Endoscopic transgastric lymphadenectomy by using EUS for selection and guidance

Background: EUS-guided fine needle aspiration (EUS-FNA) is a reliable tool for tissue diagnosis of unexplained mediastinal or perigastric lymphadenopathy but may be ineffective in sampling a small malignant focus in it or removing an entire node. Objective: To develop a new EUS-guided endoscopic-transgastric method to approach (sentinel) lymph nodes, including node marking and lymphadenectomy. Design: Experimental study. Setting: Animal experiments at an approved University college. Subjects: Six pigs had a linear-array EUS examination 1 week after a transgastric procedure. All had reactive perigastric lymph nodes. Interventions: Selected nodes were punctured with a 19-gauge EUS needle. A metal anchor with thread, loaded onto the needle, was placed across the lymph nodes to pull the node toward the stomach. After gastric-wall dissection with a needle knife at the point of emergence of the thread, the nodes were removed by pulling on the thread and the anchor. The gastric incision was closed with an endoscopic suturing system. Main Outcome and Measurements: Proof of the feasibility to endoscopically remove paragastric lymph nodes by an EUS-guided transgastric approach. Results: In all pigs, lymph-node marking with an anchor and thread was possible. Traction exerted on these nodes showed that they could be pulled against the gastric wall for subsequent removal. In 2 of 6 examinations, the entire sequence of the procedure, node tagging, gastric-wall incision, lymphadenectomy, and wall closure was performed. No serious complication occurred. Limitations: Animal study throughout, small numbers, no humans to date. Conclusions: Transgastric lymphadenectomy with EUS for node selection and capturing seems feasible.