Amber‑red color imaging (ACI) is a novel image‑enhanced endoscopic modality designed to improve visualization of blood‑rich and submucosal structures. This study aimed to evaluate whether ACI improves in a clinical setting the clarity of identification of submucosal vessels, submucosal and muscle layers compared with white light imaging (WLI) in a standardized, video‑based setting.

In this prospective video‑based study, third-space endoscopy clips, including endoscopic submucosal dissections (ESD) and peroral endoscopic myotomies (POEM), were analyzed. Each clip included matched WLI and ACI segments in randomized order. Six expert and six non‑expert endoscopists independently rated vessel, submucosal and muscle layer clarity on a 10‑point Likert scale.

Clips from 35 ESD and 20 POEM were analyzed. For submucosal vessels mean scores improved from 7.33 ± 0.89 to 8.55 ± 0.85 for non‑experts and from 7.96 ± 0.86 to 9.63 ± 0.51 for experts (both p<0.001); non‑experts with ACI outperformed experts with WLI (p<0.01). For submucosal layer non‑experts improved from 6.37 ± 1.51 to 8.14 ± 1.29, and experts from 7.82 ± 0.87 to 9.80 ± 0.40 (both p<0.001), with non‑experts achieving expert WLI performance (p=0.2). For muscle layer non‑experts improved from 5.31 ± 1.16 to 7.12 ± 1.17, and experts from 7.75 ± 0.73 to 9.51 ± 0.57 (both p<0.001).

ACI enhances recognition of submucosal vessels, submucosal and muscle layers in ESD and POEM, benefiting both experts and non‑experts, and may serve as a valuable adjunct in third‑space endoscopy.