Xiao-Meng Gu

Classification of inflammation activity in ulcerative colitis by confocal laser endomicroscopy.

OBJECTIVES:The assessment of inflammation activity in ulcerative colitis (UC) includes endoscopy and histology. Confocal laser endomicroscopy (CLE) combines real-time endoscopy and histology. This study was aimed at evaluating the application of CLE in the assessment of inflammation activity in UC.METHODS:In total, 73 consecutive patients with UC who visited Qilu Hospital for colonoscopy surveillance underwent CLE. Inflammation activity was first assessed by the colonoscopy Baron score, then by CLE with a 4-grade classification of crypt architecture, as well as by analysis of microvascular alterations and fluorescein leakage. Targeted biopsy samples were taken for histological analysis. Stored CLE images were subjected to post-CLE objective assessment.RESULTS:Both assessment of crypt architecture and fluorescein leakage with CLE showed good correlations with histological results (Spearmans rho, both P<0.001). CLE seemed to be more accurate than conventional white-light endoscopy for evaluating macroscopical normal mucosa. More than half of the patients with normal mucosa seen on conventional white-light endoscopy showed acute inflammation on histology, whereas no patients with normal mucosa or with chronic inflammation seen on CLE showed acute inflammation on histology. Assessment of microvascular alterations by CLE showed good correlation with histological findings (P<0.001). On post-CLE objective assessment, subjective architectural classifications were supported by the number of crypts per image (P<0.001) but not fluorescein leakage results by gray scale (P=0.194).CONCLUSIONS:CLE is reliable for real-time assessment of inflammation activity in UC. Crypt architecture, microvascular alterations, and fluorescein leakage are promising markers in CLE evaluation.

Diagnostic value of confocal laser endomicroscopy for gastric superficial cancerous lesions

Background The identification of gastric superficial cancerous lesions based on conventional white-light endoscopy (WLE) is challenging, and histological analysis remains the ‘gold standard’ for the final diagnosis. Confocal laser endomicroscopy (CLE) can provide in vivo histological observation without the need for biopsy. Objective To develop and evaluate CLE imaging criteria for gastric superficial cancerous lesions and to compare the diagnostic value of real-time integrated CLE (iCLE) and WLE alone in distinguishing gastric superficial cancerous lesions. Design Prospective study. Setting Qilu Hospital, Shandong University, Jinan, China. Patients A total of 182 patients were enrolled into phase I and 1786 patients were enrolled into phase II. Interventions CLE images were blindly evaluated after endoscopy in phase I, and real-time iCLE diagnosis during endoscopy was compared with WLE diagnosis by using histopathology as a gold standard in phase II. Main outcome measurements The validity and reliability of the CLE diagnosis for identifying gastric superficial cancerous lesions. Results Off-line CLE diagnosis for early gastric cancers had a high sensitivity (88.1%) and specificity (98.6%). When the two-tiered CLE classification of non-cancerous lesions and cancer/high-grade intraepithelial neoplasia (HGIN) lesions was introduced, CLE diagnosis led to a higher sensitivity (90.2%) and specificity (98.5%) (phase I). Real-time iCLE diagnosis had a higher sensitivity (88.9%), specificity (99.3%) and accuracy (98.8%) for gastric superficial cancer/HGIN lesions than WLE diagnosis (sensitivity, 72.2%; specificity, 95.1%; and accuracy, 94.1%) (p<0.05) (phase II). Limitations This was a single-centre study. Conclusions CLE can be used to identify gastric superficial cancer/HGIN lesions with high validity and reliability.

Differentiation of colonic polyps by confocal laser endomicroscopy.

BACKGROUND AND STUDY AIM The real-time identification and removal of adenomas is a cost-effective strategy to improve the prognosis of colorectal cancer. Confocal laser endomicroscopy (CLE) could provide real-time histological-level observation. We aimed to evaluate the efficacy of CLE diagnosis using a simple classification system that differentiates adenomas from non-neoplastic polyps with intravenous fluorescein staining alone. PATIENTS AND METHODS An endoscope integrated confocal laser microscopy system was used in this study. CLE images of 35 colonic polyps, including 15 hyperplastic polyps and 20 adenomas confirmed by histology, were first evaluated to develop criteria for diagnosis of neoplastic and non-neoplastic polyps. The diagnostic criteria included goblet cell depletion, villous architecture, and microvascular alterations. We then performed a prospective study of colonic polyps found during CLE and classified them according to the established criteria. A total of 115 patients with 115 colonic polyps were included. The real-time CLE diagnosis was compared with that from histology. The stored CLE images were evaluated later by a blinded observer. RESULTS The sensitivity, specificity, positive predictive value, and negative predictive value of real-time CLE in identifying colonic adenomas were 93.9 % (95 % confidence interval [CI] 85.4 - 97.6), 95.9 % (95 % CI 86.2 - 98.9), 96.9 % (95 % CI 89 - 99), and 92.2 % (95 % CI 81 - 97), respectively, compared with histological results. Interobserver agreement between real-time and post-CLE still-image evaluation was excellent (kappa = 0.929). Goblet cell depletion alone had a sensitivity of 84.9 % (95 % CI 73 - 92) and a specificity of 87.8 % (95 % CI 75 - 95), as well as excellent interobserver agreement (kappa = 0.824). CONCLUSIONS Endoscope integrated CLE with fluorescein staining may reliably assist in the real-time identification of colonic adenomas. Among three diagnostic categories, goblet cell depletion can be used to distinguish adenomas and hyperplastic polyps.

In vivo molecular imaging of epidermal growth factor receptor in patients with colorectal neoplasia using confocal laser endomicroscopy

Epidermal growth factor receptor (EGFR) plays an important role in tumorigenesis of colorectal cancer (CRC), and its in vivo molecular imaging in rodent models has become the subject of an increased number of studies using novel imaging techniques for gastrointestinal endoscopy. Current study aimed to evaluate the use of confocal endomicroscopy (CLE) for in vivo molecular imaging of EGFR in patients with colorectal neoplasia. Molecular imaging of colorectal neoplasia in patients was performed by CLE after topical application of a fluorescent-labeled molecular probe against EGFR. Representative images of CLE were chosen to calculate EGFR-specific fluorescence intensity. Targeted biopsy specimens were taken from each examined site during in vivo imaging for histology and immunohistochemistry (IHC). During in vivo molecular imaging in 37 patients, an EGFR-specific fluorescence signal was present in 18/19 CRC, and 12/18 colorectal adenomas. No or only weak fluorescence signal was observed in vivo in 10 cases of normal mucosa. CLE is a novel tool that could be used in molecular imaging with specific targeting of EGFR in patients with colorectal neoplasia. This technique demonstrates a promising imaging approach for targeted therapies of colorectal neoplasia.

Confocal laser endomicroscopy for in vivo diagnosis of gastric intraepithelial neoplasia: a feasibility study

BACKGROUND Confocal laser endomicroscopy (CLE) is a novel endoscopic modality that allows subsurface analysis of the gastric mucosa during ongoing endoscopy. Several studies have reported that this technique is of value in the diagnosis of premalignant lesions in the GI tract, but as yet no investigations have reported its application in the analysis of gastric intraepithelial neoplasia (GIN). OBJECTIVE To assess the feasibility of CLE for the identification and grading of GIN. DESIGN Prospective double-blind feasibility study. SETTING Qilu Hospital, Shandong University, Jinan, China. PATIENTS CLE images of 33 patients were first evaluated to establish the diagnostic criteria for gastric lesions. Eligible patients were then prospectively investigated by CLE using the newly established criteria. INTERVENTIONS All endoscopically suspicious lesions were examined by CLE, and CLE diagnoses were compared with corresponding histopathologic results. MAIN OUTCOME MEASUREMENTS Sensitivity, specificity, and positive and negative likelihood ratios of CLE diagnosis of biopsy-proven intraepithelial neoplasia by per-lesion analysis. RESULTS The sensitivity, specificity, and positive and negative likelihood ratios of CLE diagnosis of GIN were 77.8%, 81.8%, 4.28, and 0.27, respectively. The mean κ value for interobserver agreement for the diagnosis of GIN was 0.70 among endoscopists and 0.71 between endoscopist and GI pathologist. Intraepithelial neoplasia score ≥5 differentiated high-grade from low-grade intraepithelial neoplasia with a sensitivity of 66.7% and a specificity of 88.0%. LIMITATIONS Nonrandomized single-center study, limited number of patients. CONCLUSIONS CLE is an acceptable and potentially useful technology for the identification and grading of GIN in vivo. The diagnostic accuracy needs to be improved.

Confocal laser endomicroscopy for diagnosis of Helicobacter pylori infection: A prospective study

Background and Aim:  Confocal laser endomicroscopy (CLE) is a new endoscopy technique for subsurface analysis of the gastric mucosa and in vivo histology examination during endoscopy. We aimed to compare the clinical applicability and predictive power of CLE with the diagnosis of Helicobacter pylori infection in patients with gastrointestinal symptoms.

Confocal laser endomicroscopy for in vivo detection of gastric intestinal metaplasia: a randomized controlled trial.

BACKGROUND AND STUDY AIMS Gastric intestinal metaplasia (GIM) is associated with a risk for development of intestinal-type gastric cancer. This study aimed to compare the diagnostic yield of GIM from confocal laser endomicroscopy (CLE) and white light endoscopy (WLE). PATIENTS AND METHODS In a prospective, double-blind, randomized study, patients were randomly assigned to receive either CLE with targeted biopsies (group A) or WLE with a standard biopsy protocol (group B). RESULTS A total of 168 patients were finally analyzed (group A 85, group B 83). On a per-patient analysis, the diagnostic yields of GIM (including GIM with gastric intraepithelial neoplasia [GIN]) for groups A and B were 44.71 % and 31.33 %, respectively (P = 0.074). On a per-biopsy analysis, CLE-targeted biopsy gave a significantly higher diagnostic yield of GIM compared with WLE and standard biopsy, at 65.70 % (113 /172 biopsies) versus 15.73 % (81 /515 biopsies) (P < 0.001). Moreover, the diagnostic yield of the operative link on gastric intestinal metaplasia (OLGIM) assessment stages III and IV was higher at 20.93 % (36 /172 biopsies) in group A versus 4.08 % (21 /515 biopsies) in group B (P < 0.001). In addition, use of CLE-guided biopsy significantly decreased by 68 % (P < 0.001) the mean number of biopsies required per patient. CONCLUSIONS CLE with targeted biopsies is superior to WLE with standard biopsies for the detection and surveillance of GIM. The number of biopsies needed to confirm GIM is about one third of that needed with WLE with standard biopsies.

Mucosal barrier defects in gastric intestinal metaplasia: in vivo evaluation by confocal endomicroscopy

BACKGROUND Helicobacter pylori infection and intestinal metaplasia (IM) are associated with gastric cancer. An impaired gastric mucosal barrier could be involved in this carcinogenesis. OBJECTIVE To evaluate laser confocal laser endomicroscopy (CLE) for in vivo functional imaging of mucosal barrier defects in patients with IM. DESIGN Prospective, controlled study. SETTING A tertiary-care academic center. PATIENTS This study involved patients with IM of the gastric mucosa who underwent CLE for surveillance. INTERVENTIONS Specific IM mucosa and non-IM mucosa in patients were identified by CLE, and targeted biopsy samples were taken for histopathology and electron microscopy. MAIN OUTCOME MEASUREMENTS Post-CLE assessment of paracellular fluorescein leakage was devised and validated by electron microscopy. We also evaluated the effect of H pylori eradication on the mucosal barrier. RESULTS Forty-two patients were included. Of non-IM samples, the paracellular permeability was significantly increased in H pylori-positive samples compared with H pylori-negative controls (54 ± 31% vs 3 ± 6%, P < .05). Of IM samples, the permeability was significantly increased in both H pylori-negative and H pylori-positive samples (67 ± 34% and 72 ± 28% vs 3 ± 6%, both P < .05). The results of post-CLE assessment correlated well with the electron microscopy findings (R(2) 0.834, P < .0001). After the eradication of H pylori, the paracellular barrier dysfunction of non-IM mucosa was significantly improved as shown by electron microscopy and CLE (both P < .001). However, there was no significant change in IM mucosa. LIMITATIONS Single-center study. CONCLUSIONS CLE allows functional imaging of mucosal barrier defects. Gastric IM is associated with an impaired paracellular barrier irrespective of H pylori eradication.

Microalterations of Esophagus in Patients With Non-Erosive Reflux Disease: In-Vivo Diagnosis by Confocal Laser Endomicroscopy and Its Relationship With Gastroesophageal Reflux

OBJECTIVES:Objectively diagnosing non-erosive reflux disease (NERD) is still a challenge. We aimed to evaluate the use of in-vivo confocal laser endomicroscopy (CLE) to examine the microalterations of the esophagus in patients with NERD and its relationship with reflux episodes monitored by multiple intraluminal impedance-pH (MII-pH).METHODS:Patients with gastroesophageal reflux symptoms completed reflux disease questionnaires. NERD was determined by negative gastroscopy. Patients without reflux symptoms were recruited as controls. Pilot clinical study was followed by prospective controlled blinded study. All subjects were examined by white-light mode of the endoscopy followed by the standard CLE mode and then MII-pH monitoring. The microalterations seen on CLE images and the correlation between CLE features and reflux episodes were evaluated, the correlation between CLE and transmission electron microscope (TEM) data was also analyzed.RESULTS:On CLE images, NERD patients had more intrapapillary capillary loops (IPCLs) per image than did controls (8.29±3.52 vs. 5.69±2.31, P=0.010), as well as the diameter of IPCLs (19.48±3.13 vs. 15.87±2.21 μm, P=0.041) and intercellular spaces of squamous cells (3.40±0.82 vs. 1.90±0.53 μm, P=0.042). The receiver operating characteristic analysis indicated that IPCLs number (optimal cutoff >6 per image, area under the curve (AUC) 0.722, 95% confidence interval (CI) 0.592–0.853, sensitivity 67.7%, specificity 71.6%), IPCLs diameter (optimal cutoff >17.2 μm, AUC 0.847, 95% CI 0.747–0.947, sensitivity 81%, specificity 76%), and the intercellular spaces of squamous cells (optimal cutoff >2.40 μm, AUC 0.935, 95% CI 0.875–0.995, sensitivity 85.7%, specificity 90.5%) diagnosed NERD with reasonable accuracy. Combined features of dilatation of intercellular space plus increased IPCLs provided 100% specificity in the diagnosis of NERD patients. The intercellular spaces of squamous cells observed on CLE were highly related to that on TEM findings (r=0.75, P<0.001). Multivariate progressive regression analysis showed that acidic reflux, especially in the supine position, was related to the increased number and dilation of IPCLs in the squamous epithelium (β=0.063, t=2.895, P=0.038 and β=0.156, t=1.023, P=0.04).CONCLUSIONS:CLE represents a useful and potentially significant improvement over standard endoscopy to examine the microalterations of the esophagus in vivo. Acidic reflux is responsible for the microalterations in the esophagus of patients with NERD.

Magnified and enhanced computed virtual chromoendoscopy in gastric neoplasia: A feasibility study

AIM To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types I-III represent non-neoplastic lesions, and types IV-V represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line. RESULTS One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type I, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type II, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 10 lesions classified into type III, histopathology revealed 1 inflammation, 8 metaplasia and 1 LGD; for 9 lesions classified into type IV, histopathology revealed 4 inflammation, 1 atrophy and 4 HGD; for 7 lesions classified into type V, histopathology revealed 3 inflammation, 1 HGD and 3 cancers. A total of 172 still images, including 43 images by white light (MWL) and 129 images by M i-scan (43 with TE, 43 with SE and 43 with CE), were selected and sent to the endoscopist who did the analysis. General image quality of M i-scan with TE and SE was significantly better than that of MWL (TE, 4.55 ± 1.07; SE, 4.30 ± 1.02; MWL, 3.25 ± 0.99; P < 0.001). Visualization of pit pattern was significantly improved by M i-scan with SE (1.93 ± 0.25 vs 1.50 ± 0.50, P < 0.001). Microvessel visualization was significantly improved by M i-scan with TE (1.23 ± 0.78 vs 0.76 ± 0.73, P < 0.001). Demarcation line visualization was improved by M i-scan with both TE and SE (TE, 1.75 ± 0.52; SE, 1.56 ± 0.59; MWL, 0.98 ± 0.44; P < 0.001). M i-scan with CE did not show any significant improvements of image quality in general or in the 3 key parameters. Although M i-scan with TE and SE slightly increased the diagnostic yield of MWL, there was no significant difference (P > 0.1). CONCLUSION Although digital enhancement improves the image quality of magnification endoscopy, its value in improving the diagnostic yield seems to be limited.