND METHODS 2.1 Study protocol This systematic review was conducted in accordance with a predefined protocol registered with the International Prospective Register of Systematic Reviews (PROSPERO registration number: CRD420251110017). It was originally registered as a meta-analysis protocol; however, because of heterogeneous and limited eligible studies, a quantitative meta-analysis was not feasible, and the study was conducted and reported as a systematic review instead. No other significant deviations from the registered protocol were made. The reporting of this review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines.14 2.2 Search strategy A comprehensive literature search was conducted on July 6, 2025, using the Texas Medical Center (TMC) Library portal to PubMed (via NCBI), Embase and Scopus (via Elsevier), and the Cochrane Library (via Wiley). Studies published between January 2000 and July 2025 were eligible for inclusion, corresponding to the period when NIRF imaging became clinically available for intraoperative use. Only articles published in English were included. Search terms included a combination of key terms related to ICG, ureter, gynecologic surgery, and intraoperative fluorescence. The primary search string was: (“Indocyanine Green” OR “ICG”) AND (“ureter” OR “ureteral”) AND (“gynecologic surgery” OR “hysterectomy” OR “endometriosis” OR “robotic surgery” OR “laparoscopic surgery”) AND (“intraoperative” OR “fluorescence”). A secondary search was conducted on July 19, 2025, using the following terms: (“Indocyanine Green” OR “ICG” OR “Firefly”) AND (“vNOTES” OR “natural orifice” OR “ureteral” OR “stent” OR “endometriosis” OR “gynecologic” OR “hysterectomy” OR “robotic surgery” OR “laparoscopic surgery”). From this search, 200 records were screened at the title and abstract level; one article met criteria for full-text review but did not meet the inclusion criteria. No additional eligible studies were identified. 2.3 Eligibility criteria Studies were eligible for inclusion if they included adult women (≥18 years) undergoing gynecologic surgery, including laparoscopic, robotic, vaginal natural orifice transluminal endoscopic surgery (vNOTES), or oncologic procedures, with ICG for intraoperative ureter identification. Eligible study designs included randomized controlled trials, prospective or retrospective cohort studies, case–control studies, and case series with 10 or more patients. Studies that did not report outcomes related to ureter visualization or injury were excluded. Case reports and small case series (<10 patients) were excluded from the systematic review. When relevant, they were examined separately to provide contextual information and summarized in a separate table. Systematic reviews, narrative reviews, editorials, protocols, dissertations, technical reports, animal studies, and conference abstracts without outcome data were also excluded from synthesis but screened for relevant citations. 2.4 Study selection All search results were imported into Zotero (v6.0) de-duplication and then uploaded to Rayyan15 for screening in two levels: (1) title and abstract screening, and (2) full-text screening. Two reviewers independently screened all records under blinded conditions. Discrepancies were resolved by consultation with a third reviewer. Full-text articles were assessed using predefined eligibility criteria. Reasons for full-text exclusion and the study selection process are summarized in the PRISMA 2020 flow diagram14 (Figure 1). 2.5 Data extraction Data were extracted by one reviewer and verified by a second reviewer (Table 1). Extracted variables included study characteristics, patient population, surgical approach, ICG administration details, and outcomes of interest. Primary outcomes included ureter visualization and intraoperative ureteral injury. Secondary outcomes included operative time, estimated blood loss (EBL), postoperative length of stay, and other reported perioperative outcomes. All data were extracted from published manuscripts and tables. | Study ID | Country | Study design | Sample size/comparator | Population details | Surgery type | ICG admin. methoda | ICG dose | |---|---|---|---|---|---|---|---| | Kim, 20235 | South Korea | Retrospective single-center single-surgeon case series | 26; no comparator | At high risk of ureteral injury due to pelvic pathologies or reconstructive surgery | Laparoscopic or robot-assisted | Via open-ended catheter placed using a hysteroscope | 25 mg in 10 mL sterile water; 5 mL per ureter with 1–2-min dwell time | | Radilla, 202511 | USA | Retrospective single-center cohort study comparing junior versus senior surgeons | 92; junior surgeons versus senior surgeon | With advanced-stage (rASRM stage III/IV) endometriosis, including obliterated cul-de-sac | Robot-assisted laparoscopic endometriosis excision | Via cystoscopically placed bilateral ureteral stents | 25 mg in 10 mL saline; 5 mL per ureter with 1-min dwell time | | Jun, 202418 | South Korea | Retrospective single-center single-surgeon case series | 15; no comparator | With apical vaginal prolapse with anterior and posterior compartment prolapse (POP-Q Stage 2b–4), including complex anatomy (adhesions, obesity) | Robot-assisted sacrocolpopexy with or without hysterectomy and adnexectomy | Via open-ended catheter placed using a hysteroscope | 25 mg ICG in 10 mL sterile water; 5 mL per ureter with 1-min dwell time | | Park, 201519 | USA | Retrospective single-center case series | 10; no comparator | With Stage II–IV endometriosis undergoing ureterolysis at high risk of ureteral injury | Robot-assisted laparoscopic endometriosis excision | Via cystoscopically placed bilateral ureteral stents | 8 mL of 1.25 mg/mL ICG solution per ureter | | Yang, 202520 | USA | Retrospective single-center single-surgeon case series | 96 out of 298 patients were administered ICG; no comparator | Including endometriosis, abnormal uterine bleeding, fibroids, and pelvic organ prolapse | RA-vNOTES for hysterectomy (95.97% of patients), endometriosis excision, and other gynecologic procedures | Via cystoscopically placed bilateral ureteral stents | Not specified | | Centini, 202421 | Italy | Prospective cohort study with 1:1 propensity score matching | 20; (10 in ICG group, 10 in non-ICG matched group) | With deep infiltrating endometriosis with suspected ureteral involvement of the uterosacral ligament | Laparoscopic deep endometriosis excision with ureterolysis | Via cystoscopically placed bilateral ureteral stents | 4–5 mL of 2.5 mg/mL ICG solution per ureter | | Lovell, 202422 | USA | Retrospective single-center single-surgeon case series | 50; no comparator | With all stages of endometriosis | vNOTES for total hysterectomy and endometriosis excision | Via cystoscopically placed bilateral ureteral stents | 5 mL of 2.5 mg/mL ICG solution per ureter | - Abbreviations: ICG, indocyanine green; POP-Q, Pelvic Organ Prolapse Quantification; rASRM, revised American Society for Reproductive Medicine; RA-vNOTES, robot-assisted vaginal natural orifice transluminal endoscopic surgery. - a All ICG administration methods were intraureteral and instilled before surgery. 2.6 Risk of bias assessment Risk of bias was assessed independently by two reviewers using the Risk Of Bias In Non-randomized Studies–of Interventions (ROBINS-I) tool.16 Bias was evaluated across seven domains, and the overall risk of bias was determined based on the highest-risk domain. Discrepancies were resolved by discussion. Results are summarized using traffic-light plots (Figure 2). 2.7 Certainty analysis Certainty of evidence for commonly reported outcomes was assessed using the GRADE framework.17 Starting from low certainty for observational studies, domains of risk of bias, inconsistency, indirectness, imprecision, and publication bias were evaluated. Final certainty ratings are reported in the Supplementary material (Table S1). 3 RESULTS 3.1 Study selection A total of 860 records were identified through database searches. After removal of 82 duplicates, 778 unique records were screened at the title and abstract levels. Of these, 765 records were excluded, and 13 full-text articles were assessed for eligibility. Following full-text screening, six reports were excluded for the following reasons: non-surgical context (n = 1), not a formal study (video or abstract only; n = 3), and ineligible population (n = 2). Ultimately, seven articles met all the inclusion criteria and were included in the systematic review. The study selection process is presented in Figure 1. 3.2 Study characteristics Seven studies published between 2015 and 2025 were included.5, 11, 18-22 All evaluated intraoperative ureter visualization using ICG in women undergoing gynecologic surgery. Most studies were retrospective, single-center case series; one study11 was a retrospective cohort comparing operative performance between junior and senior surgeons using ICG, and one21 employed a prospective, matched cohort design. Surgical indications included high-risk gynecologic procedures such as excision of Stage III/IV endometriosis (per American Society for Reproductive Medicine criteria), ureterolysis for suspected uterosacral ligament involvement, hysterectomy for abnormal uterine bleeding or fibroids, and apical prolapse repair involving complex anatomy. Some studies included patients across all endometriosis stages, whereas others focused exclusively on deep infiltrating endometriosis. Indocyanine green was most commonly administered via cystoscopically placed bilateral ureteral stents. In a subset of studies,5, 18 dye was instilled through open-ended catheters inserted using a hysteroscope. Key study characteristics are summarized in Table 1. 3.3 Risk of bias Using the ROBINS-I tool, all included studies were assessed as having moderate or serious overall risk of bias (Figure 2). The most common sources of bias were confounding, participant selection, lack of comparator groups, and limitations inherent to retrospective study designs. Overall risk of bias was assigned based on the highest risk domain for each study. No study was excluded because of risk of bias. 3.4 Ureteral visualization and injury rates All seven included studies reported successful intraoperative ureteral visualization using ICG, with a cumulative total of 299 patients. No ureteral injuries were reported. Subgroup analysis by surgical approach or indication was not performed due to uniform visualization success and absence of injury events. In the study by Yang et al.,20 one ureter transection occurred among the 202 patients who did not receive ICG administration during robot-assisted vNOTES for Stage IV endometriosis. Following implementation of routine intraureteral ICG instillation via bilateral stents, no further ureteral injuries were observed in more than 100 subsequent cases, including 20 with Stage IV endometriosis. 3.5 Surgical complications No intraoperative or postoperative complications were directly attributed to ICG administration in any included study. Mild urinary complications not attributed to ICG, including hematuria, urinary tract infection (UTI), urinary retention, and dysuria, were reported across several studies. Radilla et al.11 reported one case each of hematuria fever, pneumothorax, and UTI in the junior group, and two cases of urinary retention, three blood transfusions, and two cases of sepsis in the senior group. Centini et al.21 reported one case of transient hematuria. Lovell et al.22 reported four patients with postoperative urinary symptoms, three of whom were treated for suspected UTI. One patient required temporary Foley placement for suspected bladder injury, though no ureteral trauma was identified. 3.6 Secondary outcomes 3.6.1 Reported estimated blood loss A full summary of commonly reported secondary outcomes, including EBL, operative time, and postoperative stay, is presented in Table 2. Because secondary metrics were not separately reported for the 96 patients who received ICG, Yang et al.20 is excluded from secondary outcome results. | Study | Sample size | Reported EBL, mL | Operative time, min | Postoperative stay, day | |---|---|---|---|---| | Kim | 26 | 176.9 (100–500) | 189.8 (120–375) | 4.1 (3–6) | | Radilla | 44/48 | 100 [50–200]/150 [50–238] | 233 [187–316]/348 [255–460] | 1 [0–1]/2 [1–3] | | Jun | 15 | 153.3 ± 69.4 | 346.0 ± 37.9 | 5 (4–7) | | Park | 10 | 23 | 121 | 1 | | Centini | 10 | Not reported | 147.6 ± 14.1 | Not reported | | Lovell | 50 | 25 [25–50] | Not reported | Not reported | - Abbreviation: EBL, estimated blood loss. - a Data are presented as mean (range), median [interquartile range], mean ± standard deviation, or mean alone. Estimated blood loss was reported in five studies and varied substantially. Park et al.19 reported a mean EBL of 23 mL in patients with Stage II–IV endometriosis, while Lovell et al.22 reported a median EBL of 25 mL (interquartile range [IQR] 25–50 mL). Jun et al.18 reported a mean ± standard deviation for EBL of 153.3 ± 69.4 mL in patients undergoing prolapse surgery. Kim et al.5 reported a mean EBL of 176.9 mL (range 100–500 mL) in a mixed surgical cohort. Radilla et al.11 reported median EBL of 100 mL (IQR 50–200 mL) for junior surgeons and 150 mL (IQR 50–238 mL) for senior surgeons. Centini et al.21 did not report EBL. Overall, reported blood loss ranged from 23 to 500 mL. 3.6.2 Operative time Operative time was reported in five studies, though metrics varied. Jun et al.18 and Centini et al.21 reported mean operative times of 346.0 ± 37.9 min and 147.6 ± 14.1 min, respectively. Kim et al.5 reported a median of 189.8 min (range 120–375 min), while Park et al.19 reported a mean of 121 min. Radilla et al.11 reported median operative times of 233 min (IQR 187–316 min) for senior surgeons and 348 min (IQR 255–460 min) for junior surgeons. Lovell et al.22 did not report operative duration. Overall, operative times ranged from around 121–460 min, depending on surgical complexity, case type, and reporting style. 3.6.3 Postoperative stay Length of stay was reported in four studies. Kim et al.5 and Jun et al.18 reported mean stays of 4.1 days (range 3–6 days) and 5 days (range 4–7 days), respectively. Radilla et al.11 reported a median stay of 1 day (IQR 0–1 day) for junior surgeons and 2 days (IQR 1–3 days) for senior surgeons, with same-day discharge rates of 45.5% and 18.8%, respectively (P = 0.91). Park et al.19 reported a mean stay of 1 day. Centini et al.21 and Lovell et al.22 did not report length of stay. 3.6.4 Less commonly reported outcomes Other secondary outcomes were inconsistently reported. Kim et al.5 described an ICG instillation time of 10–20 min, while Lovell et al.22 reported a median stent placement time of 229 s (IQR 180–260 s). Lovell et al.22 also demonstrated significantly reduced ureter identification time with ICG (1 s versus 17 s without ICG; P < 0.001). Centini et al.21 reported significantly greater ureterolysis extent and operative time in the non-ICG group (P < 0.001). 3.7 Certainty analysis Overall certainty of effect evidence was rated as very low due to methodologic limitations. Contributing factors included moderate to serious risk of bias, heterogeneity in study design and reporting, and imprecision related to small sample sizes and rare outcome events. A summary of GRADE assessments is presented in the Supplementary material (Table S1). 4 DISCUSSION 4.1 Summary of visualization and injury rate findings This systematic review assessed the application of ICG NIRF for ureteral visualization intraoperatively during gynecologic surgery. Among seven studies comprising 299 patients and differences in surgical type, population details, and methods of ICG administration, ICG consistently enabled ureter visualization with no reported ureteral injuries. These findings support the feasibility of ICG use in complex gynecologic surgery, including those involving challenging pelvic anatomy such as endometriosis and adhesions. Radilla et al.11 demonstrated that ICG-guided visualization may enable less experienced surgeons to achieve outcomes comparable to those of senior surgeons, suggesting ICG's potential role as both a surgical adjunct and an educational tool in complex gynecologic surgery. Additionally, Yang et al.20 indirectly compared outcomes between patients undergoing surgery with and without ICG. Among 298 patients, 202 underwent procedures without ICG and experienced one ureteral injury, whereas no ureteral injuries occurred among the 96 patients who had received ICG. Both groups were treated at the same institution by the same surgeon using similar operative protocols. Although the present study highlights the potential utility of ICG in ureteral identification, ureteral injury was a rare event, and larger comparative studies are needed to determine whether ICG use meaningfully reduces the risk of ureteral injury. Historical data from large gynecologic surgery cohorts report ureteral injury rates between 0.3% and 2%, depending on surgical approach and indication (Table S2).24-27 In the studies included in this review, no ureteral injuries were reported among patients undergoing ICG-assisted procedures, including several high-risk cases. However, most included studies were relatively small and non-comparative, and ureteral injury is a rare outcome; therefore, these findings should be interpreted cautiously and cannot establish whether the absence of injuries is attributable to ICG use. A prospective study by Spagnolo et al.23 evaluated the impact of intraureteral ICG-guided ureteral mapping on surgeon workload using the Surgery Task Load Index scoring system.23 After adjustment for the learning curve, surgeons reported reductions in mental, physical, and temporal demand with ICG use. Although this study did not include a direct comparison of ureteral visualization or injury rates with a control group, it supports the feasibility and ergonomic benefits of ICG in complex gynecologic cases. 4.2 Complications and safety profiles Across all included studies, no intraoperative or postoperative complications were directly attributed to ICG administration. Reported urinary complications, including transient hematuria, UTI, or postoperative retention, were attributed to surgical manipulation or patient-specific factors rather than ICG use. These results support the safety of intraureteral ICG when administered via cystoscopic stents or open-ended ureteral catheters. Indocyanine green provides nonthermal, fluorescence-based ureteral mapping that allows dynamic visualization of ureteral course and peristalsis. In contrast, lighted ureteral stents rely on intraluminal illumination and require additional instrumentation and procedural steps, with associated costs and catheter-related complications reported in complex pelvic surgery.28 Although rare, allergic reactions to ICG have been reported in individual cases ranging from urticaria or hypotension, to anaphylaxis (Table 3). No such events were observed in the studies included in this review, highlighting the importance of patient screening and allergy assessment before ICG administration. | Study | Procedure/setting | Reaction type | Approximate frequency | |---|---|---|---| | Sasaki et al.29 | Abdominal surgery (IV ICG 5 mg bolus) | Immediate anaphylaxis | Single published case | | Papadia et al.30 | SLN mapping with ICG (interstitial injection) | Anaphylaxis | ~0.4% in cohort (1/234) | | Song et al.31 | Vascular/video angiography (IV ICG bolus) | Anaphylactic shock | Two isolated case reports | | Hope-Ross et al.32 | Multiple IV uses | Mild to severe reactions | Mild 0.15% (3/1923), moderate 0.2% (4/1923), severe 0.05% (1/1923) | - Abbreviations: ICG, indocyanine green; IV, intravenous; SLN, sentinel lymph node. 4.3 Methodologic limitations and evidence certainty The overall certainty of evidence was rated as very low due to methodologic limitations across studies. All included studies were observational in design, with most being small, retrospective case series and exhibiting moderate to serious risk of bias. Secondary outcomes, such as operative time, estimated blood loss, and postoperative recovery time were inconsistently reported, limiting quantitative analyses. Less commonly reported measures, including transfusion rates, hemoglobin drop, ICG instillation time, and ureter identification time, were available from only one or two studies. These limitations underscore the need for standardized outcome definitions and reporting frameworks in future investigations. 4.4 Additional evidence from case reports Apart from the seven primary articles, several case reports and small series further support the feasibility of intraureteral ICG in complex surgical scenarios (Table 4). These reports describe successful ureter visualization in patients with advanced endometriosis, distorted pelvic anatomy, previous pelvic surgery, or crossed renal ectopia. Across these cases, ICG was typically administered via retrograde ureteral catheterization or mono-J stents for fluorescence visualization, and no ureteral injuries or dye-related complications were reported. Most patients had favorable short-term outcomes, including same-day discharge and symptom resolution at follow-up. | Authors | Country | Patient age/Case description | ICG administration route/Dose | ICG timing | Surgery type | Fluorescence visualization outcome | Complications | Follow-up outcomes | |---|---|---|---|---|---|---|---|---| | Carbone et al.9 | USA | 3 patients: leiomyomata, prolapse, adhesions, post-hysterectomy | 25 mg ICG in 10 mL sterile water, 5 mL injected per ureter via 6-Fr catheters | Before robotic surgery; sustained visibility intraoperatively | Robotic hysterectomy, USLS, sacrocolpopexy | Consistent bilateral ureter visualization via NIR throughout all cases | None | All discharged same day; no immediate complications noted | | Joukhadar et al.33 | Germany | 29-year-old with DIE and ipsilateral crossed renal ectopia (residual renal function 27%) | Transurethral via mono-J stents; 4 mL of ICG (2.5 mg/mL) | Pelvic kidney visible in 4 min; complete ureter in 7–8 min | Robotic resection of DIE, adhesiolysis, ureterolysis, pelvic dissection | Entire ureter successfully visualized | None | Normal renal function; adequate postoperative course | | Thigpen et al.12 | USA | 43-year-old G0 with Stage IV endometriosis, previous failed hysterectomies | Retrograde injection via bilateral 5-Fr ureteral catheters; dose not specified | Used intraoperatively during robotic surgery; no exact timing reported | Robotic-assisted TLH, BSO, ureterolysis, bowel resection, endometriosis resection | Clear visualization of ureters throughout the procedure | None | Complete pelvic pain resolution at 3-week follow up | | Menezes et al.34 | Brazil | Case 1: multifibroid uterus; Case 2: advanced endometriosis with rectal involvement | Direct ureteral injection and vaginal application; dose not specified | Intraoperative visualization during laparoscopic hysterectomy and dissection | Laparoscopic hysterectomy and advanced endometriosis excision | Improved visualization of ureters and rectovaginal plane | None | Positive outcomes; no intra/post-operative complications reported | | Rajanbabu et al.35 | India | 56-year-old with a 10.5 × 14.5 × 13 cm3 multiloculated endometriotic cyst, dense adhesions to omentum, bowel, bladder, and pelvic wall | Intraureteral; 5 mL of 0.5% ICG via 6-Fr ureteral catheters | Before start of robotic surgery | Robotic-assisted hysterectomy with bilateral salpingo-oophorectomy | Bilateral ureters clearly visualized throughout the case using Firefly NIR | None | No intra/post-operative complications; ureters preserved | | Guan et al.36 | USA | 35-year-old with ovarian remnant syndrome post-hysterectomy and BSO; recurrent pelvic pain; previous advanced endometriosis | Retrograde instillation via bilateral ureteral catheters; dose not specified | During robotic-assisted surgery | Robotic-assisted resection of ovarian remnant and endometriosis with ureterolysis and bowel resection | Successful real-time ureter visualization facilitating safe dissection and excision | Postoperative pelvic abscess and pleural effusion | Prolonged recovery; patient disease-free post-discharge | | Carrubba et al.37 | USA | 61-year-old, G2P2002, large 14-cm cervical fibroid, right hydronephrosis, underwent robotic-assisted hysterectomy | ICG injected into preoperatively placed right ureteral stent; dose not specified | Before robotic-assisted laparoscopic surgery | Robotic-assisted total laparoscopic hysterectomy with bilateral salpingo-oophorectomy | Successful ureter identification under Firefly mode during challenging fibroid dissection | None reported | No ureteral injury; benign leiomyoma confirmed; uneventful recovery | - Abbreviations: BSO, bilateral salpingo-oophorectomy; DIE, deep infiltrating endometriosis; ICG, indocyanine green; NIR, near-infrared; TLH, total laparoscopic hysterectomy; USLS, uterosacral ligament suspension. Although limited by sample sizes, these reports further illustrate the feasibility of ICG-guided ureteral mapping in complex gynecologic surgery. 4.5 Implications for research and clinical practice Future studies should consider reporting common operative outcomes, including operative time, EBL, instillation duration, ureter identification time, and ureteral complications, in both mean ± standard deviation and median (IQR) formats to aid future evidence synthesis and evaluation of ICG efficacy and safety. Furthermore, prospective observational studies comparing ICG-assisted visualization with other visualization techniques or no assisted visualization are needed to better establish ICG's clinical impact. Continued investigation is warranted in high-risk populations, such as deep infiltrating endometriosis or previous pelvic surgery. Incorporation of ergonomics and surgical workload may help to clarify the broader benefits of ICG beyond anatomic visualization. Collectively, addressing these gaps will strengthen the evidence base and inform integration of ICG into routine gynecologic practice. 5 CONCLUSION Intraureteral ICG with NIRF imaging appears to be a feasible and safe adjunct for intraoperative ureteral visualization during gynecologic surgery, including in complex cases with distorted pelvic anatomy. Across available studies, ICG consistently enabled real-time ureter identification with no reported ureteral injuries or dye-related complications. However, the current evidence base is limited by small, predominantly retrospective observational studies with heterogeneous outcome reporting. Preliminary findings suggest potential benefits in operative safety, efficiency, and surgeon workload, but prospective observational studies with standardized outcome definitions are needed to better characterize the clinical impact of intraureteral ICG and to inform its role in routine gynecologic surgical practice. AUTHOR CONTRIBUTIONS VZ contributed to methodology, investigation, data curation, visualization, project administration, writing—original draft, writing—review and editing; designed and led the review, developed the search strategy, conducted level 1 and 2 screening and full-text review, performed ROBINS-I and GRADE assessments, extracted data for Tables 1 and 2 and Table S1, created Figures 1 and 2, and drafted, revised, and edited the manuscript. DM contributed to investigation, data curation, writing—original draft, writing—review and editing; and independently performed level 1 and 2 screening and ROBINS-I assessment, extracted data for Tables 3 and 4, and Table S2, and drafted, revised, and edited the manuscript. QY contributed to supervision, methodology, validation, resources, writing—review and editing; and provided oversight and methodologic guidance, adjudicated screening conflicts, validated study methods, and critically reviewed manuscript drafts for accuracy and interpretation. XG contributed to conceptualization, methodology, supervision; and initiated the study, contributed to study design and methodology, and provided critical review of the manuscript. All authors reviewed and approved the final version of the manuscript. ACKNOWLEDGMENTS The authors thank the Division of Minimally Invasive Gynecologic Surgery at Baylor College of Medicine, Houston, TX, USA, for their guidance and support throughout the development of this systematic review. FUNDING INFORMATION This project is investigator-initiated and not funded. CONFLICT OF INTEREST STATEMENT The authors have no conflicts of interest. DATA AVAILABILITY STATEMENT Data sharing is not applicable to this article as no new data were created or analyzed in this study.