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Intraoperative identification of cancerous tissue is fundamental during oncological surgical or endoscopic procedures. This relies on visual assessment supported by histopathological evaluation, implying a longer operative time. Hyperspectral imaging (HSI), a contrast-free and contactless imaging technology, provides spatially resolved spectroscopic analysis, with the potential to differentiate tissue at a cellular level. However, HSI produces "big data", which is impossible to directly interpret by clinicians. We hypothesize that advanced machine learning algorithms (convolutional neural networks-CNNs) can accurately detect colorectal cancer in HSI data.In 34 patients undergoing colorectal resections for cancer, immediately after extraction, the specimen was opened, the tumor-bearing section was exposed and imaged using HSI. Cancer and normal mucosa were categorized from histopathology. A state-of-the-art CNN was developed to automatically detect regions of colorectal cancer in a hyperspectral image. Accuracy was validated with three levels of cross-validation (twofold, fivefold, and 15-fold).32 patients had colorectal adenocarcinomas confirmed by histopathology (9 left, 11 right, 4 transverse colon, and 9 rectum). 6 patients had a local initial stage (T1-2) and 26 had a local advanced stage (T3-4). The cancer detection performance of the CNN using 15-fold cross-validation showed high sensitivity and specificity (87% and 90%, respectively) and a ROC-AUC score of 0.95 (considered outstanding). In the T1-2 group, the sensitivity and specificity were 89% and 90%, respectively, and in the T3-4 group, the sensitivity and specificity were 81% and 93%, respectively.Automatic colorectal cancer detection on fresh specimens using HSI, using a properly trained CNN is feasible and accurate, even with small datasets, regardless of the local tumor extension. In the near future, this approach may become a useful intraoperative tool during oncological endoscopic and surgical procedures, and may result in precise and non-destructive optical biopsies to support objective and consistent tumor-free resection margins.

Cholecystocholedocholithiasis (CCL) occurs in up to 18% of patients undergoing laparoscopic cholecystectomy (LC). The two-stage treatment using endoscopic retrograde cholangiopancreatography (ERCP) followed by LC is the treatment of choice for CCL. However, only 10 to 60% of patients have common bile duct (CBD) stones at the time of ERCP, thus exposing patients to unnecessary ERCPs, causing 3 to 15% of post-interventional pancreatitis. One-stage laparoscopic-endoscopic rendezvous (LERV) is an alternative for the treatment of CCL. Given the selective top-to-bottom CBD cannulation, LERV reduces the risk of pancreatitis and failed CBD cannulation. Additionally, LERV is performed exclusively in patients presenting CBD stones at intraoperative cholangiography, avoiding unnecessary ERCPs. Despite its advantages, considering the logistical burden of coordinating different specialties, LERV is performed in few centers. Here, we present the largest retrospective series of LERVs performed at our department, analyzing elective and emergency procedures.All consecutive patients undergoing LERV for CCL between January 2014 and December 2021 were included. LERV success rate, operative time, biliary outflow restoration rate, postoperative complications (POC), length of hospital stay (LOS), and recurrences were analyzed.181 patients were included (61 elective LERVs, 120 emergency LERVs). We reported a 100% LERV success rate, a 97.79% biliary outflow restoration rate, a 0% conversion rate, a mean intraoperative time of 120.17 ± 31.35 min, and LOS of 4.00 ± 2.82 days. POC included 7 Clavien-Dindo type 1, 11 type 2, and 3 type 3 cases. Seven patients presented with CBD stone recurrence: 2 within 30 days after discharge, 3 within 6 months after discharge, and 2 patients at 1 year. No statistically significant difference was found between elective and emergency patients.LERV is safe, representing a valid option even in emergency settings, thus enabling the management of CCL within a single procedure, consequently sparing additional anesthesia and decreasing post-ERCP complications.

Endoscopic sleeve gastroplasty (ESG) is a promising bariatric endoluminal procedure. Restriction and shortening of the stomach are obtained by means of non-resorbable full-thickness sutures, thus inducing the formation of several endoluminal pouches in which food can stagnate. The effect of ESG on the upper gastrointestinal tract has never been investigated.This study objectively evaluates endoscopic macroscopic and histopathologic changes within 12-month follow-up (FU) in patients who underwent ESG.Retrospective study on a prospective database of patients who underwent ESG at our tertiary referral center between October 2016 and March 2019.All consecutive patients undergoing upper endoscopy (EGD) preoperatively and 6 and 12 months after ESG were included. The upper gastrointestinal tract was evaluated for mucosal abnormalities and biopsies were systematically taken.Eighty-six patients were included. EGD results were as follows: esophagitis decreased from 14% preoperatively to 3.6% and 1.2% at 6- and 12-month FU, respectively (P = .001); 19.8% of patients presented preoperatively a type I hiatal hernia4 cm and showed no size increment or de novo hiatal hernia at 6- and 12-months. The rate of preoperative hyperemic (23.2%) and erosive (3.5%) gastropathy decreased to 9.5% and 1.2% at 6 months and 17.4% and 1.2% at 12 months, respectively. Gastric ulcer (4.7%), duodenal hyperemic mucosa (1.2%) and duodenal micro-ulcerations (2.3%) detected preoperatively were not present at 6- and 12-month EGD. The rate of histopathological disease, which was 68.1% preoperatively, dropped to 29.2% at 12 months, chronic gastritis decreased from 40.3% to 26.4%, acute gastritis from 9.7% to 0%, and acute inflammation on chronic gastritis from 18% to 2.8% (P.001).ESG is a safe procedure that does not promote the new onset of macroscopic and histopathologic abnormalities within 1-year follow-up.

Zusammenfassung Hintergrund Die Fluoreszenz-Angiografie (FA) mit Indocyanin-Grün (ICG) und das Hyperspektral-Imaging (HSI) sind neue intraoperative Visualisierungsmöglichkeiten in der Abdominal-, Gefäß- und Transplantationschirurgie. Ziel ist es, damit die postoperative Morbidität und Mortalität im Sinne der Präzisionschirurgie und Patientensicherheit zu reduzieren. In diesem Artikel werden aktuelle Daten und das zukünftige innovative Potenzial der Echtzeit-Bildgebungsmodalitäten hervorgehoben. Methoden Das Prinzip der neuen „Imaging“-Verfahren und deren klinische Anwendungen werden aufgearbeitet mit Blick auf Anastomoseninsuffizienzen, die die folgenschwersten Komplikationen in der gastrointestinalen Chirurgie nach onkologischen Resektionen darstellen. Ergebnisse Während die FA die Gabe eines Fluoreszenzfarbstoffs erfordert, ist HSI völlig kontaktfrei und nichtinvasiv. Beide Methoden können in „Real-Time“-Applikation physiologische Gewebeeigenschaften, zudem die FA auch dynamische Phänomene, erfassen. Die Verfahren dauern nur wenige Sekunden und stören den operativen Ablauf nicht wesentlich. Sie sind hinsichtlich ihrer Aussagekraft für eine mögliche Änderung der operativen Strategie als komplementär zu betrachten. Unsere eigenen Weiterentwicklungen der Modalitäten liegen insbesondere im Bereich der Datenvisualisierung sowie der automatischen Datenanalyse unter Einsatz der künstlichen Intelligenz (KI) und der Miniaturisierung der bisherigen Geräte für einen zukünftigen Einsatz in der Endoskopie, der minimalinvasiven und der roboterassistierten Chirurgie. Schlussfolgerung Insgesamt ist die Zahl der Studien im Forschungsfeld der intraoperativen Bildgebung zurzeit noch sehr limitiert. Ob diese neue Art der Präzisionschirurgie im „Hightech“-OP mit der Kombination aus HSI, FA und Robotik zu einer verbesserten Patientensicherheit durch Minimierung der postoperativen Morbidität und Mortalität führt, muss in weiterführenden multizentrischen Studien evaluiert werden.

Introduction/objective Gastric conduit (GC) is used for reconstruction after esophagectomy. Anastomotic leakage (AL) incidence remains high, given the extensive disruption of the gastric circulation. Currently, there is no reliable method to intraoperatively quantify gastric perfusion. Hyperspectral imaging (HSI) has shown its potential to quantify serosal StO2. Confocal laser endomicroscopy (CLE) allows for automatic mucosal microcirculation quantification as functional capillary density area (FCD-A). The aim of this study was to quantify serosal and mucosal GC’s microperfusion using HSI and CLE. Local capillary lactate (LCL) served as biomarker. Methods GC was formed in 5 pigs and serosal StO2% was quantified at 3 regions of interest (ROI) using HSI: fundus (ROI-F), greater curvature (ROI-C), and pylorus (ROI-P). After intravenous injection of sodium-fluorescein (0.5 g), CLE-based mucosal microperfusion was assessed at the corresponding ROIs, and LCLs were quantified via a lactate analyzer. Results StO2 and FCD-A at ROI-F (41 ± 10.6%, 3.3 ± 3.8, respectively) were significantly lower than ROI-C (68.2 ± 6.7%, p value: 0.005; 18.4 ± 7, p value: 0.01, respectively) and ROI-P (72 ± 10.4%, p value: 0.005; 15.7 ± 3.2 p value: 0.001). LCL value at ROI-F (9.6 ± 4.7 mmol/L) was significantly higher than at ROI-C (2.6 ± 1.2 mmol/L, p value: 0.04) and ROI-P (2.6 ± 1.3 mmol/L, p value: 0.04). No statistically significant difference was found in all metrics between ROI-C and ROI-P. StO2 correlated with FCD-A (Pearson’s r = 0.67). The LCL correlated negatively with both FCD-A (Spearman’s r = − 0.74) and StO2 (Spearman’s r = − 0.54). Conclusions GC formation causes a drop in serosal and mucosal fundic perfusion. HSI and CLE correlate well and might become useful intraoperative tools.

Colorectal surgery has benefited from advances in precision medicine such as total mesorectal resection, and recently, mesocolon resection, fluorescent perfusion imaging, and fluorescent node mapping. However, these advances fail to address the variable quality of mesocolon dissection and the directed extent of vascular dissection (including high ligation) or pre-resection anastomotic perfusion mapping, thereby impacting anastomotic leaks. We propose a new paradigm of precision image-directed colorectal surgery involving 3D preoperative resection modeling and intraoperative fluoroscopic and fluorescence vascular imaging which better defines optimal dissection planes and vascular vs. anatomy-based resection lines according to our hypothesis. Six pigs had preoperative CT with vascular 3D reconstruction allowing for the preoperative planning of vascular-based dissection. Laparoscopic surgery was performed in a hybrid operating room (OR). Superselective arterial catheterization was performed in branches of the superior mesenteric artery (SMA) or the inferior mesenteric artery (IMA). Intraoperative boluses of 0.1 mg/kg or a continuous infusion of indocyanine green (ICG) (0.01 mg/mL) were administered to guide fluorescent-based sigmoid and ileocecal resections. Fluorescence was assessed using proprietary software at several regions of interest (ROI) in the right and left colon. The approach was feasible and safe. Selective catheterization took an average of 43 min. Both bolus and continuous perfusion clearly marked pre-identified vessels (arteries/veins) and the target colon segment, facilitating precise resections based on the visible vascular anatomy. Quantitative software analysis indicated the optimal resection margin for each ROI. Intra-arterial fluorescent mapping allows visualization of major vascular structures and segmental colonic perfusion. This may help to prevent any inadvertent injury to major vascular structures and to precisely determine perfusion-based resection planes and margins. This could enable tailoring of the amount of colon resected, ensure good anastomotic perfusion, and improve oncological outcomes.

Background Intraoperative localization of endoluminal lesions is can be difficult during laparoscopy. Preoperative endoscopic marking is therefore necessary. Current methods include submucosal tattooing using visible dyes, which in case of transmural injection can impair surgical dissection. Tattooing using indocyanine green (ICG) coupled to intraoperative near-infrared (NIR) laparoscopy has been described. ICG is only visible under NIR-light, therefore, it doesn’t impair the surgical workflow under white light even if there is spillage. However, ICG tattoos have rapid diffusion and short longevity. We propose fluorescent over-the-scope clips (FOSC), using a novel biocompatible fluorescent paint, as durable lesion marking. Methods In six pigs, gastric and colonic endoscopic tattoos using 0.05 mg/mL of ICG and markings using the fluorescent OSC were performed (T0). Simultaneously, NIR laparoscopy was executed. Follow-up laparoscopies were conducted at postoperative day (POD) 4–6 (T1) and POD 11–12 (T2). During laparoscopy, fluorescence intensity was assessed. In one human cadaver, FOSC was used to mark a site on the stomach and on the sigmoid colon, respectively. Intraoperative detection during NIR laparoscopy was assessed. Results Gastric and colonic ICG tattooing and OSC markings were easily visible using NIR laparoscopy on T0. All FOSC were visible at T1 and T2 in both stomach and colon, whereas the ICG tattooing at T1 was only visible in the stomach of 2 animals and in the colon of 3 animals. At T2, tattoos were not visible in any animal. FOSC were still visible in both stomach and colon of the human cadaver at 10 days. Conclusion Endoscopic marking using FOSC can be an efficient and durable alternative to standard methods.

Anatomical liver resection (ALR) is the preferred oncological approach for the treatment of primary liver malignancies, such as hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The demarcation line (DL) is formed by means of selective vascular occlusion and is used by surgeons to guide ALR. Emerging intraoperative technologies are playing a major role to enhance the surgeon’s vision and ensure a precise oncologic surgery. In this article, a brief overview of modalities to assess the DL during ALRs is presented, from the established conventional techniques to future perspectives.

Background: An accurate and reliable localization of endoluminal gastrointestinal (GI) lesions is crucial, particularly during minimally invasive surgery. As an extreme consequence, a misdetected GI lesion can lead to the resection of the wrong segment, especially in colorectal surgery. A preoperative endoscopic marking is recommended in case of GI lesions, which are expected to be difficult to detect from the serosal side. In clinical practice, three preoperative endoscopic marking methods are currently used: India ink, SPOT™, and endoclips with intraoperative fluoroscopy. All of them have substantial limitations. This has encouraged research on alternative solutions. Methods: In the current systematic review, animal and clinical studies about alternative preoperative endoscopic marking methods of GI lesions were analyzed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results: Thirty studies were found using PubMed/MEDLINE, EMBASE/Ovid, and the Cochrane Library for the qualitative analysis. Conclusion: Although several smart solutions have been proposed and tested successfully, all of them seem to have a substantial drawback related either to scarce stability on the marking site or potential spreading on the bowel wall or diffusion into the surgical planes.

Aim Transanal total mesorectal excision is a promising novel sphincter-saving procedure for low rectal cancer. However, the transanal bottom-up dissection is associated with increased rates of iatrogenic urethral injuries. Near-infrared fluorescence (NIRF) imaging, given its deeper tissue penetration, has been explored in a limited number of studies for enhanced intra-operative urethral visualization. In this study, we explored the feasibility of a novel, ultrabright, biocompatible fluorescent polymer to coat urinary catheters for the purpose of intra-operative urethral visualization. Methods In an ex vivo experiment, using a near-infrared laparoscope, the fluorescent signal of a coated catheter (near-infrared coating of equipment, NICE) was qualitatively and quantitatively compared to the signal of indocyanine green (ICG)/Instillagel® mixtures and ICG-filled catheters at several concentrations. Also, in three male human torsos, using fluorescent urinary catheters, NIRF-guided perineal dissections and a transanal total mesorectal excision were performed. Intra-operative NIRF-based urethral visualization was performed systematically. Results During the qualitative and quantitative fluorescence signal assessment, NICE-coated catheters were clearly superior to the ICG-based solutions. In the cadaveric experiments, enhanced urethral visualization was possible even at early stages of dissection, when the organ was covered by several tissue layers. Conclusions NICE-coated catheters represent a promising potential to allow for NIRF-based intra-operative urethral visualization.

Background Thyroidectomy is one of the most commonly performed surgical procedures. The region of the neck has a very complex structural organization. It would be beneficial to introduce a tool that can assist the surgeon in tissue discrimination during the procedure. One such solution is the noninvasive and contactless technique, called hyperspectral imaging (HSI). Methods To interpret the HSI data, we implemented a supervised classification method to automatically discriminate the parathyroid, the thyroid, and the recurrent laryngeal nerve from surrounding tissue(muscle, skin) and materials (instruments, gauze). A leave-one-patient-out cross-validation was performed. Results The best performance was obtained using support vector machine (SVM) with a classification and visualization in less than 1.4 seconds. A mean patient accuracy of 68% ± 23% was obtained for all tissues and material types. Conclusions The proposed method showed promising results and have to be confirmed on a larger cohort of patient data.

MRI is the reference for the diagnosis of arterial cerebral ischemia, but its role in acute mesenteric ischemia (AMI) is poorly known.To assess MRI detection of early ischemic bowel lesions in a porcine model of arterial AMI.Prospective/cohort.Porcine model of arterial AMI obtained by embolization of the superior mesenteric artery (seven pigs).A 5-T. T1 gradient-echo-weighted-imaging (WI), half-Fourier-acquisition-single-shot-turbo-spin-echo, T2 turbo-spin-echo, true-fast-imaging-with-steady-precession (True-FISP), diffusion-weighted-echo-planar (DWI).T1-WI, T2-WI, and DWI were performed before and continuously after embolization for 6 hours. The signal intensity (SI) of the ischemic bowel was assessed visually and quantitatively on all sequences. The apparent diffusion coefficient (ADC) was assessed.Paired Student's t-test or Mann-Whitney U-test, significance at P 0.05.One pig died from non-AMI-related causes. The remaining pigs underwent a median 5 h53 (range 1 h24-6 h01) of ischemia. Visually, the ischemic bowel showed signal hyperintensity on DWI-b800 after a median 85 (57-276) minutes compared to the nonischemic bowel. DWI-b800 SI significantly increased after 2 hours (+19%) and the ADC significant decrease within the first hour (-31%). The ischemic bowel was hyperintense on precontrast T1-WI after a median 87 (70-171) minutes with no significant quantitative changes over time (P = 0.46-0.93). The ischemic bowel was hyperintense on T2-WI in three pigs with a significant SI increase on True-FISP after 1 and 2 hours.Changes in SI and ADC can be seen early after the onset of arterial AMI with DWI. The value of T2-WI appears to be limited.1 TECHNICAL EFFICACY: Stage 2.

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.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 (StOAL occurred in one patient who underwent neoadjuvant radiochemotherapy and ultralow anterior resection for rectal cancer. HSI assessment was feasible in all patients, and StOHSI 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.

Simple Summary Good oxygenation of both bowel ends is an important prerequisite to promote anastomotic healing after colorectal resections. Bowel oxygenation is usually assessed clinically. Hyperspectral imaging is a contactless and contrast-free tool that allows quantifying tissue oxygen intraoperatively. In this study, the results of 105 colorectal resections with hyperspectral imaging are reported. Abstract Background: A perfusion deficit is a well-defined and intraoperatively influenceable cause of anastomotic leak (AL). Current intraoperative perfusion assessment methods do not provide objective and quantitative results. In this study, the ability of hyperspectral imaging (HSI) to quantify tissue oxygenation intraoperatively was assessed. Methods: 115 patients undergoing colorectal resections were included in the final analysis. Before anastomotic formation, the bowel was extracted and the resection line was outlined and imaged using a compact HSI camera, in order to provide instantaneously quantitative perfusion assessment. Results: In 105 patients, a clear demarcation line was visible with HSI one minute after marginal artery transection, reaching a plateau after 3 min. In 58 (55.2%) patients, the clinically determined transection line matched with HSI. In 23 (21.9%) patients, the clinically established resection margin was entirely within the less perfused area. In 24 patients (22.8%), the HSI transection line had an irregular course and crossed the clinically established resection line. In four cases, HSI disclosed a clinically undetected lesion of the marginal artery. Conclusions: Intraoperative HSI is safe, well reproducible, and does not disrupt the surgical workflow. It also quantifies bowel surface perfusion. HSI might become an intraoperative guidance tool, potentially preventing postoperative complications.

Thermal ablation is an acceptable alternative treatment for primary liver cancer, of which laser ablation (LA) is one of the least invasive approaches, especially for tumors in high-risk locations. Precise control of the LA effect is required to safely destroy the tumor. Although temperature imaging techniques provide an indirect measurement of the thermal damage, a degree of uncertainty remains about the treatment effect. Optical techniques are currently emerging as tools to directly assess tissue thermal damage. Among them, hyperspectral imaging (HSI) has shown promising results in image-guided surgery and in the thermal ablation field. The highly informative data provided by HSI, associated with deep learning, enable the implementation of non-invasive prediction models to be used intraoperatively. Here we show a novel paradigm “peak temperature prediction model” (PTPM), convolutional neural network (CNN)-based, trained with HSI and infrared imaging to predict LA-induced damage in the liver. The PTPM demonstrated an optimal agreement with tissue damage classification providing a consistent threshold (50.6 ± 1.5 °C) for the damage margins with high accuracy (~0.90). The high correlation with the histology score (r = 0.9085) and the comparison with the measured peak temperature confirmed that PTPM preserves temperature information accordingly with the histopathological assessment.

Ein prazises Lymphknoten(LK)-Staging ist in der onkologischen Chirurgie unerlasslich. Indocyaningrun(ICG)-gesteuerte Sentinel-Lymphknoten-Navigation mit Nahinfrarotfluoreszenz (NIRF) ist eine relativ neue Technik. Ziel dieses Artikels ist es, den Einfluss von ICG-NIRF auf die Identifikation von LK-Metastasen bei gastrointestinalen Tumoren zu analysieren. Es wurden die Literaturdatenbanken Scopus und PubMed/MEDLINE durchsucht und 20 Studien eingeschlossen. ICG-NIRF-LK-Navigation ermoglicht und verbessert den LK-Nachweis bei gastrointestinalen Tumoren. Die mittleren Detektions‑, Sensitivitats‑, Genauigkeits- und Falsch-negativ-Raten variierten jedoch erheblich. Dies konnte sowohl auf die Heterogenitat der angewandten Techniken als auch auf die geringe Lymphknotenretention von ICG zuruckzufuhren sein. Die Fluoreszenzbildgebung zur Identifikation des Lymphabflusses ist vielversprechend zur Verbesserung der onkologischen Ergebnisse. Dennoch erfordert die Technik Weiterentwicklungen in Bezug auf Hardware, Software und Fluorophore, die derzeit erforscht werden.

Die Hyperspektralbildgebung („HyperSpectral Imaging“ [HSI]) erlaubt quantitative Gewebeanalysen uber die Limitationen des menschlichen Auges hinaus. Somit dient es als neues Diagnostikinstrument der optischen Eigenschaften verschiedener Gewebe. Im Gegensatz zu anderen intraoperativen bildgebenden Methoden ist HSI kontaktlos, nichtinvasiv und bedarf keiner Kontrastmittelapplikation. Die Messungen nehmen nur wenige Sekunden in Anspruch und storen somit die Operationsablaufe unwesentlich. Erste HSI-Anwendungen in der Viszeralchirurgie sind vielversprechend mit dem Potenzial optimierter Ergebnisse. Aktuelle Konzepte, Moglichkeiten und neue Perspektiven der HSI-Technologie sowie deren Limitationen werden in dieser Arbeit diskutiert.

HSI is an optical technology allowing for a real-time, contrast-free snapshot of physiological tissue properties, including oxygenation. Hyperspectral imaging (HSI) has the potential to quantify the gastrointestinal perfusion intraoperatively. This experimental study evaluates the accuracy of HSI, in order to quantify bowel perfusion, and to obtain a superposition of the hyperspectral information onto real-time images. In 6 pigs, 4 ischemic bowel loops were created (A, B, C, D) and imaged at set time points (from 5 to 360 min). A commercially available HSI system provided pseudo-color maps of the perfusion status (StO2, Near-InfraRed perfusion) and the tissue water index. An ad hoc software was developed to superimpose HSI information onto the live video, creating the HYPerspectral-based Enhanced Reality (HYPER). Seven regions of interest (ROIs) were identified in each bowel loop according to StO2 ranges, i.e., vascular (VASC proximal and distal), marginal vascular (MV proximal and distal), marginal ischemic (MI proximal and distal), and ischemic (ISCH). Local capillary lactates (LCL), reactive oxygen species (ROS), and histopathology were measured at the ROIs. A machine-learning-based prediction algorithm of LCL, based on the HSI-StO2%, was trained in the 6 pigs and tested on 5 additional animals. HSI parameters (StO2 and NIR) were congruent with LCL levels, ROS production, and histopathology damage scores at the ROIs discriminated by HYPER. The global mean error of LCL prediction was 1.18 ± 1.35 mmol/L. For StO2 values > 30%, the mean error was 0.3 ± 0.33. HYPER imaging could precisely quantify the overtime perfusion changes in this bowel ischemia model.

Nerves are critical structures that may be difficult to recognize during surgery. Inadvertent nerve injuries can have catastrophic consequences for the patient and lead to life-long pain and a reduced quality of life. Hyperspectral imaging (HSI) is a non-invasive technique combining photography with spectroscopy, allowing non-invasive intraoperative biological tissue property quantification. We show, for the first time, that HSI combined with deep learning allows nerves and other tissue types to be automatically recognized in in vivo hyperspectral images. An animal model was used, and eight anesthetized pigs underwent neck midline incisions, exposing several structures (nerve, artery, vein, muscle, fat, skin). State-of-the-art machine learning models were trained to recognize these tissue types in HSI data. The best model was a convolutional neural network (CNN), achieving an overall average sensitivity of 0.91 and a specificity of 1.0, validated with leave-one-patient-out cross-validation. For the nerve, the CNN achieved an average sensitivity of 0.76 and a specificity of 0.99. In conclusion, HSI combined with a CNN model is suitable for in vivo nerve recognition.

Fluorescence angiography (FA) with indocyanine green (ICG) and hyperspectral imaging (HSI) are novel intraoperative visualization techniques in abdominal, vascular and transplant surgery. With the purpose of precision surgery, and in order to increase patient's safety, these new tools aim at reducing postoperative morbidity and mortality. This review discusses and highlights recent developments and the future potential of real-time imaging modalities.The underlying mechanisms of the novel imaging methods and their clinical impact are displayed in the context of avoiding anastomotic leaks, the most momentous complications in gastrointestinal surgery after oncologic resections.While FA is associated with the admission of a fluorescence agent, HSI is contact-free and non-invasive. Both methods are able to record physiological tissue properties in real-time. Additionally, FA also measures dynamic phenomena. The techniques take a few seconds only and do not hamper the operative workflow considerably. With regard to a potential change of the surgical strategy, FA and HSI have an equal significance. Our own advancements reflect, in particular, the topics of data visualization and automated data analyses together with the implementation of artificial intelligence (AI) and minimalization of the current devices to install them into endoscopes, minimal-invasive and robot-guided surgery.There are a limited number of studies in the field of intraoperative imaging techniques. Whether precision surgery in the "high-tech" OR together with FA, HSI and robotics will result in more secure operative procedures to minimize the postoperative morbidity and mortality will have to be evaluated in future multicenter trials.Die Fluoreszenz-Angiografie (FA) mit Indocyanin-Grün (ICG) und das Hyperspektral-Imaging (HSI) sind neue intraoperative Visualisierungsmöglichkeiten in der Abdominal-, Gefäß- und Transplantationschirurgie. Ziel ist es, damit die postoperative Morbidität und Mortalität im Sinne der Präzisionschirurgie und Patientensicherheit zu reduzieren. In diesem Artikel werden aktuelle Daten und das zukünftige innovative Potenzial der Echtzeit-Bildgebungsmodalitäten hervorgehoben.Das Prinzip der neuen „Imaging“-Verfahren und deren klinische Anwendungen werden aufgearbeitet mit Blick auf Anastomoseninsuffizienzen, die die folgenschwersten Komplikationen in der gastrointestinalen Chirurgie nach onkologischen Resektionen darstellen.Während die FA die Gabe eines Fluoreszenzfarbstoffs erfordert, ist HSI völlig kontaktfrei und nichtinvasiv. Beide Methoden können in „Real-Time“-Applikation physiologische Gewebeeigenschaften, zudem die FA auch dynamische Phänomene, erfassen. Die Verfahren dauern nur wenige Sekunden und stören den operativen Ablauf nicht wesentlich. Sie sind hinsichtlich ihrer Aussagekraft für eine mögliche Änderung der operativen Strategie als komplementär zu betrachten. Unsere eigenen Weiterentwicklungen der Modalitäten liegen insbesondere im Bereich der Datenvisualisierung sowie der automatischen Datenanalyse unter Einsatz der künstlichen Intelligenz (KI) und der Miniaturisierung der bisherigen Geräte für einen zukünftigen Einsatz in der Endoskopie, der minimalinvasiven und der roboterassistierten Chirurgie.Insgesamt ist die Zahl der Studien im Forschungsfeld der intraoperativen Bildgebung zurzeit noch sehr limitiert. Ob diese neue Art der Präzisionschirurgie im „Hightech“-OP mit der Kombination aus HSI, FA und Robotik zu einer verbesserten Patientensicherheit durch Minimierung der postoperativen Morbidität und Mortalität führt, muss in weiterführenden multizentrischen Studien evaluiert werden.

Currently, colorectal cancer (CRC) is mainly identified via a visual assessment during colonoscopy, increasingly used artificial intelligence algorithms, or surgery. Subsequently, CRC is confirmed through a histopathological examination by a pathologist. Hyperspectral imaging (HSI), a non-invasive optical imaging technology, has shown promising results in the medical field. In the current study, we combined HSI with several artificial intelligence algorithms to discriminate CRC. Between July 2019 and May 2020, 54 consecutive patients undergoing colorectal resections for CRC were included. The tumor was imaged from the mucosal side with a hyperspectral camera. The image annotations were classified into three groups (cancer, CA, adenomatous margin around the central tumor, AD, and healthy mucosa, HM). Classification and visualization were performed based on a four-layer perceptron neural network. Based on a neural network, the classification of CA or AD resulted in a sensitivity of 86% and a specificity of 95%, by means of leave-one-patient-out cross-validation. Additionally, significant differences in terms of perfusion parameters (e.g., oxygen saturation) related to tumor staging and neoadjuvant therapy were observed. Hyperspectral imaging combined with automatic classification can be used to differentiate between CRC and healthy mucosa. Additionally, the biological changes induced by chemotherapy to the tissue are detectable with HSI.

Imaging techniques in gastrointestinal surgery are white light endoscopy, and increasingly fluorescence dye imaging (FI) (ICG). Endoluminal ultrasound (US), optical coherence tomography (OCT), confocal microscopy, Raman spectroscopy imaging, near-infrared (NIR) fluorescence, laser speckle contrast imaging (LSCI), narrowband imaging (NBI), and, more recently, photoacoustic imaging (PA) have shown some potential of improving local tissue discrimination and will be introduced. Hyperspectral imaging (HSI) and multispectral imaging (MSI) are relatively new and deliver unique information on a much larger variety of tissue characteristics. This chapter presents the principles, preclinical and clinical applications of HSI/MSI, novel endoscopic systems, and computer-assisted artificial intelligence (AI) tools for analysis of tissue perfusion, oxygenation, water content, identification of risk structures, and tumor margins. Clinical studies and technical improvements are required to support the establishment of HSI in gastrointestinal (GI) surgery. This includes a comparison of HSI with standard methods, integration with robotic systems, further improvements of data analysis tools by artificial intelligence, and clinical approval of the devices.

This work presents the potential of hyperspectral imaging (HSI) to monitor the thermal outcome of laser ablation therapy used for minimally invasive tumor removal. Our main goal is the establishment of indicators of the thermal damage of living tissues, which can be used to assess the effect of the procedure. These indicators rely on the spectral variation of temperature-dependent tissue chromophores, i.e., oxyhemoglobin, deoxyhemoglobin, methemoglobin, and water. Laser treatment was performed at specific temperature thresholds (from 60 to 110 &deg, C) on in-vivo animal liver and was assessed with a hyperspectral camera (500&ndash, 995 nm) during and after the treatment. The indicators were extracted from the hyperspectral images after the following processing steps: the breathing motion compensation and the spectral and spatial filtering, the selection of spectral bands corresponding to specific tissue chromophores, and the analysis of the areas under the curves for each spectral band. Results show that properly combining spectral information related to deoxyhemoglobin, methemoglobin, lipids, and water allows for the segmenting of different zones of the laser-induced thermal damage. This preliminary investigation provides indicators for describing the thermal state of the liver, which can be employed in the future as clinical endpoints of the procedure outcome.

International audience; Rapidly expanding field of image-guided surgery needs new materials for near-infrared imaging with deep tissue penetration. Here, we introduce near-infrared coating of equipment (NICE) for image-guided surgery based on a series of lipophilic cyanine-7.5 dyes with bulky hydrophobic counterions and a biocompatible polymer, poly(methyl methacrylate). The NICE material exhibits superior brightness (15-20-fold higher) and photostability compared to fluorescent coatings based on commonly used indocyanine green (ICG). It can be deposited on different surfaces and devices, such as steel and gold fiducials, silicone and PVC catheters, polymeric surgical sutures and gauzes. Such coated medical devices show excellent stability in air and buffer for 150 days. Accelerated ageing revealed their shelf-life of 3 years. They are also stable in serum-containing media, whereas ICG-based coating shows rapid dye leakage. NICE is compatible with standard sterilization protocols based on ethylene oxide and vapor. Moreover, our coating material is biocompatible, where cultured cells spread effectively without signs of cytotoxicity. Ex vivo studies suggest that NICE on fiducials can be visualized as deep as 0.5 cm, and NICE on catheters enables their visualization inside ureters and esophagus. Finally, NICE on different medical devices has been validated for image-guided surgery in porcine and human cadaver models. Thus, the developed NIR coating material emerges as a powerful tool for a variety of medical applications.

Purpose One relevant aspect for anastomotic leakage in colorectal surgery is blood perfusion of both ends of the anastomosis. The clinical evaluation of this issue is limited, but new methods like fluorescence angiography with indocyanine green or non-invasive and contactless hyperspectral imaging have evolved as objective parameters for perfusion evaluation. Methods In this prospective, non-randomized, open-label and two-arm study, fluorescence angiography and hyperspectral imaging were compared in 32 consecutive patients with each other and with the clinical assessment by the surgeon. After preparation of the bowel and determination of the surgical resection line, the tissue was evaluated with hyperspectral imaging for 5 min before and after cutting the marginal artery and assessed by 6 hyperspectral pictures followed by fluorescence angiography with indocyanine green. Results In 30 of 32 patients, the image data could be evaluated and compared. Both methods provided a comparable borderline between well-perfused and poorly perfused tissue (p = 0.704). In 15 cases, the surgical resection line was shifted to the central position due to the imaging. The border zone was sharper in fluorescence angiography and best assessed 31 s after injection. With hyperspectral imaging, the border zone was visualized wider and with more differences between proximal and distal border. Conclusion Hyperspectral imaging and fluorescence angiography provide similar results in determining the perfusion border. Both methods allow a good and safe visualization of the blood perfusion at the central resection margin to create a well-perfused anastomosis. Trial registration This study was registered at Clinicaltrials.gov (NCT04226781) on January 13, 2020.

Dual emissions at ~700 and 800 nm have been achieved from a single NIR-AZA fluorophore 1 by establishing parameters in which it can exist in either its isolated molecular or aggregated states. Dual near infrared (NIR) fluorescence color lymph node (LN) mapping with 1 was achieved in a large-animal porcine model, with injection site, channels and nodes all detectable at both 700 and 800 nm using a preclinical open camera system. The fluorophore was also compatible with imaging using two clinical instruments for fluorescence guided surgery. Methods: An NIR-AZA fluorophore with hydrophilic and phobic features was synthesised in a straightforward manner and its aggregation properties characterised spectroscopically and by TEM imaging. Toxicity was assessed in a rodent model and dual color fluorescence imaging evaluated by lymph node mapping in a large animal porcine models and in ex-vivo human tissue specimen. Results: Dual color fluorescence imaging has been achieved in the highly complex biomedical scenario of lymph node mapping. Emissions at 700 and 800 nm can be achieved from a single fluorophore by establishing molecular and aggregate forms. Fluorophore was compatible with clinical systems for fluorescence guided surgery and no toxicity was observed in high dosage testing. Conclusion: A new, biomedical compatible form of NIR-dual emission wavelength imaging has been established using a readily accessible fluorophore with significant scope for clinical translation.

Background:Iatrogenic ureteral injury is one of the feared complications during intrapelvic surgery. There are limited data on the use of novel near-infrared fluorescence (NIRF) imaging dyes for the purpose of noninvasive ureteral visualization in robot-assisted laparoscopic surgery (RALS). In this study, we evaluated the feasibility of NIRF imaging of the ureter using the IRDye(R)800BK dye as the fluorescence dye and a robotic platform with Firefly (TM) technology as an imaging system. Materials and Methods:An intravenous dose of 0.15 mg/kg was administered in 3 pigs and NIRF imaging was performed for a total duration of 60 minutes. The intraoperative video recordings were analyzed to determine fluorescence intensities and the target-to-background ratio (TBR). Results:In all included animals, a clear delineation of the ureter was achieved from 5 minutes after dye administration until the end of the study. During this time period, the ureter was clearly distinguishable from its surroundings and no statistical differences in TBR were observed. Conclusion:The IRDye 800BK dye, a novel NIRF dye currently undergoing clinical translation, is a promising contrast agent used for noninvasive ureteral imaging, which has the potential to be valuable during RALS.

Fluorescence-based enhanced reality (FLER) is a computer-based quantification method of fluorescence angiographies to evaluate bowel perfusion. The aim of this prospective trial was to assess the clinical feasibility and to correlate FLER with metabolic markers of perfusion, during colorectal resections. FLER analysis and visualization was performed in 22 patients (diverticulitis n = 17; colorectal cancer n = 5) intra- and extra-abdominally during distal and proximal resection, respectively. The fluorescence signal of indocyanine green (0.2 mg/kg) was captured using a near-infrared camera and computed to create a virtual color-coded cartography. This was overlaid onto the bowel (enhanced reality). It helped to identify regions of interest (ROIs) where samples were subsequently obtained. Resections were performed strictly guided according to clinical decision. On the surgical specimen, samplings were made at different ROIs to measure intestinal lactates (mmol/L) and mitochondria efficiency as acceptor control ratio (ACR). The native (unquantified) fluorescent signal diffused to obvious ischemic areas during the distal appreciation. Proximally, a lower diffusion of ICG was observed. Five anastomotic complications occurred. The expected values of local capillary lactates were correlated with the measured values both proximally (3.62 ± 2.48 expected vs. 3.17 ± 2.8 actual; rho 0.89; p = 0.0006) and distally (4.5 ± 3 expected vs. 4 ± 2.5 actual; rho 0.73; p = 0.0021). FLER values correlated with ACR at the proximal site (rho 0.76; p = 0.04) and at the ischemic zone (rho 0.71; p = 0.01). In complicated cases, lactates at the proximal resection site were higher (5.8 ± 4.5) as opposed to uncomplicated cases (2.45 ± 1.5; p = 0.008). ACR was reduced proximally in complicated (1.3 ± 0.18) vs. uncomplicated cases (1.68 ± 0.3; p = 0.023). FLER allows to image the quantified fluorescence signal in augmented reality and provides a reproducible estimation of bowel perfusion (NCT02626091).

Background: Peripheral arterial disease has high incidence and complication rates. Vessel recanalization represents the main therapy. However, it induces reperfusion injury. Preconditioning with si...

This study evaluated the use of hyperspectral imaging for the determination of the resection margin during colorectal resections instead of clinical macroscopic assessment. The used hyperspectral camera is able to record light spectra from 500 to 1000 nm and provides information about physiologic parameters of the recorded tissue area intraoperatively (e.g., tissue oxygenation and perfusion). We performed an open-label, single-arm, and non-randomized intervention clinical trial to compare clinical assessment and hyperspectral measurement to define the resection margin in 24 patients before and after separation of the marginal artery over 15 min; HSI was performed each minute to assess the parameters mentioned above. The false color images calculated from the hyperspectral data visualized the margin of perfusion in 20 out of 24 patients precisely. In the other four patients, the perfusion difference could be displayed with additional evaluation software. In all cases, there was a deviation between the transection line planed by the surgeon and the border line visualized by HSI (median 1 mm; range − 13 to 13 mm). Tissue perfusion dropped up to 12% within the first 10 mm distal to the border line. Therefore, the resection area was corrected proximally in five cases due to HSI record. The biggest drop in perfusion took place in less than 2 min after devascularization. Determination of the resection margin by HSI provides the surgeon with an objective decision aid for assessment of the best possible perfusion and ideal anastomotic area in colorectal surgery.

Injuries to the biliary tree during surgical, endoscopic or invasive radiological diagnostic or therapeutic procedures involving the pancreas, liver or organs of the upper gastrointestinal tract give rise to the need to develop a method for clear discrimination of biliary anatomy from surrounding tissue. Hyperspectral imaging (HSI) is an emerging optical technique in disease diagnosis and image-guided surgery with inherent advantages of being a non-contact, non-invasive, and non-ionizing technique. HSI can produce quantitative diagnostic information about tissue pathology, morphology, and chemical composition. HSI was applied in human liver transplantation and compared to porcine model operations to assess the capability of discriminating biliary anatomy from surrounding biological tissue. Absorbance spectra measured from bile ducts, gall bladder, and liver show a dependence on tissue composition and bile concentration, with agreement between human and porcine datasets. The bile pigment biliverdin and structural proteins collagen and elastin were identified as contributors to the bile duct and gall bladder absorbance spectra.

Significance: Hyperspectral imaging (HSI) can support intraoperative perfusion assessment, the identification of tissue structures, and the detection of cancerous lesions. The practical use of HSI for minimal-invasive surgery is currently limited, for example, due to long acquisition times, missing video, or large set-ups. Aim: An HSI laparoscope is described and evaluated to address the requirements for clinical use and high-resolution spectral imaging. Approach: Reflectance measurements with reference objects and resected human tissue from 500 to 1000 nm are performed to show the consistency with an approved medical HSI device for open surgery. Varying object distances are investigated, and the signal-to-noise ratio (SNR) is determined for different light sources. Results: The handheld design enables real-time processing and visualization of HSI data during acquisition within 4.6 s. A color video is provided simultaneously and can be augmented with spectral information from push-broom imaging. The reflectance data from the HSI system for open surgery at 50 cm and the HSI laparoscope are consistent for object distances up to 10 cm. A standard rigid laparoscope in combination with a customized LED light source resulted in a mean SNR of 30 to 43 dB (500 to 950 nm). Conclusions: Compact and rapid HSI with a high spatial- and spectral-resolution is feasible in clinical practice. Our work may support future studies on minimally invasive HSI to reduce intra- and postoperative complications.

Post-operative pancreatic fistula is the most dreadful complication of pancreatic resections. Tissue perfusion is a recognized risk factor of fistula in gastrointestinal anastomosis, but has been poorly studied in case of pancreatic surgery. Organ perfusion can be estimated by several intraoperative optical imaging modalities, including exogenous fluorescence imaging with Indocyanine Green (ICG). A limitation of ICG fluorescence angiography is the lack of a quantitative analytic method. Our group has developed and validated a real-time computational imaging analysis of tissue perfusion, based on the slope of the time of fluorescence peak, defined fluorescence-based enhance reality (FLER). This consists in encoding tissue hemodynamics into a virtual perfusion cartography that is superimposed on intraoperative images in real time, in order to provide the perfusion information to surgeons. Another emerging technology is hyperspectral imaging (HSI), which combines a spectrometer and a camera. HSI obtains spectral tissue curves pixel by pixel in a wide wavelength range and can provide absolute values of concentration and/or oxygen saturation of hemoglobin. The aim of this study was to investigate the efficacy of both imaging modalities, FLER and HSI, to estimate pancreatic perfusion. Methods Twelve pigs were involved and randomly assigned to interventional group (n=6) and a control group (n =6). After a median laparotomy the pancreas was fully exposed. In the interventional group, under radiographic guidance, a segmental ischemia of the pancreas was induced by means of coil embolization in small splenic arterial branches, via a femoral artery approach. No ischemia was induced in the control group. HSI images were obtained using the TIVITA camera (Diaspective Vision, Germany). FLER was obtained after injecting 0.2 mg/kg of ICG and image processing using a dedicated software (ER PERFUSION, IRCAD, France). The augmented reality of color-coded images derived from both FLER and HSI were overlapped on the video image. Local capillary lactates (LCL) were sampled in different regions of interests (ROIs) of the pancreas. LCL were correlated to the absolute values provided by the imaging analyses (slope of time-to-peak and StO2, respectively for fluorescence and HSI). Results In all pigs from the interventional group, the segmental ischemic areas were successfully created. The mean slope was slower; the mean StO2 was lower; and mean LCL were lower in the ischemic zone than in the transition and vital zones. The scatter plot between the slope and StO2, the slope and LCL, and StO2 and LCL in all 12 pigs showed statistically significant correlation. In addition, LCL can be predicted from FLER and StO2. The prediction from HSI StO2 (median error: 0.67 mmol/L) is significantly more accurate than FLER (median error: 0.8 mmol/L) (P=0.02). Conclusions FLER and HSI, enable both to precisely quantify and visualize real-time perfusion of the pancreas in this porcine model of pancreas ischemia. HSI showed a greater accuracy in predicting the value of capillary local lactates when compared to quantitative exogenous fluorescence analysis.

Background The use of 3D laparoscopic systems is expanding. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference with the aim of creating evidence-based statements and recommendations for the surgical community. Methods Systematic reviews of the PubMed and Embase libraries were performed to identify evidence on potential benefits of 3D on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by an international surgical and engineering expert panel which were presented and voted at the EAES annual congress, London, May 2018. Results 9967 abstracts were screened with 138 articles included. 18 statements and two recommendations were generated and approved. 3D significantly shortened operative time (mean difference 11 min (8% [95% CI 20.29-1.72], I-2 96%)). A significant reduction in complications was observed when 3D systems were used (RR 0.75, [95 CI% 0.60-0.94], I-2 0%) particularly for cases involving laparoscopic suturing (RR 0.57 [95% CI 0.35-0.90], I-2 0%). In 69 box trainer or simulator studies, 64% concluded trainees were significant faster and 62% performed fewer errors when using 3D. Conclusion We recommend the use of 3D vision in laparoscopy to reduce the operative time (grade of recommendation: low). Future robust clinical research is required to specifically investigate the potential benefit of 3D laparoscopy system on complication rates (grade of recommendation: high).