fig6

Figure 6. The pocket-creation method (PCM) of endoscopic submucosal dissection (ESD) for a locally recurrent tumor in the rectosigmoid portion. (A) A laterally spreading tumor approximately 8 cm in diameter. (B) The small-caliber-tip transparent (ST) hood entered the submucosal space below the tumor. Although using an ST hood with a small orifice, the entire view is secured through the transparent wall of the ST hood. A focal submucosal scar resulting from one of multiple biopsies performed at a local hospital was identified in the pocket. (C) The white surface of the muscularis was clearly identified distinguishing the blue submucosal layer in the pocket. (D) Perforating blood vessels were identified very clearly in the pocket so that they were precisely coagulated without immediate bleeding. (E) There was severe submucosal fibrosis due to previous multiple piecemeal endoscopic mucosal resections in the central area of the tumor. (F) After dissecting the fibrosis, the tip of the endoscope reached a less fibrotic area beyond the fibrosis. The submucosal pocket was subsequently opened. The ESD was completed in 211 min without any adverse events. (G) A mucosal defect after the ESD did not have any thermal damage. (H) The back of the ESD specimen showed a white severe fibrotic area. (I) The resected specimen and the tumor were 105 mm × 87 mm, and 82 mm × 75 mm in size, respectively. Pathology revealed a high-grade adenoma with a negative margin.