Vani J. Konda

Complete Barrett's Eradication Endoscopic Mucosal Resection: An Effective Treatment Modality for High-Grade Dysplasia and Intramucosal Carcinoma—An American Single-Center Experience

OBJECTIVES:Complete Barretts eradication endoscopic mucosal resection (CBE-EMR) is the endoscopic removal of all Barretts epithelium with the curative intent of eliminating high-grade dysplasia (HGD)/intramucosal carcinoma (IMC) and reducing the risk of metachronous lesion development. We report our single tertiary referral centers long-term clinical experience using this modality in HGD/IMC management.METHODS:In this study, we retrospectively reviewed all patients who had CBE-EMR for Barretts esophagus (BE) with HGD/IMC who had been entered into our centers prospectively collected database. High-definition white-light and narrow-band imaging examinations were used according to the protocol. Staging endoscopic ultrasound was done before CBE-EMR to exclude invasive disease or suspicious lymphadenopathy. High-dose proton pump inhibition was instituted after initial treatment, and Seattle-type surveillance biopsies were performed on follow-up every 6 months once the CBE-EMR procedure was completed.RESULTS:A total of 49 patients (mean age 67 years, median 65, s.d. 11; 75% men) with histologically confirmed BE and HGD (33), IMC (16), underwent CBE-EMR from August 2003 to August 2008. The mean BE segment length was 3.2 cm (median 2, s.d. 2.2); 26 patients had short-segment BE, and 30 had visible lesions. A total of 106 EMR procedures were performed. On initial EMR, two patients had superficial submucosal carcinoma invasion (sm1) and two had IMC with lymphatic channel invasion. All four patients were referred for esophagectomy, but one opted for continued endoscopic management, without evidence of residual or recurrent carcinoma. A total of 14 patients await completion of EMR (9) or first follow-up endoscopy (5). CBE-EMR therapy was completed in 32 patients by an average of 2.1 sessions (median 2, s.d. 0.9). Surveillance biopsies showed normal squamous epithelium in 31 of 32 (96.9%) patients (mean remission time 22.9 months, median 17, s.d. 16.7, interquartile range 11–38). In all, 10 of 46 patients who continued in the endoscopic protocol had subsquamous Barretts epithelium on EMR specimens and/or treatment endoscopy biopsies. Overall, 1 of these 10 patients had Barretts underneath squamous mucosa on most recent surveillance biopsies. CBE-EMR upstaged pre-EMR pathology results in 7 of 49 (14%) of patients and downstaged pathology in 15 of 49 (31%) patients. In all, 18 of 49 (37%) patients developed symptomatic esophageal stenosis after a mean of 24.4 days (median 13.5, s.d. 27.8); all were successfully managed by endoscopic treatment. No perforations or uncontrollable bleeding occurred.CONCLUSIONS:To our knowledge, this is the largest American single-center experience demonstrating that CBE-EMR with close endoscopic surveillance is an effective treatment modality for BE with HGD/IMC. Although the rate of stenosis development is significant, it is easily treated by endoscopic dilation. Patients considering endoscopic ablation should be counseled appropriately. The role of CBE-EMR in patients with lymphatic invasion or superficial submucosal invasion remains to be defined.

A pilot study of in vivo identification of pancreatic cystic neoplasms with needle-based confocal laser endomicroscopy under endosonographic guidance

BACKGROUND AND STUDY AIMS Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) of pancreatic cystic lesions (PCL) is flawed by inadequate diagnostic yield. Needle-based confocal laser endomicroscopy (nCLE) utilizes a sub-millimeter probe that is compatible with an EUS needle and enables real-time imaging with microscopic detail of PCL. The aims of the In vivo nCLE Study in the Pancreas with Endosonography of Cystic Tumors (INSPECT) pilot study were to assess both the diagnostic potential of nCLE in differentiating cyst types and the safety of the technique. PATIENTS AND METHODS Eight referral centers performed nCLE in patients with PCL. Stage 1 defined descriptive terms for structures visualized by an off-line, unblinded consensus review. Cases were reviewed with a gastrointestinal pathologist to identify correlations between histology and nCLE. Stage 2 assessed whether the specific criteria defined in Stage 1 could identify pancreatic cystic neoplasms (PCN) including intraductal papillary mucinous neoplasms, mucinous cystic adenoma, or adenocarcinoma in an off-line blinded consensus review. RESULTS A total of 66 patients underwent nCLE imaging and images were available for 65, 8 of which were subsequently excluded due to insufficient information for consensus reference diagnosis. The presence of epithelial villous structures based on nCLE was associated with PCN (P=0.004) and provided a sensitivity of 59%, specificity of 100%, positive predictive value of 100 %, and negative predictive value of 50%. The overall complication rate was 9% and included pancreatitis (1 mild case, 1 moderate case), transient abdominal pain (n=1), and intracystic bleeding not requiring any further measures (n=3). CONCLUSIONS These preliminary data suggested that nCLE has a high specificity in the detection of PCN, but may be limited by a low sensitivity. The safety of nCLE requires further evaluation.

Wireless capsule endoscopy

Over the last decade, WCE has established itself as a valuable test for imaging the small intestine. It is a safe and relatively easy procedure to perform that can provide valuable information in the diagnosis of small-bowel conditions. Its applications still remain limited within the esophagus and colon. Future developments may include improving visualization within the esophagus and developing technologies that may allow manipulation of the capsule within the GI tract and biopsy capabilities.

First assessment of needle-based confocal laser endomicroscopy during EUS-FNA procedures of the pancreas (with videos)

BACKGROUND Challenges in EUS-guided FNA (EUS-FNA) include sampling error, nondiagnostic cytology, and limited on-site cytological evaluation. A prototype needle-based confocal laser endomicroscopy (nCLE) probe is a submillimeter probe that provides real-time imaging at the microscopic level through the FNA needle. OBJECTIVE To evaluate the feasibility of nCLE during EUS-FNA of pancreatic lesions. DESIGN Feasibility study. SETTING Multicenter, tertiary care. PATIENTS Eighteen patients presenting for EUS-FNA. INTERVENTIONS Patients were injected with 2.5 mL of 10% fluorescein. The lesion was interrogated with the nCLE probe positioned at the tip of a 19-gauge FNA needle. MAIN OUTCOME MEASUREMENTS Device integrity, technical ease, safety, and image acquisition. RESULTS Cases included 16 cysts and 2 masses. There were no device malfunctions. Technical challenges were encountered in 6 of 18 attempts to image and reflected challenges with a postloading technique, the longer ferule tip, and a transduodenal approach. Technical feasibility to perform imaging with nCLE during a pancreatic EUS-FNA procedure was achieved in 17 of 18 cases. Ten cases had good to very good image quality. Two serious adverse events occurred; both were pancreatitis requiring hospitalization. LIMITATIONS Limited sample size, small number of patients with confirmed pathological diagnosis, lack of coregistered pathology and images. CONCLUSIONS nCLE in the pancreas is technically feasible via a 19-gauge needle under endosonographic guidance. Future studies will address identification of structures, diagnostic accuracy, and complication profiles. The rate of pancreatitis needs to be further clarified and mitigated.

Titanium Dioxide in the Service of the Biomedical Revolution

Tijana Rajh,*,† Nada M. Dimitrijevic,† Marc Bissonnette,‡ Tamara Koritarov,†,§ and Vani Konda‡ †Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60540, United States ‡Department of Medicine, The University of Chicago Medicine, 5841 South Maryland Avenue, MC 4076, Chicago, Illinois 60637, United States School of Medicine, Boston University, 72 East Concord Street, Boston, Massachusetts 02118, United States

Endoscopic submucosal dissection

ESD is an established effective treatment modality for premalignant and early-stage malignant lesions of the stomach, esophagus, and colorectum. Compared with EMR, ESD is generally associated with higher rates of en bloc, R0, and curative resections and a lower rate of local recurrence. Oncologic outcomes with ESD compare favorably with competing surgical interventions, and ESD also serves as an excellent T-staging tool to identify noncurative resections that will require further treatment. ESD is technically demanding and has a higher rate of adverse events than most endoscopic procedures including EMR. As such,sufficient training is critical to ensure safe conduct and high-quality resections. A standardized training model for Western endoscopists has not been clearly established,but will be self-directed and include courses, animal model training, and optimally an observership at an expert center.Numerous dedicated ESD devices are now available in the United States from different manufacturers. Although the use of ESD in the United States is increasing, issues related to technical difficulty, limited training opportunities and mentors, risk of adverse events, long procedure duration,and suboptimal reimbursement may limit ESD adoption in the United States to a modest number of academic referral centers for the foreseeable future.

Collagen degradation and MMP9 activation by Enterococcus faecalis contribute to intestinal anastomotic leak

Enterococcus faecalis depletes intestinal collagen, activates the host tissue protease MMP9, and contributes to anastomotic leak. Can our gut microbes prevent wound healing? In a new study, Shogan et al. examined whether the bacterium Enterococcus faecalis, normally present in the intestine, contributes to anastomotic leak, the most feared complication after intestinal surgery. They demonstrated that intestinal E. faecalis can produce a tissue-destroying enzyme that affects the normal healing process by breaking down collagen, a protein that is critical to fully seal the intestine after its removal and reconnection. E. faecalis also activates a host gut enzyme, MMP9, further contributing to anastomotic leak. Finally, the authors demonstrated that the most common antibiotic used in intestinal surgery does not eliminate E. faecalis and thus does not prevent anastomotic leak. Even under the most expert care, a properly constructed intestinal anastomosis can fail to heal, resulting in leakage of its contents, peritonitis, and sepsis. The cause of anastomotic leak remains unknown, and its incidence has not changed in decades. We demonstrate that the commensal bacterium Enterococcus faecalis contributes to the pathogenesis of anastomotic leak through its capacity to degrade collagen and to activate tissue matrix metalloproteinase 9 (MMP9) in host intestinal tissues. We demonstrate in rats that leaking anastomotic tissues were colonized by E. faecalis strains that showed an increased collagen-degrading activity and also an increased ability to activate host MMP9, both of which contributed to anastomotic leakage. We demonstrate that the E. faecalis genes gelE and sprE were required for E. faecalis–mediated MMP9 activation. Either elimination of E. faecalis strains through direct topical antibiotics applied to rat intestinal tissues or pharmacological suppression of intestinal MMP9 activation prevented anastomotic leak in rats. In contrast, the standard recommended intravenous antibiotics used in patients undergoing colorectal surgery did not eliminate E. faecalis at anastomotic tissues nor did they prevent leak in our rat model. Finally, we show in humans undergoing colon surgery and treated with the standard recommended intravenous antibiotics that their anastomotic tissues still contained E. faecalis and other bacterial strains with collagen-degrading/MMP9-activating activity. We suggest that intestinal microbes with the capacity to produce collagenases and to activate host metalloproteinase MMP9 may break down collagen in the intestinal tissue contributing to anastomotic leak.

BOB CAT: a Large-Scale Review and Delphi Consensus for Management of Barrett’s Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia

OBJECTIVES:Barrett’s esophagus (BE) is a common premalignant lesion for which surveillance is recommended. This strategy is limited by considerable variations in clinical practice. We conducted an international, multidisciplinary, systematic search and evidence-based review of BE and provided consensus recommendations for clinical use in patients with nondysplastic, indefinite, and low-grade dysplasia (LGD).METHODS:We defined the scope, proposed statements, and searched electronic databases, yielding 20,558 publications that were screened, selected online, and formed the evidence base. We used a Delphi consensus process, with an 80% agreement threshold, using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to categorize the quality of evidence and strength of recommendations.RESULTS:In total, 80% of respondents agreed with 55 of 127 statements in the final voting rounds. Population endoscopic screening is not recommended and screening should target only very high-risk cases of males aged over 60 years with chronic uncontrolled reflux. A new international definition of BE was agreed upon. For any degree of dysplasia, at least two specialist gastrointestinal (GI) pathologists are required. Risk factors for cancer include male gender, length of BE, and central obesity. Endoscopic resection should be used for visible, nodular areas. Surveillance is not recommended for <5 years of life expectancy. Management strategies for indefinite dysplasia (IND) and LGD were identified, including a de-escalation strategy for lower-risk patients and escalation to intervention with follow-up for higher-risk patients.CONCLUSIONS:In this uniquely large consensus process in gastroenterology, we made key clinical recommendations for the escalation/de-escalation of BE in clinical practice. We made strong recommendations for the prioritization of future research.

Tissue adhesives: cyanoacrylate glue and fibrin sealant

The ASGE Technology Committee provides reviews of existing, new, or emerging endoscopic technologies that have an impact on the practice of GI endoscopy. Evidence-based methodology is used, performing a MEDLINE literature search to identify pertinent clinical studies on the topic and a MAUDE (U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported adverse events of a given technology. Both are supplemented by accessing the “related articles” feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Controlled clinical trials are emphasized, but in many cases, data from randomized, controlled trials are lacking. In such cases, large case series, preliminary clinical studies, and expert opinions are used. Technical data are gathered from traditional and Web-based publications, proprietary publications, and informal communications with pertinent vendors. Technology Status Evaluation Reports are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the Committee as a whole, and approved by the Governing Board of the ASGE. When financial guidance is indicated, the most recent coding data and list prices at the time of publication are provided. For this review, the MEDLINE database was searched through August 2012 for relevant articles by using the key words cyanoacrylate, cyanoacrylate glue, cyanoacrylate and gastroenterology, cyanoacrylate and endoscopy, fibrin glue, fibrin sealant, tissue glue and endoscopy. Technology Status Evaluation Reports are scientific reviews provided solely for educational and informational purposes. Technology Status Evaluation Reports are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

Development and Validation of a Classification System to Identify High-Grade Dysplasia and Esophageal Adenocarcinoma in Barrett's Esophagus Using Narrow-Band Imaging

BACKGROUND & AIMS Although several classification systems have been proposed for characterization of Barretts esophagus (BE) surface patterns based on narrow-band imaging (NBI), none have been widely accepted. The Barretts International NBI Group (BING) aimed to develop and validate an NBI classification system for identification of dysplasia and cancer in patients with BE. METHODS The BING working group, composed of NBI experts from the United States, Europe, and Japan, met to develop a validated, consensus-driven NBI classification system for identifying dysplasia and cancer in BE. The group reviewed 60 NBI images of nondysplastic BE, high-grade dysplasia, and esophageal adenocarcinoma to characterize mucosal and vascular patterns visible by NBI; these features were used to develop the BING criteria. We then recruited adult patients undergoing surveillance or endoscopic treatment for BE at 4 institutions in the United States and Europe, obtaining high-quality NBI images and performing histologic analysis of biopsies. Experts individually reviewed 50 NBI images to validate the BING criteria, and then evaluated 120 additional NBI images (not previously viewed) to determine whether the criteria accurately predicted the histology results. RESULTS The BING criteria identified patients with dysplasia with 85% overall accuracy, 80% sensitivity, 88% specificity, 81% positive predictive value, and 88% negative predictive value. When dysplasia was identified with a high level of confidence, these values were 92%, 91%, 93%, 89%, and 95%, respectively. The overall strength of inter-observer agreement was substantial (κ = 0.681). CONCLUSIONS The BING working group developed a simple, internally validated system to identify dysplasia and EAC in patients with BE based on NBI results. When images are assessed with a high degree of confidence, the system can classify BE with >90% accuracy and a high level of inter-observer agreement.