Endoscopic and Fluoroscopic Landmarks for Preventing Pyloric Obstruction During Transgastric <scp>LAMS</scp> Deployment in <scp>EUS</scp> ‐Guided Gallbladder Drainage

Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using a lumen-apposing metal stent (LAMS) has become a minimally invasive alternative to cholecystectomy for the management of cholecystitis in high-risk surgical candidates [1]. The optimal puncture route–either transduodenal or transgastric–remains controversial [2] and should be selected according to anatomical proximity, endosonographic visibility, and procedural stability. However, transgastric puncture may result in pyloric ring obstruction when the puncture site is near the pylorus, causing misdeployment of the LAMS [3]. This difficulty arises because the procedure is primarily performed under EUS and fluoroscopic guidance, making it challenging to precisely assess the distance between the pyloric ring and the intended puncture site in real time. We present technical tips for avoiding pyloric ring obstruction during transgastric EUS-GBD. A man in his 80s with unresectable pancreatic head cancer developed obstructive jaundice, for which a multi-hole self-expandable metal stent (MH-SEMS) was placed. Following SEMS placement, he developed acute cholecystitis (Figure 1a). The condition was unresponsive to conservative management; therefore, EUS-GBD was performed. The duodenal bulb showed tumor invasion (Figure 1b), making transduodenal puncture risky. Additionally, scope stability was poor and the landing space within the gallbladder for the inner flange of the LAMS was limited (Figure 1c); a transgastric approach was selected. On EUS imaging, the optimal puncture site was close to the pyloric ring, raising the risk of pyloric obstruction due to misdeployment of the LAMS (Figure 1d,e). To ensure accurate placement, a marking clip was placed near the pylorus for fluoroscopic reference, and strong suction was applied under EUS guidance, leaving a mucosal suction mark as an endoscopic landmark (Figure 2a–c, Video S1). The LAMS was successfully deployed without pyloric obstruction under combined EUS, endoscopic, and fluoroscopic guidance with these markers (Figure 2d,e, Video S2). A double-pigtail stent was inserted to prevent food impaction, and postoperative CT confirmed ideal stent positioning (Figure 2f). Haruka Toyonaga conceptualized and drafted the manuscript. Haruka Toyonaga, Tatsuya Nakagawa, Makoto Masaki, Hidetoshi Nakata, Shoji Takayama, Takuya Takayama, Masahiro Orino, Hironao Matsumoto, and Masaaki Shimatani performed the endoscopic examinations and patient clinical management. Masaaki Shimatani supervised the case, participated in drafting the manuscript, and made intellectual revisions to the manuscript. All authors have read and approved the final version of the manuscript. The authors have nothing to report. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request. Video S1: Pre-procedural assessment and landmark creation for transgastric EUS-GBD. This video presents a case of acute cholecystitis in a patient with unresectable pancreatic head cancer following SEMS placement. Due to duodenal tumor invasion, a transgastric approach was selected. To prevent pyloric obstruction during LAMS deployment, a marking clip was placed near the pylorus for fluoroscopic reference, and a mucosal suction mark was created to visualize the optimal puncture site endoscopically. Video S2: LAMS deployment and post-procedural confirmation. Using the clip and suction marks as landmarks, the LAMS was successfully deployed under combined EUS, endoscopic, and fluoroscopic guidance. The video confirms appropriate flange positioning without pyloric occlusion. A double-pigtail stent was subsequently inserted. Postoperative CT confirmed optimal stent positioning and apposition of the gallbladder and stomach. Best regards, Haruka Toyonaga. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.