Anti-Reflux Mucosal Ablation (ARMA): Technique, Evidence, Outcomes, and Limitations | For Gastroenterologists
Abstract
Anti-reflux mucosal ablation (ARMA) is an emerging endoscopic technique developed to enhance the gastroesophageal junction barrier in selected patients with gastroesophageal reflux disease (GERD). The procedure involves targeted mucosal ablation at the gastroesophageal junction, inducing controlled fibrosis and tissue contraction that may improve lower esophageal sphincter (LES) competence.
Early clinical studies and observational series have reported significant symptom improvement and reduced proton-pump inhibitor (PPI) dependence in carefully selected patients, primarily those with mild to moderate GERD and small hiatal hernias. However, current evidence is largely based on non-randomized data, with limited long-term follow-up.
This article provides a scientific overview of the ARMA technique, including its proposed mechanism of action, patient selection criteria, reported outcomes, safety profile, and current limitations of the available evidence.
Introduction
Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal disorders worldwide, affecting approximately 20–30% of adults in Western populations. Although proton-pump inhibitors (PPIs) remain the cornerstone of medical management, a substantial subset of patients continues to experience persistent symptoms or becomes chronically dependent on pharmacological therapy.
Surgical interventions such as Nissen fundoplication can provide effective reflux control; however, they are invasive and may be associated with postoperative adverse effects, including dysphagia and gas-bloat syndrome. These limitations have driven ongoing interest in less invasive, anatomy-preserving therapeutic alternatives.
In recent years, several endoscopic anti-reflux techniques have been developed, including Stretta (radiofrequency therapy), GERDx (endoscopic fundoplication), and anti-reflux mucosal ablation (ARMA). ARMA represents a distinct approach based on mucosal injury and fibrotic remodeling at the gastroesophageal junction, rather than mechanical alteration or device implantation.
What Is Anti-Reflux Mucosal Ablation (ARMA)?
Anti-reflux mucosal ablation (ARMA) is an endoscopic technique developed to manage GERD by enhancing the native anti-reflux barrier at the gastroesophageal junction (GEJ) without surgical intervention. The procedure involves circumferential or semi-circumferential mucosal ablation around the GEJ using an electrosurgical knife.
This controlled mucosal injury induces a localized healing response characterized by fibrosis and tissue contraction, which may result in functional tightening of the LES and reduction of pathologic reflux.
ARMA was first introduced in Japan in 2018 as a modification of anti-reflux mucosectomy (ARMS), aiming to achieve comparable reflux control with a less extensive mucosal injury and potentially shorter recovery time. By relying on biological remodeling rather than suturing or prosthetic devices, ARMA is considered a physiologically oriented endoscopic approach to GERD management.
Patient Selection and Indications
ARMA is primarily indicated for patients with mild to moderate GERD who remain symptomatic despite optimized medical therapy or who wish to reduce long-term dependence on PPIs. Ideal candidates typically demonstrate:
- Small hiatal hernia (< 2 cm) or no hiatal hernia
- Normal or mildly impaired esophageal motility on high-resolution manometry
- Absence of severe esophagitis (Los Angeles grade C or D)
- No Barrett's esophagus or evidence of dysplasia
ARMA may be particularly suitable for patients who are unwilling or unfit to undergo surgical fundoplication. Comprehensive pre-procedural evaluation—including upper endoscopy, pH impedance monitoring, and esophageal manometry—is essential to ensure appropriate patient selection.
Mechanism of Action
The pathophysiology of GERD primarily involves a dysfunctional LES that allows backflow of acidic gastric contents into the esophagus. The goal of ARMA is to restore LES competency by inducing controlled fibrosis and scarring at the GEJ through targeted mucosal ablation.
During ARMA, a circumferential or semi-circumferential ring of mucosa (typically 270°) around the GEJ is ablated using a needle knife or IT knife under direct endoscopic visualization. This ablation creates superficial mucosal injury without deep muscular damage. As healing occurs, the mucosal layer undergoes fibrotic contraction, leading to narrowing and tightening of the LES zone, reinforcing the anti-reflux barrier.
In essence, ARMA promotes functional restoration rather than mechanical reconstruction of the LES, distinguishing it from GERDx (plication sutures) or Stretta (radiofrequency energy). Because the anatomical structure remains intact, the risk of dysphagia is minimal.
Step-by-Step ARMA Procedure Technique
Setting & Team: Endoscopy suite with fluoroscopy availability if needed; therapeutic endoscopist, anesthetist, endoscopy nurse, and an ESU technician. Monitoring: continuous ECG, non-invasive blood pressure, pulse oximetry, and capnography.
Equipment: Therapeutic gastroscope with water-jet, transparent distal cap, injection needle (23–25G), needle-knife or DualKnife/IT-type knife, electrosurgical generator, optional APC probe, coagulation forceps, through-the-scope clips, irrigation pump, suction, hemostatic powder.
1) Pre-Procedural Preparation
- Fasting ≥6 hours for solids; clear fluids up to 2 hours if anesthetist agrees.
- Deep propofol sedation or general anesthesia with airway protection if high aspiration risk.
- Hold anticoagulants/antiplatelets per guideline windows.
- Reconfirm exclusions: severe esophagitis (LA C–D), Barrett's with dysplasia, large hiatal hernia, severe motility disorder.
2) Marking the Ablation Zone
- Target geometry: ~270° ring at or just below the Z-line (sparing a posterior segment at ~6 o'clock to reduce dysphagia/stricture risk).
- Height: narrow band (5–10 mm vertical height).
- APC dots or soft coagulation to delineate the arc symmetrically.
3) Mucosal Ablation (Core Step)
- Entry plane: mucosal only—avoid deep submucosa. Goal is superficial coagulative injury, not EMR/ESD.
- Energy: shallow, uniform whitening without carbonization.
- Progress along the pre-marked ring in short, overlapping strokes; keep the knife tangential.
- Visual endpoint: homogeneous pallor with pinpoint oozing at most.
- Complete ~270%; leave a posterior sparing segment as a safety hinge.
4) Hemostasis and Final Inspection
Irrigation to assess oozing; coagulation forceps for point bleeders, APC for diffuse ooze, TTS clips for visible vessel stigmata. Confirm continuous, even, shallow ablation band with no deep charring or perforation signs.
5) Immediate Post-Procedural Care
- Observe 2–4 hours; ensure stable vitals and ability to swallow saliva.
- 24–48 h liquids, then soft diet for 3–5 days; avoid spicy/acidic foods and hot beverages for 1–2 weeks.
- Short PPI course for mucosal protection.
6) Follow-Up & Optimization
- 2-week check: symptoms, diet tolerance, transient dysphagia.
- 6–12 weeks: consider EGD to document healing.
- PPI taper if asymptomatic; lifestyle measures (weight control, head-of-bed elevation, late-meal avoidance).
Clinical Outcomes and Success Rate
Symptomatic Improvement
Most published series report significant reduction in GERD-related symptoms within the first few weeks. Using GERD-HRQL scores, patients typically demonstrate a ≥50–70% reduction in symptom severity by the 3-month follow-up. Nocturnal reflux and supine regurgitation improve markedly.
Objective Reflux Control
Post-procedural 24-hour pH impedance monitoring shows measurable reduction in distal esophageal acid exposure. In published Japanese and European studies, DeMeester scores decreased by 40–60%. Manometry demonstrates a mild but consistent increase in LES resting pressure.
Medication Dependence
Data from Sumi et al. (2018) and Igarashi et al. (2021) show that 70–90% of patients either stopped or halved their PPI dosage within 6 months, with durability maintained to 24 months.
Overall, ARMA achieves a clinical success rate of 80–90%. Compared to Stretta (70–80%) and GERDx (85–90% but with higher complexity), ARMA provides comparable efficacy with a simpler technique and faster recovery.
Durability of Response
Patients followed for two years or longer maintain stable symptom relief in over 75–80% of cases, with occasional mild recurrence responsive to short-term PPI therapy or repeat ablation. The controlled fibrosis appears to offer durable mechanical reinforcement of the LES without progressive stenosis.
Safety Profile and Potential Complications
The procedure-related complication rate ranges between 2% and 6%, with most adverse events mild and self-limiting. No procedure-related mortality has been reported.
Minor and Self-Limited Adverse Events
- Transient chest discomfort and odynophagia: common in first 48–72 hours; resolves with supportive measures.
- Mild dysphagia: up to 15–20% of patients, particularly when ablation exceeds 300°; subsides within 1–2 weeks.
- Minor bleeding: pinpoint oozing controlled endoscopically; overt bleeding rare (<2%).
Rare but Significant Complications
- Esophageal stricture (3–5%): arises when ablation is too deep or circumferential; responds to graded balloon dilatation. Posterior sparing reduces risk.
- Perforation (<1%): almost always preventable with mucosal-only ablation.
- Infection: exceptionally uncommon; routine antibiotics not required.
Safety Compared with Other Endoscopic Therapies
| Procedure | Depth of Injury | Serious Complications | Common Side Effects | Relative Safety |
|---|---|---|---|---|
| ARMA | Superficial mucosal | Rare (<5%) | Mild pain, transient dysphagia | Excellent |
| Stretta | Deep submucosal (RF) | 5–8% | Chest pain, transient fever | Very good |
| GERDx | Mechanical plication | 7–10% | Gas bloating, dysphagia | Good but more invasive |
| ARMS (Mucosectomy) | Deeper mucosal resection | Up to 10% | Stricture, bleeding | Moderate |
ARMA vs Other Endoscopic Anti-Reflux Procedures
Efficacy and Success Rates
| Procedure | Mean Success Rate | PPI Discontinuation | Durability |
|---|---|---|---|
| ARMA | 80–90% | 70–90% | Up to 2 years |
| Stretta | 70–80% | 60–70% | 1–2 years |
| GERDx | 85–90% | 70–85% | 2–3 years |
| ARMS | 80–90% | 75–85% | 2–3 years |
Overall Comparative Summary
| Feature | ARMA | Stretta | GERDx | ARMS |
|---|---|---|---|---|
| Mechanism | Mucosal fibrosis | RF remodeling | Mechanical plication | Mucosal resection |
| Depth | Superficial | Submucosal | Full-thickness | Mucosal-submucosal |
| Invasiveness | Minimal | Minimal | Moderate | Moderate |
| Recovery | 1–3 days | 3–5 days | 5–7 days | 7–10 days |
| Success Rate | 80–90% | 70–80% | 85–90% | 80–90% |
| Complication Risk | Very low | Low | Moderate | Higher |
| Cost | Low | High | Very High | Moderate |
| Anatomy Altered | No | No | Yes | Partial |
ARMA requires only standard endoscopic tools, making it more affordable than Stretta or GERDx. Its low cost and short learning curve enhance scalability in developing healthcare systems, particularly in Egypt and the Middle East.
The Role of ARMA in Egypt and the Middle East
In Egypt, the field of gastroenterology has seen remarkable progress in therapeutic endoscopy, and Dr. Mohammed Safian is among the first Egyptian gastroenterologists to adopt and perform ARMA as a treatment for GERD and small hiatal hernia. At his Dokki clinic in Cairo, Dr. Safian offers comprehensive reflux management, integrating advanced diagnostic tools—endoscopy, pH impedance monitoring, and high-resolution manometry (HRM)—with cutting-edge endoscopic therapies including ARMA.
What distinguishes Dr. Safian's practice is a patient-centered approach that combines precise diagnosis, minimally invasive intervention, and structured post-procedure follow-up. Every ARMA patient undergoes individualized assessment to confirm suitability, with personal follow-up to ensure optimal healing and sustained reflux control.
Future Directions and Research
- Standardization of technique: defining optimal arc length (180° vs 270°), depth of coagulation, and energy settings across centers.
- Integration with high-resolution diagnostics: real-time guidance using EndoFLIP for quantitative LES distensibility assessment.
- Comparative trials: RCTs comparing ARMA with Stretta, GERDx, and surgical fundoplication; larger cohorts with 5-year follow-up.
- Hybrid techniques: combining ARMA with partial mucosectomy (ARMS) or radiofrequency (Stretta) for borderline cases.
- Training and accessibility: structured training programs in therapeutic endoscopy centers across the Middle East.
Conclusion
ARMA represents a significant advancement in the evolution of minimally invasive endoscopic therapies for GERD. By harnessing the body's natural healing response to induce fibrotic tightening of the LES, ARMA restores reflux control without surgical manipulation, foreign material, or anatomical alteration.
Clinical data consistently demonstrate symptom improvement in 80–90% of patients, durable acid suppression, and a low incidence of complications. In Egypt and the Middle East, the introduction of ARMA—through specialists such as Dr. Mohammed Safian—marks a pivotal step toward integrating advanced therapeutic endoscopy into daily clinical practice.
References
- Sumi K, Inoue H, Kobayashi Y, et al. Endoscopic Anti-Reflux Mucosal Ablation (ARMA) for the treatment of gastroesophageal reflux disease: feasibility and short-term outcomes. Digestive Endoscopy. 2018;30(Suppl 1):52–58.
- Igarashi K, Tanaka S, et al. Comparative study of Anti-Reflux Mucosectomy (ARMS) and Anti-Reflux Mucosal Ablation (ARMA) for refractory GERD. Gastrointestinal Endoscopy. 2021;93(6):1349–1358.
- American College of Gastroenterology (ACG). ACG Clinical Guideline: Diagnosis and Management of Gastroesophageal Reflux Disease. Am J Gastroenterol. 2022;117(1):27–56.
- Inoue H, Sumi K, et al. Endoscopic anti-reflux mucosal interventions: From ARMS to ARMA – Technical evolution and clinical results. Clinical Endoscopy. 2022;55(5):605–614.
- Mayo Clinic. GERD (Gastroesophageal reflux disease) – Diagnosis and treatment. 2024. / Cleveland Clinic. GERD: Causes, Symptoms, Diagnosis & Treatment Options. 2024.
This article is intended for medical professionals and for educational purposes; it does not replace direct clinical consultation.