Transmitted cardiovascular pulsations on high resolution esophageal impedance manometry, and their significance in dysphagia

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.

Dysphagia lusoria: utility of high-resolution impedance manometry to identify true disease

Dysphagia lusoria is a rare cause of dysphagia due to impingement of the esophagus by an aberrant right subclavian artery. Although most remain asymptomatic, this aberrant vessel can lead to progressive dysphagia in childhood or even later in life as a result of arteriosclerotic burden and attenuation of esophageal compliance that led to esophageal compression. We present a 56-year-old man with a 3-year history of progressively worsening dysphagia to solids and liquids and globus sensation. Videofluoroscopic swallowing study (modified barium esophagram) and barium esophagram showed delayed barium tablet transit in the upper esophagus and focal smooth narrowing of the upper esophagus caused by external compression, respectively. Computed tomography imaging demonstrated external compression of proximal esophagus from an aberrant right subclavian artery with high atherosclerotic burden. In addition, high-resolution impedance manometry (HRiM) revealed a striking high-pressure pulsatile vascular band in the proximal esophagus (108 mmHg) associated with poor bolus transit, demonstrating the utility of HRiM in strengthening the diagnoses of true dysphagia lusoria.

Distal contractile integral measurement and vascular compression in the esophagus: a problem unsolved?

BACKGROUND

Distal contractile integral (DCI) is influenced by factors other than esophageal smooth muscle contractility, such as intrabolus pressure and vascular and respiratory movements' artifacts. We aimed to determine the size of the contribution of pressures generated by vascular compression on the esophagus to the DCI measured in HRM recordings in symptomatic patients.

METHODS

HRM manometry recordings obtained from 383 subjects referred to the GI motility laboratory at a tertiary center (2012-2016) were evaluated by visual inspection for evidence of strong vascular compression (SVC) of the esophagus. Clinical, demographic, manometric, and serologic data for Chagas disease were obtained. Subjects were classified, respectively, as asymptomatics (ASYM) or symptomatics (SYMP). DCI and SVC-DCI were measured, and the SVC-DCI/DCI ratio was expressed as a percentage and the difference between DCI and SVC-DCI (neat-DCI) was calculated. DCI, SVC-DCI, SVC-DCI/DCI % and neat-DCI from SYMP and ASYM were compared.

RESULTS

SVC was conspicuous in 42 of 383 subjects (11%). In 33 subjects, SVC was detected only in supine position. SVC was localized in middle esophagus in 21 subjects (50%), in distal esophagus in 12 subjects (29%) and in both regions in 9 subjects (21%). In 9 subjects, SVC vanished from the swallowing window analysis (21%).

CONCLUSIONS

SVC is a common finding in esophageal HRM study, particularly in the supine position. Occasionally, its contribution to DCI value is sufficiently great to masquerade esophageal hypocontractility. Different manometric protocols may be required in patients with SVC.

The Challenges of Esaphagogastric Junction Outflow Obstruction, Is It Really a Diagnosis? Creating a Systematic Clinical Approach for EGJOO

Esophagogastric junction outflow obstruction (EGJOO) is currently diagnosed according to the Chicago Classification V3 by an elevated median integrated relaxation pressure on high resolution manometry. However, EGJOO may not be an accurate diagnosis, as it may be based on abnormal IRP from an artifact, affected by narcotics, an achalasia variant, or a mechanical cause of obstruction. This heterogenous diagnosis can often lead to unnecessary testing and treatment. The purpose of this study is to develop a stepwise clinical management protocol on how to evaluate EGJOO. Motility studies were reviewed for the last 2 years and 39 patients were diagnosed with EGJOO. Clinical information was reviewed, and patients were classified into six stepwise categories to explain an elevated IRP resulting in EGJOO diagnosis: (1) underlying catheter artifact (2) opioid use (3) achalasia variant (4) jackhammer esophagus with obstruction (5) missed esophageal lesion (ex. Schatzki ring, EOE) and (6) extrinsic compression. 40% (n = 14) of patients with elevated IRP were due to an underlying catheter artifact. 8.6% (n = 3) were due to opioid use. 8.6% (n = 3) were due to achalasia variant. 31.4% (n = 11) were due to jackhammer esophagus with obstruction. 5.7% (n = 2) were due to missed esophageal lesion. 5.7% (n = 2) were due to external compression by cardiomegaly and aortic aneurism. EGJOO is not a diagnostic end point, but a heterogenous category with multiple underlying etiologies. We believe the use of a stepwise approach to these patients can help avoid further unnecessary testing.

Vascular pressure bands on high-resolution esophageal manometry with impedance studies

Horizontal pressure bands on high-resolution esophageal manometry with impedance (HREMI) tracings are often seen and thought to be due to cardiovascular structures compressing the esophagus. The aim of this study was to determine the prevalence and location of vascular pressure bands on HREMI studies and correlate these pressure bands to bolus clearance. HREMI studies in supine and upright positions from patients and normal volunteers were reviewed. Pressure bands were defined as bands of horizontal pressure greater than the 20 mmHg isobaric contour. Each swallow was reviewed with impedance to determine if bolus transit was impaired by the band. 38.6% of 251 patients and 36.4% of 11 normal controls had a pressure band present. There were a greater number of bands in supine versus upright position (patients: 130 vs. 25, P < 0.001 and controls: 6 vs. 1). Patients with pressure bands had similar demographics (age, gender, BMI) compared to those without. Average distal contractile integral of bands was greater in supine compared to upright (133 ± 201 vs. 60 ± 148 mmHg cm s, P < 0.05). Bands were commonly located clustered at 46 and 72% of esophageal length. Bolus transit was impaired by bands in 20.4% of supine and 14.0% of upright swallows. Vascular pressure bands can have a prominent appearance on HREMI studies, present in, being more prevalent and having greater pressure in the supine than the upright position. These vascular bands, when present, may impair esophageal transit.