- Email: [email protected]
Mo1551 Use of Optical Coherence Tomography (OCT) in the Evaluation of Gastric Lesions
Abstracts
Mo1549 Meta-Analysis of the Orbera Intragastric Balloon for the Endoscopic Management of Obesity Badr Al-Bawardy*1, Saurabh S. Mukewar1, Alfred Genco2, Manoel P. Galvao Neto3, Gontrand Lopez-Nava4, Nitin Kumar5, Christopher C. Thompson5, Erik B. Wilson6, Sohail Shaikh5, Natan Zundel7, Christopher J. Gostout1, Barham K. Abu Dayyeh1 1 Mayo Clinic, Rochester, MN; 2Sapienza University of Rome, Rome, Italy; 3 Gastro Obesity Center, São Paulo, Brazil; 4Bariatric Endoscopy Unit, Madrid Sanchinarro University Hospital, Madrid, Spain; 5Brigham and Women’s Hosptial, Boston, MA; 6Univesrity of Texas, Houston, TX; 7FIU Herbert Wertheim College of Medicine, Miami, FL Background and Aims: The Orbera Intragastric Balloon (IGB) System has been widely used outside the United States (US) as an effective adjunct to life-style modification in the management of mild to moderate obesity. We performed a systematic review and meta-analysis to summarize the out of the US safety and efficacy experience with this IGB system in anticipation of its possible use in the US after regulatory approval. Methods: A comprehensive search of Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science was conducted. The search strategy was designed and conducted by an experienced librarian with input from the study’s team. Two independent reviewers reviewed all citation and identify full-length clinical studies, published in English, investigating use of the Orbera IGB system for obesity. A random-effect meta-analysis and meta-regression were performed. Results: Eighty studies including 8506 patients were included in this meta-analysis. The pooled percent total body weight (%TBW) lost after a single six-months IGB insertion was 12.7% [95% CI 8.5-16.9], 13% [95% CI 11.7-14.7], 10 [95% CI 6.6-13.6], and 6.2 [95% CI 1.4-10.9] at 3, 6, 12, and 36 months respectively. The pooled incidences of side-effects were as following: pain 33.7%, nausea 29%, GERD 18.5%, early removal 7.5%, gastric ulcers 2%, migration 1.4%, small bowel obstruction 0.3%, perforation 0.1%, and death 0.08%. Five included studies were randomized controlled trials (RCTs) that compared the Orbera IGB system to sham or life-style interventions. The mean extra weight lost after Orbera over that in the control arm at 6 months was -8.5kg [95% CI -13 - -4.23] (p!0.001). Three different RCTs evaluated the efficacy sequential use of the Orbera IGB system compared to single use. The mean decrease in body mass index (BMI) after two sequential treatments with Orbera IGB was -4 [95% CI -7.7 - -0.04] (pZ 0.047) over that seen with single treatment at 12 months after insertion. A meta-regression showed that higher IGB fill volumes are associated with greater weight loss at six months (p % 0.001) (figure). A funnel plot did not reveal any evidence of publication bias. Conclusions: The Orbera IGB system seems to produce predictable and significant weight loss with a favorable safety profile that should make it a valuable tool for the management of obesity once approved for use in the United States.
Mo1550 Multicenter Prospective Study About Histological Diagnosis of Gastric Cancer by White Light and NBI Magnified Endoscopy With and Without Acetic Acid Takaaki Kishino*1, Tsuneo Oyama2, Eiji Ishii3, Manabu Takeuchi4, Tokuma Tanuma5, Kotaro Shibagaki6, Tadashi Miike7, Keita Funakawa8, Yoko Kitamura9, Tetsuro Yamazato10, Yasuharu Kuwayama11 1 Gastroenterology, Saku Central Hospital Advanced Care Center, Saku, Japan; 2Endoscopy, Saku Central Hospital Advanced Care Center, Saku, Japan; 3Gastroenterology, Kameda Medical Center, Kamogawa, Japan; 4 Gastroenterology, Niigata University Medical and Dental Hospital, Niigata, Japan; 5Gastroenterology, Teine Keijinkai Hospital, Sapporo, Japan; 6Gastroenterology, Tottori Municipal Hospital, Tottori, Japan; 7 Gastroenterology, University of Miyazaki, Miyazaki, Japan; 8Digestive Disease and Life-style Related Disease, Kagoshima University School of Medical and Dental Sciences, Kagoshima, Japan; 9Gastroenterology, Nara city hospital, Nara, Japan; 10Gastroenterology, Tokyo Metropolitan Cancer Detection Center, Hutyu, Japan; 11Gastroenterology, Tokushima Red Cross Hospital, Komatsushima, Japan Background: The usefulness of NBI magnified endoscopy (NBI-ME) in diagnosing histological type (HT) of gastric cancer (GC) is unclear. Objective: The aim of this study is to evaluate the diagnostic accuracy for HT of GC by white light endoscopy (WL), NBI-ME and NBI-ME with acetic acid (NBI-AA). Design: Multicenter prospective study (UMIN 000006042) Materials: Depressed-type GCs resected by ESD from Aug. 2011 to Jul. 2014 in 10 institutes were prospectively enrolled in the study. 221 cases were analyzed whose point by point cross-evaluation of ME and histology was possible. Methods: Endoscopic diagnosis: A 3mm area in oral edge of the lesion was selected as a target area (TA) to diagnose HT. Two marks were placed between the TA to compare endoscopic and histological findings. At first, the HT of TA was diagnosed by WL, followed by NBI-ME and NBI-AA. The HT was classified into well (wel), moderately (mod) and poorly (poor) differentiated type. In WL, homogeneous red or whitish lesions, strong or spotted red lesions and undemarcated whitish lesions were diagnosed as wel, mod and poor, respectively. NBI-ME findings were classified based on vascular and surface patterns. Vascular pattern was diagnosed based on vascular networks (NW) and irregularity. If NW was present, HT was diagnosed as wel. If NW was absent, it was diagnosed based on vascular irregularity. Surface patterns were grouped into pit, villous and unclear pattern. When pit pattern was identified, HT was diagnosed as wel or mod based on irregularity. Villous pattern was subgrouped into villi, micro-villi and fusioned villi. Villi and micro-villi was diagnosed as wel and mod, respectively. In case of fusioned villi and unclear pattern, HT was diagnosed based on vascular irregularity. In NBI-AA, HT was diagnosed based on surface patterns alone. When the surface pattern was unclear, it was diagnosed as poor. Pathological diagnosis: An expert pathologist diagnosed the HT of TA. Result: Histological types of target areas were wel, mod and poor in 166, 40 and 15 cases, respectively. The sensitivity of wel, mod and poor by WL, NBI-ME and NBI-AA were 99.4% (165/166), 89.6% (149/166) and 94.6% (157/166) in wel, 0% (0/ 40), 20% (8/40) and 12.5% (5/40) in mod and 60% (9/15), 60% (9/15) and 60% (9/15) in poor, respectively. There were no significant differences. Sub-analysis: The diagnostic accuracy by surface pattern in NBI-ME was 100% (20/20) in pit pattern, 78.9% (120/152) in villous pattern and 53.1% (26/49) in unclear pattern. And NBI-AA changed these diagnostic accuracy 100% (20/20), 78.3% (119/152) and 65.3% (32/49) respectively. While the diagnostic accuracy by unclear pattern in NBI-ME was low compared to other surface patterns, NBI-AA improved it from 53.1% to 65.3%. Conclusion: NBI-AA is useful for histological diagnosis of gastric cancers when surface pattern is unclear in NBI-ME.
Mo1551 Use of Optical Coherence Tomography (OCT) in the Evaluation of Gastric Lesions Ming-Ming Xu*, Stephen M. Lagana, Amrita Sethi Gastroenterology, Columbia University, New York City, NY Background & Aims: Optical coherence tomography (OCT) is a light-based imaging modality that allows high resolution, microscopic level cross-sectional imaging of the mucosa of the gastrointestinal tract during endoscopy (Huang 1991). It has been described in the evaluation of Barrett’s esophagus and colonic polyps for identifying areas of dysplasia in-vivo during endoscopy (Das 2001, Pfau 2003). To date however, there have been no studies describing the imaging characteristics of OCT in the stomach. The aim of this study was to describe OCT findings when imaging a range of gastric mucosal lesions and correlate these images with histopathology. Method: Between July 2014 to October 2014 patients referred for endoscopic submucosal dissection (ESD) for a suspicious appearing gastric lesion or prior biopsy showing LGD underwent volumetric laser endomicroscopy (Nvision VLE imaging system, Nine Point Medical) imaging of the stomach during their endoscopy. The Nvision VLE system is a commercially available OCT device with an axial resolution of 7mm and image depth of 3mm. VLE images of the gastric lesion(s) were retrospectively paired with the histopathology of each resected specimens to correlate VLE findings with the associated histology ranging from gastric mucosa with intestinal metaplasia
AB462 GASTROINTESTINAL ENDOSCOPY Volume 81, No. 5S : 2015
www.giejournal.org
Abstracts
(IM), low grade dysplasia (LGD), high grade dysplasia (HGD), to submucosal tumor. Results: Five patients underwent OCT imaging with the VLE system using a 20mm balloon. All exams were technically successful. A total of 80 VLE-biopsy paired images were retrospectively reviewed by the investigators and a GI pathologist. Patient demographics, endoscopic and endosonographic findings, VLE findings, and histopathology are detailed in Table 1. The following types of lesions were visualized: normal gastric mucosal with focal IM, LGD, HGD and neuroendocrine tumor. VLE images of normal gastric epithelium demonstrates alternating areas of high and lower reflectivity (or scattering) resulting in a stippled appearance of the mucosal surface with “pit and crypt” architecture. Both LGD and HGD results in a loss of pit and crypt architecture, higher surface reflectivity (due to increased nuclear to cytoplasmic ratio in dysplastic tissue) and heterogeneous appearence of the mucosal layer. In the presence of submucosal tumor, the dense tumor infiltration is seen on VLE as high depth penetration with more defined layering differentiating the mucosal and submucosal layers. Conclusion: OCT images of the stomach are distinctive and notably different from the well-defined architecture of the esophagus. This small series demonstrates circumferential OCT imaging is feasible in the stomach and may have a role in the evaluation of suspicious gastric lesions. Further study is needed to determine findings that may be more specific to differentiating degrees of dysplasia and carcinoma. Table 1. Characteristics of gastric lesions evaluated by VLE Case No
VLE balloon size
Age
Sex
Abdominal symptoms
Endoscopic findings
1
69
F
Diarrhea
Nodularity, erythema in antrum
No visible lesion noted
20mm
2
69
F
Pain
Gastric antral ulcer
Not performed
20mm
3
67
F
Pain, bloating
Mass with oozing, ulceration on greater curvature
Intramucosal hypoechoic 10mm lesion
20mm
4
68
F
Pain
Two ulcerated nodules gastric cardia
Submucosal hypoechoic 1.7cm x 0.7cm lesion, 0.5x0.8cm satellite lesion
20mm
5
81
F
Early satiety, weight loss
Thickened folds in antrum
Not performed
20mm
EUS findings
VLE findings
Pathology
Loss of pit and crypt architecture, subtle layering, low scattering mucosal structures Loss of pit and crypt architecture, high surface reflectivity with heterogeneous texture Loss of pit and crypt architecture, high surface reflectivity, clustering of dilated mucosal and submucosal structures Loss of pit and crypt architecture, heterogeneous scattering, dense demarcation between mucosa and low-scattering submucosal structure Loss of pit and crypt architecture. Homogenous scattering.
Gastric mucosa, focal IM
LGD
Part A: adenoma with LGD Part B: adenoma with focal HGD
Well differentiated neuroendocrine tumor, low grade (carcinoid), T2 invades muscularis propria
Gastric mucosa with IM
tivity. (C) Gastric adenoma with LGD and HGD presents as a loss of pit and crypt architecture with a proliferation of clustered, dilated atypical glands. (D) Finally, a neuroendocrine tumor of the stomach presents as a loss of pit and crypt architecture with a distinct, low scattering submucosal structure, clearly delineated from surrounding tissue.
Mo1552 A Proof-of-Principle Assessment of the Role of Light-NBI Endoscopy to Assess High-Risk Phenotype for Gastric Cancer: Endoscopy Replaces Histology? Jorge Lage*3, Pedro Pimentel-Nunes3, Pedro C. Figueiredo1, Diogo Libânio3, Iolanda Ribeiro2, Manuel Jácome4, Luís Afonso4, Mario Dinis-Ribeiro3 1 Gastroenterology, Hospital Garcia da Orta, Almada, Portugal; 2 Gastroenterology, Centro Hospitalar de Vila Nova de Gaia, Vila Nova de Gaia, Portugal; 3Gastroenterology, Portuguese Oncology Institute of Porto, Porto, Portugal; 4Pathology, Portuguese Oncology Institute of Porto, Porto, Portugal Introduction: Patients with extensive intestinal metaplasia and/or those OLGIM stages III-IV merit surveillance leading to early diagnosis of gastric cancer and improvement of patients survival (Dinis-Ribeiro M 2012). High-resolution NBI has been shown to accurately determine the presence of IM at specific sites (PimentelNunes P 2012). We hypothesized that the new Olympus system could be used to estimate extensive intestinal metaplasia (eIM) and it could replace or at least be used to target biopsies. Therefore we aimed at assessing the reliability and accuracy of the new Olympus system to assess the presence of eIM on a per-patient basis. Methods: A consecutive series of 25 patients (mean age 59.6 years old, 40% male) without known precancerous conditions or lesions in the stomach were submitted to upper gastrointestinal endoscopy using the 190 series of Olympus. Still images recorded using non-magnified pictures with wight-light endoscopy (WLE) of the antrum, angle, corpus lesser curvature in retroversion and greater curvature in anteversion (4 images); at the same positions with light NBI (L-NBI) (4 different images); and 5 magnified images (MAG) using close focus at antrum (lesser and greater curvature), angle and corpus (lesser and greater curvature). With two different levels of expertise, 6 endoscopists were asked to independently and blinded to histology record their suggested diagnosis of the extensive IM according to each technique (WLE only and/or L-NBI; without or with magnified observations). All images were randomly shown between observations. Biopsies from the antrum, incisura and corpus were sent in different vials according to guidelines (MAPS) and OLGIM used as gold standard. Results: The prevalence of OLGIM III/IV stages and eIM in this sample was 28% and 40% of patients, respectively (whereas 40% had no IM in endoscopic biopsies). With 21% of images considered to be low quality, 4/6 endoscopists increased their certainty by using WLE+L-NBI+MAG view vs WLE to describe findings and 3/6 increased the global accuracy to estimate OLGIM status and eIM. The accuracy to identify those with eIM is optimized in all observers comparing WLE with the use of L-NBI and magnified view vs WLE (LR+ from 3,33 to 6,72; LR- from 0,58 to 0,29 for OLGIM III/IV). Also, the inter-observer reliability increased both in trainees and in experts. Conclusions: In this report, for the first time the reliability of endoscopic features for extension of IM is described. Moreover, we conclude that with proper training endoscopic assessment of gastric mucosa can adequately select 3/4 of patients that would merit surveillance (according to OLGIM grade) if biopsies have been performed and that endoscopy alone can detect up to 90% of those with eIM. Further validation larger cohorts are crutial to understand the precise accuracy.
Summary of results
Figure 1. VLE findings in normal and diseased gastric tissue. (A) Normal gastric tissue has a regular foveolar appearance on VLE, with characteristic ‘pits and crypts’ presenting as superficial striations in the image. (B) In focal IM with LGD, the corresponding VLE image shows a disruption to the normal ‘pit and crypt’ architecture, along with increased surface reflec-
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Certainty Global proportion of agreement with histology Trainees Experts Global accuracy OLGIM Trainees Experts Sensitivity OLGIM III/IV False+ rateOLGIM III/IV Interobserver reliability (wK (95%CI)) Trainees Experts
WLE (% (range))
L-NBI (% (range))
WLE+L-NBI (% (range))
WLE+L-NBI+MAG (% (range))
45 (20-56) 60 (48-64)
49 (20-76) 63 (48-76)
50 (36-60) 65 (56-72)
64 (48-88) 73 (56-92)
59 (48-64) 61 (60-64) 58 (44-72)
56 (48-60) 69 (56-76) 59 (48-76)
61 (56-68) 68 (60-72) 61 (52-76)
63 (46-68) 83 (76-92) 64 (52-76)
53 (44-60) 63 (56-72) 50 (29-86) 15 (4-44) 0,42 (0,26-0,62)
53 (48-60) 64 (52-76) 62 (14-100) 10 (0-28) 0,55 (0,39-0,73)
57 (52-60) 65 (56-76) 62 (29-86) 13 (4-28) 0,50 (0,32-0,68)
55 (52-56) 75 (72-76) 74 (43-86) 11 (0-25) 0,60 (0,43-0,76)
0,33 (0,09-0,59) 0,61 (0,39-0,79)
0,41 (0,16-0,65) 0,61 (0,39-0,79)
0,40 (0,15-0,64) 0,70 (0,50-0,84)
0,44 (0,19-0,67) 0,78 (0,62-0,89)
Volume 81, No. 5S : 2015 GASTROINTESTINAL ENDOSCOPY AB463
Mo1549 Meta-Analysis of the Orbera Intragastric Balloon for the Endoscopic Management of Obesity Badr Al-Bawardy*1, Saurabh S. Mukewar1, Alfred Genco2, Manoel P. Galvao Neto3, Gontrand Lopez-Nava4, Nitin Kumar5, Christopher C. Thompson5, Erik B. Wilson6, Sohail Shaikh5, Natan Zundel7, Christopher J. Gostout1, Barham K. Abu Dayyeh1 1 Mayo Clinic, Rochester, MN; 2Sapienza University of Rome, Rome, Italy; 3 Gastro Obesity Center, São Paulo, Brazil; 4Bariatric Endoscopy Unit, Madrid Sanchinarro University Hospital, Madrid, Spain; 5Brigham and Women’s Hosptial, Boston, MA; 6Univesrity of Texas, Houston, TX; 7FIU Herbert Wertheim College of Medicine, Miami, FL Background and Aims: The Orbera Intragastric Balloon (IGB) System has been widely used outside the United States (US) as an effective adjunct to life-style modification in the management of mild to moderate obesity. We performed a systematic review and meta-analysis to summarize the out of the US safety and efficacy experience with this IGB system in anticipation of its possible use in the US after regulatory approval. Methods: A comprehensive search of Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science was conducted. The search strategy was designed and conducted by an experienced librarian with input from the study’s team. Two independent reviewers reviewed all citation and identify full-length clinical studies, published in English, investigating use of the Orbera IGB system for obesity. A random-effect meta-analysis and meta-regression were performed. Results: Eighty studies including 8506 patients were included in this meta-analysis. The pooled percent total body weight (%TBW) lost after a single six-months IGB insertion was 12.7% [95% CI 8.5-16.9], 13% [95% CI 11.7-14.7], 10 [95% CI 6.6-13.6], and 6.2 [95% CI 1.4-10.9] at 3, 6, 12, and 36 months respectively. The pooled incidences of side-effects were as following: pain 33.7%, nausea 29%, GERD 18.5%, early removal 7.5%, gastric ulcers 2%, migration 1.4%, small bowel obstruction 0.3%, perforation 0.1%, and death 0.08%. Five included studies were randomized controlled trials (RCTs) that compared the Orbera IGB system to sham or life-style interventions. The mean extra weight lost after Orbera over that in the control arm at 6 months was -8.5kg [95% CI -13 - -4.23] (p!0.001). Three different RCTs evaluated the efficacy sequential use of the Orbera IGB system compared to single use. The mean decrease in body mass index (BMI) after two sequential treatments with Orbera IGB was -4 [95% CI -7.7 - -0.04] (pZ 0.047) over that seen with single treatment at 12 months after insertion. A meta-regression showed that higher IGB fill volumes are associated with greater weight loss at six months (p % 0.001) (figure). A funnel plot did not reveal any evidence of publication bias. Conclusions: The Orbera IGB system seems to produce predictable and significant weight loss with a favorable safety profile that should make it a valuable tool for the management of obesity once approved for use in the United States.
Mo1550 Multicenter Prospective Study About Histological Diagnosis of Gastric Cancer by White Light and NBI Magnified Endoscopy With and Without Acetic Acid Takaaki Kishino*1, Tsuneo Oyama2, Eiji Ishii3, Manabu Takeuchi4, Tokuma Tanuma5, Kotaro Shibagaki6, Tadashi Miike7, Keita Funakawa8, Yoko Kitamura9, Tetsuro Yamazato10, Yasuharu Kuwayama11 1 Gastroenterology, Saku Central Hospital Advanced Care Center, Saku, Japan; 2Endoscopy, Saku Central Hospital Advanced Care Center, Saku, Japan; 3Gastroenterology, Kameda Medical Center, Kamogawa, Japan; 4 Gastroenterology, Niigata University Medical and Dental Hospital, Niigata, Japan; 5Gastroenterology, Teine Keijinkai Hospital, Sapporo, Japan; 6Gastroenterology, Tottori Municipal Hospital, Tottori, Japan; 7 Gastroenterology, University of Miyazaki, Miyazaki, Japan; 8Digestive Disease and Life-style Related Disease, Kagoshima University School of Medical and Dental Sciences, Kagoshima, Japan; 9Gastroenterology, Nara city hospital, Nara, Japan; 10Gastroenterology, Tokyo Metropolitan Cancer Detection Center, Hutyu, Japan; 11Gastroenterology, Tokushima Red Cross Hospital, Komatsushima, Japan Background: The usefulness of NBI magnified endoscopy (NBI-ME) in diagnosing histological type (HT) of gastric cancer (GC) is unclear. Objective: The aim of this study is to evaluate the diagnostic accuracy for HT of GC by white light endoscopy (WL), NBI-ME and NBI-ME with acetic acid (NBI-AA). Design: Multicenter prospective study (UMIN 000006042) Materials: Depressed-type GCs resected by ESD from Aug. 2011 to Jul. 2014 in 10 institutes were prospectively enrolled in the study. 221 cases were analyzed whose point by point cross-evaluation of ME and histology was possible. Methods: Endoscopic diagnosis: A 3mm area in oral edge of the lesion was selected as a target area (TA) to diagnose HT. Two marks were placed between the TA to compare endoscopic and histological findings. At first, the HT of TA was diagnosed by WL, followed by NBI-ME and NBI-AA. The HT was classified into well (wel), moderately (mod) and poorly (poor) differentiated type. In WL, homogeneous red or whitish lesions, strong or spotted red lesions and undemarcated whitish lesions were diagnosed as wel, mod and poor, respectively. NBI-ME findings were classified based on vascular and surface patterns. Vascular pattern was diagnosed based on vascular networks (NW) and irregularity. If NW was present, HT was diagnosed as wel. If NW was absent, it was diagnosed based on vascular irregularity. Surface patterns were grouped into pit, villous and unclear pattern. When pit pattern was identified, HT was diagnosed as wel or mod based on irregularity. Villous pattern was subgrouped into villi, micro-villi and fusioned villi. Villi and micro-villi was diagnosed as wel and mod, respectively. In case of fusioned villi and unclear pattern, HT was diagnosed based on vascular irregularity. In NBI-AA, HT was diagnosed based on surface patterns alone. When the surface pattern was unclear, it was diagnosed as poor. Pathological diagnosis: An expert pathologist diagnosed the HT of TA. Result: Histological types of target areas were wel, mod and poor in 166, 40 and 15 cases, respectively. The sensitivity of wel, mod and poor by WL, NBI-ME and NBI-AA were 99.4% (165/166), 89.6% (149/166) and 94.6% (157/166) in wel, 0% (0/ 40), 20% (8/40) and 12.5% (5/40) in mod and 60% (9/15), 60% (9/15) and 60% (9/15) in poor, respectively. There were no significant differences. Sub-analysis: The diagnostic accuracy by surface pattern in NBI-ME was 100% (20/20) in pit pattern, 78.9% (120/152) in villous pattern and 53.1% (26/49) in unclear pattern. And NBI-AA changed these diagnostic accuracy 100% (20/20), 78.3% (119/152) and 65.3% (32/49) respectively. While the diagnostic accuracy by unclear pattern in NBI-ME was low compared to other surface patterns, NBI-AA improved it from 53.1% to 65.3%. Conclusion: NBI-AA is useful for histological diagnosis of gastric cancers when surface pattern is unclear in NBI-ME.
Mo1551 Use of Optical Coherence Tomography (OCT) in the Evaluation of Gastric Lesions Ming-Ming Xu*, Stephen M. Lagana, Amrita Sethi Gastroenterology, Columbia University, New York City, NY Background & Aims: Optical coherence tomography (OCT) is a light-based imaging modality that allows high resolution, microscopic level cross-sectional imaging of the mucosa of the gastrointestinal tract during endoscopy (Huang 1991). It has been described in the evaluation of Barrett’s esophagus and colonic polyps for identifying areas of dysplasia in-vivo during endoscopy (Das 2001, Pfau 2003). To date however, there have been no studies describing the imaging characteristics of OCT in the stomach. The aim of this study was to describe OCT findings when imaging a range of gastric mucosal lesions and correlate these images with histopathology. Method: Between July 2014 to October 2014 patients referred for endoscopic submucosal dissection (ESD) for a suspicious appearing gastric lesion or prior biopsy showing LGD underwent volumetric laser endomicroscopy (Nvision VLE imaging system, Nine Point Medical) imaging of the stomach during their endoscopy. The Nvision VLE system is a commercially available OCT device with an axial resolution of 7mm and image depth of 3mm. VLE images of the gastric lesion(s) were retrospectively paired with the histopathology of each resected specimens to correlate VLE findings with the associated histology ranging from gastric mucosa with intestinal metaplasia
AB462 GASTROINTESTINAL ENDOSCOPY Volume 81, No. 5S : 2015
www.giejournal.org
Abstracts
(IM), low grade dysplasia (LGD), high grade dysplasia (HGD), to submucosal tumor. Results: Five patients underwent OCT imaging with the VLE system using a 20mm balloon. All exams were technically successful. A total of 80 VLE-biopsy paired images were retrospectively reviewed by the investigators and a GI pathologist. Patient demographics, endoscopic and endosonographic findings, VLE findings, and histopathology are detailed in Table 1. The following types of lesions were visualized: normal gastric mucosal with focal IM, LGD, HGD and neuroendocrine tumor. VLE images of normal gastric epithelium demonstrates alternating areas of high and lower reflectivity (or scattering) resulting in a stippled appearance of the mucosal surface with “pit and crypt” architecture. Both LGD and HGD results in a loss of pit and crypt architecture, higher surface reflectivity (due to increased nuclear to cytoplasmic ratio in dysplastic tissue) and heterogeneous appearence of the mucosal layer. In the presence of submucosal tumor, the dense tumor infiltration is seen on VLE as high depth penetration with more defined layering differentiating the mucosal and submucosal layers. Conclusion: OCT images of the stomach are distinctive and notably different from the well-defined architecture of the esophagus. This small series demonstrates circumferential OCT imaging is feasible in the stomach and may have a role in the evaluation of suspicious gastric lesions. Further study is needed to determine findings that may be more specific to differentiating degrees of dysplasia and carcinoma. Table 1. Characteristics of gastric lesions evaluated by VLE Case No
VLE balloon size
Age
Sex
Abdominal symptoms
Endoscopic findings
1
69
F
Diarrhea
Nodularity, erythema in antrum
No visible lesion noted
20mm
2
69
F
Pain
Gastric antral ulcer
Not performed
20mm
3
67
F
Pain, bloating
Mass with oozing, ulceration on greater curvature
Intramucosal hypoechoic 10mm lesion
20mm
4
68
F
Pain
Two ulcerated nodules gastric cardia
Submucosal hypoechoic 1.7cm x 0.7cm lesion, 0.5x0.8cm satellite lesion
20mm
5
81
F
Early satiety, weight loss
Thickened folds in antrum
Not performed
20mm
EUS findings
VLE findings
Pathology
Loss of pit and crypt architecture, subtle layering, low scattering mucosal structures Loss of pit and crypt architecture, high surface reflectivity with heterogeneous texture Loss of pit and crypt architecture, high surface reflectivity, clustering of dilated mucosal and submucosal structures Loss of pit and crypt architecture, heterogeneous scattering, dense demarcation between mucosa and low-scattering submucosal structure Loss of pit and crypt architecture. Homogenous scattering.
Gastric mucosa, focal IM
LGD
Part A: adenoma with LGD Part B: adenoma with focal HGD
Well differentiated neuroendocrine tumor, low grade (carcinoid), T2 invades muscularis propria
Gastric mucosa with IM
tivity. (C) Gastric adenoma with LGD and HGD presents as a loss of pit and crypt architecture with a proliferation of clustered, dilated atypical glands. (D) Finally, a neuroendocrine tumor of the stomach presents as a loss of pit and crypt architecture with a distinct, low scattering submucosal structure, clearly delineated from surrounding tissue.
Mo1552 A Proof-of-Principle Assessment of the Role of Light-NBI Endoscopy to Assess High-Risk Phenotype for Gastric Cancer: Endoscopy Replaces Histology? Jorge Lage*3, Pedro Pimentel-Nunes3, Pedro C. Figueiredo1, Diogo Libânio3, Iolanda Ribeiro2, Manuel Jácome4, Luís Afonso4, Mario Dinis-Ribeiro3 1 Gastroenterology, Hospital Garcia da Orta, Almada, Portugal; 2 Gastroenterology, Centro Hospitalar de Vila Nova de Gaia, Vila Nova de Gaia, Portugal; 3Gastroenterology, Portuguese Oncology Institute of Porto, Porto, Portugal; 4Pathology, Portuguese Oncology Institute of Porto, Porto, Portugal Introduction: Patients with extensive intestinal metaplasia and/or those OLGIM stages III-IV merit surveillance leading to early diagnosis of gastric cancer and improvement of patients survival (Dinis-Ribeiro M 2012). High-resolution NBI has been shown to accurately determine the presence of IM at specific sites (PimentelNunes P 2012). We hypothesized that the new Olympus system could be used to estimate extensive intestinal metaplasia (eIM) and it could replace or at least be used to target biopsies. Therefore we aimed at assessing the reliability and accuracy of the new Olympus system to assess the presence of eIM on a per-patient basis. Methods: A consecutive series of 25 patients (mean age 59.6 years old, 40% male) without known precancerous conditions or lesions in the stomach were submitted to upper gastrointestinal endoscopy using the 190 series of Olympus. Still images recorded using non-magnified pictures with wight-light endoscopy (WLE) of the antrum, angle, corpus lesser curvature in retroversion and greater curvature in anteversion (4 images); at the same positions with light NBI (L-NBI) (4 different images); and 5 magnified images (MAG) using close focus at antrum (lesser and greater curvature), angle and corpus (lesser and greater curvature). With two different levels of expertise, 6 endoscopists were asked to independently and blinded to histology record their suggested diagnosis of the extensive IM according to each technique (WLE only and/or L-NBI; without or with magnified observations). All images were randomly shown between observations. Biopsies from the antrum, incisura and corpus were sent in different vials according to guidelines (MAPS) and OLGIM used as gold standard. Results: The prevalence of OLGIM III/IV stages and eIM in this sample was 28% and 40% of patients, respectively (whereas 40% had no IM in endoscopic biopsies). With 21% of images considered to be low quality, 4/6 endoscopists increased their certainty by using WLE+L-NBI+MAG view vs WLE to describe findings and 3/6 increased the global accuracy to estimate OLGIM status and eIM. The accuracy to identify those with eIM is optimized in all observers comparing WLE with the use of L-NBI and magnified view vs WLE (LR+ from 3,33 to 6,72; LR- from 0,58 to 0,29 for OLGIM III/IV). Also, the inter-observer reliability increased both in trainees and in experts. Conclusions: In this report, for the first time the reliability of endoscopic features for extension of IM is described. Moreover, we conclude that with proper training endoscopic assessment of gastric mucosa can adequately select 3/4 of patients that would merit surveillance (according to OLGIM grade) if biopsies have been performed and that endoscopy alone can detect up to 90% of those with eIM. Further validation larger cohorts are crutial to understand the precise accuracy.
Summary of results
Figure 1. VLE findings in normal and diseased gastric tissue. (A) Normal gastric tissue has a regular foveolar appearance on VLE, with characteristic ‘pits and crypts’ presenting as superficial striations in the image. (B) In focal IM with LGD, the corresponding VLE image shows a disruption to the normal ‘pit and crypt’ architecture, along with increased surface reflec-
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Certainty Global proportion of agreement with histology Trainees Experts Global accuracy OLGIM Trainees Experts Sensitivity OLGIM III/IV False+ rateOLGIM III/IV Interobserver reliability (wK (95%CI)) Trainees Experts
WLE (% (range))
L-NBI (% (range))
WLE+L-NBI (% (range))
WLE+L-NBI+MAG (% (range))
45 (20-56) 60 (48-64)
49 (20-76) 63 (48-76)
50 (36-60) 65 (56-72)
64 (48-88) 73 (56-92)
59 (48-64) 61 (60-64) 58 (44-72)
56 (48-60) 69 (56-76) 59 (48-76)
61 (56-68) 68 (60-72) 61 (52-76)
63 (46-68) 83 (76-92) 64 (52-76)
53 (44-60) 63 (56-72) 50 (29-86) 15 (4-44) 0,42 (0,26-0,62)
53 (48-60) 64 (52-76) 62 (14-100) 10 (0-28) 0,55 (0,39-0,73)
57 (52-60) 65 (56-76) 62 (29-86) 13 (4-28) 0,50 (0,32-0,68)
55 (52-56) 75 (72-76) 74 (43-86) 11 (0-25) 0,60 (0,43-0,76)
0,33 (0,09-0,59) 0,61 (0,39-0,79)
0,41 (0,16-0,65) 0,61 (0,39-0,79)
0,40 (0,15-0,64) 0,70 (0,50-0,84)
0,44 (0,19-0,67) 0,78 (0,62-0,89)
Volume 81, No. 5S : 2015 GASTROINTESTINAL ENDOSCOPY AB463