This is a spontaneous, prospective, monocentric, observational, cohort study, with the aim of evaluating the effect of ultrasound-guided endoscopic fundoplication using the Medigus Ultrasonic Surgical Endostapler (MUSESystem; MediGus, Ltd. Israel) in patients with esophageal or extra-esophageal gastro-oesophageal reflux disease (GERD)-related symptoms. The end of the study will be at the end of the 6-year follow-up of the last patient enrolled. The study proposes the following objectives: * Primary objective: to evaluate the efficacy of endoscopic fundoplication with MUSE for the treatment of GERD, through clinical experience, in terms of: * effect on GERD-Health Related Quality of Life (HRQL) and Reflux Symptom Index (RSI) questionnaire scores * effect on the use and dosage of proton pump inhibitors (PPI) * feasibility and safety of the endoluminal fundoplication procedure * Secondary objective: to characterize the treated patient population (demographic and objective data) and to identify the successful predictors of the procedure. The study design includes the following phases: \*Preliminary patient evaluation and verification of inclusion criteria through: Upper GI endoscopy Esophageal high-resolution manometry 24-hours esophageal pH-impedance OFF PPI PPI use GERD-HRQL and RSI questionnaires scores OFF PPI * 6-month follow-up: Upper GI endoscopy Esophageal high-resolution manometry 24-hours esophageal pH-impedance OFF PPI PPI use GERD-HRQL and RSI questionnaires scores OFF PPI * 12-months follow-up: Upper GI endoscopy 24-hours esophageal pH-impedance OFF PPI PPI use GERD-HRQL and RSI questionnaires scores OFF PPI * Yearly clinical follow-up (up to 6 years): PPI use GERD-HRQL and RSI questionnaires scores OFF PPI