Citations

AbstractBackground and study aims Endoscopic submucosal dissection (ESD) is technically challenging, difficult to learn, and carries a substantial risk of perforation, all of which remain significant barriers to its adoptability. We aimed to determine whether use of a novel scissor-type knife improved efficacy and safety among novice performers of ESD.Materials and methods Following a brief didactic session on ESD, participants performed ESD of two lesions (2 cm diameter) in an ex vivo porcine gastric model. One resection was performed with a conventional knife and the other with the scissor knife (order of knife randomized). We recorded procedure time, successful en bloc resection, and adverse events (including full-thickness perforation and muscle injury) for each dissection. Participants completed a post-study survey.Results 10 endoscopists (8 trainees, 2 staff) considered novices in ESD participated. Compared with the conventional knife, use of the scissor knife was associated with a significantly shorter time to completion of submucosal dissection (mean 6.2 [SD 5.6] vs. 15.6 [SD 15.6] minutes; P = 0.04) and total procedure time was not significantly different (22.1 [SD 13.3] vs. 24.9 [SD 26.5] minutes; P = 0.65). Scissor knife use was also associated with a significantly lower proportion of perforation and/or muscle injury (10.0 % vs. 70.0 %; P < 0.01) and proportion of muscle injury alone (10.0 % vs. 60.0 %; P = 0.02).Conclusions Among novices performing ESD on an ex vivo animal model, use of a scissor knife was associated with a significantly lower proportion of adverse events without prolonging procedure time. Scissor-type knives may improve ESD safety, at least among novices.

Abstract Background and study aims Precise staging in T1 esophageal adenocarcinoma (EAC) is critical in determining candidacy for curative endoscopic resection. High-frequency endoscopic ultrasound (EUS) has demonstrated suboptimal accuracy in T1 EAC staging due to insufficient spatial resolution. Volumetric laser endomicroscopy (VLE) allows for high-resolution wide-field visualization of the esophageal microstructure. We aimed to investigate the role of VLE in staging T1 EAC. Patients and methods Patients undergoing endoscopic mucosal resection (EMR) were prospectively enrolled and only T1 EAC cases were included. EMR specimens were imaged using second-generation VLE immediately after resection. VLE images were analyzed for signal intensity by depth and signal attenuation (dB/mm) in both cross-sectional and en-face orientation. A decision tree model was constructed to combine measured VLE parameters and delineate diagnostic thresholds. Results Thirty EMR scans were obtained – 15 T1a specimens from 9 patients and 15 T1b specimens from 11 patients. T1b specimen VLE scans exhibited higher signal intensity (P < 0.0001) and higher signal attenuation compared to T1a specimens (P = 0.03). A combination of signal attenuation and signal intensity at 150 µm depth yielded optimal diagnostic thresholds and an area under the curve (AUC) of 0.77. VLE signal attenuation was significantly associated with grade of differentiation, irrespective of EAC stage. Conclusions VLE signal intensity and signal attenuation are quantitatively distinct in T1a and T1b EAC and associated with grade of differentiation. This is the first study examining the role of VLE for staging of T1 EAC and demonstrates promising diagnostic performance. With further in vivo validation, VLE may serve a role in staging superficial EAC.

Abstract Background Endoscopic mucosal resection (EMR) can be performed en-bloc in Barrett's esophagus (BE) lesions that are ≤2 cm in size. The true size of a BE lesion may be underestimated under white light endoscopy, limiting the rate of en-bloc resection. Volumetric laser endomicroscopy (VLE) provides high-resolution cross-sectional imaging of BE. A greater number of VLE glands are associated with BE dysplasia and may help predict lesion size. The aim of this study was to determine the association between VLE gland count and outcome of resection. Methods EMR specimens from patients with a history of dysplastic BE were imaged with VLE. EMRs performed on BE lesions ≤2cm in size with intent at en-bloc resection were included. Manual quantification of epithelial glands was performed in blinded fashion. Image visualization enhancement software was used to quantify the surface area occupied by epithelial glands on en-face VLE. Histologic en-bloc (R0) and incomplete (R1) resection of the targeted lesion was defined by the absence and presence of dysplasia and/or cancer at the specimen margins respectively. Results The study sample consisted of 37 EMRs from 31 patients. The mean (SD) size of EMRs was 1.04 (0.37) cm. Pathology showed low-grade dysplasia (N = 12), high-grade dysplasia (N = 19), and intramucosal cancer (N = 6). The en-bloc resection rate was 37.8% (R0: N = 14; R1: N = 23). The mean (SD) number of epithelial glands was 13.0 (6.7) and 28.8 (23.9) for R0 and R1 specimens, respectively, with a statistically significant mean difference of 15.8 glands (95% CI: 2–29, P = 0.02) between the two groups. A gland count of 28 or higher per EMR specimen predicted R1 with 100% sensitivity and 39% specificity (ROC: 0.69). The mean (SD) surface area occupied by epithelial glands in R0 and R1 specimens was 0.98 (1.1) mm2 and 2.3 (2.4) mm2, respectively. There was strong correlation between manual gland counts and epithelial gland surface area (R2: 0.81, P < 0.001). Conclusion A higher number of VLE glands in EMR specimens is associated with a lower en-bloc resection rate suggesting that white-light endoscopy underestimates lesion size and that VLE may have a potential role in lesion margin assessment. Disclosure All authors have declared no conflicts of interest.

AbstractBackground and AimVolumetric laser endomicroscopy (VLE) is used to identify Barrett's esophagus (BE) dysplasia. Selection of a dysplastic region of interest (ROI) can be challenging due to feature variability across a large amount of data. The degree of agreement among VLE users in selecting a ROI has not been studied.MethodsHigh‐definition videos that divided a VLE scan from 18 patients with biopsy‐proven BE dysplasia into 1‐cm segments were reviewed using a four‐quadrant grid superimposed for systematic interpretation. VLE scans were selected based on image quality and appropriate visualization of BE epithelium. Four experienced VLE users rated each quadrant as dysplastic or non‐dysplastic. For quadrants rated as dysplastic, reviewers selected a single timeframe with representative features. A high‐degree of agreement among reviewers was defined as ≥75% agreement on the quadrant diagnosis and ≥50% agreement on selected timeframe (±2 s).ResultsThirty‐one videos, each 32 s in length, comprising 124 quadrants were reviewed. There was high‐agreement among reviewers in 99 (80%) quadrants, of which 68 (69%) were rated as dysplastic. Compared with quadrants rated as non‐dysplastic, ROIs of quadrants rated as dysplastic contained a higher number of epithelial glands (12.7 vs 1.2, P < 0.001) with atypical architecture (54 vs 1, P < 0.001). A statistically significant difference was observed between the signal intensity profiles of quadrants rated as dysplastic and quadrants rated as non‐dysplastic (P = 0.004).ConclusionThis study highlights that experienced VLE users can identify ROIs with high‐degree of agreement. Selected ROIs contained VLE features associated with BE dysplasia.

1 Background: Endoscopic resection (ER) is used to treat early esophageal cancers (EAC). With the advent of techniques such as ESD that can remove large lesions en bloc, it is important to determine if performing piecemeal resections of intramucosal cancers is detrimental. Aim: To evaluate the response rates in patients with esophageal intramucosal adenocarcinoma (IMC) who had a single ER (SR) compared to those treated with piecemeal resection (PR). Methods: This is a cohort study of patients being followed in our BE unit. Patients in a prospectively maintained database with EAC from Jan 1998 to Apr 2012 were assessed. IMC was defined as lesions that were intramucosal without extension into the submucosa. All T1a cancers were verified by two expert gastrointestinal pathologists. We compared the tumor characteristics and recurrence rate between the two groups of SR and PR of IMC. Results: A total of 197 IMC (T1a) lesions in 138 patients were identified. 88(44.7%) lesions were performed SR and 109(55.3%) were PR. Mean follow up time were 45 months (IQR 24-70.5) in SR and 39 months (IQR 26-52, P=0.067) in PR. Complete remission were found of 92.1% (81) in SR and of 93.6% (102) in PR (P=0.788) patients. The recurrence rate was 7.9% in the SR patients, and 6.4% in the PR patients (P=0.699). Median time to progression was 12 months in the SR group (IQR 8-23.5) and 11 months in the PR (IQR 8-22) (P=0.765) group. The mean survival duration was 116.3 months in the SR and 89 months in the PR (P=0.079). No statistical difference in 5-year survival rates was found between SR (83.2%) and PR (80.9%) (P=0.082). Cox proportional hazard model analysis showed local recurrence after EMR was not related to number of specimen resected or technique. Conclusions: PR appears to be as effective a therapy as en bloc for esophageal IMC. Using PR does not appear to affect clinical outcomes.

Objective. Guidelines on antiplatelet medication use during endoscopy are based on limited evidence. We investigate the risk of bleeding and ischemic events in patients undergoing endoscopic mucosal resection (EMR) of esophageal lesions in the setting of scheduled cessation and prompt resumption of clopidogrel. Design. Single centre retrospective review. Patients. Patients undergoing EMR of esophageal lesions. Interventions. Use of clopidogrel before EMR and resumption after EMR. Patients cease antiplatelets and anticoagulants 7 days before EMR and resume clopidogrel 2 days after EMR in average risk patients. Main Outcomes. Gastrointestinal bleeding (GIB) and ischemic events (IE) within 30 days of EMR. Results. 798 patients underwent 1716 EMR. 776 EMR were performed on patients on at least 1 antiplatelet/anticoagulant (APAC). 17 EMR were performed following clopidogrel cessation. There were 14 GIB and 2 IE. GIB risk in the setting of recent clopidogrel alone (0%) was comparable to those not on APAC (1.1%) (P=1.0). IE risk on clopidogrel (6.3%) was higher than those not on APAC (0.1%) (P=0.03). Limitations. Retrospective study. Conclusions. Temporary cessation of clopidogrel before EMR and prompt resumption is not associated with an increased risk of gastrointestinal bleeding but may be associated with increased ischemic events.

AbstractBackground and AimsPositron emission tomography with computed tomography (PET/CT) has been used to detect metastasis in the diagnosis of esophageal adenocarcinoma (EAC). However, the utility of PET/CT to assess primary tumor for endoscopic resectability and prognosis in early EAC remains unclear. We conducted a retrospective study to determine the association of PET/CT findings with histopathological tumor invasion depth and survival outcomes.MethodsEAC patients who underwent PET/CT followed by endoscopic mucosal resection (EMR) were included. Pathology on EMR and survival outcomes from a prospectively maintained database was retrieved. Two radiologists independently reviewed the PET/CT using the following parameters: detection of malignancy, fluorodeoxyglucose (FDG) uptake intensity, FDG focality, FDG eccentricity, esophageal thickness, maximal standard uptake value (SUVmax), and SUVmax ratio (lesion/liver).ResultsThere were 72 eligible patients: 42 (58.3%) had T1a lesions, and 30 (41.7%) had ≥ T1b. Only SUVmax ratio was associated with tumor invasion depth (odds ratio = 2.77, 95% confidence interval 1.26–7.73, P = 0.0075). Using a cut‐off of 1.48, the sensitivity and specificity of SUVmax ratio for identification of T1a lesions were 43.3% and 80.9%, respectively. Adjusting the SUVmax ratio to 2.14, 16.7% (5/30) of ≥ T1b patients were identified without any false‐positive cases. Multivariate analysis showed SUVmax ratio, Charlson comorbidity index, and esophagectomy were independent predictors for survival.ConclusionsSUVmax ratio (lesion/liver) is more accurate in predicting endoscopic resectability and mortality for EAC than other PET/CT parameters and appears promising as a useful adjunct to the current diagnostic work‐up.