Measurement of outflow resistance imposed by magnetic sphincter augmentation: defining normal values and clinical implication

Ineffective esophageal motility: The impact of change of criteria in Chicago Classification version 4.0 on predicting outcome after magnetic sphincter augmentation

BACKGROUND

The most recent update of the Chicago Classification (CCv4.0) attempts to provide a more clinically relevant definition for ineffective esophageal motility (IEM). The impact of this new definition on predicting outcome after antireflux surgery is unknown. The aim of this study was to compare utility of IEM diagnosis based on CCv4.0 to CCv3.0 in predicting surgical outcome after magnetic sphincter augmentation (MSA) and to assess any additional parameters that hold value in future definitions.

METHODS

Records of 336 patients who underwent MSA at our institution between 2013 and 2020 were reviewed. Preoperative manometry files were re-analyzed using both Chicago Classification version 3.0 (CCv3.0) and CCv4.0 definitions of IEM. The utility of each IEM definition in predicting surgical outcome was then compared. Individual manometric components and impedance data were also assessed.

KEY RESULTS

Immediate dysphagia was reported by 186 (55.4%) and persistent dysphagia by 42 (12.5%) patients. CCv3.0 IEM criteria were met by 37 (11%) and CCv4.0 IEM by 18 (5.4%) patients (p = 0.011). CCv3.0 and CCv4.0 IEM were equally poor predictors of immediate (AUC = 0.503 vs. 0.512, p = 0.7482) and persistent (AUC = 0.519 vs. 0.510, p = 0.7544) dysphagia. The predicted dysphagia probability of less than 70% bolus clearance (BC) was 17.4%, higher than CCv4.0 IEM at 16.7%. When BC was incorporated into CCv4.0 IEM criteria, the probability increased significantly to 30.0% (p = 0.0042).

CONCLUSIONS & INFERENCES

The CCv3.0 and CCv4.0 of IEM are poor predictors of dysphagia after MSA. Adding BC to the new definition improves its predictive utility and should be considered in future definitions.

Magnetic sphincter augmentation and high-resolution manometry: impact of biomechanical properties on esophageal motility and clinical significance for selection and outcomes

Magnetic sphincter augmentation (MSA)was introduced as an alternative to laparoscopic Nissen fundoplication (LNF). This reproducible, outpatient procedure addresses the etiology of gastroesophageal reflux disease by implanting a ring of magnetic beads across the esophagogastric junction (EGJ). MSA is designed to resist effacement of the lower esophageal sphincter (LES) and, similar to LNF, results in restoration of anti-reflux barrier competency by increasing overall length, intraabdominal length and resting pressure of the sphincter. However, the novel use of magnets to augment the physiology of the LES poses unique challenges to the physiology of the EGJ and esophagus. These impacts are best revealed through manometry. The degree of restrictive forces at the EGJ, as measured by intrabolus pressure and integrated relaxation pressure, is higher after MSA compared with LNF. In addition, contrary to the LNF, which retains neurohormonal relaxation capability during deglutition, the magnetic forces remain constant until forcibly opened. Therefore, the burden of overcoming EJG resistance is placed solely on the esophageal body contractile force, as measured by distal contractile integral and distal esophageal amplitude. The main utility of preoperative manometry is in determining whether a patient's esophagus has sufficient contractility or peristaltic reserve to adapt to the challenge of an MSA. Manometric thresholds predictive of MSA outcomes deviate from those used to define named Chicago Classification motility disorders. Therefore, individual preoperative manometric characteristics should be analyzed to aid in risk stratification and patient selection prior to MSA.

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.

The role of magnetic sphincter augmentation (MSA) in the gastroesophageal reflux disease (GERD) treatment pathway: the gastroenterology perspective

Magnetic sphincter augmentation (MSA) is a surgical intervention for well-characterized gastroesophageal reflux disease (GERD), where the esophagogastric junction barrier is augmented using a bracelet of magnetized titanium beads. MSA could be an attractive option for patients with documented GERD who wish to avoid long-term pharmacologic therapy or whose symptoms are not adequately managed with lifestyle modifications and pharmacologic therapy. The 'ideal' MSA patient is one with prominent regurgitation, without dysphagia or esophageal motor dysfunction, with objective evidence of GERD on upper endoscopy and/or ambulatory reflux monitoring. Appropriate candidates with significant hiatus hernia may pursue MSA with concomitant hiatus hernia repair. The increasing adoption of MSA in the GERD treatment pathway reflects research that shows benefits in long-term outcomes and healthcare costs compared with other established therapies in appropriate clinical settings.

Impact of Objective Colonic and Whole Gut Motility Data as Measured by Wireless Motility Capsule on Outcomes of Antireflux Surgery

BACKGROUND

Studies show higher rates of dissatisfaction with antireflux surgery (ARS) outcomes in patients with chronic constipation. This suggests a relationship between colonic dysmotility and suboptimal surgical outcome. However, due to limitations in technology, there is no objective data available examining this relationship. The wireless motility capsule (WMC) is a novel technology consisting of an ingestible capsule equipped with pH, temperature, and pressure sensors, which provide information regarding regional and whole gut transit times, pH and motility. The aim of this study was to assess the impact of objective regional and whole gut motility data on the outcomes of ARS.

STUDY DESIGN

This was a retrospective review of patients who underwent WMC testing before ARS. Transit times, motility, and pH data obtained from different gastrointestinal tract regions were used in analysis to determine factors that impact surgical outcome. A favorable outcome was defined as complete resolution of the predominant reflux symptom and freedom from antisecretory medications.

RESULTS

The final study population consisted of 48 patients (fundoplication [n = 29] and magnetic sphincter augmentation [n = 19]). Of those patients, 87.5% were females and the mean age ± SD was 51.8 ± 14.5 years. At follow-up (mean ± SD, 16.8 ± 13.2 months), 87.5% of all patients achieved favorable outcomes. Patients with unfavorable outcomes had longer mean whole gut transit times (92.0 hours vs 55.7 hours; p = 0.024) and colonic transit times (78.6 hours vs 47.3 hours; p = 0.028), higher mean peak colonic pH (8.8 vs 8.15; p = 0.009), and higher mean antral motility indexes (310 vs 90.1; p = 0.050).

CONCLUSIONS

This is the first study to demonstrate that objective colonic dysmotility leads to suboptimal outcomes after ARS. WMC testing can assist with preoperative risk assessment and counseling for patients seeking ARS.

Removal of the magnetic sphincter augmentation device: an assessment of etiology, clinical presentation, and management

BACKGROUND

Magnetic sphincter augmentation (MSA) erosion, disruption or displacement clearly requires device removal. However, up to 5.5% of patients without anatomical failure require removal for dysphagia or recurrent GERD symptoms. Studies characterizing these patients or their management are limited. We aimed to characterize these patients, compare their outcomes, and determine the necessity for further reflux surgery.

METHODS

This is a retrospective review of 777 patients who underwent MSA at our institution between 2013 and 2021. Patients who underwent device removal for persistent dysphagia or recurrent GERD symptoms were included. Demographic, clinical, objective testing, and quality of life data obtained preoperatively, after implantation and following removal were compared between removal for dysphagia and GERD groups. Sub-analyses were performed comparing outcomes with and without an anti-reflux surgery (ARS) at the time of removal.

RESULTS

A total of 40 (5.1%) patients underwent device removal, 31 (77.5%) for dysphagia and 9 (22.5%) for GERD. After implantation, dysphagia patients had less heartburn (12.9-vs-77.7%, p = 0.0005) less regurgitation (16.1-vs-55.5%, p = 0.0286), and more pH-normalization (91.7-vs-33.3%, p = 0.0158). Removal without ARS was performed in 5 (55.6%) GERD and 22 (71.0%) dysphagia patients. Removal for dysphagia patients had more complete symptom resolution (63.6-vs-0.0%, p = 0.0159), freedom from PPIs (81.8-vs-0.0%, p = 0.0016) and pH-normalization (77.8-vs-0.0%, p = 0.0455). Patients who underwent removal for dysphagia had comparable symptom resolution (p = 0.6770, freedom from PPI (p = 0.3841) and pH-normalization (p = 0.2534) with or without ARS. Those who refused ARS with removal for GERD had more heartburn (100.0%-vs-25.0%, p = 0.0476), regurgitation (80.0%-vs-0.0%, p = 0.0476) and PPI use (75.0%-vs-0.0%, p = 0.0476).

CONCLUSIONS

MSA removal outcomes are dependent on the indication for removal. Removal for dysphagia yields excellent outcomes regardless of anti-reflux surgery. Patients with persistent GERD had worse outcomes on all measures without ARS. We propose a tailored approach to MSA removal-based indication for removal.

Real-world evidence with magnetic sphincter augmentation for gastroesophageal reflux disease: a scoping review

Background

The burden of gastroesophageal reflux disease (GERD) is high, with up to 30% of the Western population reporting reflux-related symptoms with or without hiatal hernia. Magnetic sphincter augmentation (MSA) is a standardized laparoscopic procedure for patients who are dissatisfied with medical therapy and for those with early-stage disease who would not usually be considered ideal candidates for fundoplication. The MSA device is manufactured in different sizes and is designed to augment the physiologic barrier to reflux by magnetic force.

Methods

An extensive scoping review was performed to provide a map of current evidence with respect to MSA, to identify gaps in knowledge, and to make recommendations for future research. All the authors contributed to the literature search in PubMed and Web of Science and contributed to summarizing the evidence.

Results

Magnetic sphincter augmentation, especially in combination with crural repair, is effective in reducing GERD symptoms, proton pump inhibitor use, and esophageal acid exposure, and in improving patients’ quality of life. Safety issues such as device erosion or migration have been rare and not associated with mortality. The MSA device can be removed laparoscopically if necessary, thereby preserving the option of fundoplication or other therapies in the future. Contraindication to scanning in high-power Tesla magnetic resonance systems remains a potential limitation of the MSA procedure. High-resolution manometry and functional lumen imaging probes appear to be promising tools to predict procedural outcomes by improving reflux control and reducing the incidence of dysphagia.

Conclusion

A consensus on acquisition and interpretation of high-resolution manometry and impedance planimetry data is needed to gain better understanding of physiology, to improve patient selection, and to pave the way for a personalized surgical approach in antireflux surgery.

Reference high-resolution manometry values after magnetic sphincter augmentation

BACKGROUND

Magnetic sphincter augmentation (MSA) is an innovative antireflux procedure that can improve lower esophageal sphincter (LES) competency and reduce symptoms of gastroesophageal reflux disease (GERD). Some patients report postoperative dysphagia. To date, no studies have described reference high-resolution manometry (HRM) values after MSA implantation.

METHODS

High-resolution manometry was performed in patients free of dysphagia after MSA with or without concurrent crura repair. Reference values for all parameters of the Chicago Classification were defined as those between the 5th and 95th percentiles. The contribution of concurrent crura repair to LES competency and to reference values was also analyzed.

KEY RESULTS

Eighty-four patients met the study inclusion criteria. The upper limit of normality for integrated relaxation pressure (IRP) and intrabolus pressure (IBP) was 20.2 mmHg and 30.3 mmHg, respectively. Both variables were higher after MSA compared to normative Chicago Classification v3.0 values. The Distal Contractile Integral upper limit was in the range of normality. Patients undergoing crura repair had a significantly higher IRP (p = 0.0378) and lower GERDQ-A scores (p = 0.0374) and Reflux Symptom Index (p = 0.0030) compared to those who underwent MSA device implantation alone.

CONCLUSION & INFERENCES

This study provides HRM reference values for patients undergoing successful MSA implantation. Crural repair appears to be a key component of LES augmentation and is associated with improved clinical outcomes.

The role of magnetic sphincter augmentation in the treatment of gastroesophageal reflux disease

PURPOSE OF REVIEW

Magnetic sphincter augmentation (MSA) has been designed as a less disruptive and more standardized laparoscopic surgical procedure than fundoplication for patients with early stage gastroesophageal reflux disease (GERD). We analyzed the more recent literature in search of updates regarding indications, technique, perioperative management, and long-term outcomes.

RECENT FINDINGS

Over the years, the procedure of MSA has evolved to including full hiatus repair rather than relying on the preservation of the phreno-esophageal ligament. Restoring the mechanical synergy between the lower esophageal sphincter and the crural diaphragm has the potential to further enhance the antireflux barrier. The adoption of this approach has led to expand the indications from early stage disease to different scenarios including patients with high esophageal acid exposure, atypical symptoms, large hiatal hernias, Barrett's esophagus, postbariatric surgery, and previously failed fundoplication.

SUMMARY

MSA has a favorable side-effect profile and is highly effective in reducing typical reflux symptoms, medication dependency, and esophageal acid exposure. Excellent outcomes have been confirmed over a 12-year follow-up, indicating that the operation has the potential to prevent GERD progression. Further studies are needed to confirm the cost-effectiveness of this procedure in patients with more advanced disease-stage and prior gastric surgery. A randomized control trial comparing MSA with fundoplication could raise the level of evidence and the strength of recommendation.

Swallow-induced syncope after magnetic sphincter augmentation: a case report and physiologic explanation

Swallow-induced syncope is a rare cause of syncope that occurs during or immediately after swallowing. This phenomenon has been reported in association with few esophageal pathologies and the likely explanation is a vagal reflex during deglutition that results in inhibition of the cardiac conduction system. This report describes a case of swallow-induced syncope related to the implantation of a magnetic sphincter augmenting (MSA) device. Two episodes of syncope after food bolus occurred with the device in place and upon removal of the device, the patient had no further episodes of syncope. Vagal stimulation from distention of the esophagus or vagus nerve contact irritation by the implant are the potential explanation for syncope in this patient. Although this is an extremely rare complication of magnetic sphincter device augmentation, it is one that physicians should be cognizant of given the dangers of syncope events.

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.