Endoscopic submucosal tunnel dissection salvage technique for ulcerative early gastric cancer

Figure 1 Endoscopic images. A: Ulcerative early gastric cancer on the anterior wall of the proximal antrum; B: Radial endoscopic ultrasonography revealed an irregular heterogeneous hypoechoic lesion with smooth tapering in the third layer of the gastric wall with indication that the cancer had invaded the superficial submucosal layer (arrow).

Figure 2 Key procedures of the endoscopic submucosal tunnel dissection salvage technique. A: An area surrounding the early gastric cancer (EGC) lesion and tunnel gate is marked with argon plasma coagulation; B: A solution containing saline and sodium hyaluronate with diluted epinephrine and indigo carmine is injected into the submucosal layer around the EGC lesion and tunnel area; C: A hook knife is used to make an incision at the tunnel gate and a circumferential incision surrounding the lesion; D: A tunnel dissection of the EGC lesion is made with a hook knife and an endoscopic submucosal dissection cap; E: The EGC margin is confirmed and the lesion is directly dissected; F: The resected lesion and the overlying tunnel mucosae are removed without clipping.

Figure 3 Endoscopic submucosal tunnel dissection salvage technique. Endoscopic images showing; A: Marking of the surrounding the early gastric cancer (EGC) lesion and tunnel gate; B: Submucosal injection and incision of the tunnel gate; C: Initiation of tunnel dissection from tunnel gate; D: Tunnel dissection with hook knife and an endoscopic submucosal dissection cap; E: Direct dissection of EGC; F: En bloc resection.

Figure 4 Histopathology findings. Hematoxylin and eosin staining of a biopsy sample (case 1) revealed the presence of a well-differentiated tubular carcinoma invading the muscularis mucosa (arrow) (magnification × 100) (A) and lesion was composed of predominantly discrete glands with pseudostratified hyperchromatic nuclei and some fused glands (magnification × 200) (B).