Technique for endoscopic submucosal dissection (ESD)

This patient with a lesion suspicious for early gastric cancer was referred for endoscopic resection. On examination with high-definition white light, the lesion was 15 mm in diameter, classified as IIa, and was located on the anterior wall of the lower third of the gastric body (A). We used indigo carmine dye spraying to delineate the lesion's margin (B). Next, we marked the periphery of the lesion using electrocautery (C). We then performed submucosal injection and mucosal incision (D). We made a circumferential incision with an electrosurgical knife to separate the lesion from the underlying normal tissue (E). Next, we performed submucosal dissection (F). Total exposure of the muscle layer was accomplished in 20 minutes (G). The lesion was fixed before immersion in formaldehyde (H). Histopathologic analysis revealed low-grade dysplasia with negative margins.