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Su2008 Potential Role for Volumetric Laser Endomicroscopy in Barrett's Esophagus
Su2009 Ultrahigh Speed Micromotor Optical Coherence Tomography Enables Improved Access, Image Quality, and Maneuverability in Upper and Lower Endoscopy Michael G. Giacomelli, Tsung-Han Tsai, Osman O. Ahsen, Hsiang-Chieh Lee, Kaicheng Liang, Zhao Wang, Marisa Figueiredo, Qin Huang, Benjamin Potsaid, James G. Fujimoto, Hiroshi Mashimo BACKGROUND: Commercially available Optical Coherence Tomography (OCT) systems based on proximal rotation are unsuitable for applications that require longer imaging catheters to be passed through sharp bends as well as applications that require retroflexion of the endoscope. This limits the clinical utility of OCT in emerging applications such as the identification of dysplasia in the gastric cardia, and the investigation of the architectural features of IBD in the ascending colon and terminal ileum. In this study, we present an ultrahigh speed 3D-OCT system utilizing a micromotor imaging probe to investigate areas of the GI tract where access has previously been limited. The micromotor imaging probe enables reliable volumetric imaging by eliminating non-uniform rotation due to proximal actuation and bending of the probe. Representative volumetric OCT images over the terminal ileum are presented to demonstrate the clinical utility of the newly developed system. METHODS: The study was performed at the VA Boston Healthcare System (VABHS) under a study protocol approved by the VABHS, Harvard Medical School and M.I.T. Imaging was performed with a prototype 3D-OCT system with an imaging speed (axial scan rate) of 600 kHz, approximately 10 times faster than commercially available OCT imaging systems. Distal scanning of the imaging was performed using a micromotor attached to the distal end of the OCT probe. The probe was passed through the accessory channel of an Olympus double channel endoscope (GIF-2TH180) to allow coregistration of images with biopsies. RESULTS: We demonstrate 3D-OCT with distally actuated imaging, enabling volumetric imaging over regions of the GI tract that are inaccessible with commercial OCT systems. For example, Fig. 1(A, B) demonstrate en face OCT image planes of the terminal ilium at two different depths beneath the tissue surface. Fig. 1(C) presents a cross-sectional OCT image indicated in Fig. 1(A) showing comprehensive imaging down through the villi to the underlying muscularis mucosa. Fig. 1(D) shows white light colonoscopy imaging of the terminal ileum during OCT imaging. Finally, Fig. 1(E) shows histology from the corresponding biopsy of the imaging site. CONCLUSIONS: This study demonstrates the feasibility of the new ultrahigh speed 3D-OCT system in imaging the parts of the GI tract that require long catheter lengths and high maneuverability, which are not possible with current commercial OCT systems. By eliminating the need to transmit torque through the entire endoscope, proximal actuation enables imaging beyond tight bends as well as applications that require retroflexion of the endoscope. Due to these unique advantages, this system has the potential to greatly improve the clinical utility of OCT imaging. ACKNOWLEDGEMENT: NIH 5R01-CA075289-16, R44CA101067-06, AFOSR FA9550-12-1-0499, and FA9550-10-1-0551.
Figure 1. Representative en face OCT images and co-registered microvascular map of the rectum and anal canal. Fig. 1C shows the superposed en face OCT image of the rectum exhibiting a regular crypt pit pattern (A, gray color scale) with mesh type vascular network (B, red color scale), suggesting the vasculatures identified are mostly from the laminar propria surrounding the crypts. Figs. 1(D, E), and (F, G) show the en face OCT images and the corresponding vascular map over the anal canal at different depth levels, respectively. Several prominent vessels can be identified. The imaging depth is (A, B, and C) 150um, (D, E) 280um, and (F, G) 180um beneath the tissue surface. Scale bars: 500um. Su2008 Potential Role for Volumetric Laser Endomicroscopy in Barrett's Esophagus Vani J. Konda, Uzma D. Siddiqui, Shu-Yuan Xiao, Ann Koons, Jerrold R. Turner, Baldeep Pabla, Andres Gelrud, John Hart, Irving Waxman Background: During endoscopic surveillance and treatment in Barrett's esophagus (BE), endoscopists use a combination of imaging tools to help target biopsies and endoscopic mucosal resections in order to diagnose and treat Barrett's associated neoplasia. Identifying subepithelial metaplasia and neoplasia in Barrett's patients has proven challenging. Tools to characterize "buried" disease may allow for improved detection of occult disease. Optical biopsy with Volumetric Laser Endomicroscopy (VLE) is based on optical coherence tomography and may have potential to detect buried disease. This is a pilot study to determine the role of VLE in a center with a referral practice for BE. Methods: Patients with BE presented for surveillance or treatment. Endoscopy was performed with high resolution white light endoscopy (WLE), narrow band imaging (NBI) with and without near focus, and VLE. Tissue acquisition with either endoscopic mucosal resection or biopsy forceps was performed based on endoscopists' discretion. VLE images were obtained and correlated with histology. Results: Eleven patients underwent VLE imaging. Initial diagnosis was intramucosal carcinoma (IMC) in 3 cases, high grade dysplasia (HGD) in 5, low grade dysplasia (LGD) in 3, and non dysplastic Barrett's in 1. Five patients never had previous endotherapy, 3 had undergone radical endoscopic mucosal resection (EMR), and 3 had hybrid therapy of EMR and radiofrequency ablation (RFA). Three cases demonstrated findings that were otherwise occult by WLE or NBI. In one case, a patient was referred with a diagnosis of focal HGD on a random biopsy in long segment BE. VLE detected an area of irregular septated glands that was not appreciated on WLE or NBI. This area was then targeted by EMR and histology found HGD and LGD. In a second case, a patient is referred for short segment BE with HGD. VLE detected endoscopically inapparent subepithelial glands proximal to the squamocolumnar junction. EMR of this area demonstrated low grade dysplasia buried underneath squamous epithelium on histology. In the third case, a patient was in surveillance status post hybrid treatment for BE with IMC with last surveillance endoscopy with biopsies only demonstrating normal squamous epithelium. WLE and NBI were unremarkable. VLE was performed and detected a subepithelial gland, which was targeted using a keyhole biopsy approach. Histology and Alcian blue staining confirmed the presence of buried Barrett's esophagus. Conclusion: VLE has potential in the detection of neoplasia in BE and in the evaluation of subepithelial disease. Further studies are needed to determine the impact on clinical outcome with this technology.
Figure 1: A) En face surface of the terminal ileum. B) En face layer 300 μm below the terminal ileum surface with visible villi (arrows). C) Cross-sectional view of the terminal ileum. D) White light endoscopy view of the tissue in A-C. E) Biopsy performed of the imaging site. Scale bars: 1000 μm. Su2010 Near Infrared Labeling and Detection of Enteric Nerves: Tracking of Differentiating Neural Progenitor Cells and Tissue Innervation Aaron M. Mohs, Robert R. Gilmont, Shreya Raghavan, Sita Somara, Frank C. Marini, Shanthi Srinivasan, Khalil N. Bitar Background: Non-destructive imaging modalities to monitor transplanted tissues are of particular importance in regenerative medicine. Monitoring stem cells in complex and deep tissue limits the ability to elucidate mechanisms of repair. In this regard, our approach is to develop near infrared (NIR) fluorescent methodology to label and detect progenitor cell populations in a multicellular tissue construct in vivo. Objective: We have focused on bioengineered innervated internal anal sphincter (IAS) smooth muscle constructs as a model system to test the strengths of this approach. Our studies aimed to demonstrate the equivalence in physiology between NIR labeled and unlabeled bioengineered IAS constructs. Methods: pLenti-iRFP was generated by amplification of iRFP from plasmid "piRFP" (Addgene #31857). The enteric neuronal progenitor cell line, IM-FEN cells were transduced with Lenti-iRFP yielding NIR-labeled IM-FEN cells (IM-FEN-iRFP). 25mM biliverdin was used to image NIR labeled cells using fluorescence microscopy (Cy5.5) and a CRI extended range spectral camera. Neuronal differentiation was studied by βIII Tubulin and Vasoactive Intestinal Peptide (VIP) labeling. Innervated IAS constructs were bioengineered using IAS circular smooth muscle cells and IM-FEN cells or IM-FEN-iRFP cells. Force generation was used to study IAS physiology. Results: Fluorescence microscopy of IM-FEN-iRFP cells shows bright and stable NIR fluorescence. Untransduced IM-FEN cells have no detectable NIR signal. IM-FEN-iRFPs develop neuronal projections within 5 days of coincubation with IAS, and express equivalent levels of βIII Tubulin. The presence of differentiated VIP-ergic neurons was also equivalent between the transduced and untransduced IM-FENs. Bioengineered IAS constructs generated spontaneous basal tone. Constructs relaxed in response to VIP in a tetrodotoxin-sensitive manner, indicating the presence of differentiated VIP-ergic neurons.
Histology demonstrated a buried gland (A) corresponding to the subepithelial glandular structure seen on volumetric laser endomicroscopy (B). Alcian blue staining confirmed the presence of Barrett's esophagus under the squamous epithelium.
S-521
AGA Abstracts
AGA Abstracts
as well as microvascular features of GI pathologies without the need for exogenous contrast agents. Compared with NBI, OCT microangiography can provide a full three dimensional, depth resolved view of the microvascular network and is not limited to visualizing surface features. These capabilities should facilitate the detection of GI pathologies and the assessment of treatment efficacy. ACKNOWLEDGEMENT: NIH 5R01-CA075289-16, R44-CA10106706, AFOSR FA9550-12-1-0499, and FA9550-10-1-0551.
Figure 1. Representative en face OCT images and co-registered microvascular map of the rectum and anal canal. Fig. 1C shows the superposed en face OCT image of the rectum exhibiting a regular crypt pit pattern (A, gray color scale) with mesh type vascular network (B, red color scale), suggesting the vasculatures identified are mostly from the laminar propria surrounding the crypts. Figs. 1(D, E), and (F, G) show the en face OCT images and the corresponding vascular map over the anal canal at different depth levels, respectively. Several prominent vessels can be identified. The imaging depth is (A, B, and C) 150um, (D, E) 280um, and (F, G) 180um beneath the tissue surface. Scale bars: 500um. Su2008 Potential Role for Volumetric Laser Endomicroscopy in Barrett's Esophagus Vani J. Konda, Uzma D. Siddiqui, Shu-Yuan Xiao, Ann Koons, Jerrold R. Turner, Baldeep Pabla, Andres Gelrud, John Hart, Irving Waxman Background: During endoscopic surveillance and treatment in Barrett's esophagus (BE), endoscopists use a combination of imaging tools to help target biopsies and endoscopic mucosal resections in order to diagnose and treat Barrett's associated neoplasia. Identifying subepithelial metaplasia and neoplasia in Barrett's patients has proven challenging. Tools to characterize "buried" disease may allow for improved detection of occult disease. Optical biopsy with Volumetric Laser Endomicroscopy (VLE) is based on optical coherence tomography and may have potential to detect buried disease. This is a pilot study to determine the role of VLE in a center with a referral practice for BE. Methods: Patients with BE presented for surveillance or treatment. Endoscopy was performed with high resolution white light endoscopy (WLE), narrow band imaging (NBI) with and without near focus, and VLE. Tissue acquisition with either endoscopic mucosal resection or biopsy forceps was performed based on endoscopists' discretion. VLE images were obtained and correlated with histology. Results: Eleven patients underwent VLE imaging. Initial diagnosis was intramucosal carcinoma (IMC) in 3 cases, high grade dysplasia (HGD) in 5, low grade dysplasia (LGD) in 3, and non dysplastic Barrett's in 1. Five patients never had previous endotherapy, 3 had undergone radical endoscopic mucosal resection (EMR), and 3 had hybrid therapy of EMR and radiofrequency ablation (RFA). Three cases demonstrated findings that were otherwise occult by WLE or NBI. In one case, a patient was referred with a diagnosis of focal HGD on a random biopsy in long segment BE. VLE detected an area of irregular septated glands that was not appreciated on WLE or NBI. This area was then targeted by EMR and histology found HGD and LGD. In a second case, a patient is referred for short segment BE with HGD. VLE detected endoscopically inapparent subepithelial glands proximal to the squamocolumnar junction. EMR of this area demonstrated low grade dysplasia buried underneath squamous epithelium on histology. In the third case, a patient was in surveillance status post hybrid treatment for BE with IMC with last surveillance endoscopy with biopsies only demonstrating normal squamous epithelium. WLE and NBI were unremarkable. VLE was performed and detected a subepithelial gland, which was targeted using a keyhole biopsy approach. Histology and Alcian blue staining confirmed the presence of buried Barrett's esophagus. Conclusion: VLE has potential in the detection of neoplasia in BE and in the evaluation of subepithelial disease. Further studies are needed to determine the impact on clinical outcome with this technology.
Figure 1: A) En face surface of the terminal ileum. B) En face layer 300 μm below the terminal ileum surface with visible villi (arrows). C) Cross-sectional view of the terminal ileum. D) White light endoscopy view of the tissue in A-C. E) Biopsy performed of the imaging site. Scale bars: 1000 μm. Su2010 Near Infrared Labeling and Detection of Enteric Nerves: Tracking of Differentiating Neural Progenitor Cells and Tissue Innervation Aaron M. Mohs, Robert R. Gilmont, Shreya Raghavan, Sita Somara, Frank C. Marini, Shanthi Srinivasan, Khalil N. Bitar Background: Non-destructive imaging modalities to monitor transplanted tissues are of particular importance in regenerative medicine. Monitoring stem cells in complex and deep tissue limits the ability to elucidate mechanisms of repair. In this regard, our approach is to develop near infrared (NIR) fluorescent methodology to label and detect progenitor cell populations in a multicellular tissue construct in vivo. Objective: We have focused on bioengineered innervated internal anal sphincter (IAS) smooth muscle constructs as a model system to test the strengths of this approach. Our studies aimed to demonstrate the equivalence in physiology between NIR labeled and unlabeled bioengineered IAS constructs. Methods: pLenti-iRFP was generated by amplification of iRFP from plasmid "piRFP" (Addgene #31857). The enteric neuronal progenitor cell line, IM-FEN cells were transduced with Lenti-iRFP yielding NIR-labeled IM-FEN cells (IM-FEN-iRFP). 25mM biliverdin was used to image NIR labeled cells using fluorescence microscopy (Cy5.5) and a CRI extended range spectral camera. Neuronal differentiation was studied by βIII Tubulin and Vasoactive Intestinal Peptide (VIP) labeling. Innervated IAS constructs were bioengineered using IAS circular smooth muscle cells and IM-FEN cells or IM-FEN-iRFP cells. Force generation was used to study IAS physiology. Results: Fluorescence microscopy of IM-FEN-iRFP cells shows bright and stable NIR fluorescence. Untransduced IM-FEN cells have no detectable NIR signal. IM-FEN-iRFPs develop neuronal projections within 5 days of coincubation with IAS, and express equivalent levels of βIII Tubulin. The presence of differentiated VIP-ergic neurons was also equivalent between the transduced and untransduced IM-FENs. Bioengineered IAS constructs generated spontaneous basal tone. Constructs relaxed in response to VIP in a tetrodotoxin-sensitive manner, indicating the presence of differentiated VIP-ergic neurons.
Histology demonstrated a buried gland (A) corresponding to the subepithelial glandular structure seen on volumetric laser endomicroscopy (B). Alcian blue staining confirmed the presence of Barrett's esophagus under the squamous epithelium.
S-521
AGA Abstracts
AGA Abstracts
as well as microvascular features of GI pathologies without the need for exogenous contrast agents. Compared with NBI, OCT microangiography can provide a full three dimensional, depth resolved view of the microvascular network and is not limited to visualizing surface features. These capabilities should facilitate the detection of GI pathologies and the assessment of treatment efficacy. ACKNOWLEDGEMENT: NIH 5R01-CA075289-16, R44-CA10106706, AFOSR FA9550-12-1-0499, and FA9550-10-1-0551.