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 Spectrum^TM 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.

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.

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.

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.

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.

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 10mg was administered intravenously 24 hours before surgery. Real-time intraoperative NIRF visualization was made 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, compared to preoperative MRI. PLC, liver metastases, and additional lesions were then resected according to oncological principles. Of all resected specimens the resection margins were analyzed with the fluorescence imaging system for ICG positive spots right 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 laparoscopically. Additional ICG positive lesions were detected in 23 (35.4%) patients of which nine (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 a ICG positive resection margin with a 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 were 95.2% and 88.4%, respectively. Conclusion The here presented study provides significant evidence that ICG NIRF guidance helps to identify R0 resection intraoperatively. This offers a true potential to verify radical resection and improve patients´ outcome. Furthermore, implementation of NIRF guided imaging in liver tumor surgery allows to detect a considerable amount of additional malignant lesions.