Clinical Research Directory

Inclusion Criteria: * Pathologically confirmed gastric adenocarcinoma by biopsy * Carcinoma of the upper gastric body or Siewert type II/III adenocarcinoma of the esophagogastric junction (AEG), with a clinical stage of cT1-3N0-1M0 * Age 18-75 years, with a performance status (PS) score of 0-2 * Candidates for planned surgical resection, eligible for either double-tract reconstruction or tubular gastric anastomosis based on preoperative assessment * No severe dysfunction of vital organs (liver, kidney, heart, lung, or brain), and no severe infection or uncontrolled chronic diseases Exclusion Criteria: * Presence of other malignant tumors or severe chronic diseases (e.g., severe diabetes mellitus, chronic kidney disease, decompensated cirrhosis, etc.) * Preoperative endoscopic diagnosis of Barrett's esophagus * Severe preoperative malnutrition (albumin \<30 g/L, prealbumin \<150 mg/L) * History of prior upper abdominal surgery, gastrointestinal malformation, or psychiatric disorders * Preoperative diagnosis of obstructive motor disorders of the cardia (including achalasia spectrum disorders) * Inability to cooperate with or complete the required postoperative examinations