The magnetic sphincter augmentation (MSA) device was initially implanted with minimal hiatal dissection (MHD) at the diaphragmatic hiatus. Due to concern of possible MSA device dysfunction if herniated into an occult or small hiatal hernia, and increased understanding to the role of defective crura in reflux disease, the operative procedure was changed to planned obligatory dissection (OD) of the hiatus at the time of all implantations. Between December 2012 and September 2016, 182 patients underwent MSA implant at a single medical center and have complete records available for review through September 2017. The MHD dissection period extended from December 2012 to September 2015, from September 2015 to 2016 all patients underwent OD. MHD occurred 53% (96/182) versus OD in 47% (86/182), mean follow-up time in days for MHD and OD was 554 (SD 427) versus 374 (298)days. Intraoperative measurement of hernia size for the MHD versus OD was 0.77 (1.1) versus 3.95 (2.4)cm, p < 0.001. At first visit follow-up, there was no difference in any dysphagia (p = 0.11). Recurrent GERD (defined as resumption of PPI after successful initial post-operative wean) was less frequent after OD than after MHD, 3.6 versus 16.3%, p = 0.006. Delayed onset dysphagia was 1.2% in the OD group versus 8.6% in the MHD group, p = 0.04. Recurrent hiatal hernia of 2cm or greater occurred in 0.0% of the OD and 11.5% of the MHD, p = 0.03. Repeat surgery for hiatal hernia repair has occurred in 0% of the OD and 6.6% of the MHD, p = 0.02. OD of the hiatus with crural closure resulted in less recurrence of reflux symptoms and hiatal hernia, despite an increased proportion of patients with larger hiatal hernia and more complex anatomic disease at the time of operation.