417 Lack of Peristaltic Reserve as Detected by Multiple Rapid Swallows on HRM Predicts Development of Dysphagia Following Magnetic Sphincter Augmentation for GERD

Abstract

INTRODUCTION: Magnetic Sphincter Augmentation (MSA) is an antireflux procedure that can be performed on patients with normal esophageal motor function. The most common side-effect of MSA is dysphagia, which occurs in 34-38% of patients and may require dilation (Lipham JC et al, 2015). Multiple rapid swallows (MRS) is a provocative maneuver during high resolution esophageal manometry (HRM) that assesses peristaltic reserve; impaired MRS has previously been shown to predict the development of dysphagia following fundoplication (Shaker A et al, 2013). We hypothesized that impaired MRS may predict which patients experience dysphagia following laparoscopic MSA. METHODS: Retrospective review of all patients who underwent MSA at a tertiary academic center from May 2015 to May 2018. All patients completed a standardized esophageal questionnaire and pre-operative HRM which included MRS. Peristaltic augmentation with MRS was defined as a ratio >1 of the distal contractile integral (DCI) following MRS and the median DCI of the 10 baseline wet swallows. Demographics, MSA implant size, and symptom data from post-operative follow-up of at least 6 months was gathered on all patients. RESULTS: 29 patients (age 52 ± 17 years, 59% female, BMI 25 ± 4.2 kg/m2) were identified. Postoperatively, 15 patients developed dysphagia, 9 of them within the first 2 weeks. 5 patients required balloon dilatation for symptom relief. Among the patients that did not develop dysphagia, peristaltic augmentation with MRS was present in 42.9% compared to 6.7% of patients who developed dysphagia (P-value 0.03). 40% of the patients that required balloon dilatation exhibited complete absence of any smooth muscle contraction following MRS (DCI = 0). Having a small MSA implant (13 or 14 beads) versus a large MSA implant (15, 16 or 17 beads) trended towards an association with developing dysphagia (47% versus 29%, P-value 0.18). The DCI ratio of MRS/wet swallows that predicted development of dysphagia following MSA was 0.59. CONCLUSION: Intact peristaltic reserve, as assessed by augmented contraction following MRS, was protective of developing dysphagia following MSA. MRS should be given important consideration in the evaluation of patients under consideration for antireflux surgery specifically with regards to counseling patients on their individual risk of developing dysphagia and the potential need for additional procedures such as dilation.