Fleischer, David E.

Abstract Background and study aims Dysphagia from esophageal cancer may be palliated with self-expanding metallic stents (SEMS). Controversy exists about the use of dilation before SEMS deployment. Patients and methods We performed a retrospective cohort study of patients who had SEMS placement without fluoroscopy for palliation at Tenwek Hospital in Bomet, Kenya between January 1999 and April 2019. The primary outcome was any serious adverse event (AE) (chest pain, stent migration, perforation, bleeding, or all-cause mortality) within 30 days of the procedure. Various demographic and clinical characteristics, and procedural details, were examined as risk factors. Technical success, defined as correct SEMS placement, and clinical success, defined as dysphagia score improvement without 30-day mortality, were examined. Results A total of 3823 patients underwent SEMS placement, with 2844 (74.4 %) placed in the second decade of the study. Technical and clinical success were achieved in 97.2 % and 95.5 %, respectively, with mean dysphagia scores improving from 3.4 (SD 0.6) to 0.9 (SD 1.3) post-stent placement. AEs occurred in 169 patients (4.4 %). AEs, specifically perforations, were associated with dilation to greater than 36F in the first decade. Perforation rates decreased from the first (4.1 %) to the second decade (0.2 %). Only 30% had complete 30-day follow-up data. Conclusions SEMS placement is a safe, effective method of palliating malignant dysphagia, with low rates of AEs and 30-day mortality and high rates of clinical and technical success. Dilation can facilitate placement of SEMS without fluoroscopy but should not be performed above 36F due to the risk of perforation.

Abstract Background and study aims Limited evidence suggests that endoscopy capacity in sub-Saharan Africa is insufficient to meet the levels of gastrointestinal disease. We aimed to quantify the human and material resources for endoscopy services in eastern African countries, and to identify barriers to expanding endoscopy capacity. Patients and methods In partnership with national professional societies, digestive healthcare professionals in participating countries were invited to complete an online survey between August 2018 and August 2020. Results Of 344 digestive healthcare professionals in Ethiopia, Kenya, Malawi, and Zambia, 87 (25.3 %) completed the survey, reporting data for 91 healthcare facilities and identifying 20 additional facilities. Most respondents (73.6 %) perform endoscopy and 59.8 % perform at least one therapeutic modality. Facilities have a median of two functioning gastroscopes and one functioning colonoscope each. Overall endoscopy capacity, adjusted for non-response and additional facilities, includes 0.12 endoscopists, 0.12 gastroscopes, and 0.09 colonoscopes per 100,000 population in the participating countries. Adjusted maximum upper gastrointestinal and lower gastrointestinal endoscopic capacity were 106 and 45 procedures per 100,000 persons per year, respectively. These values are 1 % to 10 % of those reported from resource-rich countries. Most respondents identified a lack of endoscopic equipment, lack of trained endoscopists and costs as barriers to provision of endoscopy services. Conclusions Endoscopy capacity is severely limited in eastern sub-Saharan Africa, despite a high burden of gastrointestinal disease. Expanding capacity requires investment in additional human and material resources, and technological innovations that improve the cost and sustainability of endoscopic services.

PURPOSE The eastern corridor of Africa is affected by a high burden of esophageal cancer (EC), with > 90% of patients presenting with advanced disease. Self-expanding metal stents (SEMS) have been previously reported as safe and effective for palliation of malignant dysphagia in resource-limited settings; however, access is limited throughout Eastern Africa. METHODS In response to demand for palliative interventions for patients with dysphagia because of EC, the African Esophageal Cancer Consortium (AfrECC) partnered with the Clinton Health Access Initiative to improve access to SEMS in Eastern Africa. We undertook a stepwise implementation approach to (1) identify barriers to SEMS access, (2) conduct a market analysis, (3) select an industry partner, (4) establish regulatory and procurement processes, (5) develop endoscopic training resources, (6) create a medical device registry, and (7) establish principles of accountability. RESULTS Following an evaluation of market demand and potential SEMS manufacturers, Boston Scientific Corporation announced its commitment to launch an access program to provide esophageal SEMS to patients in Tanzania, Kenya, Malawi, and Zambia at a subsidized price. Parallel regulatory and procurement processes were established in each participating country. Endoscopy training courses were designed and conducted, using the Training-of-Trainers model. A device registry was created to centralize data for quality control and to monitor channels of SEMS distribution. Principles of accountability were developed to guide the sustainability of this endeavor. CONCLUSION The AfrECC Stent Access Initiative is an example of a multisector partnership formed to provide an innovative solution to align regional needs with a supply chain for a high-priority medical device.

AbstractVolumetric laser endomicroscopy (VLE) has been shown to improve detection of early neoplasia in Barrett’s esophagus (BE). However, diagnostic performance using histopathology-correlated VLE regions of interest (ROIs) has not been adequately studied. We evaluated the diagnostic accuracy of VLE assessors for identification of early BE neoplasia in histopathology-correlated VLE ROIs. In total, 191 ROIs (120 nondysplastic and 71 neoplastic) from 50 BE patients were evaluated in a random order using a web-based module. All ROIs contained histopathology correlations enabled by VLE laser marking. Assessors were blinded to endoscopic BE images and histology. ROIs were first scored as nondysplastic or neoplastic. Level of confidence was assigned to the predicted diagnosis. Outcome measures were: (i) diagnostic performance of VLE assessors for identification of BE neoplasia in all VLE ROIs, defined as accuracy, sensitivity, and specificity; (ii) diagnostic performance of VLE assessors for only high level of confidence predictions; and (iii) interobserver agreement. Accuracy, sensitivity, and specificity for BE neoplasia identification were 79% (confidence interval [CI], 75–83), 75% (CI, 71–79), and 81% (CI, 76–86), respectively. When neoplasia was identified with a high level of confidence, accuracy, sensitivity, and specificity were 88%, 83%, and 90%, respectively. The overall strength of interobserver agreement was fair (k = 0.29). VLE assessors can identify BE neoplasia with reasonable diagnostic accuracy in histopathology-correlated VLE ROIs, and accuracy is enhanced when BE neoplasia is identified with high level of confidence. Future work should focus on renewed VLE image reviewing criteria and real-time automatic assessment of VLE scans.

Abstract Background Volumetric laser endomicroscopy (VLE) allows for near-microscopic imaging of the superficial esophageal wall and may improve detection of early neoplasia in Barrett’s esophagus (BE). Interpretation of a 6-cm long, circumferential VLE “full scan” may however be challenging for endoscopists. We aimed to evaluate the accuracy of VLE experts in correctly diagnosing VLE full scans of early neoplasia and non-dysplastic BE (NDBE). Methods 29 VLE full scan videos (15 neoplastic and 14 NDBE) were randomly evaluated by 12 VLE experts using a web-based module. Experts were blinded to the endoscopic BE images and histology. The 15 neoplastic cases contained a subtle endoscopically visible lesion, which on endoscopic resection showed high grade dysplasia or cancer. NDBE cases had no visible lesions and an absence of dysplasia in all biopsies. VLE videos were first scored as “neoplastic” or “NDBE.” If neoplastic, assessors located the area most suspicious for neoplasia. Primary outcome was the performance of VLE experts in differentiating between non-dysplastic and neoplastic full scan videos, calculated by accuracy, sensitivity, and specificity. Secondary outcomes included correct location of neoplasia, interobserver agreement, and level of confidence. Results VLE experts correctly labelled 73 % (95 % confidence interval [CI] 67 % – 79 %) of neoplastic VLE videos. In 54 % (range 27 % – 66 %) both neoplastic diagnosis and lesion location were correct. NDBE videos were consistent with endoscopic biopsies in 52 % (95 %CI 46 % – 57 %). Interobserver agreement was fair (kappa 0.28). High level of confidence was associated with a higher rate of correct neoplastic diagnosis (81 %) and lesion location (73 %). Conclusions Identification of subtle neoplastic lesions in VLE full scans by experts was disappointing. Future studies should focus on improving methodologies for reviewing full scans, development of refined VLE criteria for neoplasia, and computer-aided diagnosis of VLE scans.

Objective Surveillance interval protocols after complete remission of intestinal metaplasia (CRIM) post radiofrequency ablation (RFA) in Barrett’s oesophagus (BE) are currently empiric and not based on substantial evidence. We aimed to assess the timeline, location and patterns of recurrence following CRIM to inform these guidelines. Design Data on patients undergoing RFA for BE were obtained from prospectively maintained databases of five (three USA and two UK) tertiary referral centres. RFA was performed until CRIM was confirmed on two consecutive endoscopies. Results 594 patients achieved CRIM as of 1 May 2017. 151 subjects developed recurrent BE over a median (IQR) follow-up of 2.8 (1.4–4.4) years. There was 19% cumulative recurrence risk of any BE within 2 years and an additional 49% risk over the next 8.6 years. There was no evidence of a clinically meaningful change in the recurrence hazard rate of any BE, dysplastic BE or high-grade dysplasia/cancer over the duration of follow-up, with an estimated 2% (95% CI −7% to 12%) change in recurrence rate of any BE in a doubling of follow-up time. 74% of BE recurrences developed at the gastro-oesophageal junction (GOJ) (24.1% were dysplastic) and 26% in the tubular oesophagus. The yield of random biopsies from the tubular oesophagus, in the absence of visible lesions, was 1% (BE) and 0.2% (dysplasia). Conclusions BE recurrence risk following CRIM remained constant over time, suggesting that lengthening of follow-up intervals, at least in the first 5 years after CRIM, may not be advisable. Sampling the GOJ is critical to detecting recurrence. The requirement for random biopsies of the neosquamous epithelium in the absence of visible lesions may need to be re-evaluated.

159 Background: Intensity-modulated proton therapy (IMPT) with small spot size has the potential to reduce dose to normal tissues but also introduces new confounding factors such as setup uncertainty, range uncertainty, and interplay effects due to breathing motion. We investigated plan quality and robustness of IMPT with small spot size for distal esophageal adenocarcinoma (DEA). Methods: 19 patients with DEA treated by IMPT were retrospectively evaluated. Spot sizes ranged from 2 to 6mm, with spot spacing of 5mm. All plans were generated using a commercial treatment planning system. In-house-developed dose-evaluation software modeled time-dependent spot delivery to incorporate interplay effects. Dose-volume-histogram (DVH) indices were used to evaluate plan quality and robustness was evaluated using the DVH band method. Results: For plan quality, median values of clinical target volume D95% and D5%-D95% (normalized to the prescribed doses), total lung mean dose, heart mean dose, and cord Dmax were 1.014, 0.035, 3.82Gy[RBE], 7.73Gy[RBE], 39.16Gy[RBE], respectively. For plan robustness, median band widths of the aforementioned DVH indices were 0.018, 0.048, 0.60Gy[RBE], 4.17Gy[RBE], and 2.36Gy[RBE], respectively. For interplay effects, median values of the aforementioned DVH indices were 0.99, 0.061, 4.07Gy[RBE], 7.87Gy[RBE], and 39.66Gy[RBE], respectively. Seven patients underwent esophagectomy after neoadjuvant chemoradiation, and five, three, and one of them achieved downstaging, near complete response, and pathologic complete response, respectively; R0 resection was achieved in all cases. For all patients, acute side effects were mostly limited to grades 1-2 only. The only grade 3 adverse events were related to feeding tube placement (8 patients); there were no RT-induced pneumonitis or other lung-related toxicities. Conclusions: IMPT plans with small spot size for DEA have good target dose coverage, homogeneity and normal tissue protection. Treatment plans are also robust to uncertainties and interplay effects. Early clinical results demonstrate low acute toxicity and encouraging clinical and pathologic response.

Goals: To investigate factors predictive of progression from nondysplastic Barrett esophagus (NDBE) or low-grade dysplasia (LGD) to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) using a large, prospective cohort of patients, wherein all esophageal biopsies undergo expert gastrointestinal pathologist review. Background: Efficacy and cost-effectiveness of endoscopic surveillance to detect incident EAC in the setting of Barrett esophagus (BE), particularly in NDBE patients, is questioned. Previous studies have reported factors predictive of progression to EAC to guide surveillance intervals, but their strength is limited by small sample size and absence of expert gastrointestinal pathologist involvement in esophageal biopsy review. Study: NDBE and LGD subjects were identified from a prospective registry in a tertiary care center. “Progressors” were BE subjects who developed HGD/EAC>12 months after the initial NDBE or LGD diagnosis. Cox proportional hazards model were used to identify predictors of progression. Results: In total, 318 with NDBE and 301 with BE-LGD (mean age, 62.6 y, 85% male) were included. The mean follow-up was 5.3 years. The 7 NDBE and 21 LGD subjects progressed to HGD/EAC. BE length [hazards ratio (HR), 1.16; 95% confidence interval (CI), 1.03-1.29], presence of nodularity (HR, 4.98; 95% CI, 1.80-11.7), and baseline LGD (HR, 2.57; 95% CI, 1.13-6.57) were significant predictors of progression on multivariate analysis. Conclusions: In this well-defined cohort of NDBE and BE-LGD subjects, BE length, presence of LGD, and nodularity were independent predictors of progression to HGD/EAC. These factors may aid in identifying high-risk patients who may benefit from closer endoscopic surveillance/therapy.