Phenotyping patients with borderline elevated esophageal acid exposure

Summary Acid exposure time (AET) <4% on ambulatory reflux monitoring definitively rules out pathologic gastroesophageal acid reflux, while AET >6% indicates pathologic reflux per the Lyon Consensus, leaving AET of 4–6% as borderline. We aimed to elucidate the borderline AET population and identify metrics that could help differentiate this group. A total of 50 subjects in each group, AET <4, 4–6, and >6% on pH-impedance monitoring between 2015 and 2019, were retrospectively reviewed. In addition to demographic and clinical information, the extracted data included mean nocturnal baseline impedance (MNBI) on reflux study and high-resolution manometry (HRM) parameters and diagnosis. After excluding patients with prior foregut surgery, major esophageal motility disorder, or unreliable impedance testing, a total of 89 subjects were included in the analysis (25 with normal AET < 4%, 38 with borderline 4–6%, 26 with abnormal >6%). MNBI in borderline AET patients was significantly lower compared to normal AET (1607.7 vs. 2524.0 ohms, P < 0.01), and higher than abnormal AET (951.5 ohms, P < 0.01). Borderline subjects had a greater frequency of ineffective esophageal motility (IEM) diagnosis per Chicago classification v3.0 (42.1 vs. 8.0%, P = 0.01), but did not demonstrate any differences compared to abnormal subjects (34.6%, P = 0.56). Patients with borderline AET had an average MNBI that was in between normal AET and abnormal AET. Borderline AET patients also commonly demonstrate IEM on HRM, similar to those with abnormal AET. Our findings can be potentially useful in assigning higher clinical significance for patients found to have borderline AET with concomitant low MNBI and IEM on manometry.

Multiple Esophageal Leiomyoma Presenting with Clinical Dysphagia from Mechanical Obstruction and Motility Disorder

Esophageal leiomyoma is uncommon. However, this tumor is the most common subepithelial tumor affecting the esophagus, comprising approximately two-thirds of benign esophageal tumors. Leiomyomas of the esophagus rarely cause symptoms when they are single and <5 cm. The mainstay of treatment is esophagectomy for symptomatic patients. A 68-year-old male patient presented with progressive dysphagia for 4 months. The degree of dysphagia and chest discomfort was more severe on solid rather than liquid diet. The CT scan of the chest showed multiple well-defined, submucosal nodules, up to 1.9 cm in diameter located at the middle esophagus. The barium swallow study illustrated multiple, well-defined, smooth, semilunar filling defects along the mid to distal esophagus. Meanwhile, esophagogastroduodenoscopy revealed 8 smooth subepithelial masses. Moreover, the radial EUS showed multiple hypoechoic masses arising from the 4th layer, with some of the tumors connected to others as a horseshoe-like shape causing narrowed lumen. Last, high-resolution esophageal manometry revealed ineffective esophageal motility. We report a rare case of numerous esophageal leiomyomas which caused dysphagia as a result of both mechanical obstruction and hypomotility disorder. The histopathology confirmed the diagnosis of esophageal leiomyoma. Symptoms improved significantly after lifestyle modifications and adherence to dietary advice on the part of the patient.

Ineffective Esophageal Motility: Need for Improvement in Diagnostic Criteria

Ineffective esophageal motility (IEM) is a hypomotility disorder with decreased contraction vigor and normally relaxing lower esophageal sphincter. Although IEM has been associated with poor esophageal clearance and gastroesophageal reflux, it is also seen in asymptomatic subjects and is often of unclear clinical significance. The Chicago classification version 4.0 updated the diagnostic threshold to require >70% weak or fragmented swallows or ≥50% failed swallows for a conclusive diagnosis of IEM. Provocation testing are recommended in borderline cases to assess clinical relevance. Prospective trials are needed to further refine the diagnostic criteria, understand the pathophysiology, and develop an effective treatment for IEM.

807 ASSOCIATION OF BOLUS TRANSIT TIME ON BARIUM ESOPHAGOGRAM WITH ESOPHAGEAL PERISTALSIS

The threshold criteria for diagnosing ineffective esophageal motility (IEM) has changed over the years and is based on the proportion of failed and weak peristalses. Bolus transit time (BTT) on barium esophagogram (BE) can intuitively be the ‘gold standard' for assessing the effectiveness of esophageal peristalsis. The aim of this study was to associate upright and prone BTT with esophageal peristalsis and dysphagia in patients with normal lower esophageal sphincter (LES) parameters. Methods Patients with normal LES on high-resolution manometry (HRM) who also had a standard-protocol BE from 2017 to 2020 were included. Patients with previous foregut surgery, hiatal hernia, jackhammer esophagus, distal esophageal spasm, fragmented peristalsis, and those with < or > 10 single swallows on HRM were excluded. Based on the number of normal swallows (DCI >450 mmHg.s.cm), the patients were divided into 11 groups (10 normal to 0 normal). Upright and prone BTT were measured on BE. Fractional polynomial and logistic regression analysis were used to study association (along with rate of change) between BTT, dysphagia, and peristalsis. Results In total, 146 patients met the inclusion criteria. Prone BTT increased in tandem with a decrease in the number of normal peristalses (p < 0.001), but no difference was noted in upright BTT (p = 0.317). Two deflection points were noted on the association between peristalsis and prone BTT at 50%, 40 seconds and 30%, 80 seconds on the y and x-axes, respectively, after which declining peristaltic function was independent of prone BTT. Patients with prone BTT >40 seconds had nearly 6-fold higher odds of having zero normal peristalses (p = 0.002). Increasing prone BTT was associated with increasing dysphagia (p < 0.05). Conclusion Prone, but not upright BTT, correlates with the proportion of normal esophageal peristalses and dysphagia. The phenotype of abnormal swallows (failed, weak) appears to have minimal impact on BTT. The current perspective of manometric classification may need to be adjusted to use the proportion of normal peristalses as a criterion.

153 THE CLINICAL SIGNIFICANCE OF INCOMPLETE BOLUS CLEARANCE IN PATIENTS WITH DYSPHAGIA

The primary function of the esophagus is to facilitate bolus transport to the stomach. High-resolution manometry assesses the functions of esophageal motility, but not the clearance of bolus transit through the esophagus. The development of combined multichannel intraluminal impedance and manometry (MII-EM) has enabled simultaneous measurement of bolus transport and manometry. This study investigated the effects of bolus transit on esophageal motility disorders and its effect on the quality of life of patients with dysphagia. Methods A total of 810 wet swallows were reviewed and analyzed in 81 patients with dysphagia who underwent MII-EM. Incomplete bolus clearance (IBC) was defined based on impedance measurement. IBC was classified into four types (A: normal, B: incomplete clearance in the upper esophagus, C: incomplete clearance in the lower esophagus, D: incomplete clearance of the whole esophagus), and was also evaluated according to the appearance rate of complete bolus transit. Then, the clinical significance of IBC was determined by our previously validated dysphagia symptom score and the SF8 quality of life instrument (physical component summary and mental component summary). Results There were 16 cases of esophageal achalasia (Ach), 9 of esophagogastric junction outflow obstruction (EGJOO), 8 of distal esophageal spasm (DES), 7 of Jackhammer esophagus (JE), 2 of absent contractility (AC), 10 of ineffective esophageal motility (IEM) and 29 normal cases. The figure shows the breakdown of IBC for each disorder. Complete bolus transit was found in 27.8% in EGJOO, 52.5% in DES, 14.2% in JE, 4.0% in IEM, and 83.3% in normal; no CBT was found in Ach and AC. Patients with IBC had significantly higher dysphagia symptom scores (p < 0.05) and lower mental component summaries (p < 0.05) than those without. Conclusion Patients with dysphagia with esophageal dysmotility were classified into two groups: those with and without IBC. Assessment of bolus transport is an important clinical marker for patients with dysphagia, because those with IBC had a significantly higher dysphagia symptom scores and impaired quality of life.

The Relevance of Ineffective Esophageal Motility to Surgical Practice

Foregut surgery is often complicated by postoperative dysphagia. Preoperative esophageal manometry has been used to counsel patients and to guide choice of operation to minimize dysphagia outcomes. Uncertainty surrounds the optimal surgical management of patients with disordered motility. While treatment protocols are generally accepted for the disorders of esophagogastric junction outflow, surgery choice in the presence of disorders of peristalsis, particularly ineffective esophageal motility (IEM), is less clear. With the diagnosis of IEM, provocation testing is being utilized to predict postoperative dysphagia and to guide management, though evidence is not yet sufficient to allow for strong recommendations.