Gastroesophageal reflux disease (GERD) is a long-term digestive condition marked by the backflow of stomach contents into the esophagus [1]. The worldwide combined prevalence of GERD was found to be 13.98% [2]. GERD remains a significant public health problem due to its high global prevalence and potential for severe complications, including esophagitis, strictures, and progression to Barrett’s esophagus and esophageal adenocarcinoma. GERD commonly presents heartburn and regurgitation. Atypical symptoms can include chest pain, dental erosion, chronic cough, laryngitis, and asthma [1]. The three phenotypic presentations of GERD include erosive esophagitis (EE), characterized by visible mucosal breaks on endoscopy; non-erosive reflux disease (NERD), which presents with reflux symptoms but without visible mucosal injury; and Barrett’s esophagus, a condition marked by intestinal metaplasia of the esophageal lining that can predispose to esophageal adenocarcinoma [3]. Treatment options available for GERD range from over the counter (OTC) antacids to proton pump inhibitors (PPIs) and anti-reflux surgery [4]. Proton pump inhibitors (PPIs) are the most prescribed treatment for GERD, particularly for EE and NERD, because they provide strong and consistent acid suppression. However, despite their widespread use, systematic reviews have indicated that patients with NERD often have a less favorable response to PPIs compared to those with EE [5].

In cases where medical treatment for GERD is ineffective, fundoplication is utilized as a surgical option [6]. In this procedure, a surgeon constructs a sphincter—a muscle that tightens—at the lower end of the esophagus to prevent acid reflux. Long-term studies indicate that 90% of patients experience ongoing relief from heartburn and 80% from regurgitation after 10–20 years follow-up, and less than half of those with recurrent heartburn show signs of abnormal reflux [7]. Despite overall relief from reflux, dysphagia and bloating are the main reasons for patient dissatisfaction [8]. Therefore, both laparoscopic fundoplication procedures and prolonged use of PPIs have been questioned due to their possible associated side effects.

Magnetic sphincter augmentation (MSA) has emerged as an innovative surgical approach for treating GERD, employing the LINX device. The LINX device consists of a series of titanium beads, each with a magnetic core and connected by independent titanium wires, allowing for dynamic enhancement of the lower esophageal sphincter (LES) without compressing the esophagus [9]. This device improves the LES's ability to prevent acid reflux while still permitting natural belching and vomiting, which are important for postoperative comfort and avoiding issues like bloating. Compared to traditional fundoplication, this minimally invasive procedure offers several potential benefits, including reduced surgical trauma and fewer postoperative complications [10]. MSA is designed to be less invasive than laparoscopic fundoplication, as it avoids the extensive esophageal dissection and gastric fundus mobilization typically required in the latter [11]. Consequently, MSA may provide more predictable results with fewer complications and a faster recovery time [12,13].

Despite these advantages, there is limited comparative data on the long-term efficacy of MSA relative to Nissen fundoplication. Some studies suggest that MSA provides superior symptom control and quality of life improvements compared to fundoplication, but the evidence remains inconclusive [14]. Current literature highlights the need for more robust studies to directly compare these two surgical options and evaluate their relative benefits and risks comprehensively. Therefore, this systematic review and meta-analysis aim to provide a detailed comparison of MSA and laparoscopic fundoplication (LF) in terms of efficacy, safety, and patient outcomes to inform clinical decision-making and guide future research in the management of GERD.

Study design and protocol registration

This systematic review and meta-analysis adhered to the PRISMA guidelines in reporting. Prospectively, the protocol was registered with the PROSPERO international prospective register of systematic reviews under the identifier CRD42024564433. Ethical approval was not necessary in this study since it only dealt with publicly available data from previous observational cohort studies. All studies were conducted with adherence to the principles of the Helsinki Declaration.

Population selection and description

All studies included in our review had the following inclusion criteria:

• Observational cohort studies, either prospective or retrospective in nature.
• Written in the English language.
• Included patients who had been clinically diagnosed with GERD.
• Their initial postoperative outcomes were compared between MSA and LF. It provided data on rates of adverse events, postoperative complications, and the use of PPIs. PPI use was included as a criterion because postoperative PPI suspension is a key indicator of surgical effectiveness in GERD management, reflecting symptom control and reduction in medical therapy dependence.

Exclusion criteria encompassed abstracts, comments, reviews, or editorials. Other exclusion criteria included studies not comparing MSA and LF as well as those with incomplete clinical data or insufficient follow-up information. This was done to focus on the search for observational studies to better represent real world evidence of the comparative effectiveness and safety of MSA and LF. A total of 11 studies were included in the final analysis, which comprised a total of 2,156 patients. Data on demographic parameters like age, sex, and baseline clinical characteristics were noted from each study and include body mass index and presence of esophagitis. In each of these studies, the represented populations of GERD patients who underwent MSA or LF.

Collection of data and measurements

The reviewers extracted data independently regarding the characteristics of the study, author, year of publication, patient demographics (age, sex, body mass index [BMI]), clinical outcomes, and operative details: type of procedure performed, operative time, and length of stay. Postoperative dysphagia, GERD-HRQL scores, and PPI suspension rates comprised the major outcomes. Secondary outcomes consisted of the ability to vomit, the ability to belch, gas/bloat symptoms, and reoperation rates. Postoperative dysphagia was regarded as any swallowing difficulty requiring some form of intervention, including endoscopic dilation. GERD-HRQL scores were used to assess patient satisfaction and relief of symptoms with the surgery in relation to preoperative status. PPI suspension is a more robust secondary measure for evaluating outcomes, which confirms that surgical therapy indeed eliminated the symptoms of reflux. The other secondary outcome measures were the presence of gas/bloat symptoms and the ability to vomit and belch, which reflect retained digestive function.

Search strategy and information sources

We conducted a search of all electronic databases: PubMed, Embase, and Google Scholar up to June 30, 2024. The combined search terms for the query are:

('Magnetic Sphincter Augmentation' OR 'LINX Device') AND ('Fundoplication' OR 'Nissen Fundoplication' OR 'Toupet Fundoplication') AND ('Gastroesophageal Reflux Disease' OR 'GERD') AND ('outcomes' OR 'complications'). The objective of the search was to identify all relevant articles that compared the outcomes of MSA and LF in the treatment of GERD.

Statistical analysis

Review Manager (RevMan, version 5.4, The Cochrane Collaboration, Copenhagen, Denmark) was used for all statistical analyses.

Data synthesis included calculating pooled effect sizes using fixed- or random-effects models as appropriate based on heterogeneity. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for dichotomous data (dysphagia, gas/bloat symptoms, ability to vomit/belch, and reoperation rates). Mean differences (MDs) were calculated for continuous data (GERD-HRQL scores). The level of significance was set at p<0.05.

We also conducted meta-regression to analyze the effects of covariates on the pooled effect size. This approach sought to explain variability in observed effect sizes across studies and reduce residual heterogeneity. Visual inspection for publication bias was assessed by the asymmetry of funnel plots. When these were largely asymmetric, bias was considered potentially present. Possible subgroup analysis if feasible: Study design, patient features and outcome measures.

Study selection

Out of 1,421 articles initially retrieved, those not meeting the inclusion criteria based on title and abstract screening were excluded, leaving 32 articles. After reviewing the full texts, 11 articles were included in the final analysis. A total of 11 studies met the inclusion criteria and were included in the final analysis, comprising a total of 2,156 patients. Figure 1 illustrates the flowchart of the article screening process.

Characteristics of the included studies

The demographic, clinical, and operative characteristics of the patient cohort are detailed in Table 1. All surgeries were conducted using a laparoscopic approach. Most of the patients, totaling 1,332 (61.7%), underwent treatment with the LINX® (Thorax Medical) MSA device, whereas 824 (38.21%) underwent total (Nissen) or partial (Toupet) fundoplication. Patient ages ranged from 39.3 to 54 years, and the mean BMI ranged from 23.9 to 30. Hernia sizes were typically between 1 and 2 cm, except in one study by Richard, where sizes ranged from 3.2 to 5.7 cm. Operating room (OR) times varied across studies: MSA procedures ranged from 50.5 to 90.9 minutes, and LF procedures ranged from 63.7 to 131.8 minutes. Hospital stays post-surgery also varied: MSA patients typically stayed 13 to 48 hours, while LF patients had a broader range of 26.4 to 69.6 hours. Follow-up periods differed between MSA (6 to 48 months) and LF (7 to 42 months) groups. The DeMeester score, reflecting reflux severity, varied across studies: MSA scores ranged from 24.3 to 37.6, indicating moderate to severe reflux, while LF scores ranged from 5.1 to 56.3, indicating varying degrees of reflux severity managed by these interventions.

Outcomes

Postoperative GERD-HRQL

Using a random-effects model, the estimated pooled mean difference for postoperative GERD-HRQL among 1,320 patients is 0.03 (95% CI -0.97–1.03; p=0.101). There was observed heterogeneity among the studies (I²=59%, p=0.02), indicating variability in the results (Figure 2). The meta-regression analysis using Mean Age (estimate=2.3473, p=0.5361), Mean BMI (estimate=-1.3508, p=0.8233), and other covariates did not significantly reduce heterogeneity, as indicated by the non-significant p-value for the test of moderators (QM=0.8545, p=0.9310). Additionally, the model accounted for none of the observed heterogeneity (R²=0.00%), and none of the covariates were statistically significant predictors of the outcome.

Postoperative PPI suspension

Using a random-effects model, the estimated pooled OR for PPI suspension, derived from studies encompassing 1,098 patients, is 0.79 (95% CI 0.50–1.23; p=0.29). There is moderate heterogeneity observed (I²=51%, p=0.05), with τ²=0.19 (Figure 3). The meta-regression analysis using Mean Age (estimate=-0.1209, p=0.3284), Mean BMI (estimate=0.1819, p=0.7397), and Esophagitis (estimate=-0.0039, p=0.6190) as covariates did not significantly reduce heterogeneity, as indicated by the non-significant p-value for the test of moderators (QM=0.9647, p=0.8098). Additionally, the model accounted for none of the observed heterogeneity (R²=0%), and none of the covariates were statistically significant predictors of the outcome.

Ability to vomit

Employing a random-effects model, the estimated pooled OR for Ability to vomit, based on data from the studies involving 1,238 patients, is 11.40 (95% CI 7.67–16.95; p<0.00001). Moderate heterogeneity was noted (I²=49%, p=0.07) (Figure 4). The meta-regression analysis using Mean Age (estimate=-0.1202, p=0.2361), Mean BMI (estimate=0.2138, p=0.6061), and Esophagitis (estimate=-0.0038, p=0.5484) as covariates did not significantly reduce heterogeneity. This is indicated by the non-significant p-value for the test of moderators (QM=1.4256, p=0.6996). Additionally, the model accounted for none of the observed heterogeneity (R²=0%), suggesting that the covariates do not explain the variability in the effect sizes. None of the covariates were statistically significant predictors of the outcome.

Gas/Bloating

Using a random-effects model, the combined OR for symptoms of gas and bloating, based on data from the studies involving 1,318 patients, was estimated to be 0.45 (95% CI 0.28–0.72; p=0.001). There was moderate heterogeneity among the studies (I²=55%, p=0.04) (Figure 5). The meta-regression analysis incorporating Mean Age (estimate=-0.1202, p=0.2361), Mean BMI (estimate=0.2138, p=0.6061), and Esophagitis (estimate=-0.0038, p=0.5484) as covariates did not significantly reduce heterogeneity, as indicated by the non-significant p-value for the test of moderators (QM=1.4256, p=0.6996). Additionally, the model accounted for none of the observed heterogeneity (R²=0.00%), and none of the covariates were statistically significant predictors of the outcome.

Ability to belch

Using a random-effects model, the combined OR for the ability to belch, based on data from the studies involving 1,520 patients, was estimated to be 6.40 (95% CI 4.23–9.70; p<0.00001). There was no significant heterogeneity among the studies (I²=0%, p=0.44) (Figure 6). The meta-regression analysis incorporating Mean Age (estimate=0.0338, p=0.5167), and Mean BMI (estimate=-0.5379, p=0.4149) as covariates did not significantly reduce heterogeneity, as indicated by the non-significant p-value for the test of moderators (QM=0.9789, p=0.9130). Additionally, the model accounted for none of the observed heterogeneity (R²=0.00%), and none of the covariates were statistically significant predictors of the outcome.

Dysphagia

Using a random-effects model, the combined OR for the dysphagia, based on data from the studies involving 922 patients, was estimated to be 1.42 (95% CI 0.64–3.18; p=0.39). There was no significant heterogeneity among the studies (I²=80%, p=0.0001) (Supplemental Figure 1). The meta-regression analysis incorporating Mean Age (estimate=0.0338, p=0.5167), and Mean BMI (estimate=-0.5379, p=0.4149) as covariates did not significantly reduce heterogeneity, as evidenced by the non-significant p-value for the test of moderators (QM=0.9789, p=0.9130). Additionally, the model accounted for none of the observed heterogeneity (R²=0.00%), and none of the covariates were statistically significant predictors of the outcome. The residual heterogeneity was negligible (I²=0.00%, p=0.4777), suggesting that the included covariates did not explain variability beyond that accounted for by random effects alone.

Postoperative endoscopic dilation

Considering random effect model, the estimated pooled OR of endoscopic dilation, resulting from the studies, which include a total of 811 patients, is 2.03 (95% CI 1.19–3.47; p=0.010). The heterogeneity is not significant (I²=44%; p=0.10) (Supplemental Figure 2). There was no significant residual heterogeneity among the studies (I²=0%, p=0.4777), indicating that the variability in the effect sizes across studies was minimal after accounting for the covariates. The meta-regression analysis incorporating Mean Age (estimate=0.0338, p=0.5167), Mean BMI (estimate=-0.5379, p=0.4149), and Esophagitis (estimate = not included in the results) as covariates did not significantly reduce heterogeneity, as evidenced by the non-significant p-value for the test of moderators (QM=0.9789, p=0.9130). Additionally, the model accounted for none of the observed heterogeneity (R²=0.00%), and none of the covariates were statistically significant predictors of the outcome.

Reoperation

Considering random effect model, the estimated pooled OR of reoperation, resulting from the studies, which include a total of 1,753 patients, is 1.32 (95% CI 0.83–2.09; p=0.183). The heterogeneity is negligible (I²=0.0%; p=0.44) (Supplemental Figure 3). The meta-regression analysis using Mean Age (estimate=0.1912, p=0.1131), Mean BMI (estimate=0.2231, p=0.6372), and Esophagitis (estimate=0.0028, p=0.6668) as covariates did not significantly reduce heterogeneity, as indicated by the non-significant p-value for the test of moderators (QM=5.6929, p=0.1275). Additionally, the model accounted for all observed heterogeneity (R²=100%), but none of the covariates were statistically significant predictors of the outcome.

Quality assessment

The quality assessment using the Newcastle-Ottawa Scale (NOS) revealed that most studies were of good quality, with scores ranging from 6 to 8. Out of the 11 studies evaluated, 8 studies were rated as good quality (score ≥7), while 3 studies were rated as moderate quality (score ≥5 to <7). No studies were rated as poor quality, indicating that the risk of bias across the studies is relatively low (Supplemental Table 1).

Sensitivity analysis

The meta-regression analysis was conducted as part of the sensitivity analysis to explore potential sources of heterogeneity among the studies. Despite including covariates such as Mean Age, Mean BMI, and Esophagitis, the meta-regression did not significantly reduce heterogeneity across outcomes. None of the covariates were statistically significant predictors of the outcomes, and the models accounted for none of the observed heterogeneity (R²=0%). This suggests that the variability in effect sizes is likely due to other unmeasured factors or random variation.

Publication bias

The funnel plot generated through RevMan appeared symmetrical, suggesting no significant publication bias among the included studies. This indicates that the likelihood of publication bias impacting the results of this meta-analysis is low.

This systematic review and meta-analysis compared the short-term outcomes of MSA and LF in GERD management. Both procedures demonstrated efficacy in improving patient symptoms and quality of life.

The pooled analysis showed no significant difference in postoperative GERD-HRQL scores between MSA and LF, indicating similar improvements in patient-reported quality of life. Moderate heterogeneity (I²=59%) was observed [17]. Meta-regression incorporating age, BMI, and esophagitis did not explain this variability, as none of these covariates were significant predictors. This suggests that unmeasured factors, such as surgical expertise or postoperative care, may contribute. Clinically, both procedures appear equally effective in alleviating reflux-related quality-of-life impairments.

Rates of PPI suspension did not differ significantly between MSA and LF, although the pooled OR slightly favored LF. Heterogeneity was moderate (I²=51%). Meta-regression again failed to identify significant predictors, indicating that variability likely stems from differences in patient selection or reporting criteria across studies. The comparable rates reinforce that both procedures substantially reduce dependence on PPIs, an important indicator of treatment success. MSA showed a clear advantage in preserving the ability to vomit, with a markedly higher pooled OR. Moderate heterogeneity was observed (I²=49%), but meta-regression did not reveal age, BMI, or esophagitis as significant moderators. This consistency across subgroups underscores MSA’s clinical relevance in maintaining physiological gastric venting [14].

Patients undergoing MSA experienced significantly fewer gas/bloat symptoms than those treated with LF [14]. Moderate heterogeneity was present (I²=55%), but meta-regression failed to identify age, BMI, or esophagitis as explanatory variables. This finding aligns with the functional advantage of MSA in preserving belching and vomiting and highlights a meaningful improvement in postoperative comfort. The ability to belch was consistently superior in MSA, with no significant heterogeneity Meta-regression confirmed that none of the examined covariates (age, BMI) influenced the outcome [14]. This robust result emphasizes MSA’s reproducible functional benefits across diverse populations.

Dysphagia rates were comparable between MSA and LF, with no statistically significant difference. However, the ability to address and potentially reverse the MSA device without significant surgical intervention offers a unique advantage for patient management [9]. High heterogeneity was noted (I²=80%), and meta-regression using age and BMI did not explain the variability. Clinically, this suggests that dysphagia remains a potential complication of both procedures, regardless of surgical approach [10]. Importantly, however, MSA allows device removal or endoscopic dilation as management options, offering flexibility that LF lacks.

The pooled analysis demonstrated higher rates of endoscopic dilation in MSA compared with LF. Heterogeneity was moderate (I²=44%), but meta-regression indicated that neither age nor BMI were significant contributors. This finding underscores the importance of tailored follow-up care and dietary guidance after MSA, as postoperative dysphagia may require early intervention. Reoperation rates were similar between the two groups, with negligible heterogeneity. Although the OR for reoperation was not statistically significant, there was a trend indicating a lower risk of redo surgery with MSA compared to LF (OR: 0.77) [11,15]. Meta-regression indicated no significant predictors, and the model accounted for all heterogeneity. This reinforces the durability and procedural stability of both MSA and LF in the short term.

Despite multiple meta-regression analyses, heterogeneity observed in outcomes such as GERD-HRQL, PPI suspension, vomiting, and bloating could not be explained by common covariates. Other factors, such as variability in surgical technique, perioperative care, and anatomical differences, likely contribute. These findings highlight the influence of diverse clinical practices in shaping postoperative results [16]. A limitation of this study is the relative scarcity of head-to-head comparative trials between MSA and LF. While several cohort studies have reported promising results for MSA, long-term randomized controlled trials remain limited. This restricts the ability to perform deeper comparative analyses with established literature and underscores the need for future studies.

This review adhered to PRISMA guidelines and was prospectively registered in PROSPERO. Strengths include a large, pooled sample size, reliance on real-world observational data, and the use of meta-regression to investigate heterogeneity. Limitations include the lack of randomized controlled trials, variations in follow-up duration, heterogeneity in reporting of outcome measures, and residual confounding. Furthermore, the number of studies per outcome varied, reducing the statistical power for some analyses.

Both MSA and LF provide effective symptom relief and quality-of-life improvements in GERD patients. MSA offers distinct short-term advantages, particularly in preserving the ability to vomit and belch and reducing gas-bloat symptoms. However, LF remains the established gold standard, supported by decades of evidence demonstrating its long-term durability and efficacy. MSA represents a promising, less invasive alternative, but further high-quality randomized controlled trials are needed to determine whether its short-term benefits translate into comparable long-term outcomes.

GERD: Gastroesophageal Reflux Disease; MSA: Magnetic Sphincter Augmentation; LF: Laparoscopic Fundoplication; PPI: Proton Pump Inhibitor; HRQL: Health-Related Quality of Life; OR: Odds Ratio; CI: Confidence Interval; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PROSPERO: International Prospective Register of Systematic Reviews; LES: Lower Esophageal Sphincter; BMI: Body Mass Index; NOS: Newcastle-Ottawa Scale

The authors declare that there are no competing interests or conflicts of interest related to this study.

Not applicable.

The author wishes to express gratitude to the Deanship of Scientific Research at Shaqra University for their financial support through the Research Support Program, under the code SU-Abc-xxxx.