Indocyanine green fluorescence imaging in colorectal surgery: overview, applications, and future directions

A mitochondria-interfering nanocomplex cooperates with photodynamic therapy to boost antitumor immunity

Immunotherapeutics against triple-negative breast cancer (TNBC) hold great promise. In this work, we provide a combination therapy for simultaneous increasing tumor immunogenicity and down-regulating programmed cell death ligand 1 (PD-L1) to boost antitumor immunity in TNBC. We prepare bis (diethyldithiocarbamate)-copper/indocyanine green nanoparticles (CuET/ICG NPs) simply in aqueous with one-pot method. CuET/ICG NPs interfere mitochondria, reduce oxygen consumption, and alleviate tumor hypoxia to potentiate photodynamic therapy (PDT) for amplifying immunogenic cell death (ICD). Meanwhile, mitochondria dysfunction leads to energy stress and activates AMPK pathway. As a result, CuET/ICG NPs downregulates membrane PD-L1 (mPD-L1) on both 4T1 cancer cells and cancer stem cells (CSCs) through AMP-activated protein kinase (AMPK)-mediated pathway in hypoxia. Cooperatively, the combinational therapy activates antitumor immunity and triggers long lasting immune memory response to resist tumor re-challenge. Our study represents an attempt that conquers tumor immunosuppressive microenvironment with simple biomedical materials and multimodality treatments.

A new EGFR and c-Met bispecific NIR-II fluorescent probe for visualising colorectal cancer and metastatic lymph nodes

BACKGROUND

The aim of the study was to increase the specificity and targeting of tumour imaging, targeting molecules that enable the simultaneous recognition and binding of multiple tumour-associated receptors. We constructed a NIR-II fluorescence probe based on a bispecific antibody to epidermal growth factor receptor (EGFR) and cellular mesenchymal-epithelial transition factor (c-Met) for visualising colorectal cancers (CRCs) and metastatic lymph nodes.

METHODS

The expression of EGFR and c-Met in tumour and metastatic lymph node specimens from patients with CRC was examined using immunohistochemistry. The EGFR and c-Met bispecific antibody (Rybrevant) was labelled, and its cell-specific binding ability was assessed using laser confocal microscopy. Subcutaneous CRC and orthotopic tumour models were constructed to evaluate the fluorescence imaging of the probe in vivo. To assess the performance of Rybrevant-IRDye800CW in the differential diagnosis of metastatic lymph nodes, a CRC lymph node metastasis model was constructed using human CRC cells implanted in mouse claw pads. Finally, surgically resected CRC tumours and lymph node specimens were incubated with Rybrevant-IRDye800CW for fluorescence NIR-II imaging to evaluate the efficacy of Rybrevant-IRDye800CW for preclinical visualisation.

FINDINGS

The combined expression rate of EGFR and c-Met in CRC and metastatic lymph nodes was significantly higher than the single-target expression rate. The bispecific probe Rybrevant-IRDye800CW was successfully synthesised, and its fluorescence signal could be extended up to 1600 nm using NIR-II imaging. Cell incubation experiments showed that the fluorescence intensity of Rybrevant-IRDye800CW was strongly correlated with EGFR and c-Met overexpression of the cells. NIR-II in vivo fluorescence imaging showed that double-positively expressing subcutaneous tumours significantly uptook Rybrevant-IRDye800CW after tail vein injection of the probe, which rapidly accumulated within the tumours in about 6 h. In EGFR and or c-Met blockade assays, subcutaneous tumours showed weaker uptake of Rybrevant-IRDye800CW. Similarly, Rybrevant-IRDye800CW was specifically identified in orthotopic CRC and lymph node metastasis models, with all orthotopic tumours showing high tumour-to-background ratios in NIR-II imaging. In a NIR-II preclinical study, Rybrevant-IRDye800CW could specifically identify fresh human CRC and its metastatic lymph node tissue.

INTERPRETATION

This study confirmed the complementary EGFR and c-Met expression in CRC and its metastatic lymph nodes. Compared to single-target probes, EGFR and c-Met dual-specific fluorescent probes identified CRC and its metastatic lymph nodes using NIR-II imaging. Thus, NIR-II-guided R0 surgery was performed to resect the CRC and metastatic lymph nodes.

FUNDINGS

This study was supported by the Beijing Natural Science Foundation (Grant numbers: L222054, 7244517, 4232058, L248026, L232020), National Natural Science Foundation of China (NSFC) (92059207, 92359301, 92259303, 62027901, 81930053, 81227901, U21A20386), CAS Youth Interdisciplinary Team (JCTD-2021-08), and the Fundamental Research Funds for the Central Universities (Grant no. JK2024-2-35-02).

Bismuth-Loaded Poly(α-amino acid) Nanoparticles for CT and Fluorescence Bimodal Imaging

X-ray computed tomography (CT) offers high spatial resolution and deep tissue penetration, but its low sensitivity limits early disease diagnosis. In contrast, fluorescence imaging (FI) provides high sensitivity, suffering from poor spatial resolution and limited tissue penetration. Combining CT and FI creates a complementary imaging method. Herein, we report bismuth-loaded poly(α-amino acid) nanoparticles (abbreviated as Bi NPs including Bi@POS, Bi@POS-FITC, and Bi@POS-ICG) for CT and fluorescence bimodal imaging. Bi NPs exhibit superior X-ray attenuation and fluorescence emission properties by integrating bismuth complexes with fluorescent dyes, including fluorescein isothiocyanate (FITC) and indocyanine green (ICG). The catechol moieties in poly(α-amino acid)s not only chelate Bi3+ but also exhibit reactive oxygen and nitrogen species (RONS) scavenging activity. In vitro and in vivo experiments demonstrate that Bi NPs have superior bimodal imaging performance, significantly enhanced CT contrast, and prolonged fluorescence signals, suggesting their great potential as bimodal contrast agents for diagnosis applications.

Single-Photon DNA Photocleavage up to 905 nm by a Benzylated 4-Quinolinium Carbocyanine Dye

This paper describes the DNA interactions of near-infrared (NIR) benzylated 4-quinolinium dicarbocyanine dyes containing a pentamethine bridge meso-substituted either with a bromine (4) or hydrogen (5) atom. In pH 7.0 buffered aqueous solutions, the 4-quinolinium dyes absorb light that extends into the near-infrared range up to ∼950 nm. The unique direct strand breakage of pUC19 DNA that is sensitized by irradiating either dicarbocyanine with an 850 nm LED laser constitutes the first published example of DNA photocleavage upon single-photon chromophore excitation at a wavelength greater than 830 nm. Brominated dye 4, which is more stable than and achieves DNA strand scission in higher yield than its hydrogen-bearing counterpart 5, cleaves plasmid DNA under 830 and 905 nm laser illumination. The addition of increasing amounts of DNA to aqueous pH 7.0 solutions converted an aggregated form of dye 4 to a monomer with bathochromic absorption that overlaps all three laser emission wavelengths. No induced circular dichroism and fluorescence signals were detected when DNA was present, pointing to possible external binding of the dye to the DNA. Experiments employing radical-specific fluorescent probes and chemical additives showed that brominated dye 4 likely breaks DNA strands by photosensitizing hydroxyl radical production. Micromolar concentrations of the dye were relatively nontoxic to cultured Escherichia coli cells in the dark but dramatically reduced survival of the cells under 830 nm illumination. As NIR light wavelengths deeply penetrate biological tissues, we envisage the future use of carbocyanine dyes as a sensitizing agent in phototherapeutic applications.

NIR-II Fluorescence Imaging-guided Photothermal Activated Pyroptosis For Precision Therapy Of Glioma

The resistance of cancer cells to apoptosis poses a significant challenge in cancer therapy, driving the exploration of alternative cell death pathways such as pyroptosis, known for its rapid and potent effects. While initial efforts focused on chemotherapy-induced pyroptosis, concerns about systemic inflammation highlight the need for precise activation strategies. Photothermal therapy emerges as a promising non-invasive technique, minimizing pyroptosis-related side effects by targeting tumors spatially and temporally. However, accurately pinpointing tumors to avoid collateral damage remains a challenge. Thus, we utilize NIR-II fluorescence imaging to achieve precise PTT-induced pyroptosis activation in glioma. A polymer semiconductor-based PTT agent was developed with high optical stability, integrated with mesoporous silica to enhance its biocompatibility. These nanoparticles, stabilized through PEG modification and targeted with cRGD peptides, effectively induced pyroptosis in vitro. Furthermore, this design facilitated precise tumor imaging guidance and subsequent pyroptosis activation in vivo, presenting a promising strategy for glioma therapy with minimized adverse effects.

The impact of indocyanine green fluorescence angiography (ICG-FA) on anastomotic leak rates and postoperative outcomes in colorectal anastomoses: a systematic review

BACKGROUND

Anastomotic leak (AL) is a major complication in colorectal surgery, significantly contributing to perioperative morbidity and mortality. Among strategies to prevent AL, Indocyanine Green Fluorescence Angiography (ICG-FA) has emerged as a promising method for assessing bowel perfusion intraoperatively. This systematic review evaluates the impact of ICG-FA on AL rates and other postoperative outcomes following colorectal anastomoses.

METHODS

A systematic search was conducted in PubMed, PubMed Central, MEDLINE, and Google Scholar, following PRISMA guidelines. Eligible studies included randomized controlled trials (RCTs), prospective cohort studies, and retrospective cohort studies comparing ICG-FA to controls in adult patients undergoing colorectal resections and anastomoses. Data on AL rates, intraoperative characteristics, and postoperative outcomes were extracted. Quality assessment was performed using the Newcastle-Ottawa Scale and the Revised Cochrane Risk-of-Bias Tool.

RESULTS

Sixteen studies (12 retrospective, 1 prospective, and 3 RCTs) involving 3231 patients (1562 ICG-FA and 1669 controls) were included. AL rates were significantly lower in the ICG-FA group (5.18%) compared to controls (11.50%) (p < 0.01). ICG-FA influenced surgical plans in 16.31% of cases. Operative time and ileostomy formation rates were comparable between groups. Reoperation, ileus, and wound infection rates showed minimal differences. Mortality rates were low in both groups (ICG-FA: 0.55%, control: 0.51%).

CONCLUSION

ICG-FA significantly reduces AL rates without increasing operative time or postoperative complications. This technique provides a reliable and safe assessment of bowel perfusion, supporting its integration into colorectal surgery protocols. Further high-quality RCTs are needed to confirm these findings and optimise its application.

Recent Advances in Indocyanine Green-Based Probes for Second Near-Infrared Fluorescence Imaging and Therapy

Fluorescence imaging, a highly sensitive molecular imaging modality, is being increasingly integrated into clinical practice. Imaging within the second near-infrared biological window (NIR-II; 1,000 to 1,700 nm), also referred to as shortwave infrared, has received substantial attention because of its markedly reduced autofluorescence, deeper tissue penetration, and enhanced spatiotemporal resolution as compared to traditional near-infrared (NIR) imaging. Indocyanine green (ICG), a US Food and Drug Administration-approved NIR fluorophore, has long been used in clinical applications, including blood vessel angiography, vascular perfusion monitoring, and tumor detection. Recent advancements in NIR-II imaging technology have revitalized interest in ICG, revealing its extended tail fluorescence beyond 1,000 nm and reaffirming its potential as a clinically translatable NIR-II fluorophore for in vivo imaging and theranostic applications for diagnosing various diseases. This review emphasizes the notable advances in the use of ICG and its derivatives for NIR-II imaging and image-guided therapy from both fundamental and clinical perspectives. We also provide a concise conclusion and discuss the challenges and future opportunities with NIR-II imaging using clinically approved fluorophores.

[Status Quo of Surgical Navigation]

Surgical navigation, also referred to as computer-assisted or image-guided surgery, is a technique that employs a variety of methods - such as 3D imaging, tracking systems, specialised software, and robotics to support surgeons during surgical interventions. These emerging technologies aim not only to enhance the accuracy and precision of surgical procedures, but also to enable less invasive approaches, with the objective of reducing complications and improving operative outcomes for patients. By harnessing the integration of emerging digital technologies, surgical navigation holds the promise of assisting complex procedures across various medical disciplines. In recent years, the field of surgical navigation has witnessed significant advances. Abdominal surgical navigation, particularly endoscopy, laparoscopic, and robot-assisted surgery, is currently undergoing a phase of rapid evolution. Emphases include image-guided navigation, instrument tracking, and the potential integration of augmented and mixed reality (AR, MR). This article will comprehensively delve into the latest developments in surgical navigation, spanning state-of-the-art intraoperative technologies like hyperspectral and fluorescent imaging, to the integration of preoperative radiological imaging within the intraoperative setting.

Opportunities and challenges of indocyanine green in gastrointestinal cancers for intraoperative and nano-medicine application

The morbidity and mortality of gastrointestinal tumours remain high worldwide. Surgical resection is currently the most critical radical therapeutic schedule, while postoperative complications and sentinel lymph node (SLN) identification are closely related to the outcome. Indocyanine green (ICG)-mediated fluorescence imaging is increasingly being used in gastrointestinal surgery. It has been embraced by various surgical disciplines as a potential method to improve lymph node detection and enhance surgical field visualization. ICG can passively concentrate in SLN because of enhanced permeation and retention effects. After excitation by near-infrared light devices, SLN can display higher intensity fluorescence, helping visualization for better lymph node dissection. In addition, visual assessment of intestinal blood flow through ICG may reduce the incidence of anastomotic leakage. Although it has good clinical application, ICG-imaging still faces some problems, such as a higher false-negative rate, poorly targeted biodistribution, and lower fluorescence contrast, due to the lack of active tumour targeting. Thus, different ICG-coupled nanoparticles with inherent characteristics or functional modification-enhanced SLN identification features for gastrointestinal cancers bring benefit through active tumour targeting, superior tumour-background ratio, and high resolution. Nano-ICG combined with potential substances, including enhanced imaging contrast and/or combination therapy (chemotherapy, targeted therapy, immunotherapy, etc.), have been packaged and accumulated in the tumour area through active targeting for multimodal imaging and treatment. In this review, we outline the intraoperative application and possible future nanodirections of ICG in gastrointestinal cancer. The prospects and challenges of nano-ICG diagnostic and therapeutic methods in clinical applications are also discussed.

Graphical Abstract

The use of near-infrared angiography in evaluating bowel anastomosis during a gynecologic oncology surgery

Reducing anastomotic leak rates after bowel resection is a priority among patients undergoing gynecologic oncology surgery. While near-infrared (NIR) angiography has been investigated in the colorectal literature, more recent work has demonstrated promising results when used in gynecologic cancer surgery. It has been repeatedly shown to be a safe intervention that can offer real time assessment of bowel perfusion, offering the surgeon the opportunity to act on the results in the hopes of decreasing the risk of complications.

Indocyanine green fluorescence in the evaluation of post-resection pancreatic remnant perfusion after a pancreaticoduodenectomy: a clinical study protocol

BACKGROUND

Pancreaticoduodenectomy is associated with an incidence of postoperative complications of approximately 41%. One of the most severe complications is a postoperative pancreatic fistula. The exact cause of postoperative fistula development is still unknown, but it appears to be multifactorial. Proper perfusion of pancreatic remnant is essential for the healing of pancreaticojejunostomy. To date, there is no method to reliably evaluate the vascular supply of the remnant. One of the methods for the assessment of organ perfusion is the indocyanine green fluorescence. This study aims to determine if indocyanine green fluorescence is a reliable method to measure the perfusion of the post-resection pancreatic remnant. The secondary outcome is to determine if intraoperative evaluation of the vascular supply of the post-resection remnant may predict the increased risk of postoperative pancreatic fistula development.

METHODS

This study is designed as a prospective, observational study. All consecutive patients undergoing open or robotic pancreaticoduodenectomies at our department during the 1st May 2024-31st December 2026 period will be enrolled. The exclusion criteria are an allergy to indocyanine green and refusal by the patient. The adequacy of the vascular supply of the post-resection pancreatic remnant will be intraoperatively evaluated using a fluorescence detector. Patients will be divided into two groups: Those with high risk of pancreatic fistula development and those with low risk. The incidence of pancreatic fistulas in both groups is to be compared. Postoperative data including morbidity, mortality, hospital stay, intensive care unit stay and postoperative fistula development will be collected.

DISCUSSION

If an intraoperative assessment of the perfusion of post-resection pancreatic remnant using indocyanine green is proven to be a suitable method to estimate the increased risk of the pancreatic fistula, the list of the existing known risk factors could be expanded. In the most high-risk patients the modification of the surgical procedure could be considered.

TRIAL REGISTRATION

Number: NCT06198400 ClinicalTrials.Gov. Date 08.01.2024.

"Rigid-Flexible" Dual-Ferrocene Chimeric Nanonetwork for Simultaneous Tumor-Targeted Tracing and Photothermal/Photodynamic Therapy

There is an urgent need to develop phototherapeutic agents with imaging capabilities to assess the treatment process and efficacy in real-time during cancer phototherapy for precision cancer therapy. The safe near-infrared (NIR) fluorescent dyes have garnered significant attention and are desirable for theranostics agents. However, until now, achieving excellent photostability and fluorescence (FL) imaging capability in aggregation-caused quenching (ACQ) dyes remains a big challenge. Here, for the only FDA-approved NIR dye, indocyanine green (ICG), we developed a dual-ferrocene (Fc) chimeric nanonetwork ICG@HFFC based on the rigid-flexible strategy through one-step self-assembly, which uses rigid Fc-modified hyaluronic acid (HA) copolymer (HA-Fc) and flexible octadecylamine (ODA) bonded Fc (Fc-C18) as the delivery system. HA-Fc reserved the ability of HA to target the CD44 receptor of the tumor cell surface, and the dual-Fc region provided a rigid space for securely binding ICG through metal-ligand interaction and π-π conjugation, ensuring excellent photostability. Additionally, the alkyl chain provided flexible confinement for the remaining ICG through hydrophobic forces, preserving its FL. Thereby, a balance is achieved between outstanding photostability and FL imaging capability. In vitro studies showed improved photobleaching resistance, enhanced FL stability, and increased singlet oxygen (1O2) production efficiency in ICG@HFFC. Further in vivo results display that ICG@HFFC had good tumor tracing ability and significant tumor inhibition which also exhibited good biocompatibility.. Therefore, ICG@HFFC provides an encouraging strategy to realize simultaneous enhanced tumor tracing and photothermal/photodynamic therapy (PTT/PDT) and offers a novel approach to address the limitations of ACQ dyes.

Indocyanine green near-infrared fluorescence-assisted video endoscopic inguinal lymph node dissection for rectal cancer: a single-center experience

BACKGROUND

This study aimed to investigate the safety and feasibility of indocyanine green near-infrared fluorescence (ICG-NIR) fluorescence-guided video-endoscopic inguinal lymphadenectomy (VEIL) for rectal cancer with inguinal lymph node metastasis (ILNM).

METHODS

A retrospective analysis was conducted on 11 patients with rectal cancer who underwent ICG-NIR fluorescence-guided VEIL, assessing various parameters such as operation time, intraoperative bleeding, number of harvested lymph nodes, intraoperative and postoperative complications, and follow-up.

RESULTS

Regarding surgical procedures for ILNM, unilateral surgery was performed in 7 cases (54.5%) and bilateral surgery in 4 cases (45.5%). Among these 15 ICG-NIR-guided VEIL surgeries in 11 patients, positive fluorescence visualization was achieved in 13 operations (86.7%). The median estimated blood loss was 10 ml, and the median operation time was 90 min. One case (6.7%) required conversion to open surgery. The median duration of the drain tube was 12 days, and the median length of postoperative hospital stay was 20 days. Postoperative complications were observed, including incisional infection in 2 cases (18.2%), lymphatic leakage in 5 cases (45.5%), urinary infection in 1 case (9.1%), and pneumonia in 3 cases (27.3%). Complications such as skin necrosis, lower limb venous thrombosis, lower limb swelling, or impaired movement were observed during the postoperative follow-up period. No cases of primary lesion, groin, or pelvic lymph node recurrence were observed.

CONCLUSION

ICG-NIR fluorescence-guided VEIL is a safe and feasible surgical treatment for rectal cancer with ILNM. ICG fluorescence guidance holds promise as a more personalized and precise approach for VEIL in rectal cancer surgery.

Bowel endometriosis: Surgical customization is demanding

Bowel endometriosis is the most common form of severe deep endometriosis. Surgery is an option in case of infertility and/or chronic pain or in the presence of a stenotic lesion. Clinical examination and preoperative imaging must provide an identity card of the lesion so that customized surgery can be proposed. The primary objective of this tailor-made surgery will always be to preserve the organ. The surgeon then has three options: shaving, discoid resection and segmental resection. The more extensive the resection, the greater the risk of severe short- and long-term complications. Surgery must therefore be adapted to the patient's specific situation and needs. Moreover, personalized care must extend beyond surgery. It must begin before the operation, preparing the patient for the operation like an athlete before a race, and continue afterwards by adapting the follow-up to the surgery performed.

Perfusion outcomes with near-infrared indocyanine green imaging system in laparoscopic total mesorectal excision for mid-rectal or low-rectal cancer (POSTER): a study protocol

INTRODUCTION

Anastomotic leakage (AL) is defined as the failure of complete healing or disruption of the anastomosis subsequent to rectal cancer surgery, resulting in the extravasation of intestinal contents into the intra-abdominal or pelvic cavity. It is a serious complication of rectal cancer surgery, accounting for a considerable increase in morbidity and mortality. The use of fluorescence imaging technology in surgery allows surgeons to better evaluate blood perfusion. However, the conclusions of some existing studies are not consistent, so a consensus on whether the near-infrared indocyanine green (NIR-ICG) imaging system can reduce the incidence of AL is needed.

METHODS

This POSTER trial is designed as a multicentre, prospective, randomised controlled clinical study adhering to the "population, interventions, comparisons, outcomes (PICO)" principles. It is scheduled to take place from August 2019 to December 2024 across eight esteemed hospitals in China. The target population consists of patients diagnosed with rectal cancer through pathological confirmation, with tumours located≤10 cm from the anal verge, eligible for laparoscopic surgery. Enrolled patients will be randomly assigned to either the intervention group or the control group. The intervention group will receive intravenous injections of ICG twice, with intraoperative assessment of anastomotic blood flow using the near-infrared NIR-ICG system during total mesorectal excision (TME) surgery. Conversely, the control group will undergo conventional TME surgery without the use of the NIR-ICG system. A 30-day follow-up period postoperation will be conducted to monitor and evaluate occurrences of AL. The primary endpoint of this study is the incidence of AL within 30 days postsurgery in both groups. The primary outcome investigators will be blinded to the application of ICG angiography. Based on prior literature, we hypothesise an AL rate of 10.3% in the control group and 3% in the experimental group for this study. With a planned ratio of 2:1 between the number of cases in the experimental and control groups, and an expected 20% lost-to-follow-up rate, the initial estimated sample size for this study is 712, comprising 474 in the experimental group and 238 in the control group.

ETHICS AND DISSEMINATION

This study has been approved by Ethics committee of Beijing Friendship Hospital, Capital Medical University (approval number: 2019-P2-055-02). The results will be disseminated in major international conferences and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04012645.

Dual Tumor-Selective β-Carboline-Based Fluorescent Probe for High-Contrast/Rapid Diagnosis of Clinical Tumor Tissues

Given that precise/rapid intraoperative tumor margin identification is still challenging, novel fluorescent probes HY and HYM, based on acidic tumor microenvironment (TME) activation and organic anion transporting polypeptide (OATPs)-mediated selective uptake, were constructed and synthesized. Both of them possessed acidic pH-activatable and reversible fluorescence as well as large Stokes shift. Compared with HY, HYM had a higher (over 9-fold) enhancement in fluorescence with pH ranging from 7.6 to 4.0, and the fluorescence quantum yield of HYM (ΦF = 0.49) at pH = 4.0 was 8-fold stronger than that (ΦF = 0.06) at pH = 7.4. Mechanism research demonstrated that acidic TME-induced protonation of the pyridine N atom on β-carbolines accounted for the pH-sensitive fluorescence by influencing the intramolecular charge transfer (ICT) effect. Furthermore, HYM selectively lit up cancer cells and tumor tissues not only by "off-on" fluorescence but also by OATPs (overexpressed on cancer cells)-mediated cancer cellular internalization, offering dual tumor selectivity for precise visualization of tumor mass and intraoperative guidance upon in situ spraying. Most importantly, HYM enabled rapid and high-contrast (tumor-to-normal tissue ratios > 6) human tumor margin identification in clinical tumor tissues by simple spraying within 6 min, being promising for aiding in clinical surgical resection.

Minimally invasive surgery for deep endometriosis

Deep endometriosis (DE) is endometriotic tissue that invades the peritoneum by >5 mm. Surgery is the treatment of choice for symptomatic DE, and laparoscopic surgery is preferred over laparotomy due to better vision and postoperative pain. In this review, we aimed to collect and summarize recent literature on DE surgery and share laparoscopic procedures for rectovaginal and bowel endometriosis.

The value of ICG-guided left colon vascular variation and anatomical rules for the radical resection of proctosigmoid colon cancer

Objective

During laparoscopic radical resection for proctosigmoid colon cancer (PCC), surgeons could inadvertently damage the arteries when following the operation path.This study investigated the variations in left colon blood vessels in order to guide the scientific protection of the marginal artery (MA) during laparoscopic surgery for PCC.

Methods

Data from seven patients who underwent inferior mesenteric artery (IMA) angiography were included as imaging references to preliminarily explore the vascular structure and variation in the left colon. The clinical video data of 183 PCC patients were retrospectively analyzed to observe intraoperative MA injury. Meanwhile, a prospective cohort of 96 patients with the same disease underwent intraoperative indocyanine green (ICG) fluorescence imaging of the peripheral sigmoid artery network, the variation of marginal arteries was summarized, and the distance between vessels and the bowel was measured at different levels. Patients were divided into 'ICG group' and 'non-ICG group' according to whether ICG guidance was performed, and perioperative conditions were compared between the two groups. Taking the integrity of lymph node dissection into consideration, 18 patients underwent carbon nanonode tracing. This study was conducted under the standard consent and ethical approval of the Ethics Committee of our center.

Results

7 patients with IMA angiography shared some vascular structures, defined as 'Dangerous Triangle' and 'Secure Window'. Through intraoperative observation, the primary arch was typically located 4.2 (2.3-6.0) cm away from the intestinal canal, and 5.21% (5/96) patients had poor anastomosis at the primary arch. Moreover, secondary vascular arches (6.4 (4.6-10.0) cm from the intestinal wall) were observed in 38.54% of patients. MA injury was identified in 2 of 183 cases, and the ischemic bowel was timely dissected, whereas no such injury occurred during ICG fluorescenceguided surgery. Guided by carbon nanoparticles, the integrity of lymph node dissection can be maintained while preserving the secondary arch in all patients.

Conclusions

This study demonstrated the benefits of ICG guidance in protecting the intestinal blood supply in laparoscopic PCC surgery. By enhancing the understanding of primary and secondary vascular arches, secure windows, and dangerous triangles, surgeons can safely optimize the surgical path during surgery.

Endoscopic ultrasound-guided injection of carbon nanoparticles suspension to label rectal cancer before neoadjuvant chemoradiotherapy: a retrospective cohort study

Background

Localization of the primary tumor and ensuring safe distal surgical margins (DSMs) following neoadjuvant chemoradiotherapy (nCRT) are challenging in locally advanced rectal cancers (LARCs). This study investigated the effectiveness of carbon nanoparticles suspension (CNS) for labeling the primary tumor and allowing precise tumor resection after nCRT.

Methods

Clinicopathological data of LARC patients who underwent nCRT followed by laparoscopic radical anal preservation surgery at our center between January 2018 and February 2023 were prospectively collected. The patients were divided into the CNS tattooed (CNS) and non-tattooed (control) groups. In the CNS group, CNS was injected in four quadrants on the anal side 1 cm away from the lower tumor margin. DSMs were determined through intraoperative distal rectal examination in the control group and observation of CNS tattoos in the CNS group. DSM lengths and positive DSM rates were compared between the two groups to analyse the feasibility and effectiveness of CNS for labeling LARCs before nCRT.

Results

There was no statistically significant difference in the basic demographic data, effectiveness of nCRT, or post-operative recovery rates between the two groups (all P > 0.05). In the CNS group, CNS tattoos were observed on the outside of the rectal wall, with an overall efficiency of 87.1% (27/31). The CNS group had fewer positive DSMs and safer DSM lengths (2.73 ± 0.88 vs 2.12 ± 1.15 cm, P = 0.012) than the control group (P < 0.05).

Conclusions

Endoscopic ultrasound-guided injection of CNS tattoos before nCRT could effectively label the LARCs, ensuring safe DSMs during anus-preserving surgeries (Chictr.org.cn No.: ChiCTR2300068991).

Lymphatic flow mapping during colon cancer surgery using indocyanine green fluorescence imaging

With the development of surgical technology, indocyanine green (ICG) fluorescence navigation systems may be useful in various areas of colorectal surgery, including tumor location confirmation, bowel perfusion, ureter identification, and lymph node mapping. This review provides an overview of the current status of ICG-based navigation surgery in colorectal surgery, emphasizing its role in lymphatic flow mapping. This state-of-the-art approach will allow for appropriate oncological surgeries in the field of colorectal cancer and improve the patient's prognosis.

Application of near-infrared fluorescence imaging in theranostics of gastrointestinal tumors

Gastrointestinal cancers have become an important cause of cancer-related death in humans. Improving the early diagnosis rate of gastrointestinal tumors and improving the effect of surgical treatment can significantly improve the survival rate of patients. The conventional diagnostic method is high-definition white-light endoscopy, which often leads to missed diagnosis. For surgical treatment, intraoperative tumor localization and post-operative anastomotic state evaluation play important roles in the effect of surgical treatment. As a new imaging method, near-infrared fluorescence imaging (NIRFI) has its unique advantages in the diagnosis and auxiliary surgical treatment of gastrointestinal tumors due to its high sensitivity and the ability to image deep tissues. In this review, we focus on the latest advances of NIRFI technology applied in early diagnosis of gastrointestinal tumors, identification of tumor margins, identification of lymph nodes, and assessment of anastomotic leakage. In addition, we summarize the advances of NIRFI systems such as macro imaging and micro imaging systems, and also clearly describe the application process of NIRFI from system to clinical application, and look into the prospect of NIRFI applied in the theranostics of gastrointestinal tumors.

Tailoring renal-clearable zwitterionic cyclodextrin for colorectal cancer-selective drug delivery

Although cyclodextrin-based renal-clearable nanocarriers have a high potential for clinical translation in targeted cancer therapy, their designs remain to be optimized for tumour retention. Here we report on the design of a tailored structure for renal-clearable zwitterionic cyclodextrin for colorectal cancer-selective drug delivery. Twenty cyclodextrin derivatives with different charged moieties and spacers are synthesized and screened for colloidal stability. The resulting five candidates are evaluated for biodistribution and an optimized structure is identified. The optimized cyclodextrin shows a high tumour accumulation and is used for delivery of doxorubicin and ulixertinib. Higher tumour accumulation and tumour penetration facilitates tumour elimination. The improved antitumour efficacy is demonstrated in heterotopic and orthotopic colorectal cancer models.

Preservation of left colic artery in laparoscopic colorectal operation: The benefit challenge

BACKGROUND

During laparoscopic resection for colorectal cancer, there is controversy regarding whether the left colic artery (LCA) should be preserved at its origin.

AIM

To investigate the prognostic significance of preservation of the LCA in colorectal cancer surgery.

METHODS

Patients were divided into two groups. The high ligation (H-L) technique (refers to ligation performed 1 cm from the beginning of the inferior mesenteric artery) group consisted of 46 patients, and the low ligation (L-L) technique (refers to ligation performed below the initiation of the LCA) group consisted of 148 patients. Operative time, blood loss, lymph nodes with tumor invasion, postoperative complications and recovery time, recurrence rate, and 5-year survival rate were compared between the two groups.

RESULTS

The average number of lymph nodes detected in postoperative pathological specimens was 17.4/person in the H-L group and 15.9/person in the L-L group. There were 20 patients (43%) with positive lymph nodes (lymph node metastasis) in the H-L group and 60 patients (41%) in the L-L group. No statistical differences were found between the groups. Complications occurred in 12 cases (26%) in the H-L group and in 26 cases (18%) in the L-L group. The incidences of postoperative anastomotic complications and functional urinary complications were significantly lower in the L-L group. The 5-year survival rates in H-L and L-L groups were 81.7% and 81.6%, respectively, and relapse-free survival rates were 74.3% and 77.1%, respectively. The two groups were similar statistically.

CONCLUSION

Complete mesenteric resection combined with lymph node dissection around the inferior mesenteric artery root while preserving the LCA is a beneficial surgical approach during laparoscopic resection for colorectal cancer.

Indocyanine green fluorescence angiography decreases the risk of anastomotic leakage after rectal cancer surgery: a systematic review and meta-analysis

Background

Anastomotic leakage is a serious complication after rectal cancer resection. Intraoperative use of indocyanine green fluorescence angiography (ICGFA) can help prevent anastomotic leakage, but its use is controversial. We conducted a systematic review and meta-analysis to determine the efficacy of ICGFA in reducing anastomotic leakage.

Methods

Relevant data and research published until September 30, 2022, was retrieved from the PubMed, Embase, and Cochrane Library databases, and the difference in the incidence of anastomotic leakage after rectal cancer resection between ICGFA and standard treatment was compared.

Results

This meta-analysis included 22 studies with a total of 4,738 patients. The results showed that ICGFA use during surgery decreased the incidence of anastomotic leakage after rectal cancer surgery [risk ratio (RR) = 0.46; 95% confidence interval (95% CI), 0.39-0.56; p < 0.001]. Simultaneously, in subgroup analyses for different regions, ICGFA was found to be used to reduce the incidence of anastomotic leakage after rectal cancer surgery in Asia (RR = 0.33; 95% CI, 0.23-0.48; p < 0.00001) and Europe (RR = 0.38; 95% CI, 0.27-0.53; p < 0.00001) but not in North America (RR = 0.72; 95% CI, 0.40-1.29; p = 0.27). Regarding different levels of anastomotic leakage, ICGFA reduced the incidence of postoperative type A anastomotic leakage (RR = 0.25; 95% CI, 0.14-0.44; p < 0.00001) but did not reduce the incidence of type B (RR = 0.70; 95% CI, 0.38-1.31; p = 0.27) and type C (RR = 0.97; 95% CI, 0.51-1.97; p = 0.93) anastomotic leakages.

Conclusion

ICGFA has been linked to a reduction in anastomotic leakage after rectal cancer resection. However, multicenter randomized controlled trials with larger sample sizes are required for further validation.

Low-Dose NIR-II Preclinical Bioimaging Using Liposome-Encapsulated Cyanine Dyes

Fluorescence imaging in the second near-infrared window (NIR-II, 1000-1700 nm) provides a powerful tool for in vivo structural and functional imaging in deep tissue. However, the lack of biocompatible contrast agents with bright NIR-II emission has hindered its application in fundamental research and clinical trials. Herein, a liposome encapsulation strategy for generating ultrabright liposome-cyanine dyes by restricting dyes in the hydrophobic pockets of lipids and inhibiting the aggregation, as corroborated by computational modeling, is reported. Compared with free indocyanine green (ICG, an US Food and Drug Administration-approved cyanine dye), liposome-encapsulated ICG (S-Lipo-ICG) shows a 38.7-fold increase in NIR-II brightness and enables cerebrovascular imaging at only one-tenth dose over a long period (30 min). By adjusting the excitation wavelength, two liposome-encapsulated cyanine dyes (S-Lipo-ICG and S-Lipo-FD1080) enable NIR-II dual-color imaging. Moreover, small tumor nodules (2-5 mm) can be successfully distinguished and removed with S-Lipo-ICG image-guided tumor surgery in rabbit models. This liposome encapsulation maintains the metabolic pathway of ICG, promising for clinical implementation.

In Vivo Evaluation of a Gallium-68-Labeled Tumor-Tracking Cyanine Dye for Positron Emission Tomography/Near-Infrared Fluorescence Carcinoma Imaging, Image-Guided Surgery, and Photothermal Therapy

Positron emission tomography (PET)/near-infrared fluorescence (NIRF) dual-modal imaging presents an enticing prospect for tumor diagnosis and surgical navigation. In this study, we developed a novel probe IR808-DOTA for tumor-targeted PET/NIRF imaging, image-guided surgery, and photothermal therapy. This construct had better water solubility and pharmacokinetics than IR808 and had similar photophysical properties, tumor targeting ability, and photothermal anticancer effect to IR808. By a simple labeling process, IR808-DOTA was labeled with gallium-68 and applied as a PET probe for tumor imaging in MCF-7 tumor xenografted mice. IR808-DOTA itself acted as an NIRF imaging agent in the following surgery for intraoperative navigation to aid surgeons in the delineation of tumor margins and visualizing sentinel lymph nodes to facilitate a more thorough tumor resection. Irradiation by laser, IR808-DOTA could prominently inhibit tumor growth in MCF-7 subcutaneous tumor model mice by directly ablating tumor cells, inhibiting tumor proliferation, and promoting tumor cell apoptosis. In summary, ⁶⁸Ga-DOTA-IR808 could enable a convenient and user-friendly workflow for tumor imaging and guided surgery, and therefore, it may have great prospects for clinical translation as a PET/NIRF dual-modal probe.

Interobserver Variability in the Assessment of Fluorescence Angiography in the Colon

BACKGROUND

Fluorescence angiography in colorectal surgery is a technique that may lead to lower anastomotic leak rates. However, the interpretation of the fluorescent signal is not standardised and there is a paucity of data regarding interobserver agreement. The aim of this study is to assess interobserver variability in selection of the transection point during fluorescence angiography before anastomosis.

METHODS

An online survey with still images of fluorescence angiography was distributed through colorectal surgery channels containing images from 13 patients where several areas for transection were displayed to be chosen by raters. Agreement was assessed overall and between pre-planned rater cohorts (experts vs non-experts; trainees vs consultants; colorectal specialists vs non colorectal specialists), using Fleiss' kappa statistic.

RESULTS

101 raters had complete image ratings. No significant difference was found between raters when choosing a point of optimal bowel transection based on fluorescence angiography still images. There was no difference between pre-planned cohorts analysed (experts vs non-experts; trainees vs consultants; colorectal specialists vs non colorectal specialists). Agreement between these cohorts was poor (<.26).

CONCLUSION

Whilst there is no learning curve for the technical adoption of FA, understanding the fluorescent signal characteristics is key to successful use. We found significant variation exists in interpretation of static fluorescence angiography data. Further efforts should be employed to standardise fluorescence angiography assessment.

Indocyanine green (ICG) fluorescent cholangiography in laparoscopic cholecystectomy: Simplifying time and dose

BACKGROUND

This article aims to analyze and to simplify the optimal dose and time of intravenous indocyanine green (ICG) administration to achieve the identification of the cystic duct and the common bile duct (CBD).

METHODS

A consecutive series of 146 patients was prospectively analyzed and divided into three groups according to the time of ICG administration: at induction of anesthesia group (20-30 min); hours before group (between 2 and 6 h); and the day before group (≥6 h); and two groups according to the dose of ICG: 1 cc (2.5 mg) or weight-based dose (0.05 mg/kg).

RESULTS

The CBD was better visualized in the at induction of anesthesia group (85.4%), in the hours before group (97.1%) (p = 0.002) and in the 1cc group (p = 0.011). When we analyzed the 1 cc group (n = 126) a greater visualization of the CBD was observed in the at induction of anesthesia group (86.7%) and in the hours before group (97.1%) (p = 0.027).

CONCLUSION

Due to its simplicity and reproducibility, we suggest a dose of 2.5 mg administered 2-6 h before the procedure is the optimal. However, ICG administered 30 min prior to the surgery is enough for adequate visualization of biliary structures.

Consensus Statement on the Use of Near-Infrared Fluorescence Imaging during Pancreatic Cancer Surgery Based on a Delphi Study: Surgeons' Perspectives on Current Use and Future Recommendations

Indocyanine green (ICG) is one of the only clinically approved near-infrared (NIR) fluorophores used during fluorescence-guided surgery (FGS), but it lacks tumor specificity for pancreatic ductal adenocarcinoma (PDAC). Several tumor-targeted fluorescent probes have been evaluated in PDAC patients, yet no uniformity or consensus exists among the surgical community on the current and future needs of FGS during PDAC surgery. In this first-published consensus report on FGS for PDAC, expert opinions were gathered on current use and future recommendations from surgeons' perspectives. A Delphi survey was conducted among international FGS experts via Google Forms. Experts were asked to anonymously vote on 76 statements, with ≥70% agreement considered consensus and ≥80% participation/statement considered vote robustness. Consensus was reached for 61/76 statements. All statements were considered robust. All experts agreed that FGS is safe with few drawbacks during PDAC surgery, but that it should not yet be implemented routinely for tumor identification due to a lack of PDAC-specific NIR tracers and insufficient evidence proving FGS's benefit over standard methods. However, aside from tumor imaging, surgeons suggest they would benefit from visualizing vasculature and surrounding anatomy with ICG during PDAC surgery. Future research could also benefit from identifying neuroendocrine tumors. More research focusing on standardization and combining tumor identification and vital-structure imaging would greatly improve FGS's use during PDAC surgery.

Novel intraoperative near-infrared imaging strategy to identify abnormalities in the anterior mediastinum

Thoracic surgeons are frequently asked to biopsy suspicious tissues in the anterior mediastinum to discriminate between a reactive versus malignant pathology such as lymph nodes. The most common benign cause of a mediastinal lymph node is a reactive lymph node from a prior infection or inflammatory process such as post-COVID or granulomatous disease. The most common malignant cause is a lymphoproliferative disorder but also metastatic disease from neck, breast and other regional cancers. Biopsies in this location are challenging because they are far from the trachea and the sternum is a barrier to most diagnostic procedures. Thus, a surgical biopsy is frequently required and a common procedure for Thoracic surgeons. Technically, identifying these lesions can be challenging, particularly for small lesions or those in patients with high body mass index. In order to improve contrast between diseased tissue in the anterior mediastinum and surrounding adipose tissue, we have been studying near-infrared imaging during surgery using indocyanine green (ICG) to give contrast to the abnormal tissues and to avoid an unnecessary extended resection. We developed a modified technique to give ICG to a patient during a biopsy in the anterior mediastinum to specifically highlight abnormal tissues. As a proof-of-principle, we present a case of a young woman with a suspicious 2 cm mediastinal lymph node that required surgical biopsy.

The use of near-infrared imaging with indocyanine green in the ovarian tissue transplantation: a case report

The request for fertility preservation has consistently increased in recent years. To our knowledge this case report is the first to describe the application of near-infrared intraoperative imaging using indocyanine green (NIR-ICG) during ovarian tissue transplantation (OTT), to assist surgeon choosing the site of implantation of ovarian fragments. OTT was performed in a 42-year-old woman using NIR-ICG to evaluate the vascularisation of peritoneal area as the site of implantation for the ovarian graft. we believe this new approach could be useful in identifying the best reimplantation site.

Anastomotic leak test using indocyanine green during laparoscopic Roux-en-Y gastric bypass: A cohort study

BACKGROUND

Indocyanine green (ICG) can be injected into the human bloodstream and it allows us to show stomach vascularity in real time. The aim of our study is to observe the preliminary results of the application of indocyanine green fluorescence (IGF) during laparoscopic Roux-en-Y Gastric Bypass (RYGB in our center and how the perfusion of the gastro-jejunal anastomosis affects the onset of fistula.

MATERIALS AND METHODS

30 consecutive patients underwent RYGB with ICG fluorescence angiography at our center from January 2020 to December 2021.5 ml of ICG were then injected intravenously to identify the blood supply of the stomach and the gastro-jejunal anastomosis. The UIN for ClinicalTrial.gov Protocol Registration and Results System is: NCT05476159 for the Organization UFoggia.

RESULTS

In the RYGB tested with ICG, we all have adequate perfusion but despite this a methylene blue test was positive and allowed us to reinforce the suture of the gastro-jejunal anastomosis.

CONCLUSION

Intraoperative ICG testing during laparoscopic RYGB may be helpful in determining which patients are at an increased risk for leakage but multiple factors concur to the pathophysiology and the incidence of gastric fistula not only the perfusion.

Delphi survey of intercontinental experts to identify areas of consensus on the use of indocyanine green angiography for tissue perfusion assessment during plastic and reconstructive surgery

BACKGROUND

In recent years, indocyanine green angiography (ICG-A) has been used increasingly to assist tissue perfusion assessments during plastic and reconstructive surgery procedures, but no guidelines exist regarding its use. We sought to identify areas of consensus and non-consensus among international experts on the use of ICG-A for tissue-perfusion assessments during plastic and reconstructive surgery.

METHODS

A two-round, online Delphi survey was conducted of 22 international experts from four continents asking them to vote on 79 statements divided into five modules: module 1 = patient preparation and contraindications (n = 11 statements); module 2 = ICG administration and camera settings (n = 17); module 3 = other factors impacting perfusion assessments (n = 10); module 4 = specific indications, including trauma debridement (n = 9), mastectomy skin flaps (n = 6), and free flap reconstruction (n = 8); and module 5 = general advantages and disadvantages, training, insurance coverage issues, and future directions (n = 18). Consensus was defined as ≥70% inter-voter agreement.

RESULTS

Consensus was reached on 73/79 statements, including the overall value, advantages, and limitations of ICG-A in numerous surgical settings; also, on the dose (0.05 mg/kg) and timing of ICG administration (∼20-60 seconds preassessment) and best camera angle (61-90^o) and target-to-tissue distance (20-30 cm). However, consensus also was reached that camera angle and distance can vary, depending on the make of camera, and that further research is necessary to technically optimize this imaging tool. The experts also agreed that ambient light, patient body temperature, and vasopressor use impact perfusion assessments.

CONCLUSION

ICG-A aids perfusion assessments during plastic and reconstructive surgery and should no longer be considered experimental. It has become an important surgical tool.

Use of fluorescence imaging and indocyanine green during laparoscopic cholecystectomy: Results of an international Delphi survey

BACKGROUND

Published empirical data have increasingly suggested that using near-infrared fluorescence cholangiography during laparoscopic cholecystectomy markedly increases biliary anatomy visualization. The technology is rapidly evolving, and different equipment and doses may be used. We aimed to identify areas of consensus and nonconsensus in the use of incisionless near-infrared fluorescent cholangiography during laparoscopic cholecystectomy.

METHODS

A 2-round Delphi survey was conducted among 28 international experts in minimally invasive surgery and near-infrared fluorescent cholangiography in 2020, during which respondents voted on 62 statements on patient preparation and contraindications (n = 12); on indocyanine green administration (n = 14); on potential advantages and uses of near-infrared fluorescent cholangiography (n = 18); comparing near-infrared fluorescent cholangiography with intraoperative x-ray cholangiography (n = 7); and on potential disadvantages of and required training for near-infrared fluorescent cholangiography (n = 11).

RESULTS

Expert consensus strongly supports near-infrared fluorescent cholangiography superiority over white light for the visualization of biliary structures and reduction of laparoscopic cholecystectomy risks. It also offers other advantages like enhancing anatomic visualization in obese patients and those with moderate to severe inflammation. Regarding indocyanine green administration, consensus was reached that dosing should be on a milligrams/kilogram basis, rather than as an absolute dose, and that doses >0.05 mg/kg are necessary. Although there is no consensus on the optimum preoperative timing of indocyanine green injections, the majority of participants consider it important to administer indocyanine green at least 45 minutes before the procedure to decrease the light intensity of the liver.

CONCLUSION

Near-infrared fluorescent cholangiography experts strongly agree on its effectiveness and safety during laparoscopic cholecystectomy and that it should be used routinely, but further research is necessary to establish optimum timing and doses for indocyanine green.

“Light green up”: Indocyanine Green Fluorescence Imaging–guided Robotic Bilateral Inguinal Lymphadenectomy by the Hypogastric Subcutaneous Approach for Penile Cancer

Background

Inguinal lymphadenectomy is of great significance in the management of penile cancer, which aims to mitigate the progression of lymph node metastasis. It is important to improve the efficiency of lymph node dissection and reduce surgical complications.

Objective

To detail a novel technique for robotic bilateral inguinal lymphadenectomy through the hypogastric subcutaneous approach by indocyanine green (ICG) fluorescence imaging, which promotes the identification and dissection of inguinal lymph nodes with considerable safety.

Design, setting, and participants

Ten eligible penile cancer patients who underwent ICG fluorescence imaging–guided robotic bilateral inguinal lymphadenectomy were prospectively enrolled (ICG group). Sixteen patients who underwent the surgery without ICG were retrospectively set as the control (non-ICG) group. Follow-up records for at least 12 mo were required.

Surgical procedure

Inguinal lymphadenectomy was performed by the hypogastric subcutaneous approach. The ICG solution was subcutaneously injected into the prepuce at the beginning of surgery, and ICG fluorescence imaging–guided robotic-assisted bilateral inguinal lymphadenectomy was conducted.

Measurements

Clinical outcomes were collected. The primary study outcome measurement was the number of dissected inguinal lymph nodes.

Results and limitations

The numbers of inguinal overall, superficial, and deep lymph nodes retrieved were all higher in the ICG than in the non-ICG group (p < 0.05). No patients had severe perioperative complications. No difference was found in the overall complication rate and 12-mo survival between two groups (p > 0.05).

Conclusions

ICG fluorescence imaging–guided robotic inguinal lymphadenectomy via the hypogastric subcutaneous approach is feasible and safe for patients with penile cancer, which is beneficial for dissecting more inguinal lymph nodes with few surgical complications.

Patient summary

We developed a promising indocyanine green fluorescence imaging–guided technique to perform robotic bilateral inguinal lymphadenectomy on patients with penile cancer, which conduces to remove more inguinal lymph nodes with limited complications.

Intraoperative bowel perfusion quantification with hyperspectral imaging: a guidance tool for precision colorectal surgery

BACKGROUND

Poor anastomotic perfusion can cause anastomotic leaks (AL). Hyperspectral imaging (HSI), previously validated experimentally, provides accurate, real-time, contrast-free intestinal perfusion quantification. Clinical experience with HSI is limited. In this study, HSI was used to evaluate bowel perfusion intraoperatively.

METHODS

Fifty-two patients undergoing elective colorectal surgeries for neoplasia (n = 40) or diverticular disease (n = 12), were enrolled. Intestinal perfusion was assessed with HSI (TIVITA®, Diaspective Vision, Am Salzhaff, Germany). This device generates a perfusion heat map reflecting the tissue oxygen saturation (StO2) amount. Prior to anastomose creation, the clinical transection line (CTL) was highlighted on the proximal bowel and imaged with HSI. Upon StO2 heat map evaluation, the hyperspectral transection line (HTL) was identified. In case of CTL/HTL discrepancy > 5 mm, the bowel was always resected at the HTL. HSI outcomes were compared to the clinical ones.

RESULTS

AL occurred in one patient who underwent neoadjuvant radiochemotherapy and ultralow anterior resection for rectal cancer. HSI assessment was feasible in all patients, and StO2-values were significantly higher at proximal segments than distal ones. Twenty-six patients showed CTL/HTL discrepancy, and these patients had a lower mean StO2 (54.55 ± 21.30%) than patients without discrepancy (65.10 ± 21.30%, p = 0.000). Patients undergoing neoadjuvant radiochemotherapy showed a lower StO2 (51.41 ± 23.41%) than non-neoadjuvated patients (60.51 ± 24.98%, p = 0.010).

CONCLUSION

HSI is useful in detecting intraoperatively marginally perfused segments, for which the clinical appreciation is unreliable. Intestinal vascular supply is lower in patients undergoing neoadjuvant radiochemotherapy, and this novel finding together with the clinical impact of HSI perfusion quantification deserves further investigation in larger trials.

Meta analysis of indocyanine green fluorescence in patients undergoing laparoscopic colorectal cancer surgery

This meta-analysis intended to systematically evaluate the clinical implications of indocyanine green fluorescence (ICG) in patients undergoing laparoscopic colorectal surgery. PubMed, MEDLINE, Cochrane Library, EMBASE, China National Knowledge Infrastructure (CNKI), Wanfang Database, VIP Medical Information System and China Biomedical Database were synthetically searched for studies published from inception to April 14, 2022. The randomized controlled trials comparing ICG-use with controls were selected. The incidence of anastomotic leakage (AL), lymph node detection, operation duration, intraoperative bleeding, postoperative morbidity, and hospitalization time were evaluated in summary analysis, and calculated the corresponding 95% confidence intervals (CI). Subsequently, in addition to subgroup analyses, studies for heterogeneity, sensitivity, and publication bias were carried out. Consequently, 3453 patients in the enrolled 15 studies were included; 1616 patients were allocated to the experimental group, and 1837 patients were assigned to the control group. The ICG group had a significantly decreased risk of AL (RR: 0.50, 95% CI: 0.37-0.67) and shorter hospitalization time (SMD: -0.31, 95% CI: -0.54-0.08) compared to the control group. Meanwhile, the ICG showed clearly better lymph node detection (SMD: 0.19, 95% CI: 0.02-0.36). However, when the content of operation duration (SMD: -0.07, 95% CI: -0.30-0.15) and intraoperative bleeding (SMD: -0.16, 95% CI: -0.35-0.04) were compared, no statistical significance was found. Furthermore, the pooled analysis of postoperative morbidity was not statistically significant (RR:0.79, 95% CI: 0.58-1.08). The results of the subgroup analysis of AL indicated that there may be regional variations in AL (RR: 0.50, 95% CI: 0.37-0.67) but not in postoperative morbidity (RR: 0.79, 95% CI: 0.58-1.08). In conclusion, the application of ICG in laparoscopic colorectal surgery can effectively reduce the AL, lymph node detection, and hospitalization time. However, more multicenter large-sample randomized controlled trials are required to further confirm its advantages. The meta-analysis was registered in PROSPERO (no. CRD42022288054).

Burden of Colovesical Fistula and Changing Treatment Pathways: A Systematic Literature Review

PURPOSE

Colovesical fistula (CVF) is a rare complication of sigmoid diverticulitis causing significant morbidity and quality of life impairment. Aim of this study was to analyze contemporary literature data to appraise the current standard of care and changes of treatment algorithms over time.

MATERIALS AND METHODS

A systematic review of the literature on surgical management of CVF was conducted through PUBMED, EMBASE, and COCHRANE databases, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines.

RESULTS

Fourteen papers published between 2014 and 2020 and including 1061 patients were analyzed. One-stage colonic resection with primary anastomosis, with or without loop ileostomy, was the most common surgical procedure. A laparoscopic or robotic approach was attempted in 39.5% of patients, and conversion rate to open surgery was 7.8%. Clavien-Dindo grade ≥3 complication rate, 30-day mortality, and recurrence rate were 7.4%, 1.5%, and 0.5%, respectively.

CONCLUSIONS

Minimally invasive sigmoidectomy with primary anastomosis is safe and should be the first-choice approach for CVF. Bladder repair is not necessary after a negative intraoperative leak test. A standardized perioperative care can improve clinical outcomes and reduce the length of hospital stay and the duration of Foley catheterization.

Tumor-Targeting NIRF/MR Dual-Modal Molecular Imaging Probe for Surgery Navigation

Multimodality imaging recognized as a promising monitoring strategy can serve the needs of accurate diagnosis and treatment of cancer by providing molecular and anatomic information about tumor sites. However, the probes based on multiple imaging modalities for surgery navigation remain limited due to poor biocompatibility and tumor targeting specificity. Herein, we present a small-molecule near-infrared fluorescence/magnetic resonance (NIRF/MR) imaging probe, Gd-NMC-3, covalently coupled with DCDSTCY and Gd-DOTA via butane diamine, for precise detection and intraoperative visualization. The in vitro and in vivo studies demonstrated that Gd-NMC-3 could be effectively accumulated in tumor sites as a bimodal imaging molecule exhibiting significant fluorescence accumulation and reasonable relaxation property in tumors with low cytotoxicity and good biocompatibility. Furthermore, Gd-NMC-3 was successfully applied to provide real-time visual navigation in LM3 orthotopic and subcutaneous tumor models to guide the resection of tumors. Importantly, no more fluorescence was observed in mice after operation, implying the total removal of tumor tissues. In conclusion, Gd-NMC-3 has great potential to be applied in the clinic based on its high resolution and sensitivity in tumor imaging.

Mapping the Mesentery Using ICG

Indocyanine green (ICG) fluorescent imaging has been used in colorectal surgery to assess intraoperative blood flow to the colon. However, its use has expanded to allow imaging of the lymphatic drainage within the mesentery in cancer resections. This technique can been used for real-time visualization of lymph nodes, and the detection of sentinel lymph nodes, lateral sidewall nodes, metastatic lymph nodes, and peritoneal metastases. Ultimately, this provides a more informative map of the mesentery displaying lymphatics and blood flow. The technique is economical and easy to use by the surgeon intraoperatively. ICG lymphangiography has the potential to aid the surgeon to ensure complete lymphadenectomy is performed in cancer resections.

Clinical application of indocyanine green fluorescence imaging in laparoscopic lymph node dissection for intrahepatic cholangiocarcinoma: A pilot study (with video)

BACKGROUND

Intrahepatic cholangiocarcinoma is a highly lethal malignancy characterized by lymph node metastasis. This study aimed to evaluate the efficacy of indocyanine green fluorescence for visualization of lymphatic drainage and to assess its clinical application during laparoscopic lymph node dissection for intrahepatic cholangiocarcinoma.

METHODS

All patients with intrahepatic cholangiocarcinoma who underwent laparoscopic left hepatectomy and lymph node dissection between October 2018 and January 2021 were reviewed. The patients were assigned to the indocyanine green group or non-intrahepatic cholangiocarcinoma group based on the staining technique used.

RESULTS

Of 38 patients with left hemiliver intrahepatic cholangiocarcinoma, 20 underwent intrahepatic cholangiocarcinoma tracer-guided laparoscopic radical left hepatectomy; 12 procedures were successful (indocyanine green group). During the same period, 18 patients were treated with traditional laparoscopic resection (control group). Their intraoperative factors were comparable and there were no differences in the incidence or severity of their postoperative complications 30 days after surgery (P > .05). In the indocyanine green group, more lymph nodes were harvested (mean [range]: 7.0 [6.0-8.0] vs 3.5 [3.0-5.0], P < .001) and the proportion of confirmed pathologic lymph nodes was higher (75.0%, 66.7%-87.5% vs 40%, 33.3%-50.0%, P < .001). ICG staining was observed in all (12/12, 100%) patients in the intrahepatic cholangiocarcinoma group at stations 8 and 12, and 9 (9/12, 75%) and 10 (11/12, 91.7%) patients at Stations 13 and 7, respectively.

CONCLUSION

The indocyanine green fluorescence imaging system is feasible, safe, and effective for tracing lymph nodes. It can be used to identify regional lymphatic drainage patterns and help define the scope of lymph node dissection in patients with intrahepatic cholangiocarcinoma.

Nectin-4-targeted immunoSPECT/CT imaging and photothermal therapy of triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is more prone to distant metastasis and visceral recurrence in comparison to other breast cancer subtypes, and is related to dismal prognosis. Nevertheless, TNBC has an undesirable response to targeted therapies. Therefore, to tackle the huge challenges in the diagnosis and treatment of TNBC, Nectin-4 was selected as a theranostic target because it was recently found to be highly expressed in TNBC. We developed anti-Nectin-4 monoclonal antibody (mAbNectin-4)-based theranostic pair, 99mTc-HYNIC-mAbNectin-4 and mAbNectin-4-ICG. 99mTc-HYNIC-mAbNectin-4 was applied to conduct immuno-single photon emission computed tomography (SPECT) for TNBC diagnosis and classification, and mAbNectin-4-ICG to mediate photothermal therapy (PTT) for relieving TNBC tumor growth.

METHODS

Nectin-4 expression levels of breast cancer cells (MDA-MB-468: TNBC cells; and MCF-7, non-TNBC cells) were proved by western blot, flow cytometry, and immunofluorescence imagning. Cell uptake assays, SPECT imaging, and biodistribution were performed to evaluate Nectin-4 targeting of 99mTc-HYNIC-mAbNectin-4. A photothermal agent (PTA) mAbNectin-4-ICG was generated and characterized. In vitro photothermal therapy (PTT) mediated by mAbNectin-4-ICG was conducted under an 808 nm laser. Fluorescence (FL) imaging was performed for mAbNectin-4-ICG mapping in vivo. In vivo PTT treatment effects on TNBC tumors and corresponding systematic toxicity were evaluated.

RESULTS

Nectin-4 is overexpressed in MDA-MB-468 TNBC cells, which could specifically uptake 99mTc-HYNIC-mAbNectin-4 with high targeting in vitro. The corresponding immunoSPECT imaging demonstrated exceptional performance in TNBC diagnosis and molecular classification. mAbNectin-4-ICG exhibited favourable biocompatibility, photothermal effects, and Nectin-4 targeting. FL imaging mapped biodistribution of mAbNectin-4-ICG with excellent tumor-targeting and retention in vivo. Moreover, mAbNectin-4-ICG-mediated PTT provided advanced TNBC tumor destruction efficiency with low systematic toxicity.

CONCLUSION

mAbNectin-4-based radioimmunoimaging provides visualization tools for the stratification and diagnosis for TNBC, and the corresponding mAbNectin-4-mediated PTT shows a powerful anti-tumor effect. Our findings demonstrate that this Nectin-4 targeting strategy offers a simple theranostic platform for TNBC.

Fluorescent ureterography with indocyanine green in laparoscopic colorectal surgery: A safe method to prevent intraoperative ureteric injury

Intraoperative injuries to the ureter can occur in complicated colorectal and gynaecologic procedures in minimal access surgery. The majority of these go unrecognised at the time of the operation, which can be disastrous to the patient. The routine use of ureteric stents is controversial, with some studies showing that stents only enable detection of ureteric injury but do not prevent it. Fluorescent image-guided surgery with indocyanine green (ICG) to visualise the ureter is a relatively new technique. We report our method of visualisation of the ureter in two patients undergoing laparoscopic anterior resection and Hartmann procedure, respectively. After induction of anaesthesia, retrograde catheterisation of both ureters was performed by the urologist. 2.5 mg ICG was injected into each catheter at the start of the procedure. Both ureters were visualised very well throughout the procedure with no post-operative complications. This technique using ICG adds visual cues to make up for the loss of tactile feedback, making it a safe strategy to prevent intraoperative ureteric injury.

Consensus Conference Statement on the General Use of Near-infrared Fluorescence Imaging and Indocyanine Green Guided Surgery: Results of a Modified Delphi Study

BACKGROUND

In recent decades, the use of near-infrared light and fluorescence-guidance during open and laparoscopic surgery has exponentially expanded across various clinical settings. However, tremendous variability exists in how it is performed.

OBJECTIVE

In this first published survey of international experts on fluorescence-guided surgery, we sought to identify areas of consensus and nonconsensus across 4 areas of practice: fundamentals; patient selection/preparation; technical aspects; and effectiveness and safety.

METHODS

A Delphi survey was conducted among 19 international experts in fluorescence-guided surgery attending a 1-day consensus meeting in Frankfurt, Germany on September 8th, 2019. Using mobile phones, experts were asked to anonymously vote over 2 rounds of voting, with 70% and 80% set as a priori thresholds for consensus and vote robustness, respectively.

RESULTS

Experts from 5 continents reached consensus on 41 of 44 statements, including strong consensus that near-infrared fluorescence-guided surgery is both effective and safe across a broad variety of clinical settings, including the localization of critical anatomical structures like vessels, detection of tumors and sentinel nodes, assessment of tissue perfusion and anastomotic leaks, delineation of segmented organs, and localization of parathyroid glands. Although the minimum and maximum safe effective dose of ICG were felt to be 1 to 2 mg and >10 mg, respectively, there was strong consensus that determining the optimum dose, concentration, route and timing of ICG administration should be an ongoing research focus.

CONCLUSIONS

Although fluorescence imaging was almost unanimously perceived to be both effective and safe across a broad range of clinical settings, considerable further research remains necessary to optimize its use.

Functionalized LbL Film for Localized Delivery of STAT3 siRNA and Oxaliplatin Combination to Treat Colon Cancer

The aim of the study was to develop and evaluate the efficacy of a functionalized layer-by-layer (LbL) assembled film entrapped with oxaliplatin (OX) and signal transducer and activator of transcription 3 (STAT3) siRNA in the localized treatment of colon cancer. The LbL film was prepared by the sequential layering of chitosan (CS) and alginate to attain desired physical and mechanical properties. The film was functionalized by coating folic acid-conjugated CS on one side. On the other side, polycaprolactone was coated as a backing layer to provide directional drug release. OX was entrapped within the layers of the film, while STAT3 siRNA was complexed with CS to form nanoparticles before entrapment in the LbL film. The CS-siRNA nanoparticles were taken up by the colon carcinoma, Caco-2 cells within 3 h and provided concentration-dependent reduction in STAT3 protein expression. The functionalized LbL film (F-LbL film) selectively adhered to the colon cancer tissue in the mice model, whereas the nonfunctionalized film adhered to the normal colon tissue. The combination of OX and STAT3 siRNA provided significantly greater tumor regression, survival rate, and STAT3 protein suppression after localized delivery through oral administration compared with intravenous administration. Taken together, the F-LbL film can selectively bind to colon tumors for localized delivery of drugs to treat colon cancer.

Emerging Technologies for the Detection of Cancer Micrometastasis

The most efficient way to treat tumors is through surgery. However, many cancer patients have a poor prognosis even when they undergo radical excision at an early stage. Micrometastasis is one of the most critical factors that induced this situation. Undetected micrometastasis can lead to the failure of initial treatment. Therefore, preoperative and intraoperative detection of micrometastasis could have a significant clinical influence on the prognosis and optimal therapy for cancer patients. Additionally, to achieve this goal, researchers have aimed to create more effective detection technologies. Herein, we classify the currently reported micrometastasis detection technologies, introduce some representative samples for each technology, including the limitations, and provide future directions to overcome the limitations.

Indocyanine green fluorescence to ensure perfusion in middle segment-preserving pancreatectomy: a case report

Background

Middle segment-preserving pancreatectomy (MSPP) is an alternative to total pancreatectomy that allows for the preservation of the endocrine and exocrine functions of the pancreas. However, maintaining perfusion to the pancreatic remnant is of critical importance. We describe the first case to our knowledge in which indocyanine green (ICG) fluorescence was used to confirm perfusion to the pancreatic remnant during MSPP.

Case presentation

A 79-year-old man with diabetes mellitus was referred to our hospital for treatment of a pancreatic tumor. Computed tomography revealed a hypovascular mass in the uncus of the pancreas and dilatation of the main pancreatic duct, measuring 13 mm in the tail of the pancreas. He was diagnosed with cancer of the pancreatic uncus via endoscopic ultrasound and fine-needle aspiration revealed a mixed-type intraductal papillary mucinous neoplasm (IPMN), along with high-risk stigmata in the tail of the pancreas. We performed MSPP and the length of the pancreatic remnant was 4.6 cm. The dorsal pancreatic artery was preserved and perfusion to the pancreatic remnant was confirmed by ICG fluorescence. Histopathological examination showed a pancreatic ductal adenocarcinoma in the uncus (pT1cN1M0, pStage 2B) and IPMN in the tail of the pancreas. The postoperative course was complicated by a grade B pancreatic fistula, but this was successfully treated with conservative management. The patient was transferred to a hospital 33 days after surgery. Insulin administration was necessary, but C-peptide was detectable and blood glucose was relatively well-controlled. He did not exhibit any exocrine dysfunction when pancreatic enzyme supplementation was administered.

Conclusion

ICG fluorescence can be used to evaluate perfusion to the pancreatic remnant during MSPP.

Indocyanine green fluorescence angiography after full-thickness bowel resection for rectosigmoid endometriosis: A multicentric experience with quantitative analysis

OBJECTIVE

To evaluate effectiveness and reproducibility of qualitative and quantitative near-infrared indocyanine green (NIR-ICG) analyses as a tool for anastomotic perfusion assessment after full-thickness bowel resection for rectosigmoid endometriosis (RSE).

METHODS

Symptomatic women with RSE undergoing minimally invasive full-thickness surgical excision of RSE and NIR-ICG evaluation from November 2019 to July 2020 were included. Study outcomes were the accuracy of qualitative and quantitative NIR-ICG analyses in predicting bowel fistula and their reproducibility. NIR-ICG predictive accuracy was assessed by calculating sensitivity, specificity, and area under the curve on receiver operating characteristic curves with 95% confidence intervals (CI). NIR-ICG reproducibility was assessed through Cohen's k coefficient to determine interoperator agreement between two observers.

RESULTS

Of 33 patients, 2 (6%) developed bowel fistula. In predicting bowel fistula, qualitative and quantitative NIR-ICG evaluations showed sensitivity of 100% and 100%, specificity of 71% and 93%, and area under the curve of 0.86 (95% CI 0.67-1.00) and 0.96 (95% CI 0-1.00), respectively. Regarding interoperator agreement rate, it was reported as excellent for the qualitative analysis and very good for the quantitative analysis.

CONCLUSION

Qualitative and quantitative NIR-ICG evaluations might be effective and reproducible tools for anastomotic perfusion assessment after discoid or segmental resection for RSE. Quantitative evaluation might be even more effective than qualitative evaluation in predicting bowel fistula.