The vaginal route for minimally invasive surgery: a practical guide for general surgeons.

INTRODUCTION: Vaginal approaches have become routine in the field of gynecologic surgery, whereas in general surgery vaginal wall transection is an infrequent practice typically reserved for extensive tumor resections. Approximately two decades ago, natural orifice transluminal endoscopic surgery (NOTES) revolutionized conventional boundaries by accessing the peritoneal cavity transorally, transrectally, or transvaginally, enabling general surgery without visible scars. Although transvaginal approaches have been successfully used for various abdominal procedures by general surgeons, a gap remains in comprehensive training to fully exploit the potential of this route. MATERIAL AND METHODS: PubMed, Google Scholar, and Scopus databases were searched to retrieve relevant articles illustrating how general surgeons can adeptly manage vaginal approaches. RESULTS: The article presents a practical framework for general surgeons to execute a complete vaginal approach, addressing the management of vaginal specimen extraction and vaginal cuff closure, even in the absence of an experienced gynecologist. CONCLUSION: The evolution of abdominal surgery is moving towards less invasive techniques, emphasizing the importance of understanding the nuances and challenges associated with the vaginal route. This approach is linked to minimal oncological, sexual, and infective complications, and to the absence of pregnancy-related complications. Such knowledge becomes increasingly crucial, particularly with the renewed demand for transvaginal access in robot-assisted NOTES procedures.

Fertility-sparing uterine displacement for pelvic malignancies: surgical options and radiotherapy dosimetry on a human cadaver.

BACKGROUND: Radio(chemo)therapy is often required in pelvic malignancies (cancer of the anus, rectum, cervix). Direct irradiation adversely affects ovarian and endometrial function, compromising the fertility of women. While ovarian transposition is an established method to move the ovaries away from the radiation field, surgical procedures to displace the uterus are investigational. This study demonstrates the surgical options for uterine displacement in relation to the radiation dose received.  METHODS: The uterine displacement techniques were carried out sequentially in a human female cadaver to demonstrate each procedure step by step and assess the uterine positions with dosimetric CT scans in a hybrid operating room. Two treatment plans (anal and rectal cancer) were simulated on each of the four dosimetric scans (1. anatomical position, 2. uterine suspension of the round ligaments to the abdominal wall 3. ventrofixation of the uterine fundus at the umbilical level, 4. uterine transposition). Treatments were planned on Eclipse® System (Varian Medical Systems®,USA) using Volumetric Modulated Arc Therapy. Data about maximum (Dmax) and mean (Dmean) radiation dose received and the volume receiving 14 Gy (V14Gy) were collected. RESULTS: All procedures were completed without technical complications. In the rectal cancer simulation with delivery of 50 Gy to the tumor, Dmax, Dmean and V14Gy to the uterus were respectively 52,8 Gy, 34,3 Gy and 30,5cc (1), 31,8 Gy, 20,2 Gy and 22.0cc (2), 24,4 Gy, 6,8 Gy and 5,5cc (3), 1,8 Gy, 0,6 Gy and 0,0cc (4). For anal cancer, delivering 64 Gy to the tumor respectively 46,7 Gy, 34,8 Gy and 31,3cc (1), 34,3 Gy, 20,0 Gy and 21,5cc (2), 21,8 Gy, 5,9 Gy and 2,6cc (3), 1,4 Gy, 0,7 Gy and 0,0cc (4). CONCLUSIONS: The feasibility of several uterine displacement procedures was safely demonstrated. Increasing distance to the radiation field requires more complex surgical interventions to minimize radiation exposure. Surgical strategy needs to be tailored to the multidisciplinary treatment plan, and uterine transposition is the most technically complex with the least dose received.

Development of an ontology for laparoscopic transabdominal adrenalectomy via a comprehensive modified Delphi survey and its validation on a multicentric pilot data set for surgical training and future video analysis with machine learning algorithms.

Surgical technique is essential to ensure safe minimally invasive adrenalectomy. Due to the relative rarity of adrenal surgery, it is challenging to ensure adequate exposure in surgical training. Surgical video analysis supports auto-evaluation, expert assessment and could be a target for automatization. The developed ontology was validated by a European expert consensus and is applicable across the surgical techniques encountered in all participating centres, with an exemplary demonstration in bi-centric recordings. Standardization of adrenalectomy video analysis may foster surgical training and enable machine learning training for automated safety alerts.

Challenges in multi-centric generalization: phase and step recognition in Roux-en-Y gastric bypass surgery.

PURPOSE: Most studies on surgical activity recognition utilizing artificial intelligence (AI) have focused mainly on recognizing one type of activity from small and mono-centric surgical video datasets. It remains speculative whether those models would generalize to other centers. METHODS: In this work, we introduce a large multi-centric multi-activity dataset consisting of 140 surgical videos (MultiBypass140) of laparoscopic Roux-en-Y gastric bypass (LRYGB) surgeries performed at two medical centers, i.e., the University Hospital of Strasbourg, France (StrasBypass70) and Inselspital, Bern University Hospital, Switzerland (BernBypass70). The dataset has been fully annotated with phases and steps by two board-certified surgeons. Furthermore, we assess the generalizability and benchmark different deep learning models for the task of phase and step recognition in 7 experimental studies: (1) Training and evaluation on BernBypass70; (2) Training and evaluation on StrasBypass70; (3) Training and evaluation on the joint MultiBypass140 dataset; (4) Training on BernBypass70, evaluation on StrasBypass70; (5) Training on StrasBypass70, evaluation on BernBypass70; Training on MultiBypass140, (6) evaluation on BernBypass70 and (7) evaluation on StrasBypass70. RESULTS: The model's performance is markedly influenced by the training data. The worst results were obtained in experiments (4) and (5) confirming the limited generalization capabilities of models trained on mono-centric data. The use of multi-centric training data, experiments (6) and (7), improves the generalization capabilities of the models, bringing them beyond the level of independent mono-centric training and validation (experiments (1) and (2)). CONCLUSION: MultiBypass140 shows considerable variation in surgical technique and workflow of LRYGB procedures between centers. Therefore, generalization experiments demonstrate a remarkable difference in model performance. These results highlight the importance of multi-centric datasets for AI model generalization to account for variance in surgical technique and workflows. The dataset and code are publicly available at https://github.com/CAMMA-public/MultiBypass140.

The Humanitarian Impact of Telesurgery and Remote Surgery in Global Medicine.

Telesurgery is a natural evolution of robotic surgery and has potential to address health care deficiencies in underserved areas of the globe. The same expert can reach more patients on the same day via telesurgery, and emergency procedures for neurovascular and cardiac events could be performed at the appropriate time, reducing deaths and disabilities.

Robotic assisted versus laparoscopic surgery for deep endometriosis: a meta-analysis of current evidence.

Endometriosis is a benign inflammatory onco-mimetic disease affecting 10-15% of women in the world. When it is refractory to medical treatments, surgery may be required. Usually, laparoscopy is the preferred approach, but robotic surgery has gained popularity in the last 15 years. This study aims to evaluate the safety and efficacy of robotic-assisted laparoscopic surgery (RAS) versus conventional laparoscopic surgery (LPS) in the treatment of endometriosis. This study adheres to PRISMA guidelines and is registered with PROSPERO. Studies reporting perioperative data comparing RAS and LPS surgery in patients with endometriosis querying PubMed, Google Scholar and ClinicalTrials.gov were included in the analysis. The Quality Assessment of Diagnostic Accuracy Studies 2 tool (QUADAS-2) was used for the quality assessment of the selected articles. Fourteen studies were identified, including 2709 patients with endometriosis stage I-IV for the meta-analysis. There were no significant differences between RAS and LPS in terms of intraoperative and postoperative complications, conversion rate and estimated blood loss. However, patients in the RAS group have a longer operative time (p < 0.0001) and longer hospital stay (p = 0.020) than those in the laparoscopic group. Robotic surgery is not inferior to laparoscopy in patients with endometriosis in terms of surgical outcomes; however, RAS requires longer operative times and longer hospital stay. The benefits of robotic surgery should be sought in the easiest potential integration of robotic platforms with new technologies. Prospective studies comparing laparoscopy to the new robotic systems are desirable for greater robustness of scientific evidence.

Obesity paradox: is a high body mass index positively influencing survival outcomes in gynecological cancers? A systematic review and meta-analysis.

OBJECTIVE: Obesity represents an exponentially growing preventable disease leading to different health complications, particularly when associated with cancer. In recent years, however, an 'obesity paradox' has been hypothesized where obese individuals affected by cancer counterintuitively show better survival rates. The aim of this systematic review and meta-analysis is to assess whether the prognosis in gynecological malignancies is positively influenced by obesity. METHODS: This study adheres to PRISMA guidelines and is registered with PROSPERO. Studies reporting the impact of a body mass index (BMI) of >30 kg/m2 compared with <30 kg/m2 in patients with gynecological cancers listed in PubMed, Google Scholar and ClinicalTrials.gov were included in the analysis. The Quality Assessment of Diagnostic Accuracy Studies 2 tool (QUADAS-2) was used for quality assessment of the selected articles. RESULTS: Twenty-one studies were identified for the meta-analysis, including 14 108 patients with cervical, ovarian, or endometrial cancer. There was no benefit in 5-year overall survival for obese patients compared with non-obese patients (OR 1.2, 95% CI 1.00 to 1.44, p=0.05; I2=71%). When pooling for cancer sub-groups, there were no statistically significant differences in 5-year overall survival in patients with cervical cancer and 5-year overall survival and progression-free survival in patients with ovarian cancer. For obese women diagnosed with endometrial cancer, a significant decrease of 44% in 5-year overall survival (p=0.01) was found, with no significant difference in 5-year disease-free survival (p=0.78). CONCLUSION: According to the results of the present meta-analysis, a BMI of ≥30 kg/m2 does not have a positive prognostic effect on survival compared with a BMI of <30 kg/m2 in women diagnosed with gynecological cancers. The existence of the 'obesity paradox' in other fields, however, suggests the importance of further investigations with prospective studies.

Ultrasound-guided robotic surgical procedures: a systematic review.

INTRODUCTION: Ultrasound has been nicknamed "the surgeon's stethoscope". The advantages of laparoscopic ultrasound beyond a substitute for the sense of touch are considerable, especially for robotic surgery. Being able to see through parenchyma and into vascular structures enables to avoid unnecessary dissection by providing a thorough assessment at every stage without the need for contrast media or ionising radiation. The limitations of restricted angulation and access within the abdominal cavity during laparoscopy can be overcome by robotic handling of miniaturised ultrasound probes and the use of various and specific frequencies will meet tissue- and organ-specific characteristics. The aim of this systematic review was to assess the reported applications of intraoperative ultrasound-guided robotic surgery and to outline future perspectives. METHODS: The study adhered to the PRISMA guidelines. PubMed, Google Scholar, ScienceDirect and ClinicalTrials.gov were searched up to October 2023. Manuscripts reporting data on ultrasound-guided robotic procedures were included in the qualitative analysis. RESULTS: 20 studies met the inclusion criteria. The majority (53%) were related to the field of general surgery during liver, pancreas, spleen, gallbladder/bile duct, vascular and rectal surgery. This was followed by other fields of oncological surgery (42%) including urology, lung surgery, and retroperitoneal lymphadenectomy for metastases. Among the studies, ten (53%) focused on locating tumoral lesions and defining resection margins, four (15%) were designed to test the feasibility of robotic ultrasound-guided surgery, while two (10.5%) aimed to compare robotic and laparoscopic ultrasound probes. Additionally two studies (10.5%) evaluated the robotic drop-in probe one (5%) assessed the hepatic tissue consistency and another one (5%) aimed to visualize the blood flow in the splenic artery. CONCLUSION: The advantages of robotic instrumentation, including ergonomics, dexterity, and precision of movements, are of relevance for robotic intraoperative ultrasound (RIOUS). The present systematic review demonstrates the virtue of RIOUS to support surgeons and potentially reduce minimally invasive procedure times.

Preoperative detection of hepatocellular carcinoma's microvascular invasion on CT-scan by machine learning and radiomics: A preliminary analysis.

INTRODUCTION: Microvascular invasion (MVI) is the main risk factor for overall mortality and recurrence after surgery for hepatocellular carcinoma (HCC).The aim was to train machine-learning models to predict MVI on preoperative CT scan. METHODS: 3-phases CT scans were retrospectively collected among 4 Italian centers. DICOM files were manually segmented to detect the liver and the tumor(s). Radiomics features were extracted from the tumoral, peritumoral and healthy liver areas in each phase. Principal component analysis (PCA) was performed to reduce the dimensions of the dataset. Data were divided between training (70%) and test (30%) sets. Random-Forest (RF), fully connected MLP Artificial neural network (neuralnet) and extreme gradient boosting (XGB) models were fitted to predict MVI. Prediction accuracy was estimated in the test set. RESULTS: Between 2008 and 2022, 218 preoperative CT scans were collected. At the histological specimen, 72(33.02%) patients had MVI. First and second order radiomics features were extracted, obtaining 672 variables. PCA selected 58 dimensions explaining >95% of the variance.In the test set, the XGB model obtained Accuracy = 68.7% (Sens: 38.1%, Spec: 83.7%, PPV: 53.3% and NPV: 73.4%). The neuralnet showed an Accuracy = 50% (Sens: 52.3%, Spec: 48.8%, PPV: 33.3%, NPV: 67.7%). RF was the best performer (Acc = 96.8%, 95%CI: 0.91-0.99, Sens: 95.2%, Spec: 97.6%, PPV: 95.2% and NPV: 97.6%). CONCLUSION: Our model allowed a high prediction accuracy of the presence of MVI at the time of HCC diagnosis. This could lead to change the treatment allocation, the surgical extension and the follow-up strategy for those patients.

Design and preliminary validation of a high-fidelity vascular simulator for robot-assisted manipulation.

The number of robot-assisted minimally invasive surgeries is increasing annually, together with the need for dedicated and effective training. Surgeons need to learn how to address the novel control modalities of surgical instruments and the loss of haptic feedback, which is a common feature of most surgical robots. High-fidelity physical simulation has proved to be a valid training tool, and it might help in fulfilling these learning needs. In this regard, a high-fidelity sensorized simulator of vascular structures was designed, fabricated and preliminarily validated. The main objective of the simulator is to train novices in robotic surgery to correctly perform vascular resection procedures without applying excessive strain to tissues. The vessel simulator was integrated with soft strain sensors to quantify and objectively assess manipulation skills and to provide real-time feedback to the trainee during a training session. Additionally, a portable and user-friendly training task board was produced to replicate anatomical constraints. The simulator was characterized in terms of its mechanical properties, demonstrating its realism with respect to human tissues. Its face, content and construct validity, together with its usability, were assessed by implementing a training scenario with 13 clinicians, and the results were generally positive.

Technical and ethical considerations in telesurgery.

Telesurgery, a cutting-edge field at the intersection of medicine and technology, holds immense promise for enhancing surgical capabilities, extending medical care, and improving patient outcomes. In this scenario, this article explores the landscape of technical and ethical considerations that highlight the advancement and adoption of telesurgery. Network considerations are crucial for ensuring seamless and low-latency communication between remote surgeons and robotic systems, while technical challenges encompass system reliability, latency reduction, and the integration of emerging technologies like artificial intelligence and 5G networks. Therefore, this article also explores the critical role of network infrastructure, highlighting the necessity for low-latency, high-bandwidth, secure and private connections to ensure patient safety and surgical precision. Moreover, ethical considerations in telesurgery include patient consent, data security, and the potential for remote surgical interventions to distance surgeons from their patients. Legal and regulatory frameworks require refinement to accommodate the unique aspects of telesurgery, including liability, licensure, and reimbursement. Our article presents a comprehensive analysis of the current state of telesurgery technology and its potential while critically examining the challenges that must be navigated for its widespread adoption.

Initial experience of robotically assisted endometriosis surgery with a novel robotic system: first case series in a tertiary care center.

Endometriosis is a benign disease requiring surgery if medical treatment can not achieve symptom control. Laparoscopy remains the gold standard and robotic assistance can be beneficial in complex cases. Robot-assisted radical endometriosis excision using the Hugo™ RAS system is a novel approach. The aim of this study is to describe its setting and outcomes in a series of patients in a robotic surgery center. Endometriosis patients who consecutively underwent robot-assisted surgery with the Hugo™ RAS system (Medtronic, USA) were retrospectively enrolled. Disease-specific symptoms before and after surgery, endometriosis stage, as well as perioperative and intraoperative variables including system setup were collected. Early post-operative complications (< 30 days) and follow-up (up to 3 months) were reported. All procedures were completed robotically. Port placement followed the "bridge" configuration with a "compact" docking. The median operative time was 186.5 min (IQR 174-220), the median estimated blood loss 50 ml (IQR 0-100). An intraoperative complication occurred in one patient (6.6%), a bladder laceration with postoperative antibiotic treatment. The median lenght of hospital stay (LOS) was 3 days (IQR 3-4). Surgery achieved a statistically significant decrease in symptoms: mean dysmenorrhea (9.50 ± 0.83 versus 1.7 ± 2.26; p = 0.001), dyschezia (4.27 ± 3.61 versus 2.40 ± 2.92; p = 0.026), dysuria (2.73 ± 3.39 versus 1.87 ± 2.41; p = 0.358), dyspareunia (6.53 ± 3.15 versus 2.93 ± 2.89; p = 0.002) and chronic pelvic pain (8.8 ± 1.20 versus 3.20 ± 2.39; p = 0.001). The integration of this platform in the described configuration was safe with regular perioperative outcomes and significant improvement in symptoms. Prospective comparative studies with a larger cohort and longer follow-up are needed to assess potential advantages over the current gold standard.

How Much Is Enough? A Surgical Perspective on Imaging Modalities to Estimate Function and Volume of the Future Liver Remnant before Hepatic Resection.

Liver resection is the first curative option for most hepatic primary and secondary malignancies. However, post-hepatectomy liver failure (PHLF) still represents a non-negligible postoperative complication, embodying the most frequent cause of hepatic-related mortality. In the absence of a specific treatment, the most effective way to deal with PHLF is its prevention through a careful preoperative assessment of future liver remnant (FLR) volume and function. Apart from the clinical score and classical criteria to define the safe limit of resectability, new imaging modalities have shown their ability to assist surgeons in planning the best operative strategy with a precise estimation of the FLR amount. New technologies leading to liver and tumor 3D reconstruction may guide the surgeon along the best resection planes combining the least liver parenchymal sacrifice with oncological appropriateness. Integration with imaging modalities, such as hepatobiliary scintigraphy, capable of estimating total and regional liver function, may bring about a decrease in postoperative complications. Magnetic resonance imaging with hepatobiliary contrast seems to be predominant since it simultaneously integrates hepatic function and volume information along with a precise characterization of the target malignancy.

Near-infrared cholangiography can increase the chance of success in laparoscopic approaches to common bile duct stones, even with previous abdominal surgery.

BACKGROUND: The treatment of common bile duct (CBD) stones with minimally invasive surgery (MIS) is more technical demanding than laparoscopic cholecystectomy (LC), especially in patients with history of previous abdominal surgery, cholangitis or cholecystitis. Near-infrared (NIR) cholangiography via systemic or biliary tree administration of indocyanine green (ICG), which enhances the visualization of the biliary tree anatomy, may increase the reassurance of CBD localization. The aim of this study was to identify the benefit of near-infrared cholangiography for laparoscopic common bile duct exploration (LCBDE). METHODS: Three groups of CBD stone patients were included in this retrospective study depending on the surgical methods: 1) open choledocholithotomy (OCC), 2) laparoscopic choledocholithotomy (LCC), and 3) near-infrared cholangiography-assisted laparoscopic choledocholithotomy (NIR-CC). For the NIR-CC group, either 3 ml (concentration: 2.5 mg/mL) of ICG were intravenously administered or 10 ml (concentration: 0.125 mg/mL) of ICG were injected directly into the biliary tree. The enhancement rate of the cystic duct (CD), CBD, the upper and lower margin of the CBD were compared using white light image. RESULTS: A total of 187 patients with a mean age of 68.3 years were included (OCC, n = 56; LCC, n = 110; NIR-CC, n = 21). The rate of previous abdominal surgery was significantly lower in the LCC group. The conversion rate was similar between the LCC and the NIR CC groups (p = 0.746). The postoperative hospital stay was significantly longer in the OCC group. No differences in morbidity and mortality were found between the three groups. In the NIR-CC group, the localization of CBD was as high as 85% compared to 24% with white light imaging. CONCLUSIONS: Near-infrared cholangiography helps increase the chance of success in minimally invasive approaches to CBD stones even in patients with previous abdominal surgeries, without increasing the rate of conversion.

Live laparoscopic video retrieval with compressed uncertainty.

Searching through large volumes of medical data to retrieve relevant information is a challenging yet crucial task for clinical care. However the primitive and most common approach to retrieval, involving text in the form of keywords, is severely limited when dealing with complex media formats. Content-based retrieval offers a way to overcome this limitation, by using rich media as the query itself. Surgical video-to-video retrieval in particular is a new and largely unexplored research problem with high clinical value, especially in the real-time case: using real-time video hashing, search can be achieved directly inside of the operating room. Indeed, the process of hashing converts large data entries into compact binary arrays or hashes, enabling large-scale search operations at a very fast rate. However, due to fluctuations over the course of a video, not all bits in a given hash are equally reliable. In this work, we propose a method capable of mitigating this uncertainty while maintaining a light computational footprint. We present superior retrieval results (3%-4% top 10 mean average precision) on a multi-task evaluation protocol for surgery, using cholecystectomy phases, bypass phases, and coming from an entirely new dataset introduced here, surgical events across six different surgery types. Success on this multi-task benchmark shows the generalizability of our approach for surgical video retrieval.

Deep sedation versus orotracheal intubation for endoscopic sleeve gastroplasty (ESG): preliminary experience.

BACKGROUND: Endoscopic sleeve gastroplasty (ESG) is an emerging bariatric procedure currently performed under general anaesthesia with orotracheal intubation (OTI). Several studies have shown the feasibility of advanced endoscopic procedures under deep sedation (DS) without impacting patient outcomes or adverse event rates. Our goal was to perform an initial comparative analysis of ESG in DS with ESG under OTI. METHODS: A prospective institutional registry was reviewed for ESG patients between 12/2016 and 1/2021. Patients were stratified into OTI or DS cohorts, and the 1st 50 cases performed in each cohort were included for comparability. Univariate analysis was performed on demographics, intraoperative, and postoperative outcomes (up to 90 days). Multivariate analyses evaluated the relationship between anesthesia type, preclinical and clinical variables. RESULTS: Of the 50 DS patients, 21(42%) underwent primary and 29 (58%) revisional surgery. There was no significant differences in Mallampati score across groups. No DS patient required intubation. DS patients were younger (p = 0.006) and lower BMI (p = 0.002) than OTI. As expected, DS patients overall and in the primary subgroup had shorter operative time (p ≤ 0.001 and p = 0.003, respectively) and higher rates (84% DS vs. 20% OTI, p ≤ 0.001) of ambulatory procedures. There were no significant differences in the sutures used between groups (p = 0.616). DS patients required less postoperative opioids (p ≤ 0.001) and antiemetics (p = 0.006) than OTI. There were no significant differences in 3-month postoperative weight loss across cohorts. There was no rehospitalization in either group. In primary ESG cases, we found DS patients were more likely younger (p = 0.006), female (p = 0.001), and had a lower BMI (p = 0.0027). CONCLUSIONS: ESG under DS is safe and feasible in select patients. We found DS safely increased rates of outpatient care, reduced use of opioids and antiemetics, and provided the same results of postoperative weight loss. Patient selection for DS may be more clearer for durable weight loss.

Simultaneous, Multi-Channel, Near-Infrared Fluorescence Visualization of Mesenteric Lymph Nodes Using Indocyanine Green and Methylene Blue: A Demonstration in a Porcine Model.

Near-infrared fluorescence (NIRF) image-guided surgery is a useful tool that can help reduce perioperative complications and improve tissue recognition. Indocyanine green (ICG) dye is the most frequently used in clinical studies. ICG NIRF imaging has been used for lymph node identification. However, there are still many challenges in lymph node identification by ICG. There is increasing evidence that methylene blue (MB), another clinically applicable fluorescent dye, can also be useful in the intraoperative fluorescence-guided identification of structures and tissues. We hypothesized that MB NIRF imaging could be used for lymph node identification. The aim of this study was to evaluate the feasibility of intraoperative lymph node fluorescence detection using intravenously (IV) administered MB and compare it to ICG via a camera that has two dedicated near-infrared (NIR) channels. Three pigs were used in this study. ICG (0.2 mg/kg) was administered via a peripheral venous catheter followed by immediate administration of MB (0.25 mg/kg). NIRF images were acquired as video recordings at different time points (every 10 min) over an hour using the QUEST SPECTRUM® 3 system (Quest Medical Imaging, Middenmeer, The Netherlands), which has two dedicated NIR channels for simultaneous intraoperative fluorescence guidance. The 800 nm channel was used to capture ICG fluorescence and the 700 nm channel was used for MB. The target (lymph nodes and small bowel) and the background (vessels-free field of the mesentery) were highlighted as the regions of interest (ROIs), and corresponding fluorescence intensities (FI) from these ROIs were measured. The target-to-background ratio (TBR) was then computed as the mean FI of the target minus the mean FI of the background divided by the mean FI of the background. In all included animals, a clear identification of lymph nodes was achieved at all time points. The mean TBR of ICG in lymph nodes and small bowel was 4.57 ± 1.00 and 4.37 ± 1.70, respectively for the overall experimental time. Regarding MB, the mean TBR in lymph nodes and small bowel was 4.60 ± 0.92 and 3.27 ± 0.62, respectively. The Mann-Whitney U test of the lymph node TBR/small bowel TBR showed that the TBR ratio of MB was statistically significantly higher than ICG. The fluorescence optical imaging technology used allows for double-wavelength assessment. This feasibility study proves that lymph nodes can be discriminated using two different fluorophores (MB and ICG) with different wavelengths. The results suggest that MB has a promising potential to be used to detect lymphatic tissue during image-guided surgery. Further preclinical trials are needed before clinical translation.