Successful endoscopic submucosal dissection for a tumor located completely within a colonic diverticulum after inversion of the diverticulum using a traction device.

Video 1Successful endoscopic submucosal dissection for a tumor completely located within a colonic diverticulum after inversion of the diverticulum using a traction device. After reconfirming that the diverticulum could be inverted into the lumen with forceps, the first endoclip grasping a ring-thread made of dental floss was fixed on the mucosa in the diverticulum. Immediately afterward, a second endoclip was used to grasp the ring-thread and fix it to the opposite colonic wall. By insufflating with air, the lesion within the inverted diverticulum was pulled out of the diverticulum into the colonic lumen, establishing a good field of view for dissection. After local injection of hyaluronic acid, a circumferential incision and dissection were performed using a DualKnife, and the lesion was promptly removed en bloc. The wound was completely closed with endoclips, along with the diverticulum. The total procedure time was 10 minutes, and there were no adverse events.