Applications and Advancements in the Use of High-resolution Microendoscopy for Detection of Gastrointestinal Neoplasia

Abstract

The high-resolution microendoscope (HRME) is a novel imaging modality that allows real-time epithelial imaging at subcellular resolution. Used in concert with any standard endoscope, this portable, low cost, ‘optical biopsy’ technology has the ability to provide images of cellular morphology during a procedure. This technology has been the subject of a number of studies investigating its use in screening and surveillance of a range of gastrointestinal neoplasia, including esophageal adenocarcinoma(EAC), esophageal squamous cell cancer(ESCC), colorectal neoplasia(CRC) and anal neoplasia. These studies have shown that HRME is a modality that consistently provides high specificity, negative predictive value, and accuracy across different diseases. In addition, they have illustrated that HRME users can be relatively easily trained in a short period of time and that users have demonstrated solid inter-rater reliability. These features make HRME a potential complement to high definition white light imaging, narrow band imaging and other ‘red flag technologies’ in facilitating real-time clinical diagnosis, endoscopic therapy and margin determination. Further clinical validation is needed to determine whether this translates to reduced procedure times, pathology costs, and follow up procedures. Finally, the HRME has a relatively simple design compared to other similar technologies, making it portable, simple to maintain, and low cost. This may allow the HRME device to function in both advanced care settings as well as in places with less resources and specialized support systems. As a whole, the HRME device has shown good performance along with low-cost and portable construction, and its application in different conditions and settings has been promising.

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“…High-resolution microendoscopy (HRME) allows the user to conduct high-quality, real-time imaging at the cellular level in vivo [27] , [28] . HRME is therefore becoming an adjunct to established screening modalities to enhance the detection of precancerous and cancerous lesions at multiple sites, including the esophagus, colon, and cervix, as well as the oral cavity and gastrointestinal tract [29] – [32] . Particularly relevant for low-resource settings where access to traditional pathology services is limited, HRME can become a valuable tool to enhance screen-and-treat programs, especially as the development of smartphone-based image analysis programs bolsters the diagnostic capacity of the imaging modality [25] , [33] .…”

Advanced Imaging in Barrett's Esophagus

“…The probe is small and portable and can be reused about 60 to 75 times, and current prototypes have been built for less than $3500. 61 An initial study showed the feasibility of HRME to assess ex vivo endoscopic mucosal resection (EMR) specimens in patients with a prior diagnosis of BE with HGD or adenocarcinoma. 62 One study compared 20 gastroenterologists with no prior microendoscopic experience to 3 endoscopists who had performed greater than 50 HRME cases in assessing HRME images.…”

Comparative Study Regarding the Properties of Methylene Blue and Proflavine and Their Optimal Concentrations for In Vitro and In Vivo Applications

“…PRO is also known to have a mutagenic effect on DNA by intercalating between nucleic acid base pairs; this makes PRO a special type of mutagenic compound because it causes base pair-deletions or base pair-insertions rather than substitutions. In the presence of light, PRO can also induce double-stranded breaks in DNA [7,8].…”