Faculty Bibliography

INTRODUCTION: Endoscopic submucosal dissection (ESD) and endoscopic full-thickness resection (EFTR) are therapeutic alternatives to surgery for resection of colon and rectal lesions. In regards to large colon and rectal polyps and tumors, both ESD and EFTR have high en bloc resection rates and low recurrence rates, but are limited by training, procedure length, stability, and instrumentation. The Robotic System (RS) is a new robot-assisted endoscopic platform with multiple degrees of freedom allowing improved visualization, dexterity, and tissue manipulation with traction. This is the first U.S. experience assessing the feasibility and safety of robot-assisted ESD and EFTR in resection of distal colon and rectal lesions and its implication for polyps and tumors.
METHOD(S): This is a multicenter retrospective study from five institutions. Patients with distal colon or rectal lesions who underwent either ESD or EFTR with the RS were included. Each patient's clinical history, endoscopic findings, procedural records, and pathology records were reviewed.
RESULT(S): Forty-one patients underwent either ESD or EFTR with the RS for distal colon or rectal lesions, with an average total resection time of 135.0 minutes (s 62.8, n = 24). On average, lesions were 9.3 cm from the anal verge (range: 2 cm to 17 cm, n = 35) and were 30.0 mm in max diameter (range: 9 to 77 mm, n = 28). There were 13 (31.7%) neoplasms and 23 (56.1%) adenomatous polyps; other lesions included inflammatory polyps, diffuse nodular lymphoid hyperplasia, and granulation tissue-all were suspicious for malignancy. Neoplasms included 11 adenocarcinomas and 2 GISTs. Adenomatous polyps included 11 tubular adenomas and 11 tubulovillous adenomas. Twenty-nine out of 34 patients (85.3%) with either adenomatous polyps or adenocarcinoma were successfully removed with the RS alone. Of these, 23 (79.3%) demonstrated clean margins on pathology. Post-endoscopic complications included rectal pain and bleeding.
CONCLUSION(S): This report demonstrates a role of robotic endoscopy for the safe and effective treatment of natural orifice endoscopic surgical resection, with its benefits including traction and triangulation. As endoscopic surgery in the form of ESD evolves, refinement of the tools and techniques of the robotic platform will allow endoscopists to have shorter learning curves and resection of distal colon and rectal polyps and tumors to have higher negative margin rates, potentially allowing more endoscopists the ability to perform ESD

INTRODUCTION: Colorectal cancer (CRC) can be prevented by removal of polyps during colo-noscopy. Colonoscopy barriers include invasiveness and need of bowel cleansing preparation. Non-invasive CRC stool based tests may increase CRC screening adherence, but are not designed as a tool to identify pre-cancerous polyps. We present data from a novel prep-free colon cancer screening technology for the detection of pre-cancerous polyps.
METHOD(S): An ingestible capsule descends through the gastrointestinal tract via natural motility and scans the colon for structural abnormalities using an ultra-low-dose X-ray source. The data is transmitted to a recorder unit attached to the patient. The test requires no preparation or sedation, allowing patients to continue their daily routine. A 187 patients were performed in the U.S. and Israel designed to assess the safety and effectiveness of the technology in detecting polyps. All sites received EC/IRB approvals. Patients ingested the capsule with a contrast agent and underwent a colonoscopy performed by independent gastroenterologists, who were blinded to the test's results.
RESULT(S): Sensitivity of the capsule in detecting clinically significant polyps (>10 mm) was 76% and specificity was 82% with no severe or serious adverse events reported. Some patients reported mild abdominal pain and nausea. Patient characteristics are shown in Table 1. A survey questionnaire resulted with a score of 4.18 compared to a 2.91 for colonoscopy (P = 0.0011) using a scoring system of 1 (strongly disagree) to 5 (strongly agree) in response to the phrase: "I would recommend the test for colonic screening".
CONCLUSION(S): The reported patient satisfaction, sensitivity, specificity and safety highlights the potential of the capsule technology as a tool for CRC prevention. Further studies are needed to make this technology part of our routine colon cancer prevention armamentarium

BACKGROUND AND AIMS/OBJECTIVE:Artificial intelligence (AI), specifically deep learning, offers the potential to enhance the field of gastrointestinal endoscopy in areas ranging from lesion detection and classification, to quality metrics and documentation. Progress in this field will be measured by whether AI implementation can lead to improved patient outcomes and more-efficient clinical workflow for GI endoscopists. The aims of this article are to report the findings of a multidisciplinary group of experts focusing on issues in artificial intelligence research and applications related to gastroenterology and endoscopy, to review the current status of the field, and to produce recommendations for investigators developing and studying new AI technologies for gastroenterology. METHODS:A multidisciplinary meeting was held on September 28, 2019, bringing together academic, industry, and regulatory experts in diverse fields including gastroenterology, computer and imaging sciences, machine learning, and computer vision, Food and Drug Administration (FDA) and National Institutes of Health (NIH). Recent and ongoing studies in gastroenterology and current technology in AI were presented and discussed, key gaps in knowledge were identified, and recommendations were made for research that would have the highest impact in making advances and implementation in the field of AI to gastroenterology. RESULTS:There was a consensus that AI will transform the field of gastroenterology, particularly endoscopy and image interpretation. Powered by advanced machine learning algorithms, the use of computer vision to endoscopy has the potential to result in better prediction and treatment outcomes for patients with gastroenterology disorders and cancer. Large libraries of endoscopic images, "EndoNet," will be important to facilitate development and application of AI systems. The regulatory environment for implementation of AI systems is evolving, but common outcomes such as colon polyp detection have been highlighted as potential clinical trial endpoints. Other threshold outcomes will be important, as well as clarity on iterative improvement of clinical systems. CONCLUSIONS:Gastroenterology is a prime candidate for early adoption of AI. AI is rapidly moving from an experimental phase to a clinical implementation phase in gastroenterology. It is anticipated that the implementation of AI in gastroenterology over the next decade will have a significant and positive impact on patient care and clinical workflows. Ongoing collaboration among gastroenterologists, industry experts, and regulatory agencies will be important to ensure that progress is rapid and clinically meaningful. However, there are several constraints and areas that will benefit from further exploration, including potential clinical applications, implementation, structure and governance, role of gastroenterologists, and potential impact of AI in gastroenterology.

Artificial intelligence (AI) was first described in 1950; however, several limitations in early models prevented widespread acceptance and application to medicine. In the early 2000s, many of these limitations were overcome by the advent of deep learning. Now AI systems are capable of analyzing complex algorithms and self-learning, we enter a new age in medicine where AI can be applied to clinical practice through risk assessment models, improving diagnostic accuracy and improving workflow efficiency. This article presents a brief historical perspective on the evolution of AI over the last several decades and the introduction and development of AI in medicine in recent years. A brief summary of the major applications of AI in gastroenterology and endoscopy are also presented, which will be reviewed in further detail by several other articles in this issue of GIE.

Introduction: Pancreatic cystic lesions (PCL) are increasingly identified on cross-sectional imaging. Types include intraductal papillary mucinous neoplasms (IPMN), mucinous cystic neoplasms (MCN), serous cystadenoma (SCA), solid pseudopapillary tumors (SPT) and pseudocysts. Given the risk of malignancy associated with MCN and IPMN with high risk features, accurate PCL diagnosis is essential. Endoscopic ultrasound (EUS) with fine needle aspiration (FNA) of cyst fluid for cytology remains important for the classification of PCL, but is limited by the ability to obtain a sufficient sample and cellularity of fluid. The specificity for malignant cytology is 94%, but sensitivity remains low at 51%. Recently, introduction of a novel microforceps biopsy (MFB) device (Moray Micro Forceps, US Endoscopy, Mentor, OH) has enabled EUS-guided through-the-needle biopsies of PCL through a 19-gauge needle. The aim of this study is to compare the technical success and diagnostic yield for PCL using MFB versus cyst fluid studies alone, along with identifying adverse events associated with MFB.
Method(s): We conducted a retrospective chart review of adult patients with PCL diagnosed by cross sectional imaging undergoing EUS-guided FNA with MFB at 2 tertiary academic centers from November 2016 to November 2019. FNA of PCL was performed and cyst fluid was sent for cytology, carcinoembryonic antigen (CEA) levels, and mutational analysis. Cyst biopsy was performed using MFB.
Result(s): 14 patients were included. 71% were female. Median age was 60 years. Location of cysts in pancreas were head (4), body (6), and tail (4). MFB was technically successful in 12 of 14 cases (yield 86%) including 1 case where no cyst fluid was able to be obtained. There were no reported adverse outcomes (bleeding, pancreatitis, perforation, infection, abdominal pain). MFB diagnosed IPMN in 2 patients, neither of which were identified by cytology but were identified by fluid mutational analysis; MCN in 2 patients, 1 of which was identified by cytology; and SCA in 1 patient where cytology was concerning for a mucinous lesion. Both MFB and cytology were concerning for pseudocyst in 1 patient who ultimately was found to have MCN.
Discussion(s): The technical success of MFB is high and is associated with increased overall diagnostic yield without significant adverse events. For distinguishing PCL types, MFB provided additive diagnostic information to fluid cytology in 4 of 14 patients in our study. Including mutational analysis which identified IPMN in 2 patients where cytology was negative, MFB still provided further diagnostic information in 2 additional patients. This study suggests that the addition of MFB to EUS-guided sampling for cytology, CEA and mutational analysis further augments PCL diagnosis. Future studies should elucidate the role of MFB in combination with mutational analysis. [Formula presented]
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Introduction: EUS-guided FNA and FNB have been stagnating at accuracy levels which falls short of patient and physician hopes. False negative results for malignancy continue to range from 4% (expert centers) to 30%. Multiple passes of the needles often slide along the same tract as the first pass, limiting diagnostic yield. FNA requires 5 passes, fewer for the FNB needles. Rapid on-site cytology may lower the number of passes, but it is logistically and financially challenging, without proving to improve accuracy. Repeated passes bend needles out of shape leading to use of a second needle, with high cost implications. Tumor composition can be a mosaic of desmoplasia, necrosis, cystic areas, and malignant cells. If a needle is in the wrong plane then wrong diagnosis occurs. Often fanning hardly moves the needle. We introduce a new needle prototype to improve diagnostic yield and lower false negatives, with use of a device which has five needles.
Method(s): A multi-pass needle has been designed which ensures five specimens will be from various sites, because the five needles are all penetrating at the same time along different planes within the lesion. This needle apparatus uses the same sheath as a standard 19 gauge needle, but within the sheath it houses a five-lumen plastic tube, which separates between the central 22g needle and the four peripheral 25g needles. The ergonomically-designed handle has a two-phase mechanism which allows the endoscopist to first place the 22g needle within the target lesion, which is the same as the process done today, and to then deploy the four 25g needles, which are pre-bent so as to spread out to a diameter of about one cm, when needles are about 3cm from the scope. The additional needles will each, without fanning, obtain specimens near to the central needle, thus a greater representation of tumor will be obtained, completing the procedure in one pass, with better accuracy due to decreasing false negatives. The two channels for suction apply to the single central needle and to the four peripheral needles. Each needle has its own stylet.
Result(s): The accompanying figure shows the InstaFan, a disruptive technological advance, made to improve EUS biopsies. Three in vivo porcine studies found that the 5 needles delivered resulted in five distinct adequate specimens for pathology diagnosis by the cell block method. Porcine EUS found good visibility of the needles, ease of deployment and no side effects from multiple deployments of the onepass device, both in EUS-guided gastric and duodenal biopsies of porcine pancreas and liver.
Conclusion(s): Future directions of the Onepass will be additional in vivo animal safety studies by additional endoscopists followed by first trials in humans. The goal of the Onepass will be to reduce false negatives, thus increasing optimization of tumor diagnosis. [Formula presented] [Formula presented]
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