Evaluation of esophageal motor disorders in the era of high-resolution manometry and intraluminal impedance

Swallowing Rehabilitation: Tracing the Evolution of Assessment and Intervention Approaches for Dysphagia over 30 Years

Dysphagia or difficulty in swallowing is a common condition affecting millions worldwide. It can occur due to structural problems, neurological disorders, cancer treatment, aging, etc. Swallowing rehabilitation aims to help patients regain safe and efficient swallowing function through compensatory strategies and exercises. This literature review examines the recent advancements in swallowing rehabilitation techniques over the past three decades, with a focus on innovations in diagnostics, personalized medicine, and patient care.

Development and Evaluation of a Flexible PVDF-Based Balloon Sensor for Detecting Mechanical Forces at Key Esophageal Nodes in Esophageal Motility Disorders

Prevailing methods for esophageal motility assessments, such as perfusion manometry and probe-based function imaging, frequently overlook the intricate stress fields acting on the liquid-filled balloons at the forefront of the probing device within the esophageal lumen. To bridge this knowledge gap, we innovatively devised an infusible flexible balloon catheter, equipped with a quartet of PVDF piezoelectric sensors. This design, working in concert with a bespoke local key-node analytical algorithm and a sensor array state analysis model, seeks to shed new light on the dynamic mechanical characteristics at pivotal esophageal locales. To further this endeavor, we pioneered a singular closed balloon system and a complementary signal acquisition and processing system that employs a homogeneously distributed PVDF piezoelectric sensor array for the real-time monitoring of dynamic mechanical nuances in the esophageal segment. An advanced analytical model was established to scrutinize the coupled physical fields under varying degrees of balloon inflation, thereby facilitating a thorough dynamic stress examination of local esophageal nodes. Our rigorous execution of static, dynamic, and simulated swallowing experiments robustly substantiated the viability of our design, the logical coherence of our esophageal key-point stress analytical algorithm, and the potential clinical utility of a flexible esophageal key-node stress detection balloon probe outfitted with a PVDF array. This study offers a fresh lens through which esophageal motility testing can be viewed and improved upon.

High-Resolution Manometry-Observations After 15 Years of Personal Use-Has Advancement Reached a Plateau?

PURPOSE OF REVIEW

In the absence of mucosal or structural disease, the aim of investigating the oesophagus is to provide clinically relevant measurements of function that can explain the cause of symptoms, identify pathology and guide effective management. One of the most notable recent advances in the field of oesophageal function has been high-resolution manometry (HRM). This review explores how innovation in HRM has progressed and has far from reached a plateau.

RECENT FINDINGS

HRM technology, methodology and utility continue to evolve; simple additions to the swallow protocol (e.g. eating and drinking), shifting position, targeting symptoms and adding impedance sensors to the HRM catheter have led to improved diagnoses, therapeutic decision-making and outcomes. Progress in HRM persists and shows little sign of abating. The next iteration of the Chicago Classification of motor disorders will highlight these advances and will also identify opportunities for further research and innovation.

Combined Multichannel Intraluminal Impedance and High-resolution Manometry Improves Detection of Clinically Relevant Esophagogastric Junction Outflow Obstruction

BACKGROUND/AIMS

Esophagogastric junction outflow obstruction (EGJOO) is a diagnostically heterogeneous group with variable clinical relevance. We studied whether evaluation of bolus transit by multichannel intraluminal impedance (MII) is useful for discriminating clinically relevant EGJOO.

METHODS

A total 169 patients diagnosed as having EGJOO between June 2011 and February 2018 were analyzed. All the patients received a combined MII and high-resolution manometry (CMII-HRM). MII was reported as having abnormal liquid bolus transit (LBT) if ＜ 80% of swallows had complete bolus transit. EGJOO was defined as a median integrated relaxation pressure of ＞ 20 mmHg and when the criteria for achalasia were not met. Patients who progress to achalasia, show significant passage disturbance, or require pneumatic dilatation were defined as having a clinically relevant EGJOO.

RESULTS

Among the patients with EGJOO (n = 169), the clinically relevant group (n = 10) is more likely to have dysphagia (100% vs 25.2%, P ＜ 0.001), compartmentalized pressurization (CP; 90.0% vs 22.0%, P ＜ 0.001), and abnormal LBT (100% vs 66.7%, P = 0.032) compared to the non-relevant group (n = 159). The combination of dysphagia, CP, and abnormal LBT showed the best predictive power for clinically relevant EGJOO (sensitivity 90%, specificity 92.5%, positive predictive value 42.9%, negative predictive value 99.3%, positive likelihood ratio 11.9, and negative likelihood ratio 0.1). When CMII-HRM was used, an additional 8.3% of clinically relevant EGJOO cases were identified as compared with HRM alone.

CONCLUSION

Clinically relevant EGJOO can be predicted using CMII-HRM.

What Is the Future of Impedance Planimetry in Gastroenterology?

The gastrointestinal (GI) tract is efficient in transporting ingested material to the site of delivery in healthy subjects. A fine balance exists between peristaltic forces, the mixing and delivery of the contents, and sensory signaling. This fine balance is easily disturbed by diseases. It is mandatory to understand the pathophysiology to enhance our understanding of GI disorders. The inaccessibility and complex nervous innervation, geometry and mechanical function of the GI tract make mechanosensory evaluation difficult. Impedance planimetry is a distension technology that assesses luminal geometry, mechanical properties including muscle dynamics, and processing of nociceptive signals from the GI tract. Since standardized models do not exist for GI muscle function in vivo, models, concepts, and terminology must be borrowed from other medical fields such as cardiac mechanophysiology. The review highlights the impedance planimetric technology, muscle dynamics assessment, and 3 applied technologies of impedance planimetry. These technologies are the multimodal probes that assesses sensory function, the functional luminal imaging probe that dynamically measures the geometry of the lumen it distends, and Fecobionics that is a simulated feces providing high-resolution measurements during defecation. The advanced muscle analysis and 3 applied technologies can enhance the quality of future interdisciplinary research for gaining more knowledge about mechanical function, sensory-motor disorders, and symptoms. This is a step in the direction of individualized treatment for GI disorders based on diagnostic subtyping. There seems to be no better alternatives to impedance planimetry, but only the functional luminal imaging probe is currently commercially available. Wider use depends on commercialization of the multimodal probe and Fecobionics.

Esophagogastric junction outflow obstruction is often associated with coexistent abnormal esophageal body motility and abnormal bolus transit

Currently, the diagnosis of esophageal motility disorders is in part based upon a hierarchical algorithm in which abnormalities of the esophagogastric junction (EGJ) is prioritized. An important metric in evaluating the EGJ is the integrated relaxation pressure (IRP). Patients who do not have achalasia but are found to have an elevated IRP are diagnosed with EGJ outflow obstruction. It has been our observation that a subset of these patients also has a second named motility disorder and may also have abnormal bolus transit. The aim of this study is to determine the frequency of abnormal body motility and or abnormal bolus movement in patients with EGJ outflow obstruction. Further, in an effort to evaluate the potential clinical value in measuring bolus transit as a complement to esophageal manometry, specifically in patients with EGJ outflow obstruction, we analyzed the presenting symptoms of these patients. A total of 807 patients with a mean age of 53 years completed esophageal function testing with impedance monitoring and high-resolution manometry between January 2012 and October 2016. There were 74 patients with achalasia who were excluded from the study. Of the remaining 733 patients, 138 (19%) had an elevated IRP and were given a diagnosis of EGJ outflow obstruction. Among these patients, 56 (40%) were diagnosed with an abnormal motility pattern to liquids (ineffective esophageal motility = 28, distal esophageal spasm = 19, Jackhammer = 6), of which 44 (76%) had abnormal bolus transit to liquids, viscous, or both. In contrast, there were 82 patients with EGJ outflow obstruction and normal esophageal motility, of which 33 (40%) had abnormal bolus transit. Patients with preserved esophageal motility and EGJ outflow obstruction were then evaluated. Of the 733 patients, 299 (40%) had intact esophageal motility. Of the 299 patients with normal esophageal motility, 56 patients had an elevated IRP, of which 16 (28%) had abnormal bolus transit. There were 243 (33%) patients with intact esophageal motility and normal IRP. Of these, 56 (23%) patients had abnormal bolus transit. Among patients with abnormal bolus transit, the two most commonly presenting symptoms were dysphagia and heartburn. A substantial percentage of patients with EGJ outflow obstruction have abnormal esophageal body motility and or abnormal bolus transit. The clinical implications of EGJ outflow obstruction need to be further elucidated as current criteria do not allow for the description of other abnormalities in esophageal motility and bolus transit among patients who are given the diagnosis of EGJ outflow obstruction.

The effect of intravenous corticotropin-releasing hormone administration on esophageal sensitivity and motility in health

Esophageal hypersensitivity is important in gastroesophageal reflux disease (GERD) patients who are refractory to acid-suppressive therapy. Stress affects visceral sensitivity and exacerbates heartburn in GERD. Peripheral CRH is a key mediator of the gut stress response. We hypothesize that CRH increases esophageal sensitivity and alters esophageal motility in health. Esophageal sensitivity to thermal, mechanical, electrical, and chemical stimuli was assessed in 14 healthy subjects after administration of placebo or CRH (100 μg iv). Perception scores were assessed for first perception, pain perception threshold (PPT), and pain tolerance threshold (PTT). Esophageal motility was investigated by high-resolution impedance manometry, before and after CRH and evaluated by distal contractile integral (DCI) and intrabolus pressure (IBP). Pressure flow analysis assessed bolus clearance (impedance ratio), degree of pressurization needed to propel bolus onward (IBP slope), and pressure flow (pressure flow index, PFI). Stress and mood were assessed during the study. Sensitivity to mechanical distention was increased after CRH compared with placebo (PPT: P = 0.0023; PTT: P = 0.0253). CRH had no influence on the other stimulations. DCI was increased for all boluses (liquid, P = 0.0012; semisolid, P = 0.0017; solid, P = 0.0107). Impedance ratio for liquid (P < 0.0001) and semisolid swallows (P = 0.0327) decreased after CRH. IBP slope increased after CRH for semisolid (P = 0.0041) and solid (P = 0.0003) swallows. PFI increased for semisolid (P = 0.0017) and solid swallows (P = 0.0031). CRH increased esophageal sensitivity to mechanical distention, not to the other stimulation modalities. CRH increased esophageal contractility and tone, decreased LES relaxation, increased esophageal bolus pressurization, improved esophageal bolus clearance, and increased pressure flow.NEW & NOTEWORTHY This is the first study to address the effect of corticotropin-releasing hormone (CRH) on esophageal sensitivity and alterations in motility in health. CRH administration increased esophageal sensitivity to mechanical distention. This effect is accompanied by an increase in esophageal contractility and tone and a decrease in lower esophageal sphincter relaxation. CRH increased esophageal bolus pressurization, improved esophageal bolus clearance, and increased pressure flow. The changes in esophageal contractile properties may underlie the increased sensitivity to mechanical distention after CRH.

Beneficial effect of the 5-HT1A receptor agonist buspirone on esophageal dysfunction associated with systemic sclerosis: A pilot study

BACKGROUND

Esophageal involvement in systemic sclerosis (SSc) carries significant morbidity and is empirically managed with domperidone, albeit with questionable efficacy. The oral 5-HT1A receptor agonist buspirone may enhance esophageal peristalsis and lower esophageal sphincter (LES) function in healthy volunteers.

AIM

We aimed to test the hypothesis that buspirone may exert a beneficial acute effect on esophageal motor dysfunction in symptomatic patients with SSc.

METHODS

Twenty consecutive patients with SSc reporting esophageal symptoms underwent high-resolution manometry before and 30 minutes after administration of buspirone (10 mg). Ten other patients received domperidone (10 mg) and served as control group. Changes in LES resting and residual pressure, amplitude, duration, and velocity of distal esophageal body contractions were examined.

RESULTS

Esophageal hypomotility and hypotensive LES was found in 63% and 67% of patients, respectively. Demographic and clinical characteristics, including baseline manometric parameters, were comparable between groups. Resting pressure of LES increased after buspirone from 9.42 ± 2.6 to 11.53 ± 3.4 mmHg (p = 0.0002 by paired t-test), but not after domperidone; a trend for increase of amplitude of contractions was also observed after buspirone (p = 0.09). Comparison of the individual changes revealed that buspirone was superior to domperidone in enhancing LES pressure ( + 2.11 ± 2.0 versus -0.45 ± 2.3 mmHg, p = 0.006). No significant effects of either drug were noted on other examined parameters of esophageal function.

CONCLUSION

The beneficial acute effect of buspirone on impaired LES function associated with SSc suggests a role of 5-HT1A receptor-mediated interactions in these patients. Prospective studies to examine whether buspirone is of long-term therapeutic value for SSc-associated esophageal disease are warranted.

Assessment of esophageal dysfunction and symptoms during and after a standardized test meal: development and clinical validation of a new methodology utilizing high-resolution manometry

BACKGROUND

In the absence of major dysmotility, esophageal manometry with water swallows rarely explains the causes of esophageal symptoms and disease. This methodology development study assessed esophageal function and symptoms during a test meal in patients with reflux symptoms and asymptomatic controls. The impact of this approach on manometric diagnosis and clinical outcome was reviewed.

METHODS

18 patients with reflux symptoms and 10 healthy volunteers underwent high resolution manometry (HRM) with 5 mL water swallows, 200 mL water drink, and standardized solid test meal followed by 10 min postprandial observation. The number of symptoms associated with esophageal dysfunction (SAD) divided by total symptoms (dysfunction symptom index [D-SI]) was calculated. Ambulatory reflux pH-monitoring was performed. Final diagnosis and clinical outcome were documented at 2 years.

KEY RESULTS

Meal intake took longer in patients than controls (552 vs 339 s) and this was associated with a higher number of ineffective swallows in this group (51% vs 28%; p < 0.001). No swallowing problems occurred with water swallows but 12/18 (66%) patients had SAD during either the meal or postprandial observations with D-SI >50% in 9/12 (75%). Compared with water swallows, manometric classification was altered in 12/18 (67%) and clinical diagnosis was altered in 7/18 (39%) patients due to test meal observations.

CONCLUSIONS & INFERENCES

A novel methodology for the detection of symptomatic dysmotility during a test meal and postprandial observation is presented. This technique increased the diagnostic yield of esophageal dysfunction in patients presenting with reflux symptoms. Long-term follow-up indicated that these observations can guide effective clinical management.

Effect of buspirone, a 5-HT1A receptor agonist, on esophageal motility in healthy volunteers

There are limited data concerning the effects of 5-HT(1A) receptor activation on esophageal motility. Sumatriptan, a 5-HT(1A) receptor agonist, was recently reported to enhance esophageal peristalsis after intravenous administration. Buspirone, an orally available 5-HT(1A) receptor agonist, was shown to modulate gastroduodenal motor function. Our aim was to evaluate the effect of buspirone on esophageal motility of healthy volunteers. On two separate visits, 20 healthy volunteers aged 21-29 years (nine women) underwent esophageal manometry before and 10, 30, and 60 minutes after the administration of buspirone 20-mg or placebo capsule, according to a double-blind crossover design. At each time point, we compared buspirone and placebo effects on: resting pressure of the lower esophageal sphincter (LES); residual pressure and duration of LES relaxation; amplitude, duration, and onset velocity of esophageal body contractions, during 10 swallows of 5 mL of water. Significant analysis of variance differences (P < 0.05) are presented as mean ± standard deviation. Buspirone significantly increased mean distal esophageal wave amplitude (151 vs. 87 mmHg, P < 0.05) and duration (6.1 vs. 4.2 seconds, P < 0.05). Similarly, buspirone significantly increased mean LES resting pressure (26 vs. 21 mmHg, P < 0.05) and mean residual LES pressure (7.9 vs. 2 mmHg, P < 0.05), whereas reduced mean LES relaxation duration (7.2 vs. 8.0 seconds, P < 0.05) and mean distal onset velocity (7.6 vs. 14.7 cm/second, P < 0.05). Buspirone enhances esophageal peristalsis and LES function in healthy volunteers. Further study is warranted on the effects of buspirone on esophageal function and symptoms in patients with ineffective esophageal motility.