Optimal concentration of Lugol's solution for detecting early esophageal carcinoma: A randomized controlled trial.

BACKGROUND AND AIM: Lugol chromoendoscopy is the standard technique to detect an esophageal squamous cell carcinoma (ESCC). However, a high concentration of Lugol's solution can induce mucosal injury and adverse events. We aimed to investigate the optimal concentration of Lugol's solution to reduce mucosal injury and adverse events without degrading image quality. METHODS: This was a two-phase double-blind randomized controlled trial. In phase I, 200 eligible patients underwent esophagogastroduodenoscopy and then were randomly (1:1:1:1:1) sprayed with 1.2%, 1.0%, 0.8%, 0.6%, or 0.4% Lugol's solution. Image quality, gastric mucosal injury, adverse events, and operation satisfaction were compared to investigate the minimal effective concentration. In phase II, 42 cases of endoscopic mucosectomy for early ESCC were included. The patients were randomly assigned (1:1) to the minimal effective (0.6%) or conventional (1.2%) concentration of Lugol's solution for further comparison of the effectiveness. RESULTS: In phase I, the gastric mucosal injury was significantly reduced in 0.6% group (P < 0.05). Furthermore, there was no statistical significance in image quality between 0.6% and higher concentrations of Lugol's solution (P > 0.05, respectively). It also showed that the operation satisfaction decreased in 1.2% group compared with the lower concentration groups (P < 0.05). In phase II, the complete resection rate was 100% in both groups, while 0.6% Lugol's solution showed higher operation satisfaction (W = 554.500, P = 0.005). CONCLUSIONS: The study indicates that 0.6% might be the optimal concentration of Lugol's solution for early detection and delineation of ESCC, considering minimal mucosal injury and satisfied image. The registry of clinical trials: ClinicalTrials.gov (NCT03180944).

Impact of a real-time automatic quality control system on colorectal polyp and adenoma detection: a prospective randomized controlled study (with videos).

BACKGROUND AND AIMS: Quality control can decrease variations in the performance of colonoscopists and improve the effectiveness of colonoscopy to prevent colorectal cancers. Unfortunately, routine quality control is difficult to carry out because a practical method is lacking. The aim of this study was to develop an automatic quality control system (AQCS) and assess whether it could improve polyp and adenoma detection in clinical practice. METHODS: First, we developed AQCS based on deep convolutional neural network models for timing of the withdrawal phase, supervising withdrawal stability, evaluating bowel preparation, and detecting colorectal polyps. Next, consecutive patients were prospectively randomized to undergo routine colonoscopies with or without the assistance of AQCS. The primary outcome of the study was the adenoma detection rate (ADR) in the AQCS and control groups. RESULTS: A total of 659 patients were enrolled and randomized. A total of 308 and 315 patients were analyzed in the AQCS and control groups, respectively. AQCS significantly increased the ADR (0.289 vs 0.165, P < .001) and the mean number of adenomas per procedure (0.367 vs 0.178, P < .001) compared with the control group. A significant increase was also observed in the polyp detection rate (0.383 vs 0.254, P = .001) and the mean number of polyps detected per procedure (0.575 vs 0.305, P < .001). In addition, the withdrawal time (7.03 minutes vs 5.68 minutes, P < .001) and adequate bowel preparation rate (87.34% vs 80.63%, P = .023) were superior for the AQCS group. CONCLUSIONS: AQCS could effectively improve the performance of colonoscopists during the withdrawal phase and significantly increase polyp and adenoma detection. (Clinical trial registration number: NCT03622281.).

Cresyl violet as a new contrast agent in probe-based confocal laser endomicroscopy for in vivo diagnosis of gastric intestinal metaplasia.

BACKGROUND AND AIM: Cresyl violet (CV) is a topical dye that allows simultaneous chromoendoscopy and in vivo confocal laser endomicroscopy in identification of neoplastic changes of the lower gastrointestinal tract without intravenous injection of fluorescein, but as yet no investigation has reported its application in the diagnosis of gastric intestinal metaplasia (GIM). This study aims to assess the feasibility as well as diagnosis accuracy of topical CV for in vivo diagnosis of GIM by using probe-based confocal laser endomicroscopy (pCLE). METHODS: In this prospective, open-label, feasibility study, 129 confocal videos from 22 patients with known GIM were analyzed and compared with corresponding histological images to establish the CV staining characteristics. In addition, 47 patients with known or suspected GIM were prospectively enrolled to evaluate the accuracy of this topical CV endomicroscopic imaging. RESULTS: Probe-based confocal laser endomicroscopy with topical CV enabled clear visualization of the goblet cells, absorptive cells, and intestinal villi of GIM. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of pCLE diagnosis of GIM on a per-location analysis was 93.01%, 91.95%, 93.51%, 86.96%, and 96.11%, respectively. The intraclass correlation coefficient for inter-observer agreement and mean kappa value for intra-observer agreement for the diagnosis of GIM was 0.82 and 0.87, respectively. CONCLUSIONS: Topical CV enables real-time chromoendoscopy in conjunction with pCLE examination of the stomach and warrants accurate diagnosis of GIM. It may be an acceptable and potentially alternative dye for confocal imaging in the future.