Cheng-Jun Zhou

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.

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 endomicroscopy for in vivo prediction of completeness after endoscopic mucosal resection

BackgroundEndoscopic mucosal resection (EMR) is an alternative to surgery for removal of superficial gastric neoplastic lesions. Residual neoplastic tissue of the resection interface is difficult to detect by conventional endoscopy. The aim of this study is to assess the efficacy of confocal laser endomicroscopy (CLE) in predicting complete resection margins after EMR.MethodsEMR was performed by using cap-assisted or “inject and cut” resection technique. Two weeks after EMR, the circumferential margins of the defect were inspected by using CLE, and completeness of excision was predicted from the CLE image. Additional EMR was performed if necessary. In vivo CLE diagnosis was validated against final histopathology.ResultsTwenty-seven lesions were removed by EMR in 27 patients. After excluding 3 patients for gastrectomy, a total of 24 patients underwent CLE assessment, of whom 9 with indefinite lateral margins underwent at least two consecutive CLE follow-ups. A total of 19 lesions were regarded as complete remission, and 5 lesions (21.7%) were incompletely excised according to final pathologic diagnosis. Accuracy of CLE in predicting incomplete resection for original lesions was 91.7%, with sensitivity and specificity of 100.0 and 89.5%, respectively. The residual lesions were treated by additional EMR guided by CLE. There was no recurrence on endoscopic biopsies at mean (range) follow-up of 8.3 (4–15) months.ConclusionsConfocal laser endomicroscopy has high accuracy for prediction of remnant tissue after EMR, and may lead to significant improvements in clinical surveillance after endoscopic resection.

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.

In vivo molecular imaging of gastric cancer by targeting MG7 antigen with confocal laser endomicroscopy.

BACKGROUND AND STUDY AIMS In vivo molecular imaging represents a powerful tool for the immediate diagnosis of gastric cancer. In this study, the monoclonal antibody MG7, which is a specific molecular marker against gastric cancer, was labeled with fluorescent agents to enable in vivo real-time imaging by confocal laser endomicroscopy (CLE). PATIENTS AND METHODS In vivo molecular imaging was performed in tumor-bearing mice from two kinds of human gastric cancer cell lines. Xenograft tumors were visualized in vivo first with a whole-body fluorescent imaging device and then by CLE using fluorescently labeled MG7 antibody. Gastric cancerous tissue and noncancerous mucosa from human biopsies or surgical specimens were also examined ex vivo by CLE. RESULTS Intravital imaging of xenograft tumors revealed a specific cellular signal, whereas no specific signal was observed in control tissue or in mice injected with irrelevant antibodies. An ex vivo experiment on human specimens using a rigid confocal probe showed positive fluorescent staining in 22/23 samples diagnosed as gastric cancer and weak signals in 5/23 noncancerous tissue samples. CLE evaluation correlated well with immunohistochemical findings. CONCLUSIONS Screening tumors in vivo by CLE may help to detect MG7-Ag-positive tissues, decrease the sampling error by screening the large tumor surface not routinely screened by biopsy or conventional immunohistochemistry, and facilitate early detection of gastric carcinoma.

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.

Learning Curve and Interobserver Agreement of Confocal Laser Endomicroscopy for Detecting Precancerous or Early-Stage Esophageal Squamous Cancer

Background Confocal laser endomicroscopy (CLE) can provide in vivo subcellular resolution images of esophageal lesions. However, the learning curve in interpreting CLE images of precancerous or early-stage esophageal squamous cancer is unknown. The goal of this study is to evaluate the diagnostic accuracy and inter-observer agreement for differentiating esophageal lesions in CLE images among experienced and inexperienced observers and to assess the learning curve. Method After a short training, 8 experienced and 14 inexperienced endoscopists evaluated in sequence 4 sets of high-quality CLE images. Their diagnoses were corrected and discussed after each set. For each image, the diagnostic results, confidence in diagnosis, quality and time to evaluate were recorded. Results Overall, diagnostic accuracy was greater for the second, third, fourth set of images as compared with the initial set (odds ratio [OR] 2.01, 95% CI 1.22–3.31; 7.95, 3.74–16.87; and 6.45, 3.14–13.27), respectively, with no difference between the third and fourth sets in accuracy (p = 0.67). Previous experience affected the diagnostic accuracy only in the first set of images (OR 3.70, 1.87–7.29, p<0.001). Inter-observer agreement was higher for experienced than inexperienced endoscopists (0.732 vs. 0.666, p<0.01) Conclusion CLE is a promising technology that can be quickly learned after a short training period; previous experience is associated with diagnostic accuracy only at the initial stage of learning.