High-resolution Manometry Studies Research Articles

Achalasia: A New Clinically Relevant Classification by High-Resolution Manometry

Although the diagnosis of achalasia hinges on demonstrating impaired esophagogastric junction (EGJ) relaxation and aperistalsis, 3 distinct patterns of aperistalsis are discernable with high-resolution manometry (HRM). This study aimed to compare the clinical characteristics and treatment response of these 3 subtypes. One thousand clinical HRM studies were reviewed, and 213 patients with impaired EGJ relaxation were identified. These were categorized into 4 groups: achalasia with minimal esophageal pressurization (type I, classic), achalasia with esophageal compression (type II), achalasia with spasm (type III), and functional obstruction with some preserved peristalsis. Clinical and manometric variables including treatment response were compared among the 3 achalasia subtypes. Logistic regression analysis was performed using treatment success as the dichotomous dependent variable controlling for independent manometric and clinical variables. Ninety-nine patients were newly diagnosed with achalasia (21 type I, 49 type II, 29 type III), and 83 of these had sufficient follow-up to analyze treatment response. Type II patients were significantly more likely to respond to any therapy (BoTox [71%], pneumatic dilation [91%], or Heller myotomy [100%]) than type I (56% overall) or type III (29% overall) patients. Logistic regression analysis found type II to be a predictor of positive treatment response, whereas type III and pretreatment esophageal dilatation were predictive of negative treatment response. Achalasia can be categorized into 3 subtypes that are distinct in terms of their responsiveness to medical or surgical therapies. Utilizing these subclassifications would likely strengthen future prospective studies of treatment efficacy in achalasia.

Novas técnicas ambulatoriais para avaliação da motilidade esofágica e sua aplicação no estudo do megaesôfago

Brazilian surgeons deal routinely with esophageal motility disorders, because achalasia is highly prevalent in Brazil due to Chagas' disease. In the last years new technologies for the evaluation of esophageal motility became available. High resolution manometry and the combination of barometric parameters and intraluminal impedance are the new frontiers on this topic. The authors reviewed current, national and international, literature about achalasia with multichannel intraluminal impedance and high resolution manometry studies. The new technologies described are promising, however few studies have been published and further studies are still expected for achalasia patients.

Classifying Esophageal Motility by Pressure Topography Characteristics: A Study of 400 Patients and 75 Controls

This study aimed to devise a scheme for the systematic analysis of esophageal high-resolution manometry (HRM) studies displayed using topographic plotting. A total of 400 patients and 75 control subjects were studied with a 36-channel HRM assembly. Studies were analyzed in a stepwise fashion for: (a) the adequacy of deglutitive esophagogastric junction (EGJ) relaxation, (b) the presence and propagation characteristics of distal esophageal persitalsis, and (c) an integral of the magnitude and span of the distal esophageal contraction. Two strengths of pressure topography plots compared to conventional manometric recordings were: (a) the ability to delineate the spatial limits, vigor, and integrity of individual contractile segments along the esophagus, and (b) the ability to distinguish between loci of compartmentalized intraesophageal pressurization and rapidly propagated contractions. Making these distinctions objectified the identification of distal esophageal spasm (DES), vigorous achalasia, functional obstruction, and nutcracker esophagus subtypes. Applying these distinctions made the diagnosis of spastic disorders quite rare: (a) DES in 1.5% patients, (b) vigorous achalasia in 1.5%, and (c) a newly defined entity, spastic nutcracker, in 1.5%. We developed a systematic approach to analyzing esophageal motility using HRM and pressure topography plots. The resultant scheme is consistent with conventional classifications with the caveats that: (a) hypercontractile conditions are more specifically defined, (b) distinctions are made between rapidly propagated contractions and compartmentalized esophageal pressurization, and (c) there is no "nonspecific esophageal motor disorder" classification. We expect that pressure topography analysis, with its well-defined functional implications, will prove valuable in the clinical management of esophageal motility disorders.

Impaired deglutitive EGJ relaxation in clinical esophageal manometry: a quantitative analysis of 400 patients and 75 controls

Assessing deglutitive esophagogastric junction (EGJ) relaxation is an essential focus of clinical manometry. Our aim was to apply automated algorithmic analyses to high-resolution manometry (HRM) studies to ascertain the optimal method for discriminating normal from abnormal deglutitive EGJ relaxation. All 473 subjects (73 controls) were studied with a 36-channel solid-state HRM assembly during water swallows. Patients were classified as: 1) achalasia, 2) postfundoplication, 3) nonachalasia with normal deglutitive EGJ relaxation, or 4) functional obstruction (preserved peristalsis with incomplete EGJ relaxation). Automated computer programs assessed the adequacy of EGJ relaxation by using progressively complex analysis routines to compensate for esophageal shortening, crural diaphragm contraction, and catheter movement, all potential confounders. The single-sensor method of assessing EGJ relaxation had a sensitivity of only 52% for detecting achalasia. Of the automated HRM analysis paradigms tested, the 4-s integrated relaxation pressure using a cutoff of 15 mmHg performed optimally with 98% sensitivity and 96% specificity in the detection of achalasia. We also identified a heterogeneous group of 26 patients with functional EGJ obstruction attributed to variant achalasia and other diverse pathology. Although further clinical experience will ultimately judge, it is our expectation that applying rigorous methodology such as described herein to the analysis of HRM studies will improve the consistency in the interpretation of clinical manometry and prove useful in guiding clinical management.

Quelles explorations spécialisées pour les muscles respiratoires : de la stimulation magnétique à l’imagerie

The purpose of this study was to investigate the function and importance of infrahyoid muscles with the suprahyoid muscles during swallowing, and to investigate swallowing sequences using kinematic analysis, high-resolution manometry (HRM) and electromyography (EMG). As a preliminary study, ten healthy subjects were prospectively enrolled. A needle EMG evaluated the onset latency, peak latency and duration of the suprahyoid and infrahyoid muscles. HRM measured the time intervals among the velopharynx, tongue base, and upper esophageal sphincter. We also evaluated hyoid motion using an automated kinematic analysis software® (AKAS). All of these parameters were synchronized with a tilting motion of the epiglottis. In the EMG analysis, the activations of the suprahyoid muscles developed about 300 ms earlier than that of the infrahyoid muscles. There was a significant relationship between the differences of suprahyoid and infrahyoid muscles’ latency and total duration of the hyoid motion (p < 0.05). The interval time of anterior hyoid motion has a significant correlation in the upper esophageal sphincter (UES) opening time. In conclusions, the functions of the infrahyoid muscles are also as important as that of the suprahyoid muscles for prolonged laryngeal elevation and UES opening. Moreover, kinematic analysis of videofluoroscopic swallowing study (VFSS) and HRM studies could reflect results of needle EMG study and replace EMG study.

Gastric flow and mixing studied using computer simulation

The fed human stomach displays regular peristaltic contraction waves that originate in the proximal antrum and propagate to the pylorus. High-resolution concurrent manometry and magnetic resonance imaging (MRI) studies of the stomach suggest a primary function of antral contraction wave (ACW) activity unrelated to gastric emptying. Detailed evaluation is difficult, however, in vivo. Here we analyse the role of ACW activity on intragastric fluid motions, pressure, and mixing with computer simulation. A two-dimensional computer model of the stomach was developed with the 'lattice-Boltzmann' numerical method from the laws of physics, and stomach geometry modelled from MRI. Time changes in gastric volume were specified to match global physiological rates of nutrient liquid emptying. The simulations predicted two basic fluid motions: retrograde 'jets' through ACWs, and circulatory flow between ACWs, both of which contribute to mixing. A well-defined 'zone of mixing', confined to the antrum, was created by the ACWs, with mixing motions enhanced by multiple and narrower ACWs. The simulations also predicted contraction-induced peristaltic pressure waves in the distal antrum consistent with manometric measurements, but with a much lower pressure amplitude than manometric data, indicating that manometric pressure amplitudes reflect direct contact of the catheter with the gastric wall. We conclude that the ACWs are central to gastric mixing, and may also play an indirect role in gastric emptying through local alterations in common cavity pressure.