There is an increasing interest in High resolution manometry (HRM) in the preoperative assessment of patients with obesity, in order to identify the best surgical option. Sleeve gastrectomy (SG) has been known to increase the risk of gastro-esophageal reflux disease (GERD). Different techniques have been recently developed and validated to offer to these patients protection against pathologic GERD after SG.

A recent study found a significant correlation between straight leg raise (SLR) maneuver during HRM and a positive pH-study. However, these maneuver has not been validated in an obese population, therefore the normality cut-off remain unknown.

A multicenter study with a large number of patients undergoing pre-operative assessment for bariatric surgery could provide a precise threshold to predict pathologic esophageal acid exposure time.

Inclusion Criteria:

• Complete and adequate HRM and pH-impedance study performed within 2 weeks
• Successfully performed SLR maneuver (adequate intra-abdominal pressure augmentation)
• Obese with BMI>35 Kg/m2

Exclusion Criteria:

• Patients under the age of 18
• Patients with prior foregut surgery
• Paraesophageal hiatal hernia
• Scleroderma
• Eosinophilic esophagitis
• Pregnancy

Obese patients with thorough pathophysiologic evaluation with or without suspect of GERD