Role of confocal laser endomicroscopy in patients with early esophageal neoplasia

The Use of Confocal Laser Endomicroscopy in Diagnosing Barrett’s Esophagus and Esophageal Adenocarcinoma

Confocal laser endomicroscopy (CLE) is a diagnostic technique that enables real-time microscopic imaging during microscopic examination and evaluation of epithelial structures with 1000-fold magnification. CLE can be used in the diagnosis of various pathologies, in pneumology, and in urology, and it is very widely utilized in gastroenterology, most importantly in the diagnosis of Barrett’s esophagus (BE), esophageal adenocarcinoma (EAC), biliary strictures, and cystic pancreatic lesions. A literature search was made in MEDLINE/PubMed and Google Scholar databases while focusing on diagnostics using CLE of BE and EAC. We then examined randomized and observational studies, systematic reviews, and meta-analyses relating to the utilization of CLE in BE and EAC diagnostics. Here, we discuss whether CLE can be a suitable diagnostic method for surveillance of BE. Even though many studies have proven that CLE increases diagnostic accuracy in detecting neoplastic transformation of BE, CLE is still not used as a standard diagnostic tool in BE surveillance due to a deficiency of scientific evidence. More studies and data are needed if CLE is to find a place as a new technique in BE surveillance.

Confocal Laser Endomicroscopy Can Improve the Diagnosis Rate and Range Assessment of Patients With Conflicting Chronic Atrophic Gastritis Results of White Light Endoscopic and Pathological Diagnosis

Background and Aims

Chronic atrophic gastritis (CAG) is closely related to the development of gastric cancer. However, the diagnostic accuracy of white light endoscopy (WLE) biopsy for CAG is poor. The diagnostic role and efficacy of confocal laser endomicroscopy (CLE) in CAG missed under WLE biopsy remain unclear.

Methods

This study is a single-center prospective study that included 21 patients from 1,349 patients who underwent WLE and biopsy and whose WLE results confirmed CAG, but pathological results did not. Then, all these patients received CLE examination and underwent targeted biopsies and five-point standard biopsies. The sensitivity, specificity, and accuracy of CLE diagnosis and targeted biopsy were analyzed.

Results

The pathological results of five-point standard biopsies in 21 patients confirmed CAG, and 17 patients (81.0%) were confirmed to have intestinal metaplasia (IM). According to the image diagnosis of CLE, there were 19 cases (90.5%) of CAG and 14 cases (66.7%) of IM among these 21 patients. According to the targeted biopsy of CLE, 17 cases (81.0%) of CAG and 14 cases (66.7%) of IM were diagnosed. There was no significant difference between CLE image diagnosis and five-point standard biopsies in terms of atrophy severity score (p = 0.927), IM severity score (p = 0.250), atrophy scope score (p = 0.781), and IM scope score (p = 0.195). For CAG, the sensitivity and accuracy of CLE image diagnosis were higher than those of CLE targeted biopsies (90.5% vs. 81.0%, p = 0.331), but for IM, the diagnosis was the same.

Conclusions

CLE can improve the diagnosis rate of CAG and can increase the comprehensive assessment of the scope and severity of CAG.

Updated Kimura-Takemoto classification of atrophic gastritis

BACKGROUND

The Updated Sydney system for visual evaluation of gastric mucosal atrophy via endoscopic observation is subject to sampling error and interobserver variability. The Kimura-Takemoto classification system was developed to overcome these limitations.

AIM

To compare the morphological classification of atrophic gastritis between the Kimura-Takemoto system and the Updated Sydney system.

METHODS

A total of 169 patients with atrophic gastritis were selected according to diagnosis by the visual endoscopic Kimura-Takemoto method. Following the Updated Kimura-Takemoto classification system, one antrum biopsy and five gastric corpus biopsies were taken according to the visual stages of the Kimura-Takemoto system. The Updated Kimura-Takemoto classification system was then applied to each and showed 165 to have histological mucosal atrophy; the remaining 4 patients had no histological evidence of atrophy in any biopsy. The Updated Kimura-Takemoto classification was verified as a reference morphological method and applied for the diagnosis of atrophic gastritis. Adding one more biopsy from the antrum to the six biopsies according to the Updated Kimura-Takemoto classification, constitutes the updated combined Kimura-Takemoto classification and Sydney system.

RESULTS

The sensitivity for degree of mucosal atrophy assessed by the Updated Sydney system was 25% for mild, 36% for moderate, and 42% for severe, when compared with the Updated Kimura-Takemoto classification of atrophic gastritis for morphological diagnosis. Four types of multifocal atrophic gastritis were identified: sequential uniform (type 1; in 28%), sequential non-uniform (type 2; in 7%), diffuse uniform (type 3; in 23%), diffuse non-uniform (type 4; in 24%), and "alternating atrophic – non-atrophic" (type 5; in 18%). The pattern of the spread of atrophy, sequentially from the antrum to the cardiac segment of the stomach, which was described by the Updated Kimura-Takemoto system, was histologically confirmed in 82% of cases evaluated.

CONCLUSION

The Updated Sydney system is significantly inferior to the Updated Kimura-Takemoto classification for morphological verification of atrophic gastritis.

Probe-Based Confocal Laser Endomicroscopy and Barrett's Esophagus: Just a Scientific Toy or Significant Improvement in Diagnosis?

BACKGROUND

Barrett's esophagus (BE) requires surveillance to identify potential neoplasia at an early stage. The standard surveillance regimen includes random 4-quadrant biopsies by Seattle protocol. Main limitations of random biopsies are high risk of sampling error, difficulties in histology interpretation, common inadequate classification of pathohistological changes, increased risk of bleeding, and time necessary to acquire the final diagnosis. Probe-based confocal laser endomicroscopy (pCLE) has emerged as a potential tool with an aim to overcome these obvious limitations.

SUMMARY

pCLE represents a real-time microscopic imaging method that offers evaluation of epithelial and subepithelial structures with 1,000-fold magnification. In theory, pCLE has potential to eliminate the need for biopsy in BE patients. The main advantages would be real-time diagnosis and decision-making, greater diagnostic accuracy, and evaluation of larger area compared to random biopsies. Clinical pCLE studies in the esophagus show high diagnostic accuracy, and its high negative predictive value offers high reliability and confidence to exclude dysplastic and neoplastic lesions. However, it still cannot replace histopathology due to lower positive predictive value and sensitivity. Key Messages: Despite promising results, its role in routine use in patients with BE remains questionable primarily due to lack of well-organized double-blind randomized trials.

Optical biopsy of bladder cancer using confocal laser endomicroscopy

OBJECTIVE

Confocal laser endomicroscopy (CLE) is an emerging endoscopic technique that can provide in vivo histopathologic information. It may improve the diagnostic criteria for benign and neoplastic lesions of the bladder. In this study, we reported our experience with utilizing CLE imaging when treating bladder neoplasms, and investigated its diagnostic value with respect to histologic diagnosis.

MATERIALS AND METHODS

Twenty-one patients scheduled for diagnostic cystoscopy or transurethral resection of the bladder tumor were enrolled prospectively. CLE was performed after intravesical fluorescein administration and confocal video sequences were reviewed and analyzed retrospectively. Histopathology served as reference standard for comparison.

RESULTS

Confocal laser endomicroscopy-based classification combined with white light cystoscopy (WLC) images was consistent with histopathology in 17 cases (81.0%). Consensus with histopathological results was found in six cases (85.7%) for low-grade urothelial carcinoma and eight cases (80.0%) for high-grade urothelial carcinoma.

CONCLUSION

Confocal laser endomicroscopy was proved to be a useful technique that could complement white light cystoscopy by providing real-time histopathological information of bladder lesions.