No_intervention: Surgeon blinded

During blinded cases no adjustment will be made to the surgical procedure based on EndoFLIP results, as the operating surgeon will not be informed of the measured values.~Surgery will be scheduled and patients will undergo intraoperative impedance planimetry with EndoFLIP obtaining measurements of the cross-sectional area, balloon pressure, minimum diameter, compliance, length of high pressure segment, and distensibility index of the EGJ using an 8cm EndoFLIP balloon. Sequential assessments will be performed to 30ml and 40ml for up to a minute for each volume of distension. An initial baseline measurement will be obtained after establishment of pneumoperitoneum. A second measurement will occur following hiatal dissection and mobilization but prior to crural closure. Two additional measurements will be obtained after hiatal closure and after fundoplication.

Experimental: Surgeon unblinded

The surgeon will be able to augment the surgical intent based on EndoFLIP measurements, such as adding or removing hiatal sutures or repeating the fundoplication. The data will be evaluated to assess if intraoperative calibration influences postoperative symptoms by comparing the two groups.~Surgery will be scheduled and patients will undergo intraoperative impedance planimetry with EndoFLIP obtaining measurements of the cross-sectional area, balloon pressure, minimum diameter, compliance, length of high pressure segment, and distensibility index of the EGJ using an 8cm EndoFLIP balloon. Sequential assessments will be performed to 30ml and 40ml for up to a minute for each volume of distension. An initial baseline measurement will be obtained after establishment of pneumoperitoneum. A second measurement will occur following hiatal dissection and mobilization but prior to crural closure. Two additional measurements will be obtained after hiatal closure and after fundoplication.