Supplementary Material for: Assessment of the Diagnostic Yield of Multiple Rapid Swallows in Symptomatic Patients with Normal High-Resolution Esophageal Manometry

Introduction: Multiple rapid swallows (MRS) is a provocative maneuver used to assess contractile reserve (CR) in ineffective esophageal motility, but its clinical role in symptomatic patients with normal high-resolution esophageal manometry (HREM) remains unclear. Thus, we aimed to assess the diagnostic ability of MRS for showing any diagnostic yield in these individuals. Methods: A retrospective analysis was performed on 190 patients with normal standard HREM (single liquid swallow) examinations. Patients were categorized as Reflux Symptom Patients (RSP) or Obstructive Symptom Patients (OSP). The CR was defined when the ratio between the highest (maximum) MRS distal contractile integral (DCI) and the mean single swallow DCI was higher than 1.0. Manometric patterns during (normal, abnormal contraction inhibition, or panesophageal pressurization) and after MRS (normal, hypocontractile, spastic pattern, hypercontractile, or panesophageal pressurization) were compared between RSP and OSP. Results: Overall, 49.3% of patients exhibited absent CR with no association between RSP and OSP. No significant association was found between MRS abnormalities and RSP (n=126). In OSP (n=60), the presence of panesophageal pressurization during MRS (p = 0.015) and a spastic pattern after MRS (p < 0.001) were significantly associated with dysphagia. In 13 instances in OSP, MRS highlighted features of other motor diseases: 11 with spastic pattern and 2 with hypercontractility. Conclusion: MRS did not provide additional diagnostic benefit over standard HREM for esophageal dysmotility in patients with only reflux symptoms and normal baseline examinations. In obstructive complaints, MRS stimulated some motor abnormalities (panesophageal pressurization and spastic pattern) that were significantly associated with dysphagia, suggesting its potential diagnostic value as a complementary tool in this subgroup of patients.