Mechanisms of repetitive retrograde contractions in response to sustained esophageal distension: a study evaluating patients with postfundoplication dysphagia

Repetitive retrograde contractions (RRCs) in response to sustained esophageal distension are a distinct contractility pattern observed with functional luminal imaging probe (FLIP) panometry that are common in type III (spastic) achalasia. RRCs are hypothesized to be indicative of either impaired inhibitory innervation or esophageal outflow obstruction. We aimed to apply FLIP panometry to patients with postfundoplication dysphagia (a model of esophageal obstruction) to explore mechanisms behind RRCs. Adult patients with dysphagia after Nissen fundoplication ( n = 32) or type III achalasia ( n = 25) were evaluated with high-resolution manometry (HRM) and upper endoscopy with FLIP. HRM studies were assessed for outflow obstruction and spastic features: premature contractility, hypercontractility, and impaired deglutitive inhibition during multiple-rapid swallows. FLIP studies were analyzed to determine the esophagogastric junction (EGJ)-distensibility index and contractility pattern, including RRCs. Barium esophagram was evaluated when available. RRCs were present in 8/32 (25%) fundoplication and 19/25 (76%) achalasia patients ( P < 0.001). EGJ outflow obstruction was detected in 21 (67%) fundoplication patients by HRM, FLIP, or esophagram [6 (29%) had RRCs]. On HRM, none of the fundoplication patients had premature contractility, whereas 3/4 with defective inhibition on multiple-rapid swallows and 2/4 with hypercontractility had RRCs. Regression analysis demonstrated HRM with spastic features, but not esophageal outflow obstruction, as a predictor for RRCs. RRCs in response to sustained esophageal distension appear to be a manifestation of spastic esophageal motility. Although future study to further clarify the significance of RRCs is needed, RRCs on FLIP panometry should prompt evaluation for a major motor disorder. NEW & NOTEWORTHY Repetitive retrograde contractions (RRCs) are a common response to sustained esophageal distension among spastic achalasia patients when evaluated with the functional luminal imaging probe. We evaluated patients with postfundoplication dysphagia, i.e., patients with suspected mechanical obstruction, and found that RRCs occasionally occurred among postfundoplication patients, but often in association with manometric features of esophageal neuromuscular imbalance. Thus, RRCs appear to be a manifestation of spastic esophageal dysmotility, likely from neural imbalance resulting in excess excitation.

Abnormal esophageal acid exposure on high-dose proton pump inhibitor therapy is common in systemic sclerosis patients

BACKGROUND

Esophageal dysfunction and gastro-esophageal reflux disease (GERD) are common among patients with systemic sclerosis (SSc). Although high-dose proton pump inhibitors (PPIs) typically normalize esophageal acid exposure, the effectiveness of PPI therapy has not been systematically studied in SSc patients. The aim of this study was to characterize reflux in SSc patients on high-dose PPI using esophageal pH-impedance testing.

METHODS

In this case-controlled retrospective analysis, 38 patients fulfilling 2013 American College of Rheumatology SSc criteria who underwent esophageal pH-impedance testing on twice-daily PPI between January 2014 and March 2017 at a tertiary referral center were compared with a control-cohort of 38 non-SSc patients matched for PPI formulation and dose, hiatal hernia size, age, and gender. Patient clinical characteristics, including endoscopy and high-resolution manometry findings, were assessed via chart review.

KEY RESULTS

On pH-impedance, SSc patients had higher acid exposure times (AETs) than controls. Sixty-one percent of the SSc patients and 18% of the control patients had a total AET ≥4.5% (P < .001). Systemic sclerosis patients also had significantly longer AETs, longer median bolus clearance, and lower nocturnal impedance values.

CONCLUSIONS & INFERENCES

Abnormal esophageal acid exposure despite high-dose PPI therapy was common among patients with SSc. The lack of increased reflux episodes in the SSc patients, and longer bolus clearance times and lower nocturnal impedance, supports ineffective clearance as the potential mechanism. Systemic sclerosis patients may require adjunctive therapies to PPIs to control acid reflux.

High-resolution manometry assessment of the lower esophageal sphincter after-contraction: Normative values and clinical correlation

BACKGROUND

The Chicago Classification v3.0 proposed extending the distal contractile integral (DCI) measurement domain to include the lower esophageal sphincter (LES) to enhance the detection of esophageal hypercontractility. However, normative and clinical data for this approach are unreported. We aimed to describe the application of an extended DCI measurement in asymptomatic controls and patients.

METHODS

High-resolution manometry (HRM) of 65 asymptomatic controls and 72 patients with normal motility were evaluated retrospectively. Dysphagia and chest pain symptoms were assessed using the brief esophageal dysphagia questionnaire (BEDQ); ≥10 was considered abnormal. HRM studies of 10 supine swallows were evaluated via the standard DCI and an extended DCI measurement domain (DCI+) to include the lower esophageal sphincter (LES) during and after the peristaltic wave. The DCI-increment was calculated as the DCI+ minus DCI.

KEY RESULTS

Among controls, the median (5-95th percentile) DCI+ was 1915 (1359-6921) mm Hg/cm/s and DCI-increment was 534 (126-1488) mm Hg/cm/s. Two patients (3%) had ≥2 swallows with DCI+ >8000 mm Hg/cm/s and seven (10%) patients had at least one swallow with DCI+ >8000 mm Hg/cm/s, ie, had potential motility reclassification by application of DCI+. Seven of these nine patients (78%) were evaluated for dysphagia or chest pain, but only 3/9 (33%) had an abnormal BEDQ.

CONCLUSIONS AND INFERENCES

Extension of the DCI measurement domain may aid quantifying hypercontractility that involves the LES. However, adjusting management strategies based on reclassification of patients with otherwise normal motility should be cautiously considered.

A System to Assess the Competency for Interpretation of Esophageal Manometry Identifies Variation in Learning Curves

BACKGROUND & AIMS

Quality esophageal high-resolution manometry (HRM) studies require competent interpretation of data. However, there is little understanding of learning curves, training requirements, or measures of competency for HRM. We aimed to develop and use a competency assessment system to examine learning curves for interpretation of HRM data.

METHODS

We conducted a prospective multicenter study of 20 gastroenterology trainees with no experience in HRM, from 8 centers, over an 8-month period (May through December 2015). We designed a web-based HRM training and competency assessment system. After reviewing the training module, participants interpreted 50 HRM studies and received answer keys at the fifth and then at every second interpretation. A cumulative sum procedure produced individual learning curves with preset acceptable failure rates of 10%; we classified competency status as competency not achieved, competency achieved, or competency likely achieved.

RESULTS

Five (25%) participants achieved competence, 4 (20%) likely achieved competence, and 11 (55%) failed to achieve competence. A minimum case volume to achieve competency was not identified. There was no significant agreement between diagnostic accuracy and accuracy for individual HRM skills.

CONCLUSIONS

We developed a competency assessment system for HRM interpretation; using this system, we found significant variation in learning curves for HRM diagnosis and individual skills. Our system effectively distinguished trainee competency levels for HRM interpretation and contrary to current recommendations, found that competency for HRM is not case-volume specific.

Improvement in Esophageal Distensibility in Response to Medical and Diet Therapy in Eosinophilic Esophagitis

Objectives:

We aimed to evaluate the effect of medical and diet therapies on esophageal distensibility assessed using the functional lumen imaging probe (FLIP) and the association of changes in esophageal distensibility with clinical outcomes in eosinophilic esophagitis (EoE).

Methods:

Patients with EoE were evaluated with FLIP during endoscopy at baseline and following therapy without interval dilatation. Evaluation also included a validated patient-reported outcome (PRO; a positive PRO was considered at a 30% score improvement), mucosal biopsies, and scoring of endoscopic features of EoE. FLIP data were analyzed to calculate the distensibility plateau (DP).

Results:

In all, 18 patients (ages 19–54 years; 4 female) treated with topical steroid (8), elimination diet (6), and/or proton-pump inhibitor (4 only treated with proton-pump inhibitor) were included. Follow-up testing occurred at a mean (range) of 14.6 (8–28) weeks. Improvement was observed in DP (13.9 (12.2–19.2) to 16.8 mm (15.8–19.2), P=0.007) and peak eosinophil count (45 (29–65) to 23 per high-power field (h.p.f.) (5–53), P=0.042). Nine patients had a positive symptomatic outcome. Six of 8 (75%) patients with a DP increase ≥2 mm had a positive PRO (P=0.077), while 2 of 7 (29%) patients that achieved an eosinophil count <15/h.p.f. had a positive PRO (P=0.167).

Conclusions:

Improvement in esophageal body distensibility can be achieved with medical and diet therapies without dilation in EoE. Improved DP appeared to be better indicator of symptomatic improvement than eosinophil count, supporting FLIP as a valuable outcome measure in EoE.

Editorial: Widening the Use of the Functional Lumen Imaging Probe to Kids With Eosinophilic Esophagitis: Esophageal Narrowing is not Just an Adult Problem

The functional lumen imaging probe (FLIP) provides objective measurement of esophageal distensibility, thus offering a unique and potentially valuable assessment in eosinophilic esophagitis (EoE). Menard-Katcher and colleagues report the first study evaluating use of FLIP in pediatric patients that demonstrated a reduction in esophageal distensibility in patients with EoE compared to patients without EoE. An increase in esophageal distensibility was observed with age among pediatric patients without EoE, but not among those with EoE. While this study further supports the promise of esophageal distensibility assessment in EoE, future work remains needed to optimize FLIP utilization in both research and clinical settings.

Assessing the pre- and postpeak phases in a swallow using esophageal pressure topography

BACKGROUND

The current paradigm of measuring esophageal contractile vigor assesses the entirety of a pressure wave using a single measurement, the distal contractile integral (DCI). We hypothesize that an assessment identifying separate phases of the contractile pressure wave before and after the pressure peak may help distinguish abnormalities in patients presenting with chest pain and dysphagia. The aim of the present study was to develop a technique to assess the individual phases and report on the values in healthy controls.

METHODS

Seventy-one healthy controls were enrolled. High-resolution manometry studies of five intact liquid swallows in both supine and upright positions were analyzed using a customized MATLAB program to divide swallows into a prepeak phase and postpeak phase, and compute the contractile integral of both phases. The contractile integrals were also controlled by duration over each phase.

KEY RESULTS

The composite DCI measurement in healthy controls appears to be weighted toward slightly higher contractile activity during postpeak phase based on postpeak to prepeak ratios in both the supine and upright position (1.50 and 1.49, respectively). The contribution of postpeak phase on the composite DCI was weakened when controlled by time (0.92 and 0.96 in both supine and upright position, respectively).

CONCLUSIONS AND INFERENCES

We developed a novel measurement focused on separating the prepeak and postpeak components of the peristaltic contractile activity during swallowing. Using this technique, it appears that overall contractile activity is higher during postpeak phase and this is related to the longer time component during this phase.

Application of the Functional Lumen Imaging Probe to Esophageal Disorders

OPINION STATEMENT

The functional luminal imaging probe (FLIP) provides a novel method to evaluate esophageal physiology and function in both health and disease. FLIP enables assessment of a previously underexplored component of esophageal function, distensibility, by utilizing high-resolution impedance planimetry to evaluate the relationship of the esophageal luminal geometry with pressure during controlled volumetric distension. Recent studies have described the potential utility of FLIP to evaluate the severity and effectiveness of therapy for esophageal diseases including achalasia, gastroesophageal reflux disease, and eosinophilic esophagitis. This review summarizes these emerging clinical applications of FLIP in the evaluation and management of esophageal diseases.

High-resolution impedance manometry parameters enhance the esophageal motility evaluation in non-obstructive dysphagia patients without a major Chicago Classification motility disorder

BACKGROUND

High-resolution impedance manometry (HRIM) allows evaluation of esophageal bolus retention, flow, and pressurization. We aimed to perform a collaborative analysis of HRIM metrics to evaluate patients with non-obstructive dysphagia.

METHODS

Fourteen asymptomatic controls (58% female; ages 20-50) and 41 patients (63% female; ages 24-82), 18 evaluated for dysphagia and 23 for reflux (non-dysphagia patients), with esophageal motility diagnoses of normal motility or ineffective esophageal motility, were evaluated with HRIM and a global dysphagia symptom score (Brief Esophageal Dysphagia Questionnaire). HRIM was analyzed to assess Chicago Classification metrics, automated pressure-flow metrics, the esophageal impedance integral (EII) ratio, and the bolus flow time (BFT).

KEY RESULTS

Significant symptom-metric correlations were detected only with basal EGJ pressure, EII ratio, and BFT. The EII ratio, BFT, and impedance ratio differed between controls and dysphagia patients, while the EII ratio in the upright position was the only measure that differentiated dysphagia from non-dysphagia patients.

CONCLUSIONS & INFERENCES

The EII ratio and BFT appear to offer an improved diagnostic evaluation in patients with non-obstructive dysphagia without a major esophageal motility disorder. Bolus retention as measured with the EII ratio appears to carry the strongest association with dysphagia, and thus may aid in the characterization of symptomatic patients with otherwise normal manometry.

Incidence and Prevalence of Achalasia in Central Chicago, 2004-2014, Since the Widespread Use of High-Resolution Manometry

BACKGROUND & AIMS

Reported global incidence and prevalence values for achalasia vary widely, from 0.03 to 1.63 per 100,000 persons per year and from 1.8 to 12.6 per 100,000 persons per year, respectively. This study aimed to reconcile these low values with findings from a major referral center, in central Chicago (which began using high-resolution manometry in 2004 and used it in all clinical studies since 2005), and has determined the incidence and prevalence of achalasia to be much greater.

METHODS

We collected data from the Northwestern Medicine Enterprise Data Warehouse database (tertiary care setting) of adults residing in Chicago with an encounter diagnosis of achalasia from 2004 through 2014. Patient files were reviewed to confirm diagnosis and residential address. US Census Bureau population data were used as the population denominator. We assumed that we encountered every incident case in the city to calculate incidence and prevalence estimates. Data were analyzed for the city at large and for the 13 zip codes surrounding the Northwestern Memorial Hospital (NMH), the NMH neighborhood.

RESULTS

We identified 379 cases (50.9% female) that met the full inclusion criteria; of these, 246 were incident cases. Among these, 132 patients resided in the NMH neighborhood, 89 of which were incident cases. Estimated yearly incidences were stable over the study period, ranging from 0.77 to 1.35 per 100,000 citywide (average, 1.07 per 100,000) and from 1.41 to 4.60 per 100,000 in the NMH neighborhood (average, 2.92 per 100,000). The corresponding prevalence values increased progressively, from 4.68 to 14.42 per 100,000 citywide and from 15.64 to 32.58 per 100,000 in the NMH neighborhood.

CONCLUSIONS

The incidence and prevalence of achalasia in central Chicago diagnosed using state-of-the-art technology and diagnostic criteria are at least 2- to 3-fold greater than previous estimates. Additional studies are needed to determine the generalizability of these data to other regions.

Evaluation of Esophageal Motility Utilizing the Functional Lumen Imaging Probe

OBJECTIVES

Esophagogastric junction (EGJ) distensibility and distension-mediated peristalsis can be assessed with the functional lumen imaging probe (FLIP) during a sedated upper endoscopy. We aimed to describe esophageal motility assessment using FLIP topography in patients presenting with dysphagia.

METHODS

In all, 145 patients (aged 18-85 years, 54% female) with dysphagia that completed upper endoscopy with a 16-cm FLIP assembly and high-resolution manometry (HRM) were included. HRM was analyzed according to the Chicago Classification of esophageal motility disorders; major esophageal motility disorders were considered "abnormal". FLIP studies were analyzed using a customized program to calculate the EGJ-distensibility index (DI) and generate FLIP topography plots to identify esophageal contractility patterns. FLIP topography was considered "abnormal" if EGJ-DI was <2.8 mm²/mm Hg or contractility pattern demonstrated absent contractility or repetitive, retrograde contractions.

RESULTS

HRM was abnormal in 111 (77%) patients: 70 achalasia (19 type I, 39 type II, and 12 type III), 38 EGJ outflow obstruction, and three jackhammer esophagus. FLIP topography was abnormal in 106 (95%) of these patients, including all 70 achalasia patients. HRM was "normal" in 34 (23%) patients: five ineffective esophageal motility and 29 normal motility. In all, 17 (50%) had abnormal FLIP topography including 13 (37%) with abnormal EGJ-DI.

CONCLUSIONS

FLIP topography provides a well-tolerated method for esophageal motility assessment (especially to identify achalasia) at the time of upper endoscopy. FLIP topography findings that are discordant with HRM may indicate otherwise undetected abnormalities of esophageal function, thus FLIP provides an alternative and complementary method to HRM for evaluation of non-obstructive dysphagia.

High-Resolution Impedance Manometry Metrics of the Esophagogastric Junction for the Assessment of Treatment Response in Achalasia

OBJECTIVES

We aimed to evaluate the value of novel high-resolution impedance manometry (HRIM) metrics, bolus flow time (BFT), and esophagogastric junction (EGJ) contractile integral (CI), as well as EGJ pressure (EGJP) and the integrated relaxation pressure (IRP), as indicators of treatment response in achalasia.

METHODS

We prospectively evaluated 75 patients (ages 19-81, 32 female) with achalasia during follow-up after pneumatic dilation or myotomy with Eckardt score (ES), timed-barium esophagram (TBE), and HRIM. Receiver-operating characteristic (ROC) curves for good symptomatic outcome (ES≤3) and good radiographic outcome (TBE column height at 5 min<5 cm) were generated for each potential predictor of treatment response (EGJP, IRP, BFT, and EGJ-CI).

RESULTS

Follow-up occurred at a median (range) 12 (3-291) months following treatment. A total of 49 patients had good symptomatic outcome and 46 had good radiographic outcome. The area-under-the-curves (AUCs) on the ROC curve for symptomatic outcome were 0.55 (EGJP), 0.62 (IRP), 0.77 (BFT) and 0.56 (EGJ-CI). The AUCs for radiographic outcome were 0.64 (EGJP), 0.48 (IRP), 0.73 (BFT), and 0.65 (EGJ-CI). Optimal cut-points were determined as 11 mm Hg (EGJP), 12 mm Hg (IRP), 0 s (BFT), and 30 mm Hg•cm (EGJ-CI) that provided sensitivities/specificities of 57%/46% (EGJP), 65%/58% (IRP), 78%/77% (BFT), and 53%/62% (EGJ-CI) to predict symptomatic outcome and 57%/66% (EGJP), 57%/41% (IRP), 76%/69% (BFT), and 57%/66% (EGJ-CI) to predict radiographic outcome.

CONCLUSIONS

BFT, a novel HRIM metric, provided an improved functional assessment over manometric measures of EGJP, IRP, and EGJ-CI at follow-up after achalasia treatment and may help direct clinical management.

Loss of Peristaltic Reserve, Determined by Multiple Rapid Swallows, Is the Most Frequent Esophageal Motility Abnormality in Patients With Systemic Sclerosis

We assessed peristaltic reserve using multiple rapid swallows (MRS) during esophageal high-resolution manometry (HRM) of 111 patients with systemic sclerosis (89 women; ages, 42-64 y). We performed a retrospective analysis of HRM studies that included MRS in patients with systemic sclerosis, performed at 2 tertiary referral centers, and compared data with those from 18 healthy volunteers (controls). HRM findings were analyzed according to the Chicago Classification to provide an esophageal motility diagnosis. Response to MRS was evaluated for the presence of contraction and for augmentation, defined as the distal contractile integral after MRS greater than the median distal contractile integral of 10 supine swallows. Esophageal motility diagnoses included 41% with absent contractility, 31% with normal motility, 23% with ineffective esophageal motility, and 5% that met the criteria for other esophageal motility disorders. Contraction (37%) and peristaltic augmentation (18%) after MRS were observed less frequently in patients with systemic sclerosis than in controls (83% and 100%, respectively). Impaired peristaltic reserve, as assessed with MRS during HRM, is therefore the most common esophageal motility finding among patients with systemic sclerosis.

The association between systemic sclerosis disease manifestations and esophageal high-resolution manometry parameters

BACKGROUND

We aimed to evaluate the associations between systemic sclerosis (SSc)-related systemic manifestations and esophageal function using high-resolution manometry (HRM).

METHODS

Patients with SSc that had undergone HRM between 1/2004 and 9/2014 were identified and HRMs were analyzed according to the Chicago Classification. Clinical characteristics were identified via retrospective chart review and compared among motility diagnoses while adjusting for age, gender, race, and SSc-disease duration.

KEY RESULTS

Seventy-nine patients (85% female, ages 25-77) were included. Clinical characteristics were compared between patients with absent contractility (AC, n = 40), ineffective esophageal motility (IEM; n = 15), and normal motility (n = 19); the five remaining patients met criteria for other motility diagnoses. Groups differed in severity of skin involvement measured by the modified Rodnan skin score (0-51): AC (adjusted mean 12.6), IEM (4.4), normal (4.3), p = 0.043. Pulmonary function tests [percent predicted FVC and DLCO) were lower in AC (adjusted mean, FVC: 70.3, DLCO 51.1), than IEM (FVC: 92.0; DLCO: 76.9) and normal motility (FVC: 80.0; DLCO: 67.2), p values 0.057 (FVC) and 0.007 (DLCO). Groups did not differ by SSc-disease duration, autoantibodies, or reported symptoms of dysphagia or reflux.

CONCLUSIONS & INFERENCES

In patients with SSc, absent esophageal contractility on HRM was associated with increased skin disease severity and worse lung function. Obtaining HRM to identify SSc patients with more severe esophageal dysfunction could be considered to enable implementation of management strategies in patients potentially at risk for increased morbidity and mortality.

The Functional Lumen Imaging Probe Detects Esophageal Contractility Not Observed With Manometry in Patients With Achalasia

BACKGROUND & AIMS

The functional lumen imaging probe (FLIP) could improve the characterization of achalasia subtypes by detecting nonocclusive esophageal contractions not observed with standard manometry. We aimed to evaluate esophageal contractions during volumetric distention in patients with achalasia using FLIP topography.

METHODS

Fifty-one treatment-naive patients with achalasia, defined and subclassified by high-resolution esophageal pressure topography, and 10 asymptomatic individuals (controls) were evaluated with the FLIP during endoscopy. During stepwise distension, simultaneous intrabag pressures and 16 channels of cross-sectional areas were measured; data were exported to software that generated FLIP topography plots. Esophageal contractility was identified by noting periods of reduced luminal diameter. Esophageal contractions were characterized further by propagation direction, repetitiveness, and based on whether they were occluding or nonoccluding.

RESULTS

Esophageal contractility was detected in all 10 controls: 8 of 10 had repetitive antegrade contractions and 9 of 10 had occluding contractions. Contractility was detected in 27% (4 of 15) of patients with type I achalasia and in 65% (18 of 26, including 9 with occluding contractions) of patients with type II achalasia. Contractility was detected in all 10 patients with type III achalasia; 8 of these patients had a pattern of contractility that was not observed in controls (repetitive retrograde contractions).

CONCLUSIONS

Esophageal contractility not observed with manometry can be detected in patients with achalasia using FLIP topography. The presence and patterns of contractility detected with FLIP topography may represent variations in pathophysiology, such as mechanisms of panesophageal pressurization in patients with type II achalasia. These findings could have implications for additional subclassification to supplement prediction of the achalasia disease course.

Utilizing functional lumen imaging probe topography to evaluate esophageal contractility during volumetric distention: a pilot study

BACKGROUND

The functional lumen imaging probe (FLIP) measures luminal cross-sectional area and pressure during volumetric distension. By applying novel customized software to produce FLIP topography plots, organized esophageal contractility can be visualized and analyzed. We aimed to describe the stimulus thresholds and contractile characteristics for distension-induced esophageal body contractility using FLIP topography in normal controls.

METHODS

Ten healthy controls were evaluated during endoscopy with FLIP. During stepwise bag distension, simultaneous intra-bag pressure and luminal diameter measurements were obtained and exported to a MatLab program to generate FLIP topography plots. The distension volume, intra-bag pressure, and maximum esophageal body diameters were measured for the onset and cessation of repetitive antegrade contractions (RACs). Contraction duration, interval, magnitude, and velocity were measured at 8 and 3-cm proximal to the esophagogastric junction.

KEY RESULTS

Eight of ten subjects demonstrated RACs at a median onset volume of 29 mL (IQR: 25-38.8), median intra-bag pressure of 10.7 mmHg (IQR: 8.6-15.9), and median maximum esophageal body diameter of 18.5 mm (IQR: 17.5-19.6). Cessation of RACs occurred prior to completion of the distension protocol in three of the eight subjects exhibiting RACs. Values of the RAC-associated contractile metrics were also generated to characterize these events.

CONCLUSIONS & INFERENCES

Distension-induced esophageal contractions can be assessed utilizing FLIP topography. RACs are a common finding in asymptomatic controls in response to volume distention and have similar characteristics to secondary peristalsis and repetitive rapid swallows.

High-Resolution Manometry in Clinical Practice

High-resolution manometry (HRM) is the primary method used to evaluate esophageal motor function. Displayed and interpreted by esophageal pressure topography (EPT), HRM/ EPT provides a detailed assessment of esophageal function that is useful in the evaluation of patients with nonobstructive dysphagia and before foregut surgery. Esophageal motility diagnoses are determined systematically by applying objective metrics of esophageal sphincter and peristaltic function to the Chicago Classification of esophageal motility disorders. This article discusses HRM study, EPT interpretation, and the translation of EPT findings into clinical practice. Examples are provided to illustrate several clinical challenges.

Flow time through esophagogastric junction derived during high-resolution impedance-manometry studies: a novel parameter for assessing esophageal bolus transit

This study aimed to develop and validate a method to measure bolus flow time (BFT) through the esophagogastric junction (EGJ) using a high-resolution impedance-manometry (HRIM) sleeve. Ten healthy subjects were studied with concurrent HRIM and videofluoroscopy; another 15 controls were studied with HRIM alone. HRIM studies were performed using a 4.2-mm-outer diameter assembly with 36 pressure sensors at 1-cm intervals and 18 impedance segments at 2-cm intervals (Given Imaging, Los Angeles, CA). HRIM and fluoroscopic data from four barium swallows, two in the supine and two in the upright position, were analyzed to create a customized MATLAB program to calculate BFT using a HRIM sleeve comprising three sensors positioned at the crural diaphragm. Bolus transit through the EGJ measured during blinded review of fluoroscopy was almost identical to BFT calculated with the HRIM sleeve, with the nadir impedance deflection point used as the signature of bolus presence. Good correlation existed between videofluoroscopy for measurement of upper sphincter relaxation to beginning of flow [R = 0.97, P < 0.001 (supine) and R = 0.77, P < 0.01 (upright)] and time to end of flow [R = 0.95, P < 0.001 (supine) and R = 0.82, P < 0.01 (upright)]. The medians and interquartile ranges (IQR) of flow time though the EGJ in 15 healthy subjects calculated using the virtual sleeve were 3.5 s (IQR 2.3-3.9 s) in the supine position and 3.2 s (IQR 2.3-3.6 s) in the upright position. BFT is a new metric that provides important information about bolus transit through the EGJ. An assessment of BFT will determine when the EGJ is open and will also provide a useful method to accurately assess trans-EGJ pressure gradients during flow.

Acid and nonacid reflux monitoring

Detection of acid and nonacid reflux using esophageal reflux monitoring, which includes conventional and wireless pH monitoring and pH impedance, can be a valuable diagnostic tool when used appropriately in the assessment of patients with gastroesophageal reflux disease. Reflux monitoring may be especially helpful if a management change is desired, such as when initial or empirical treatment is ineffective. However, each of these methods has its limitations, which need to be accounted for in their clinical use. Indications, test performance, interpretation, and clinical applications of esophageal reflux monitoring, as well as their limitations, are discussed in this review.

A material isolated from human hands that attracts female mosquitoes

The residue left on glass surfaces by human hands was found to be attractive to femaleAedes aegypti (L.) andAnopheles quadrimaculatus Say mosquitoes. The material lost half of its activity in 1 hr. A solvent wash technique was developed to recover and concentrate the residuum from handled glass beads. The residuum could be recovered effectively with absolute ethanol and less effectively with several other solvents. More mosquitoes were attracted to heated than to unheated residuum, an indication of its volatility. Also, attraction of the residuum decreased with decreasing concentration or dose. Concentrated residuum collections, stored under refrigeration and tested for longevity, showed no appreciable loss of attractiveness up to 60 days of storage.

Contact sex pheromone in the tsetse flyGlossina pallidipes (Austen) Identification and Synthesis

Adult maleG. pallidipes attempted to copulate with decoys treated with a branched paraffin obtained from laboratory-reared female flies. The compound causing maximal response was isolated and identified as 13,23-dimethylpentatriacontane. The synthesized compound elicited increasing responses with increasing doses. This sex- and species-specific compound was always present in physiological amounts in females, as it increased from 2 μg at emergence to 10 μg per female at 14 days. It was present in wild-caught females from a wide geographical range.