Characterisation and mitigation of gas leaks at laparoscopy: an international prospective, multi-center cohort clinical trial.

INTRODUCTION: Gas leaks polluting the operating room are common in laparoscopy. Studies defining methods for sensitive leak characterisation and mechanical mitigation in real world settings are, however, lacking. METHODS: Mobile optical gas imagers (both a miniaturised Schlieren system and sensitive tripod-mounted near-infrared carbon dioxide camera (GF343, FLIR)) prospectively defined trocar-related gas leaks occurring either spontaneously or with instrumentation during planned laparoscopic surgery at three hospitals. A boutique Matlab-based analyser using sequential frame subtraction categorised leaks (class 0-no observable leak; class 1-marginally detectable leak; class 2-short-lived plume; class 3-energetic, turbulent jet). Concurrently, the usefulness of a novel vacuum-ring device (LeakTrap™, Palliare, Ireland) designed as a universal adjunct for existing standard laparoscopic ports at both abdominal wall and port valve level was determined similarly in a phase I/11 clinical trial along with the device's useability through procedural observation and surgeon questionnaire. RESULTS: With ethical and regulatory approval, 40 typical patients (mean age 58.6 years, 20 males) undergoing planned laparoscopic cholecystectomy (n = 36) and hernia repair (n = 4) were studied comprising both control (n = 20) and intervention (n = 20) cohorts. Dual optical gas imaging was successfully performed across all procedures with minimal impact on procedural flow. In total, 1643 trocar instrumentations were examined, 819 in the control group (mean 41 trocar instrumentations/procedure) and 824 in the intervention group (mean 41.2 trocar instrumentations/procedure). Gas leaks were detected during 948(62.6%) visualised trocar instrumentations (in 129-7.8%-the imaging was obscured). 14.8% (110/742) and 60% (445/742) of leaks in control patients were class 0 and 3, respectively, versus 59.1% (456/770) and 8.7% (67/772) in the interventional group (class 3 v non-class 3, p < 0.0001, χ2). The Leaktrap proved surgically acceptable without significant workflow disruption. CONCLUSION: Laparoscopic gas leaks can be sensitively detected and consistently, effectively mitigated using straightforward available-now technology with most impact on the commonest, highest energy instrument exchange leaks.

Towards automatic verification of the critical view of the myopectineal orifice with artificial intelligence.

BACKGROUND: Visualization of key anatomical landmarks is required during surgical Trans Abdominal Pre Peritoneal repair (TAPP) of inguinal hernia. The Critical View of the MyoPectineal Orifice (CVMPO) was proposed to ensure correct dissection. An artificial intelligence (AI) system that automatically validates the presence of key and marks during the procedure is a critical step towards automatic dissection quality assessment and video-based competency evaluation. The aim of this study was to develop an AI system that automatically recognizes the TAPP key CVMPO landmarks in hernia repair videos. METHODS: Surgical videos of 160 TAPP procedures were used in this single-center study. A deep neural network-based object detector was developed to automatically recognize the pubic symphysis, direct hernia orifice, Cooper's ligament, the iliac vein, triangle of Doom, deep inguinal ring, and iliopsoas muscle. The system was trained using 130 videos, annotated and verified by two board-certified surgeons. Performance was evaluated in 30 videos of new patients excluded from the training data. RESULTS: Performance was validated in 2 ways: first, single-image validation where the AI model detected landmarks in a single laparoscopic image (mean average precision (MAP) of 51.2%). The second validation is video evaluation where the model detected landmarks throughout the myopectineal orifice visual inspection phase (mean accuracy and F-score of 77.1 and 75.4% respectively). Annotation objectivity was assessed between 2 surgeons in video evaluation, showing a high agreement of 88.3%. CONCLUSION: This study establishes the first AI-based automated recognition of critical structures in TAPP surgical videos, and a major step towards automatic CVMPO validation with AI. Strong performance was achieved in the video evaluation. The high inter-rater agreement confirms annotation quality and task objectivity.

International survey among surgeons on the perioperative management of rectal cancer.

BACKGROUND: Several pivotal studies and international guidelines on the perioperative management of rectal cancer have been published. However, little is known about the current state of perioperative management of rectal cancer patients in clinical practice worldwide. METHODS: An online survey including 13 questions focusing on key topics related to the perioperative management of patients with rectal cancer was conducted among colorectal surgeons registered within the database of the Research Institute Against Digestive Cancer (IRCAD). RESULTS: A total of 535 respondents from 89 countries participated in the survey. Most surgeons worked in the European region (40.9%). Two hundred and fifty-four respondents (47.5%) performed less than 25% of surgical procedures laparoscopically. The most commonly used definition of the upper limit of the rectum was a fixed distance from the anal verge (23.4%). Magnetic resonance imaging was used to define the upper limit of the rectum by 258 respondents (48.2%). During total mesorectal excision (TME), 301 respondents (56.3%) used a high-tie technique. The most commonly constructed anastomosis was an end-to-end anastomosis (68.2%) with the majority of surgeons performing a leak test intraoperatively (88.9%). A total of 355 respondents (66.4%) constructed a diverting ostomy, and the majority of these surgeons constructed an enterostomy (82%). A total of 208 respondents (39.3%) closed a stoma within 8 weeks. Lastly, 135 respondents (25.2%) introduced a solid diet on postoperative day 1. CONCLUSION: There is considerable heterogeneity in the perioperative management of rectal cancer patients worldwide with several discrepancies between current international practice and recommendations from international guidelines. To achieve worldwide standardization in rectal cancer care, further research is needed to elucidate the cause of this heterogeneity and find ways of improved implementation of best practice recommendations.

Educational Scoring System in Laparoscopic Cholecystectomy: Is It the Right Time to Standardize?

Background and Objectives: Laparoscopic cholecystectomy (LC) is one of the most performed surgeries worldwide. Procedure difficulty and patient outcomes depend on several factors which are not considered in the current literature, including the learning curve, generating confusing and subjective results. This study aims to create a scoring system to calculate the learning curve of LC based on hepatobiliopancreatic (HPB) experts' opinions during an educational course. Materials and Methods: A questionnaire was submitted to the panel of experts attending the HPB course at Research Institute against Digestive Cancer-IRCAD (Strasbourg, France) from 27-29 October 2022. Experts scored the proposed variables according to their degree of importance in the learning curve using a Likert scale from 1 (not useful) to 5 (very useful). Variables were included in the composite scoring system only if more than 75% of experts ranked its relevance in the learning curve assessment ≥4. A positive or negative value was assigned to each variable based on its effect on the learning curve. Results: Fifteen experts from six different countries attended the IRCAD HPB course and filled out the questionnaire. Ten variables were finally included in the learning curve scoring system (i.e., patient body weight/BMI, patient previous open surgery, emergency setting, increased inflammatory levels, presence of anatomical bile duct variation(s), and appropriate critical view of safety (CVS) identification), which were all assigned positive values. Minor or major intraoperative injuries to the biliary tract, development of postoperative complications related to biliary injuries, and mortality were assigned negative values. Conclusions: This is the first scoring system on the learning curve of LC based on variables selected through the experts' opinions. Although the score needs to be validated through future studies, it could be a useful tool to assess its efficacy within educational programs and surgical courses.

Artificial Intelligence for Surgical Safety: Automatic Assessment of the Critical View of Safety in Laparoscopic Cholecystectomy Using Deep Learning.

OBJECTIVE: To develop a deep learning model to automatically segment hepatocystic anatomy and assess the criteria defining the critical view of safety (CVS) in laparoscopic cholecystectomy (LC). BACKGROUND: Poor implementation and subjective interpretation of CVS contributes to the stable rates of bile duct injuries in LC. As CVS is assessed visually, this task can be automated by using computer vision, an area of artificial intelligence aimed at interpreting images. METHODS: Still images from LC videos were annotated with CVS criteria and hepatocystic anatomy segmentation. A deep neural network comprising a segmentation model to highlight hepatocystic anatomy and a classification model to predict CVS criteria achievement was trained and tested using 5-fold cross validation. Intersection over union, average precision, and balanced accuracy were computed to evaluate the model performance versus the annotated ground truth. RESULTS: A total of 2854 images from 201 LC videos were annotated and 402 images were further segmented. Mean intersection over union for segmentation was 66.6%. The model assessed the achievement of CVS criteria with a mean average precision and balanced accuracy of 71.9% and 71.4%, respectively. CONCLUSIONS: Deep learning algorithms can be trained to reliably segment hepatocystic anatomy and assess CVS criteria in still laparoscopic images. Surgical-technical partnerships should be encouraged to develop and evaluate deep learning models to improve surgical safety.

International survey among surgeons on laparoscopic right hemicolectomy: the gap between guidelines and reality.

INTRODUCTION: To assess the current approaches and perioperative treatments of laparoscopic right hemicolectomy (LRHC) and to highlight similarities and differences with international guidelines and scientific evidence, we conducted a survey for surgeons across the globe. METHODS: All digestive and colorectal surgeons registered with the database of the Research Institute against Digestive Cancer (IRCAD) were invited to take part in the survey via email and through the social media networks of IRCAD. RESULTS: There were a total of 440 respondents from 78 countries. Most surgeons worked in the European region (38.6%) followed by the Americas (34.1%), the Eastern Mediterranean region (13.0%), the South-East Asian region (5.9%), the Western Pacific region (4.8%), and Africa (3.2%) respectively. Over half of the respondents performed less than 25% of right hemicolectomies laparoscopically where 4 ports are usually used by 68% of the surgeons. The medial-to-lateral, vessel-first approach is the approach most commonly used (74.1%). The most common extraction site was through a midline incision (53%) and an abdominal drain tube is routinely used by 52% of the surgeons after surgery. A total of 68.6% of the responding surgeons perform the majority of the anastomoses extracorporeally. Finally, we found that the majority of responders (60.7%) routinely used mechanical bowel preparations prior to LRHC. CONCLUSION: Regarding several topics related to LRHC care, a discrepancy was observed between the current medical practice and the recommendations from RCTs and international guidelines and significant regional differences were observed.

Robotic endoscopic cooperative surgery for colorectal tumors: a feasibility study (with video).

BACKGROUND: Laparoscopic endoscopic cooperative colorectal surgery (LECS-CR) is a promising technique to achieve full-thickness resection of colorectal tumors. This approach has shown good rates of complete resection and low local recurrence, especially for large laterally spreading tumors, which are difficult to remove via endoscopy alone. However, it is often difficult to prevent peritoneal leakage of intestinal content, causing infections and risks of cancer spreading. It was hypothesized that a robotic assistance could make the procedure easier and decrease intestinal fluid leakage. This preclinical trial aims to assess the feasibility of robotic and endoscopic cooperative colorectal surgery (RECS-CR). METHODS: LECS-CR was performed in five female pigs and RECS-CR was also performed in five female pigs. With the animal under general anesthesia, pseudotumors were created on the colonic mucosa at a distance comprised between 20 and 25 cm from the anal verge. Desired resection margins were marked endoscopically and two stay sutures were placed either robotically or laparoscopically. A mucosa-to-submucosa dissection was performed endoscopically along the markings. Complete full-thickness dissection was performed cooperatively. The specimen was withdrawn endoscopically. The colon was closed using a self-fixating running suture. Abdominal contaminations, operating times, complications, and complete resections were evaluated and compared between LECS-CR and RECS-CR. RESULTS: The mean number of colonies of Escherichia coli in the RECS group was significantly lower than in the LECS group (36.7 ± 30.2 vs. 142.2 ± 78.4, respectively, p < 0.05). Operating time was comparable (118 ± 11.2 vs. 98.6 ± 25.7, respectively, p = 0.22). Two stenoses occurred in the LECS group. R0 resection was achieved in all cases. CONCLUSION: This study suggests that RECS-CR is feasible and has the potential to reduce intestinal content leakage, potentially preventing postoperative infections.

Impact of surgical repair on type IV paraesophageal hernias (PEHs).

BACKGROUND: Paraesophageal hernias (PEHs; types II-III-IV) account for about 5% of all hiatal hernias (HHs). The peculiarity of PEHs is the presence of a herniated sac which contains a more or less important part of the stomach, along with other abdominal organs in type IV PEHs. Surgical treatment is more complex since it requires a reduction not only of the herniated content but also of the "container," namely the sac adherent to mediastinal structures. Since type III and IV PEHs are mostly grouped together as large PEHs, there is a lack of articles in the literature with regards to clear surgical outcomes, as well as management algorithms in type IV PEHs. This study aims to compare outcomes in type IV vs. type III PEHs after surgical repair. METHODS: A retrospective study of patients who underwent laparoscopic PEH hernia repair (LPEHR) was conducted in a single institution between 2006 and 2020. Patient baseline characteristics and surgical outcomes were analyzed. RESULTS: A total of 103 patients were included in the analysis. Patients presenting with type IV PEHs (12/103) were significantly older than patients with type III PEHs (91/104) (75.25 ± 7.15 vs. 66.91 ± 13.58 respectively (p = 0.039), and more fragile with a higher Charlson Comorbidity Index (CCI) (4.25 ± 1.48 vs. 2.96 ± 1.72, p = 0.016). Operative time was significantly longer (243 ± 101.73 vs. 133.38 ± 61.76, p = 0.002), and postoperative morbidity was significantly higher in type IV PEH repair (50% vs. 8.8% type III, p = 0.000). CONCLUSION: Patients with type IV PEHs appear to be older and frailer. The higher incidence of postoperative complications in patients with type IV PEHs should advocate for a precise indication for surgical treatment, which should be performed in centers of expertise.

Multicentric validation of EndoDigest: a computer vision platform for video documentation of the critical view of safety in laparoscopic cholecystectomy.

BACKGROUND: A computer vision (CV) platform named EndoDigest was recently developed to facilitate the use of surgical videos. Specifically, EndoDigest automatically provides short video clips to effectively document the critical view of safety (CVS) in laparoscopic cholecystectomy (LC). The aim of the present study is to validate EndoDigest on a multicentric dataset of LC videos. METHODS: LC videos from 4 centers were manually annotated with the time of the cystic duct division and an assessment of CVS criteria. Incomplete recordings, bailout procedures and procedures with an intraoperative cholangiogram were excluded. EndoDigest leveraged predictions of deep learning models for workflow analysis in a rule-based inference system designed to estimate the time of the cystic duct division. Performance was assessed by computing the error in estimating the manually annotated time of the cystic duct division. To provide concise video documentation of CVS, EndoDigest extracted video clips showing the 2 min preceding and the 30 s following the predicted cystic duct division. The relevance of the documentation was evaluated by assessing CVS in automatically extracted 2.5-min-long video clips. RESULTS: 144 of the 174 LC videos from 4 centers were analyzed. EndoDigest located the time of the cystic duct division with a mean error of 124.0 ± 270.6 s despite the use of fluorescent cholangiography in 27 procedures and great variations in surgical workflows across centers. The surgical evaluation found that 108 (75.0%) of the automatically extracted short video clips documented CVS effectively. CONCLUSIONS: EndoDigest was robust enough to reliably locate the time of the cystic duct division and efficiently video document CVS despite the highly variable workflows. Training specifically on data from each center could improve results; however, this multicentric validation shows the potential for clinical translation of this surgical data science tool to efficiently document surgical safety.

Technical Performance of Continuous Pressure Insufflators Versus Traditional Insufflators in the Presence of Leaks During Laparoscopic Surgery.

Background. New insufflators have been developed to manage leaks emanating from the working cavity during laparoscopic surgery. Little data have been published to show the performance of these insufflators. This study evaluates the performance of 2 modern continuous pressure insufflators in various leak conditions. Methods. Performance of a new continuous pressure insufflator, EVA15 (Palliare, Galway, Ireland), was compared with that of a continuous pressure insufflator, Airseal intelligent Flow System (iFS) (CONMED, Utica, NY), and a traditional intermittent pressure insufflator, Endoflator 40 (KARL STORZ, Tuttlingen, Germany). Six different leak scenarios were created in a swine model to create different dynamic leak profiles of between 5 and 15 L/min. Pressure deviation from setting was measured for each insufflator tested. The following were calculated: (a) mean absolute difference of measured insufflation pressure vs. the insufflator pressure setting for the 50 second measurement period (MAD) and (b) standard deviation of the absolute differences (SD). Results. The average mean absolute pressure difference between the EVA15 and Airseal is .27 mmHg. However, the average mean absolute pressure difference between the EVA15 and Endoflator 40 is 2.62 mmHg. Conclusions. Continuous pressure insufflators provide superior pressure delivery performance in leak situations when compared against a traditional intermittent pressure insufflator. No clinically significant performance difference was observed when comparing the EVA15 and Airseal iFS insufflators in the tested leak situations.

A Computer Vision Platform to Automatically Locate Critical Events in Surgical Videos: Documenting Safety in Laparoscopic Cholecystectomy.

OBJECTIVE: The aim of this study was to develop a computer vision platform to automatically locate critical events in surgical videos and provide short video clips documenting the critical view of safety (CVS) in laparoscopic cholecystectomy (LC). BACKGROUND: Intraoperative events are typically documented through operator-dictated reports that do not always translate the operative reality. Surgical videos provide complete information on surgical procedures, but the burden associated with storing and manually analyzing full-length videos has so far limited their effective use. METHODS: A computer vision platform named EndoDigest was developed and used to analyze LC videos. The mean absolute error (MAE) of the platform in automatically locating the manually annotated time of the cystic duct division in full-length videos was assessed. The relevance of the automatically extracted short video clips was evaluated by calculating the percentage of video clips in which the CVS was assessable by surgeons. RESULTS: A total of 155 LC videos were analyzed: 55 of these videos were used to develop EndoDigest, whereas the remaining 100 were used to test it. The time of the cystic duct division was automatically located with a MAE of 62.8 ±â€Š130.4 seconds (1.95% of full-length video duration). CVS was assessable in 91% of the 2.5 minutes long video clips automatically extracted from the considered test procedures. CONCLUSIONS: Deep learning models for workflow analysis can be used to reliably locate critical events in surgical videos and document CVS in LC. Further studies are needed to assess the clinical impact of surgical data science solutions for safer laparoscopic cholecystectomy.

A curriculum to democratize and standardize flexible endoscopy fundamental knowledge and skills: a critical review of the first 5 years of a surgical endoscopy university diploma.

BACKGROUND: As flexible endoscopy offers many advantages to patients, access to training should be aggressively encouraged. In 2014, the IRCAD-IHU-Strasbourg launched a year-long university diploma using advanced education methods to offer surgeons and gastroenterologists high-quality, personalized training in flexible endoscopy. This paper describes and critically reviews the first 5 years of the University Diploma in Surgical Endoscopy (UDSE). METHODS: The UDSE aims to progressively transmit theoretical knowledge, clinical judgment, and practical skills on basic and advanced flexible endoscopy. The 300-h year-long curriculum is composed of 100 h of online lectures with tests, 150 h of clinical rotations and 50 h of hands-on sessions. The hands-on training is delivered through validated mechanical simulators, virtual reality simulators, and specifically designed ex vivo and in vivo animal models. Participants' demographics, training, and clinical experience were recorded. Trainees' evaluations of each online lecture, hands-on training, and clinical rotations were assessed using a Likert scale from 1 (not satisfactory) to 5 (outstanding). Trainees' skill progression was evaluated using the Global Assessment of Gastrointestinal Endoscopic Skills (GAGES) proficiency test. Finally, clinical uptake was surveyed. RESULTS: 162 (79.01% males) trainees from 38 countries enrolled and successfully completed the first 5 courses. The vast majority of the trainees were surgeons and 19.14% were gastroenterologist. Sixty-nine (42.59%) participants were residents and 97 (56.79%) had no prior experience in flexible endoscopy. The online lectures, on-site sessions, and clinical rotations were highly appreciated receiving an overall average score of 4.33/5, 4.56/5, 4.43/5, respectively. Trainees' endoscopic skills improved significantly (16.68 vs. 20.53 GAGES scores; p = 0.016). At an average of 18.83 months following the course, 31 alumni (77.50% of repliers) started to use a flexible endoscope in their practice. CONCLUSIONS: Over its 5-year evolution, the UDSE has proven to be a valid means to ease access to the fundamental knowledge, practical skills, and clinical judgment necessary to achieve proficiency in surgical endoscopy.

Release of hazardous volatile organic compounds from endoscopic submucosal dissection.

BACKGROUND: Although it has been proven that various volatile organic compounds (VOCs) are produced during surgery, there have been no studies focusing specifically on endoscopy. Therefore, we aimed to investigate VOCs produced during endoscopic submucosal dissection (ESD). METHODS: Thirty-one patients scheduled for ESD were enrolled in this study. Sorbent tubes were installed to collect gas at two sites: one in a suction bottle and the other at the level of the endoscopists' upper chest. Gas collections were performed for up to 30 min during submucosal dissection. Quantitative analysis of the VOCs in gas samples was performed using gas chromatography and mass spectrometry. Concentrations of fifteen VOCs were measured. The total concentration of volatile organic compounds (TVOC) was also calculated. RESULTS: Among the five carcinogens-benzene, ethylbenzene, formaldehyde, tetrachloroethylene, and trichloroethylene (TCE)-measured, excess life-time risks of cancer for benzene and TCE were interpreted as unacceptable based on the New Jersey Department of Environmental Protection Division of Air Quality and the Environmental Protection Agency guidelines (5 × 10-4 and 7 × 10-5, respectively). Among the non-carcinogenic VOCs, the mean concentration of toluene was much higher than the reference value (260 µg/m3) in the Japanese guidelines for indoor air quality (IAQ) (1323.7 ± 2884.0 µg/m3 from the air at the upper chest level of endoscopists and 540.9 ± 1345.4 µg/m3 from the suction bottle). Mean TVOCs were at least 10 times higher than the reference value (400 µg/m3) issued by the Japanese guidelines for IAQ. CONCLUSIONS: Various carcinogenic and non-carcinogenic VOCs were detected at levels higher than the reference "safe" values during the submucosal dissection step of ESD. Implementation of counter measures is essential to protect medical personnel who are involved in ESD surgeries.

Three-dimensional imaging improved the laparoscopic performance of inexperienced operators: a prospective trial.

BACKGROUND: Three-dimensional (3-D) high-definition (HD) stereovision and two-dimensional (2-D) ultra-high-resolution (4K) monitors have recently become available for laparoscopic surgery. The aim of this study was to compare laparoscopic performance between inexperienced participants using 3-D/HD and 2-D/4K monitors and those using conventional 2-D/HD monitors. METHODS: The study enrolled 66 participants with no previous surgical experience or medical training. They were randomly divided into three equal groups, each using a different type of monitor (2-D/HD, 2-D/4K, or 3-D/HD), to perform three phantom tasks using a laparoscopic simulator: Task 1, touching markers on a non-flat surface; Task 2, bimanual peg transfer; and Task 3, passing a straight rod through a loop. Each task was performed three times. The performance scores (operative time, path length of the forceps, and technical errors) were compared for each monitor type and by age group (< 30 vs. > 30 years). RESULTS: For all three tasks, scores using the 3-D monitor were significantly better than those using either 2-D monitor, with no difference between the 2-D/4K and 2-D/HD monitors. Using the 2-D monitors, the performance of Task 3 by the participants > 30 years was worse than that by the younger participants; however, there was no difference between the age groups when using the 3-D monitor. CONCLUSION: Participants with no prior experience using a 3-D monitor showed better laparoscopic performance than those using 2-D monitors, even with 4K resolution. This improvement was more marked in older participants, suggesting a greater loss of depth perception in a 2-D environment.

Formalizing video documentation of the Critical View of Safety in laparoscopic cholecystectomy: a step towards artificial intelligence assistance to improve surgical safety.

BACKGROUND: In laparoscopic cholecystectomy (LC), achievement of the Critical View of Safety (CVS) is commonly advocated to prevent bile duct injuries (BDI). However, BDI rates remain stable, probably due to inconsistent application or a poor understanding of CVS as well as unreliable reporting. Objective video reporting could serve for quality auditing and help generate consistent datasets for deep learning models aimed at intraoperative assistance. In this study, we develop and test a method to report CVS using videos. METHOD: LC videos performed at our institution were retrieved and the video segments starting 60 s prior to the division of cystic structures were edited. Two independent reviewers assessed CVS using an adaptation of the doublet view 6-point scale and a novel binary method in which each criterion is considered either achieved or not. Feasibility to assess CVS in the edited video clips and inter-rater agreements were evaluated. RESULTS: CVS was attempted in 78 out of the 100 LC videos retrieved. CVS was assessable in 100% of the 60-s video clips. After mediation, CVS was achieved in 32/78(41.03%). Kappa scores of inter-rater agreements using the doublet view versus the binary assessment were as follows: 0.54 versus 0.75 for CVS achievement, 0.45 versus 0.62 for the dissection of the hepatocystic triangle, 0.36 versus 0.77 for the exposure of the lower part of the cystic plate, and 0.48 versus 0.79 for the 2 structures connected to the gallbladder. CONCLUSIONS: The present study is the first to formalize a reproducible method for objective video reporting of CVS in LC. Minute-long video clips provide information on CVS and binary assessment yields a higher inter-rater agreement than previously used methods. These results offer an easy-to-implement strategy for objective video reporting of CVS, which could be used for quality auditing, scientific communication, and development of deep learning models for intraoperative guidance.

Early-stage clinical evaluation of real-time artificial intelligence assistance for laparoscopic cholecystectomy.

The growing availability of surgical digital data and developments in analytics such as artificial intelligence (AI) are being harnessed to improve surgical care. However, technical and cultural barriers to real-time intraoperative AI assistance exist. This early-stage clinical evaluation shows the technical feasibility of concurrently deploying several AIs in operating rooms for real-time assistance during procedures. In addition, potentially relevant clinical applications of these AI models are explored with a multidisciplinary cohort of key stakeholders.

Stereotactic Pelvic Navigation With Augmented Reality for Transanal Total Mesorectal Excision.

INTRODUCTION: Technical difficulty and unfamiliar surgical anatomy are the main challenges in transanal total mesorectal excision. Precise 3-dimensional real-time image guidance may facilitate the safety, accuracy, and efficiency of transanal total mesorectal excision. TECHNIQUE: A preoperative CT was obtained with 10 skin fiducials and further processed to emphasize the border of the anatomical structure by 3-dimensional modeling and pelvic organ segmentation. A forced sacral tilt by placing a 10-degree wedge under the patient's sacrum was induced to minimize pelvic organ movement caused by lithotomy position. An optical navigation system with cranial software was used. Preoperative CT images were loaded into the navigation system, and patient tracker was mounted onto the iliac bone. Once the patient-to-image paired point registration using skin fiducials was completed, the laparoscopic instrument mounted with instrument tracker was calibrated for instrument tracking. After validating the experimental setup and process of registration by navigating laparoscopic anterior resection, stereotactic navigation for transanal total mesorectal excision was performed in the low rectal neuroendocrine tumor. RESULTS: The fiducial registration error was 1.7 mm. The accuracy of target positioning was sufficient at less than 3 mm (1.8 ± 0.9 mm). Qualitative assessment using a Likert scale was well matched between the 2 observers. Of the 20 scores, 19 were judged as 4 (very good) or 5 (excellent). There was no statistical difference between mean Likert scales of the abdominal or transanal landmarks (4.4 ± 0.5 vs 4.3 ± 1.0, p = 0.965). CONCLUSIONS: Application of an existing navigation system to transanal total mesorectal excision for a low rectal tumor is feasible. The acceptable accuracy of target positioning justifies its clinical use. Further research is needed to prove the clinical need for the procedure and its impact on clinical outcomes.

Modular laser-based endoluminal ablation of the gastrointestinal tract: in vivo dose-effect evaluation and predictive numerical model.

BACKGROUND: Endoscopic submucosal dissection allows for "en bloc" removal of early gastrointestinal neoplasms. However, it is technically demanding and time-consuming. Alternatives could rely on energy-based techniques. We aimed to evaluate a predictive numerical model of thermal damage to preoperatively define optimal laser settings allowing for a controlled ablation down to the submucosa, and the ability of confocal endomicroscopy to provide damage information. MATERIALS AND METHODS: A Nd:YAG laser was applied onto the gastric mucosa of 21 Wistar rats on 10 spots (total 210). Power settings ranging from 0.5 to 2.5W were applied during 1-12 s, with a consequent energy delivery varying from 0.5 to 30 J. Out of the 210 samples, a total of 1050 hematoxilin-eosin stained slides were obtained. To evaluate thermal injury, the ratio between the damage depth (DD) over the mucosa and the submucosa thickness (T) was calculated. Effective and safe ablation was considered for a DD/T ratio ≤ 1 (only mucosal and submucosal damage). Confocal endomicroscopy was performed before and after ablation. A numerical model, using human physical properties, was developed to predict thermal damage. RESULTS: No full-thickness perforations were detected. On histology, the DD/T ratio at 0.5 J was 0.57 ± 0.21, significantly lower when compared to energies ranging from 15 J (a DD/T ratio = 1.2 ± 0.3; p < 0.001) until 30 J (a DD/T ratio = 1.33 ± 0.31; p < 0.001). Safe mucosal and submucosal ablations were achieved applying energy between 4 and 12 J, never impairing the muscularis propria. Confocal endomicroscopy showed a distorted gland architecture. The predicted damage depth demonstrated a significant positive linear correlation with the experimental data (Pearson's r 0.85; 95% CI 0.66-0.94). CONCLUSIONS: Low-power settings achieved effective and safe mucosal and submucosal ablation. The numerical model allowed for an accurate prediction of the ablated layers. Confocal endomicroscopy provided real-time thermal damage visualization. Further studies on larger animal models are required.

Fluorescence lymphangiography-guided full-thickness oncologic gastric resection.

BACKGROUND: We aimed to assess the feasibility of a novel hybrid endoscopic/laparoscopic non-exposed, full-thickness, single-wall gastric resection technique guided by a fluorescence lymphangiography to identify the lymphatic pathway and the sentinel node basin. METHODS: Eight large white pigs (4 acute and 4 survival models) were included. Indocyanine green was injected submucosally around a pseudo-tumor at four points (1 ml, 0.1 mg/ml). The lymphatic spreading pathway was identified by the means of near-infrared (NIR) laparoscopic camera, and the resection line was planned outside of the fluorescent signals, to include all the potential lymphatic channels. Lymph node (LN) dissection was performed at greater curvature side and the infrapyloric area preserving the infragastric artery for all pigs. At the lesser curvature, 3-4 branches of the gastric artery were preserved in all acute and in two survival (group A), while in the remaining animals, 1-2 branches were preserved (group B). Perfusion of the remaining stomach was examined by NIR angiography. The gastric motility and function were evaluated by the means of a dynamic MRI immediately after the procedure and repeated after 1 week in surviving animals. RESULTS: The hybrid full-thickness resection with bilateral sentinel LN basin dissection were successfully performed with no intra-operative or post-operative complications. The removed specimen was including all the area with florescent signal. The remaining stomach demonstrated a good perfusion at the NIR angiography. The dynamic MRI revealed a preserved emptying function in the acute animals and in the group A, and a loss of function in the group B. CONCLUSIONS: Fluorescence-lymphangiography guided hybrid resection was feasible to remove a relatively large part of the stomach including the lymphatic spreading pathway and sentinel basin. The extent of dissection in the lesser curvature side can affect the post-operative function and further researches are warranted to optimize the concept.

Near-infrared cholecystocholangiography with direct intragallbladder indocyanine green injection: preliminary clinical results.

BACKGROUND: Near-infrared (NIR) fluorescence cholangiography by systemic administration of indocyanine green (ICG) enhances the visualization of the biliary tree anatomy. However, the simultaneous enhancement of liver parenchyma can disturb the visualization of critical details. We herein proposed a new technique of NIR cholecystocholangiography by intragallbladder ICG injection to increase the safety during laparoscopic cholecystectomy. METHODS: A total of 46 patients scheduled for laparoscopic cholecystectomy for symptomatic lithiasis (n = 21) or cholecystitis (n = 25) were enrolled. A fluorescence cholangiography by direct gallbladder injection of ICG was performed in all cases. Of them, the ICG was injected through a previously placed percutaneous transhepatic gallbladder drainage catheter (n = 18) or by intraoperative, percutaneous needle puncture of the gallbladder (n = 28). Visualization of biliary structures, including the cystic duct (CD), the common bile and hepatic ducts (CBD and CHD), the gallbladder neck, and the Hartmann's pouch (HP), was performed using White Light (served as control modality) and by NIR enhancement. RESULTS: Cholecystocholangiography provided a significantly higher rate of visualization of the CD in case of cholecystitis with mild adhesions, and an improved visualization of the HP, CBD, and CHD in case of severe inflammation, when compared to White Light observation. There were no benefits of NIR in case of non-inflamed lithiasis. CONCLUSIONS: Clinical translation of NIR cholecystocholangiography has been successful with a noise-free visualization of biliary anatomy. It can be considered in difficult cases to increase the safety of laparoscopic cholecystectomy.