The Impact of Magnetic Sphincter Augmentation (MSA) on Esophagogastric Junction (EGJ) and Esophageal Body Physiology and Manometric Characteristics.

OBJECTIVE: To evaluate the impact of MSA on lower esophageal sphincter (LES) and esophageal body using high resolution impedance manometry. BACKGROUND: MSA is an effective treatment in patients with gastroesophageal reflux disease, but there is limited data on its impact on esophageal functional physiology. METHODS: Patients who underwent MSA were approached 1-year after surgery for objective foregut testing consists of upper endoscopy, esophagram, high resolution impedance manometry, and esophageal pH-monitoring. Postoperative data were then compared to the preoperative measurements. RESULTS: A total of 100 patients were included in this study. At a mean follow up of 14.9(10.1) months, 72% had normalization of esophageal acid exposure. MSA resulted in an increase in mean LES resting pressure [29.3(12.9) vs 25(12.3), P < 0.001]. This was also true for LES overall length [2.9(0.6) vs 2.6(0.6), P = 0.02] and intra-abdominal length [1.2(0.7) vs 0.8(0.8), P < 0.001]. Outflow resistance at the EGJ increased after MSA as demonstrated by elevation in intrabolus pressure (19.6 vs 13.5 mmHg, P < 0.001) and integrated relaxation pressure (13.5 vs 7.2, P < 0.001). MSA was also associated with an increase in distal esophageal body contraction amplitude [103.8(45.4) vs 94.1(39.1), P = 0.015] and distal contractile integral [2647.1(2064.4) vs 2099.7(1656.1), P < 0.001]. The percent peristalsis and incomplete bolus clearance remained unchanged ( P = 0.47 and 0.08, respectively). CONCLUSIONS: MSA results in improvement in the LES manometric characteristics. Although the device results in an increased outflow resistance at the EGJ, the compensatory increase in the force of esophageal contraction will result in unaltered esophageal peristaltic progression and bolus clearance.

Efficacy of Magnetic Sphincter Augmentation Across the Spectrum of GERD Disease Severity.

BACKGROUND: The performance and durability of various types of fundoplication are variable when stratified by disease severity. To date, magnetic sphincter augmentation (MSA) has not been evaluated in this context. We designed this study to determine the efficacy of MSA in the treatment of severe GERD. STUDY DESIGN: Guided by previous studies, a DeMeester score (DMS) ≥ 50 was used as a cutoff point to define severe reflux disease. Subjects were divided into 2 groups using this cutoff, and outcomes of severe cases were compared with those with less severe disease (DMS < 50). RESULTS: A total of 334 patients underwent MSA. Patients with severe disease had a higher mean preoperative DMS compared with those with mild to moderate GERD (79.2 [53.2] vs 22.8 [13.7], p < 0.0001). At a mean postoperative follow-up of 13.6 (10.4) months, there was no difference between the mean GERD Health-Related Quality of Life (HRQL) total scores in patients with severe disease compared with those with less severe GERD (8.8 [10] vs 9.2 [10.8], p = 0.9204). Postoperative mean DMS was not different between groups (17.3[23.0] vs 14.1[33.9], p = 0.71), and there was no difference in the prevalence of esophagitis (p = 0.52). Patients with severe disease were less likely to be free from use of proton pump inhibitors after surgery (85% vs 93.1%, p = 0.041). There were similar rates of postoperative dysphagia (10% vs 14%, p = 0.42) and need for device removal (3% vs 5%, p = 0.7463). CONCLUSIONS: MSA is an effective treatment in patients with severe GERD and leads to significant clinical improvement across the spectrum of disease severity, with few objective outcomes being superior in patients with mild-to-moderate reflux disease.

Clinical Outcomes and Predictors of Favorable Result after Laparoscopic Magnetic Sphincter Augmentation: Single-Institution Experience with More than 500 Patients.

BACKGROUND: Magnetic sphincter augmentation (MSA) is a promising surgical treatment for patients with GERD. The aim of this study was to evaluate the outcomes of MSA in a large cohort of patients with GERD and to determine the factors predicting a favorable outcome. METHODS: This was a retrospective review of prospectively collected data of 553 patients who underwent MSA at our institution in a 5-year period. Preoperative clinical, endoscopic, manometric, and pH data were used in a univariate analysis. This was followed by a regression multivariable analysis to determine the factors predicting a favorable outcome. Favorable outcome was defined as freedom from proton pump inhibitors and ≥50% improvement in Gastroesophageal Reflux Disease-Health-Related Quality of Life (GERD-HRQL) total score. RESULTS: At a mean (SD) follow-up of 10.3 (10.6) months after MSA, 92.7% of the patients were free of proton pump inhibitor use and 84% reported at least 50% improvement in their GERD-HRQL total score. The GERD-HRQL total score was improved from a mean (SD) baseline value of 33.8 (18.7) to 7.2 (9.0) (p < 0.001) and 76.1% of the patients had normalization of their esophageal acid exposure. Independent predictors of a favorable outcome after MSA included age younger than 45 years (odds ratio [OR] 4.2; 95% CI, 1.1 to 15.2; p = 0.0305), male sex (OR 2.5; 95% CI, 1.1 to 5.7; p = 0.0301), GERD-HRQL total score >15 (OR 7.5; 95% CI, 3.3 to 16.8; p < 0.0001), and abnormal DeMeester score (OR, 2.6; 95% CI, 1.1 to 5.7; p = 0.0225). CONCLUSIONS: In this largest single-institution series, we demonstrate that MSA implantation is associated with very good clinical and objective outcomes. Age younger than 45 years, male sex, GERD-HRQL total score >15, and abnormal DeMeester score are the 4 preoperative factors predicting a favorable outcome and can be used in patient counseling and MSA use.

Electrical stimulation to increase lower esophageal sphincter pressure after POEM.

INTRODUCTION: Postoperative reflux remains to be a challenge for patients with achalasia undergoing Heller myotomy. Similarly, per-oral endoscopic myotomy (POEM) is gaining rapid acceptance but the impossibility of adding a fundoplication is questioned as the main pitfall to control reflux. Electrical stimulation of the lower esophageal sphincter (LES) has emerged as a new alternative for the treatment of reflux disease. The objective of this study was to evaluate the potential benefits of combining electrical stimulation with endoscopic esophageal myotomy to prevent post procedural reflux. METHODS: Five pigs were subjected to POEM. After myotomy was completed, two electrical leads were implanted at the LES level and electrical stimulation was applied with the Endostim system with a regimen of 215 µs (5 mA amplitude), at 20 Hz for 25 min. LES pressures were recorded with manometry at pre and post-myotomy and after LES stimulation. RESULTS: Myotomy was completed successfully in all cases. Mean pre-myotomy LES pressure was 35.99 ± 8.08 mmHg. After myotomy, the LES pressure significantly dropped to 10.60 ± 3.24 mmHg (p = 0.03). Subsequent to LES-EST, LES pressure significantly increased to 21.74 ± 4.65 mmHg (p = 0.01). CONCLUSIONS: The findings of this study show that LES-EST in healthy animals increases LES pressure after POEM procedure, and could be useful tool to minimize gastroesophageal reflux.

In vivo assessment of a biological occluder for NOTES gastrotomy closure.

BACKGROUND: The objective of this study is to evaluate the closure of a transgastric natural orifice transluminal endoscopic surgery (NOTES) access using a multilayer extracellular matrix (ECM) occluder in a canine model. MATERIALS AND METHODS: Mongrel dogs (n = 4) underwent a transgastric NOTES peritoneoscopy and the gastrotomy was closed by deploying a 2-sided ECM occluder. Animals were killed at 7 days (n = 2) and 8 weeks (n = 2) for macroscopic and microscopic assessment. RESULTS: All procedures were completed without any complications. No air leaks were detected immediately after the procedure and at 48 hours postoperatively. At 7 days, ECM appeared to be resolved and mild mucosal inflammation was found at the site of gastrotomy. At 8 weeks, the gastrotomy site was macroscopically and microscopically covered with a normal-appearing gastric mucosa. There was an absence of inflammatory cells and no evidence of the ECM. CONCLUSION: The ECM occluder is safe and effective in this "proof-of-concept" preclinical model.