New insights into pharyngo-esophageal bolus transport revealed by pressure-impedance measurement

Author version made available in accordance with the publisher's policy.Introduction: Pharyngeal propulsion, strength of peristalsis and esophago-gastric junction (EJG) resistance are determinants of esophageal bolus transport. This study used pressure-impedance methods to correlate pharyngo-esophageal function with the esophageal bolus trajectory pathway and pressures generated during bolus transport. Methods: Pharyngo-esophageal pressure-impedance measurements were performed in 20 healthy adult controls. Pharyngeal automated impedance manometry was performed to derive pharyngeal swallow function variables. The esophageal time of nadir impedance (TZn) was used to track bolus trajectory pathway. The inflexion, or flow stasis point (FSP), of the trajectory curve was determined as were the pressures within the bolus (PZn) above and below the FSP. The size of 20mmHg isocontour defect measured the integrity of the peristaltic wave. Results: For viscous boluses, weaker pharyngeal bolus propulsion correlated with the FSP being located higher in the esophagus. Pressure within the bolus was observed to increase at the FSP and below the FSP in a manner that correlated with the magnitude of esophageal peak pressures. Larger 20mmHg isocontour defects were associated with lower pressures within the bolus at the FSP and below. Conclusion: The FSP of the bolus trajectory pathway appears to represent a switch from bolus propulsion due to pharyngeal mechanisms to bolus propulsion due to esophageal mechanisms. 20mmHg isocontour defects significantly reduce bolus driving pressure at or below the FSP

Oesophageal pressure-flow metrics in relation to bolus volume, bolus consistency and bolus perception

Author version made available in accordance with the publisher's policy.The utility of combined oesophageal pressure–impedance recording has been enhanced by automation of data analysis. To understand how oesophageal function as measured by automated impedance manometry (AIM) pressure-flow analysis varies with bolus characteristics and subjective perception of bolus passage. Oesophageal pressure–impedance recordings of 5 and 10 ml liquid or viscous swallows and 2 and 4 cm solid swallows from 20 healthy control subjects (five male; 25–73 years) were analysed. Metrics indicative of bolus pressurization (intrabolus pressure and intrabolus pressure slope) were derived. Bolus flow resistance, the relationship between bolus pressurization and flow timing, was assessed using a pressure-flow index. Bolus retention was assessed using the ratio of nadir impedance to peak pressure impedance (impedance ratio). Subjective perception of bolus passage was assessed swallow by swallow. Viscosity increased the bolus flow resistance and reduced bolus clearance. Responses to boluses of larger volume and more viscous consistency revealed a positive correlation between bolus pressurization and oesophageal peak pressure. Flow resistance was higher in subjects who perceived bolus hold up of solids. Bolus volume and bolus type alter oesophageal function and impact AIM analysis metrics descriptive of oesophageal function. Perception of bolus transit was associated with heightened bolus pressurization relative to bolus flow

Objective Prediction of Pharyngeal Swallow Dysfunction in Dysphagia through Artificial Neural Network Modelling

This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving'. © 2016 John Wiley & Sons LtdBackground Pharyngeal pressure-flow analysis (PFA) of high resolution impedance-manometry (HRIM) with calculation of the swallow risk index (SRI) can quantify swallow dysfunction predisposing to aspiration. We explored the potential use of artificial neural networks (ANN) to model the relationship between PFA swallow metrics and aspiration and to predict swallow dysfunction. Methods Two hundred consecutive dysphagia patients referred for videofluoroscopy and HRIM were assessed. Presence of aspiration was scored and PFA software derived 13 metrics and the SRI. An ANN was created and optimized over training cycles to achieve optimal classification accuracy for matching inputs (PFA metrics) to output (presence of aspiration on videofluoroscopy). Application of the ANN returned a value between 0.00 and 1.00 reflecting the degree of swallow dysfunction. Key Results Twenty one patients were excluded due to insufficient number of swallows (<4). Of 179, 58 aspirated and 27 had aspiration pneumonia history. The SRI was higher in aspirators (aspiration 24 [9, 41] vs no aspiration 7 [2, 18], p < 0.001) and patients with pneumonia (pneumonia 27 [5, 42] vs no pneumonia 8 [3, 24], p < 0.05). The ANN Predicted Risk was higher in aspirators (aspiration 0.57 [0.38, 0.82] vs no aspiration 0.13 [0.4, 0.25], p < 0.001) and in patients with pneumonia (pneumonia 0.46 [0.18, 0.60] vs no pneumonia 0.18 [0.6, 0.49], p < 0.01). Prognostic value of the ANN was superior to the SRI. Conclusions & Inferences In a heterogeneous cohort of dysphagia patients, PFA with ANN modeling offers enhanced detection of clinically significant swallowing dysfunction, probably more accurately reflecting the complex interplay of swallow characteristics that causes aspiration

Whey- vs Casein-Based Enteral Formula and Gastrointestinal Function in Children With Cerebral Palsy.

Objectives: Children with severe cerebral palsy (CP) commonly have gastrointestinal (GI) dysfunction. Whey-based enteral formulas have been postulated to reduce gastroesophageal reflux (GOR) and accelerate gastric emptying (GE). The authors investigated whether whey-based (vs casein-based) enteral formulas reduce GOR and accelerate GE in children who have severe CP with a gastrostomy and fundoplication. Methods: Thirteen children received a casein-based formula for 1 week and either a 50% whey whole protein (50% WWP) or a 100% whey partially hydrolyzed protein (100% WPHP) formula for 1 week. Reflux episodes, gastric half-emptying time (GE t1/2), and reported pain and GI symptoms were measured. Results: Whey formulas emptied significantly faster than casein (median [interquartile range (IQR)] GE t1/2, 33.9 [25.3-166.2] min vs 56.6 [46-191] min; P = .033). Reflux parameters were unchanged. GI symptoms were lower in children who received 50% WWP (visual analog symptom score, median [IQR], 0[0-11.8]) vs 100% WPHP (13.0 [2.5-24.8]) (P = .035). Conclusion: This pilot study shows that in children who have severe CP with a gastrostomy and fundoplication, GE of the whey-based enteral formula is significantly faster than casein. The acceleration in GE does not alter GOR frequency, and there appears to be no effect of whey vs casein in reducing acid, nonacid, and total reflux episodes. The results indicate that enteral formula selection may be particularly important for children with severe CP and delayed GE. (JPEN J Parenter Enteral Nutr. 2012;36:118S-123S

Maximum Upper Esophageal Sphincter (UES) Admittance: A Non-Specific Marker of UES Dysfunction

This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving'.© 2015 John Wiley & Sons LtdBackground Assessment of upper esophageal sphincter (UES) motility is challenging, as functionally, UES relaxation and opening are distinct. We studied novel parameters, UES admittance (inverse of nadir impedance), and 0.2-s integrated relaxation pressure (IRP), in patients with cricopharyngeal bar (CPB) and motor neuron disease (MND), as predictors of UES dysfunction. Methods Sixty-six healthy subjects (n = 50 controls 20–80 years; n = 16 elderly >80 years), 11 patients with CPB (51–83 years) and 16 with MND (58–91 years) were studied using pharyngeal high-resolution impedance manometry. Subjects received 5 × 5 mL liquid (L) and viscous (V) boluses. Admittance and IRP were compared by age and between groups. A p < 0.05 was considered significant. Key Results In healthy subjects, admittance was reduced (L: p = 0.005 and V: p = 0.04) and the IRP higher with liquids (p = 0.02) in older age. Admittance was reduced in MND compared to both healthy groups (Young: p < 0.0001 for both, Elderly L: p < 0.0001 and V: p = 0.009) and CPB with liquid (p = 0.001). Only liquid showed a higher IRP in MND patients compared to controls (p = 0.03), but was similar to healthy elderly and CPB patients. Only admittance differentiated younger controls from CPB (L: p = 0.0002 and V: p < 0.0001), with no differences in either parameter between CPB and elderly subjects. Conclusions & Inferences The effects of aging and pathology were better discriminated by UES maximum admittance, demonstrating greater statistical confidence across bolus consistencies as compared to 0.2-s IRP. Maximum admittance may be a clinically useful determinate of UES dysfunction

Pressure-Flow Characteristics of Normal and Disordered Esophageal Motor Patterns

Copyright © 2015 Elsevier Inc. All rights reserved This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/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

Laparoscopic Adjustable Gastric Banding in Australian adolescents: Should it be done?

“This is a post-peer-review, pre-copyedit version of an article published in Obesity Surgery. The final authenticated version is available online at: http://dx.doi.org/10.1007/s11695-017-2544-6”.Objective There are very few studies on laparoscopic adjustable gastric banding (LAGB) in obese adolescents with follow up for more than 36 months, let alone good prospective data beyond 24 months in Australian adolescents. We aimed to evaluate medium term (>36 months) safety and efficacy of LAGB in adolescents with severe obesity. Methods This is a prospective cohort study (March 2009–December 2015) in one tertiary referral hospital including obese adolescents (14–18 years) with a body mass index (BMI) >40 (or ≥35 with comorbidities) who consented to have LAGB. Exclusion criteria were syndromal causes of obesity, depression and oesophageal motility disorders. Main outcome measures include change in weight and BMI at 6, 12, 24, 36 and 48 months post LAGB; postoperative complications; and admissions. Results Twenty-one adolescents (median [interquartile range (IQR)] 17.4 [16.5–17.7] years, 9 males, mean ± SD BMI 47.3 ± 8.4 kg/m2) had a median follow up of 45.5 [32–50] months post LAGB. Follow up data were available for 16 adolescents. Weight and BMI improved significantly at all follow up times (all p < 0.01). The median maximum BMI loss was 10 [7.1–14.7] kg/m2. There were four minor early complications. Seven bands were removed due to weight loss failure/regain (two had also obstructive symptoms). Conclusions We have shown in the longest prospective LAGB postoperative follow up study of Australian adolescents that LAGB improves BMI in the majority of adolescents without significant comorbidities. LAGB is still a reasonable option to be considered as a temporary procedure to manage severe obesity during adolescence

Impaired bolus clearance in asymptomatic older adults during high resolution impedance manometry

12892This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving. This author accepted manuscript is made available following 12 month embargo from date of publication (26 June 2016) in accordance with the publisher's copyright policy.Background Dysphagia becomes more common in old age. We performed high-resolution impedance manometry (HRIM) in asymptomatic healthy adults (including an older cohort >80 years) to assess HRIM findings in relation to bolus clearance. Methods Esophageal HRIM was performed in a sitting posture in 45 healthy volunteers (n = 30 young control, mean age 37 ± 11 years and n = 15 older subjects aged 85 ± 4 years) using a 3.2-mm solid-state catheter (Solar GI system; MMS, Enschede, The Netherlands) with 25 pressure (1-cm spacing) and 12 impedance segments (2-cm intervals). Five swallows each of 5- and 10-mL liquid and viscous bolus were performed and analyzed using esophageal pressure topography metrics and Chicago classification criteria as well as pressure-flow parameters. Bolus transit was determined using standard impedance criteria. A p-value <0.05 was considered significant. Key Results Impaired bolus clearance occurred more frequently in asymptomatic older subjects compared with young controls (YC) during liquid (40 vs 18%, χ2 = 4.935; p < 0.05) and viscous (60 vs 17%; χ2 = 39.08; p < 0.001) swallowing. Longer peristaltic breaks (p < 0.05) and more rapid peristalsis (L: p < 0.004, V: p = 0.003) occurred in the older cohort, with reduced impedance-based clearance for both bolus consistencies (L: p < 0.05, V: p < 0.001). Decreased peristaltic vigor (distal contractile integral <450 mmHg/s/cm) was associated with reduced liquid clearance in both age groups (p < 0.001) and of viscous swallows in the older group (p < 0.001). Impedance ratio, a marker of bolus retention, was increased in older subjects during liquid (p = 0.002) and viscous (p < 0.001) swallowing. Conclusions & Inferences Impaired liquid and viscous bolus clearance, esophageal pressure topography, and pressure-flow changes were seen in asymptomatic older subjects

Age-related impairment of esophagogastric junction relaxation and bolus flow time

Distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/AIM To investigate the functional effects of abnormal esophagogastric (EGJ) measurements in asymptomatic healthy volunteers over eighty years of age. METHODS Data from 30 young controls (11 M, mean age 37 ± 11 years) and 15 aged subjects (9 M, 85 ± 4 years) were compared for novel metrics of EGJ-function: EGJ-contractile integral (EGJ-CI), “total” EGJ-CI and bolus flow time (BFT). Data were acquired using a 3.2 mm, 25 pressure (1 cm spacing) and 12 impedance segment (2 cm) solid-state catheter (Unisensor and MMS Solar GI system) across the EGJ. Five swallows each of 5 mL liquid (L) and viscous (V) bolus were analyzed. Mean values were compared using Student’s t test for normally distributed data or Mann Whitney U-test when non-normally distributed. A P value < 0.05 was considered significant. RESULTS EGJ-CI at rest was similar for older subjects compared to controls. “Total” EGJ-CI, measured during liquid swallowing, was increased in older individuals when compared to young controls (O 39 ± 7 mmHg.cm vs C 18 ± 3 mmHg.cm; P = 0.006). For both liquid and viscous bolus consistencies, IRP4 was increased (L: 11.9 ± 2.3 mmHg vs 5.9 ± 1.0 mmHg, P = 0.019 and V: 14.3 ± 2.4 mmHg vs 7.3 ± 0.8 mmHg; P = 0.02) and BFT was reduced (L: 1.7 ± 0.3 s vs 3.8 ± 0.2 s and V: 1.9 ± 0.3 s vs 3.8 ± 0.2 s; P < 0.001 for both) in older subjects, when compared to young. A matrix of bolus flow and presence above the EGJ indicated reductions in bolus flow at the EGJ occurred due to both impaired bolus transport through the esophageal body (i.e., the bolus never reached the EGJ) and increased flow resistance at the EGJ (i.e., the bolus retained just above the EGJ). CONCLUSION Bolus flow through the EGJ is reduced in asymptomatic older individuals. Both ineffective esophageal bolus transport and increased EGJ resistance contribute to impaired bolus flow

Inter- and intra-rater reliability of the Chicago Classification in pe-diatric high-resolution esophageal manometry recordings

This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving'.Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.Background The Chicago Classification (CC) facilitates interpretation of high-resolution manometry (HRM) recordings. Application of this adult based algorithm to the pediatric population is unknown. We therefore assessed intra and interrater reliability of software-based CC diagnosis in a pediatric cohort. Methods Thirty pediatric solid state HRM recordings (13M; mean age 12.1 ± 5.1 years) assessing 10 liquid swallows per patient were analyzed twice by 11 raters (six experts, five non-experts). Software-placed anatomical landmarks required manual adjustment or removal. Integrated relaxation pressure (IRP4s), distal contractile integral (DCI), contractile front velocity (CFV), distal latency (DL) and break size (BS), and an overall CC diagnosis were software-generated. In addition, raters provided their subjective CC diagnosis. Reliability was calculated with Cohen's and Fleiss’ kappa (κ) and intraclass correlation coefficient (ICC). Key Results Intra- and interrater reliability of software-generated CC diagnosis after manual adjustment of landmarks was substantial (mean κ = 0.69 and 0.77 respectively) and moderate-substantial for subjective CC diagnosis (mean κ = 0.70 and 0.58 respectively). Reliability of both software-generated and subjective diagnosis of normal motility was high (κ = 0.81 and κ = 0.79). Intra- and interrater reliability were excellent for IRP4s, DCI, and BS. Experts had higher interrater reliability than non-experts for DL (ICC = 0.65 vs ICC = 0.36 respectively) and the software-generated diagnosis diffuse esophageal spasm (DES, κ = 0.64 vs κ = 0.30). Among experts, the reliability for the subjective diagnosis of achalasia and esophageal gastric junction outflow obstruction was moderate-substantial (κ = 0.45–0.82). Conclusions & Inferences Inter- and intrarater reliability of software-based CC diagnosis of pediatric HRM recordings was high overall. However, experience was a factor influencing the diagnosis of some motility disorders, particularly DES and achalasia