Esophago-gastric junction findings on high resolution impedance manometry in children with esophageal atresia.

OBJECTIVES: Using high resolution impedance manometry (HRIM), this study characterized the esophago-gastric junction (EGJ) dynamics in children with esophageal atresia (EA). METHOD: Esophageal HRIM was performed in patients with EA aged less than 18 years. Objective motility patterns were analyzed, and EGJ data reported. Controls were pediatric patients without EA undergoing investigations for consideration of fundoplication surgery. RESULTS: Seventy-five patients (M:F = 43:32, median age 1 year 3 months [3 months-17 years 4 months]) completed 133 HRIM studies. The majority (64/75, 85.3%) had EA with distal tracheo-esophageal fistula. Compared with controls, liquid swallows were poorer in patients with EA, as evident by significant differences in distension pressure emptying and bolus flow time (BFT). The integrated relaxation pressure for thin liquid swallows was significantly different between EA types, as well as when comparing patients with EA with and without previous esophageal dilatations. The BFT for solid swallows was significantly different when compared with EA types. CONCLUSIONS: We have utilized HRIM in patients with EA to demonstrate abnormalities in their long-term EGJ function. These abnormalities correlate with poorer esophageal compliance and reduced esophageal peristalsis across the EGJ. Understanding the EGJ function in patients with EA will allow us to tailor long-term management to specific patients.

Mucosal impedance as a diagnostic tool for gastroesophageal reflux disease: an update for clinicians.

Mucosal impedance is a marker of esophageal mucosal integrity and a novel technique for assessing esophageal function and pathology. This article highlights its development and clinical application for gastroesophageal reflux disease (GERD), Barrett's esophagus, and eosinophilic esophagitis. A narrative review of key publications describing the development and use of mucosal impedance in clinical practice was conducted. A low mean nocturnal baseline impedance (MNBI) has been shown to be an independent predictor of response to anti-reflux therapy. MNBI predicts medication-responsive heartburn better than distal esophageal acid exposure time. Patients with equivocal evidence of GERD using conventional methods, with a low MNBI, had an improvement in symptoms following the initiation of PPI therapy compared to those with a normal MNBI. A similar trend was seen in a post fundoplication cohort. Strong clinical utility for the use of mucosal impedance in assessing eosinophilic esophagitis has been repeatedly demonstrated; however, there is minimal direction for application in Barrett's esophagus. The authors conclude that mucosal impedance has potential clinical utility for the assessment and diagnosis of GERD, particularly when conventional investigations have yielded equivocal results.

Distension contraction plots of pharyngeal/esophageal peristalsis: next frontier in the assessment of esophageal motor function.

Esophageal peristalsis consists of initial inhibition (relaxation) followed by excitation (contraction), both of which move sequentially in the aboral direction. Initial inhibition results in receptive relaxation and bolus-induced luminal distension, which allows propulsion by the contraction with minimal resistance to flow. Similar to the contraction wave, luminal distension has unique waveform characteristics in normal subjects; both are modulated by bolus volume, bolus viscosity, and posture, suggesting a possible cause-and-effect relationship between the two. Distension contraction plots in patients with dysphagia with normal bolus clearance [high-amplitude esophageal contractions (HAECs), esophagogastric junction outflow obstruction (EGJOO), and functional dysphagia (FD)] reveal two major findings: 1) unlike normal subjects, there is luminal occlusion distal to bolus during peristalsis in certain patients, i.e., with type 3 achalasia and nonobstructive dysphagia; and 2) bolus travels through a narrow lumen esophagus during peristalsis in patients with HAECs, EGJOO, and FD. Aforementioned findings indicate a relative dynamic obstruction to the bolus flow during peristalsis and reduced distensibility of esophageal wall in the bolus segment of the esophagus. We speculate that a normal or supernormal contraction wave pushing bolus against resistance is the mechanism of dysphagia sensation in significant number of patients. Representations of distension and contraction, combined with objective measures of flow timing and distensibility are complementary to the current scheme of classifying esophageal motility disorders based solely on the characteristics of contraction phase of peristalsis. Better understanding of the distensibility of the bolus-containing segment of the esophagus during peristalsis will lead to the development of novel medical and surgical therapies in the treatment of dysphagia in significant number of patients.

Evaluation of oropharyngeal deglutitive pressure dynamics in patients with Parkinson's disease.

In Parkinson's disease (PD), oropharyngeal dysphagia is common and clinically relevant. The neurophysiology of dysphagia in PD is complex and incompletely understood. The aim of the study was to determine the changes in oropharyngeal deglutitive pressure dynamics in PD and to correlate these with clinical characteristics including dysphagia and PD severity. In prospective consecutive series of 64 patients with PD [mean age: 66.9 ± 8.3 (SD)], we evaluated dysphagia severity clinically as well as with Sydney Swallow Questionnaire (SSQ) and Swallow Quality-of-Life Questionnaire (SWAL-QOL). PD severity was assessed with Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS). We used high-resolution pharyngeal impedance manometry (HRPIM) to objectively evaluate swallow function and compared data from 23 age-matched healthy controls [mean age 62.3 ± 9.1 (SD)]. Metrics assessed were upper esophageal sphincter (UES), integrated relaxation pressure (IRP), relaxation time (RT), maximum opening (MaxAdm), and pharyngeal intrabolus pressure (IBP) and pharyngeal contractility (PhCI). Mean MDS-UPDRS score was positively associated with dysphagia severity on SSQ and SWAL-QOL. HRPIM in PD compared with controls showed impaired UES relaxation parameters, with shorter RT, and elevated IRP and IBP. MaxAdm was not affected. The overall pharyngeal contractility was significantly higher in PD. Only the IBP and IRP were associated with PD severity and only IBP was significantly associated with dysphagia severity. UES dysfunction leading to increased flow resistance is common in patients with PD and correlates with dysphagia severity. Increased flow resistance may suggest impaired UES relaxation and/or impaired neuromodulation to bolus volume.NEW & NOTEWORTHY In Parkinson's disease, objective assessment of swallow function with high-resolution impedance manometry identifies upper esophageal sphincter dysfunction leading to increased flow resistance.

Pediatric Eosinophilic Esophagitis is Associated With Low Baseline Impedance.

BACKGROUND AND AIMS: Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder that requires repeat endoscopic evaluation(s) to assess response to treatment. This results in high health care costs and a procedural burden in affected children. Noninvasive alternate modalities to reassess disease activity have not been established. Low baseline impedance measured by multichannel pH impedance (pH-MII) is seen in adults with EoE, in keeping with poor mucosal integrity. We aimed to investigate the relationship between esophageal eosinophilia (or severity of eosinophilic infiltration) and baseline impedance in children with EoE. METHODS: We retrospectively identified 15 children diagnosed with EoE at our institution who had undergone pH-MII within 30 days of 3-level esophageal biopsy. This group were not concurrently prescribed proton pump inhibitors and had negligible reflux parameters on pH-MII. Average impedance baseline was calculated upper, mid, and lower esophageal segments via baseline impedance automated analysis (RIAA) and mean nocturnal baseline impedance (MNBI) methods. Eosinophil count data for upper, mid, and lower esophageal segments in the EoE group was collated. RESULTS: A significantly lower baseline impedance was seen across the esophageal length in children with EoE, compared with 30 controls who had no differences in age or reflux burden on nonparametric testing. A relationship between baseline impedance and eosinophil number at corresponding esophageal segments was not established. CONCLUSIONS: Baseline impedance may be an important, less invasive adjunct in clinical practice to monitor treatment response in children with EoE. Larger prospective cohort studies should delineate optimally predictive baseline impedance thresholds for active and inactive disease.

Management of Gastroesophageal Reflux Disease in Esophageal Atresia Patients: A Cross-Sectional Survey amongst International Clinicians.

OBJECTIVES: After surgical repair, up to 70% of esophageal atresia (EA) patients suffer from gastroesophageal reflux disease (GERD). The ESPGHAN/NASPGHAN guidelines on management of gastrointestinal complications in EA patients were published in 2016. Yet, the implementation of recommendations on GERD management remains poor.We aimed to assess GERD management in EA patients in more detail, to identify management inconsistencies, gaps in current knowledge, and future directions for research. METHODS: A digital questionnaire on GERD management in EA patients was sent to all members of the ESPGHAN EA working group and members of the International network of esophageal atresia (INoEA). RESULTS: Forty responses were received. Thirty-five (87.5%) clinicians routinely prescribed acid suppressive therapy for 1-24 (median 12) months. A fundoplication was considered by 90.0% of clinicians in case of refractory GERD with persistent symptoms despite maximal acid suppressive therapy and in 92.5% of clinicians in case of GERD with presence of esophagitis on EGD. Half of clinicians referred patients with recurrent strictures or dependence on transpyloric feeds. Up to 25.0% of clinicians also referred all long-gap EA patients for fundoplication, those with long-term need of acid suppressants, recurrent chest infections and feedings difficulties. CONCLUSIONS: Respondents' opinions on the optimal duration for routine acid suppressive therapy and indications for fundoplication in EA patients varied widely. To improve evidence-based care for EA patients, future prospective multicenter outcome studies should compare different diagnostic and treatment regimes for GERD in patients with EA. Complications of therapy should be one of the main outcome measures in such trials.

Quality of Life Outcomes in Primary Caregivers of Children with Esophageal Atresia.

OBJECTIVE: To investigate the quality of life (QoL) impact on primary caregivers of children with esophageal atresia. STUDY DESIGN: We used a prospective cohort study design, inviting primary caregivers of children with esophageal atresia to complete the following questionnaires: Parent Experience of Child Illness (PECI), Patient-Reported Outcomes Measurement Information System (PROMIS) Anxiety, PROMIS Depression, 12-Item Short Form Survey (SF-12), and Pediatric Quality of Life Inventory (PedsQL). The PECI, PROMIS Anxiety and Depression, and SF-12 assessed caregiver QoL, and the PedsQL assessed patient QoL. Patients with Gross type E esophageal atresia served as controls. RESULTS: The primary caregivers of 100 patients (64 males, 36 females; median age, 4.6 years; range, 3.5 months to 19.0 years) completed questionnaires. The majority (76 of 100) of patients had Gross type C esophageal atresia. A VACTERL (vertebral anomalies, anorectal malformation, cardiac anomalies, tracheoesophageal fistula, renal anomalies, limb anomalies) association was found in 30, ≥1 esophageal dilatation was performed in 57, and fundoplication was performed in 11/100. When stratified by esophageal atresia types, significant differences were found in 2 PECI subscales (unresolved sorrow/anger, P = .02; uncertainty, P = .02), in PROMIS Anxiety (P = .02), and in SF-12 mental health (P = .02) and mental component summary scores (P = .02). No significant differences were found for VACTERL association, nor esophageal dilatation. Requirement for fundoplication resulted in lower SF-12 general health score, and lower PedsQL social and physical functioning scores. CONCLUSIONS: We have demonstrated that caring for a child with esophageal atresia and a previous requirement for fundoplication impacts caregiver QoL.

Radiation burden in patients with esophageal atresia: a systematic review.

Esophageal atresia (EA) is the most common congenital esophageal disorder. Radiological imaging facilitates diagnosis, surgical interventions, and follow-up. Despite this, standardized monitoring guidelines are lacking. We aimed to: (1) review the literature regarding radiation burden in children with EA; (2) establish the presence of guidelines for diagnosis and follow-up in children with EA. The systematic review was performed according to PRISMA protocol. Two investigators conducted independent searches (PubMed, Ovid, Cochrane Review) and data extraction. Analysis focused on pre- and post-operative imaging type and frequency to determine the radiation burden. Seven studies met the inclusion criteria (337 patients). All authors agreed upon the need to minimize radiation burden, recommending symptoms-guided management, use of dosimeters, and non-radiating imaging. One study identified a median 130-fold increase in cumulative lifetime cancer risk in children with EA compared with other babies in the special care unit. The most common investigations were X-ray and CT (pre-operatively), and X-ray and contrast swallow (post-operatively). Standardized guidelines focused upon the frequency and type of radiological imaging for children with EA are lacking. Children with EA are subjected to more radiation exposure than the general population. Implementation of non-radiating imaging (ultrasonography, manometry) is recommended.

Changes in specific esophageal neuromechanical wall states are associated with conscious awareness of a solid swallowed bolus in healthy subjects.

Esophageal neuromechanical wall states are the physical manifestations of circular muscle inhibition and contraction resulting from neural inputs and leading to bolus propulsion. A novel method infers esophageal neuromechanical wall states through simultaneous determination of pressure and diameter in vivo using impedance manometry. We hypothesized that changes in esophageal neuromechanical wall states relate to conscious awareness of esophageal bolus passage ("bolus perception"). Seven healthy participants were selected for perception of solid bolus passage and were compared with seven healthy participants with no conscious awareness of solid bolus passage. Participants were studied using impedance manometry (MMS Solar, Unisensor, 20 Hz). Subjects swallowed ten 5-ml liquid and ten 2-cm square saline-soaked bread boluses and rated bolus perception using a visual analog scale. Esophageal neuromechanical wall states were calculated and analyzed. Proportions of time spent in states with and without luminal distension were compared using a two-proportions Z-test. Bolus perception was associated with neuromechanical wall states corresponding to luminal distension more frequently than matching states without distension in the proximal esophagus (P < 0.001) and transition zone (P < 0.001), whereas there were no differences for the distal esophagus. In healthy volunteers, perceived swallows relate to changes in esophageal neuromechanical wall states in the proximal esophagus. We postulate that these changes relate to bolus retention and summation of active and passive wall tension activating intramural tension receptors.NEW & NOTEWORTHY This study explores esophageal neuromechanical wall states derived from changes in pressure and impedance-derived distension in relation to conscious awareness of esophageal solid bolus transit in healthy volunteers. There are increases in neuromechanical wall states indicative of esophageal distension in healthy volunteers with conscious awareness of bolus transit as compared with unaware individuals. Bolus-based esophageal distension is postulated as a mechanism for esophageal symptoms such as dysphagia.

What is the role of high-resolution oesophageal manometry in paediatrics?

Abnormal oesophageal motility may impair oesophageal bolus transport leading to symptoms of chest pain and regurgitation. Oesophageal pathophysiology may include neuromuscular and/or structural defects leading to weak, incoordinate or absent peristalsis and impaired oesophago-gastric junction relaxation. Understanding these mechanisms is important to determine the appropriate course of therapy. Whilst, barium oesophagram is the mainstay for clinical investigation of oesophageal motility, high-resolution manometry is now more widely available. This review describes the potential value of high-resolution manometry in paediatric gastroenterology practise.

High-Resolution Pharyngeal Manometry and Impedance: Protocols and Metrics-Recommendations of a High-Resolution Pharyngeal Manometry International Working Group.

High-resolution manometry has traditionally been utilized in gastroenterology diagnostic clinical and research applications. Recently, it is also finding new and important applications in speech pathology and laryngology practices. A High-Resolution Pharyngeal Manometry International Working Group was formed as a grass roots effort to establish a consensus on methodology, protocol, and outcome metrics for high-resolution pharyngeal manometry (HRPM) with consideration of impedance as an adjunct modality. The Working Group undertook three tasks (1) survey what experts were currently doing in their clinical and/or research practice; (2) perform a review of the literature underpinning the value of particular HRPM metrics for understanding swallowing physiology and pathophysiology; and (3) establish a core outcomes set of HRPM metrics via a Delphi consensus process. Expert survey results were used to create a recommended HRPM protocol addressing system configuration, catheter insertion, and bolus administration. Ninety two articles were included in the final literature review resulting in categorization of 22 HRPM-impedance metrics into three classes: pharyngeal lumen occlusive pressures, hypopharyngeal intrabolus pressures, and upper esophageal sphincter (UES) function. A stable Delphi consensus was achieved for 8 HRPM-Impedance metrics: pharyngeal contractile integral (CI), velopharyngeal CI, hypopharyngeal CI, hypopharyngeal pressure at nadir impedance, UES integrated relaxation pressure, relaxation time, and maximum admittance. While some important unanswered questions remain, our work represents the first step in standardization of high-resolution pharyngeal manometry acquisition, measurement, and reporting. This could potentially inform future proposals for an HRPM-based classification system specifically for pharyngeal swallowing disorders.

Clinical Management of Pediatric Achalasia: A Survey of Current Practice.

OBJECTIVES: Pediatric achalasia is a rare neurodegenerative disorder of the esophagus that requires treatment. Different diagnostic and treatment modalities are available, but there are no data that show how children can best be diagnosed and treated. We aimed to identify current practices regarding the diagnostic and therapeutic approach toward children with achalasia. METHODS: Information on the current practice regarding the management of pediatric achalasia was collected by an online-based survey sent to members of the European and North American Societies for Pediatric Gastroenterology Hepatology and Nutrition involved in pediatric achalasia care. RESULTS: The survey was completed by 38 centers from 24 countries. Within these centers, 108 children were diagnosed with achalasia in the last year (median 2, range 0-15). Achalasia was primarily managed by a pediatric gastroenterologist (76%) and involved a multidisciplinary team in 84% of centers, also including a surgeon (87%), radiologist (61%), dietician (37%), speech pathologist (8%), and psychologist (5%). Medical history taking and physical examination were considered most important to establish the diagnosis (50%), followed by (a combination of) manometry (45%) or contrast swallow (21%). Treatment of first choice was Heller myotomy (58%), followed by pneumatic dilation (46%) and peroral endoscopic myotomy (29%). CONCLUSION: This study shows a great heterogeneity in the management of pediatric achalasia amongst different centers worldwide. These findings stress the need for well-designed intervention trials in children with achalasia. Given the rarity of this disease, we recommend that achalasia care should be managed in centers with access to appropriate diagnostic and treatment modalities.

Novel Pressure-Impedance Parameters for Evaluating Esophageal Function in Pediatric Achalasia.

OBJECTIVE: In achalasia, absent peristalsis and reduced esophagogastric junction (EGJ) relaxation and compliance underlie dysphagia symptoms. Novel high-resolution impedance manometry variables, that is, bolus presence time (BPT) and trans-EGJ-bolus flow time (BFT) have been developed to estimate the duration of EGJ opening and trans-EGJ bolus flow. The aim of this study was to evaluate esophageal motor function and bolus flow in children diagnosed with achalasia using these variables. METHODS: High-resolution impedance manometry recordings from 20 children who fulfilled the Chicago Classification (V3) criteria for achalasia were compared with recordings of 15 children with normal esophageal high-resolution manometry findings and no other evidence suggestive of achalasia. Matlab-based analysis software was used to calculate BPT and BFT. RESULTS: Both BPT and BFT were significantly reduced in achalasia patients compared with children with normal esophageal motility (BPT 3.3 s vs 5.1 s P < 0.01; BFT 1.4 s vs 4.3 s P < 0.001). BFT was significantly lower than BPT (achalasia difference 1.9 s ±â€Š1.3 s, P = 0.001 and normal difference 0.9 ±â€Š0.3 s, P = 0.001). Overall, there was a significant correlation between BPT and BFT (r = 0.825, P < 0.001). We observed a 2-way differentiation of achalasia patients; those in whom the BPT and BFT were proportional, but significantly lower than in patients with normal peristalsis, and those in whom BFT was disproportionately lower than BPT. CONCLUSIONS: Calculation of BPT and BFT may help determine whether esophageal bolus transport to the EGJ and/or esophageal emptying through the EGJ are aberrant. For achalasia, this may detect flow resistance at the EGJ, potentially improving both diagnosis and objective assessment of therapeutic effects.

Modulation of Upper Esophageal Sphincter (UES) Relaxation and Opening During Volume Swallowing.

UES opening occurs following cricopharyngeus deactivation and submental muscle contraction causing hyolaryngeal elevation and UES distraction. During impedance manometry, the inverse of impedance (admittance) can be used to measure bolus presence and infer UES opening. We hypothesized that the temporal relationship between UES relaxation, opening and hyolaryngeal elevation would change with increasing bolus volume. Simultaneous intramuscular cricopharyngeal (CP) electromyography (EMG), surface submental EMG (SM-EMG), and high-resolution impedance manometry were recorded in eight (aged 27 ± 7 years, 5 M) healthy volunteers, while swallowing 0.9 % saline boluses of 2, 5, 10, and 20 ml. Data were exported and analyzed via Matlab. Statistical analysis comprised repeated measures one-way ANOVA and Pearson correlation. A P value of <0.05 was considered significant. Duration of CP deactivation increased at 20 ml volume (P < 0.001). UES relaxation and opening increased with increasing bolus volume (P < 0.001); however, overall duration of SM activation did not change. As UES opening occurs progressively earlier with increasing volumes, peak SM-EMG activity occurs relatively later (P < 0.001) and shifts from occurring before to following peak UES distention. During healthy swallowing, there is sensory modulation of cricopharyngeal and submental muscle activity. Intrabolus pressures, transmitted from the tongue base and pharynx, play a progressively more important role in sphincter opening with increasing volume. The findings may explain why some healthy elderly and patients with oropharyngeal dysphagia have difficulty swallowing larger while tolerating smaller bolus volumes.

Predicting the activation states of the muscles governing upper esophageal sphincter relaxation and opening.

The swallowing muscles that influence upper esophageal sphincter (UES) opening are centrally controlled and modulated by sensory information. Activation and deactivation of neural inputs to these muscles, including the intrinsic cricopharyngeus (CP) and extrinsic submental (SM) muscles, results in their mechanical activation or deactivation, which changes the diameter of the lumen, alters the intraluminal pressure, and ultimately reduces or promotes flow of content. By measuring the changes in diameter, using intraluminal impedance, and the concurrent changes in intraluminal pressure, it is possible to determine when the muscles are passively or actively relaxing or contracting. From these "mechanical states" of the muscle, the neural inputs driving the specific motor behaviors of the UES can be inferred. In this study we compared predictions of UES mechanical states directly with the activity measured by electromyography (EMG). In eight subjects, pharyngeal pressure and impedance were recorded in parallel with CP- and SM-EMG activity. UES pressure and impedance swallow profiles correlated with the CP-EMG and SM-EMG recordings, respectively. Eight UES muscle states were determined by using the gradient of pressure and impedance with respect to time. Guided by the level and gradient change of EMG activity, mechanical states successfully predicted the activity of the CP muscle and SM muscle independently. Mechanical state predictions revealed patterns consistent with the known neural inputs activating the different muscles during swallowing. Derivation of "activation state" maps may allow better physiological and pathophysiological interpretations of UES function.

Pressure-flow characteristics of normal and disordered esophageal motor patterns.

OBJECTIVE: To perform pressure-flow analysis (PFA) in a cohort of pediatric patients who were referred for diagnostic manometric investigation. STUDY DESIGN: PFA was performed using purpose designed Matlab-based software. The pressure-flow index (PFI), a composite measure of bolus pressurization relative to flow and the impedance ratio, a measure of the extent of bolus clearance failure were calculated. RESULTS: Tracings of 76 pediatric patients (32 males; 9.1 ± 0.7 years) and 25 healthy adult controls (7 males; 36.1 ± 2.2 years) were analyzed. Patients mostly had normal motility (50%) or a category 4 disorder and usually weak peristalsis (31.5%) according to the Chicago Classification. PFA of healthy controls defined reference ranges for PFI ≤142 and impedance ratio ≤0.49. Pediatric patients with pressure-flow (PF) characteristics within these limits had normal motility (62%), most patients with PF characteristics outside these limits also had an abnormal Chicago Classification (61%). Patients with high PFI and disordered motor patterns all had esophagogastric junction outflow obstruction. CONCLUSIONS: Disordered PF characteristics are associated with disordered esophageal motor patterns. By defining the degree of over-pressurization and/or extent of clearance failure, PFA may be a useful adjunct to esophageal pressure topography-based classification.

High-resolution manometry combined with impedance measurements discriminates the cause of dysphagia in children.

Pressure-flow analysis allows assessing esophageal bolus transport in relation to esophageal pressures. This study aimed to characterize pressure-flow metrics in relation to dysphagia in paediatric patients. We analysed esophageal pressure-impedance recordings of 5 ml liquid and viscous swallows from 35 children (17 M, mean 10.5 ± 0.8 years). Primary indication for referral was gastroesophageal reflux disease (GERD) (9), post-fundoplication dysphagia (5), idiopathic dysphagia (16), trachea-esophageal fistula (2) and other (3). Peristaltic function was assessed using the 20 mmHg iso-contour defect and the timing between bolus pressure and flow was assessed using the Pressure Flow Index, a metric elevated in relation to dysphagia. Patients were stratified in relation to dysphagia and to peristaltic defect size. Dysphagia was characterized by a weaker peristalsis for liquids and higher Pressure Flow Index for viscous. When patients were stratified based on weak or normal peristalsis, dysphagia with weak peristalsis related to a larger iso-contour defect size and dysphagia with normal peristalsis related to higher Pressure Flow Index. CONCLUSION: Pressure-flow analysis enables differentiation of patients with dysphagia due to weak peristalsis (poor bolus clearance) from abnormal bolus flow resistance (esophageal outflow obstruction). This new dichotomous categorization of esophageal function may help guide the selection of optimal treatment such as pharmacological or endoscopic therapy. WHAT IS KNOWN: • Pressure-flow analysis (PFA) can detect abnormalities in esophageal motility using integrated analysis of bolus propulsion and bolus flow during swallowing. • AIM analysis has recently been reported to be useful in identifying subtle pre-operative esophageal dysfunction in adult patients who developed post-fundoplication dysphagia as well as in patients with non-obstructive dysphagia. WHAT IS NEW: • Pressure-flow parameters can distinguish the cause of dysphagia in paediatric patients. • Combined high-resolution manometry and impedance measurements with pressure-flow analysis can differentiate paediatric patients with dysphagia symptoms in relation to either weak peristalsis (poor bolus clearance) or over-pressurization (abnormal bolus flow resistance). HOW MIGHT IT IMPACT ON CLINICAL PRACTICE IN THE FUTURE? • This study supports the use of a novel objective analysis method on recordings that are readily used in paediatric clinical practice. • The pressure-flow approach allows discriminating esophageal dysfunction in relation to dysphagia symptoms in children. This has not been achieved in children with current analysis methods. • The new findings of this study allow a dichotomous categorization of esophageal function, which may help to guide the selection of the most optimal treatment such as pharmacological or endoscopic therapy.

Gastroesophageal reflux, esophageal function, gastric emptying, and the relationship to dysphagia before and after antireflux surgery in children.

OBJECTIVES: To assess gastroesophageal reflux (GER), esophageal motility, and gastric emptying in children before and after laparoscopic fundoplication and to identify functional measures associated with postoperative dysphagia. STUDY DESIGN: Combined impedance-manometry, 24-hour pH-impedance, and gastric-emptying breath tests were performed before and after laparoscopic anterior partial fundoplication. Impedance-manometry studies were analyzed with the use of conventional analysis methods and a novel automated impedance manometry (AIM) analysis. RESULTS: Children with therapy resistent GER disease (n = 25) were assessed before fundoplication, of whom 10 (median age 6.4 years; range, 1.1-17.1 years; 7 male; 4 with neurologic impairment) underwent fundoplication. GER episodes reduced from 97 (69-172) to 66 (18-87)/24 hours (P = .012). Peristaltic contractions were unaltered. Complete lower esophageal sphincter relaxations decreased after fundoplication (92% [76%-100%] vs 65% [29%-91%], P = .038). Four (40%) patients developed postoperative dysphagia, which was transient in 2. In those patients, preoperative gastric emptying was delayed compared with patients without postoperative dysphagia, 96 minutes (71-104 minutes) versus 48 minutes (26-68 minutes), P = .032, and AIM analysis derived dysphagia risk index was greater (56 [15-105] vs 2 [2-6] P = .016). Two patients underwent a repeat fundoplication. DISCUSSION: Fundoplication in children reduced GER without altering esophageal motility. Four patients who developed dysphagia demonstrated slower gastric emptying and greater dysplasia risk index preoperatively. AIM analysis may allow detection of subtle esophageal abnormalities potentially leading to postoperative dysphagia.

Characterization of esophageal pressure-flow abnormalities in patients with non-obstructive dysphagia and normal manometry findings.

BACKGROUND AND AIM: Patients with non-obstructive dysphagia (NOD) report symptoms of impaired esophageal bolus transit without evidence of bolus stasis. In such patients, manometric investigation may diagnose esophageal motility disorders; however, many have normal motor patterns. We hypothesized that patients with NOD would demonstrate evidence of high flow-resistance during bolus passage which in turn would relate to the reporting of bolus hold up perception. METHODS: Esophageal pressure-impedance recordings of 5 mL liquid and viscous swallows from 18 NOD patients (11 male; 19-71 years) and 17 control subjects (9 male; 25-60 years) were analyzed. The relationship between intrabolus pressure and bolus flow timing in the esophagus was assessed using the pressure flow index (PFI). Bolus perception was assessed swallow by swallow using standardized descriptors. RESULTS: NOD patients were characterized by a higher PFI than controls. The PFI defined a pressure-flow abnormality in all patients who appeared normal based on the assessment esophageal motor patterns and bolus clearance. The PFI was higher for individual swallows during which subjects reported perception of bolus passage. CONCLUSION: Bolus flow-resistance is higher in NOD patients compared with controls as well as higher in relation to perception of bolus transit, suggesting the presence of an esophageal motility disorder despite normal findings on conventional analysis.

Outcomes of endoscopy and novel pH-impedance parameters in children: is there a correlation?

OBJECTIVES: Discordance exists between outcomes of endoscopy, multichannel intraluminal impedance monitoring (pH-MII), MII baselines, and gastroesophageal reflux symptoms. The aim of the present study was to determine the association between endoscopy, pH-MII and MII baselines, in children with gastroesophageal reflux symptoms. METHODS: Endoscopies were graded for reflux esophagitis (RE). Biopsies of the distal esophagus were assessed for signs suggestive of esophagitis. Reflux index (RI), symptom association probability (SAP), number of reflux episodes, and mean baseline values were calculated. pH-MII was considered positive in children when RI was ≥ 3% and/or SAP was ≥ 95% and for infants when RI was ≥ 10% and/or SAP was ≥ 95%. Baselines were manually calculated and compared with an automated analysis. For MII baselines, patients were divided in 3 groups: normal endoscopy and negative overall pH-MII; normal endoscopy and an overall positive pH-MII; and RE. RESULTS: A total of 26 children and 14 infants were included, median age: 26.5 months (2 months-16.2 years). Thirteen (32.5%) had RE. A significant negative association was found for RI and MII baselines (P = 0.009) and between SAP and RE (P = 0.039, odds ratio 1.018). MII baseline values were predictive for neither conventional pH-MII parameters nor RE. Manual analysis and automated calculation of MII baselines showed a perfect correlation. Distal MII baselines were significantly lower in children with a positive overall pH-MII outcome compared with the proximal esophagus (P = 0.049). No significant changes were found in baselines among the different groups 1 to 3. CONCLUSIONS: Acid-related parameters are significantly related to MII baselines. A perfect correlation between manual- and automated analysis of MII baselines was found. Large prospective studies are needed to confirm the exact role of endoscopy and MII baselines.