Compare the Oncological Benefit of Deep Neuromuscular Block in Gastric Cancer Obesity Patient

This study is designed to evaluate the impact of muscle relaxation during laparoscopic gastrectomy on oncological benefit, especially with obese patients over BMI 25. This is a randomized controlled trial comparing deep NMB with moderate NMB in laparoscopic subtotal gastrectomy in obese patients with gastric cancer. The design of the study is blinded (the surgical team and the research team are all blinded to the treatment); the attending anesthesiologist is not blinded. The primary endpoint is number of harvested lymph node that is critical point regarding quality of surgery in gastric cancer treatment. The secondary endpoint is intraoperative bleeding, surgeons' satisfaction. The patients were randomly assigned to two groups using a computer-generated randomization table : 196 persons * Deep neuromuscular block group (98persons) * Moderate neuromuscular group (98persons) The patients are assigned to the deep NMB group or the moderate NMB group. The clinical research coordinator (CRC) uses a computer randomization program to determine the degree of muscle relaxation of each patient. Stratified block randomization is used to guarantee even distribution, which means that all participating hospitals are assigned moderate or deep NMB randomly in a 1:1 ratio. The CRC notifies the anesthesiologist of the degree of muscle relaxation just before the operation. Surgeons are blinded to the degree of muscle relaxation: They can enter the operating room after the muscle relaxation has been performed. A train-of-four (TOF) monitor is placed out of the surgeon's visual field. The anesthesiologist injects sugammadex after confirming the absence of the surgeon. The ward staff members who evaluate patient outcomes are blinded to the degree of muscle relaxation.