Electrical Stimulation Therapy (EST) of the Lower Esophageal Sphincter (GERD)

Inclusion Criteria: * Subject able and willing to provide written informed consent * Subject able and willing to comply with required study procedures and follow-up schedule * Typical symptoms of GERD (regurgitation and/or heartburn) for longer than 6 months, heartburn responding to PPI therapy. Subject may also complain of atypical symptoms of GERD that may persist on PPI * Daily dose of PPI or other acid neutralization drugs because of PPI intolerance * Baseline visit GERD-HRQL score ≥ 20 following 14 days off-PPI and at least 10 points higher than their on-PPI (or other acid-neutralization drugs) GERD-HRQL score recorded during the Screening Visit * Excessive lower esophageal acid exposure during pH monitoring (defined as distal esophageal pH \< 4 for \> 5.0% of the monitoring time) performed after 14 days off PPIs * Subject is a suitable surgical candidate able to undergo general anesthesia and laparoscopic surgery. Exclusion Criteria: * Previous EndoStim LES System implant and/or implant attempt * Previous esophageal surgery, including Nissen fundoplication * Previous endoscopic intervention for the treatment of GERD and/or Barrett's esophagus * Hiatal hernia larger than 2 cm as determined by any diagnostic investigation (i.e., endoscopy, manometry or laparoscopic visualization) * Gastroparesis * Any non-GERD esophageal motility disorders * Esophageal stricture or significant esophageal anatomic abnormalities * Barrett's epithelium or any grade of dysplasia * Documented history of esophagitis Grade C or D (LA Classification) * History of suspected or confirmed esophageal or gastric cancer * Esophageal or gastric varices * Symptoms of dysphagia more than once per week within the last 3 months * Suspected or known allergies to titanium, platinum, iridium, stainless steel, silicone, epoxy, or nylon * Body mass index (BMI) \> 35 kg/m2 * Any significant multisystem diseases * Autoimmune or a connective tissue disorder (scleroderma, dermatomyositis, Calcinosis-Raynaud's-Esophagus Sclerodactyly Syndrome (CREST), Sjogren's Syndrome, Sharp's Syndrome, etc.) requiring therapy in the preceding 2 years * Type 1 diabetes mellitus or uncontrolled Type 2 diabetes mellitus (T2DM) defined as HbA1c \> 9.5 in the previous 6 months or at screening/baseline, or has T2DM for \> 10 years * Significant cardiac arrhythmia or ectopy or significant cardiovascular disease (i.e. unstable angina pectoris, hemodynamically significant valvular disease, severe congestive heart failure), or cardiac therapeutic intervention within the last 6 months. * Significant cerebrovascular event within the last 6 months * Existing implanted electrical stimulator (pacemaker, implantable cardioverter defibrillator, deep brain stimulator (DBS), bone growth or pelvic floor stimulators, drug pumps, etc.) * Chronic anticoagulant therapy * Female subject of child-bearing potential and is pregnant or nursing, or intends to become pregnant during the trial period, who is not using a reliable form of birth control * Subject is currently enrolled in other potentially confounding research * Active infection as determined by the investigator * History of any malignancy in the last 2 years * Life expectancy less than 3 years * Diagnosed major psychiatric disorder (bipolar, schizophrenia, etc.)