Use of narrow band imaging in assessing duodenal villous atrophy

Narrow-band imaging for optical diagnosis of duodenal villous atrophy in patients with suspected coeliac disease: A systematic review and meta-analysis

BACKGROUND

Narrow-band imaging (NBI) is a readily accessible imaging technique that enhances mucosal visualisation, allowing for a more accurate assessment of duodenal villi. However, its role in the diagnosis of coeliac disease (CD) in clinical practice remains limited.

METHODS

We systematically searched several databases in June 2023 for studies evaluating the diagnostic accuracy of NBI for detecting duodenal villous atrophy (VA) in patients with suspected CD. We calculated the summary sensitivity, specificity, and likelihood ratios using a bivariate random-effects model. The study followed PRISMA guidelines and was registered at PROSPERO (CRD42023428266).

RESULTS

A total of 6 studies with 540 participants were included in the meta-analysis. The summary sensitivity of NBI to detect VA was 93% (95% CI, 81% - 98%), and the summary specificity was 95% (95% CI, 92% - 98%). The area under the summary receiver operating characteristic curve was 0.98 (95% CI, 96 - 99). The positive and negative predictive values of NBI were 94% (95% CI, 92% - 97%) and 92% (95% CI, 90% - 94%), respectively.

CONCLUSION

NBI is an accurate non-invasive tool for identifying and excluding duodenal VA in patients with suspected CD. Further studies using a validated classification are needed to determine the optimal role of NBI in the diagnostic algorithm for CD.

Near-focus narrow-band imaging classification of villous atrophy in suspected celiac disease: development and international validation

BACKGROUND AND AIMS

There are no agreed-on endoscopic signs for the diagnosis of villous atrophy (VA) in celiac disease (CD), necessitating biopsy sampling for diagnosis. Here we evaluated the role of near-focus narrow-band imaging (NF-NBI) for the assessment of villous architecture in suspected CD with the development and further validation of a novel NF-NBI classification.

METHODS

Patients with a clinical indication for duodenal biopsy sampling were prospectively recruited. Six paired NF white-light endoscopy (NF-WLE) and NF-NBI images with matched duodenal biopsy sampling including the bulb were obtained from each patient. Histopathology grading used the Marsh-Oberhuber classification. A modified Delphi process was performed on 498 images and video recordings by 3 endoscopists to define NF-NBI classifiers, resulting in a 3-descriptor classification: villous shape, vascularity, and crypt phenotype. Thirteen blinded endoscopists (5 expert, 8 nonexpert) then undertook a short training module on the proposed classification and evaluated paired NF-WLE-NF-NBI images.

RESULTS

One hundred consecutive patients were enrolled (97 completed the study; 66 women; mean age, 51.2 ± 17.3 years). Thirteen endoscopists evaluated 50 paired NF-WLE and NF-NBI images each (24 biopsy-proven VAs). Interobserver agreement among all validators for the diagnosis of villous morphology using the NF-NBI classification was substantial (κ = .71) and moderate (κ = .46) with NF-WLE. Substantial agreement was observed between all 3 NF-NBI classification descriptors and histology (weighted κ = 0.72-.75) compared with NF-WLE to histology (κ = .34). A higher degree of confidence using NF-NBI was observed when assessing the duodenal bulb.

CONCLUSIONS

We developed and validated a novel NF-NBI classification to reliably diagnose VA in suspected CD. There was utility for expert and nonexpert endoscopists alike, using readily available equipment and requiring minimal training. (Clinical trial registration number: NCT04349904.).

Utility of narrow band imaging in predicting histology in celiac disease

BACKGROUND

Narrow band imaging (NBI) with magnification better visualizes the duodenal microsurface and mucosal vascularity. NBI delineates villous atrophy better than conventional white light endoscopy.

AIMS

This study was conducted to evaluate the diagnostic accuracy of narrow band imaging with magnification (NBI-ME) in celiac disease (CD).

METHODS

In this prospective study, consecutive patients of suspected CD and controls were subjected to tissue transglutaminase antibody test and endoscopic evaluation initially with white light followed by NBI-ME, and biopsies were taken from duodenum. Duodenal villous patterns on NBI were interpreted as normal, blunted distorted, and absent. Severity of villous atrophy was reported according to the modified Marsh criteria.

RESULTS

One hundred and twenty-two patients (mean age of 27.53 ± 13.37 years and a male to female ratio of 1:1.26) and 40 controls were studied. The sensitivity and specificity of NBI-ME in predicting villous atrophy were found to be 95.54% and 90%, respectively. The specificity and negative predictive value of NBI-ME in predicting villous atrophy amongst controls was 100% and 97.5%, respectively. Abnormal findings (blunted and absent villous patterns) combined with elevated transglutaminase antibody (> 5-fold) were found to have high accuracy in predicting villous atrophy.

CONCLUSION

NBI with magnification has high sensitivity and specificity in predicting villous atrophy in patients with celiac disease.

Narrow-band imaging with magnification and the water immersion technique: a case-finding, cost-effective approach to diagnose villous atrophy

INTRODUCTION

Narrow-band imaging with magnification endoscopy (NBI-ME) allows real-time visual assessment of the mucosal surface and vasculature of the gastrointestinal tract. This study aimed to determine the performance of NBI-ME combined with the water immersion technique (NBI-ME-WIT) in detecting villous atrophy.

METHODS

All patients who underwent gastroscopy were included. The duodenum was further examined with NBI-ME-WIT only after examination with white light endoscopy did not reveal a cause of anaemia or dyspepsia. Targeted biopsies were taken of visualised areas. NBI-ME-WIT findings were compared with the final histopathological analysis. We calculated the sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of NBI-ME-WIT in detecting villous atrophy and the hypothetical cost saved by using a biopsy-avoiding approach.

RESULTS

124 patients (83 female) with a mean age of 46 (range 18-82) years were included. The most common indication for gastroscopy was abdominal pain (39%), followed by anaemia (35%), chronic diarrhoea/altered bowel habits (19%) and dyspepsia (6%). NBI-ME-WIT was able to detect all nine patients with villous atrophy - eight patchy and one total villous atrophy. The Sn, Sp, PPV and NPV of NBI-ME-WIT in detecting villous atrophy were 100.0%, 99.1%, 90.0% and 100.0%, respectively. Taking into account the cost of biopsy forceps (AUD 17) and pathology (AUD 140), this biopsy-avoidance strategy could have saved AUD 18,055 in these patients.

CONCLUSION

NBI-ME-WIT is a specific and sensitive tool to recognise and accurately diagnose villous atrophy. Biopsies can be avoided in patients with normal-sized villi, which may decrease the overall cost of the procedure.

A comparison study between Magniview and high definition white light endoscopy in detecting villous atrophy and coeliac disease: A single centre pilot study

BACKGROUND AND AIMS

Coeliac disease may be missed at gastroscopy. We aimed to assess the sensitivity of Pentax optical zoom technology endoscopes in detecting duodenal villous atrophy and the ease of image interpretation by non-coeliac specialists.

METHOD

All patients attending for a gastroscopy were assessed for endoscopic villous atrophy in part one and two of the duodenum with high definition white light endoscopy and magnification endoscopy. Endoscopic findings of the duodenum were compared to histology as the reference standard. A short training video of varying degrees of villous atrophy seen by magnification endoscopy was used to train individuals. They were then assessed for the ability to differentiate between normal duodenum and villous atrophy.

RESULTS

Two hundred and fifty patients were prospectively recruited (145 females, 58%; age range 16-84, median age 50.5). Ninety-six patients had villous atrophy on histology (38.4%) 154 were controls. Magnification endoscopy had a higher sensitivity in detecting villous atrophy compared to high definition white light endoscopy (86.4% versus 78.4%, p = .0005). 9/10 individuals undertaking magnification endoscopy training correctly identified all cases of villous atrophy.

CONCLUSION

Magnification endoscopy has superior diagnostic sensitivity in detecting villous atrophy compared to high definition white light endoscopy and the potential to be easily adopted by all endoscopists.

Optimizing the diagnosis of celiac disease

PURPOSE OF REVIEW

The diagnostic approach in celiac disease is continuously evolving as our understanding of its pathophysiology improves. This review aims to provide a summary of contemporary work that supports optimization of the diagnosis of this common yet underdiagnosed condition.

RECENT FINDINGS

The recently updated National Institute of Clinical Excellence and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines and the contentious biopsy-free diagnostic approach will be discussed. We will review the evidence advocating optimal biopsy techniques such as single bite biopsy and controversial bulb biopsy sampling to increase diagnostic yield. Recent data providing phenotypical characterization and clinical outcomes of celiac subtypes such as potential celiac disease, seronegative celiac disease and ultrashort celiac disease will be covered. We will present emerging evidence on novel case finding strategies with point of care tests. Promising novel markers for celiac disease such as serum intestinal fatty acid binding protein and in-vitro gluten challenge will be included.

SUMMARY

Recent work has demonstrated the clinical significance of the celiac disease subtypes, emphasizing the importance of careful diagnosis and recognition. There is a move toward a less invasive and perhaps more cost-effective diagnostic approach in celiac disease, but duodenal biopsy remains the gold standard at present for all adults and the majority of pediatric patients.

High definition i-SCAN endoscopy with water immersion technique accurately reflects histological severity of celiac disease

BACKGROUND AND AIMS

Severe villous atrophy can be revealed with conventional white light endoscopy (WLE), however, milder grades or patchy villous atrophy are more difficult to detect. Novel endoscopic techniques such as high definition i-SCAN endoscopy with the water immersion technique (i-SCAN-HDWI) may provide the ability to visualize duodenal villi more accurately. We aimed to determine the performance of i-SCAN-HDWI in evaluating the severity of histological damage in the duodenum of patients with celiac disease.

PATIENTS AND METHODS

A retrospective cohort study was performed in a single tertiary academic endoscopic center. We studied 58 patients (46 women; median age 36.5 years, range 18 - 72 years) with positive anti-TTG IgA antibody. The villous pattern of the second part of the duodenum was assessed by WLE and i-SCAN-HDWI. The endoscopic grades in both techniques were correlated using Marsh histologic grades by Spearman correlation coefficient. The diagnostic accuracy of i-SCAN-HDWI for detection of patchy or complete atrophy of the villi was evaluated.

RESULTS

A significant correlation was demonstrated between endoscopic grade using i-SCAN-HDWI and Marsh histologic grade (r = 0.732; P < 0.00001). The correlation between WLE grade and Marsh histologic grade was inferior to i-SCAN-HDWI (r = 0.31; P = 0.01). The sensitivity of i-SCAN-HDWI was 96 % (95 %CI: 85 - 99 %) and the specificity was 63 % (95 %CI: 26 - 90 %) in diagnosing abnormal biopsy consistent with celiac disease.

CONCLUSION

i-SCAN-HDWI endoscopy can reflect the histological severity of celiac disease more accurately than conventional WLE alone. This novel endoscopic imaging can improve the diagnostic yield of duodenal biopsies in celiac patients, especially for those with a patchy distribution of villous damage.

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.