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.

Standardized digital solution with surgical procedure manager (SPM®)-an opportunity for maximizing patient safety and efficiency in ileostomy reversal?

Background: Standardization and digitalization are getting more and more essential in surgery. Surgical procedure manager (SPM®) is a freestanding computer serving as a digital supporter in the operating room. SPM® navigates step-by-step through surgery by providing a checklist for each individual step. Methods: This was a single center, retrospective study at the Department for General and Visceral Surgery at Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin. Patients who underwent ileostomy reversal without SPM® in the period of January 2017 until December 2017 were compared to patients who were operated with SPM® in the period of June 2018 until July 2020. Explorative analysis and multiple logistic regression were performed. Results: Overall, 214 patients underwent ileostomy reversal: 95 patients without SPM® vs. 119 patients with SPM®. Ileostomy reversal was performed by head of department/attendings in 34.1%, by fellows in 28.5% and by residents in 37.4%; p = 0.91. Postoperative intraabdominal abscess emerged more often in patients without SPM®: ten (10.5%) patients vs. four (3.4%) patients; p = 0.035. Multiple logistic regression showed a risk reduction for intraabdominal abscess {Odds ratio (OR) 0.19 [95% confidence interval (CI) 0.05-0.71]; p = 0.014} and for bowel perforation [OR 0.09 (95% CI 0.01-0.93); p = 0.043] in the group with use of SPM® in ileostomy reversal. Conclusions: SPM® may reduce postoperative complications in ileostomy reversal such as intraabdominal abscess and bowel perforation. SPM® may contribute to patient safety.

The Value of Indocyanine Green Image-Guided Surgery in Patients with Primary Liver Tumors and Liver Metastases.

INTRODUCTION: Successful R0 resection is crucial for the survival of patients with primary liver cancer (PLC) or liver metastases. Up to date, surgical resection lacks a sensitive, real-time intraoperative imaging modality to determine R0 resection. Real-time intraoperative visualization with near-infrared light fluorescence (NIRF) using indocyanine green (ICG) may have the potential to meet this demand. This study evaluates the value of ICG visualization in PLC and liver metastases surgery regarding R0 resection rates. MATERIALS AND METHODS: Patients with PLC or liver metastases were included in this prospective cohort study. ICG 10 mg was administered intravenously 24 h before surgery. Real-time intraoperative NIRF visualization was created with the SpectrumTM fluorescence imaging camera system. First, all liver segments were inspected with the fluorescence imaging system and intraoperative ultrasound for identification of the known tumor, as well as additional lesions, and were compared to preoperative MRI images. PLC, liver metastases, and additional lesions were then resected according to oncological principles. In all resected specimens, the resection margins were analyzed with the fluorescence imaging system for ICG-positive spots immediately after resection. Histology of additional detected lesions, as well as ICG fluorescence compared to histological resection margins, were assessed. RESULTS: Of the 66 included patients, median age was 65.5 years (IQR 58.7-73.9), 27 (40.9%) were female, and 18 (27.3%) were operated on laparoscopically. Additional ICG-positive lesions were detected in 23 (35.4%) patients, of which 9 (29%) were malignant. In patients with no fluorescent signal at the resection margin, R0 rate was 93.9%, R1 rate was 6.1%, and R2 rate was 0% compared to an ICG-positive resection margin with an R0 rate of 64.3%, R1 rate of 21.4%, and R2 rate of 14.3% (p = 0.005). One- and two-year overall survival rates were 95.2% and 88.4%, respectively. CONCLUSION: The presented study provides significant evidence that ICG NIRF guidance helps to identify R0 resection intraoperatively. This offers true potential to verify radical resection and improve patient outcomes. Furthermore, implementation of NIRF-guided imaging in liver tumor surgery allows us to detect a considerable amount of additional malignant lesions.

Muscarinic Acetylcholine Receptor M3 Expression and Survival in Human Colorectal Carcinoma-An Unexpected Correlation to Guide Future Treatment?

Muscarinic acetylcholine receptor M3 (M3R) has repeatedly been shown to be prominently expressed in human colorectal cancer (CRC), playing roles in proliferation and cell invasion. Its therapeutic targetability has been suggested in vitro and in animal models. We aimed to investigate the clinical role of MR3 expression in CRC for human survival. Surgical tissue samples from 754 CRC patients were analyzed for high or low immunohistochemical M3R expression on a clinically annotated tissue microarray (TMA). Immunohistochemical analysis was performed for established immune cell markers (CD8, TIA-1, FOXP3, IL 17, CD16 and OX 40). We used Kaplan-Meier curves to evaluate patients' survival and multivariate Cox regression analysis to evaluate prognostic significance. High M3R expression was associated with increased survival in multivariate (hazard ratio (HR) = 0.52; 95% CI = 0.35-0.78; p = 0.001) analysis, as was TIA-1 expression (HR = 0.99; 95% CI = 0.94-0.99; p = 0.014). Tumors with high M3R expression were significantly more likely to be grade 2 compared to tumors with low M3R expression (85.7% vs. 67.1%, p = 0.002). The 5-year survival analysis showed a trend of a higher survival rate in patients with high M3R expression (46%) than patients with low M3R expression CRC (42%) (p = 0.073). In contrast to previous in vitro and animal model findings, this study demonstrates an increased survival for CRC patients with high M3R expression. This evidence is highly relevant for translation of basic research findings into clinically efficient treatments.

Near-infrared Fluorescence Imaging for Detecting Pancreatic Liver Metastasis in an Orthotopic Athymic Mouse Model.

BACKGROUND/AIM: Evidence of metastatic disease precludes oncological resection of pancreatic cancer. Near-infrared (NIR) fluorescent labels, such as indocyanine green (ICG), assist in the intraoperative detection of occult and micrometastatic liver disease. The present study aimed to analyse the role of NIR fluorescence imaging using ICG for pancreatic liver disease as proof of concept in an orthotopic athymic mouse model. MATERIALS AND METHODS: Pancreatic ductal adenocarcinoma was induced by injecting L3.6pl human pancreatic tumour cells into the pancreatic tail of seven athymic mice. After four weeks of tumour growth, ICG was injected into the tail vein and NIR fluorescence imaging was performed at harvest to determine tumour-to-liver ratios (TLR) using Quest Spectrum® Fluorescence Imaging Platform. RESULTS: Pancreatic tumour growth and liver metastasis could be visually confirmed for all seven animals. None of the hepatic metastases showed any detectable ICG-uptake. ICG-staining failed to visualize the liver metastases or to increase fluorescence intensity of the rim around the hepatic lesions. CONCLUSION: ICG-staining fails to visualize liver metastases induced by L3.6pl pancreatic tumour cells in athymic nude mice by NIR fluorescence imaging. Further studies are necessary to delineate the underlying mechanism for insufficient ICG uptake in these pancreatic liver metastases and for the lack of a fluorescent rim around the liver lesions.

Feasibility of Novel Software-Based Perfusion Indicators for the Ileal J-Pouch-On the Path towards Objective and Quantifiable Intraoperative Perfusion Assessment with Indocyanine Green Near-Infrared Fluorescence.

BACKGROUND: In restorative proctocolectomy with ileal J-pouch, perfusion assessment is vital to prevent complications such as anastomotic leak (AL). Indocyanine green near-infrared fluorescence (ICG-NIRF) is gaining popularity, while its interpretation and relevance remain subjective. This study aimed to evaluate a standardized ICG-NIRF imaging protocol combined with a novel, software-based assessment to detect areas of impaired perfusion and a possible correlation with AL of the pouch. METHODS: In this prospective study, patients undergoing ileal J-pouch for ulcerative colitis at an inflammatory bowel disease (IBD) referral center were included. Intraoperatively, strictly standardized ICG-NIRF visualization was performed and video-recorded. Postoperatively, a specific software was utilized to determine the change in fluorescence intensity per second (i/s) for systematic regions of interest, generating perfusion-time curves and a pixel-to-pixel map. These were analysed in detail and correlated with clinical outcome (primary end point: AL within 30 days; clearly defined and screened for by pouchoscopy). RESULTS: Four out of 18 included patients developed AL of the ileal pouch-anal anastomosis (IPAA). In the AL group, the perfusion curves on the area adjacent to the IPAA (pouch apex) displayed considerably lower ingress/inflow (median = 1.7; range = 8.5; interquartile-range = 3.8 i/s) and egress/outflow (median = -0.1; range = 0.7; interquartile-range = 0.5 i/s) values than in the non-AL group (ingress: median = 4.3; range = 10.3; interquartile-range = 4.0 i/s); egress: median = (-1.1); range = 3.9; interquartile range = 1.0 i/s). This was confirmed by further novel parameters of pouch perfusion (maximum ingress; maximum egress) and pixel-to-pixel analysis. CONCLUSIONS: This study presents the feasibility of a novel methodology to precisely assess pouch perfusion with ICG-NIRF, identifying comparable, quantifiable, and objective parameters to potentially detect perfusion-associated complications in surgery in real-time.

Perfusion Visualization during Ileal J-Pouch Formation-A Proposal for the Standardization of Intraoperative Imaging with Indocyanine Green Near-Infrared Fluorescence and a Postoperative Follow-Up in IBD Surgery.

BACKGROUND: An anastomotic leak (AL) after a restorative proctocolectomy and an ileal J-pouch increases morbidity and the risk of pouch failure. Thus, a perfusion assessment during J-pouch formation is crucial. While indocyanine green near-infrared fluorescence (ICG-NIRF) has shown potential to reduce ALs, its suitability in a restorative proctocolectomy remains unclear. We aimed to develop a standardized approach for investigating ICG-NIRF and ALs in pouch surgery. METHODS: Patients undergoing a restorative proctocolectomy with an ileal J-pouch for ulcerative colitis at an IBD-referral-center were included in a prospective study in which an AL within 30 postoperative days was the primary outcome. Intraoperatively, standardized perfusion visualization with ICG-NIRF was performed and video recorded for postoperative analysis at three time points. Quantitative clinical and technical variables (secondary outcome) were correlated with the primary outcome by descriptive analysis and logistic regression. A novel definition and grading of AL of the J-pouch was applied. A postoperative pouchoscopy was routinely performed to screen for AL. RESULTS: Intraoperative ICG-NIRF-visualization and its postoperative visual analysis in 25 patients did not indicate an AL. The anastomotic site after pouch formation appeared completely fluorescent with a strong fluorescence signal (category 2) in all cases of ALs (4 of 25). Anastomotic site was not changed. ICG-NIRF visualization was reproducible and standardized. Logistic regression identified a two-stage approach vs. a three-stage approach (Odds ratio (OR) = 20.00, 95% confidence interval [CI] = 1.37-580.18, p = 0.029) as a risk factor for ALs. CONCLUSION: We present a standardized, comparable approach of ICG-NIRF visualization in pouch surgery. Our data indicate that the visual interpretation of ICG-NIRF alone may not detect ALs of the pouch in all cases-quantifiable, objective methods of interpretation may be required in the future.

Objective Perfusion Assessment in Gracilis Muscle Interposition-A Novel Software-Based Approach to Indocyanine Green Derived Near-Infrared Fluorescence in Reconstructive Surgery.

BACKGROUND: Gracilis muscle interposition (GMI) is an established treatment option for complex perineal fistulas and reconstruction. The outcome is limited by complications such as necrosis, impaired wound healing and fistula persistence or recurrence. Quantifiable methods of assessing muscle flap perfusion intraoperatively are lacking. This study evaluates a novel and objective software-based assessment of indocyanine green near-infrared fluorescence (ICG-NIRF) in GMI. METHODS: Intraoperative ICG-NIRF visualization data of five patients with inflammatory bowel disease (IBD) undergoing GMI for perineal fistula and reconstruction were analyzed retrospectively. A new software was utilized to generate perfusion curves for the specific regions of interest (ROIs) of each GMI by depicting the fluorescence intensity over time. Additionally, a pixel-to-pixel and perfusion zone analysis were performed. The findings were correlated with the clinical outcome. RESULTS: Four patients underwent GMI without postoperative complications within 3 months. The novel perfusion indicators identified here (shape of the perfusion curve, maximum slope value, distribution and range) indicated adequate perfusion. In one patient, GMI failed. In this case, the perfusion indicators suggested impaired perfusion. CONCLUSIONS: We present a novel, software-based approach for ICG-NIRF perfusion assessment, identifying previously unknown objective indicators of muscle flap perfusion. Ready for intraoperative real-time use, this method has considerable potential to optimize GMI surgery in the future.

The Simultaneous Presence of Isolated Tumour Cells and Bone Marrow Micrometastases in Stage I and II Colon Cancer-Challenging the Theory of a Chronological Pathway of Tumour Cell Dissemination.

BACKGROUND: According to the common tenet, tumour progression is a chronological process starting with lymphatic invasion. In this respect, the meaning of bone marrow micrometastases (BMM) in patients with lymph node negative colon cancer (CC) is unclear. This study examines the relationship of isolated tumour cells (ITC) in sentinel lymph nodes (SLN) and BMM in patients in early CC. METHODS: BM aspirates were taken from both pelvic crests and in vivo SLN mapping was done during open oncologic colon resection in patients with stage I and II CC. Stainings were performed with the pancytokeratin markers A45-B/B3 and AE1/AE3 as well as H&E. The correlation between the occurrence of ITC+ and BMM+ and their effects on survival was examined using Cox regression analysis. RESULTS: In a total of 78 patients with stage I and II CC, 11 patients (14%) were ITC+, 29 patients (37%) BMM+. Of these patients, only two demonstrated simultaneous ITC+ /BMM+. The occurrence of BMM+ was neither associated with ITC+ in standard correlation (kappa = - 0.13 [95% confidence interval [CI] = - 0.4-0.14], p = 0.342) nor univariate (odds ratio [OR] = 0.39, 95%CI:0.07-1.50, p = 0.180) or multivariate (OR = 0.58, 95%CI: 0.09-2.95, p = 0.519) analyses. Combined detection of ITC+ /BMM+ demonstrated the poorest overall (HR = 61.60, 95%CI:17.69-214.52, p = 0.032) and recurrence free survival (HR = 61.60, 95%CI: 17.69-214.5, p = 0.032). CONCLUSIONS: These results indicate that simultaneous and not interdependent presence of very early lymphatic and haematologic tumour spread may be considered as a relevant prognostic risk factor for patients with stage I and II CC, thereby suggesting the possible need to reconsider the common assumptions on tumour spread proposed by the prevalent theory of sequential tumour progression.

The impact of surgical site infection-a cost analysis.

PURPOSE: Surgical site infection (SSI) occurs in up to 25% of patients after elective laparotomy. We aimed to determine the effect of SSI on healthcare costs and patients' quality of life. METHODS: In this post hoc analysis based on the RECIPE trial, we studied a 30-day postoperative outcome of SSI in a single-center, prospective randomized controlled trial comparing subcutaneous wound irrigation with 0.04% polyhexanide to 0.9% saline after elective laparotomy. Total medical costs were analyzed accurately per patient with the tool of our corporate controlling team which is based on diagnosis-related groups in Germany. RESULTS: Between November 2015 and May 2018, 456 patients were recruited. The overall rate of SSI was 28.2%. Overall costs of inpatient treatment were higher in the group with SSI: median 16.685 €; 19.703 USD (IQR 21.638 €; 25.552 USD) vs. median 11.235 €; 13.276 USD (IQR 11.564 €; 13.656 USD); p < 0.001. There was a difference in surgery costs (median 6.664 €; 7.870 USD with SSI vs. median 5.040 €; 5.952 USD without SSI; p = 0.001) and costs on the surgical ward (median 8.404 €; 9.924 USD with SSI vs. median 4.690 €; 5.538 USD without SSI; p < 0.001). Patients with SSI were less satisfied with the cosmetic result (4.3% vs. 16.2%; p < 0.001). Overall costs for patients who were irrigated with saline were median 12.056 €; 14.237 USD vs. median 12.793 €; 15.107 USD in the polyhexanide group (p = 0.52). CONCLUSION: SSI after elective laparotomy increased hospital costs substantially. This is an additional reason why the prevention of SSI is important. Overall costs for intraoperative wound irrigation with saline were comparable with polyhexanide.

Evaluation of the prognostic relevance of the recommended minimum number of lymph nodes in colorectal cancer-a propensity score analysis.

PURPOSE: Nodal status in colorectal cancer (CRC) is an important prognostic factor, and adequate lymph node (LN) staging is crucial. Whether the number of resected and analysed LN has a direct impact on overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) is much discussed. Guidelines request a minimum number of 12 LN to be analysed. Whether that threshold marks a prognostic relevant cut-off remains unknown. METHODS: Patients operated for stage I-III CRC were identified from a prospectively maintained database. The impact of the number of analysed LN on OS, CSS and DFS was assessed using Cox regression and propensity score analysis. RESULTS: Of the 687 patients, 81.8% had ≥ 12 LN resected and analysed. Median LN yield was 17.0 (IQR 13.0-23.0). Resection and analysis of ≥ 12 LN was associated with improved OS (HR = 0.73, 95% CI: 0.56-0.95, p = 0.033), CSS (HR 0.52, 95% CI: 0.31-0.85, p = 0.030) and DFS (HR = 0.73, 95% CI: 0.57-0.95, p = 0.030) in multivariate Cox analysis. After adjusting for biasing factors with propensity score matching, resection of ≥ 12 LN was significantly associated with improved OS (HR = 0.59; 95% CI: 0.43-0.81; p = 0.002), CSS (HR = 0.34; 95% CI: 0.20-0.60; p < 0.001) and DFS (HR = 0.55; 95% CI: 0.41-0.74; p < 0.001) compared to patients with < 12 LN. CONCLUSION: Eliminating biasing factors by a propensity score matching analysis underlines the prognostic importance of the number of analysed LN. The set threshold marks the minimum number of required LN but nevertheless represents a cut-off regarding outcome in stage I-III CRC. This analysis therefore highlights the significance and importance of adherence to surgical oncological standards.

Dual Inhibition of GLUT1 and the ATR/CHK1 Kinase Axis Displays Synergistic Cytotoxicity in KRAS-Mutant Cancer Cells.

The advent of molecularly targeted therapeutic agents has opened a new era in cancer therapy. However, many tumors rely on nondruggable cancer-driving lesions. In addition, long-lasting clinical benefits from single-agent therapies rarely occur, as most of the tumors acquire resistance over time. The identification of targeted combination regimens interfering with signaling through oncogenically rewired pathways provides a promising approach to enhance efficacy of single-agent-targeted treatments. Moreover, combination drug therapies might overcome the emergence of drug resistance. Here, we performed a focused flow cytometry-based drug synergy screen and identified a novel synergistic interaction between GLUT1-mediated glucose transport and the cell-cycle checkpoint kinases ATR and CHK1. Combined inhibition of CHK1/GLUT1 or ATR/GLUT1 robustly induced apoptosis, particularly in RAS-mutant cancer cells. Mechanistically, combined inhibition of ATR/CHK1 and GLUT1 arrested sensitive cells in S-phase and led to the accumulation of genotoxic damage, particularly in S-phase. In vivo, simultaneous inhibition of ATR and GLUT1 significantly reduced tumor volume gain in an autochthonous mouse model of KrasG12D -driven soft tissue sarcoma. Taken together, these findings pave the way for combined inhibition of GLUT1 and ATR/CHK1 as a therapeutic approach for KRAS-driven cancers. SIGNIFICANCE: Dual targeting of the DNA damage response and glucose transport synergistically induces apoptosis in KRAS-mutant cancer, suggesting this combination treatment for clinical validation in KRAS-stratified tumor patients.