The Nissen Sleeve technique consists of creating a gastric total fundoplication (Nissen technique) before to perform the removal of 2/3 of the stomach (SLEEVE technique), intends for decrease the rate of gastroesophageal reflux disease (GERD). This study aims to evaluate the influence of the Nissen Sleeve technique on GERD. However, the Ezisurg easyEndoTM Linear Cutting Stapler and Loading Units for Single Use were used in this study, and its safety and performance could be evaluated at the same time.

Inclusion Criteria

• Body Mass Index (BMI) ≥ 30 kg/m² (or BMI ≥ 27 kg/m² with at least one obesity-related comorbidity, e.g., type 2 diabetes, hypertension, dyslipidemia).
• Medically eligible for laparoscopic sleeve gastrectomy (LSG) or Nissan sleeve surgery, as determined by a multidisciplinary bariatric team (e.g., surgeon, endocrinologist, dietitian).
• Ability to understand and voluntarily sign written informed consent.
• Willingness to comply with post-operative follow-up protocols (e.g., dietary monitoring, clinical visits, laboratory tests).

Exclusion Criteria

• BMI < 30 kg/m² (or < 27 kg/m² without obesity-related comorbidities).
• Contraindications to laparoscopic surgery (e.g., severe abdominal adhesions, hemodynamic instability, uncorrected coagulopathy).
• History of major gastrointestinal surgery (e.g., gastric bypass, colectomy) or anatomical abnormalities precluding sleeve gastrectomy.
• Active or uncontrolled chronic diseases (e.g., end-stage renal disease, cirrhosis, metastatic cancer, severe cardiovascular disease).
• Psychiatric disorders limiting adherence to post-operative care (e.g., severe depression, psychosis, substance use disorder).
• Pregnancy or breastfeeding (or plans for pregnancy within 12 months post-surgery).
• Allergy or intolerance to surgical materials, anesthesia, or post-operative medications required for the study.
• Inability to communicate or cooperate with study procedures (e.g., language barriers, cognitive impairment).