Total laparoscopic hysterectomy (TLH) is a minimally invasive surgical procedure widely adopted for the removal of the uterus, offering benefits such as reduced recovery time, lower postoperative pain, and minimal scarring compared to open surgery. Despite its advantages, TLH carries risks, including ureteral injuries, vascular complications, and unintended damage to surrounding structures, which can lead to significant morbidity. To enhance the safety of TLH, indocyanine green (ICG) fluorescence imaging has emerged as a transformative intraoperative tool. By improving visualization of critical anatomical structures and tissue perfusion, ICG fluorescence imaging mitigates complications, enhances surgical precision, and improves patient outcomes.
 
The Role of ICG Fluorescence Imaging in Surgery
 
ICG is a near-infrared fluorescent dye that, when injected intravenously or directly into tissues, binds to plasma proteins and emits fluorescence when excited by specific wavelengths of light. This fluorescence is captured by specialized imaging systems, enabling real-time visualization of anatomical structures, blood flow, and tissue perfusion. In TLH, ICG is primarily used to delineate the ureters, assess vascular anatomy, and evaluate tissue viability, addressing some of the most common challenges faced during the procedure.
 
The integration of ICG fluorescence imaging into laparoscopic systems, such as those equipped with near-infrared cameras, has made it accessible and practical for gynecologic surgeons. Its safety profile is well-established, with a low incidence of adverse reactions, making it an ideal adjunct for intraoperative use. By providing dynamic, real-time feedback, ICG enhances the surgeon’s ability to navigate complex pelvic anatomy, particularly in cases complicated by adhesions, endometriosis, or malignancy.
 
Enhancing Ureteral Visualization
 
One of the most significant risks in TLH is ureteral injury, with reported incidence rates ranging from 0.5% to 2%. The ureters, located in close proximity to the uterus and cervix, are vulnerable during dissection and ligation of the uterine arteries. Failure to identify the ureters can result in laceration, crush injuries, or thermal damage, leading to complications such as urinomas, fistulas, or renal dysfunction.
 
ICG fluorescence imaging addresses this challenge through ureteral mapping. After intravenous or intraureteral administration of ICG, the dye is excreted into the urine, rendering the ureters fluorescent under near-infrared imaging. This allows surgeons to clearly distinguish the ureters from surrounding tissues, even in the presence of anatomical distortions. Studies have demonstrated that ICG-guided ureteral visualization significantly reduces the risk of injury, with some trials reporting a near-zero incidence of ureteral complications when ICG is employed. By providing a clear roadmap of the ureteral course, ICG empowers surgeons to perform dissections with greater confidence and precision.
 
Assessing Vascular Anatomy and Tissue Perfusion
 
In addition to ureteral protection, ICG fluorescence imaging enhances the safety of TLH by improving visualization of vascular structures and confirming tissue perfusion. During TLH, ligation of the uterine arteries is a critical step that requires precise identification to avoid bleeding or damage to adjacent vessels. ICG angiography, performed by injecting the dye intravenously, highlights blood flow in real time, enabling surgeons to confirm the location of major vessels, such as the uterine and internal iliac arteries, before proceeding with ligation.
 
Furthermore, ICG can assess tissue perfusion at the vaginal cuff, the site where the vagina is closed after hysterectomy. Adequate blood supply to this area is essential for proper healing and prevention of complications such as dehiscence or infection. By injecting ICG and observing fluorescence patterns, surgeons can verify that the vaginal cuff is well-perfused, reducing the risk of postoperative complications. This capability is particularly valuable in patients with compromised vascularity due to prior surgeries, radiation, or comorbidities.
 
Advantages Over Traditional Methods
 
Compared to traditional methods for enhancing safety in TLH, such as preoperative ureteral stenting or reliance on visual inspection alone, ICG fluorescence imaging offers several advantages. Preoperative stenting, while effective in some cases, is invasive, costly, and associated with risks such as infection or discomfort. In contrast, ICG is minimally invasive, requiring only a simple injection, and provides immediate, dynamic visualization without altering the surgical workflow.
 
Moreover, ICG overcomes the limitations of white-light laparoscopy, which relies heavily on the surgeon’s experience to differentiate tissues based on color and texture. In challenging cases—such as those involving obesity, dense adhesions, or abnormal anatomy—white-light imaging may be insufficient. ICG fluorescence imaging transcends these barriers by highlighting structures in a way that is independent of lighting conditions or tissue appearance, ensuring consistent results across diverse patient populations.
 
Challenges and Limitations
 
Despite its promise, the adoption of ICG fluorescence imaging in TLH is not without challenges. The technology requires investment in specialized laparoscopic equipment, which may be cost-prohibitive for some institutions, particularly in low-resource settings. Additionally, surgeons must undergo training to interpret fluorescence images accurately and integrate the technology into their practice. While ICG itself is inexpensive and widely available, the overall cost-effectiveness of the approach depends on reducing complication rates and hospital stays, which requires further long-term studies.
 
Another limitation is the potential for false negatives or positives in fluorescence imaging. For instance, ureteral visualization may be suboptimal in patients with impaired renal function, as ICG excretion depends on kidney clearance. Similarly, tissue perfusion assessments may be affected by factors such as dye timing or camera sensitivity. These limitations underscore the need for standardized protocols and ongoing research to optimize ICG use in TLH.
 
Future Directions
 
The success of ICG fluorescence imaging in TLH has sparked interest in its broader application within gynecologic surgery and beyond. Ongoing advancements in imaging technology, such as higher-resolution cameras and augmented reality overlays, promise to further enhance the precision of ICG-guided procedures. Additionally, the development of targeted fluorescent agents that bind to specific tissues or pathologies could expand the utility of fluorescence imaging, enabling personalized approaches to surgery.
 
Clinical trials are also needed to establish definitive evidence of ICG’s impact on patient outcomes. While early studies are promising, large-scale, randomized controlled trials comparing ICG-guided TLH to standard techniques will help quantify reductions in complications, operative time, and healthcare costs. Such data will be critical for securing reimbursement from payers and encouraging widespread adoption.
 
Conclusion
 
ICG fluorescence imaging represents a significant advancement in improving the safety of total laparoscopic hysterectomy. By enhancing visualization of the ureters, vascular structures, and tissue perfusion, ICG mitigates some of the most serious risks associated with the procedure, including ureteral injuries and postoperative complications. Its real-time, non-invasive nature makes it a practical and powerful tool for surgeons, particularly in complex cases. While challenges such as cost and training remain, the potential of ICG to transform TLH is undeniable. As technology evolves and evidence accumulates, ICG fluorescence imaging is poised to become a standard of care, ensuring safer, more effective outcomes for patients undergoing laparoscopic hysterectomy.