Autofluorescence imaging endoscopy for predicting acid reflux in patients with gastroesophageal reflux disease

Abstract

Background and Aim Endoscopic diagnosis of gastroesophageal reflux disease (GERD) remains challenging. Autofluorescence imaging (AFI) can identify indistinct mucosal lesions; however, its ability to diagnose GERD has not been determined. This study aimed to compare the diagnostic capabilities of standard white light imaging (WLI) and AFI using pH/impedance testing as gold standard. Methods In this prospective observational trial, 95 consecutive patients with classic reflux symptoms were screened in two tertiary care referral hospitals and 82 were included. GerdQ questionnaire was administered to each patient. Endoscopy with WLI and AFI, and ambulatory 24‐h pH/impedance monitoring were performed. Erosive esophagitis on WLI was defined as positive for GERD, whereas on AFI endoscopy, the appearance of one or more longitudinal purple lines > 1 cm was defined as indicative of GERD. We assessed the diagnostic capacities of each method, as well as inter‐observer agreement on AFI findings. We also looked at factors associated with having a positive AFI finding. Results The sensitivity and accuracy of AFI (77% and 67%, respectively) in detecting GERD were higher than those of WLI (21% and 52%, respectively), although the specificity of AFI (53%) was lower than that of WLI (97%); McNemar test showed a significant difference (P = 0.000). Inter‐observer reliability analysis of AFI findings indicated substantial agreement (Kappa = 0.630, P = 0.000). Multivariate analysis showed that abnormal AFI findings significantly correlated with positive pH/impedance result (odds ratio = 0.242, 95% confidence interval = 0.087–0.673, P = 0.007). Conclusions AFI can reveal GERD‐related mucosal changes, invisible on conventional WLI, thus improve the endoscopic diagnosis of GERD.

Advanced endoscopic imaging: European Society of Gastrointestinal Endoscopy (ESGE) Technology Review

“…Interobserver and intraobserver reproducibility also was improved with NBI, because of better depiction of small erosive foci [85]. I-SCAN showed significantly improved diagnosis of reflux esophagitis (• " Fig.6c) compared to WLE (30 % vs. 22 %, respectively), as well as improved detection of minimal reflux changes (12 % vs. 6 %, respectively) [86] For detecting GERD in 82 patients, AFI showed higher sensitivity and accuracy compared to WLE (77 % and 67 % vs. 21 % and 52 %, respectively), but lower specificity (53 % vs. 97 %) [87].…”

Diagnostic accuracy of gastroesophageal reflux disease questionnaire for gastroesophageal reflux disease: A systematic review and meta‐analysis

“…2,15,18,20,22 Meanwhile, in five studies, subjects were instructed to undergo washout periods by stopping their PPI intakes 1-2 weeks before enrollment. 19,21,23,25,26 PPI usage can affect esophageal inflammation and thus cause changes in esophageal mucosal lesions and severity of GERD symptoms on follow-up, which could influence our study findings. 29 Third, despite attempting to explain potential sources of between-study heterogeneity through subgroup and sensitivity analysis, there were still some residual unexplained heterogeneity, which could be contributed by the differences in the definition of conclusive GERD evidence used between studies (i.e., the use of Lyon consensus to make a consistent definition of GERD, which could increase homogeneity between studies).…”

“…15 The flow diagram of study selection is presented in Figure 1. Twelve of the studies were prospective studies, while the remainder was a cross-sectional study 16 and a retrospective study 17 ; more than half (8/14) of the studies were done in Asian countries, [15][16][17][18][19][20][21][22] while the rest were mostly from Western countries 2,23-27 (Table 1). For the reference test, five studies used only upper endoscopy, [15][16][17][18]22 four studies used only pH monitoring/ impedance, 19,23,26,27 and five studies used both upper endoscopy and pH monitoring/impedance 2,20,21,24,25 (Table S3).…”

“…Twelve of the studies were prospective studies, while the remainder was a cross-sectional study 16 and a retrospective study 17 ; more than half (8/14) of the studies were done in Asian countries, [15][16][17][18][19][20][21][22] while the rest were mostly from Western countries 2,23-27 (Table 1). For the reference test, five studies used only upper endoscopy, [15][16][17][18]22 four studies used only pH monitoring/ impedance, 19,23,26,27 and five studies used both upper endoscopy and pH monitoring/impedance 2,20,21,24,25 (Table S3). Studies using only upper endoscopy as the reference test can differentiate ERD and non-ERD, studies using only pH monitoring/impedance can only detect abnormal acid exposure, while studies utilizing both upper endoscopy and pH monitoring/impedance can detect ERD, NERD, and normal patients.…”

Recent Advances and the Potential for Clinical Use of Autofluorescence Detection of Extra-Ophthalmic Tissues

“…The ability of AFI to detect mucosal inflammation of the esophagus was investigated by Wang et al in 82 patients undergoing assessment for gastroesophageal reflux disease (GERD) [8]. Compared to standard WLE, AFI showed higher sensitivity and accuracy in detecting mucosal inflammation (sensitivity: 77% vs. 21%, accuracy: 67% vs. 52%) [8]. Whether AFI can distinguish patients with pathologic non-erosive reflux disease (NERD) from those with functional heartburn (FH) was investigated by Luo et al [9].…”