Snare traction-assisted ultra-long tunnel endoscopic resection of a giant exophytic cardia subepithelial tumor with diaphragmatic adherence

The incidental finding on the contrast-enhanced computed tomography scan (Fig. 1 a) of a 31-year-old man was as follows: an irregular soft-tissue mass located between the gastric fundus-cardia and the hepatogastric space. Gastroscopy (Fig. 1 b) revealed a submucosal bulge on the posterior wall of the cardia. Endoscopic ultrasound (Fig. 1 c) demonstrated a hypoechoic lesion arising from the muscularis propria, with clear margins and abundant peripheral blood flow (Video 1). A therapeutic gastroscope fitted with a transparent cap was used to create a submucosal tunnel in the esophageal wall 3 cm proximal to the lesion on the posterior cardia wall, exposing a milky white tumor (Fig. 2 a). Dissection with an ITknife2 revealed an exophytic, complex, multifocal mass extending into the peritoneal cavity; standard tunnel vision was limited. An endoscopically introduced snare was tightened around part of the tumor with hemostatic forceps, and continuous traction toward the esophageal lumen (Fig. 2 b) provided panoramic exposure of the peritumoral plane. Meticulous dissection freed the tumor from surrounding connective tissue and severed its continuity with the gastric muscularis propria, while simultaneous right upper-quadrant needle decompression prevented pneumoperitoneum. Adhesions to the diaphragm were carefully released under traction. The intact specimen (≈ 8 × 2 cm, irregular) was extracted through the tunnel orifice (Fig. 2 c). Postoperative wound hemostasias was achieved (Fig. 2 d), and the tunnel entry was closed with seven metal clips. Histopathology confirmed leiomyoma. Postoperative recovery was uneventful, with no hemorrhage or perforation.