S151: impedance planimetry (EndoFLIP™) after magnetic sphincter augmentation (LINX®) compared to fundoplication

Introduction Functional luminal imaging probe (FLIP) use during laparoscopic fundoplication (LF) for gastroesophageal reflux disease is well described. However, there is a lack of data on FLIP measurements during magnetic sphincter augmentation (MSA). This study aims to report our institutional experience in performing FLIP during MSA and to compare these measurements to those obtained during Nissen and Toupet fundoplication. Methods and procedures A retrospective review of a prospectively maintained quality database was performed. Patients who underwent MSA or LF and had FLIP measurements between April 2018 and June 2021 were included. FLIP measurements at the gastroesophageal junction (GEJ) were recorded without pneumoperitoneum at 40 mL balloon fill after hernia reduction, cruroplasty, and MSA or fundoplication. Reflux symptom index (RSI), GERD-HRQL, and dysphagia score were collected up to 2 years. Group comparisons were made using two-tailed Wilcoxon rank-sum and chi(2) tests, with statistical significance of p < 0.05. Results Twenty-seven patients underwent MSA and 100 patients underwent LF (66% Toupet, 34% Nissen). Type III hiatal hernia was present in 3.7% of MSA patients versus over 50% for fundoplication patients. Minimum diameter, cross-sectional area, and distensibility index (DI) were lower after MSA device placement compared to Nissen or Toupet fundoplication (p < 0.05). Postoperative follow-up showed no differences in RSI, GERD-HRQL, and dysphagia score between MSA and Nissen fundoplication (p > 0.05). Conclusion Intraoperative impedance planimetry provided objective information regarding the geometry of the GEJ during MSA. The ring of magnetic beads restores the anti-reflux barrier and transiently opens with food bolus and belching. The magnetic force of the beads may explain why the DI after MSA is lower yet postoperative quality of life is no different than Nissen fundoplication.