A comparative study of magnetic sphincter augmentation and Nissen fundoplication in the management of GERD
- Open Access
- 14.10.2024
- Original Article
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Abstract
Introduction
Gastroesophageal reflux disease (GERD) is a prevalent disease that is found throughout the world. In 2017, the worldwide occurrence was around 9,283 (8,189–10,400) cases per 100,000 individuals [1]. GERD presents with both esophageal (acid reflux, heartburn) and extra-esophageal (throat discomfort, coughing, and chest pain) symptoms. Proton pump inhibitors (PPIs) efficiently alleviate symptoms by minimizing excessive acid exposure, anxiety, and depression associated with the disease. However, the long-term risks associated with drugs and the use of PPIs can have a significant influence on patients’ quality of life [2].
Surgical intervention serves as a radical non-pharmacological cure for GERD at the anatomical level. Fundoplication has become the mainstream method for controlling reflux by repairing hiatal hernias. Laparoscopic Nissen fundoplication (LNF) is a highly effective surgical technique for long-term GERD management [3]. Magnetic sphincter augmentation (MSA), which received FDA approval in 2012 [4], utilizes the LINX system to enhance lower esophageal sphincter (LES) pressure, achieving an anti-reflux effect. The magnet within the magnetic ring aids in maintaining the closure of the LES, preventing the reflux of acid from the stomach into the esophagus; while consuming food or water, swallowing exerts a force that can lead to the separation of the magnet, causing the magnetic ring device to expand. As a result, the LES opens up, allowing the passage of food or liquid into the stomach. Multiple clinical facilities worldwide are currently conducting ongoing clinical trials on this technology. Initial data suggests that MSA helps determine long-term management of aberrant acid exposure and symptoms of GERD [5], with therapeutic efficacy and safety comparable to Nissen fundoplication [6, 7]. The latest guidelines of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) recommended MSA as a surgical option for anti-reflux treatment [8].
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While research studies have compared MSA with fundoplication, further research is needed to enhance these conclusions [9]. Given the increasing data, our institution conducted a retrospective study to directly assess the safety and effectiveness of MSA and LNF in treating GERD. This study involved a contemporaneous, case-matched series of patients, emphasizing enhancing the quality of life for those who underwent surgical procedures. This study also aims to provide insights into the perioperative management and surgical procedural steps for MSA.
Methods
This work complies with STROBE reporting criteria. The Medical Ethics Committee has evaluated this study, and informed consent was acquired. This is a Pre-market clinical study on MSA which was produced by Ningbo Senscure Biotechnology Co., Ltd., (Approval No: 2018QX018), and patients who met the matching criteria for LNF in 2022 were included as the control group (ethic number: KY2024093). Patients with incomplete examination and follow-up data were excluded.
This retrospective analysis did not include patients with a history of stomach or esophageal cancer, cholecystectomy, anti-reflux surgery, or gastroesophageal surgery. Gastroscopy, high-resolution manometry (HRM), and contrast-enhanced ultrasonography are examples of preoperative tests. Preoperative questionnaire surveys were administered using the GERD-Q scale. According to the rule of the clinical trial, patients undergoing MSA were required to undergo a 24-hour pH test before and after the surgery. They were required to undergo chest X-ray and gastroscopy examination again one year after surgery. Patients who have a history of dysphagia or esophageal motility abnormalities, a gastroscopy showing a hiatal hernia larger than 2 cm, grade C and D reflux esophagitis, or who will require an MRI examination in the future will not be eligible for MSA.
Statistical analysis
The SPSS 25.0 software was used for statistical analysis. The statistical data were expressed as median (P25, P75) and mean ± standard deviation. Pearson’s chi-squared test, paired sample t-tests, and the Wilcoxon signed-rank test were used to compare the statistical differences in the data. P-values less than 0.05 were regarded as statistically significant.
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Results
Demographic information and baseline
A total of 40 eligible patients were included in this study, including 16 MSA cases and 24 LNF cases. Their demographic data are presented in Table 1. The age, gender, Body mass index (BMI), duration of GERD symptoms, GERD-Q score, distal contraction integral (DCI), and LES resting pressure of the two groups of patients are well-matched. Contrast-enhanced ultrasound effectively identifies gastroesophageal reflux in most patients, but gastroscopy has limited success in detecting esophagitis and hiatal hernia.
Table 1
Patient demographic information and baseline
Baseline information | MSA | LNF | P value |
|---|---|---|---|
Age (year) | 40.19 ± 9.40 | 46.88 ± 16.83 | 0.12 |
Gender (% male) | 50 | 62.5 | |
BMI | 21.54 ± 3.59 | 22.33 ± 3.67 | 0.50 |
Duration of GERD symptoms (year) | 2(1,3.75) | 2.5(1,6.75) | 0.44 |
Gerd-Q | 10.50 ± 3.18 | 10.50 ± 1.77 | 0.99 |
HRM | |||
DCI (lying down) | 1026.5(764.25,1471) | 596(522.75,1419.5) | 0.05 |
LES resting pressure | 20.39 ± 9.22 | 23.36 ± 11.09 | 0.38 |
Gastroscope | |||
Gastritis | 100% | 91.67% | |
Reflux esophagitis LA-A/LA-B | 12.50% | 20.83% | |
Hiatal hernia | 50% | 50% | |
Contrast-enhanced ultrasound | |||
Reflux | 81.25% | 91.67% | |
Hiatal hernia | 18.75% | 37.5% | |
Surgical information
An experienced surgical team led by a single surgeon (Dr. Zhifei Wang) performed all the surgeries. All procedures were performed laparoscopically.
The adhesions connecting the left liver to the operational area were detached, and the small omentum sac was opened. The hepatic branch of the vagus nerve was conserved. The right crus of the diaphragm was initially uncovered. From bottom to top and from right to left, the tissue surrounding the esophagus was freed up to the angle of His. At the interface of the red and white tissues, adhesion was separated between the right crus of the diaphragm and the hernial sac. The confluence of the left and right crura behind the esophagus was then exposed. The vagus nerve was revealed and protected by elevating the esophagus, and the posterior esophageal tissue was freed by dissecting closely along the left crus of the diaphragm. A posterior esophageal tunnel was created to facilitate esophageal retraction by threading a size 8 red urinary catheter through this tunnel.
The phrenoesophageal ligament was opened by the surgeon, who also removed the adhesions that were present between the hernial sac and the left crus of the diaphragm. With great care, the pleura was preserved when the abdominal section of the esophagus was circumferentially released up to 5 cm above the diaphragm. The hiatus was then closed using 2 − 0 non-absorbable sutures, leaving only enough space for the esophagus to pass through (Fig. 1a-b).
The esophageal circumference was measured using an esophageal sizing device to determine an appropriate size for the selected MSA device. The sizing device mainly consists of a size indicator, a shaft, and a sizing loop (Fig. 2a). The surgeon passes the handle through the posterior of the esophagus and pushes out the sizing loop, pushing the holder. When the end of the sizing loop with a magnet is combined with the end of the shaft, the holder is pulled back to wrap the sizing loop around the esophagus tightly. There is a scale indicator on the shaft(Fig. 2b), and the surgeon selects the corresponding MSA device based on the indicated value (Fig. 1c-d). No mesh or esophageal bougie was used during the surgery and MSA device placement. For LNF, an absorbable mesh was placed and fixed by sutures. A 360° floppy fundoplication was fashioned over a 44 F bougie using three pledged Ethibond sutures, with the second and third sutures incorporating an esophageal wall.
Fig. 1
Surgical procedures. a: Exposure of the hiatal hernia. b: Repair of the hiatal hernia. c: Measurement of the esophageal circumference. d: Placement of the MSA device
Fig. 2
The sizing device
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The duration of the MSA operation was 112 (105,120.75) minutes, significantly shorter than the 175 (160,205) minutes needed for LNF. The incidence of hiatal hernia and the duration of postoperative hospitalization were comparable across the two surgical techniques (Table 2).
Table 2
Surgery information
Surgical information | MSA | LNF | P value |
|---|---|---|---|
Operation duration (min) | 112 (105,120.75) | 175 (160,205) | < 0.001 |
Hiatal hernia (cm) | 1.5 (1.0,2.0) | 2 0.0(1.0,2.0) | 0.12 |
Size for placing the MSA device | |||
13 | 12.5% | ||
14 | 43.75% | ||
15 | 31.25% | ||
16 | 12.5% | ||
Postoperative hospital stay (days) | 3(3,4) | 3(3,4) | 0.70 |
Follow-up after surgery
The GERD-Q questionnaire scores of MSA and LNF patients were lower one year later than before surgery, yet there was no statistically significant difference between them. The 24-hour pH test showed a significant improvement in abnormal acid exposure for the patients who underwent MSA surgery. (Table 3).
Table 3
Changes of Gerd-Q and 24-hour pH test in MSA
Preoperative | Postoperative | P-value | |
|---|---|---|---|
Gerd-Q | |||
MSA | 10.50 ± 3.18 | 6(6,8.5) | 0.002 |
LNF | 10.50 ± 1.77 | 6(5,7.5) | < 0.001 |
P-value | 0.99 | 0.34 | |
24-h pH test in MSA | |||
Demeester score | 52.55(31.73,78.57) | 2.1(0.8,8.85) | 0.001 |
Abnormal acid exposure (%) | 13.9(9.08,24.95) | 0.55(0.075,3.58) | 0.001 |
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Following surgery, MSA patients could return to a regular diet sooner than LNF patients [1(0.5,1.5) vs. 3(1.63,5.38) month(s), p < 0.001]. MSA patients may require less time than LNF patients to resume eating after surgery (5(0,10) vs. 10(5,15) min, p = 0.09). There were no significant differences in weight loss, daily strength recovery, dysphagia, or upper abdominal discomfort between MSA and LNF patients. Patients with MSA have improved hiccup ability (87.5% vs. 45.83%, P = 0.01). (Table 4)
All MSA patients underwent gastroscopy and chest X-ray examination, and no gastrointestinal perforation or damage to the esophageal and gastric mucosa was found.
Four patients displayed symptoms of anxiety, with two patients in the MSA group and two patients in the LNF group. Approximately 50% of the patients encountered different levels of dysphagia. However, none of them underwent endoscopic dilatation. One patient with MSA underwent a second surgical procedure at a different facility to remove the MSA device because of chest pain. However, the chest pain did not improve after removing the device.
Table 4
1-year follow-up
Follow-up | MSA | Nissen Fundoplication | P value |
|---|---|---|---|
Recovery of normal eating (month) | 1(0.5,1.5) | 3(1.63,5.38) | < 0.001 |
More time spent on normal eating (min) | 5(0,10) | 10(5,15) | 0.09 |
Weight loss (kg) | 0(0,0) | 0(0,1.5) | 0.21 |
Recovery of daily strength (month) | 1(1,1.88) | 1.5(1,2.5) | 0.14 |
Any dysphagia (%) | 43.75 | 54.17 | 0.52 |
Ability of hiccup (%) | 87.5 | 45.83 | 0.01 |
Upper abdominal discomfort (%) | 43.75 | 37.5 | 0.69 |
Anxiety (case) | 2 | 2 | |
Redo surgery (case) | 1 | 0 |
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Discussion
Patients having MSA and LNF operations were compared in this study. Every patient experiencing GERD had required preoperative assessments to guarantee they met the surgery criteria. Unlike MSA patients, those undergoing LNF were not required to have a 24-hour pH test. Their diagnosis was primarily based on symptoms, PPI response, and endoscopy [10]. Additionally, we utilized ultrasonographic gastrography to diagnose GERD, as it allows for the observation of contrast agent reflux from the stomach into the esophagus [11]. MSA surgery demonstrated significantly shorter operative times. MSA and LNF showed reasonable short-term control of GERD symptoms, as reflected in comparing the GERD-Q scale before and after the surgery. At the same time, the 24-hour pH test performed again after MSA patients confirmed the effectiveness of this surgery in controlling acid exposure. Similar to LNF, individuals who underwent MSA surgery reported increased postoperative throat phlegm and adhered to a liquid diet. Patients reported higher levels of flatulence and faster satiety during routine follow-ups than before surgery but no discernible weight loss linked to dietary changes. These results imply that MSA may speed up the restoration of regular eating patterns.
There were no cases of severe intraoperative bleeding or esophageal or stomach injury brought on by the implantation of an MSA device. Furthermore, gastroscopic and chest X-ray tests at the one-year follow-up showed no corrosion related to the MSA device, indicating excellent intraoperative and short-term postoperative MSA safety. One patient complained of “chest pain” and requested reoperation to remove the MSA device. However, a second surgery did not significantly improve the patient’s “chest pain”, and the patient refused psychological intervention. Two patients experienced postoperative anxiety and had minor reflux indicative of poor MSA efficacy. These three cases highlight the significance of psychological factors in GERD onset and treatment [12]. Symptom-related long-term discomfort can lead to emotional changes. Postoperative reflux symptom recurrence may amplify these emotions, leading to patient dissatisfaction with the surgical outcome despite controlling these symptoms with medication [13]. Our experience demonstrates that improved postoperative patient education in the outpatient clinic successfully meets patients’ expectations. With the patient’s permission, preserving surgical footage and recording photographs can help reduce postoperative discomfort and anxiety.
Comparative studies between MSA and LNF by numerous international researchers indicate that MSA exhibits a safety and efficacy profile comparable to that of Nissen fundoplication. MSA also outperforms Nissen fundoplication in reducing symptoms such as belching, vomiting, and bloating [14‐17]. On the other hand, MSA shows superior outcomes compared to TIF in terms of postoperative discontinuation of PPIs [18], better management of postoperative reflux, and higher overall patient satisfaction [19, 20]. The preoperative preparation for MSA is comparable to that of fundoplication. MSA surgery can be completed more quickly than LNF due to reduced procedural stages. This includes less mobilization of the gastric fundus, eliminating time-consuming changes, and the fixation of the wrap. In terms of economic burden, some studies suggest that the short-term cost of MSA surgery is higher than that of LNF. However, in the long run, MSA costs are relatively low, possibly due to faster postoperative recovery, resulting in comparable overall costs for both surgeries [21, 22]. With the implementation of updated medical insurance policies and the progress in magnetic ring technology, the expenses associated with the equipment will be effectively managed, resulting in MSA becoming a financially advantageous surgical procedure.
In this study, the diaphragmatic crura was repaired, as the combination of crura repair with MSA placement improves the integrated relaxation pressure [23]. The esophageal sizer should be tightly placed on the esophagus to ensure the proper positioning of the MSA device. The device should be slightly angled to reduce the risk of severe postoperative dysphagia and produce the most effective outcomes [24]. Patient education on postoperative diet is also essential, as early consumption of large quantities of solid food can lead to food impaction. As a result, we advise patients to consume a liquid diet during the initial week following surgery, gradually transitioning to a semi-liquid diet in the second and third weeks and progressively reintroducing regular food in the fourth week. Most patients may often resume a regular diet within around 1 month.
Although there is evidence of the safety and efficacy of MSA, the current stricter indications of MSA compared to LNF may have introduced a selection bias, contributing to the small sample size in this study. Due to limitations in clinical trials, MSA patients underwent 24-hour acid testing before and after surgery, while the corresponding LNF group patients did not participate in this examination. This study did not consider Psychological factors, which could also impact postoperative follow-up results significantly. Additionally, the limited duration and practical constraints of 24-hour pH monitoring could have resulted in missed GERD diagnoses. However, the 96-hour wireless pH capsule offers a promising solution to this limitation. Wireless, extended-duration monitoring offers improved diagnosis rates [25‐27], better detection of nocturnal acid exposure [28], and diagnosis precision for patients unresponsive to PPIs [29].
Furthermore, future research is anticipated to investigate using MSA to manage greater esophageal hiatal hernia and severe reflux esophagitis. This study performed a one-year follow-up but did not yet have long-term postoperative healing outcomes. In future research, we expect additional progress in MSA technology, with longer observation periods and a wider range of potential uses.
Conclusion
In conclusion, both LNF and MSA are safe and successful surgical therapies for GERD. The benefits of MSA include reduced surgical time, quicker nutritional recovery following surgery, and preservation of hiccup capacity. However, with both surgeries, postoperative dysphagia is a prevalent problem that emphasizes the significance of improving preoperative communication. When selecting between two surgical techniques, it is crucial to consider the postoperative symptoms associated with each procedure.
Acknowledgements
We thank all subjects for their support and understanding of this study and all the participants for their wonderful cooperation.
Declarations
Conflict of interest
The authors declare that they have NO affiliations with or involvement in any organization or entity with any financial interest in the subject matter or materials discussed in this manuscript.
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