Marisa Figueiredo

Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos)

BACKGROUND Radiofrequency ablation (RFA) is an endoscopic technique used to eradicate Barretts esophagus (BE). However, such ablation can commonly lead to neosquamous epithelium overlying residual BE glands not visible by conventional endoscopy and may evade detection on random biopsy samples. OBJECTIVE To demonstrate the capability of endoscopic 3-dimensional optical coherence tomography (3D-OCT) for the identification and characterization of buried glands before and after RFA therapy. DESIGN Cross-sectional study. SETTING Single teaching hospital. PATIENTS Twenty-six male and 1 female white patients with BE undergoing RFA treatment. INTERVENTIONS 3D-OCT was performed at the gastroesophageal junction in 18 patients before attaining complete eradication of intestinal metaplasia (pre-CE-IM group) and in 16 patients after CE-IM (post-CE-IM group). MAIN OUTCOME MEASUREMENTS Prevalence, size, and location of buried glands relative to the squamocolumnar junction. RESULTS 3D-OCT provided an approximately 30 to 60 times larger field of view compared with jumbo and standard biopsy and sufficient imaging depth for detecting buried glands. Based on 3D-OCT results, buried glands were found in 72% of patients (13/18) in the pre-CE-IM group and 63% of patients (10/16) in the post-CE-IM group. The number (mean [standard deviation]) of buried glands per patient in the post-CE-IM group (7.1 [9.3]) was significantly lower compared with the pre-CE-IM group (34.4 [44.6]; P = .02). The buried gland size (P = .69) and distribution (P = .54) were not significantly different before and after CE-IM. LIMITATIONS A single-center, cross-sectional study comparing patients at different time points in treatment. Lack of 1-to-1 coregistered histology for all OCT data sets obtained in vivo. CONCLUSION Buried glands were frequently detected with 3D-OCT near the gastroesophageal junction before and after radiofrequency ablation.

Effective treatment of chronic radiation proctitis using radiofrequency ablation

Endoscopic argon plasma coagulation and bipolar electrocautery are currently preferred treatments for chronic radiation proctitis, but ulcerations and strictures frequently occur. Radiofrequency ablation (RFA) has been successful for mucosal ablation in the esophagus. Here we report the efficacy of RFA with the BarRx Halo90 system in three patients with bleeding from chronic radiation proctitis. In all cases, the procedure was well tolerated and hemostasis was achieved after 1 or 2 RFA sessions. Re-epithelialization of squamous mucosa was observed over areas of prior hemorrhage. No stricturing or ulceration was seen on follow-up up to 19 months after RFA treatment. Real-time endoscopic optical coherence tomography (EOCT) visualized epithelialization and subsurface tissue microvasculature pre- and post-treatment, demonstrating its potential for follow-up assessment of endoscopic therapies.

Ultrahigh speed endoscopic optical coherence tomography for gastroenterology

We describe an ultrahigh speed endoscopic swept source optical coherence tomography (OCT) system for clinical gastroenterology using a vertical-cavity surface-emitting laser (VCSEL) and micromotor imaging catheter. The system had a 600 kHz axial scan rate and 8 µm axial resolution in tissue. Imaging was performed with a 3.2 mm diameter imaging catheter at 400 frames per second with a 12 µm spot size. Three-dimensional OCT (3D-OCT) imaging was performed in patients with a cross section of pathologies undergoing upper and lower endoscopy. The use of distally actuated imaging catheters enabled OCT imaging with more flexibility, such as volumetric imaging in the small intestine and the assessment of hiatal hernia using retroflex imaging. The high rotational scanning stability of the micromotor enabled 3D volumetric imaging with micron scale volumetric accuracy for both en face OCT and cross-sectional imaging, as well as OCT angiography (OCTA) for 3D visualization of subsurface microvasculature. The ability to perform both structural and functional 3D OCT imaging in the GI tract with microscopic accuracy should enable a wide range of studies and enhance the sensitivity and specificity of OCT for detecting pathology.

Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett's Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography.

Two main nonsurgical endoscopic approaches for ablating dysplastic and early cancer lesions in the esophagus have gained popularity, namely, radiofrequency ablation (RFA) and cryospray ablation (CSA). We report a uniquely suited endoscopic and near-microscopic imaging modality, three-dimensional (3D) optical coherence tomography (OCT), to assess and compare the esophagus immediately after RFA and CSA. The maximum depths of architectural changes were measured and compared between the two treatment groups. RFA was observed to induce 230~260 μm depth of architectural changes after each set of ablations over a particular region, while CSA was observed to induce edema-like spongiform changes to ~640 μm depth within the ablated field. The ability to obtain micron-scale depth-resolved images of tissue structural changes following different ablation therapies makes 3D-OCT an ideal tool to assess treatment efficacy. Such information could be potentially used to provide real-time feedback for treatment dosing and to identify regions that need further retreatment.

Volumetric Mapping of Barrett's Esophagus and Dysplasia With en face Optical Coherence Tomography Tethered Capsule.

Volumetric Mapping of Barrett’s Esophagus and Dysplasia With en face Optical Coherence Tomography Tethered Capsule

Ultrahigh-speed endoscopic optical coherence tomography and angiography enables delineation of lateral margins of endoscopic mucosal resection: a case report

Creative Commons Non Commercial CC BY-NC: This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (http://www.creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage). Introduction Endoscopic mucosal resection (EMR) is a common technique for resecting dysplastic lesions in Barrett’s esophagus (BE), stomach, and colon,1 but precise delineation of dysplastic margins before resection and verification of complete removal after resection remain challenging.2,3 Endoscopic optical coherence tomography (OCT) enables three-dimensional visualization of tissue microstructure and is commercially available as Volumetric Laser Endomicroscopy (NinePoint Medical, Bedford, MA, USA).4,5 We recently developed an ultrahigh-speed endoscopic OCT system which operates more than 10 times faster than commercial instruments, generating volumetric images with higher transverse resolution and voxel density.6,7 This allows visualization of depth-resolved en face mucosal and microvascular patterns (OCT angiography [OCTA]), in addition to cross-sections. A recent study with 32 patients reported 94% sensitivity and 69% specificity for identifying dysplasia on blinded assessment of OCTA images.8 This current report demonstrates the clinical utility of probe-based, ultrahigh-speed endoscopic OCT and OCTA for assessing a dysplastic lesion at the gastroesophageal junction (GEJ), its lateral margins before and immediately after EMR, and at 2-month follow up.

W1054 Radiofrequency Ablation with BARRx Halo90 Effectively Treated Chronic Radiation Proctitis As Confirmed with Endoscopic Three-Dimensional Optical Coherence Tomography

BACKGROUND: Chronic radiation proctitis (CRP) is a long-term complication of pelvic radiotherapy. Argon plasma coagulation and bipolar electrocautery are current hemostatic treatments for CRP, but ulcerations, re-bleeding and strictures frequently occur. Endoscopic three-dimensional optical coherence tomography (3D-OCT) was used for follow-up assessment of RFA treatment to evaluate the presence of neo-squamous epithelium and subsurface vessels. METHODS: Five patients with bleeding from CRP were treated with RFA using the BARRXHalo90 system. Two patients previously failed therapy with argon plasma coagulation, and one patient previously failed therapy with electocautery. Patients were imaged with standard endoscopy and 3D-OCT before and after the RFA treatment. 3D-OCT volumes with less than 10 μm resolution were obtained with a spiral-scanning catheter over an 8 x 18 x 1.8 mm region in 20 seconds. RESULTS: In all cases, the procedure was well-tolerated and hemostasis was achieved after 1 or 2 RFA sessions. Excellent re-epithelialization and absence of ulcerations or strictures was observed following the RFA treatment up to 19 months. Ectatic blood vessels observed over areas of prior hemorrhage were effectively removed. Vascular structure could be differentiated from focal glands or cysts by sectioning through the volumetric data set and tracking vessel patterns. Follow-up images over visible ablation area with neo-squamous layer showed no evidence of underlying large ectatic vessels. CONCLUSIONS: 3D-OCT provides large-area volumetric subsurface imaging of tissue microstructure In-Vivo. 3D-OCT, used in conjunction with standard endoscopy, is a uniquely suited modality for assessing treatment of CRP, especially since excisional biopsies must be avoided in these relatively ischemic regions which are prone to re-bleeding and heal poorly.

Assessment of Barrett’s esophagus and dysplasia with ultrahigh-speed volumetric en face and cross-sectional optical coherence tomography

BACKGROUND  This study aimed to evaluate the use of ultrahigh-speed volumetric en face and cross-sectional optical coherence tomography (OCT) with micromotor catheters for the in vivo assessment of Barretts esophagus and dysplasia. METHODS  74 OCT datasets with correlated biopsy/endoscopic mucosal resection histology (49 nondysplastic Barretts esophagus [NDBE], 25 neoplasia) were obtained from 14 patients with Barretts esophagus and a history of dysplasia and 30 with NDBE. The associations between irregular mucosal patterns on en face OCT, absence of mucosal layering, surface signal > subsurface, and > 5 atypical glands on cross-sectional OCT vs. histology and treatment history were assessed by three blinded readers. RESULTS  Atypical glands under irregular mucosal patterns occurred in 75 % of neoplasia (96 % of treatment-naïve neoplasia) vs. 30 % of NDBE datasets (43 % of short- and 18 % of long-segment NDBE). Mucosal layering was absent in 35 % of neoplasia and 50 % of NDBE datasets, and surface signal > subsurface occurred in 29 % of neoplasia and 30 % of NDBE datasets. CONCLUSIONS  Atypical glands under irregular mucosal patterns are strongly associated with neoplasia, suggesting potential markers for dysplasia and a role in pathogenesis.

Endoscopic optical coherence tomography and angiography for gastroenterology applications

Endoscopic optical coherence tomography (OCT) angiography enables volumetric coregistered architectural and microvasculature imaging of the human gastrointestinal tract in vivo. In this talk, we will discuss technical advances and clinical gastroenterology applications with the endoscopic OCT angiography technique.

Su2007 Novel Ultrahigh Speed Optical Coherence Tomography System and Micromotor Imaging Probe for Investigating Microvasculature in the Gastrointestinal Tract

G A A b st ra ct s histology. Methods: BE patients with and without early neoplasia underwent endoscopic resection (ER) of areas marked in-vivo with electrocoagulation markers (ECM). Subsequently ER specimens underwent additional ex-vivo marking with several different markers (ink, pin, ECM) followed by ex-vivo VLE scanning. Tissue blocks were carefully sectioned guided by the placed markers. After further histological processing a histopathology slide was sectioned from each block. When necessary, extensive sectioning of tissue blocks was performed in order to visualize all markers that were included in the tissue block on histology. All histopathology and VLE slides were evaluated by 2 researchers and considered a match if a) ≥ 2 markers were visible on both modalities and b) mucosal patterns aside from these markers matched on both histology and VLE. All slides were evaluated by an expert BE pathologist. Results: From 16 ER specimens (overall diagnosis: 7 non-dysplastic BE, 9 dysplastic BE (1 LGD, 4 HGD, 4 EAC)) 120 tissue blocks were sectioned of which 57 contained multiple markers and thus could potentially be matched with VLE. Based on several combinations of these markers in total 14 histology-VLE matches could ultimately be constructed. Markers that achieved the best yield of matches respectively were: invivo placed ECMs (8 matches with 12 markers), pins (7 with 11), and ink (4 with 5). Histopathological evaluation was not hindered by marker use. In this pilot study the last 6 ER specimens yielded 9/14 matches demonstrating a clear learning curve due to methodological improvements in marker placement and tissue block sectioning. Conclusion: One-to-one correlation of VLE and histology is complex but feasible. The groundwork laid in this study will provide high-quality histology-VLE correlations that will allow further research on VLE structures and VLE features of early neoplasia in BE.