Applications of artificial intelligence in surgery: clinical, technical, and governance considerations.

Artificial intelligence (AI) will power many of the tools in the armamentarium of digital surgeons. AI methods and surgical proof-of-concept flourish, but we have yet to witness clinical translation and value. Here we exemplify the potential of AI in the care pathway of colorectal cancer patients and discuss clinical, technical, and governance considerations of major importance for the safe translation of surgical AI for the benefit of our patients and practices.

Development and Evaluation of a Quality Assessment Tool for Laparoscopic Sleeve Gastrectomy Videos: A Review and Comparison of Academic and Online Video Resources.

BACKGROUND: Video recording of surgical procedures is increasing in popularity. They are presented in various platforms, many of which are not peer-reviewed. Laparoscopic sleeve gastrectomy (LSG) videos are widely available; however, there is limited evidence supporting the use of reporting guidelines when uploading LSG videos to create a valuable educational video. We aimed to determine the variations and establish the quality of published LSG videos, in both peer-reviewed literature and on YouTube, using a newly designed checklist to improve the quality and enhance the transparency of video reporting. METHODS: A quality assessment tool was designed by using existing research and society guidelines, such as the Bariatric Metabolic Surgery Standardization (BMSS). A systematic review using PRISMA guidelines was performed on MEDLINE and EMBASE databases to identify video case reports (academic videos) and a similar search was performed on the commercial YouTube platform (commercial videos) simultaneously. All videos displaying LSG were reviewed and scored using the quality assessment tool. Academic and commercial videos were subsequently compared and an evidence-based checklist was created. RESULTS: A total of 93 LSG recordings including 26 academic and 67 commercial videos were reviewed. Mean score of the checklist was 5/11 and 4/11 for videos published in articles and YouTube, respectively. Academic videos had higher rates of describing instruments used, such as orogastric tube (P < 0.001) and stapler information (P = 0.04). Fifty-four percent of academic videos described short-term patient outcomes, while not reported in commercial videos (P < 0.001). Sleeve resection status was not universally reported. CONCLUSIONS: Videos published in the academic literature are describing steps in greater detail with more emphasis on specific technical elements and patient outcomes and thus have a higher educational value. A new quality assessment tool has been proposed for video reporting guidelines to improve the reliability and value of published video research.

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.

Atrial Flutter After Radiofrequency Ablation for Barrett's Esophagus: A Case Report.

BACKGROUND Barrett's esophagus (BE) is a metaplastic change in the normal esophageal squamous epithelium and is a well-recognized precursor of esophageal adenocarcinoma (EAC). Nowadays, focal radiofrequency ablation is a valid technique for BE treatment by inducing a superficial and focal thermic destruction of metaplastic tissues. According to the literature, the most frequent patient-related adverse events of this procedure are esophageal iatrogenic stenosis, mucosal laceration or perforation of the esophagus, chest pain, and odynophagia/dysphagia. Postoperative heart rhythm abnormalities have been reported very rarely. CASE REPORT A 74-year-old patient with HE was treated by radiofrequency ablation (RFA) with the Barrx™ catheter system. He had 2 symptomatic episodes of atrial flutter in the immediate postoperative period requiring an external electrical cardioversion to induce a return to sinus cardiac rhythm. After atrial flutter ablation, 2 more radiofrequency procedures were performed, without adverse events. A laparoscopic Nissen fundoplication was carried out with complete endoscopic and histologic eradication of BE after 12-month follow-up. To the best of our knowledge, this is the first reported case of atrial flutter after esophageal RFA. Different mechanisms acting on an anatomic predisposing substrate can potentially play a role in starting atrial flutter, and include inflammation, autonomic activation, and myocardial injury. CONCLUSIONS The occurrence of this new type of adverse effect could potentially modify indications and postoperative monitoring of RFA treatment for BE. Endoscopists should know the possibility of this procedural complication in high-risk patients and they should propose alternative techniques or implement close cardiac monitoring in the postoperative period.

Medium-Term Weight Loss and Remission of Comorbidities Following Endoscopic Sleeve Gastroplasty: a Systematic Review and Meta-analysis.

This systematic review and meta-analysis aimed to determine the short- and medium-term weight loss outcomes and comorbidity resolution following endoscopic sleeve gastroplasty. Our search identified 35 relevant studies containing data from 7525 patients. Overall, pooled short-term (12 months) total weight loss (TWL) was 16.2% (95% CI 13.1-19.4%) in 23 studies (n = 5659). Pooled medium-term TWL was 15.4% (95% CI 13.7-17.2%) in 10 studies (n = 4040). Diabetes resolution was 55.4% (95% CI 46-64%), hypertension resolution was 62.8% (95% CI 43-82%), dyslipidaemia resolution was 56.3% (95% CI 49-63%), and obstructive sleep apnoea resolution was 51.7% (95% CI 16.2-87.3%) in four studies (n = 480). This pooled analysis demonstrates that ESG can induce durable weight loss and resolution of obesity-associated comorbidities in patients with moderate obesity.

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.

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.

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.

Patient-specific stomach biomechanics before and after laparoscopic sleeve gastrectomy.

BACKGROUND: Obesity has become a global epidemic. Bariatric surgery is considered the most effective therapeutic weapon in terms of weight loss and improvement of quality of life and comorbidities. Laparoscopic sleeve gastrectomy (LSG) is one of the most performed procedures worldwide, although patients carry a nonnegligible risk of developing post-operative GERD and BE. OBJECTIVES: The aim of this work is the development of computational patient-specific models to analyze the changes induced by bariatric surgery, i.e., the volumetric gastric reduction, the mechanical response of the stomach during an inflation process, and the related elongation strain (ES) distribution at different intragastric pressures. METHODS: Patient-specific pre- and post-surgical models were extracted from Magnetic Resonance Imaging (MRI) scans of patients with morbid obesity submitted to LSG. Twenty-three patients were analyzed, resulting in forty-six 3D-geometries and related computational analyses. RESULTS: A significant difference between the mechanical behavior of pre- and post-surgical stomach subjected to the same internal gastric pressure was observed, that can be correlated to a change in the global stomach stiffness and a minor gastric wall tension, resulting in unusual activations of mechanoreceptors following food intake and satiety variation after LSG. CONCLUSIONS: Computational patient-specific models may contribute to improve the current knowledge about anatomical and physiological changes induced by LSG, aiming at reducing post-operative complications and improving quality of life in the long run.

Democratizing Flexible Endoscopy Training: Noninferiority Randomized Trial Comparing a Box-Trainer vs a Virtual Reality Simulator to Prepare for the Fundamental of Endoscopic Surgery Exam.

BACKGROUND: A considerable number of surgical residents fail the mandated endoscopy exam despite having completed the required clinical cases. Low-cost endoscopy box trainers (BTs) could democratize training; however, their effectiveness has never been compared with higher-cost virtual reality simulators (VRSs). STUDY DESIGN: In this randomized noninferiority trial, endoscopy novices trained either on the VRS used in the Fundamental of Endoscopic Surgery manual skills (FESms) exam or a validated BT-the Basic Endoscopic Skills Training (BEST) box. Trainees were tested at fixed timepoints on the FESms and on standardized ex vivo models. The primary endpoint was FESms improvement at 1 week. Secondary endpoints were FESms improvement at 2 weeks, FESms pass rates, ex vivo tests performance, and trainees' feedback. RESULTS: Seventy-seven trainees completed the study. VRS and BT trainees showed comparable FESms improvements (25.16 ± 14.29 vs 25.58 ± 11.75 FESms points, respectively; p = 0.89), FESms pass rates (76.32% vs 61.54%, respectively; p = 0.16) and total ex vivo tasks completion times (365.76 ± 237.56 vs 322.68 ± 186.04 seconds, respectively; p = 0.55) after 1 week. Performances were comparable also after 2 weeks of training, but FESms pass rates increased significantly only in the first week. Trainees were significantly more satisfied with the BT platform (3.97 ± 1.20 vs 4.81 ± 0.40 points on a 5-point Likert scale for the VRS and the BT, respectively; p < 0.001). CONCLUSIONS: Simulation-based training is an effective means to develop competency in endoscopy, especially at the beginning of the learning curve. Low-cost BTs like the BEST box compare well with high-tech VRSs and could help democratize endoscopy training.

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.

Statistical models to preoperatively predict operative difficulty in laparoscopic cholecystectomy: A systematic review.

BACKGROUND: Laparoscopic cholecystectomy operative difficulty is highly variable and influences outcomes. This systematic review analyzes the performance and clinical value of statistical models to preoperatively predict laparoscopic cholecystectomy operative difficulty. METHODS: PRISMA guidelines were followed. PubMed, Embase, and the Cochrane Library were searched until June 2020. Primary studies developing or validating preoperative models predicting laparoscopic cholecystectomy operative difficulty in cohorts of >100 patients were included. Studies not reporting performance metrics or enough information for clinical implementation were excluded. Data were extracted according to CHARMS, and study quality was assessed using the PROBAST tool. RESULTS: In total, 2,654 articles were identified, and 22 met eligibility criteria. Eighteen were model development, whereas 4 were validation studies. Eighteen studies were at high risk of bias. However, 11 studies showed low concern for applicability. Identified models predict 9 definitions of laparoscopic cholecystectomy operative difficulty, the most common being conversion to open surgery and operating time. The most validated models predict an intraoperative difficulty scale and procedures >90 minutes with an area under the curve of >0.70 and >0.76, respectively. Commonly used predictors include demographic variables such as age and gender (9/18 models) and ultrasound findings such as gallbladder wall thickness (11/18). Clinical implementation was never studied. CONCLUSION: There is a longstanding interest in estimating laparoscopic cholecystectomy operative difficulty. Models to preoperatively predict laparoscopic cholecystectomy operative difficulty have generally good performance and seem applicable. However, an unambiguous definition of operative difficulty, validations, and clinical studies are needed to implement patients' stratification in laparoscopic cholecystectomy.

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.

Surgical data science and artificial intelligence for surgical education.

Surgical data science (SDS) aims to improve the quality of interventional healthcare and its value through the capture, organization, analysis, and modeling of procedural data. As data capture has increased and artificial intelligence (AI) has advanced, SDS can help to unlock augmented and automated coaching, feedback, assessment, and decision support in surgery. We review major concepts in SDS and AI as applied to surgical education and surgical oncology.

COVID-19 Efforts at the Institute of Image Guided Surgery (IHU-Strasbourg): 2020.

We submit a summary of some of the activities of the IHU-Strasbourg during the initial period of the COVID-19 pandemic. These were presented as part of the coronnavation effort coordinated by Dr Adrian Park. Three initiatives are presented as follows: Protect-Est App, healthcare worker stress, and converted diving mask for ventilation. Two of the 3 projects are still ongoing, and one (Predoict-Est) has been adopted nationally.

Indications and Long-Term Outcomes of Conversion of Sleeve Gastrectomy to Roux-en-Y Gastric Bypass.

PURPOSE: Long-term results on sleeve gastrectomy (SG) with more than 10 years report patients needing sleeve revision for weight loss failure, de novo gastroesophageal reflux (GERD), or sleeve complications. The aim of this study was to analyze the results of laparoscopic conversion of failed SG to Roux-en-Y gastric bypass (RYGB). MATERIALS AND METHODS: Retrospective review of a prospectively institutional maintained database to identify patients who underwent conversion of SG to RYGB between 2012 and June 2020. RESULTS: Sixty patients(50 females) underwent conversion to RYGB. Average time to conversion was 5.6 years (2-11). Mean %WL and TWL after SG were respectively 26±8.8% and 33.2±14.1kg. Mean BMI at the time of RYGB was 38.1±7.1 kg/m2. Mean follow-up was 30.4±16.8 months (6-84). Available patients at each time of follow-up: 1 year 59 (98.3%); 2 years 47 (78.3%); 3 years 39 (71.6%); and 5 years 33 (55%). Patients were divided according to indication for revision in weight regain/insufficient weight loss (30 patients) group 1 and GERD/complications (25 patients) group 2. Percentage of excess weight loss at 1, 3, and 5 years follow-up after bypass was for group 1 40.3±17.6, 34.3±19.5, and 23.2±19.4 and for group 2 90.4±37, 62.6±28.2, and 56±35.02. Total weight loss at last follow-up since sleeve was respectively 31kg in group 1 and 46.7kg in group 2 (p=0.002). No mortality was observed. Thirty-day complication rate was 3.3%. CONCLUSION: RYGB after SG is a safe and effective revisional procedure to manage weight regain and de novo GERD, to address complications, and to improve comorbidities.

Endoscopic assessment of morphological and histopathological upper gastrointestinal changes after endoscopic sleeve gastroplasty.

BACKGROUND: 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. OBJECTIVES: This study objectively evaluates endoscopic macroscopic and histopathologic changes within 12-month follow-up (FU) in patients who underwent ESG. SETTING: Retrospective study on a prospective database of patients who underwent ESG at our tertiary referral center between October 2016 and March 2019. METHODS: 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. RESULTS: 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 hernia <4 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). CONCLUSION: ESG is a safe procedure that does not promote the new onset of macroscopic and histopathologic abnormalities within 1-year follow-up.

Percutaneous transhepatic cholangioscopy using a single-operator cholangioscope (pSOC), a retrospective, observational, multicenter study.

BACKGROUND AND AIMS: Percutaneous cholangioscopy (PC) is more complex and invasive than a transpapillary approach, with the need for a large percutaneous tract of 16 French (Fr) on average in order to advance standard percutaneous cholangioscopes. The aim of this study was to investigate whether percutaneous single-operator cholangioscopy (pSOC) using the SpyGlass™ DS system is feasible, safe, and effective in PC for diagnostic and therapeutic indications. MATERIALS AND METHODS: The data of 28 patients who underwent pSOC in 4 tertiary referral centers were retrospectively analyzed. Technical and clinical success for therapeutic procedures was assessed as well as diagnostic accuracy of pSOC-guided biopsies and visualization. Adverse events and the required number and size of dilatations were reviewed. RESULTS: 25/28 (89%) patients had a post-surgical altered anatomy. The average number of percutaneous dilatations prior to pSOC was 1.25 with a mean dilatation size of 11 French. Histopathology showed a 100% accuracy. Visual impression showed an overall accuracy of 96.4%. Technical and clinical success was achieved in 27/28 (96%) of cases. Adverse events occurred in 3/28 (10.7%) cases. CONCLUSION: pSOC is a feasible, safe, and effective technique for diagnostic and therapeutic indications. It may be considered an alternative approach in clinical cases where gastrointestinal anatomy is altered. It has the potential to reduce peri-procedural adverse events and costs. Prospective randomized-controlled trials are necessary to confirm the previously collected data.

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.