A Detailed Evaluation of Intrapapillary Capillary Loops (IPCLS) in GERD Patients Using Narrow Band Imaging (NBI)

Abstract

Background: Pts with GERD may have minimal changes in distal esophagus that may not be visible with conventional endoscopy. NBI is a novel technology that utilizes blue light (shorter wavelength) with special narrow band filter enabling more detailed visualization, especially of the vascular patterns. IPCLs have been reported to be increased in number, tortuous and dilated in GERD pts compared to controls. Aim: To evaluate and compare the following in GERD pts vs controls: IPCLs in the distal esophagus, calculate the max, min and average IPCL in each pt and to plot ROC curves to obtain the number of IPCLs that gives the best sensitivity and specificity for a diagnosis of GERD. Methods: Pts with GERD and controls were evaluated with a magnification endoscope using a NBI. The distal esophagus was examined with NBI (single endoscopist) which provided a striking detail of the capillary patterns- areas with the max and min density of IPCL were noted and photographed. These images were then evaluated by another endoscopist who was blinded to the patient groups and the max, min and average number of IPCLs was recorded. Results between patients with GERD and controls were compared by unpaired t test. ROC curves were plotted for the max, min and average IPCL to determine cut-off numbers with highest sensitivity and specificity. Results: A total of 72 pts were prospectively enrolled; mean age 60.2 years and 67 were males. 3 pts were excluded due to suboptimal quality of images. There were 45 GERD pts and 24 controls. The max, min and average number of IPCLs was significantly greater in the GERD group compared to controls (table 1). ROC curves were plotted for the max, min and average number of IPCLs; sensitivity and specificity values using different cut off numbers for IPCL are shown in table 2. Conclusions: NBI endoscopy provides a detailed visualization of the vascular patterns and IPCL in the distal esophagus. The number of IPCLs is significantly higher in GERD pts compared to controls. By ROC curves, the best sensitivity and specificity for GERD was seen with a max IPCL count of 145, min IPCL count of 97 and an average IPCL count of 122. These findings support an emerging role of NBI documented vascularity in the diagnosis of patients with GERD. Table 1 GERD Controls p Value Mean Maximum 185.4 ± 79.74 122.8 ± 31.21 0.0005 Mean Minimum 128.5 ± 42.41 92.6 ± 27.58 0.0005 Average 156.9 ± 57.55 108.4 ± 26.80 0.0003 Open table in a new tab Table 2 Sensitivity Specificity Maximum IPCL = 145 71% 71% Minimum IPCL = 97 82% 61% Average IPCL = 122 78% 70% Open table in a new tab