High-resolution Manometry Catheter Research Articles

Nasopharyngeal airway assistance improves esophageal intubation rates of high-resolution esophageal manometry catheters.

High-resolution esophageal manometry (HREM) is the gold standard test for esophageal motility disorders. Nasopharyngeal airway-assisted insertion of the HREM catheter is a suggested salvage technique for failure from the inability to pass the catheter through the upper esophageal sphincter (UES). It has not been demonstrated that the nasopharyngeal airway improves procedural success rate. Patients undergoing HREM between March 2019 and March 2023 were evaluated. Chart review was conducted for patient factors and procedural success rates before and after use of nasopharyngeal airway. Patients from March 2019 to May 2021 did not have nasopharyngeal airway available and were compared to patients from May 2021 to March 2023 who had the nasopharyngeal airway available. In total, 523 HREM studies were conducted; 234 occurred prior to nasopharyngeal airway availability, and 289 occurred with nasopharyngeal airway availability. There was no difference in HREM catheter UES intubation rates between periods when a nasopharyngeal airway attempt was considered procedural failure (85% vs. 85%, p = 0.9). Nasopharyngeal airway use after UES intubation failure lead to improved UES intubation rates (94% vs. 85%, p < 0.01). Thirty-six patients that failed HREM catheter UES intubation had the procedure reattempted with a nasopharyngeal airway, 30 (83%) of which were successful. The nasopharyngeal airway assisted catheter UES intubation for failures attributed to nasal pain and hypersensitivity, gagging, coughing, and pharyngeal coiling. Utilization of the nasopharyngeal airway increased rates of UES intubation. When HREM catheter placement through the UES fails, placement of a nasopharyngeal airway can be trialed to overcome patient procedural intolerance.

Rectal Sensory and Compliance Testing: A Method Comparison Study between High-Resolution Anorectal Manometry and Barostat Investigations.

Abnormal visceral perception and motor function are often observed in patients with fecal incontinence, evacuation disorders and irritable bowel syndrome. The international anorectal physiology working group has proposed a standardization for anorectal function assessment, where rectal sensitivity testing is performed using an elastic balloon attached to a high-resolution anorectal manometry (HRAM) catheter. Rectal compliance, another component of rectal function evaluation, is a pressure-volume relationship that refers to the rectum's ability to stretch and expand as it receives and holds fecal matter. There are no data available regarding the possibility of compliance testing using HRAM, although this is theoretically possible by correcting for the elastic balloon's intrinsic properties. The gold standard for measurement of visceral sensitivity and compliance is the rectal barostat, according to the procedure described by the European COST action GENIEUR group. Data on the agreement between the two different procedures are scarce. Hence, we performed a comparative study of the HRAM and barostat investigations in 26 healthy individuals. We hypothesized that by inflating the balloon before the examination, rectal compliance can be measured with HRAM investigations, and we examined correlations and levels of agreement between the methods. Our results demonstrate that assessing rectal compliance with HRAM is technically possible; however, a strong correlation with the rectal barostat was only observed at the maximum tolerable volume (Spearman's rho = 0.7, p = 0.02). We only found moderate correlations (Spearman's rho = 0.562, p = 0.019) for compliance according to the barostat methodology and for rectal sensibility testing (Spearman's rho = 0.57, p = 0.03 for maximum tolerable volume). Bland-Altman plots showed poor levels of agreement between the methods. We conclude that HRAM and the rectal barostat cannot be used interchangeably for compliance or sensitivity assessments. We suggest the development of a non-elastic balloon with a fixed size and shape to assess rectal sensory function and compliance in HRAM testing.

Esophageal Dilation in Patients with Achalasia Is a Predictive Factor for the Inability to Traverse the Esophagogastric Junction with a Manometric Catheter

Introduction: The insertion of a high-resolution manometry (HRM) catheter into the stomach is essential for accurate manometric diagnoses; however, it is impossible in some cases due to the inability to traverse the esophagogastric junction (EGJ). Predictive factors for these patients have not been investigated in detail, necessitating time-consuming and burdensome procedures for investigators and patients. Therefore, the present study investigated the percentage of and risk factors for failed intubation at the EGJ. Methods: We initially reviewed the medical charts of consecutive HRM procedures performed at our hospital between September 2018 and January 2023. Patient characteristics and the findings of endoscopy and esophagography (where available) were compared between successful and failed procedures. A multivariate logistic regression analysis was conducted to identify predictive factors for the inability to traverse the EGJ. We then validated the predictive factors identified by reviewing consecutive procedures performed between February 2023 and August 2023. Results: Among the 781 procedures performed, 55 (7.0%) failed due to the inability to traverse the EGJ. Achalasia was the most common disorder in these procedures. An older age and dilated esophagus of >34 mm were independent predictive factors for the inability to traverse the EGJ in patients with treatment-naïve achalasia. In the validation study, 7 out of 68 procedures (10.3%) failed due to the inability to traverse the EGJ. A flowchart using the findings of endoscopy and an esophageal diameter of >34 mm predicted the inability to traverse the EGJ with a sensitivity of 71.4% and specificity of 86.9%. Conclusion: Based on an esophageal diameter >34 mm and endoscopic findings, we predicted the inability to traverse the EGJ in more than 70% of patients. A multi-center prospective study is warranted in the future.

S2810 Management of a Retained High-Resolution Esophageal Manometry Catheter

S2810 Management of a Retained High-Resolution Esophageal Manometry Catheter

S574 Tooting Its Horn: Nasal Trumpet Improves Success of High-Resolution Esophageal Manometry Catheter Placement

S574 Tooting Its Horn: Nasal Trumpet Improves Success of High-Resolution Esophageal Manometry Catheter Placement

Esophageal Infusion of Menthol Does Not Affect Esophageal Motility in Patients with Gastroesophageal Reflux Disease.

Menthol is thought to trigger gastroesophageal reflux disease (GERD) symptoms by influencing esophageal peristalsis and lower esophageal sphincter (LES) function. We evaluated the effect of esophageal menthol infusion on esophageal motility and the LES in healthy volunteers and in patients with GERD. High resolution manometry (HRM) catheter with attached thin tube for menthol infusion was placed transnasally. Protocol which included baseline recording, 16 water swallows (5ml, 10ml, and 15ml) and the multiple rapid swallows was performed before and after esophageal infusion of menthol (3mM, 20min, 8ml/min). We evaluated the effect of this infusion on the HRM parameters of esophageal peristalsis (distal contractile integral, distal latency, contractile front velocity) and the lower esophageal sphincter (LES) barrier function (integrated relaxation pressure and the inspiratory augmentation of the LES). Simultaneously we evaluated the quality and intensity of the symptoms during the menthol infusion. Esophageal infusion of menthol did not appreciably affect HRM measurements characterizing esophageal peristalsis and LES pressure in healthy subjects (N = 13) or GERD patients (N = 11). The magnitude of the distal contractile integral (5ml) was changed neither in the healthy volunteers' group, (735 ± 127 vs. 814 ± 117mmHg, p = 0.5), nor in the GERD patients (295 ± 78 vs. 338 ± 96mmHg, p = 0.99). In healthy volunteers menthol did not change the inspiratory augmentation of the LES (8.67 ± 1.09 vs. 7.69 ± 0.96mmHg, p = 0.15) and neither did for GERD patients (8.8 ± 1.18 vs. 8.22 ± 0.91mmHg, p = 0.43). We observed no significant difference in any HRM parameter following menthol infusion, except for distal latency in 10ml swallows. By contrast, menthol infusion induced significantly more intense discomfort in GERD patient than in healthy volunteers. Our results suggest no significant temporal effect of menthol on the esophageal motility or LES function, neither in healthy volunteers, nor in GERD. Arguably, other mechanisms are responsible for menthol-related heartburn.

Comparison of electromyography, sound, bioimpedance, and high-resolution manometry for differentiating swallowing and vocalization events.

Non-invasive surface recording devices used for detecting swallowing events include electromyography (EMG), sound, and bioimpedance. However, to our knowledge there are no comparative studies in which these waveforms were recorded simultaneously. We assessed the accuracy and efficiency of high-resolution manometry (HRM) topography, EMG, sound, and bioimpedance waveforms, for identifying swallowing events. Six participants randomly performed saliva swallow or vocalization of "ah" 62 times. Pharyngeal pressure data were obtained using an HRM catheter. EMG, sound, and bioimpedance data were recorded using surface devices on the neck. Six examiners independently judged whether the four measurement tools indicated a saliva swallow or vocalization. Statistical analyses included the Cochrane's Q test with Bonferroni correction and the Fleiss' kappa coefficient. Classification accuracy was significantly different between the four measurement methods (P<0.001). The highest classification accuracy was for HRM topography (>99%), followed by sound and bioimpedance waveforms (98%), then EMG waveform (97%). The Fleiss' kappa value was highest for HRM topography, followed by bioimpedance, sound, and then EMG waveforms. Classification accuracy of the EMG waveform showed the greatest difference between certified otorhinolaryngologists (experienced examiners) and non-physicians (naive examiners). HRM, EMG, sound, and bioimpedance have fairly reliable discrimination capabilities for swallowing and non-swallowing events. User experience with EMG may increase identification and interrater reliability. Non-invasive sound, bioimpedance, and EMG are potential methods for counting swallowing events in screening for dysphagia, although further study is needed.

Do we need an extra dimension? A pilot study on the use of three-dimensional anorectal manometry in children with functional constipation.

Recently, a new high-definition (or three-dimensional "3D") high-resolution anorectal manometry (3D-ARM) catheter has been introduced. This catheter allows for a more detailed visualization of the anal canal. However, its clinical utility and tolerability in children with constipation are unknown. Our primary objective was to evaluate the agreement between findings from solid-state high-resolution anorectal manometry (HR-ARM) and 3D-ARM. Secondary objectives were to investigate if 3D-ARM has additional value over HR-ARM and to evaluate patient and provider experience. Prospective pilot study including children (8-18years of age) with functional constipation scheduled for anorectal manometry. Children underwent HR-ARM and 3D-ARM consecutively. We compared manometry results of both procedures and collected data on patient and provider experience via self-developed questionnaires. Data of ten patients were analyzed (60% female, median age 14.9years). In the majority of patients, ARMs were performed awake (n=8, 80%). In two patients, the recto-anal inhibitory reflex (RAIR) was visualized during HR-ARM but not during 3D-ARM. Anal canal resting pressures were significantly higher during 3D-ARM compared to HR-ARM (median 77mmHg [IQR 59-94] vs. 69mmHg [IQR 51-91], respectively, p=0.037). No significant anatomical or muscular abnormalities were visualized during the 3D-ARM. The majority of children identified the 3D-ARM as the more unpleasant (5/7 [71%]) and more painful procedure (6/7 [86%]) and therefore preferred the HR-ARM (4/7 [57%]). In our patient sample, 3D-ARM was associated with more discomfort without providing more useful information and even resulted in an inconsistent visualization of the RAIR.

Analysis of Intestinal Movements with Spatiotemporal Maps: Beyond Anatomy and Physiology.

Over 150years ago, methods for quantitative analysis of gastrointestinal motor patterns first appeared. Graphic representations of physiological variables were recorded with the kymograph after the mid-1800s. Changes in force or length of intestinal muscles could be quantified, however most recordings were limited to a single point along the digestive tract.In parallel, photography and cinematography with X-Rays visualised changes in intestinal shape, but were hard to quantify. More recently, the ability to record physiological events at many sites along the gut in combination with computer processing allowed construction of spatiotemporal maps. These included diameter maps (DMaps), constructed from video recordings of intestinal movements and pressure maps (PMaps), constructed using data from high-resolution manometry catheters. Combining different kinds of spatiotemporal maps revealed additional details about gut wall status, including compliance, which relates forces to changes in length. Plotting compliance values along the intestine enabled combined DPMaps to be constructed, which can distinguish active contractions and relaxations from passive changes. From combinations of spatiotemporal maps, it is possible to deduce the role of enteric circuits and pacemaker cells in the generation of complex motor patterns. Development and application of spatiotemporal methods to normal and abnormal motor patterns in animals and humans is ongoing, with further technical improvements arising from their combination with impedance manometry, magnetic resonance imaging, electrophysiology, and ultrasonography.

High-resolution colonic manometry interobserver analysis trial.

Colonic high-resolution manometry (HRM) is a novel, not widely used diagnostic method used in the final workup of chronic constipation before surgery. Since its introduction, different motor patterns have been defined. However, it remains to be established whether these patterns are easily and reproducibly identified by different investigators. The primary aim of this study was to determine agreement for motor pattern identification with HRM. To calculate the interobserver agreement (IOA), the Fleiss's kappa statistic for multiple observers was used. Seven participants analyzed 106 one-min time frames, derived from five measurements in healthy volunteers and five in patients with chronic constipation. The time frames were chosen to show a variety and combination of motor patterns consisting of short antegrade, short retrograde, cyclic anterograde, cyclic retrograde, long antegrade, long retrograde, slow retrograde motor pattern, high-amplitude propagating motor patterns, and pancolonic pressurizations. All of the measurements were performed with a solid-state colonic HRM catheter, comprising 40 pressure sensors spaced 2.5cm apart. A median of 10.25h (range 6-20) were required to analyze all time frames. High-amplitude propagating contractions achieved an almost perfect level of agreement (k=0.91). Several motor patterns achieved substantial agreement; these included the short antegrade (k=0.63), long antegrade (k=0.68), cyclic retrograde (k=0.70), slow retrograde motor pattern (k=0.80), and abdominal pressure or movement artifacts (k=0.67). Moderate agreement was found for short retrograde (k=0.57), cyclic anterograde (k=0.59), long retrograde motor patterns (k=0.59) and simultaneous pressure waves (k=0.59). For the majority of motor patterns, the overall IOA for colonic manometry was substantial or high. This high level of agreement supports the use of colonic manometry application in clinical and research settings. Harmonization has the potential to improve agreement for long anterograde motor patterns with high amplitudes and for mixed direction patterns.

Propagation patterns of jejunal motor activity measured by high-resolution water-perfused manometry.

The manometric diagnosis of severe intestinal dysmotility is performed at most institutions using catheters with 2-8 sensors 5-10cm apart. The recent application of high-resolution manometry catheters with closely spaced sensors to other gut segments has been highly successful. The objective of the present study was to determine the feasibility of a jejunal high-resolution manometry method and to carry out a descriptive analysis of normal jejunal motor function. A 36-channel high-resolution water-perfused manometry catheter (MMS-Laborie, Enschede, The Netherlands) was orally placed in the jejunum of 18 healthy subjects (10 men, eight women; 21-38 age range). Intestinal motility was recorded during 5h, 3 during fasting, and 2 after a 450kcal solid-liquid meal. Analysis of motility patterns was supported by computerized tools. All healthy subjects except one showed at least one complete migrating motor complex during the 3h fasting period. Phase III activity lasted 5±1min and migrated aborally at a velocity of 7±3cm/min. High-resolution spatial analysis showed that during phase III each individual contraction propagated rapidly (75±37cm/min) over a 32±10cm segment of the jejunum. During phase II, most contractile activity corresponded to propagated contractile events which increased in frequency from early to late phase II (0.5±0.9 vs 2.5±1.3 events/10min, respectively; p<0.001). After meal ingestion, non-propagated activity increased, whereas propagated events were less frequent than during late phase II. Jejunal motility analysis with high-resolution manometry identifies propagated contractile patterns which are not apparent with conventional manometric catheters.

The effect of an air purifier on aerosol generation measurements during clinical motility testing.

BackgroundAerosol spread is key to interpret the risk of viral contamination during clinical procedures such as esophageal high‐resolution manometry (HRM). Installing an air purifier seems a legitimate strategy, but this has recently been questioned.MethodsPatients undergoing an HRM procedure at the Leuven University Hospital were included in this clinical study. All subjects had to wear a surgical mask which was only lowered beneath the nose during the placement and removal of the nasogastric catheter. The number of aerosol particles was measured by a Lasair® II Particle Counter to obtain data about different particles sizes: 0.3; 0.5; 1.0; 3.0; 5.0; and 10.0 µm. Measurements were done immediately before the placement and the removal of the HRM catheter, and one and 5 min after. A portable air purifier with high‐efficiency particle air filters was installed in the hospital room.Key ResultsThirteen patients underwent a manometry examination. The amount of 0.3 µm‐sized particles was unaffected during the whole procedure. The larger particle sizes (1.0; 3.0; 5.0; and 10.0 µm) decreased when the catheter was positioned, but not 0.5 µm. During the HRM measurements itself, these numbers decreased further. Yet, 1 min after catheter removal a significant elevation of particles was seen, which did not recover within 5 min.Conclusions & InterferencesBased on this study, there is no evidence that filtration systems reduce aerosol particles properly during a clinical investigation.

Codeine induces increased resistance at the esophagogastric junction but has no effect on motility and bolus flow in the pharynx and upper esophageal sphincter in healthy volunteers: A randomized, double-blind, placebo-controlled, cross-over trial.

Chronic opioid use can induce esophageal dysfunction with symptoms resembling achalasia and a manometric pattern of esophagogastric junction-outflow obstruction (EGJ-OO). However, the effect of opioids in acute setting on pharyngeal function and esophageal body contractility has not been investigated. After positioning the high-resolution impedance manometry (HRiM) catheter, codeine (60mg) or placebo (glucose syrup) was infused intragastrically. Forty-five minutes post-infusion, participants received liquid, semi-solid, and solid boluses to assess esophageal and pharyngeal function. HRiM analysis was performed adhering to the Chicago classification v3.0. (CC v3.0). Pressure flow analysis (PFA) for the esophageal body and the pharynx was performed using the SwallowGateway™ online platform. Nineteen healthy volunteers (HV) [5 male; age 38.3] were included. After codeine administration, higher integrated relaxation pressure 4s values resulted in significantly reduced deglutitive EGJ relaxation and distal latency was significantly shorter. Distal contractility was similar in both conditions. Bolus flow resistance at the EGJ and distention pressures increased significantly after codeine infusion. Based on CC v3.0, acute infusion of codeine induced EGJ-OO in six HV (p=0.0003 vs. placebo). Codeine administration induced no significant alterations in any of the pharyngeal PFA metrics. In HV, acute administration of codeine increased bolus resistance at the EGJ secondary to induced incomplete EGJ relaxation leading to major motility disorders in a subset of subjects including EGJ-OO. However, an acute single dose of codeine did not affect motility or bolus flow in pharynx and UES. ClinicalTrials.gov number, NCT03784105.

S1892 An Interesting Case of Eosinophilic Esophagitis

INTRODUCTION: Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease with eosinophilic predominant inflammation. Symptoms include dysphagia, food impaction, and chest pain. Diagnosis is made via biopsy, requiring more than 15 eosinophils per high-power field. First line therapy is proton pump inhibitors (PPIs) along with dietary modifications and topical glucocorticoid to reduce inflammation. Untreated EoE can lead to fibrosis and strictures, requiring endoscopic dilatation. Given the consequences, it is important to recognize EoE, identify uncommon cofactors, and manage inflammation. We present a case of rumination syndrome found on manometry in a patient with unresolved EoE. CASE DESCRIPTION/METHODS: A 20-year-old male with Autism spectrum disorder, seasonal allergies, food allergies, asthma, and EoE presented for a second opinion for continued symptoms of dysphagia and post-prandial regurgitation to both solids and liquids along with a 10-pound weight loss while on a PPI 40 mg daily. He had been diagnosed with EoE with EGD and biopsies 2 years prior unresponsive to PPI. His PPI was advanced to 40 mg twice daily and he was started on a topical budesonide slurry. Because he continued to have significant symptoms an EGD was performed with high-resolution manometry catheter placement. EGD revealed mucosal changes consistent with EoE, confirmed via biopsy. Esophageal motility testing showed rumination pattern on multiple occasions during the post-prandial period. The patient was given a referral to behavioral health for rumination syndrome and his PPI and topical budesonide were continued. DISCUSSION: This case illustrates rumination syndrome as a possible cofactor in the management of EoE. Rumination syndrome is a functional gastrointestinal disorder consisting of cyclic regurgitation and ingestion of food matter. High-resolution manometry is the preferred test to diagnose rumination syndrome. Historically, rumination syndrome is considered a rare disorder, with scant systemic research, thus it is often missed or misdiagnosed due to lack of awareness. To the best of our knowledge, only two case reports have described the presentation of rumination syndrome in the setting of EoE. In both cases, as well as in our case, EoE was found to be histologically refractory to standard management in the setting of ongoing rumination. We find this an important case that highlights rumination syndrome may be present in refractory EoE and manometry with rumination protocol should be considered in these patients.

Intraoperative high-resolution esophageal manometry during peroral endoscopic myotomy

Peroral endoscopic myotomy is an accepted treatment of achalasia. Some of the treatment failures can be attributable to an insufficient length of the myotomy on the gastric side, because of a more technically challenging submucosal dissection. We assessed the feasibility and the impact of an intraoperative esophageal manometry during the peroral endoscopic myotomy procedure. A high-resolution manometry catheter was introduced through the nostril before the endoscope, and left in place during the peroral endoscopic myotomy procedure. The lower esophageal sphincter pressure was recorded throughout the peroral endoscopic myotomy. The myotomy was extended on the gastric side until the lower esophageal sphincter pressure dropped below 10 mmHg. We included 10 patients (mean age = 55 years old, 3 men) treated by peroral endoscopic myotomy for type I (3/10), type II (3/10), type III achalasia (3/10) or esophagogastric junction outflow obstruction (1/10). Manometric recording was possible in all patients. The median (IQR) lower esophageal sphincter resting pressure was 23 (17–37) mmHg before myotomy, 15 (13–19) mmHg at the end of the tunnel, and 7 (6–11) mmHg at the end of the myotomy. In 4 patients out of 10, the myotomy was extended on the base of the intraoperative manometry findings. High-resolution esophageal manometry is feasible during the peroral endoscopic myotomy procedure, and leads to increase the length of the gastric myotomy in 4 out of 10 patients. However, the cumbersome nature of intraoperative high-resolution manometry during peroral endoscopic myotomy and the high frequency of gastro-esophageal reflux disease after extended gastric myotomy suggest to limit this technique to selected patients refractory to a first myotomy.

Effects of phosphodiesterase-5 inhibitor sildenafil on esophageal secondary peristalsis: Studies with high-resolution manometry.

Secondary peristalsis contributes to the clearance of retained refluxate from the esophagus. Sildenafil, a phosphodiesterase-5 inhibitor, inhibits primary esophageal peristalsis, but its effects on secondary peristalsis remain unknown. This study sought to investigate whether sildenafil could influence physiological characteristics of secondary peristalsis by applying high-resolution manometry (HRM). Seventeen healthy volunteers (15 men and 2 women, aged 30.2±6.4years) underwent two HRM studies on separate days following the administration of either a placebo or 50mg of sildenafil in a random order. Both studies were performed using a water-perfused HRM catheter containing one air injection channel positioned in the mid-esophagus. Secondary peristalsis was stimulated by a rapid mid-esophageal injection of 10 or 20mL of air 1h after the administration of either the placebo or sildenafil. The frequency and distal contractile integral of secondary peristalsis were then compared. Complete secondary peristalsis triggered by the 20-mL air injection was more frequent than observed with the 10-mL air injection (P<0.001). The vigor of secondary peristalsis triggered by the injection of either volume of air was lower than that of primary peristalsis (P<0.001). Sildenafil significantly reduced the success rate (P≤0.001) and vigor (P<0.001) of secondary peristalsis relative to the effects of the placebo at both distension volumes. Secondary peristalsis can be successfully triggered by rapid air injection during HRM. Sildenafil reduces both the success rate and the vigor of secondary peristalsis, similar to that seen with primary peristalsis.

NORMAL VALUES OF ESOPHAGEAL HIGH-RESOLUTION MANOMETRY: A BRAZILIAN MULTICENTER STUDY.

The high-resolution manometry has been a significant advance in esophageal diagnostics. There are different types of catheter and systems devices to capture esophageal pressures that generate variable data related to Chicago Classification (CC) and consequently influence normal values results. There are not normative data for the 24-channel water-perfused high-resolution manometry system most used in Brazil with healthy volunteers in supine posture. To determine manometric esophageal normative values for a 24-channel water-perfused high-resolution manometry catheter in supine posture using healthy volunteers according to CC 3.0 parameters. A total of 92 volunteers with no gastrointestinal symptoms or medications affecting GI motility underwent esophageal high-resolution manometry by standard protocol. Age, gender and manometry parameters analyzed using Alacer software were collected. The median, range, and 5th and 95th percentiles (where applicable) were obtained for all high-resolution manometry metrics. Normal value percentiles were defined as 95th integrated relaxation pressure, 5th-100th distal contractile integral, and 5th distal latency. The mean age was 40.5±13.2 years. Our normative metrics were integrated relaxation pressure <16 mmHg and distal contractile integral (708-4111 mmHg.cm.s) distal latency was <6 s and peristaltic break size (>4 cm). For EGJ-CI the range 5th-95th was 21.7-86.9 mmHg.cm.s. This is the first report of normative data for the 24-channel water-perfused system in supine posture. It revealed higher integrated relaxation pressure and distal latency duration which suggest the need to change CC 3.0 cutoffs for this system. It is observed that there is a tendency that DCI >7000 mmHg.cm.s may represent the lower limit of hypercontractility, and when <700 mmHg.cm.s (<5% percentile) interpreted as ineffective esophageal motility or failcontraction. Also compared to Chicago 3.0, higher integrated relaxation pressure and duration of distal latency were found. We emphasize that these data must be confirmed by future studies.

Distinct patterns of myogenic motor activity identified in isolated human distal colon with high-resolution manometry.

Colonic high-resolution manometry (HRM) has been used to reveal discrete, propagating colonic motor patterns. To help determine mechanisms underlying these patterns, we used HRM to record contractile activity in human distal colon ex vivo. Surgically excised segments of descending (n=30) or sigmoid colon (n=4) were immersed in oxygenated Krebs solution at 36°C (n=34; 16 female; 67.6±12.4years; length: 24.7±3.5cm). Contractility was recorded by HRM catheters. After 30minutes of baseline recording, 0.3mM lidocaine and/or 1mM hexamethonium were applied. Ascending neural pathways were activated by electrical field stimulation (EFS; 10Hz, 0.5ms, 50V, 5-s duration) applied to the anal end before and after drug application. Spontaneous propagating contractions were recorded in all specimens (0.1-1.5 cycles/minute). Most contractions occurred synchronously across all recording sites. In five specimens, rhythmic antegrade contractions propagated acrossthe full length of the preparation. EFS evoked local contractions at the site of stimulation (latency: 5.5±2.4seconds) with greater amplitude than spontaneous contractions (EFS; 29.3±26.9 vs 12.1±14.8mm Hg; P=.02).Synchronous or retrograde propagating motor patterns followed EFS; 71% spanned the entire preparation length. Hexamethonium and lidocaine modestly and only temporarily inhibited spontaneous contractions, whereas TTX increased the frequency of contractile activity while inhibiting EFS-evoked contractions. Our study suggests that the propagated contractions recorded in the organ bath have a myogenic origin which can be regulated by neural input. Once activated at a local site, the contractions do not require the propulsion of fecal content to sustain long-distance propagation.

Pharyngeal Manometry in Pediatric Dysphagia Assessment

PurposeReliable measures to capture swallowing pathophysiology and outcomes from therapeutic interventions are needed in the pediatric setting. Therefore, this review presents the current best evidence for manometry investigation and its application in pediatric dysphagia. For oropharyngeal dysphagia assessment, videofluoroscopic swallow study is considered the gold standard, and fiberoptic endoscopic examination of swallowing is also employed in some settings. In clinical practice, both tests mostly rely on qualitative interpretation of image data and have variable reliability to detect pathophysiology.ConclusionAcknowledging that swallowing is a pressure-driven event, the role of manometry is now being considered as an objective, nonradiological technique that can be performed as an adjunct to other clinical swallow evaluations. The latest high-resolution manometry catheter technologies are miniaturized and simple to use, enhancing their potential application in pediatric clinical and research contexts.

Detailed measurements of oesophageal pressure during mechanical ventilation with an advanced high-resolution manometry catheter

BackgroundOesophageal pressure (PES) is used for calculation of lung and chest wall mechanics and transpulmonary pressure during mechanical ventilation. Measurements performed with a balloon catheter are suggested as a basis for setting the ventilator; however, measurements are affected by several factors. High-resolution manometry (HRM) simultaneously measures pressures at every centimetre in the whole oesophagus and thereby provides extended information about oesophageal pressure. The aim of the present study was to evaluate the factors affecting oesophageal pressure using HRM.MethodsOesophageal pressure was measured using a high-resolution manometry catheter in 20 mechanically ventilated patients (15 in the ICU and 5 in the OR). Different PEEP levels and different sizes of tidal volume were applied while pressures were measured continuously. In 10 patients, oesophageal pressure was also measured using a conventional balloon catheter for comparison. A retrospective analysis of oesophageal pressure measured with HRM in supine and sitting positions in 17 awake spontaneously breathing patients is also included.ResultsHRM showed large variations in end-expiratory PES (PESEE) and tidal changes in PES (ΔPES) along the oesophagus. Mean intra-individual difference between the minimum and maximum end-expiratory oesophageal pressure (PESEE at baseline PEEP) and tidal variations in oesophageal pressure (ΔPES at tidal volume 6 ml/kg) recorded by HRM in the different sections of the oesophagus was 23.7 (7.9) cmH2O and 7.6 (3.9) cmH2O respectively. Oesophageal pressures were affected by tidal volume, level of PEEP, part of the oesophagus included and patient positioning. HRM identified simultaneous increases and decreases in PES within a majority of individual patients. Compared to sitting position, supine position increased PESEE (mean difference 12.3 cmH2O), pressure variation within individual patients and cardiac artefacts. The pressure measured with a balloon catheter did not correspond to the average pressure measured with HRM within the same part of the oesophagus.ConclusionsThe intra-individual variability in PESEE and ΔPES is substantial, and as a result, the balloon on the conventional catheter is affected by many different pressures along its length. Oesophageal pressures are not only affected by lung and chest wall mechanics but are a complex product of many factors, which is not obvious during conventional measurements. For correct calculations of transpulmonary pressure, factors influencing oesophageal pressures need to be known. HRM, which is available at many hospitals, can be used to increase the knowledge concerning these factors.Trial registrationClinicalTrials.gov, NCT02901158