Diagnostic accuracy of probe-based confocal laser endomicroscopy and narrow band imaging in detection of dysplasia in duodenal polyps

Clinical outcomes of endoscopic mucosal resection for large superficial nonampullary duodenal epithelial tumor: a single-center study

BACKGROUND AND AIM

Endoscopic mucosal resection (EMR) of superficial nonampullary duodenal epithelial tumors (SNADETs) is challenging, and to date, only a few studies assessed the clinical outcomes of EMR in the duodenum. The aim of this study was to evaluate the efficacy and safety of EMR for the treatment of SNADETs >10 mm.

PATIENTS AND METHODS

This is a single-center retrospective study reporting data from a cohort of consecutive patients undergoing EMR of large (>1 cm) SNADETs between January 2017 and December 2021.

RESULTS

A total of 81 patients with 83 lesions underwent EMR (70 conventional EMR, 13 underwater EMR). The median size was 20 mm (range: 10-60 mm). The mean procedure time was 45 ± 30 min, and the en-bloc resection rate was 47%. In all patients, SNADETs were successfully removed (i.e. technical success). Delayed bleeding occurred in 5 (6%) of EMRs. One delayed perforation occurred, which was managed surgically. Recurrence rate was 20% with a median follow-up period of 20.5 months. Recurrence was detected at the first endoscopic follow-up in 88% of cases, and all recurrences were successfully treated endoscopically. Lesion size ( P  = 0.04), previous endoscopic resection ( P  = 0.05), and piecemeal resection ( P  = 0.05) were independent risk factors of local recurrence after EMR on multivariate-adjusted analysis.

CONCLUSION

Large duodenal adenomas can be effectively managed by EMR. However, duodenal EMR of large lesions carries a significant risk of early recurrence, with a nonnegligible risk of adverse events. Lesion dimension, piecemeal resection, and previous endoscopic resection were associated with a higher recurrence rate. Close endoscopic follow-up is recommended given the high incidence of early recurrence, which can be successfully treated endoscopically.

Endoscopic diagnosis and treatment of superficial non-ampullary duodenal epithelial tumors: A review

The surface of the small bowel mucosa is covered more than any other section of the digestive canal; however, the overall prevalence of small bowel tumors of the whole gastrointestinal tract is evidently low. Owing to the improvement in endoscopic techniques, the prevalence of small bowel tumors has increased across multiple countries, which is mainly due to an increase in duodenal tumors. Superficial non-ampullary duodenal epithelial tumors (SNADETs) are defined as tumors originating from the non-ampullary region in the duodenum that share similarities and discrepancies with their gastric and colorectal counterparts in the pathogenesis and clinicopathologic characteristics. To date, white light endoscopy (WLE) remains the cornerstone of endoscopic diagnosis for SNADETs. Besides, narrow-band imaging (NBI) techniques and magnifying endoscopy (ME) have been widely used in the clinic and endorsed by multiple guidelines and consensuses for SNADETs' evaluation. Confocal laser endomicroscopy (CLE), endocytoscopy (ECS), and artificial intelligence (AI) are also up-and-coming methods, showing an exceptional value in the diagnosis of SNADETs. Similar to the endoscopic treatment for colorectal polyps, the choices for SNADETs mainly include cold snare polypectomy (CSP), endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and laparoscopic endoscopic cooperative surgery (LECS). However, owing to the narrow lumen, rich vascularity, weak muscle layer, abundant Brunner's gland, and the hardship of endoscope control, the duodenum ranks as one of the most dangerous operating areas in the digestive tract. Therefore, endoscopists must anticipate the difficulties in endoscopic maneuverability, remain aware of the increased risk of complications, and then select the appropriate treatment according to the advantages and disadvantages of each method.

Current status of endoscopic diagnosis and treatment for superficial non-ampullary duodenal epithelial tumors

Though superficial non-ampullary duodenal epithelial tumors (SNADETs) have been traditionally considered rare, there is a growing detection under the development and widespread of endoscopic techniques in recent times. Many case studies have revealed early manifestations of lesions through advanced endoscopic technology, however, because of the low incidence of duodenal tumors and challenges in diagnosing, the preoperative diagnosis criteria have not been established so far. In spite of this, recently the increasing detection rate of early duodenal epithelial lesions enhances the demand for minimally invasive treatment as well. The most suitable therapeutic endoscopic modality to remove duodenal lesions should be selected according to the size, location and histological invasive depth of duodenal lesions. Nevertheless, due to the special anatomical structure of the duodenum, the incidence of complications is much higher than in any other part of the digestive tract. To prevent these adverse events prophylactically, a few novel strategies have been applied effectively after resection. This review describes the current status of preoperative endoscopic diagnosis and endoscopic resection approaches, as well as countermeasures for avoiding procedure-related complications.

Endoscopic management of superficial nonampullary duodenal tumors: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends that all duodenal adenomas should be considered for endoscopic resection as progression to invasive carcinoma is highly likely.Strong recommendation, low quality evidence. 2: ESGE recommends performance of a colonoscopy, if that has not yet been done, in cases of duodenal adenoma.Strong recommendation, low quality evidence. 3: ESGE recommends the use of the cap-assisted method when the location of the minor and/or major papilla and their relationship to a duodenal adenoma is not clearly established during forward-viewing endoscopy.Strong recommendation, moderate quality evidence. 4: ESGE recommends the routine use of a side-viewing endoscope when a laterally spreading adenoma with extension to the minor and/or major papilla is suspected.Strong recommendation, low quality evidence. 5: ESGE suggests cold snare polypectomy for small (< 6 mm in size) nonmalignant duodenal adenomas.Weak recommendation, low quality evidence. 6: ESGE recommends endoscopic mucosal resection (EMR) as the first-line endoscopic resection technique for nonmalignant large nonampullary duodenal adenomas.Strong recommendation, moderate quality evidence. 7: ESGE recommends that endoscopic submucosal dissection (ESD) for duodenal adenomas is an effective resection technique only in expert hands.Strong recommendation, low quality evidence. 8: ESGE recommends using techniques that minimize adverse events such as immediate or delayed bleeding or perforation. These may include piecemeal resection, defect closure techniques, noncontact hemostasis, and other emerging techniques, and these should be considered on a case-by-case basis.Strong recommendation, low quality evidence. 9: ESGE recommends endoscopic surveillance 3 months after the index treatment. In cases of no recurrence, a further follow-up endoscopy should be done 1 year later. Thereafter, surveillance intervals should be adapted to the lesion site, en bloc resection status, and initial histological result. Strong recommendation, low quality evidence.

NBI utility in oncologic surgery: An organ by organ review

The main aims of the oncologic surgeon should be an early tumor diagnosis, complete surgical resection, and a careful post-treatment follow-up to ensure a prompt diagnosis of recurrence. Radiologic and endoscopic methods have been traditionally used for these purposes, but their accuracy might sometimes be suboptimal. Technological improvements could help the clinician during the diagnostic and therapeutic management of tumors. Narrow band imaging (NBI) belongs to optical image techniques, and uses light characteristics to enhance tissue vascularization. Because neoangiogenesis is a fundamental step during carcinogenesis, NBI could be useful in the diagnostic and therapeutic workup of tumors. Since its introduction in 2001, NBI use has rapidly spread in different oncologic specialties with clear advantages. There is an active interest in this topic as demonstrated by the thriving literature. It is unavoidable for clinicians to gain in-depth knowledge about the application of NBI to their specific field, losing the overall view on the topic. However, by looking at other fields of application, clinicians could find ideas to improve NBI use in their own specialty. The aim of this review is to summarize the existing literature on NBI use in oncology, with the aim of providing the state of the art: we present an overview on NBI fields of application, results, and possible future improvements in the different specialties.

The role of autofluorescence, photodynamic diagnosis and Photodynamic therapy in malignant tumors of the duodenum

This article presents the current state of knowledge and a review of the literature in terms of the prevalence, etiopathogenesis, differential diagnosis, management, prognosis, and treatment of malignant tumors of the duodenum. The role of autofluorescence and photodynamic diagnosis as an emerging treatment method for rarely o ccurring duodenal malignant neoplasms .. We selected publications which can be found in databases such as The National Center for Biotechnology Information, U.S. National Library of Medicine (PubMed), The American Chemical Society, The American Association of Pharmaceutical Sciences and The American Society for Photobiology and The Canada Institute for Scientific and Technical Information.

Shedding light on fibered confocal fluorescence microscopy: Applications in biomedical imaging and therapies

Discoveries of major importance in life sciences and preclinical research are linked to the invention of microscopes that enable imaging of cells and their microstructures. Imaging technologies involving in vivo procedures using fluorescent dyes that permit labelling of cells have been developed over the last two decades. Fibered confocal fluorescence microscopy (FCFM) is an imaging technology equipped with fiber-optic probes to deliver light to organs and tissues of live animals. This enables not only in vivo detection of fluorescent signals and visualization of cells, but also the study of dynamic processes, such cell proliferation, apoptosis and angiogenesis, under physiological and pathological conditions. This will allow the diagnosis of diseased organs and tissues and the evaluation of the efficacy of new therapies in animal models of human diseases. The aim of this report is to shed light on FCFM and its potential medical applications and discusses some factors that compromise the reliability and reproducibility of monitoring biological processes by FCFM. This report also highlights the issues concerning animal experimentation and welfare, and the contributions of FCFM to the 3Rs principals, replacement, reduction and refinement.

Diagnostic utility of probe-based confocal laser endomicroscopy in superficial non-ampullary duodenal epithelial tumors

Background and study aims  Endoscopic diagnosis of superficial non-ampullary duodenal epithelial tumors (SNADETs) has not been established. Probe-based confocal laser endomicroscopy (pCLE: Cellvizio) provides real-time endomicroscopic analysis. We developed and validated a new pCLE classification of SNADET based on abnormal findings. Patients and methods  pCLE scanning of 20 SNADET lesions including 16 adenomas and four carcinomas was retrospectively evaluated to explore abnormal pCLE findings in relation to histological features. Diagnostic yield of pCLE findings was prospectively evaluated in an additional 20 SNADET lesions including 16 adenomas and four carcinomas. Results  In a retrospective study, we identified four abnormal pCLE findings of SNADETs: (1) dark epithelium, (2) columnar cells irregularly extending to the lumen, (3) distorted crypt structure, and (4) fluorescein leakage. Dark epithelium distinguished neoplastic lesions (adenomas and carcinomas) from non-neoplastic duodenal mucosa with a sensitivity of 90 % and a specificity of 100 %. Distorted crypt structure distinguished carcinomas from adenomas and non-neoplastic duodenal mucosa with a sensitivity of 100% and a specificity of 94 %. In the prospective study, the sensitivity and the specificity of the dark epithelium for the diagnosis of neoplastic lesions (adenomas + carcinomas) was 75% and 100 %. Sensitivity and the specificity of the distorted crypt structure for discrimination of carcinoma from adenoma were 100 % and 94 %, respectively. Conclusions  The pCLE findings correlated with the histopathology of the SNADETs. Dark epithelium and distorted crypt structure were informative pCLE findings to predict presence of neoplasia and cancer in the SNADET, respectively. UMIN-CTR UMIN000013857 TRIAL REGISTRATION: Single-Center, prospective observational trial UMIN000013857 at upload.umin.ac.jp.

The Value of Confocal Laser Endoscopy in Assessing the Quality of Duodenal Ulcer Healing

BACKGROUND AND OBJECTIVE

Confocal laser endomicroscopy (CLE) is a novel endoscopic technique that can image cells and subcellular layers of the gastric mucosa in vivo. We aimed to investigate the value of CLE in assessing the quality of ulcer healing (QOUH) and preliminarily establish evaluation criteria.

MATERIALS AND METHODS

Patients with duodenal ulcers were enrolled. After duodenal ulcer healing, we compared the value of CLE and white light endoscopy (WLE) in assessing the QOUH by using the histopathological diagnosis as the gold standard. At the same time, immunohistochemistry was performed to examine the expressions of transforming growth factor β1 (TGF-β1) and fibroblast growth factor 2 (FGF-2) in normal and scar tissues.

RESULTS

In assessing the QOUH classified as poor, good, and excellent by the pathological classification, the sensitivity of WLE was 57.14%, 50%, and 47.06%, the specificity was 87.80%, 52.38%, and 81.58%, and the accuracy was 80.00%, 50.91%, and 70.91%, respectively. Meanwhile, the sensitivity of CLE was 73.33%, 85.19%, and 92.31%, the specificity was 95%, 85.71%, and 92.86%, and the accuracy was 89.09%, 85.45%, and 92.73%, respectively. The κ value for the correlation with pathological diagnosis grade was 0.38 for WLE vs. 0.74 for CLE. The assessment of the QOUH in the CLE image classification showed great improvement compared with that in the WLE image classification. The image classification of CLE was not associated with the immunohistochemical expression of TGF-β1 or FGF-2 according the Spearman rank correlation (P > 0.05).

CONCLUSION

Compared with WLE, CLE has a higher value in assessing the QOUH. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Magnified endoscopy with narrow-band imaging for the differential diagnosis of superficial non-ampullary duodenal epithelial tumors

BACKGROUND AND AIM

Differentiation of low-grade adenoma (Vienna category 3, C3) and high-grade adenoma/carcinoma (C4/5) among superficial non-ampullary duodenal epithelial tumors (SNADETs) using magnified endoscopy with narrow-band imaging (MNBI) is not established. The aim of this study is to clarify the diagnostic ability of MNBI to differentiate between C3 and C4/5 among SNADETs.

METHODS

A total of 585 MNBI images taken from 156 SNADETs were evaluated in a test and validation phase. In the test phase, MNBI patterns were extracted based on the combination of surface structure and vasculature. Comparison between MNBI patterns and histology was performed to establish diagnostic criteria to differentiate between C3 and C4/5. In the validation phase, the accuracy and interobserver agreement of the diagnostic criteria were assessed.

RESULTS

Four MNBI patterns (network, disappeared, white opaque substance and intrastructural vessels) with distinctive histological features were selected. The median number of MNBI patterns observed among C3 and C4/5 differed with significance (1 vs 2, p < .01). The pattern of disappeared was suggestive of C4/5. Diagnosis of C4/5 by using the criteria of 2 or more MNBI patterns or presence of disappeared pattern revealed a sensitivity of 76%, specificity of 63% and accuracy of 72%. Interobserver agreement of recognizing MNBI patterns was moderate (kappa 0.59).

CONCLUSION

Diagnosis based on MNBI patterns is useful to differentiate between C3 and C4/5 lesions among SNADETs.

Prospective Trial on Probe-Based Confocal Laser Endomicroscopy for the Identification of the Distal Limit in Rectal Adenocarcinoma

BACKGROUND

Intraoperative decision of the level of distal resection in rectal cancer is often imprecise, based exclusively on digital examination and pretherapeutic imaging.

DESIGN

Prospective, single institution, nonrandomized trial ( ClinicalTrial.gov identification no. NCT01887509) to evaluate the contribution of probe-based confocal laser endomicroscopy (pCLE) to establish the optimal resection margin of rectal adenocarcinoma. The primary outcome was the concordance in the identification of lower tumor margins between pCLE and histopathology. For each patient, pCLE examination was performed on nonneoplastic and neoplastic aspects of the distal tumor margin, before and after neoadjuvant chemoradiation, or preceding surgery, if chemoradiation was not required. Biopsies were taken at the same locations. The intraclass correlation coefficient was determined.

RESULTS

Twenty-one patients were enrolled. Thirteen patients completed the full study. Six patients completed imaging only before chemoradiation. Two patients retracted their consent after inclusion. A total of 134 videos and corresponding histopathology samplings were analyzed. The sensitivity and specificity of in vivo pCLE interpretation were 0.915 (95% confidence interval [CI] = 0.840-0.970) and 0.736 (95% CI = 0.657-0.821), respectively. The sensitivity and specificity of the blinded pCLE reinterpretation were 0.930 (95% CI = 0.858-0.980) and 0.688 (95% CI = 0.600-0.770), respectively. No deep layer tumor infiltration was encountered in the samplings with superficial healthy layers. The intraclass correlation coefficient for in vivo pCLE interpretation and blinded pCLE reinterpretation were 0.747 (95% CI = 0.257-0.993) and 0.766 (95% CI = 0.280-0.995), respectively.

CONCLUSIONS

This supports the concordance between pCLE and histopathology in identifying the "tumor-free" limit of a rectal tumor preceding resection.

Management of duodenal polyps

Duodenal adenomas are the most common type of polyp arising from the duodenum. These adenomas can occur within and outside of genetic syndromes, and are broadly classified as non-ampullary or ampullary depending on their location. All adenomas have malignant potential and are therefore appropriately treated by endoscopic resection. However, the unique anatomical properties of the duodenum, namely its relatively thin and vascular walls, narrow luminal diameter and relationship to the ampulla and its associated pancreatic and biliary drainage, pose an increased degree of complexity for any endoscopic interventions in this area. This review will discuss the epidemiology of duodenal adenomas, their endoscopic detection and diagnosis, and techniques for safe and effective endoscopic resection of ampullary and non-ampullary lesions.

Fluorescence lifetime measurement with confocal endomicroscopy for direct analysis of tissue biochemistry in vivo

Confocal endomicroscopy is a powerful tool for in vivo real-time imaging at cellular resolution inside a living body without tissue resection. Microscopic fluorescence lifetime measurement can provide information about localized biochemical conditions such as pH and the concentrations of oxygen and calcium. We hypothesized that combining these techniques could assist accurate cancer discrimination by providing both biochemical and morphological information. We designed a dual-mode experimental setup for confocal endomicroscopic imaging and fluorescence lifetime measurement and applied it to a mouse xenograft model of activated human pancreatic cancer generated by subcutaneous injection of AsPC-1 tumor cells. Using this method with pH-sensitive sodium fluorescein injection, we demonstrated discrimination between normal and cancerous tissues in a living mouse. With further development, this method may be useful for clinical cancer detection.

Development of a new classification for in vivo diagnosis of duodenal epithelial tumors with confocal laser endomicroscopy: A pilot study

BACKGROUND AND AIM

Confocal laser endomicroscopy (CLE) has been established for in vivo diagnosis of various gastrointestinal diseases. However, validated criteria for confocal diagnosis of duodenal tumors do not exist. Therefore, the aim of the present pilot study was to develop a novel classification for in vivo optical diagnosis of duodenal tumors using CLE.

METHODS

Consecutive patients with duodenal tumorous lesions were included. First, an initial classification system was developed which was then validated. Histopathology was used as a reference standard.

RESULTS

A simple classification system for in vivo diagnosis of duodenal epithelial tumors using CLE was developed. Sensitivity, specificity, and accuracy were 90%, 100%, and 97%, respectively. Positive and negative predictive values were calculated as 100% and 96%. The kappa coefficient representing consistency was 1 between observers and within each observer.

CONCLUSION

A new classification for in vivo diagnosis of duodenal epithelial tumors using confocal imaging has been developed. The new classification system allows adequate prediction of histology and could therefore be used to guide subsequent therapy of duodenal lesions.

Nonampullary duodenal adenoma: Current understanding of its diagnosis, pathogenesis, and clinical management

Nonampullary duodenal adenomas are relatively common in familial adenomatous polyposis (FAP), but nonampullary sporadic duodenal adenomas (SDAs) are rare. Emerging evidence shows that duodenal adenomas, regardless of their anatomic location and whether they are sporadic or FAP-related, share morphologic and molecular features with colorectal adenomas. The available data suggest that duodenal adenomas develop to duodenal adenocarcinomas via similar mechanisms. The optimal approach for management of duodenal adenomas remains to be determined. The techniques for endoscopic resection of duodenal adenoma include snare polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and argon plasma coagulation ablation. EMR may facilitate removal of large duodenal polyps. Although several studies have reported cases of successful ESD for duodenal adenomas, the procedure is technically difficult to perform safely because of the anatomical properties of the duodenum. Although current clinical practice recommends endoscopic resection of all large duodenal adenomas in patients with FAP, endoscopic treatment is usually insufficient to guarantee a polyp-free duodenum. Surgery is indicated for FAP patients with severe polyposis or nonampullary SDAs or FAP-related polyps not amenable to endoscopic resection. Further studies are needed to develop newer endoscopic techniques to guide diagnostic and therapeutic decisions for future management of nonampullary duodenal adenomas.

Progress of research and clinical application of probe-based confocal laser endomicroscopy

Probe based confocal laser endomicroscopy (pCLE) is a new endoscopic diagnostic method which integrates micro-imaging technology into endoscopy and can identify the morphological structure of particular tissue surface, so that the ongoing procedure of endoscopy can make the histopathological diagnosis. pCLE has the "optical biopsy" function, avoids shortcomings in physical biopsies such as being time-consuming, cumbersome, and prone to sampling error, and thus improves the diagnostic accuracy and efficiency. The field of research of pCLE as a new endoscopic imaging technology has been expanded from the digestive cavity structure to the respiratory system and urinary system. This article reviews the progress of research and clinical application of pCLE.

Emerging role of narrow band imaging in duodenum

Endoscopy using magnification narrow band imaging (mNBI) allows detailed assessment of mucosal surface and vascular pattern. This may help in better identification and prediction of the nature of the lesion. The role of this technology in duodenum is still evolving. Studies have shown that mNBI has high accuracy in predicting villous atrophy in the duodenum. Limited data suggests that this technique can provide additional information on duodenal polyps, nodules and ampullary tumour which can help guide their management. In this paper we describe the technique for duodenal assessment using NBI and review the existing literature evaluating its role in diagnosis of various duodenal pathologies.

Preoperative endoscopic diagnosis of superficial non-ampullary duodenal epithelial tumors, including magnifying endoscopy

Superficial non-ampullary duodenal epithelial tumor (SNADET) is defined as a sporadic tumor that is confined to the mucosa or submucosa that does not arise from Vater's papilla, and it includes adenoma and adenocarcinoma. Recent developments in endoscopic technology, such as high-resolution endoscopy and image-enhanced endoscopy, may increase the chances of detecting SNADET lesions. However, because SNADET is rare, little is known about its preoperative endoscopic diagnosis. The use of endoscopic resection for SNADET, which has no risk of metastasis, is increasing, but the incidence of complications, such as perforation, is significantly higher than in any other part of the digestive tract. A preoperative diagnosis is required to distinguish between lesions that should be followed up and those that require treatment. Retrospective studies have revealed certain endoscopic findings that suggest malignancy. In recent years, several new imaging modalities have been developed and explored for real-time diagnosis of these lesion types. Establishing an endoscopic diagnostic tool to differentiate between adenoma and adenocarcinoma in SNADET lesions is required to select the most appropriate treatment. This review describes the current state of knowledge about preoperative endoscopic diagnosis of SNADETs, such as duodenal adenoma and duodenal adenocarcinoma. Newer endoscopic techniques, including magnifying endoscopy, may help to guide these diagnostics, but their additional advantages remain unclear, and further studies are required to clarify these issues.

Diagnostic values of dual focus narrow band imaging and probe-based confocal laser endomicroscopy in FAP-related duodenal adenoma

BACKGROUND AND STUDY AIMS

Familial adenomatous polyposis (FAP) is associated with an increased risk of development of periampullary and nonampullary adenoma. Either routine biopsy or endoscopic removal of the lesion is generally required to identify the presence of adenoma. Because the risk of tissue sampling from the ampulla is high and nonampullary polyps are sometimes numerous, resection of all the lesions is time-consuming. This study aimed to evaluate the diagnostic values of duodenal adenoma by dual focus NBI (dNBI) and probe-based confocal endomicroscopy (pCLE) in FAP patients.

PATIENTS AND METHODS

The authors conducted a diagnostic study in a single tertiary-care referral center. Surveillance esophagogastroduodenoscopy with dNBI and pCLE was performed on 26 patients with FAP for real-time adenoma diagnosis by two different endoscopists; one used dNBI and the other pCLE. Histology from the matched lesion was used as the gold standard.

RESULTS

A total of 55 matched biopsies (25 ampullas, 30 nonampullas) were performed. The sensitivity, specificity, post predictive value (PPV), negative predictive value (NPV), and accuracy of dNBI vs. pCLE from all duodenal lesions were 96.9 % vs. 93.8 %, 78.3 % vs. 81 %, 86.1 % vs. 88.2 %, 94.7 vs. 89.5 %, and 92.4 % vs. 88.6 %, respectively.

CONCLUSIONS

For surveillance of periampullary and nonampullary adenoma in patients with FAP, the real-time readings provided a high degree of diagnostic value when histology was used as the gold standard. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT02162173).

In-vivo microscopy in the diagnosis of intestinal neoplasia and inflammatory conditions

Confocal laser endomicroscopy (CLE) is a rapidly emerging tool in endoscopic imaging allowing in-vivo microscopy of examined gastrointestinal mucosa. This review will discuss the most recent advances of confocal laser endomicroscopy in the diagnosis of intestinal neoplasia and inflammatory conditions.

Usefulness of white-light imaging-guided narrow-band imaging for the differential diagnosis of small ampullary lesions

BACKGROUND

Small ampullary tumors and inflammatory lesions have similar endoscopic findings and are difficult to differentiate. Narrow-band imaging (NBI) can visualize microvessels and mucosal microstructure clearly and is widely used to diagnose early gastric and colon cancer.

OBJECTIVE

To evaluate the usefulness of NBI for differentiating ampullary tumors from benign diseases.

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care hospital.

PATIENTS

All 45 patients who had suspicious ampullary lesions (enlarged or protruded morphology) during duodenoscopy and underwent NBI between March 2010 and January 2011.

INTERVENTIONS

NBI.

MAIN OUTCOME MEASUREMENTS

NBI images were assessed for irregular villous arrangement, irregular villous size, ridge disappearance, demarcation with normal villi, and abnormal microvasculature. Histology of NBI-guided lesion biopsy specimens provided the final diagnoses. Agreement between NBI images and histologic findings was analyzed.

RESULTS

Of the 60 ampullary lesions, 11, 26, and 23 were adenocarcinomas, adenomas, and benign inflammatory diseases, respectively. Irregular villous arrangement, irregular villous size, ridge disappearance, demarcation with normal villi, and abnormal microvasculature were observed in 45%, 63%, 50%, 48%, and 58% of the lesions, respectively. Multivariate analysis revealed that irregular villous arrangement (odds ratio [OR] 15.76; 95% confidence interval [CI], 3.38-64.12; P < .001) and abnormal microvasculature (OR 86.63; 95% CI, 14.56-515.41; P < .001) were significant independent factors for identifying ampullary adenomas and adenocarcinoma. All tumors had at least one abnormal NBI feature.

LIMITATIONS

Retrospective design.

CONCLUSION

The NBI findings of irregular villous arrangement and/or abnormal microvasculature were useful for differentially diagnosing ampullary tumors. NBI may complement the accurate diagnosis of ampullary lesions by white-light imaging.

Probe-based confocal laser endomicroscopy (pCLE) - a new imaging technique for in situ localization of spermatozoa

In azoospermic patients, spermatozoa are routinely obtained by testicular sperm extraction (TESE). However, success rates of this technique are moderate, because the site of excision of testicular tissue is determined arbitrarily. Therefore the aim of this study was to establish probe-based laser endomicroscopy (pCLE) a noval biomedical imaging technique, which provides the opportunity of non-invasive, real-time visualisation of tissue at histological resolution. Using pCLE we clearly visualized longitudinal and horizontal views of the tubuli seminiferi contorti and localized vital spermatozoa. Obtained images and real-time videos were subsequently compared with confocal laser scanning microscopy (CLSM) of spermatozoa and tissues, respectively. Comparative visualization of single native Confocal laser scanning microscopy (CLSM, left) and probe-based laser endomicroscopy (pCLE, right) using Pro Flex(TM) UltraMini O after staining with acriflavine.

Detection of a fluorescent-labeled avidin-nucleic acid nanoassembly by confocal laser endomicroscopy in the microvasculature of chronically inflamed intestinal mucosa

Inflammatory bowel diseases are chronic gastrointestinal pathologies causing great discomfort in both children and adults. The pathogenesis of inflammatory bowel diseases is not yet fully understood and their diagnosis and treatment are often challenging. Nanoparticle-based strategies have been tested in local drug delivery to the inflamed colon. Here, we have investigated the use of the novel avidin-nucleic acid nanoassembly (ANANAS) platform as a potential diagnostic carrier in an experimental model of inflammatory bowel diseases. Fluorescent- labeled ANANAS nanoparticles were administered to mice with chemically induced chronic inflammation of the large intestine. Localization of mucosal nanoparticles was assessed in vivo by dual-band confocal laser endomicroscopy. This technique enables characterization of the mucosal microvasculature and crypt architecture at subcellular resolution. Intravascular nanoparticle distribution was observed in the inflamed mucosa but not in healthy controls, demonstrating the utility of the combination of ANANAS and confocal laser endomicroscopy for highlighting intestinal inflammatory conditions. The specific localization of ANANAS in inflamed tissues supports the potential of this platform as a targeted carrier for bioactive moieties in the treatment of inflammatory bowel disease.

Confocal endomicroscopy shows food-associated changes in the intestinal mucosa of patients with irritable bowel syndrome

BACKGROUND & AIMS

We investigated suspected food intolerances in patients with irritable bowel syndrome (IBS) using confocal laser endomicroscopy (CLE) for real-time visualization of structural/functional changes in the intestinal mucosa after food challenge. Patients with functional changes after food challenge (CLE+) were placed on personalized exclusion diets and followed up for long-term symptom relief.

METHODS

Thirty-six IBS patients with suspected food intolerance and 10 patients with Barrett's esophagus (controls) without IBS symptoms were examined by CLE at University Hospital Schleswig-Holstein (Kiel, Germany). Diluted food antigens were administered directly to the duodenal mucosa through the working channel of the endoscope. Epithelial breaks, intervillous spaces, and the number of intraepithelial lymphocytes (IEL) were measured before and after the food challenge. CLE+ patients were placed on exclusion diets, given symptom score questionnaires, and followed up for 1 year; controls resumed their previous diet.

RESULTS

CLE showed a real-time response to food antigens in 22 of 36 patients; no responses were observed in 14 of 36 patients (CLE-) or any of the controls. Baseline IELs were significantly higher in CLE+ than CLE- subjects (P = .004); numbers increased significantly after food challenge (P = .0008). Within 5 minutes of exposure of CLE+ patients to food antigens, IELs increased, epithelial leaks/gaps formed, and intervillous spaces widened. Epithelial leaks and intervillous spaces also increased significantly in CLE+ vs baseline (both P < .001). The concordance of IELs measured by CLE and conventional histology was 70.6%; they did not correlate (P = .89; r(2) = 0.027). Symptom scores improved more than 50% in CLE+ patients after a 4-week exclusion diet and increased to 74% at 12 months; symptoms continued in CLE- patients.

CONCLUSIONS

Based on CLE analysis of IBS patients with a suspected food intolerance, exposure to candidate food antigens caused immediate breaks, increased intervillous spaces, and increased IELs in the intestinal mucosa. These changes are associated with patient responses to exclusion diets. Registered at clinicaltrials.gov (registration number: NCT01692613).

Endoscopic molecular imaging of cancer

White light endoscopy has proven to be a very powerful tool in oncology. There is still, however, a need for better endoscopic techniques to overcome the current limitations of white light optics. New technologies that allow higher sensitivity, improved microanatomy and molecular characterization have been available for in vitro microscopy and are now being translated into in vivo endoscopy. Endoscopic molecular imaging is still in its infancy but holds the promise for enhancing sensitivity for early lesions, thus allowing earlier diagnosis and enabling early image-guided endoscopic intervention. A key feature of endoscopic molecular imaging is its increased sensitivity and specificity, which will be illustrated in this article, as well as describing perspectives on its future use in oncologic surgery.

Advances in diagnostic endoscopy for duodenal, including ampullary, adenoma

Currently, the strategy for real-time endoscopic diagnosis of duodenal, including ampullary, adenoma is still unclear. In the era of high-definition and magnification endoscopy, using this modality for the detection and diagnosis of these neoplasms is very challenging for endoscopists. Over the past 10 years, many instruments have been developed to improve the detection rate of duodenal and ampullary polyps and to distinguish between adenoma and non-adenoma. The present review will focus on these novel methods and their usefulness in the diagnosis of ampullary and non-ampullary adenoma.

Advanced endoscopic imaging for dysplasia surveillance in ulcerative colitis

Ulcerative colitis is a well-characterized chronic inflammatory bowel disease with a significantly increased risk for developing colorectal neoplasia. A rigorous colonoscopy surveillance program has been shown to undoubtedly reduce this risk. White light endoscopy with random 4-quadrant biopsies in addition to target biopsies of suspicious lesions has been considered the standard of care. However, interval cancers between successive surveillance colonoscopies have been identified. Recently, multiple new endoscopic imaging technologies such as standard chromoendoscopy with methylene blue, virtual chromoendoscopy, autofluorescence imaging, confocal laser endomicroscopy and endocytoscopy were developed to provide a more detailed visualization of the mucosa by enhancing morphology and vascularization. This review will provide a comprehensive approach to advanced endoscopic imaging useful for dysplasia surveillance in longstanding ulcerative colitis patients.