Application of indocyanine green (ICG)-guided surgery in clinical practice: lesson to learn from other organs-an overview on clinical applications and future perspectives

SYL3C Aptamer-DNA Tetrahedra Conjugates Enable Near-Infrared Fluorescent Imaging of Colorectal Cancer

Purpose

SYL3C is an optimized DNA aptamer with high selectivity and affinity for the epithelial cell adhesion molecule (EpCAM), an overexpressed tumor antigen in colorectal cancer (CRC). While its cellular affinity has been validated, in vivo studies are lacking.

Methods

This study modifies SYL3C with the fluorescent motif Cy7 to evaluate its metabolism and diagnostic potential in EpCAM-positive HT-29 xenograft mice using near-infrared fluorescence (NIRF). We also employ DNA Tetrahedra (DTN) to load the Cy7-DTN-SYL3C probe and assess whether this strategy improves circulation and tumor uptake of SYL3C.

Results

Cy7-SYL3C is primarily metabolized by the kidneys and enables targeted imaging of HT-29 tumors, outperforming untargeted Cy7-DTN. The DTN coupling strategy prolongs SYL3C metabolism and enhances tumor probe uptake about twice higher than Cy7-SYL3C over 24 hours.

Conclusion

This study presents preliminary evidence for the SYL3C aptamer's potential in vivo imaging of EpCAM-positive CRC. The DTN conjugation strategy may extend the aptamer's metabolic stability and improve tumor uptake, expanding its applications in CRC diagnosis and treatment.

Size-Controlled Self-Assembly for Bimodal In Vivo Imaging

Contrast agents (CAs) are essential in biomedical imaging to aid in the diagnosis and therapy monitoring of disease. However, they are typically restricted to one imaging modality and have fixed properties such as size, shape, toxicity profile, or photophysical characteristics, which hampers a comprehensive view of biological processes. Herein, rationally designed dye assemblies are introduced as a unique CA platform for simultaneous multimodal and multiscale biomedical imaging. To this end, a series of amphiphilic aza-BODIPY dyes are synthesized with varying hydrophobic domains (C1, C8, C12, and C16) that self-assemble in aqueous media into nanostructures of tunable size (50 nm-1 µm) and photophysical properties. While C1 exhibits oblique-type exciton coupling and negligible emission, C8-C16 bearing longer alkyl chains undergo J-type aggregation with NIR absorption and emission and excellent photoacoustic properties. Given these advantageous features, aza-BODIPY specific, semi-quantitative fluorescence reflectance and photoacoustic imaging both in vitro and in vivo are established. Additionally, in vitro cell viability as well as murine in vivo biodistribution analysis with ex vivo validation showed excellent biocompatibility and a size-dependent biodistribution of nanostructures to different organ beds. These results broaden the scope of aqueous self-assembly to multimodal imaging and highlight its great potential for rationalizing numerous biomedical questions.

Real-Time Navigation in Liver Surgery Through Indocyanine Green Fluorescence: An Updated Analysis of Worldwide Protocols and Applications

BACKGROUND

Indocyanine green (ICG) fluorescence has seen extensive application across medical and surgical fields, praised for its real-time navigation capabilities and low toxicity. Initially employed to assess liver function, ICG fluorescence is now integral to liver surgery, aiding in tumor detection, liver segmentation, and the visualization of bile leaks. This study reviews current protocols and ICG fluorescence applications in liver surgery, with a focus on optimizing timing and dosage based on clinical indications.

METHODS

Following PRISMA guidelines, we systematically reviewed the literature up to 27 January 2024, using PubMed and Medline to identify studies on ICG fluorescence used in liver surgery. A systematic review was performed to evaluate dosage and timing protocols for ICG administration.

RESULTS

Of 1093 initial articles, 140 studies, covering a total of 3739 patients, were included. The studies primarily addressed tumor detection (40%), liver segmentation (34.6%), and both (21.4%). The most common ICG fluorescence dose for tumor detection was 0.5 mg/kg, with administration occurring from days to weeks pre-surgery. Various near-infrared (NIR) camera systems were utilized, with the PINPOINT system most frequently cited. Tumor detection rates averaged 87.4%, with a 10.5% false-positive rate. Additional applications include the detection of bile leaks, lymph nodes, and vascular and biliary structures.

CONCLUSIONS

ICG fluorescence imaging has emerged as a valuable tool in liver surgery, enhancing real-time navigation and improving clinical outcomes. Standardizing protocols could further enhance ICG fluorescence efficacy and reliability, benefitting patient care in hepatic surgeries.

Indocyanine green fluorescence-guided surgery in the emergency setting: the WSES international consensus position paper

BACKGROUND

Decision-making in emergency settings is inherently complex, requiring surgeons to rapidly evaluate various clinical, diagnostic, and environmental factors. The primary objective is to assess a patient's risk for adverse outcomes while balancing diagnoses, management strategies, and available resources. Recently, indocyanine green (ICG) fluorescence imaging has emerged as a valuable tool to enhance surgical vision, demonstrating proven benefits in elective surgeries.

AIM

This consensus paper provides evidence-based and expert opinion-based recommendations for the standardized use of ICG fluorescence imaging in emergency settings.

METHODS

Using the PICO framework, the consensus coordinator identified key research areas, topics, and questions regarding the implementation of ICG fluorescence-guided surgery in emergencies. A systematic literature review was conducted, and evidence was evaluated using the GRADE criteria. A panel of expert surgeons reviewed and refined statements and recommendations through a Delphi consensus process, culminating in final approval.

RESULTS

ICG fluorescence imaging, including angiography and cholangiography, improves intraoperative decision-making in emergency surgeries, potentially reducing procedure duration, complications, and hospital stays. Optimal use requires careful consideration of dosage and timing due to limited tissue penetration (5-10 mm) and variable performance in patients with significant inflammation, scarring, or obesity. ICG is contraindicated in patients with known allergies to iodine or iodine-based contrast agents. Successful implementation depends on appropriate training, availability of equipment, and careful patient selection.

CONCLUSIONS

Advanced technologies and intraoperative navigation techniques, such as ICG fluorescence-guided surgery, should be prioritized in emergency surgery to improve outcomes. This technology exemplifies precision surgery by enhancing minimally invasive approaches and providing superior real-time evaluation of bowel viability and biliary structures-areas traditionally reliant on the surgeon's visual assessment. Its adoption in emergency settings requires proper training, equipment availability, and standardized protocols. Further research is needed to evaluate cost-effectiveness and expand its applications in urgent surgical procedures.

Real-Time Fluorescence Imaging for Thoracic Duct Identification during Oesophagectomy: A Systematic Review of the Literature

Postoperative chylothorax is a serious complication after oesophagectomy. Real-time identification of the thoracic duct (TD) could prevent injury or facilitate prompt management when it occurs. Intraoperative TD lymphography with indocyanine green (ICG) is a novel technique that may help prevent chyle leaks following thoracic surgery. A systematic search of PubMed, Embase, MEDLINE, Scopus, and the Cochrane Library for studies published until July 2024 evaluating ICG for TD identification during oesophagectomy was performed. Studies were included in the review if they assessed intraoperative TD identification with ICG to prevent chyle leakage in patients undergoing oesophagectomy. Nine of 265 screened papers were included in the present review, with 3 reporting comparative techniques of TD identification between patients. Only 1 study had a control group without ICG administration. TD was identified in 281 of the 303 patients who received ICG. Chyle leak incidence was 0.66% in the ICG group. The mean observation time of TD after ICG administration was 162 minutes. Most of the included patients received neoadjuvant treatment before surgery. Different application routes of ICG have been reported, with the most prominent one being through the inguinal region under ultrasound guidance. Real- time TD identification with ICG might be a valuable tool for avoiding injury or managing it intraoperatively. To our knowledge, this is the first systematic review on this complex topic. However, as no randomized controlled trials have been published, sufficient evidence is needed to determine whether the aforementioned method can sufficiently reduce the chyle leak rate.

Intraoperative fluorescence redefining neurosurgical precision

Surgical resection is essential for treating solid tumors, with success largely dependent on the complete excision of neoplastic cells. However, neurosurgical procedures must delicately balance tumor removal with the preservation of surrounding tissue. Achieving clear margins is particularly challenging in cases like glioblastoma due to the limitations of traditional white light visualization. These limitations often result in incomplete resections, leading to frequent recurrences, or excessive resection that harms vital neural structures, causing iatrogenic nerve damage, which can lead to sensory and functional deficits. Current statistics reveal a 90% recurrence rate for malignant gliomas. Similarly, an 8% incidence of iatrogenic nerve trauma contributes to an estimated 25 million cases of peripheral nerve injury globally each year. These figures underscore the urgent need for improved intraoperative techniques for lesion margin and nerve identification and visualization. Recent advances in neurosurgical imaging, such as fluorescence-guided surgery (FGS), have begun to address these challenges. Fluorescent agents used in FGS illuminate target tissues, although not all do so selectively. Despite the promising results of agents such as 5-aminolevulinic acid and indocyanine green, their applications are mainly limited by issues of sensitivity and specificity. Furthermore, these agents do not effectively address the need for precise nerve visualization. Nerve Peptide 41, a novel systemically administered fluorescent nerve-targeted probe, shows promise in filling this gap. This review assesses the major fluorescent imaging modalities in neurosurgery, highlighting each of their benefits, limitations, and potential.

Application of Indocyanine Green Fluorescence Imaging During Laparoscopic Reoperations of the Biliary Tract Enhances Surgical Precision and Efficiency

BACKGROUND

A history of abdominal surgery is considered a contraindication for laparoscopic procedures. However, the advancements in laparoscopic instruments and techniques have facilitated the performance of increasingly intricate operations, even in patients with prior abdominal surgeries. ICG fluorescence imaging technology offers advantages in terms of convenient operation and clearer intraoperative bile duct imaging, as confirmed by numerous international clinical studies on its feasibility and safety. The application of ICG fluorescence imaging technology in repeat laparoscopic biliary surgery, however, lacks sufficient reports.

METHODS

The clinical data of patients who underwent elective reoperation of the biliary tract in our department between January 2020 and June 2022 were retrospectively analyzed. ICG was injected peripherally before the operation, and near-infrared light was used for 3-dimensional imaging of the bile duct during the operation.

RESULTS

Altogether, 143 patients were included in this study and divided into the fluorescence and nonfluorescence groups according to the inclusion criteria. Among the 26 patients in the fluorescence group, cholangiography was successfully performed in 24 cases, and the success rate of intraoperative biliary ICG fluorescence imaging was 92.31%. The intraoperative biliary tract identification time was significantly different between the fluorescence and nonfluorescence groups, but no statistical difference was observed in the final operation method, operative time, and intraoperative blood loss between the 2 groups. Although there was no significant difference in the postoperative ventilation rate, incidence of bile leakage, and stone recurrence rate at 6 months postoperatively between the 2 groups ( P >0.05), a significant difference in postoperative hospitalization days was observed ( P =0.032).

CONCLUSION

The application of ICG fluorescence imaging technology in laparoscopic reoperation of the biliary tract is useful for the early identification of the biliary tract during operation, thereby shortening the operative time and reducing the risk of damage to nonoperative areas. This approach also enhances the visualization of the biliary system and avoids secondary injury intraoperatively due to poor identification of the biliary system. This technique is safe for repeat biliary tract surgery and has a good application prospect.

Multifunctional nanoparticles potentiate in-situ tumor vaccines via reversing insufficient Photothermal therapy by disrupting tumor vasculature

Photothermal therapy can trigger immunogenic cell death and release personalized in-situ tumor vaccine, activating immune responses to eliminate systemic tumors beyond the irradiated zone. However, the immune response of the in-situ tumor vaccines is often undermined by the residual tumor cells and their induced immunosuppressive tumor microenvironment (TME), which is attributed to insufficient photothermal effects stemming from the limited accumulation of photosensitizers. To overcome these limitations, we developed multi-functional nanoparticles (VI@Gd-NPs) that integrate a tumor vasculature-specific disrupting agent (Vadimezan, Phase III clinical drug), a photosensitizer (Indocyanine Green, ICG), and a magnetic resonance imaging contrast agent (Gadolinium, Gd) through chemical self-assembly. By selectively disrupting the tumor vasculature, these nanoparticles enhance the intratumoral delivery of photosensitizers (ICG and blood cells), and Gd. With the guidance of Gd-enhanced MRI, the improved delivery facilitates comprehensive photothermal ablation and regulates the TME, further initiating the in-situ tumor vaccine. Notably, this approach significantly enhances anti-tumor immune responses, improves survival rates, and reduces tumor recurrence and metastasis in various animal models. Moreover, depleting CD8+ T cells reverses these therapeutic benefits, highlighting the critical role of adaptive T cell immunity. Therefore, the VI@Gd-NPs treatment holds great potential for reigniting the in-situ tumor vaccine of photothermal therapy.

Botulinum Toxin for the Treatment of Raynaud's Conditions of the Hand: Clinical Practice Updates and Future Directions

Raynaud's conditions of the hand, referred to commonly as Raynaud's phenomenon, both primary and secondary, represents a spectrum of disorders affecting the digits, characterised by recurrent episodes of vasospasm that result in a triad of symptoms: pain, pallor, and cyanosis. Various therapies, ranging from conservative hand therapy techniques to surgical sympathectomy, have been explored with inconsistent results. Recently, the local administration of botulinum toxin type-A (BTX-A) has re-emerged as a treatment option for this condition. This review delves into the mechanistic pathways of BTX-A therapy, optimal dosing concentrations, administration techniques, and its safety profile. A critical analysis of published studies to date demonstrates varied clinical efficacy of BTX-A in Raynaud's conditions based on patient-reported outcome measures and objective measures of outcomes assessment. Thus, in order to accurately assess the clinical effectiveness of BTX-A in future robust studies, this review emphasises the importance of streamlining patient selection to minimise heterogeneity in disease severity, optimising recruitment to ensure adequate statistical power, and establishing sensitive outcome measures to monitor response and discern treatment efficacy. Additionally, addressing concerns such as minimising antibody resistance, extending the duration of treatment effects on tissues, and exploring new modalities to assess hand perfusion will be focal points for future research and BTX-A drug development.

Knowledge, attitudes and practices of using Indocyanine Green (ICG) fluorescence in emergency surgery: an international web-based survey in the ARtificial Intelligence in Emergency and trauma Surgery (ARIES)-WSES project

Fluorescence imaging is a real-time intraoperative navigation modality to enhance surgical vision and it can guide emergency surgeons while performing difficult, high-risk surgical procedures. The aim of this study is to assess current knowledge, attitudes, and practices of emergency surgeons in the use of indocyanine green (ICG) in emergency settings. Between March 08, 2023 and April 10, 2023, a questionnaire composed of 27 multiple choice and open-ended questions was sent to 200 emergency surgeons who had previously joined the ARtificial Intelligence in Emergency and trauma Surgery (ARIES) project promoted by the WSES. The questionnaire was developed by an emergency surgeon with an interest in advanced technologies and artificial intelligence. The response rate was 96% (192/200). Responders affirmed that ICG fluorescence can support the performance of difficult surgical procedures in the emergency setting, particularly in the presence of severe inflammation and in evaluating bowel viability. Nevertheless, there were concerns regarding accessibility and availability of fluorescence imaging in emergency settings. Eighty-seven out of 192 (45.3%) respondents have a fluorescence imaging system of vision for both elective and emergency surgical procedures; 32.3% of respondents have this system solely for elective procedures; 21.4% of respondents do not have this system, 15% do not have experience with it, and 38% do not use this imaging in emergency surgery. Less than 1% (2/192) affirmed that ICG fluorescence changed always their intraoperative decision-making. Precision surgery effectively tailors surgical interventions to individual patient characteristics using advanced technology, data analysis and artificial intelligence. ICG fluorescence can serve as a valid and safe tool to guide emergency surgery in different scenarios, such as intestinal ischemia and severe acute cholecystitis. Due to the lack of high-level evidence within this field, a consensus of expert emergency surgeons is needed to encourage stakeholders to increase the availability of fluorescence imaging systems and to support emergency surgeons in implementing ICG fluorescence in their daily practice.

Neuroprotective effects of anti-TRAIL-ICG nanoagent and its multimodal imaging evaluation in cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion injury (CIRI) is a major challenge to neuronal survival in acute ischemic stroke (AIS). However, effective neuroprotective agents remain to be developed for the treatment of CIRI. In this work, we have developed an Anti-TRAIL protein-modified and indocyanine green (ICG)-responsive nanoagent (Anti-TRAIL-ICG) to target ischemic areas and then reduce CIRI and rescue the ischemic penumbra. In vitro and in vivo experiments have demonstrated that the carrier-free nanoagent can enhance drug transport across the blood-brain barrier (BBB) in stroke mice, exhibiting high targeting ability and good biocompatibility. Anti-TRAIL-ICG nanoagent played a better neuroprotective role by reducing apoptosis and ferroptosis, and significantly improved ischemia-reperfusion injury. Moreover, the multimodal imaging platform enables the dynamic in vivo examination of multiple morphofunctional information, so that the dynamic molecular events of nanoagent can be detected continuously and in real time for early treatment in transient middle cerebral artery occlusion (tMCAO) models. Furthermore, it has been found that Anti-TRAIL-ICG has great potential in the functional reconstruction of neurovascular networks through optical coherence tomography angiography (OCTA). Taken together, our work effectively alleviates CIRI after stoke by blocking multiple cell death pathways, which offers an innovative strategy for harnessing the apoptosis and ferroptosis against CIRI.

A preliminary investigation of precise visualization, localization, and resection of pelvic lymph nodes in bladder cancer by using indocyanine green fluorescence-guided approach through intracutaneous dye injection into the lower limbs and perineum

Objective

This study aimed to investigate the feasibility and effectiveness of using indocyanine green (ICG) injected intracutaneously through the lower limbs and perineum for visualized tracking, localization, and qualitative assessment of pelvic lymph nodes (LNs) in bladder cancer to achieve their accurate resection.

Methods

First, ICG was injected into the LN metastasis model mice lower limbs, and real-time and dynamic in vivo and ex vivo imaging was conducted by using a near-infrared fluorescence imaging system. Additionally, 26 patients with bladder cancer were enrolled and divided into intracutaneous group and transurethral group. A near-infrared fluorescence imaging device with internal and external imaging probes was used to perform real-time tracking, localization, and resection of the pelvic LNs.

Results

The mice normal LNs and the metastatic LNs exhibited fluorescence. The metastatic LNs showed a significantly higher signal-to-background ratio than the normal LNs (3.9 ± 0.2 vs. 2.0 ± 0.1, p < 0.05). In the intracutaneous group, the accuracy rate of fluorescent-labeled LNs was 97.6%, with an average of 11.3 ± 2.4 LNs resected per patient. Six positive LNs were detected in three patients (18.8%). In the transurethral group, the accuracy rate of fluorescent-labeled LNs was 84.4%, with an average of 8.6 ± 2.3 LNs resected per patient. Two positive LNs were detected in one patient (12.5%).

Conclusion

Following the intracutaneous injection of ICG into the lower limbs and perineum, the dye accumulates in pelvic LNs through lymphatic reflux. By using near-infrared fluorescence laparoscopic fusion imaging, physicians can perform real-time tracking, localization, and precise resection of pelvic LNs.

Don't forget emergency surgery! Lessons to learn from elective indocyanine green-guided gastrointestinal interventions

Fluorescence-based imaging has found application in several fields of elective surgery, but there is still a lack of evidence in the literature about its use in the emergency setting. Clinical trials have consistently shown that indocyanine green (ICG)-guided surgery can dramatically reduce the risk of postoperative complications, length of in-hospital stay and total healthcare costs in the elective setting. It is well-known that emergency surgery has a higher complication rate than its elective counterpart, therefore an impelling need for research studies to explore, validate and develop this issue has been highlighted. The present editorial aims to provide a critical overview of currently available applications and pitfalls of ICG fluorescence in abdominal emergencies. Furthermore, we evidenced how the experience of ICG-fluorescence in elective surgery might be of great help in implementing its use in acute situations. In the first paragraph we analyzed the tips and tricks of ICG-guided cancer surgery that might be exploited in acute cases. We then deepened the two most described topics in ICG-guided emergency surgery: Acute cholecystitis and intestinal ischemia, focusing on both the advantages and limitations of green-fluorescence application in these two fields. In emergency situations, ICG fluorescence demonstrates a promising role in preventing undue intestinal resections or their entity, facilitating the detection of intestinal ischemic zones, identifying biliary tree anatomy, reducing post-operative complications, and mitigating high mortality rates. The need to improve its application still exists, therefore we strongly believe that the elective and routinary use of the dye is the best way to acquire the necessary skills for emergency procedures.

Robotic versus open resection for colorectal liver metastases in a "referral centre Hub&Spoke learning program". A multicenter propensity score matching analysis of perioperative outcomes

Background

Surgical resection is still considered the optimal treatment for colorectal liver metastasis (CRLM). Although laparoscopic and robotic surgery demonstrated their reliability especially in referral centers, the comparison between perioperative outcomes of robotic liver resection (RLR) and open (OLR) liver resection are still debated when performed in referral centers for robotic surgery, not dedicated to HPB. Our study aimed to verify the efficacy and safety of perioperative outcomes after RLR and OLR for CRLM in an HUB&Spoke learning program (H&S) between a high volume center for liver surgery and high volume center for robotic surgery.

Methods

We analyzed prospective databases of Pineta Grande Hospital (Castel Volturno) and Robotic Surgical Units (Foligno-Spoleto and Arezzo) from 2011 to 2021. A 1:1 propensity score matching (PSM) was performed according to baseline characteristics of patients, solitary/multiple CRLM, anterolateral/posterosuperior location.

Results

383 patients accepted to be part of the study (268 ORL and 115 RLR). After PSM, 45 patients from each group were included. Conversion rate was 8.89 %. RLR group had a significantly lower blood loss (226 vs. 321 ml; p=0.0001), and fewer major complications (13.33 % vs. 17.78 %; p=0.7722). R0 resection was obtained in 100% of OLR (vs.95.55%, p =0.4944. Hospital stay was 8.8 days in RLR (vs. 15; p=0.0001).Conclusion: H&S represents a safe and effective program to train general surgeons also in Hepatobiliary surgery providing R0 resection rate, blood loss volume and morbidity rate superimposable to referral centers. Furthermore, H&S allow a reduction of health mobility with consequent money saving for patients and institutions.

Optimizing Indocyanine Green Dosage for Near-Infrared Fluorescence Perfusion Assessment in Bowel Anastomosis: A Prospective, Systematic Dose-Ranging Study

BACKGROUND

Indocyanine green (ICG) near-infrared fluorescence (NIRF) has emerged as a promising technique for visualizing tissue perfusion. However, within the wide range of dosages and imaging conditions currently being applied, the optimal dosage of ICG remains unclear. This study aimed to investigate the feasibility and implications of implementing lower dosages of ICG than commonly used for visual and quantitative perfusion assessment in a standardized setting.

METHODS

A prospective single-center cohort study was conducted on patients undergoing ileostomy reversal by hand-sewn anastomosis. ICG-NIRF visualization was performed before (T1) and after (T2) anastomosis with one of four different dosages of ICG (5 mg, 2.5 mg, 1.25 mg, or 0.625 mg) and recorded. Postoperatively, each visualization was evaluated for signal strength, completeness, and homogeneity of fluorescence. Additionally, perfusion graphs were generated by a software-based quantitative perfusion assessment, allowing an analysis of perfusion parameters. Statistical analysis comparing the effect of the investigated dosages on these parameters was performed.

RESULTS

In total, 40 patients were investigated. Visual evaluation demonstrated strong, complete, and homogeneous fluorescence signals across all dosages. Perfusion graph assessment revealed a consistent shape for all dosages (ingress followed by egress phase). While the average signal intensity decreased with dosage, it was sufficient to enable perfusion assessment even at the lowest dosages of 1.25 mg and 0.625 mg of ICG. The baseline intensity at T2 (the second intraoperative visualization) significantly decreased with dosage. The slope of the egress phase steepened with decreasing dosage.

CONCLUSIONS

Lower dosages of ICG were sufficient for intraoperative perfusion assessment, while causing lower residual fluorescence and quicker egress in subsequent visualizations.

Performance of indocyanine green in sentinel lymph node mapping and lymph node metastasis in penile cancer: systematic review, meta-analysis, and single-center experience

PURPOSE

The aim of this study was to investigate the overall sensitivity and specificity of indocyanine green (ICG)-near-infrared (NIR) fluorescence imaging in the detection of sentinel lymph node metastasis (SLNM) in penile cancer.

METHODS

We searched PubMed, Embase, Web of Science, Scopus, and the Cochrane Library databases to identify manuscripts where ICG was intravenously administered prior to or during penile cancer surgery, with no restriction on language or publication status. The results extracted are presented as forest plots.

RESULTS

Seven studies were included in the analysis. The median sensitivity and specificity of ICG-NIR imaging for SLNM detection were 100 and 4%, respectively; the pooled sensitivity was 100.0% (95% confidence interval [CI] 97.0-100.0) and specificity was 2.0% (95% CI 1.0-3.0). There was no significant difference in the diagnostic results between different injection sites and doses in each experimental group.

CONCLUSION

To our knowledge, this meta-analysis is the first to summarize the diagnostic performance of ICG-NIR imaging for SLNM detection in penile cancer. ICG is sensitive in the imaging of SLN tissue, which can consequently improve the accuracy of lymph node detection. However, the specificity is very low.

New clinical application of indocyanine green in fluorescence-guided laparoscopic lymph-node biopsy in case of lymphoma. Preliminary results on a case series

BACKGROUND

Indocyanine Green (ICG) fluorescence-guided surgery is widely used for intraoperative visualization of lymphatic structures. To date, there are no reports indicating this dye being used in lymph node biopsies for suspected or relapsed lymphoma.

METHODS

Between October 2021 and June 2022, 12 patients underwent a fluorescence-guided laparoscopic lymph node biopsy (FGLLB) using ICG. The following was retrospectively evaluated: the dosage of ICG, the injection site, the number of patients where fluorescence was obtained after ICG administration, and additionally, the parameters indicating the outcome of the surgical procedure.

RESULTS

The median duration of the surgery was 90 min. A laparotomy conversion was required in one case due to bleeding. Fluorescence was obtained in 10/12 (83.3%) patients by means of subcutaneous/perilesional injection in six of the patients, and intravenously in the other four. Hospitalization had a mean duration of three days. There were no major postoperative complications. FGLLB was used in seven patients to follow lymphoproliferative disease progression, and in five patients to establish a diagnosis. In all cases, FGLLB provided the information necessary for the correct diagnosis.

CONCLUSIONS

Fluorescence with ICG offers a simple and safe method for detecting pathological lymph nodes. FGLLB in suspected intra-abdominal lymphoma can largely benefit from this new opportunity which has not yet been tested to date. Further studies with large case series are needed to confirm its efficacy.

Preoperative tumor marking with indocyanine green (ICG) prior to minimally invasive colorectal cancer: a systematic review of current literature

Aim

To describe the currently available evidence regarding the efficacy and safety of preoperative tumor marking using indocyanine green (ICG) prior to laparoscopic or robotic colorectal resections.

Methods

A systematic search for relevant studies was conducted using the following databases: Embase (OVID), MEDLINE® (OVID), APA PsycInfo (OVID), Global Health (OVID) and HMIC Health Management Information Consortium (OVID) through June 2022 reported according to PRISMA 2020 guidelines. Primary outcome was the detection rate of the tumor sites preoperatively marked with ICG. Secondary outcomes were timing of ICG injection in days prior to the operation and technique-related complications.

Results

Eight single center studies, published between 2008 and 2022, were identified yielding a total of 1,061 patients, of whom 696 were preoperatively tattooed with ICG. Injection dosage of diluted ICG ranged from 0.1-1.5 ml. Four studies used the saline test injection method prior to ICG injection. When the marking was placed within one week, the visualization rate was 650/668 (97%), whereas when it was longer than one week, the detection rate was 8/56 (14%). No severe complications were reported.

Conclusion

Preoperative tumor marking using ICG prior to minimally invasive colorectal resections is safe and effective, allowing intraoperative tumor site location when performed up to a week prior to surgery without disturbing the surgical view in potential mild complications.

A Hypothetical New Challenging Use for Indocyanine Green Fluorescence during Laparoscopic Appendectomy: A Mini-Series of Our Experience and Literary Review

Laparoscopic appendectomy (LA) is a well-standardized surgical procedure, but there are still controversies about the different devices to be used for the appendiceal stump closure and the related postoperative complications. Indocyanine green (ICG) fluorescence angiography (FA) has already been shown to be helpful in elective and emergency surgery, providing intraoperative information on tissue and organ perfusion, thus guiding the surgical decisions and the technical strategies. According to these two aspects, we report a mini-series of the first five patients affected by gangrenous and flegmonous acute appendicitis intraoperatively evaluated with ICG-FA during LA. The patients were admitted to the Emergency Department with an usual range of symptoms for acute appendicitis. The patients were successfully managed by fully LA with the help of a new hypothetical challenging use of ICG-FA.

Indocyanine Green-Loaded Nanobubbles Targeting Carbonic Anhydrase IX for Multimodal Imaging of Renal Cell Carcinoma

Background and Purpose

The early diagnosis and differential diagnosis of renal cell carcinoma (RCC) has always been a clinical difficulty and a research focus. Carbonic anhydrase IX (CA IX) is highly expressed on the cell membrane of RCC but is not expressed in normal renal tissues. In this study, nanobubbles (NBs) targeting CA IX with ultrasound and photoacoustic multimodal imaging capabilities were prepared to explore a new method for the diagnosis and differential diagnosis of RCC.

Methods

Indocyanine green (ICG)-loaded lipid NBs (ICG-NBs) were prepared by using the filming rehydration method, and anti-CA IX polypeptides (ACPs) were attached to their surfaces to prepare CA IX-targeted NBs (ACP/ICG-NBs). The particle size, zeta potential and ICG encapsulation efficiency of these nanobubbles were measured, and their specific targeting and binding abilities to RCC cells were determined. The in vitro and in vivo ultrasound, photoacoustic and fluorescence imaging characteristics of these nanobubbles were also assessed.

Results

The particle size of the ACP/ICG-NBs was 475.9 nm in diameter, and their zeta potential was -2.65 mV. Laser confocal microscopy and flow cytometry both confirmed that ACP/ICG-NBs had specific binding activity and ideal affinity to CA IX-positive RCC cells (786-O) but not to CA IX-negative RCC cells (ACHN). The intensities of the in vitro ultrasound, photoacoustic and fluorescence imaging were positively correlated with the concentrations of ACP/ICG-NBs. In in vivo ultrasound and photoacoustic imaging experiments, ACP/ICG-NBs exhibited specific enhanced ultrasound and photoacoustic imaging effects in 786-O xenograft tumors.

Conclusion

The ICG- and ACP-loaded targeted nanobubbles that we prepared had the capability of ultrasound, photoacoustic and fluorescence multimodal imaging and could specifically enhance the ultrasound and photoacoustic imaging of RCC xenograft tumors. This outcome has potential clinical application value for the diagnosis of RCC at the early stage and the differential diagnosis of benign and malignant kidney tumors.