Siewert type II/III gastroesophageal junction (GEJ) adenocarcinoma is a challenging malignancy located at the anatomical transition between the esophagus and stomach. Due to its complex anatomical location and mixed biological characteristics of esophageal and gastric cancers, the optimal surgical strategy remains controversial. Current surgical approaches vary in terms of operative access, extent of resection, and lymph node dissection. Although minimally invasive laparoscopic and integrated robotic surgery have demonstrated potential advantages in improving perioperative outcomes, limitations remain when managing complex procedures involving both abdominal and mediastinal fields.
Split-type robotic surgical systems, characterized by independently movable robotic carts, provide greater flexibility in robotic arm positioning and may overcome some limitations associated with conventional integrated robotic platforms, particularly in extensive multi-quadrant procedures requiring simultaneous abdominal and mediastinal lymph node dissection. However, clinical evidence regarding the safety and effectiveness of split-type robotic surgery for Siewert type II/III GEJ cancer remains limited.
This prospective single-arm clinical study aims to evaluate the feasibility, safety, and short-term surgical outcomes of split-type robotic radical surgery for patients with Siewert type II/III GEJ adenocarcinoma. The study will assess perioperative outcomes, including operative characteristics, postoperative complications, lymph node dissection quality, and short-term recovery parameters. The findings of this study are expected to provide preliminary clinical evidence regarding the application of split-type robotic technology in complex GEJ cancer surgery and support future large-scale clinical investigations.
Age between 18 and 80 years, inclusive, regardless of sex.
Histologically and/or cytologically confirmed Siewert type II or type III gastroesophageal junction tumor, with clinical staging according to AJCC 8th edition TNM classification indicating suitability for curative surgical resection.
Adequate organ function as assessed by the investigator before surgery.
Provision of written informed consent and willingness to participate in the study.
Patients with body mass index (BMI) <18.5 kg/m² or BMI ≥35 kg/m².
Patients with severe cardiac, pulmonary, neurological, hepatic, or renal diseases that may prevent tolerance of surgery or anesthesia.
Patients unable to tolerate pneumoperitoneum or considered by the investigator to have extensive intra-abdominal adhesions or other conditions preventing safe establishment of pneumoperitoneum.
Patients with severe coagulation disorders that contraindicate minimally invasive surgery.
Single group
Robotic-assisted radical resection for Siewert type II/III gastroesophageal junction cancer
Procedure/SurgeryPatients will undergo totally robotic-assisted radical surgery for Siewert type II/III gastroesophageal junction cancer. The surgical procedure includes robotic-assisted tumor resection and lymph node dissection according to standard oncologic principles.
Rate of Successful Completion of Robotic Surgery Without Conversion
The proportion of patients who successfully complete radical resection using the Carina modular robotic surgical system without conversion to conventional laparoscopy or open surgery. Conversion includes unplanned transition to another surgical approach due to technical difficulties, intraoperative complications, or inability to complete the planned robotic procedure.
Incidence of Perioperative Complications (Clavien-Dindo Classification)
The incidence and severity of postoperative complications occurring within 30 days after surgery, classified according to the Clavien-Dindo grading system. Complications include surgical and medical adverse events occurring during the perioperative period.
Achievement Rate of D2 Lymphadenectomy
The proportion of patients achieving complete D2 lymph node dissection according to the Japanese Gastric Cancer Treatment Guidelines. The adequacy of lymphadenectomy will be assessed based on intraoperative findings and postoperative pathological examination.
Number and Metastatic Rate of Lymph Nodes in the Lower Mediastinal and Suprapancreatic Regions
The number of harvested lymph nodes and the proportion of metastatic lymph nodes in specific anatomical regions, including lower mediastinal lymph nodes and suprapancreatic lymph nodes, will be evaluated based on postoperative pathological examination.
Postoperative Pathological Stage (pTNM Classification)
The pathological tumor stage will be determined according to the 8th edition of the American Joint Committee on Cancer (AJCC) TNM staging system.
R0 Resection Rate
The proportion of patients achieving complete tumor resection with microscopically negative margins (R0 resection) according to postoperative pathological examination.
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