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Sawas, Tarek

https://orcid.org/0000-0002-0025-9827

A5048497663 | I867280407

Mayo Clinic

The University of Texas Southwestern Medical Center

Citations 23

Risk Factor Profiles Can Distinguish Esophageal Adenocarcinoma From Barrett's Esophagus

American Journal of Gastroenterology | October 15, 2020 | Volume: 116 | Issue: 1 | Pages: 198-201

10.14309/ajg.0000000000001001 | PMID 33065588

INTRODUCTION: It is assumed that screening risk factors for Barrett's esophagus (BE) and prevalent esophageal adenocarcinoma (EAC) are the same. METHODS: A matched case-control study comparing risk factors between EAC and BE was performed. RESULTS: In 1,356 patients (678 with EAC and 678 with BE), heartburn (52.7%), diabetes, hyperlipidemia, hypertension, nonalcoholic steatohepatitis, and metabolic syndrome were less common in EAC (52.7, 29.2, 45.7, 48.2, 12, and 28.5%, resp.) compared with BE (84.5, 37.6, 82.2, 64.6, 18.4, and 44.1%, P < 0.01). Mean alanine aminotransferase and HgA1c levels were also significantly lower in EAC compared with BE. DISCUSSION: Optimal strategies for screening for prevalent EAC may be different than that for BE.
Utilisation of artificial intelligence for the development of an EUS-convolutional neural network model trained to enhance the diagnosis of autoimmune pancreatitis

Gut | October 7, 2020 | Volume: 70 | Issue: 7 | Pages: 1335-1344

10.1136/gutjnl-2020-322821 | PMID 33028668

Objective The diagnosis of autoimmune pancreatitis (AIP) is challenging. Sonographic and cross-sectional imaging findings of AIP closely mimic pancreatic ductal adenocarcinoma (PDAC) and techniques for tissue sampling of AIP are suboptimal. These limitations often result in delayed or failed diagnosis, which negatively impact patient management and outcomes. This study aimed to create an endoscopic ultrasound (EUS)-based convolutional neural network (CNN) model trained to differentiate AIP from PDAC, chronic pancreatitis (CP) and normal pancreas (NP), with sufficient performance to analyse EUS video in real time. Design A database of still image and video data obtained from EUS examinations of cases of AIP, PDAC, CP and NP was used to develop a CNN. Occlusion heatmap analysis was used to identify sonographic features the CNN valued when differentiating AIP from PDAC. Results From 583 patients (146 AIP, 292 PDAC, 72 CP and 73 NP), a total of 1 174 461 unique EUS images were extracted. For video data, the CNN processed 955 EUS frames per second and was: 99% sensitive, 98% specific for distinguishing AIP from NP; 94% sensitive, 71% specific for distinguishing AIP from CP; 90% sensitive, 93% specific for distinguishing AIP from PDAC; and 90% sensitive, 85% specific for distinguishing AIP from all studied conditions (ie, PDAC, CP and NP). Conclusion The developed EUS-CNN model accurately differentiated AIP from PDAC and benign pancreatic conditions, thereby offering the capability of earlier and more accurate diagnosis. Use of this model offers the potential for more timely and appropriate patient care and improved outcome.
Discovery, Validation, and Application of Novel Methylated DNA Markers for Detection of Esophageal Cancer in Plasma

Clinical Cancer Research | September 16, 2019 | Volume: 25 | Issue: 24 | Pages: 7396-7404

10.1158/1078-0432.ccr-19-0740 | PMID 31527170

Abstract Purpose: The burden of esophageal cancer continues to rise, and noninvasive screening tools are needed. Methylated DNA markers (MDM) assayed from plasma show promise in detection of other cancers. For esophageal cancer detection, we aimed to discover and validate MDMs in tissue, and determine their feasibility when assayed from plasma. Experimental Design: Whole-methylome sequencing was performed on DNA extracted from 37 tissues (28 EC; 9 normal esophagus) and 8 buffy coat samples. Top MDMs were validated by methylation specific PCR on tissue from 76 EC (41 adeno, 35 squamous cell) and 17 normal esophagus. Quantitative allele-specific real-time target and signal amplification was used to assay MDMs in plasma from 183 patients (85 EC, 98 controls). Recursive partitioning (rPART) identified MDM combinations predictive of esophageal cancer. Validation was performed in silico by bootstrapping. Results: From discovery, 23 candidate MDMs were selected for independent tissue validation; median area under the receiver operating curve (AUC) for individual MDMs was 0.93. Among 12 MDMs advanced to plasma testing, rPART modeling selected a 5 MDM panel (FER1L4, ZNF671, ST8SIA1, TBX15, ARHGEF4) which achieved an AUC of 0.93 (95% CI, 0.89–0.96) on best-fit and 0.81 (95% CI, 0.75–0.88) on cross-validation. At 91% specificity, the panel detected 74% of esophageal cancer overall, and 43%, 64%, 77%, and 92% of stages I, II, III, and IV, respectively. Discrimination was not affected by age, sex, smoking, or body mass index. Conclusions: Novel MDMs assayed from plasma detect esophageal cancer with moderate accuracy. Further optimization and clinical testing are warranted.
Esophageal overtubes provide no benefit to safety or technical success in upper gastrointestinal tract endoscopic suturing

Endoscopy International Open | July 11, 2019 | Volume: 07 | Issue: 07 | Pages: E919-E921

10.1055/a-0953-2152 | PMID 31304237

Abstract Background and study aim The role of esophageal overtubes in upper gastrointestinal endoscopic suturing is unknown. This study aimed to determine whether overtube use was associated with technical success or adverse events. Patients and methods A retrospective review of consecutive patients who underwent endoscopic suturing for various indications was performed. Results A total of 719 patients underwent endoscopic suturing for various indications, including endoscopic bariatric procedures in 262, stent fixation in 258, defect closure in 190, and hemostasis in nine. An overtube was used in 186 procedures (25.9 %). Technical success was achieved in all cases. Minor mucosal trauma occurred in 15 cases (8.1 %) with use of an overtube, and none without an overtube (P < 0.0001). No full-thickness esophageal perforation or hemorrhage related to overtube use or the suturing device occurred. Conclusions Endoscopic suturing can be performed safely for a variety of indications, including endoscopic bariatric procedures, defect repair, and stent fixation without an esophageal overtube. Minor esophageal mucosal trauma and equipment cost are increased when an overtube is used.
Editorial: giving high‐grade help to low‐grade dysplasia

Alimentary Pharmacology & Therapeutics | May 10, 2019 | Volume: 49 | Issue: 11 | Pages: 1451-1452

10.1111/apt.15257 | PMID 31074898

Linked ContentThis article is linked to Kunzmann et al paper. To view this article, visit https://doi.org/10.1111/apt.15235.
Staging of T1 esophageal adenocarcinoma with volumetric laser endomicroscopy: a feasibility study

Endoscopy International Open | March 22, 2019 | Volume: 07 | Issue: 04 | Pages: E462-E470

10.1055/a-0838-5326 | PMID 30931378

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.
Transcatheter aortic valve replacement in patients with pure native aortic valve regurgitation: A systematic review and meta‐analysis

Clinical Cardiology | October 23, 2018 | Volume: 42 | Issue: 1 | Pages: 159-166

10.1002/clc.23103 | PMID 30350358

This systematic review and meta‐analysis sought to summarize the available evidence on the use of transcatheter aortic valve replacement (TAVR) in patients with Native Aortic Valve Regurgitation (NAVR) and compare outcomes between first and second generation valves. Owing to the improvements in transcatheter heart valve design and procedural success, TAVR has become increasingly performed in broader aortic valve pathologies. We searched Medline, Embase, Cochrane, and Scopus databases from 2007 to 2018 and performed a systematic review on reports with at least 10 patients with aortic valve regurgitation undergoing TAVR procedure. The main outcome of interest was all‐cause mortality at 30 days. A total of 638 patients across 12 studies were included. Mean age ranged from 68 to 84. Society of Thoracic Surgeons score ranged from 5.4% to 13.1% and Logistic EuroSCORE ranged from 18.2% to 33%. The incidence rate of all‐cause mortality at 30 days was found to be 11% (95% CI 7%‐16%; I2 = 20.86%). All‐cause mortality at 30 days for first generation valves had an incidence rate of 15% (95% CI 10%‐20%; I2 = 10%) compared to 7% (95% CI 3%‐13%; I2 = 37%) in second generation valves with subgroup interaction analysis P = 0.059. Device success incidence rate in second generation valves was 92% (95% CI 83%‐99%; I2 = 67%) vs 68% (95% CI 59%‐77%; I2 = 53%) in first generation valves with P = 0.001. TAVR appears to be a feasible treatment choice for NAVR patients at high risk for surgical valve replacement. Second generation valves show promising results in terms of short‐term outcomes.
FA02.06: VOLUMETRIC LASER ENDOMICROSCOPY GLAND QUANTIFICATION CAN GUIDE EN-BLOC RESECTION IN DYSPLASTIC BARRETT’S ESOPHAGUS

Diseases of the Esophagus | September 14, 2018 | Volume: 31 | Issue: Supplement_1 | Pages: 4-5

10.1093/dote/doy089.fa02.06

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.
Clutch cutter is a safe device for performing endoscopic submucosal dissection of superficial esophageal neoplasms: a western experience

Diseases of the Esophagus | June 25, 2018 | Volume: 31 | Issue: 11 | Pages: No page available

10.1093/dote/doy054 | PMID 29939257

Outcomes of oesophageal self‐dilation for patients with refractory benign oesophageal strictures

Alimentary Pharmacology & Therapeutics | May 22, 2018 | Volume: 48 | Issue: 1 | Pages: 87-94

10.1111/apt.14807 | PMID 29785713

SummaryBackgroundCurrent management of refractory benign oesophageal strictures with endoscopic dilations and stenting leads to resolution of dysphagia in only 30% of patients. Oesophageal self‐dilation may be an alternative.AimTo evaluate the efficacy and safety of oesophageal self‐dilation at a tertiary referral centre.MethodsWe conducted a retrospective review of patients with refractory benign oesophageal strictures who participated in oesophageal self‐dilation at Mayo Clinic (Rochester, MN, USA) between 2003 and 2017. Clinical data including stricture characteristics, Dakkak and Bennett Dysphagia Score, number and dates of endoscopies, and complications were collected. A two‐tailed paired Student's t test was used to compare the measures of efficacy, with differences considered significant at a 5% probability level.ResultsWe identified 52 patients with refractory strictures treated with self‐dilation. The median number of endoscopic interventions was reduced from 9.5 (range 5‐30) to 0 (range 0‐3) within 12 months before and after self‐dilation, respectively (P < 0.0001). A median intervention‐free interval of 417 days (IQR 256‐756 days) was observed. The mean dysphagia score at baseline was 2.5 (95% CI 2.2‐2.8) and 0.33 (95% CI 0.11‐0.53) after self‐dilation. 23 of 27 (85%) patients who received enteral nutrition prior to self‐dilation had their feeding tubes removed.ConclusionsOesophageal self‐dilation is an effective way of maintaining oesophageal patency in refractory benign oesophageal strictures, with safety comparable to current standard of care. Prospective studies are needed to further validate the role of self‐dilation in treatment of refractory benign oesophageal strictures.