Magnetic sphincter augmentation (MSA), utilising the LINX Reflux Management System (LINX, Torax Medical, part of Johnson & Johnson), showed an overall improvement of GERD symptoms and significantly reduced proton pump inhibitor (PPI) use, according to researchers led by University Hospitals Cleveland Medical Center, Cleveland, OH. The outcomes were featured in the paper, ‘Feasibility and Efficacy of Magnetic Sphincter Augmentation for the Management of Gastroesophageal Reflux Disease Post-Sleeve Gastrectomy for Obesity’, published in Obesity Surgery.
The authors stated that although laparoscopic sleeve gastrectomy (LSG) is the most common bariatric procedure, studies have shown that the majority of patients with pre-existing gastroesophageal reflux disease (GERD) who have LSG still present with GERD symptoms. In addition, over a quarter of patients that did not have pre-existing GERD will develop new onset GERD symptoms. Post-LSG weight loss, diet modification, anti-reflux medications and lifestyle changes do not successfully mitigate symptoms and fundoplication - the traditional surgical method of treatment - is not an option for LSG patients due to the resected fundus. Additional surgery, such as Roux-en-Y gastric bypass (RYGB) is an option but carries potential significant complications.
Therefore, the researchers established an Investigational Device Exemption (IDE) study to evaluate the safety and efficacy of MSA as an alternative treatment option for patients experiencing GERD symptoms post-LSG. LINX is a fundic-sparing anti-reflux device placed laparoscopically around the oesophagus at the level of the lower oesophageal sphincter (LES) (Figure 1). The device involves of a series of titanium beads with a magnetic core connected with independent titanium wires to form an annular shape when implanted. The force of the magnetic beads provides additional support to keep a weak LES closed. The authors explained that during swallowing, the magnetic beads slide away from each other on the wire “links” to allow oesophageal distention as the bolus passes by.
This prospective, post-market (approved by the FDA approval in March 2012), single-arm, multi-site observational study was designed to evaluate the safety and efficacy of MSA post-LSG and was conducted from December 2017 to June 2021, at 12 US institutions. Thirty subjects presenting with GERD, who were screened, provided informed consent, and subsequently implanted with a MSA device. All subjects had undergone LSG for obesity at least 12 months prior to proposed implantation with documented symptoms of GERD persisting longer than six months requiring daily PPI or other anti-reflux drug therapy.
Outcomes
The study population consisted of 90.0% female with a mean age of 47.1 years with an average baseline BMI 29.9kg/m2. The mean length of time between LSG and MSA implantation was 3.2 years. New onset GERD symptoms post-LSG surgery were seen in 30.0% of subjects. Hiatal hernia was observed after both endoscopy and esophagram with barium swallow in 63% of subjects at baseline (mean 2.2cm). Subjects reported having GERD symptoms for an average of 11.6 years and taking PPIs for an average of 7.5 years prior to MSA implantation.
The average surgical time for MSA implantation was 58.1±23.3 min with most subjects discharged the same day (0.7 nights ± 0.6). Ninety percent of subjects had concomitant crural or hiatus repair. There was one perioperative complication in a subject who experienced a pneumothorax during LSG staple line dissection off the pleura. The distribution of device size was 15 beads (40.0%), followed by 16 beads (26.7%), 17 beads (23.3%), and 14 bead device (10.0%). The majority of LINX implant procedures were associated with concomitant surgical procedures (90.0%), most commonly hiatal hernia and/or crural repair (90%, aggregate calculation).
Two subjects required device removal at 17 and 121 days respectively. At the three-, six- and 12-month visits, the subject compliance for follow-up was, 29/29, 28/28, and 27/28, respectively. One subject missed the 12-month visit and was determined lost to follow-up. No deaths were reported during the study period.
A total of 21 device- and/or procedure-related adverse events occurred in 15 subjects of which 19 were anticipated. The two unanticipated AEs included one case of moderate intensity face tingling and pain, and one subject experienced mild intensity esophagitis. Both were deemed not serious. Two AEs were deemed serious and occurred in different subjects both of which required hospitalisation longer than 24h. One patient experienced dysphagia, nausea and vomiting which was deemed likely device-related and resulted in device removal. One subject experienced pain requiring prolongation of hospitalisation.
Manometry/motility testing showed no significant abnormal or atypical findings between baseline and 12-month follow-up. Results from barium esophagram evaluations showed normal swallowing function at baseline 100.0%, post-implant prior to discharge 93.3%, and 12 months 96.2%. There were no reported device malfunctions, device migrations or device erosions at 12 months.
The researchers reported a ≥50% reduction in total distal acid exposure in 11/24 subjects and 12/27 of subjects experienced normalization or ≥50% reduction in total acid exposure. pH normalisation was attained in 6/27 subjects. The total percent time in reflux with a ≥50% reduction in total distal acid exposure decreased from 16.2% at baseline to 11.0% at 12 months (p=0.038). At 12 months post-LINX implant, 80.8% of subjects reported at least a 50% reduction in total GERD-HRQL scores when compared with baseline (p<0.001).
Overall, the percentage of subjects who reported being dissatisfied with their GERD symptoms went from 96.7% (29/30) at baseline to 23.1% (6/26) at 12 months. At 12 months, 95.8% subjects experienced a ≥ 50% reduction in daily use of PPI medication (p<0.001) and 84.6% of subjects reported discontinuing all PPIs. The average daily DeMeester score at baseline was 54.1 and at 12 months decreased to 35.1 (p=0.005). The number of daily reflux episodes decreased from a mean of 68.6 to 55.0, with the longest episodes per day decreasing from 45.1 to 29.6 min, respectively.
At baseline, regurgitation occurred 26.4 times/week compared to three-, six-, and 12-month visits, where frequency was 7.9, 1.8, and 4.6 times/week, respectively. Severe regurgitation was reported in 36.7% of subjects at baseline and improved to 3.4% of subjects at three months with no reported cases at six or 12 months. Moderate regurgitation was reported in 43.3% subjects at baseline and at three-, six-, and 12-month visits was 3.4%, 7.7%, and 7.7% of subjects, respectively. Mild regurgitation was reported in 16.7% of subjects at baseline, 27.6% at three months, 23.1% at six months and 30.8% at 12 months.
The number of subjects having no regurgitation increased from baseline (3.3%) to 65.5%, 69.2%, and 61.5% at follow-up (three, six and 12 months). Additionally, 40.0% of subjects reported one or more extra esophageal symptoms at baseline which decreased to 6.9% at three months, 11.5% at six months and 15.4% at 12 months. Based on esophagogastroduodenoscopy testing at baseline, 63.3% of subjects experienced esophagitis which decreased to 11.5% at 12 months post-implant. Grade A esophagitis was reported in 7/30 subjects at baseline while at 12 months, 2/26 had Grade A esophagitis. No Grade B esophagitis was noted at 12 months comparing to the 40.0% at baseline though one subject experienced worsening from Grade B (baseline) to Grade C (12 months).
“In this present study, patients generally tolerated the procedure well with significant improvement in symptoms revealing that MSA can be done safely in the post-LSG population with morbidity similar to that seen in those who had a primary MSA without a sleeve. The intervention was found to be effective in the management of GERD, most notably for improvement of regurgitation, esophagitis, and reduction in PPI use,” the authors concluded. “…Based on the 12-month results of this IDE trial, which specially evaluated MSA in a subject population who had achieved weight loss post-LSG, PPI use is significantly lower and even eliminated in most subjects. Regurgitation is also significantly reduced resulting in improved quality of life. Thus, MSA appears to be safe and effective with comparable morbidity in the treatment of GERD in patients who previously underwent sleeve gastrectomy.”
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