Water-perfused esophageal high-resolution manometry: normal values and validation

A prediction model of abnormal acid reflux in gastroesophageal reflux disease

BACKGROUND AND AIM

The measurement of esophageal acid exposure time (AET) using combined multichannel intraluminal impedance-pH (MII-pH) tests is the gold standard for diagnosing gastroesophageal reflux disease (GERD). However, this catheter-based 24-h test can cause considerable patient discomfort. Our aim is to identify factors affecting AET and to develop a scoring model for predicting AET abnormalities before conducting the MII-pH test.

METHODS

Of the 366 patients who underwent MII-pH test at two facilities in Japan and Vietnam, 255 patients who also had esophagogastroduodenoscopy and high-resolution manometry were included in this study. Logistic regression analysis was conducted using risk factors for AET > 6% identified from a derivation cohort (n = 109). A scoring system predicting AET > 6% was then constructed and externally validated with a separate cohort (n = 146).

RESULTS

Three variables were derived from the prediction model: male gender, Hill grades III-IV, and weak mean distal contractile integrals. Based on these scores, patients were classified into low (0 point), intermediate (1-3 points), and high (4 points) risk groups. The probabilities of having an AET > 6% were 6%, 34%, and 100% for these groups, respectively. A score of < 1 excluded patients with abnormal AET, with a negative predictive value of 93.8% in the derivation cohort and 80.0% in the validation cohort.

CONCLUSIONS

We derived and externally validated a prediction model for abnormal AET. This system could assist in guiding the appropriate treatment strategies for GERD.

How provocative tests in addition to wet swallows during high-resolution manometry can direct clinical management

PURPOSE OF REVIEW

Provocative tests have been advocated to address limitations of high-resolution manometry (HRM) with wet swallows. We describe the commonly used provocative manometric manoeuvres [rapid drink challenge (RDC), multiple rapid swallows (MRS), solid swallows and the solid test meal (STM)], compare their diagnostic yield and accuracy to wet swallows, and outline their role in directing clinical management.

RECENT FINDINGS

Provocative testing with RDC and STM identifies a proportion of achalasia cases missed by standard testing, and RDC can play a similar role to radiology in the evaluation of treatment response. In EGJOO, provocative testing with RDC and STM not only increase the diagnostic yield, but can also help differentiate between spurious cases and those representing true outflow obstruction likely to respond to achalasia-type therapies. MRS and STM can help determine the clinical relevance (or otherwise) of ineffective oesophageal motility, and in this setting, MRS may predict the likelihood of postfundoplication dysphagia. RDC and STM can help identify cases of postfundoplication dysphagia more likely to respond to dilatation.

SUMMARY

Provocative testing has been shown to increase diagnostic yield of HRM, clarify inconclusive diagnoses, allows corroboration of dysmotility with patient symptoms and helps direct clinical management.

Elevated average maximum intrabolus pressure on high-resolution manometry is associated with esophageal dysmotility and delayed esophageal emptying on timed barium esophagram

BACKGROUND

Intrabolus pressure (IBP) recorded by high-resolution manometry (HRM) portrays the compartmentalized force on a bolus during esophageal peristalsis. HRM may be a reliable screening tool for esophageal dysmotility in patients with elevated average maximum IBP (AM-IBP). Timed barium esophagram (TBE) is a validated measure of esophageal emptying disorders, such as esophagogastric junction outflow obstruction and achalasia. This study aimed to determine if an elevated AM-IBP correlates with esophageal dysmotility on HRM and/or delayed esophageal emptying on TBE.

METHODS

A retrospective analysis of all HRM (unweighted sample n = 155) performed at a tertiary referral center from 09/2015-03/2017 yielded a case group (n = 114) with abnormal AM-IBP and a control group (n = 41) with a normal AM-IBP (pressure < 17 mmHg) as consistent with Chicago Classification 3. All patients received a standardized TBE, with abnormalities classified as greater than 1 cm of retained residual liquid barium in the esophagus at 1 and 5 min or as tablet retention after 5 min.

RESULTS

AM-IBP was significantly related to liquid barium retention (p = 0.003) and tablet arrest on timed barium esophagram (p = 0.011). A logistic regression model correctly predicted tablet arrest in 63% of cases. Tablet arrest on AM-IBP correlated with an optimal prediction point at 20.1 mmHg on HRM. Patients with elevated AM-IBP were more likely to have underlying esophageal dysmotility (95.6% vs. 70.7% respectively; p < 0.001), particularly esophagogastric junction outflow obstruction disorders. Elevated AM-IBP was associated with incomplete liquid bolus transit on impedance analysis (p = 0.002).

CONCLUSIONS

Our findings demonstrate that an elevated AM-IBP is associated with abnormal TBE findings of esophageal tablet retention and/or bolus stasis. An abnormal AM-IBP (greater than 20.1 mm Hg) was associated with a higher probability of retaining liquid bolus or barium tablet arrest on TBE and esophageal dysmotility on HRM. This finding supports the recent incorporation of IBP in Chicago Classification v4.0.

Pneumatic dilation for persistent dysphagia after antireflux surgery, a multicentre single-blind randomised sham-controlled clinical trial

OBJECTIVE

There is no evidence-based treatment for persistent dysphagia after laparoscopic fundoplication. The aim of this study was to evaluate the effect of pneumatic dilation on persistent dysphagia after laparoscopic fundoplication.

DESIGN

We performed a multicentre, single-blind, randomised sham-controlled trial of patients with persistent dysphagia (>3 months) after laparoscopic fundoplication. Patients with an Eckardt symptom score ≥4 were randomly assigned to pneumatic dilation (PD) using a 35 mm balloon or sham dilation. Primary outcome was treatment success, defined as an Eckardt score <4 and a minimal reduction of 2 points in the Eckardt score after 30 days. Secondary outcomes included change in stasis on timed barium oesophagogram, change in high-resolution manometry parameters and questionnaires on quality of life, reflux and dysphagia symptoms.

RESULTS

Forty-two patients were randomised. In the intention-to-treat analysis, the success rates of PD (7/21 patients (33%)) and sham dilation (8/21 patients (38%)) were similar after 30 days (risk difference -4.7% (95% CI (-33.7% to 24.2%) p=0.747). There was no significant difference in change of stasis on the timed barium oesophagogram after 2 min (PD vs sham: median 0.0 cm, p25-p75 range 0.0-4.3 cm vs median 0.0 cm, p25-p75 range 0.0-0.0; p=0.122) or change in lower oesophageal sphincter relaxation pressure (PD vs sham: 10.54±6.25 vs 14.60±6.17 mm Hg; p=0.052). Quality of life, reflux and dysphagia symptoms were not significantly different between the two groups.

CONCLUSION

Pneumatic dilation with a 35 mm balloon is not superior to sham dilation for the treatment of persistent dysphagia after fundoplication.

Variations in Clinical Practice of Esophageal High-resolution Manometry: A Nationwide Survey

Background/Aims

Esophageal high-resolution manometry (HRM) enables the comprehensive evaluation of the esophageal motor function. However, protocols are not uniform and clinical practices vary widely among institutions. This study aims to understand the current HRM practice in Korea.

Methods

The survey was sent via email through the Korean Society of Neurogastroenterology and Motility. The questions covered descriptive information, preparation, techniques, analysis, and reporting of esophageal HRM.

Results

The survey was completed in 32 (74.4%) out of 43 centers, including 24 tertiary and 8 secondary referral centers. Of the 32 centers, 25 (78.1%) performed HRM in a sitting position, while 7 centers (21.9%) reported performing HRM in a supine position. All the centers utilized single wet swallows as a standard, but the volume, frequency, and interval between swallows varied widely. Sixteen centers (50.0%) applied adjunctive tests, including multiple rapid swallows (n = 16) and rapid drink challenges (n = 9). Parameters assessed and documented in the report were similar. In addition to the assessment of the esophagogastric junction and esophageal body, 27 centers (84.8%) and 18 centers (56.3%) included measurements for the upper esophageal sphincter and the pharynx, respectively, in the HRM protocol.

Conclusions

We found a variation in the available HRM practice among centers, even though they broadly agreed in the data analysis. Efforts are needed to develop a standardized protocol for HRM measurement.

European Society for Neurogastroenterology and Motility (ESNM) recommendations for the use of high-resolution manometry of the esophagus

BACKGROUND

Several patients in gastroenterology practice present with esophageal symptoms, and in case of normal endoscopy with biopsies, high-resolution manometry (HRM) is often the next step. Our aim was to develop a European consensus on the clinical application of esophageal HRM, to offer the clinician guidance in selecting patients for HRM and using its results to optimize clinical outcome.

METHODS

A Delphi consensus was initiated with 38 multidisciplinary experts from 16 European countries who conducted a literature summary and voting process on 71 statements. Quality of evidence was evaluated using grading of recommendations assessment, development, and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 33 statements.

RESULTS

The process generated guidance on when to consider esophageal HRM, how to perform it, and how to generate the report. The Delphi process also identified several areas of uncertainty, such as the choice of catheters, the duration of fasting and the position in which HRM is performed, but recommended to perform at least 10 5-ml swallows in supine position for each study. Postprandial combined HRM impedance is considered useful for diagnosing rumination. There is a large lack of consensus on treatment implications of HRM findings, which is probably the single area requiring future targeted research.

CONCLUSIONS AND INFERENCES

A multinational and multidisciplinary group of European experts summarized the current state of consensus on technical aspects, indications, performance, analysis, diagnosis, and therapeutic implications of esophageal HRM.

Pharyngeal and upper esophageal sphincter motor dynamics during swallow in children

BACKGROUND

Motor abnormalities of pharyngeal contraction or upper esophageal sphincter (UES) relaxation can lead to swallowing problems.

METHODS

We reviewed high-resolution esophageal manometry of children ≤18 years and classified into two groups based on the results of videofluoroscopic study of swallow (VFSS), as normal or abnormal. The UES metrics (integrated relaxation pressure [IRP], resting pressure [URP], and nadir pressure [UNP]), as well as peak pharyngeal pressure (velopharyngeal and meso-hypopharyngeal), were analyzed.

RESULTS

UES metrics: There were 142 and 19 subjects in the normal and abnormal groups, respectively. In the normal group, the median UES-IRP at 0.2, 0.4, 0.6, 0.8 seconds, URP, and UNP were 1.0, 4.0, 11.0, 18.0, 53.5, and -1.0 mm Hg while in the abnormal group were 10.0, 13.0, 21.0, 25.5, 47.0, and 8.0 mm Hg. The UES-IRP at 0.2, 0.4, 0.6 seconds, and UNP was significantly higher in the abnormal group. Pharyngeal metrics: We included 58 subjects in normal and 10 subjects in the abnormal group. The median of peak velopharyngeal and meso-hypopharyngeal pressures were lower in the abnormal group; 188.50 vs 210.50, P = .185 and 110.00 vs 144.75 mm Hg, P = .065.

CONCLUSIONS AND INFERENCES

The UES-IRP was lower than adults, URP was higher than preterm but less than adults, and UNP was lower than neonates but similar to adults. The pharyngeal pressures were higher than those reported for neonates and adults. Our data indicate that motor dynamics of swallowing may change from neonates to adulthood and reflect a maturational process. The subjects with abnormal VFSS had significantly higher UES-IRP and UNP compared to normal VFSS.

VALIDATION OF A NEW WATER-PERFUSED HIGH-RESOLUTION MANOMETRY SYSTEM

Background:

High-resolution manometry is more costly but clinically superior to conventional manometry. Water-perfused systems may decrease costs, but it is unclear if they are as reliable as solid-state systems, and reference values are interchangeable.

Aim:

To validate normal values for a new water-perfusion high-resolution manometry system.

Methods:

Normative values for a 24-sensors water perfused high-resolution manometry system were validated by studying 225 individuals who underwent high resolution manometry for clinical complaints. Patients were divided in four groups: group 1 - gastroesophageal reflux disease; group 2 - achalasia; group 3 - systemic diseases with possible esophageal manifestation; and group 4 - dysphagia.

Results:

In group 1, a hypotonic lower esophageal sphincter was found in 49% of individuals with positive 24 h pH monitoring, and in 28% in pH-negative individuals. In groups 2 and 3, aperistalsis was found in all individuals. In group 4, only one patient (14%) had normal high-resolution manometry.

Conclusions:

The normal values determined for this low-cost water-perfused HRM system with unique peristaltic pump and helicoidal sensor distribution are discriminatory of most abnormalities of esophageal motility seen in clinical practice.

Normative reference values for esophageal high-resolution manometry in healthy adults: A systematic review

Establishing normative values of high-resolution esophageal manometry is necessary for accurate interpretation and comparison of measurements. In this systematic review, we aimed to summarize normal values for different esophageal high-resolution manometry systems. Moreover, we assessed the effect of body position, bolus consistency, and provocative maneuvers on these normative thresholds. We searched Medline, Embase, and the Cochrane Library from January 1st, 2006, to January 20th, 2020, for studies that reported normative data of high-resolution manometry in healthy volunteers. We assessed methodological quality of the included studies and planned a descriptive analysis. We analyzed data from 54 articles describing normative thresholds in high-resolution manometry using solid-state or water-perfused systems. Forty-six studies performed the manometry study in the supine position with liquid swallows, whereas sixteen studies described normative values in the upright position. Twelve studies assessed normative values for different bolus consistencies, and nine studies evaluated different provocative maneuvers. There is a considerable variety of normative values for esophageal high-resolution manometry depending on the equipment used and the protocols performed to obtain measurements. This should be taken into account when evaluating measurements in clinical practice and when comparing results of published research studies.

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

ABSTRACT BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

British Society of Gastroenterology guidelines for oesophageal manometry and oesophageal reflux monitoring

These guidelines on oesophageal manometry and gastro-oesophageal reflux monitoring supersede those produced in 2006. Since 2006 there have been significant technological advances, in particular, the development of high resolution manometry (HRM) and oesophageal impedance monitoring. The guidelines were developed by a guideline development group of patients and representatives of all the relevant professional groups using the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool. A systematic literature search was performed and the GRADE (Grading of Recommendations Assessment, Development and Evaluation) tool was used to evaluate the quality of evidence and decide on the strength of the recommendations made. Key strong recommendations are made regarding the benefit of: (i) HRM over standard manometry in the investigation of dysphagia and, in particular, in characterising achalasia, (ii) adjunctive testing with larger volumes of water or solids during HRM, (iii) oesophageal manometry prior to antireflux surgery, (iv) pH/impedance monitoring in patients with reflux symptoms not responding to high dose proton pump inhibitors and (v) pH monitoring in all patients with reflux symptoms responsive to proton pump inhibitors in whom surgery is planned, but combined pH/impedance monitoring in those not responsive to proton pump inhibitors in whom surgery is planned. This work has been endorsed by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG) under the auspices of the oesophageal section of the BSG.

The importance of pH reflux monitoring test for the management of low-grade esophagitis in Chinese patients

BACKGROUND AND AIMS

Low-grade esophagitis (grade A and B) are no longer believed as confirmatory evidence of gastroesophageal reflux disease, but there were no data about the association of low-grade esophagitis with pathological acid reflux (PAR) in China. This study aimed to summarize the proportion of PAR in the patients with low-grade esophagitis and to explore the differential factors between low-grade esophagitis patients with and without PAR.

METHODS

Database of the patients accepted 24-hour pH monitoring in the motility laboratory of a tertiary center was retrospectively searched, and the patients were diagnosed as low-grade esophagitis before the procedure was recruited. The demographics, symptoms and high-resolution manometry and pH monitoring parameters were compared between the patients with pathological and physiological acid reflux and between patients with grade A and B esophagitis.

RESULTS

About 24% of grade A and 55% of grade B esophagitis patients had pathological acid reflux. The demographics, symptoms, and almost all high-resolution manometry findings were similar in patients with pathological and physiological acid reflux. About two-thirds of the participants with physiological acid reflux reported symptom improvement after PPI administration. All participants with PPI-resistant symptoms were with physiological acid reflux.

CONCLUSION

The proportion of PAR in low-grade esophagitis is not high. For patients with low-grade esophagitis in China, especially the patients with grade A esophagitis, regardless of symptom change, reflux monitoring is possibly needed for the patients whose esophageal mucosa break is not improved after 8 weeks of PPI treatment.

Pharmacologic interrogation of patients with esophagogastric junction outflow obstruction using amyl nitrite

BACKGROUND

The Chicago Classification of esophageal motility includes a group of patients who show evidence of esophagogastric junction outflow obstruction (EGJOO) as demonstrated by elevated integrated relaxation pressure (IRP) and preserved peristalsis. Our aim is to classify EGJOO patients based on response to amyl nitrite (AN) during high-resolution manometry.

METHODS

Patients were considered to have true EGJOO if elevated IRP during supine swallow persisted in the upright position and was associated with high intrabolus pressure. The EGJ response to AN was compared between patients with achalasia type 2 (A2) and normal esophageal motility. Based on the relaxation gain (deglutitive IRP-AN IRP) value that best discriminated these two groups (10 mm Hg), patients with true EGJOO were categorized as being in either the AN-responsive (AN-R) or AN-unresponsive (AN-U) subgroups.

KEY RESULTS

In the group of 49 patients with true EGJOO, the AN response classified 27 patients (IRP = 25 ± 10 mm Hg) with AN-R and 22 patients (IRP = 20 ± 5 mm Hg) with AN-U (P = 0.2). In AN-R, AN produced a relaxation gain and rebound after-contraction response at the EGJ comparable to A2 patients. AN-U patients had an elevated IRP after AN and a relaxation gain similar to normal esophageal motility patients. AN-U patients were obese and had higher prevalence of sleep apnea (P < 0.05).

CONCLUSIONS

Among patients with true EGJOO, only half have pharmacologic evidence of impaired LES relaxation. Pharmacologic interrogation of the EGJ is thus necessary to identify the subgroup of EGJOO patients who could be expected to benefit from LES ablative therapies.

Achalasia diagnosed despite normal integrated relaxation pressure responds favorably to therapy

BACKGROUND

Achalasia diagnosis requires elevated integrated relaxation pressure (IRP; manometric marker of lower esophageal sphincter [LES] relaxation). Yet, some patients exhibit clinical features of achalasia despite normal IRP and have LES dysfunction demonstrable by other means. We hypothesized these patients to exhibit equivalent therapeutic response compared to standard achalasia patients.

METHODS

Symptomatic achalasia-like cases, despite normal IRP, displayed evidence of impaired LES relaxation using rapid drink challenge (RDC), solid swallows during high-resolution manometry, and/or barium esophagogram; were treated with achalasia therapies and compared to standard achalasia patients with raised IRP. Outcomes included equivalence for short- and long-term symptom response and stasis on barium esophagogram.

KEY RESULTS

Twenty-nine normal IRP achalasia cases (14 males, median age 50 year, median Eckardt 6, barium stasis 12 ± 7 cm) and 29 consecutive standard achalasia controls underwent therapy. Among cases, LES dysfunction was most often identified by RDC and/or barium esophagogram. Short-term symptomatic success was equivalent in cases vs controls (90% vs 93%; 95% CI for difference: -19% to 13%). Median short-term (1 vs 1; 95% CI for difference: 0-1) and long-term Eckardt scores (2 vs 1; 95% CI for difference: 0-2) were similar in cases and controls, respectively. Adequate clearance was observed in 67% of cases vs 81% of controls on post-therapy esophagogram.

CONCLUSIONS AND INFERENCES

We described a subset of achalasia patients with normal IRP, but impaired LES relaxation identifiable only on additional provocative tests. These patients benefited from treatment, suggesting that such tests should be performed to increase the number of clinically relevant diagnoses.

Rapid drinking challenge during high-resolution manometry is complementary to timed barium esophagogram for diagnosis and follow-up of achalasia

BACKGROUND

Esophageal stasis is a hallmark of achalasia. Timed barium esophagogram (TBE) is used to measure stasis but exposes patients to ionizing radiation. It is suggested that esophageal stasis can be objectified on high-resolution manometry (HRM) as well using a rapid drinking challenge test (RDC). We aimed to assess esophageal stasis in achalasia by a RDC during HRM and compare this to TBE.

METHODS

Thirty healthy subjects (15 male, age 40 [IQR 34-49]) and 90 achalasia patients (53 male, age 47 [36-59], 30 untreated/30 treated symptomatic/30 treated asymptomatic) were prospectively included to undergo HRM with RDC and TBE. RDC was performed by drinking 200 mL of water. Response to RDC was measured by basal and relaxation pressure in the esophagogastric junction (EGJ) and esophageal pressurization during the last 5 seconds.

KEY RESULTS

EGJ basal and relaxation pressure during RDC were higher in achalasia compared to healthy subjects (overall P < .01). Esophageal body pressurization was significantly higher in untreated (43 [33-35 mm Hg]) and symptomatic treated patients (25 [16-32] mm Hg) compared to healthy subjects (6 [3-7] mm Hg) and asymptomatic treated patients (11 [8-15] mm Hg, overall P < .01). A strong correlation was observed between esophageal pressurization during RDC and barium column height at 5 minutes on TBE (r = .75, P < .01), comparable to the standard predictor of esophageal stasis, IRP (r = .66, P < .01).

CONCLUSIONS & INFERENCES

The RDC can reliably predict esophageal stasis in achalasia and adequately measure treatment response to a degree comparable to TBE. We propose to add this simple test to each HRM study in achalasia patients.

Chicago Classification normative metrics in a healthy Indian cohort for a 16-channel water-perfused high-resolution esophageal manometry system

BACKGROUND

High-resolution esophageal manometry (HREM) interpretation by the Chicago Classification (CC) derives its normal values from western volunteers using solid-state catheters. There is no normative data for the 16-channel water-perfused HREM system commonly used in India.

AIMS

To determine normal values for a 16-channel water-perfused HREM catheter in supine posture using healthy volunteers and substitute these normal values (if different from CC values) in the CC v3.0 algorithm.

METHODS

After ethics approval and informed consent, 53 volunteers (31 men) with no gastrointestinal (GI) symptoms or medications affecting GI motility underwent HREM by standard protocol. Age, gender, body mass index (BMI), and manometry parameters analyzed using Trace 1.3.3 software were collected. The median, range, and 5, 10, 75, and 95 percentiles (where applicable) were obtained for all HREM metrics. Normal value percentiles were defined as 95th (integrated relaxation pressure [IRP]), 10th-100th (distal contractile integral [DCI]), and minimum (distal latency [DL]).

RESULTS

The mean age was 30 years and the BMI was 24.2 kg m^-2 . Compared to CC, our normal metrics were lower for IRP (13 mm Hg) and DCI (350-4500 mm Hg s cm). DCI >4500 and <70 (<5th percentile) were defined as hypercontractile and failed contraction, respectively. Abnormal DL (<4.5 s) and peristaltic break size (>5 cm) were similar to CC metrics. Applying these metrics, CC diagnoses changed in 15% (8/53) with downgrading of ineffective motility to fragmented peristalsis or normal, due to lower DCI cutoff used.

CONCLUSIONS

This is the first report of normative data for the 16-channel water-perfused system in supine posture. It revealed lower IRP and DCI, necessitating modification of CC cutoffs for this system.

NORMATIVE VALUES FOR A NEW WATER-PERFUSED HIGH RESOLUTION MANOMETRY SYSTEM

BACKGROUND

Esophageal manometry is the most reliable method to evaluate esophageal motility. High resolution manometry (HRM) provides topographic contour colored plots (Clouse Plots) with simultaneous analysis from the pharynx to the stomach. Both solid state and water-perfused systems are available.

OBJECTIVE

This study aims to determinate the normative data for a new water-perfused HRM.

METHODS

HRM was made in 32 healthy volunteers after 8 hours fasting. HRM system used consisted of a 24-channel water-perfused catheter (Multiplex, Alacer Biomedica, São Paulo, Brazil). The reusable catheter is made of polyvinyl chloride (PVC) with 4.7 mm of diameter. Side holes connected to pressure transducers are spaced 2 cm for the analysis from the pharynx to the lower esophageal sphincter (LES). Holes are spaced 5 mm and 120° in a spiral disposition in the LES area. The sensors encompass 34 cm in total. Upper esophageal sphincter (UES) parameters studied were basal and relaxation pressures. Esophageal body parameters were distal contractile integral (DCI), distal latency (DL) and break. LES parameters studied were basal pressure, integrated residual pressure (IRP), total and abdominal length. Variables are expressed as mean ± standard deviation, median (interquartile range) and percentiles 5-95th.

RESULTS

All volunteers (17 males, aged 22-62 years) completed the study and tolerated the HRM procedure well. Percentiles 5-95th range were calculated: Upper Esophageal Sphincter (UES) basal pressure 16.7-184.37 (mmHg), DL: 6.2-9.1 (s), DCI: 82.72-3836.61 (mmHg.s.cm), break: <7.19 (cm), LES basal pressure: 4.89-37.16 (mmHg), IRP: 0.55-15.45 (mmHg).

CONCLUSION

The performance and normative values obtained for this low-cost water-perfused HRM seems to be adequate for clinical use.

The Esophageal Manometry with Gas-perfused Catheters

Background

The well-established methods for esophageal manometry have some disadvantages: the-water-perfused catheters needs calibration by gravity and measuring in supine position, and the solid-state catheters are very expensive. Manometry using gas-perfused catheters is a suitable alternative. There have been only a few publications about this.

Objectives and methods

The results for esophageal manometry in 1700 patients were retrospectively analyzed based on the clinical reports and the manometry data. The gas-perfusion manometry was critically assessed.

Results

The mean age was 54 years. The indications for esophageal manometry were GER symptoms in 58.5% (pathological DeMeester score in 41.8%), dysphagia in 12.4%, and already known achalasia in 8.9%. Motility disorders could be found in 40% of the patients with GER symptoms (51% of the patients with pathological DeMeester score), and in 88% of achalasia patients. The resting LES pressure was 8.9±5.94 mmHg with GER symptoms, 16.4±12.79 mmHg without GER symptoms, and 26.8±14.03 mmHg with achalasia. The relaxation LES pressure was 20.0±10.93 mmHg in achalasia patients, and 8.3±5.77 mmHg in the others.The gas-perfusion manometry was well tolerated by all patients without any serious complications.

Discussion

Manometry using gas-perfused catheters is an easy to handle and inexpensive method to investigate the esophageal motility. The suitability of gas perfusion with helium for esophageal manometry depends on physical and technical requirements, such as a constant gas flow, a dead space in the transducer, and the catheter being as small as possible. In consideration of this, the detection of the pressure changing in swallowing acts is excellent. The measured LES pressures are generally lower than with other methods like with water-perfused or solid-state catheters, possibly because of the higher compliance in a gas-filled surrounding. The normal values in gas-perfusion manometry are comparable but not identical with the values of other manometric methods.

Normative values and factors affecting water-perfused esophageal high-resolution impedance manometry for a Chinese population

BACKGROUND

Combined esophageal high-resolution impedance manometry (HRIM) measures multiple pressures and bolus transit simultaneously, facilitating detailed assessment of esophageal motility. Currently, normative values for water-perfused HRIM systems for Chinese populations are lacking.

METHODS

Healthy volunteers were enrolled for comprehensive anthropometric measures, blood biochemistry tests, and an HRIM study using 22 water-perfused pressure sensors and 12 impedance channels. Ten 5-mL liquid swallows of saline at 30-second intervals were conducted. The following parameters were calculated: distal contractile integral (DCI), distal latency (DL), lower esophageal sphincter (LES) basal pressure, 4-second integrated relaxation pressure (IRP-4s), and complete bolus transit percentage. Normal values were established based on the 5th and 95th percentiles.

KEY RESULTS

All 66 participants (34 male, 32 female, aged 21-64 years) completed the study and tolerated the HRIM procedure well. The upper normal limit (95th percentile) of IRP-4 second was 20 mmHg. The 5th-95th percentile range for DCI, DL, and complete bolus transit was 99-2186 mmHg●s●cm, 6.2-11.3 second, and 50%-100%, respectively. Age was negatively correlated with DL. Females had significantly higher upper limits for IRP-4s and median DCI than males. Multivariate analyses confirmed that IRP-4s was higher in females, and that higher body mass index and waist circumference were associated with reduced DL and better bolus transit, respectively.

CONCLUSIONS AND INFERENCES

We established normative values for the water-perfused HRIM system for a Chinese population. Gender and anthropometric factors may affect various major HRIM parameters and should be taken into account when interpreting HRIM results in clinical practice.

Impaired motility in Barrett's esophagus: A study using high-resolution manometry with physiologic challenge

BACKGROUND

Esophageal dysmotility may predispose to Barrett's esophagus (BE). We hypothesized that high-resolution manometry (HRM) performed with additional physiologic challenge would better delineate dysmotility in BE.

METHODS

Included patients had typical reflux symptoms and underwent endoscopy, HRM with single water swallows and adjunctive testing with solids and rapid drink challenge (RDC) before ambulatory pH-impedance monitoring. BE and endoscopy-negative reflux disease (ENRD) subjects were compared against functional heartburn patient-controls (FHC). Primary outcome was incidence of HRM contractile abnormalities with standard and adjunctive swallows. Secondary outcomes included clearance measures and symptom association on pH-impedance.

KEY RESULTS

Seventy-eight patients (BE 25, ENRD 27, FHC 26) were included. Water swallow contractility was reduced in both BE (median DCI 87 mm Hg/cm/s) and ENRD (442 mm Hg/cm/s) compared to FHC (602 mm Hg/cm/s; P < .001 and .04, respectively). With the challenge of solid swallows and RDC, these parameters improved in ENRD (solids = 1732 mm Hg/cm/s), becoming similar to FHC (1242 mm Hg/cm/s; P = .93), whereas abnormalities persisted in BE (818 mm Hg/cm/s; P < .01 c.f. FHC). In BE and ENRD, reflux events (67 vs 57 events/24 hour) and symptom frequency were similar; yet symptom correlation was significantly better in ENRD compared to BE, which was comparable to FHC (symptom index 30% vs 4% vs 0%, respectively). Furthermore, bolus clearance and exposure times were more pronounced in BE (P < .01).

CONCLUSIONS & INFERENCES

Reduced contractile effectiveness persisted in BE with the more representative esophageal challenge of swallowing solids and free drinking; while in ENRD and FHC peristalsis usually improved, demonstrating peristaltic reserve. Furthermore, symptom association and refluxate clearance were reduced in BE. These factors may underlie BE pathogenesis.

Variation in esophageal physiology testing in clinical practice: Results from an international survey

BACKGROUND

Advances in clinical measurement of esophageal motility and function have improved the assessment of swallowing disorders and reflux symptoms. Variation in data acquisition, analysis, and reporting exists and impacts on diagnosis and management.

AIMS AND METHODS

This study examined variation in esophageal manometry methodology between institutions to establish the status in current practice. A structured survey was distributed through international NGM societies using an Internet-based platform. Questions explored infrastructure, technology, analysis, and reporting.

KEY RESULTS

Responses were received from 91 centers from 29 countries. Eighteen (20%) centers used "conventional" manometry, 75 (82%) high-resolution manometry, and 53 (58%) HR impedance manometry. All centers documented motility for single water swallows. The Chicago Classification was applied by 65 (71.4%) centers. In contrast, analysis of EGJ morphology varied widely. Adjunctive testing was often applied: multiple rapid swallows (77%), rapid drink challenge (77%), single solid swallows (63%), and a standard test meal (18%). Of 86 (94.5%) units that offered pH impedance (pH-Z) studies, approximately half (53.5%) performed tests on acid-suppressant medication in patients with a high pretest probability (eg, erosive esophagitis). Most (75.6%) centers manually reviewed every reflux event. Others examined pH-Z data only prior to symptoms. To assess symptom association with reflux events, 73.6% centers analyzed each symptom separately, whereas 29.7% centers pooled symptoms.

CONCLUSIONS AND INFERENCES

There is marked variation in the data acquisition, analysis, and reporting of esophageal manometry studies. Further efforts to improve quality and uniformity in testing and reporting are required. This survey provides information upon which best-practice guidelines can be developed.

Normal Values of High-Resolution Manometry in Supine and Upright Positions in a Thai Population

BACKGROUND

Although cut-off values used in high-resolution manometry (HRM) to diagnose esophageal motility disorders are based on representative samples of the US population and assume a supine position, differences in population and body positioning can reportedly affect results.

AIMS

To establish normal HRM values for Thai people in both supine and upright positions.

METHODS

Forty-one healthy subjects were recruited, each of whom underwent solid-state HRM with ten 5-mL swallows of water in both the supine and upright positions. Measuring parameters according to the Chicago classification criteria (CC v3.0) were included, for which the mean, median and 5th and 95th percentiles (PCTLs) were calculated.

RESULTS

The results corresponded with the CC v3.0 criteria, except for the mean, and 5th PCTL of the distal contractile integral (DCI), which were lower for this population. In the upright position, the mean and median values for DCI, intrabolus pressure and integrated relaxation pressure were significantly decreased, whereas the length of the transitional zone was significantly increased. The limitations of this study include: (1) the relatively low number of participants, (2) the limited recruitment of participants only at Ramathibodi Hospital and (3) the limited recruitment of only young and middle-aged participants.

CONCLUSIONS

We established normal values for the HRM parameters in a representative sample of the Thai population. Our supine results still prove that the use of the CC v3.0 is preferable. HRM testing in patients measured in the upright position should be analyzed based on the normative values obtained from upright swallow studies.

Decision Graph Embedding for High-Resolution Manometry Diagnosis

High-resolution manometry is an imaging modality which enables the categorization of esophageal motility disorders. Spatio-temporal pressure data along the esophagus is acquired using a tubular device and multiple test swallows are performed by the patient. Current approaches visualize these swallows as individual instances, despite the fact that aggregated metrics are relevant in the diagnostic process. Based on the current Chicago Classification, which serves as the gold standard in this area, we introduce a visualization supporting an efficient and correct diagnosis. To reach this goal, we propose a novel decision graph representing the Chicago Classification with workflow optimization in mind. Based on this graph, we are further able to prioritize the different metrics used during diagnosis and can exploit this prioritization in the actual data visualization. Thus, different disorders and their related parameters are directly represented and intuitively influence the appearance of our visualization. Within this paper, we introduce our novel visualization, justify the design decisions, and provide the results of a user study we performed with medical students as well as a domain expert. On top of the presented visualization, we further discuss how to derive a visual signature for individual patients that allows us for the first time to perform an intuitive comparison between subjects, in the form of small multiples.

Classification of esophageal motor findings in gastro-esophageal reflux disease: Conclusions from an international consensus group

BACKGROUND

High-resolution manometry (HRM) has resulted in new revelations regarding the pathophysiology of gastro-esophageal reflux disease (GERD). The impact of new HRM motor paradigms on reflux burden needs further definition, leading to a modern approach to motor testing in GERD.

METHODS

Focused literature searches were conducted, evaluating pathophysiology of GERD with emphasis on HRM. The results were discussed with an international group of experts to develop a consensus on the role of HRM in GERD. A proposed classification system for esophageal motor abnormalities associated with GERD was generated.

KEY RESULTS

Physiologic gastro-esophageal reflux is inherent in all humans, resulting from transient lower esophageal sphincter (LES) relaxations that allow venting of gastric air in the form of a belch. In pathological gastro-esophageal reflux, transient LES relaxations are accompanied by reflux of gastric contents. Structural disruption of the esophagogastric junction (EGJ) barrier, and incomplete clearance of the refluxate can contribute to abnormally high esophageal reflux burden that defines GERD. Esophageal HRM localizes the LES for pH and pH-impedance probe placement, and assesses esophageal body peristaltic performance prior to invasive antireflux therapies and antireflux surgery. Furthermore, HRM can assess EGJ and esophageal body mechanisms contributing to reflux, and exclude conditions that mimic GERD.

CONCLUSIONS & INFERENCES

Structural and motor EGJ and esophageal processes contribute to the pathophysiology of GERD. A classification scheme is proposed incorporating EGJ and esophageal motor findings, and contraction reserve on provocative tests during HRM.

High-resolution anorectal manometry: A comparison of solid-state and water-perfused catheters

BACKGROUND

Anorectal manometry is the most commonly performed investigation for assessment of anorectal dysfunction. Findings from previous studies comparing water-perfused (WP) and solid-state (SS) techniques in the anorectum are conflicting. We compared anal sphincter pressure at rest and during dynamic maneuvers (squeezing and coughing) in healthy volunteers using SS and WP high-resolution anorectal manometry (HR-ARM) employing equivalent catheter configurations, a standardized protocol, and identical data acquisition and analysis software.

METHODS

Sixty healthy volunteers (40F; median age: 40; range: 18-74) underwent WP and SS HR-ARM in randomized order. Anal resting pressure, and squeeze and cough increments were measured. Median pressure and 5th and 95th percentiles were calculated for each maneuver and compared using Wilcoxon signed-rank test. Bland and Altman plots were used to assess agreement between the systems. The impact of gender and parity was also explored.

KEY RESULTS

Anal sphincter pressure measurements during squeeze (P<.001) and cough (P<.001) were significantly higher using SS HR-ARM than WP HR-ARM. No differences were seen at rest between the two types of catheter (nulliparous: P=.304; parous: P=.390; males: P=.167). Normal ranges for SS and WP manometry from this small group of healthy volunteers are presented.

CONCLUSIONS & INFERENCES

Greater sensitivity to rapid pressure change is one of the advantages associated with SS HR-ARM. This is reflected in the differences observed during dynamic maneuvers performed during this study. Catheter type should be taken into consideration when selecting normal ranges for comparison to disease states.

A Procedure for the Automatic Analysis of High-Resolution Manometry Data to Support the Clinical Diagnosis of Esophageal Motility Disorders

OBJECTIVE

Degenerative phenomena may affect esophageal motility as a relevant social-health problem. The diagnosis of such disorders is usually performed by the analysis of data from high-resolution manometry (HRM). Inter- and intraobserver variability frequently affects the diagnosis, with potential interpretative and thus therapeutic errors, with unnecessary or worse treatments. This may be avoided with automatic procedures that minimize human intervention in data processing.

METHODS

In order to support the traditional diagnostic process, an automatic procedure was defined considering a specific physiomechanical model that is able to objectively interpret data from HRM. A training set (N = 226) of healthy volunteers and pathological subjects was collected in order to define the model parameters distributions of the different groups of subjects, providing a preliminary database. A statistical algorithm was defined for an objective identification of the patient's healthy or pathological condition by comparing patient parameters with the database.

RESULTS

A collection of HRMs including subjects of the training set has been built. Statistical relationships between parameters and pathologies have been established leading to a preliminary database. An automatic diagnosis procedure has been developed to compare model parameters of a specific patient with the database. The procedure was able to match the correct diagnosis up to 86% of the analyzed subjects.

CONCLUSION

The success rate of the automatic procedure addresses the suitability of the developed algorithms to provide a valid support to the clinicians for the diagnostic activity.

SIGNIFICANCE

The objectivity of developed tools increases the reliability of data interpretation and, consequently, patient acceptance.

Upper esophageal sphincter motility in gastroesophageal reflux disease in the light of the high-resolution manometry

This study aims to evaluate the upper esophageal sphincter (UES) motility in patients with gastroesophageal reflux disease (GERD) as compared to healthy volunteers. We retrospectively studied the HRM tests of 44 patients (median age: 61 years, 54% females) under evaluation for GERD. The manometric UES parameters of these patients were compared to 40 healthy volunteers (median age: 27 years, 50% females). Almost half of the patients had a short and hypotonic UES. Patients with extraesophageal symptoms had a higher proportion of hypotonic UES as compared to patients with esophageal symptoms. Reflux pattern did not influence manometric parameters. Proximal reflux (any number of episodes) was present in 37(84%) patients (median number of proximal episodes = 6). Manometric parameters are similar in the presence or absence of proximal reflux. There is not a correlation between the UES length and UES basal pressure. In conclusion, our results show that: (1) the manometric profile of the UES in patients with GERD is characterized by a short and hypotonic UES in half of the patients; (2) this profile is more pronounced in patients with extraesophageal symptoms; and (3) neither the presence of proximal reflux nor reflux pattern bring a different manometric profile.

Comparison of two high-resolution manometry software systems in evaluating esophageal motor function

BACKGROUND

High-resolution manometry (HRM) utilizes software tools to diagnose esophageal motor disorders. Performance of these software metrics could be affected by averaging and by software characteristics of different manufacturers.

METHODS

High-resolution manometry studies on 86 patients referred for antireflux surgery (61.6 ± 1.4 year, 70% F) and 20 healthy controls (27.9 ± 0.7 year, 45% F) were first subject to standard analysis (Medtronic, Duluth, GA, USA). Coordinates for each of 10 test swallows were exported and averaged to generate a composite swallow. The swallows and averaged composites were imported as ASCII file format into Manoview (Medtronic) and Medical Measurement Systems database reporter (MMS, Dover, NH, USA), and analyses repeated. Comparisons were made between standard and composite swallow interpretations.

KEY RESULTS

Correlation between the two systems was high for mean distal contractile integral (DCI, r² ≥ 0.9) but lower for integrated relaxation pressure (IRP, r² = 0.7). Excluding achalasia, six patients with outflow obstruction (mean IRP 23.2 ± 2.1 with 10-swallow average) were identified by both systems. An additional nine patients (10.5%) were identified as outflow obstruction (15 mmHg threshold) with MMS 10-swallow and four with MMS composite swallow evaluation; only one was confirmed. Ineffective esophageal motility was diagnosed by 10-swallow evaluation in 19 (22.1%) with Manoview, and 20 (23.3%) with MMS. On Manoview composite, 17 had DCI <450 mmHg/cm/s, and on MMS composite, 21, (p ≥ 0.85 for each comparison) but these did not impact diagnostic conclusions.

CONCLUSIONS & INFERENCES

Comparison of 10 swallow and composite swallows demonstrate variability in software metrics between manometry systems. Our data support use of manufacturer specific software metrics on 10-swallow sequences.

Oesophageal Manometry in Experimental Pigs: Methods and Initial Experience

The aim of this study project was to prepare our own method of porcine oesophageal manometry. Ten mature experimental pigs entered the study. Conventional water-perfused system was decided for manometry. Porcine resting and relaxed pressures of the lower oesophageal sphincter are fully comparable with healthy human subjects. Evocable swallowing is doable and oesophageal peristalsis is quantifiable. Basic manometric parameters were different in male and female animals. Oesophageal manometry in experimental pigs is feasible. Porcine oesophageal manometry will be usable for preclinical studies in future.

Characterization and follow-up of esophagogastric junction outflow obstruction detected by high resolution manometry

BACKGROUND

Esophagogastric junction outflow obstruction (EGJOO) is a newly described diagnostic entity growing in importance due to the use of high resolution manometry (HRM). There is little knowledge regarding its incidence, etiopathogeny, long-term evolution, and most suitable treatment. Our objective was to increase the awareness of EGJOO to optimize the management of these patients.

METHODS

We conducted a historical (retrospective and prospective) study of patients diagnosed with EGJOO using HRM combined with multichannel intraluminal impedance, comparing their manometric and impedance characteristics with those of a control group. Symptoms, etiology of obstruction, acid exposure, clinical course (and its associated factors), and response to treatment were also evaluated in the EGJOO group.

KEY RESULTS

Forty-four subjects were included (28 patients and 16 controls). Esophagogastric junction outflow obstruction patients presented incomplete esophageal transit more frequently than controls. Patients with structural obstruction had dysphagia more frequently than patients with functional obstruction, and different manometric, impedance, and pH-metric patterns. Over one-third of the EGJOO patients presented a spontaneous resolution of symptoms without EGJOO treatment. In the multivariate analysis, the variables associated with this spontaneous symptomatic resolution included typical symptoms of gastro-esophageal reflux disease or epigastralgia as the main symptom and resting or basal pressure of the upper esophageal sphincter <50 mmHg.

CONCLUSIONS & INFERENCES

The majority of EGJOO patients presented intact peristalsis which may compensate for the lack of EGJ relaxation. In the EGJOO patients presenting favorable factors associated with a spontaneous resolution of symptoms, invasive treatments should be considered with special caution. Structural etiologies are more amenable to management, while the remainder may improve without intervention.

Characterization of idiopathic esophagogastric junction outflow obstruction

BACKGROUND

Esophagogastric junction (EGJ) outflow obstruction is a manometric diagnosis, characterized by an elevated relaxation pressure (IRP4) of the lower esophageal sphincter (LES) and intact or weak peristalsis. The etiology and preferred treatment remain unknown. We describe a large patient cohort in detail, for a better understanding of this rare disorder.

METHODS

We included 47 patients, diagnosed with EGJ outflow obstruction on high-resolution manometry (HRM) between 2012 and December 2014.

KEY RESULTS

Idiopathic EGJ outflow obstruction was diagnosed in 34 patients. The majority (91%) of patients presented with retrosternal pain or dysphagia. The median (IQR) for various HRM parameters was IRP4, 18.9 mmHg (18-23); intrabolus pressure (IBP), 8.3 mmHg (5-12) and basal LES pressure, 27.5 mmHg (22-33). Peristaltic breaks were seen in 88% and elevated IBPmax in 74% of patients. No patients had stasis, difficult LES passage or esophageal dilation on endoscopy. Only 7/25 patients (28%) had stasis on barium esophagography. In 26 patients (82%), no treatment was required: 18 had symptoms judged unrelated to outflow obstruction, 5 had spontaneous symptom relief, and 3 declined therapy. Eight patients were treated: five received botox injections with a good but short-lived effect, three received pneumatic dilatation, of which one was successful. Three patients were diagnosed with achalasia on a subsequent manometry.

CONCLUSIONS & INFERENCES

Primary EGJ outflow obstruction has an unclear clinical significance. A substantial part of patients has unrelated symptoms, spontaneous symptom relief, or no stasis. Treated patients showed a beneficial response to botox injections. A small proportion develops achalasia at follow-up.

Predictive value of routine esophageal high-resolution manometry for gastro-esophageal reflux disease

BACKGROUND

Using conventional manometry, gastro-esophageal reflux disease (GERD) was associated with a reduced lower esophageal sphincter (LES) pressure and impaired peristalsis. However, with a large overlap between GERD patients and controls, these findings are of limited clinical relevance. It is uncertain whether the more detailed information of high-resolution manometry (HRM) can discriminate GERD patients. Therefore, we aimed to determine to which extent HRM findings can predict GERD.

METHODS

HRM measurements in 69 patients with GERD and 40 healthy subjects were compared and the predictive value of HRM for the diagnosis of GERD was explored.

KEY RESULTS

GERD patients had a significantly lower contraction amplitude (55 vs 64 mmHg; p = 0.045) and basal LES pressure (10 vs 13.2 mmHg; p = 0.034) than healthy controls. GERD patients more often had a hiatal hernia than healthy subjects (30% vs 7%; p = 0.005). Patients with reflux esophagitis had a lower DCI than patients without reflux esophagitis (558 vs 782 mmHg cm s; p = 0.045). No significant difference was seen in contractile front velocity, distal latency, number of peristaltic breaks, residual LES pressure and LES length. On multivariate logistic regression analysis, both esophagogastric junction type I (OR 4.971; 95% CI 1.33-18.59; p = 0.017) and mean wave amplitude (OR 0.95; 95% CI 0.90-0.98; p = 0.013) were found to be independent predictors of GERD. However, the sensitivity and specificity of these findings were low.

CONCLUSIONS & INFERENCES

Hiatal hernia, low contraction amplitude and LES pressure are associated with GERD, but do not predict the disease with sufficient accuracy. Routine esophageal HRM can therefore not be used to distinguish GERD patients from healthy subjects.

Determinants of pressure drift in Manoscan(™) esophageal high-resolution manometry system

BACKGROUND

Manoscan(™) is one of the commonly used high-resolution manometry (HRM) systems with declared measurement accuracy of 1-2 mmHg. However, the accuracy of pressure measurements is limited by development of pressure drift (PD) throughout recording. To date, there has been no systematic investigation to identify the factors contributing to PD. The aim of the present study was to characterize the frequency and magnitude of PD in Manoscan(™) system and identify the factors contributing to PD.

METHODS

Records of 560 consecutive clinical esophageal HRM studies recorded by six distinct HRM catheters were retrospectively reviewed. PD was defined as the residual pressure measurement by each sensor immediately after removal of the catheter. Non-parametric locally weighted regression analysis was performed to assess the effect of duration of study, number of prior uses of a catheter, peak and average pressure exposure during a study on the PD.

KEY RESULTS

The majority (95%) of clinical manometry studies showed a non-negligible PD of more than 5 mmHg. The overall PD was 13 ± 5 mmHg and the sensor with greatest amount of PD showed 23 ± 12 mmHg of drift. The upper esophageal sphincter showed the highest PD. Average pressure exposure of a sensor throughout the recording was the most important predictor of PD. PD inversely correlated with number of prior uses of a catheter.

CONCLUSIONS & INFERENCES

The PD preferentially affects esophageal high-pressure zones, and strongly correlates with 'average pressure exposure' of a sensor during manometry. Available algorithms of the analysis software do not adequately correct the PD.

Normative values in esophageal high-resolution manometry

BACKGROUND

Esophageal high-resolution manometry (HRM) has rapidly gained much popularity worldwide. The Chicago Classification for esophageal motility disorders is based on a set of normative values for key metrics that was obtained using one of the commercially available HRM systems. Thus, it is of great importance to evaluate whether these normative values can be used for other HRM systems as well.

PURPOSE

In this review, we describe the presently available HRM systems, the currently known normative thresholds and the factors that influence them, and assess the use of these thresholds. Numerous factors including the type of HRM system, demographic factors, catheter diameter, body position during testing, consistency of bolus swallows, and esophageal length have an influence on the normative data. It would thus be ideal to have different sets of normal values for each of these factors, yet at the moment the amount of normative data is limited. We suggest broadening the normal range for parameters, as this would allow abnormal values to be of more significance. In addition, we suggest conducting studies to assess the physiological relevance of abnormal values and stress that for each system different normative thresholds may apply.

Evaluation of esophagogastric junction relaxation by 4-second Integrated Relaxation Pressure in achalasia using High Resolution Manometry with water-perfused catheters

BACKGROUND

Relaxation of the esophagogastric junction (EGJ) is now evaluated calculating 4-second integrated relaxation pressure (4-s IRP) by high resolution manometry (HREPT). Solid-state catheters have been used to define abnormal values. Our aim was to evaluate 4-s IRP in esophageal achalasia using HREPT with perfused catheters.

METHODS

From June 2009 to June 2013, 936 HREPT studies have been performed in our unit. Of these, 194 patients having treated achalasia were excluded. Control group was constituted by 695 patients without achalasia, and 47 patients with untreated achalasia constituted the study group. HREPT was performed with water-perfused catheters. To establish the cut-off value for 4-s IRP that better discriminate patients with achalasia from all other patients, a receiver operating characteristic (ROC) analysis was performed.

KEY RESULTS

Twenty three of 47 achalasia patients (49%) showed a 4-s IRP under 15 mmHg; and seven (15%) had a value under modified Chicago criteria. A cut-off value for 4-s IRP of 6.5 mmHg, calculated by ROC analysis, highly discriminates achalasia from the rest of the patients and especially from scleroderma patients (area under the curve: 0.997, 95% CI: 0.995-1.000; p < 0.001).

CONCLUSIONS & INFERENCES

Cut-off values for 4-s IRP defined using HREPT with solid-state catheters are not adequate for diagnosing esophageal achalasia with water-perfused systems. A lower value, i.e., 6.5 mmHg, is suggested for this equipment. The diagnostic criteria of esophageal achalasia should be modified for HREPT performed with water-perfused systems.

The Chicago classification of motility disorders: an update

The Chicago Classification defines esophageal motility disorders in high resolution manometry. This is based on individual scoring of 10 swallows performed in supine position. Disorders of esophago-gastric junction (EGJ) outflow obstruction are defined by a median integrated relaxation pressure above the limit of normal and divided into 3 achalasia subtypes and EGJ outflow obstruction. Major motility disorders (aperistalsis, distal esophageal spasm, and hypercontractile esophagus) are patterns not encountered in controls in the context of normal EGJ relaxation. Finally with the latest version of the Chicago Classification, only two minor motor disorders are considered: ineffective esophageal motility and fragmented peristalsis.

Prevalence of esophageal motility abnormalities increases with longer disease duration in adult patients with eosinophilic esophagitis

BACKGROUND

During the natural course of eosinophilic esophagitis (EoE), the risk for esophageal stricture formation increases. It remains unknown whether motility abnormalities in EoE also develop over time. We aimed to determine the relationship between disease duration, clinical characteristics, and manometric pattern of EoE patients.

METHODS

We compared esophageal high-resolution manometry (HRM) measurements of 31 adult EoE patients with HRM data from 31 GERD controls and 31 healthy controls. Subsequently, we assessed differences in disease duration and clinical characteristics between EoE patients with normal and those with abnormal esophageal motility.

KEY RESULTS

In EoE patients, peristaltic integrity was more frequently failed (12 vs 6%) or weak (27 vs 15%; p < 0.001) compared with healthy controls; however, this pattern was also seen in GERD controls (failed 14%, weak 27%). We found no differences regarding symptoms and signs of EoE between EoE patients with normal (42%) and abnormal motility (58%). However, disease duration was longer in EoE patients with abnormal motility than in those with normal motility (13 (6-18) years vs 4 (1-11) years; p < 0.05). In EoE, but not GERD, disease duration was identified as a risk factor for abnormal motility (OR for each year 1.142; 95% CI 1.004-1.299), and with longer disease duration, the prevalence of abnormal motility increased from 36% (duration 0-5 years) to 83% (duration ≥16 years; p < 0.05).

CONCLUSIONS & INFERENCES

Weak and failed peristaltic integrity are more often present in adult EoE patients than in healthy controls. The prevalence of manometric abnormalities in EoE patients increases with longer disease duration.