A randomized trial comparing multiband mucosectomy and cap-assisted endoscopic resection for endoscopic piecemeal resection of early squamous neoplasia of the esophagus.

BACKGROUND AND AIM: Piecemeal endoscopic resection for esophageal high grade intraepithelial neoplasia (HGIN) or early squamous cell carcinoma (ESCC) is usually performed by cap-assisted endoscopic resection. This requires submucosal lifting and multiple snares. Multiband mucosectomy (MBM) uses a modified variceal band ligator without submucosal lifting. In high-risk areas where ESCC is common and endoscopic expertise is limited, MBM may be a better technique. We aimed to compare MBM to the cap-assisted technique for piecemeal endoscopic resection of esophageal ESCCs. METHODS: Patients with mucosal HGIN/ESCC (2 - 6 cm, maximum two-thirds of esophageal circumference) were included. Lesions, delineated by 1.25 % Lugol staining, were randomized to MBM or cap-assisted piecemeal resection. Endpoints were procedure time and costs, complete endoscopic resection, adverse events, and absence of HGIN/ESCC at 3-month and 12-month follow-up.  RESULTS: Endoscopic resection was performed in 84 patients (59 men, mean age 60) using MBM (n = 42) or the endoscopic resection cap (n = 42). There were no differences in baseline characteristics. Endoscopic complete resection was achieved in all lesions. Procedure time was significantly shorter with MBM (11 vs. 22 minutes, P < 0.0001). One perforation, seen after using the endoscopic resection cap, was treated conservatively. Total costs of disposables were lower for MBM (€200 vs. €251, P = 0.04). At 3-month and 12-month follow-ups none of the patients had HGIN/ESCC at the resection site. CONCLUSION: Piecemeal endoscopic resection of esophageal ESCC with MBM is faster and cheaper than with the endoscopic resection cap. Both techniques are highly effective and safe. MBM may have significant advantages over the endoscopic resection cap technique, especially in countries where ESCC is extremely common but limited endoscopic expertise and resources exist. (Netherlands trial register: NTR 3246.).

Fluorescence characteristics of human Barrett tissue specimens grafted on chick chorioallantoic membrane.

To improve (pre)malignant lesion identification in Barrett's esophagus (BE), recent research focuses on new developments in fluorescence imaging and spectroscopy to enhance tissue contrast. Our aim was to validate the chorioallantoic membrane (CAM) model as a preclinical tool to study the fluorescence characteristics such as autofluorescence and exogenously induced fluorescence of human Barrett's tissue. Therefore, esophageal biopsy specimens from Barrett's patients were freshly grafted onto the CAM of fertilized hen's eggs to simulate the in vivo situation. The BE biopsy specimens stayed between 1 and 9 days on the CAM to study the persistence of vitality. Fluorescence spectroscopy was performed using six excitation wavelengths (369, 395, 400, 405, 410, 416 nm). Obtained autofluorescence spectra were compared with in vivo spectra of an earlier study. Exogenous administration of 5-aminolevulinic-acid to the biopsy specimens was followed by fluorescence spectroscopy at several time points. Afterwards, the biopsy specimens were harvested and histologically evaluated. In total, 128 biopsy specimens obtained from 34 patients were grafted on the CAM. Biopsy specimens which stayed on average 1.7 days on the CAM were still vital. Autofluorescence spectra of the specimens correlated well with in vivo spectra. Administered 5-aminolevulinic-acid to the biopsy specimens showed conversion into protoporphyrin-IX. In conclusion, we showed that grafting freshly collected human BE biopsy specimens on the CAM is feasible. Our results suggest that the CAM model might be used to study the fluorescence behavior of human tissue specimens. Therefore, the CAM model might be a preclinical research tool for new photosensitizers.

Detection of buried Barrett's glands after radiofrequency ablation with volumetric laser endomicroscopy.

BACKGROUND AND AIMS: The prevalence and clinical relevance of buried Barrett's glands (BB) after radiofrequency ablation (RFA) in Barrett's esophagus (BE) are debated. Recent optical coherence tomography studies demonstrated a high prevalence of BBs. Direct histological correlation, however, has been lacking. Volumetric laser endomicroscopy (VLE) is a second-generation optical coherence tomography system capable of scanning a large surface of the esophageal wall layers with low-power microscopy resolution. The aim was to evaluate whether post-RFA subsquamous glandular structures (SGSs), detected with VLE, actually correspond to BBs by pursuing direct histological correlation with VLE images. METHODS: In vivo VLE was performed to detect SGSs in patients with endoscopic regression of BE post-RFA. A second in vivo VLE scan was performed to confirm correct delineation of the SGSs. After endoscopic resection, the specimens were imaged ex vivo with VLE. Extensive histological sectioning of SGS areas was performed, and all histology slides were evaluated by an expert BE pathologist. RESULTS: Seventeen patients underwent successful in vivo VLE (histological diagnosis before endoscopic treatment: early adenocarcinoma in 8 patients and high-grade dysplasia in 9). In 4 of 17 patients, no SGSs were identified during VLE, and a random resection was performed. In the remaining 13 patients (76%), VLE detected SGS areas, which were all confirmed on a second in vivo VLE scan and subsequently resected. Most SGSs identified by VLE corresponded to normal histological structures (eg, dilated glands and blood vessels). However, 1 area containing BBs was found on histology. No specific VLE features to distinguish between BBs and normal SGSs were identified. CONCLUSIONS: VLE is able to detect subsquamous esophageal structures. One area showed BBs beneath endoscopically normal-appearing neosquamous epithelium; however, most post-RFA SGSs identified by VLE correspond to normal histological structures. ( CLINICAL TRIAL REGISTRATION NUMBER: NTR4056.).

The combination of autofluorescence endoscopy and molecular biomarkers is a novel diagnostic tool for dysplasia in Barrett's oesophagus.

OBJECTIVE: Endoscopic surveillance for Barrett's oesophagus (BO) is limited by sampling error and the subjectivity of diagnosing dysplasia. We aimed to compare a biomarker panel on minimal biopsies directed by autofluorescence imaging (AFI) with the standard surveillance protocol to derive an objective tool for dysplasia assessment. DESIGN: We performed a cross-sectional prospective study in three tertiary referral centres. Patients with BO underwent high-resolution endoscopy followed by AFI-targeted biopsies. 157 patients completed the biopsy protocol. Aneuploidy/tetraploidy; 9p and 17p loss of heterozygosity; RUNX3, HPP1 and p16 methylation; p53 and cyclin A immunohistochemistry were assessed. Bootstrap resampling was used to select the best diagnostic biomarker panel for high-grade dysplasia (HGD) and early cancer (EC). This panel was validated in an independent cohort of 46 patients. RESULTS: Aneuploidy, p53 immunohistochemistry and cyclin A had the strongest association with dysplasia in the per-biopsy analysis and, as a panel, had an area under the receiver operating characteristic curve of 0.97 (95% CI 0.95 to 0.99) for diagnosing HGD/EC. The diagnostic accuracy for HGD/EC of the three-biomarker panel from AFI+ areas was superior to AFI- areas (p<0.001). Compared with the standard protocol, this panel had equal sensitivity for HGD/EC, with a 4.5-fold reduction in the number of biopsies. In an independent cohort of patients, the panel had a sensitivity and specificity for HGD/EC of 100% and 85%, respectively. CONCLUSIONS: A three-biomarker panel on a small number of AFI-targeted biopsies provides an accurate and objective diagnosis of dysplasia in BO. The clinical implications have to be studied further.

Fluorescence imaging for the detection of early neoplasia in Barrett's esophagus: old looks or new vision?

Early neoplasia arising from Barrett's esophagus is often small, focally distributed and endoscopically poorly visible, and random four-quandrant biopsies may easily miss early lesions. Advanced imaging techniques, such as (auto)fluorescence-based modalities, aim to increase the detection rate of early lesions or the yield of random biopsies. Fluorescence-based light-tissue interaction has been designed successfully in point-probe differentiating spectroscopy systems or integrated into wide-field endoscopic systems such as autofluorescence imaging (AFI). In this review, we discuss the most recent advances in fluorescence spectroscopy and imaging for detecting early Barrett's neoplasia. A spectroscopy probe, integrated into regular biopsy forceps, was shown to offer decent discriminatory capabilities, while ensuring spot-on correlation between the measured area and the corresponding histology. With this tool, surveillance endoscopy with random biopsies may become more efficient and sensitive. AFI was shown to increase the targeted detection of early neoplasia. However, random biopsies could compensate for this effect. The clinical impact of AFI on the diagnosis and the treatment of early neoplasia is limited, and yet AFI may offer a novel approach in biomarker-based risk-stratification models. Moreover, in combination with new, readily available contrast agents such as fluorescent lectins, fluorescence imaging may receive renewed interest.

The clinical consequences of advanced imaging techniques in Barrett's esophagus.

Evaluation of patients with Barrett's esophagus (BE) using dye-based chromoendoscopy, optical chromoendoscopy, autofluorescence imaging, or confocal laser endomicroscopy does not significantly increase the number of patients with a diagnosis of early neoplasia compared with high-definition white light endoscopy (HD-WLE) with random biopsy analysis. These newer imaging techniques are not more effective in standard surveillance of patients with BE because the prevalence of early neoplasia is low and HD-WLE with random biopsy analysis detects most cases of neoplasia. The evaluation and treatment of patients with BE and early-stage neoplasia should be centralized in tertiary referral centers, where procedures are performed under optimal conditions, by expert endoscopists. Lesions that require resection are almost always detected by HD-WLE, although advanced imaging techniques can detect additional flat lesions. However, these are of limited clinical significance because they are effectively eradicated by ablation therapy. No endoscopic imaging technique can reliably assess submucosal or lymphangio-invasion. Endoscopic resection of early-stage neoplasia in patients with BE is important for staging and management. Optical chromoendoscopy can also be used to evaluate lesions before endoscopic resection and in follow-up after successful ablation therapy.

Effects of autofluorescence imaging on detection and treatment of early neoplasia in patients with Barrett's esophagus.

BACKGROUND & AIMS: Studies have reported that autofluorescence imaging (AFI) increases targeted detection of high-grade intraepithelial neoplasia (HGIN) and intramucosal cancer (IMC) in patients with Barrett's esophagus (BE). We analyzed data from trials to assess the clinical relevance of AFI-detected lesions. METHODS: We collected information on 371 patients with BE, along with endoscopy and histology findings, from databases of 5 prospective studies of AFI (mean age, 65 years; 305 male). We compared these data with outcomes of treatment and follow-up. Study end points included the diagnostic value of AFI (proportion of surveillance patients with HGIN or IMC detected only by AFI-targeted biopsies) and value of AFI in selection of therapy (the proportion of patients for which detection of an HGIN or IMC lesion by AFI changed the treatment strategy based on white-light endoscopy or random biopsy analysis). RESULTS: Of study participants, 211 were referred for surveillance and 160 were referred for early stage neoplasia; HGIN or IMC were diagnosed in 147 patients. In 211 patients undergoing surveillance, 39 had HGIN or IMC (23 detected by white-light endoscopy, 11 detected by random biopsies, 5 detected by AFI). So, the diagnostic value of AFI was 5 (2%) of 211. In 24 patients, HGIN or IMC was diagnosed using only AFI. In 33 patients, AFI detected additional HGINs or IMCs next to lesions detected by primary white-light endoscopy. Lesions detected by AFI were treated in 57 patients: 26 patients underwent radiofrequency ablation and showed full remission of neoplasia, whereas 31 underwent endoscopic resection and 6 were found to have IMC. The value of AFI in selection of therapy was 6 (2%) of 371. CONCLUSIONS: Based on an analysis of data from clinical trials of patients with BE, detection of lesions by AFI has little effect on the diagnosis of early stage neoplasia or therapeutic decision making. AFI therefore has a limited role in routine surveillance or management of patients with BE.

Optimized endoscopic autofluorescence spectroscopy for the identification of premalignant lesions in Barrett's oesophagus.

OBJECTIVE: Fluorescence spectroscopy has the potential to detect early cellular changes in Barrett's oesophagus before these become visible. As the technique is based on varying concentrations of intrinsic fluorophores, each with its own optimal excitation wavelength, it is important to assess the optimal excitation wavelength(s) for identification of premalignant lesions in patients with Barrett's oesophagus. METHODS: The endoscopic spectroscopy system used contained five (ultra)violet light sources (λexc=369-416 nm) to generate autofluorescence during routine endoscopic surveillance. Autofluorescence spectroscopy was followed by a biopsy for histological assessment and spectra correlation. Three intensity ratios (r1, r2, r3) were calculated by dividing the area, A, under the spectral curve of selected emission wavelength ranges for each spectrum generated by each excitation wavelength λexc as follows (Equation is included in full-text article.). Double intensity ratios were calculated using two excitation wavelengths. RESULTS: Fifty-eight tissue areas from 22 patients were used for autofluorescence spectra analysis. Excitation with 395, 405 or 410 nm showed a significant (P≤0.0006) differentiation between intestinal metaplasia and grouped high-grade dysplasia/early carcinoma for intensity ratios r2 and r3. A sensitivity of 80.0% and specificity of 89.5% with an area under the ROC curve of 0.85 was achieved using 395 nm excitation and intensity ratio r3. CONCLUSION: Double excitation showed no additional value over single excitation. The combination of 395 nm excitation and intensity ratio r3 showed optimal conditions to discriminate nondysplastic from early neoplasia in Barrett's oesophagus.

Characterization of expression in mice of a transgene containing 3.3 kb of the human lactase-phlorizin hydrolase (LPH) 5' flanking sequence.

BACKGROUND AND AIM: The regulation of human intestinal lactase-phlorizin hydrolase remains incompletely understood. One kb of pig and 2 kb of rat 5'-flanking sequence controls correct tissue, cell, topographic, and villus LCT expression. To gain insight into human LCT expression, transgenic mouse lines were generated from 3.3 kb of human LPH 5' flanking sequence from a lactase persistent individual fused to a human growth hormone (hGH) reporter bounded by an insulator. METHODS: Four lines were identified in which reporter expression was specifically detectable in the intestine and no other organ, two of which demonstrated hGH expression specific to small and large intestine. Quantitative RT-PCR was carried out on proximal to distal segments of small intestine at fetal days 16.5 and 18.5 and at birth, postnatal days 7 and 28 in line 22. RESULTS: In fetal intestine, hGH expression demonstrated a proximal to distal gradient similar to that in native intestine. There was no significant difference between hGH expression levels at 7 and 28 days in segment 3, the midpoint of the small intestine, where expression of endogenous lactase is maximal at 7 days and declines significantly by 28 days. Distal small intestine displayed high levels of hGH expression in enteroendocrine cells, which were shown to be a subset of the PYY cells. CONCLUSIONS: Thus, a 3.3-kb LPH 5' flanking sequence construct from a lactase persistent individual is able to maintain postnatal expression in transgenic mice post weaning.