Baseline Impedance Research Articles

Application of Lyon Consensus criteria for GORD diagnosis: evaluation of conventional and new impedance-pH parameters

ObjectiveTo validate Lyon Consensus criteria for diagnosing gastro-oesophageal reflux disease (GORD) by reflux monitoring.DesignManual review of impedance-pH tracings from patients with proton pump inhibitor (PPI)-dependent heartburn, evaluated off PPI. Acid...

B-PO03-133 BIPOLAR RADIOFREQUENCY ABLATION USING ANGIOPLASTY GUIDEWIRES

Intramural ventricular arrhythmias represent a challenge for catheter ablation. Angioplasty guidewires can be used to map septal coronary veins that are inaccessible to standard ablation catheters and eventually could have a role in the ablation of septal arrhythmogenic substrate. To evaluate the feasibility of bipolar radiofrequency (RF) ablation using an angioplasty guidewire as the return electrode. An ex-vivo model consisting of a piece of porcine myocardium submersed in a normal saline bath was used. RF energy was applied between an irrigated ablation catheter (Tacticath, Abbott) positioned on the endocardial surface and a partially coated angioplasty guidewire (Luge, Boston Scientific) placed on the adjacent epicardial surface, connected to the indifferent port of the RF generator. RF applications using powers between 20-50W resulted in effective lesion formation on both sides of the ventricular myocardium, but powers ≥30W were associated with a higher incidence of steam pops. When a power of 20W was applied (25 lesions) the baseline impedance was 180±22 Ω, with impedance drop of 44±17 Ω and no steam pops. The lesion volume was 237±182 mm3 and transmural lesions were observed in tissues measuring 10-15 mm thickness (Figure: In the left panel the orientation of the electrodes is oblique, resulting in 2 separate lesions; in the right panel both electrodes are directly opposed, resulting in a transmural lesion core). Bipolar RF ablation between an ablation catheter and an angioplasty guidewire is feasible and may result in transmural lesions. Further studies are required to confirm the efficacy and safety of this ablation approach.

B-PO03-034 INTRACARDIAC ECHOCARDIOGRAPHY VALIDATION OF SALINE-ENHANCED RADIOFREQUENCY NEEDLE-TIP ABLATION FOR THE CONTROLLABLE CREATION OF TRANSMURAL LESIONS

In saline-enhanced radiofrequency needle-tip (SERF) ablation, heated saline is injected into the myocardium via a needle, while the needle is used as a monopolar ablation electrode. In comparison to lesions created by conventional radiofrequency ablation, lesions created by SERF ablation are larger and more often transmural. With the implementation of SERF ablation, real-time validation of lesion formation is needed for the controllable creation of transmural lesions. The aim of the study was to analyze the ability of 2D-intracardiac echocardiography (ICE) and impedance measurements to detect transmural lesions. Fifty-six SERF energy deliveries at left ventricular sites of 11 dogs guided by 2D-ICE were analyzed (power: 15-50 W; time: 25-120 sec; irrigation saline: 60 °C with 10 mL/min flow rate). Impedance measurements were taken before, during, and after the energy delivery. One week after the ablation procedure, hearts were explanted en bloc for ex-vivo lesion validation. Continuous lesions from the endocardium to the epicardium were defined as transmural lesions. On 2D-ICE, 31 (63.3%) lesions were considered to be transmural. For 23 of these lesions, transmurality was confirmed in gross pathology, resulting in a sensitivity of 70%, a specificity of 47%, a positive predictive value of 74% and a negative predictive value of 59% for detecting transmural lesions. In confirmed transmural lesions, impedance measurements did not differ compared to non-transmural lesions on gross pathology (baseline impedance 85.5 Ω [IQR 79.5 - 95.8] vs. 84.0 Ω [IQR 82.0 - 85.0], p=0.497; impedance after SERF ablation 75.0 Ω [IQR 68.2 - 85.8] vs. 69.0 Ω [IQR 68.0 - 77.0], p=0.297; impedance drop 11.0 Ω [IQR 4.8 - 16.8] vs. 14.0 Ω [IQR 11.0 - 17.0], p=0.289 and impedance drop rate 13.5 % [IQR 5.9 - 16.6] vs. 17.1 % [IQR 13.8 - 19.4], p=0.183). 2D-ICE can potentially be used to guide and validate SERF ablation lesion formation in real-time for the controllable creation of transmural lesions.

The Results From Up-Front Esophageal Testing Predict Proton Pump Inhibitor Response in Patients With Chronic Cough.

The clinical management of chronic cough patients is challenging, and their response to proton pump inhibitors (PPIs) is considered as unsatisfactory. Few data concerning the association between impedance-pH variables and PPI response in these patients are available. Mean nocturnal baseline impedance (MNBI) and postreflux swallow-induced peristaltic wave (PSPW) index increase the diagnostic yield of impedance-pH in gastroesophageal reflux disease. Demographic, clinical, and endoscopy findings; impedance-pH; and high-resolution manometry tracings from consecutive patients assessed for cough were evaluated. Univariable and multivariable regression models were generated to evaluate the association between impedance-pH and high-resolution manometry findings, endoscopic and clinical characteristics, and PPI response. A total of 178 patients were included. Eighty-four of 178 cough patients (47.2%) displayed grade C-D erosive esophagitis or were characterized by a pathological acid exposure time (AET) and/or positive symptom association probability/symptom index. When also considering MNBI and PSPW, 135 of 178 patients (75.8%) were characterized by the evidence of reflux disease (P < 0.001). Eighty patients (44.9%) had cough responding to PPIs, whereas 98 (55.1%) were nonresponders (P = 0.071). At the receiver operating characteristic analysis, both PSPW index and MNBI were associated to PPI responsiveness. MNBI and PSPW index showed higher sensitivity in predicting PPI response compared with AET and symptom association probability/symptom index. The area under the curves of MNBI and PSPW index were significantly higher than that of AET (P < 0.01 for both comparisons). When patients were stratified according to AET and excluding those with erosive esophagitis, pathological MNBI or PSPW index, hiatal hernia, and hypomotility features were associated to PPI response in all groups. Our results demonstrate the usefulness of an up-front esophageal testing in discriminating reflux-related cough patients and predicting PPI response.

Derivation and Verification of the Relationship between Ablation Index and Baseline Impedance.

Objective To explore the quantitative adjustment of ablation index (AI) under different baseline impedance to achieve similar lesion dimensions. Methods (1) Keeping the AIs relatively constant, the lesion dimensions in different baseline impedances were studied. (2) According to Joule's law, Q = I2RT, keeping the current (I) unchanged, the powers corresponding to different baseline impedances can be obtained. Under different baseline impedances and corresponding powers, the swine hearts were ablated for 30 s in simulated human circumstances. The baseline impedances, the lesion dimensions, and AIs were recorded. And the derivation of empirical formula was achieved according to the AIs and baseline impedance values in similar lesions dimension. (3) Basic AI and baseline impedance (AI0/R0) were set as 400/120 Ω in the common AI groups and 550/120 Ω in the high AI groups, AI values in different baseline impedances were calculated using the empirical formula, and the corresponding lesion dimensions were measured to verify this formula. Results (1) Higher baseline impedances were related to smaller lesion dimensions at similar AIs. (2) The lesion dimensions were roughly the same after modulating the baseline impedance and power to keep the electric current relatively constant. The relationship between AI and R fitted with experimental data is AI = 1.9933R + 203.61 (r = 0.9649), and the formula derived is ΔAI = (AI0 − 203)/R0 × ΔR. (3) Under the guidance of the empirical formula, there was no significant difference in lesion dimensions between the standard group and the formula guiding groups when AI0 = 400, but there was a shrinking tendence when AI > 700. Conclusion The lesion depths are negatively correlated with baseline impedance at a certain AI. The relationship between baseline impedance and AI is “ΔAI = (AI0 − 203)/R0 × ΔR”. It is verified that when the AI is not too high, the empirical formula can be used to guide the quantitative adjustment of AIs at different baseline impedance, and the lesion depths achieved are roughly the same.

Novel impedance-pH parameters are associated with proton pump inhibitor response in patients with inconclusive diagnosis of gastro-oesophageal reflux disease according to Lyon Consensus.

SummaryBackgroundThe Lyon Consensus delineates impedance‐pH parameters that can demonstrate/exclude gastro‐oesophageal reflux disease (GERD). In patients with acid exposure time between 4% and 6%, GERD diagnosis has been considered inconclusive. In these cases, mean nocturnal baseline impedance (MNBI) and post‐reflux swallow‐induced peristaltic wave (PSPW) index may either confirm or refute GERD diagnosis and represent predictors of proton pump inhibitor (PPI) response.AimsTo investigate the diagnostic yield of MNBI and PSPW index and their relationship with PPI response in patients with inconclusive GERD diagnosis.MethodsReview of impedance‐pH tracings from PPI responder/non‐responder patients with typical reflux symptoms. Multivariate regression analysis was performed to determine the association of MNBI and PSPW index to PPI response.ResultsAmong 233 patients evaluated, 145/233 (62.2%) were PPI responders; 62 had conclusive and 65 inconclusive evidence of GERD, 46 had reflux hypersensitivity, and 60 functional heartburn. Abnormal MNBI and PSPW index were significantly more frequent in inconclusive GERD as compared to the functional heartburn group (P < 0.001). Within the inconclusive GERD group, 35/65 (54%) patients were PPI responders and displayed a significantly higher proportion of cases with pathological MNBI or PSPW index as compared to non‐responders (32/35 [91.4%] and 30/35 [85.7%] vs 9/30 [30%] and 7/30 [23.3%], P < 0.001). By multivariate analysis, pathological PSPW index and/or MNBI values were significantly associated with PPI response in all groups.ConclusionsThe present study highlights the value of MNBI and PSPW index as adjunctive metrics in characterising patients with inconclusive evidence of GERD and identifying those responsive to PPI treatment.

Conventional and simple methods of measuring esophageal nocturnal baseline impedance show excellent agreement.

Mean nocturnal baseline impedance (MNBI) shows promise in investigating reflux disease by reflecting esophageal mucosal integrity. This study aimed to measure MNBI by both conventional and simple methods in patients with laryngopharyngeal reflux (LPR) and gastroesophageal reflux disease (GERD) in order to evaluate the efficacy of the simple measurement method. Altogether 187 patients were divided into LPR (n=105) or GERD (n=82) groups according to their predominant symptom profile, and underwent off-therapy impedance-pH monitoring. MNBI was measured by both the conventional and simple methods. The Bland-Altman plots were constructed to assess mean differences and to identify bias in the two measurement methods. For the two measurement methods, mean difference was (-89 ± 328) Ω in the distal esophagus, (-6 ± 653) Ω in the proximal esophagus, and (128 ± 577) Ω in the pharynx, respectively. There was a strong correlation between conventional and simple MNBI values, with the coefficient of 0.940 in the distal esophagus, 0.463 in the proximal esophagus, and 0.712 in the pharynx (all P < 0.001). There was an excellent agreement between the conventional and simple methods of MNBI measurement, with no evidence of proportional bias. Conventional and simple MNBI values correlated excellently in the distal esophagus and moderately well in the proximal esophagus and pharynx. This study supports the use of the simple method of measuring MNBI to enhance diagnoses of reflux disease.

The Value of Reflux Monitoring: The Old and the New for the Diagnosis and Assessment of GERD

Reflux monitoring has advanced from inpatient continuous pH recordings on scrolling graph paper introduced 50 years ago to modern catheter-based 24-hour and wireless multiple-day ambulatory recordings, and the capability of detecting reflux episodes irrespective of pH using impedance technology. Testing is performed off antisecretory therapy when there is no prior documentation of reflux disease, and pH-impedance monitoring can be performed on therapy in symptomatic patients with proven reflux. Prolonged wireless pH monitoring evaluates day-to-day variation in reflux exposure. New impedance-based metrics evaluating baseline impedance and post-reflux swallow induced peristaltic wave have potential to augment the diagnostic value of reflux monitoring.

Esophageal luminal temperature rise during atrial fibrillation ablation is associated with lower radiofrequency electrode distance and baseline impedance

Esophageal injury during atrial fibrillation (AF) ablation is a life-threatening complication. We sought to measure the association of esophageal temperature attenuation with radiofrequency (RF) electrode impedance, contact force, and distance from the esophagus. The retrospective study cohort included 35 patients with mean age 64 ± 10 years, of whom 74.3% were male, and 40% had persistent AF. All patients had undergone preprocedural cardiac magnetic resonance (CMR) followed by AF ablation with luminal esophageal temperature monitoring. Lesion locations were co-registered with CMR image segmentations of left atrial and esophageal anatomy. Luminal esophageal temperature, time matched RF lesion data, and ablation distance from the nearest esophageal location were collected as panel data. Luminal esophageal temperature changes corresponding to 3667 distinct lesions, delivered with mean power 27.9 ± 5.5 W over a mean duration of 22.2 ± 10.5 s were analyzed. In multivariable analyses, clustered per patient, examining posterior wall lesions only, and adjusted for lesion power and duration as set by the operator, lesion distance from the esophagus (-0.003°C/mm, p < .001), and baseline impedance (-0.015°C/Ω, p < .001) were associated with changes in luminal esophageal temperature. Esophageal luminal temperature rises are associated with shorter lesion distance from esophagus and lower baseline impedance during RF lesion delivery. When procedural strategy requires RF delivery near the esophagus, selection of sites with higher baseline impedance may improve safety.

Sex-Based Differences in pH Parameters and Esophageal Impedance of Patients With Gastroesophageal Reflux Disease.

Background/Aims: The incidence of reflux esophagitis (RE) has a striking predominance in males. Conversely, non-erosive reflux disease (NERD) is more common in females. This imbalance of gastroesophageal reflux disease (GERD) implies sex-related differences in its pathogenesis. However, limited studies have analyzed the sex-based differences in pH parameters and esophageal impedance of GERD patients.Methods: This study evaluated sex-based pathogenesis differences by comparing reflux episodes, mean nocturnal baseline impedance (MNBI) values, and post-reflux swallow-induced peristaltic wave (PSPW) index values of males with GERD and females with GERD using 24-h multichannel intraluminal impedance and pH monitoring.Results: We analyzed 181 patients (102 males and 79 females) with GERD. Reflux symptom index (RSI) scores were higher in females than that in males (P < 0.05). Males had significantly longer acid exposure times, higher DeMeester scores, and more acid reflux episodes than females (P < 0.05). Females had more instances of weakly acidic reflux than males (P < 0.01). The PSPW index values of males and females were similar (P > 0.05). Compared with females, males had lower MNBI values for the mid and distal esophagus (P < 0.05). However, with increasing age, the MNBI values of females decreased more rapidly than those of males. MNBI values of elderly patients of both sexes older than 60 years were similar.Conclusions: Acid reflux is more likely to occur in males; however, females tend to have more instances of weakly acid reflux. The integrity of the esophageal mucosa is more fragile in males than in females; however, the esophageal mucosal barrier attenuates more rapidly with increasing age in females than in males.

Percutaneous radiofrequency ablation for hepatic tumors: factors affecting baseline impedance.

We aimed to evaluate factors that affect baseline impedance of percutaneous radiofrequency ablation. In this retrospective study, we analyzed 51 patients with 55 hepatic tumors from November 2015 until April 2018. We measured the baseline impedance nine times with three adjustable tip sizes (2 cm, 2.5 cm, 3 cm) and three different pad locations (two pads attached on the thigh, four on the thigh, two on the back). The first roll-off time was measured with two grounding pads attached on the back. Body mass index, cirrhotic or non-cirrhotic liver parenchyma, previous procedure, tumor location, artificial ascites, active tip size, and the pad location were evaluated as potential factors affecting baseline impedance using the Mann-Whitney U test, t-test and analysis of variance test. Complete radiofrequency ablation was achieved in 51 patients. Body mass index (p = 0.897), cirrhotic or non-cirrhotic liver parenchyma (p = 0.767), previous procedure (p = 0.957), tumor location (p = 0.906), and artificial ascites (p = 0.882) did not significantly affect baseline impedance. Grounding pads located on the back showed the lowest baseline impedance (p < 0.001). Increase in active tip size showed gradual decrease in baseline impedance (p = 0.016). The factors affecting baseline impedance were the pad location and the tip size. Positioning pads on the back lowers the baseline impedance and can shorten the first roll-off time, ultimately resulting in reduced total ablation time.

Simultaneous Evaluation of Laryngopharyngeal Reflux and Swallowing Function Using Hypopharyngeal Multichannel Intraluminal Impedance Measurements in Neurologically Impaired Patients.

Background/AimsThis study aims to evaluate the presence of laryngopharyngeal reflux (LPR) and to investigate the use of hypopharyngeal baseline impedance (BI) for assessing swallowing dysfunction and gastroesophageal reflux disease (GERD) using hypopharyngeal multichannel intraluminal impedance and pH (HMII-pH) monitoring in neurologically impaired patients (NIPs).MethodsThe study population in this retrospective study comprised 20 NIPs (mean age, 36.1 ± 15.0 years; age range, 13-64 years) who underwent multichannel intraluminal impedance and pH (MII-pH), HMII-pH, and laryngoscopy using the Hyodo scoring method from December 2016 to April 2019. The MII-pH and HMM-pH parameters were compared in the NIPs, whereas hypopharyngeal BI values were compared between NIPs with ≥ 5 and < 5 in Hyodo scores. Correlations between the hypopharyngeal BI values and the Hyodo score were analyzed using Spearman’s correlation coefficient. A receiver operator characteristic curve was created to determine the optimum cut-off of hypopharyngeal BI value to discriminate SD.ResultsThree NIPs were diagnosed with pathological LPR and GERD by the HMII-pH monitoring. No significant differences in parameters were observed between MII-pH and HMII-pH monitoring. The correlation analysis demonstrated a significant negative correlation between the hypopharyngeal BI values and Hyodo scores. The optimal cutoff value for hypopharyngeal BI was 1552 Ω.ConclusionsThis study demonstrated the usefulness of HMII-pH monitoring in identifying NIP with pathological LPR. Considering the difficulties in performing examinations in NIPs, HMII-pH monitoring may be a potentially useful technique for the simultaneous evaluation of swallowing dysfunction, LPR, and GERD in NIP.

Micropore Closure Rates following Microneedle Application at Various Anatomical Sites in Healthy Human Subjects

Introduction: The continuous availability of open micropores is crucial for a successful microneedle (MN) drug delivery strategy. However, micropore lifetime depends on intrinsic skin functional and anatomical characteristics, which vary significantly at different anatomical sites. Objective: This pilot study explored if differences exist in micropore closure timeframes at 3 anatomical sites – upper arm, volar forearm, and abdomen. Methods: Healthy subjects (n = 35) self-identifying as Asian (n = 9), Bi-/multiracial (n = 2), Black (n = 9), Latino (n = 6), and White (n = 9) completed the study. The upper arm, volar forearm, and abdomen were treated with MNs; skin impedance and transepidermal water loss (TEWL) were measured at baseline and post-MN to confirm micropore formation. Impedance was measured for 3 days to evaluate micropore lifetime. Measurements of L*, which quantifies the skin lightness/darkness, were made using a tristimulus colorimeter. Micropore lifetime was determined by comparing baseline and post-MN impedance measurements, and micropore closure half-life was predicted using mathematical modeling. Results: Post-MN increase in TEWL and decrease in impedance were significant (p < 0.05), confirming successful micropore formation at all anatomical sites. When data were analyzed according to subject self-identified racial/ethnic groups, the mean micropore closure time at the abdomen (63.09 ± 13.13 h) was longer than the upper arm (60.34 ± 14.69 h) and volar forearm (58.29 ± 16.76 h). The predicted micropore closure half-life at anatomical sites was the abdomen (25.86 ± 14.96 h) ≈ upper arm (23.69 ± 13.67 h) > volar forearm (20.2 ± 11.99 h). Differences were not statistically significant between groups. Objective categorization by L* showed that the darker skin may be associated with longer micropore closure time at the abdomen site. Conclusions: Our results suggest that anatomical site of application may not be a source of significant variability in micropore closure time. These findings may help reduce the number of physiological parameters that need to be explicitly considered when developing drug products to support MN-assisted drug delivery strategies.

Response of eosinophilic oesophagitis to proton pump inhibitors is associated with impedance‐pH parameters implying anti‐reflux mechanism of action

SummaryBackgroundProton pump inhibitors (PPIs) are effective therapies for eosinophilic oesophagitis (EoE), but the mechanism of action is uncertain. At on‐PPI impedance‐pH monitoring, improvement in oesophageal chemical clearance assessed with post‐reflux swallow‐induced peristaltic wave (PSPW) index characterises PPI‐responsive EoE and reflux disease. Off‐PPI, higher efficacy of the oesophago‐salivary reflex as measured with PSPW‐associated pH increments characterises PPI‐responsive reflux disease and could typify PPI‐responsive EoE as well.AimTo establish whether PPI responsiveness in EoE is associated with higher efficacy of the oesophago‐salivary reflex.MethodsProspective multicentre study in EoE patients investigated with impedance‐pH monitoring before starting PPI. Impedance‐pH parameters in PPI‐responsive and PPI‐refractory cases were compared. PPI response was defined histologically.ResultsConsiderable PSPW‐associated pH increments (median 1.4 units) were found in 80 EoE patients, with significantly higher values in 48 PPI‐responsive than in 32 PPI‐refractory cases (1.8 vs 1.0, P = 0.02). Mucosal integrity, as measured with mean nocturnal baseline impedance was more severely impaired in the distal oesophagus in PPI‐responsive cases, the gradient between mid and distal oesophagus being significantly higher (546 vs 137 Ω, P = 0.0002). PSPW‐associated pH increments and the baseline impedance gradient between mid and distal oesophagus were independently associated with histological response at multivariable logistic regression; at receiver operating characteristic analysis, the area under the curve of PPI response calculated by combined assessment was 0.88.ConclusionHigher efficacy of oesophago‐salivary reflex and more severe mucosal damage in the distal oesophagus are associated with EoE response to PPIs, implying an anti‐reflux mechanism of action as most likely.

Analysis of contractile segment impedance during straight leg raise maneuver using high-resolution impedance manometry increases diagnostic yield in reflux disease.

Contractile segment impedance (CSI) obtained from high-resolution impedance manometry (HRIM) is a measure of mucosal integrity that predicts gastroesophageal reflux disease (GERD). While straight leg raise (SLR) maneuver augments esophageal peristaltic vigor, it remains unclear whether SLR affects CSI values. This study was aimed to evaluate whether CSI with SLR is feasible and useful to complement the diagnosis of GERD. We prospectively recruited 48 patients with typical GERD symptoms who underwent esophagogastroduodenoscopy, HRIM with SLR maneuver, and multichannel intraluminal impedance-pH (MII-pH) testing. The capability of mean nocturnal baseline impedance (MNBI), resting baseline impedance (RBI), CSI with or without SLR maneuver in predicting GERD was assessed using receiver operating characteristics (ROC) analysis. Among 20 GERD patients and 28 non-GERD patients, all values of impedance-based metrics were lower in GERD patients compared to non-GERD patients (p<0.001). For GERD identification, area under receiver operating characteristic curve (AUROC) values of CSI with SLR maneuver, CSI, MNBI, and RBI were 0.901, 0.858, 0.865, and 0.797. Particularly in ineffective esophageal motility (IEM) patients, SLR maneuver increased mean distal contractile integral from 436 to 828.7mmHg.s.cm (p=0.018) and enhanced AUROC values of CSI for GERD identification from 0.917 to 0.958. CSI measurement during HRIM appears to be a reliable, time-saving, and less invasive tool for complementing GERD diagnosis. Our results also suggest a simple SLR maneuver during HRIM could enhance diagnostic accuracy of CSI for GERD identification especially in IEM patients.

Multichannel impedance monitoring for distinguishing nonerosive reflux esophagitis with minor changes on endoscopy in children.

Objectives:There are reports describing the relationship between baseline impedance level and esophageal mucosal integrity at endoscopy, such as erosive and nonerosive reflux esophagitis. However, many children with symptoms of gastroesophageal reflux disease have normal findings or minor changes on esophagogastroduodenoscopy. We aimed to examine whether modest changes at esophagogastroduodenoscopy can be evaluated and correlated with esophageal multichannel intraluminal impedance monitoring.Methods:Patients (ages 0–17 years) with upper gastrointestinal symptoms who underwent combined esophagogastroduodenoscopy and multichannel intraluminal impedance monitoring at the Women’s and Children’s Hospital, Adelaide, Australia, between 2014 and 2016 were retrospectively studied and the following data were collected and used for analysis: demographics, multichannel intraluminal impedance data, included baseline impedance. Endoscopic findings were classified by modified Los Angeles grading, Los Angeles N as normal, Los Angeles M as with minimal change such as the erythema, pale mucosa, or friability of the mucosa following biopsy. Patients on proton pump inhibitor were excluded.Results:Seventy patients (43 boys; 61%) were enrolled with a mean age of 7.9 years (range 10 months to 17 years). Fifty-one patients (72.9%) were allocated to Los Angeles N, while Los Angeles M was evident in 19 patients (27.1%). Statistically significant differences were observed in the following parameters: frequency of acid and nonacid reflux and baseline impedance in channels 5 and 6. The median values of the data were 18.3 episodes, 16.0 episodes, 2461.0 Ω, 2446.0 Ω in Los Angeles N, 36.0 episodes, 31.0 episodes, 2033.0 Ω, 2009.0 Ω in Los Angeles M, respectively.Conclusion:Lower baseline impedance is helpful in predicting minimal endoscopic changes in the lower esophagus. A higher frequency of acid and nonacid reflux episodes was also predictive of minimal endoscopic change in the lower esophagus.

Value of adjunctive evidence from MII-pH monitoring and high-resolution manometry in inconclusive GERD patients with AET 4-6.

Objectives:Gastro-esophageal reflux disease (GERD) is a common disease in gastroenterology outpatients. However, some patients with typical reflux symptoms does not satisfy diagnostic criteria. This study was to explore the value of adjunctive evidence from multichannel intraluminal impedance-pH (MII-pH) monitoring and esophageal high-resolution manometry (HRM) in inconclusive GERD patients with acid exposure time (AET) 4–6%.Methods:Endoscopy, MII-pH monitoring and esophageal HRM were retrospectively analyzed from consecutive patients with typical reflux symptoms in a tertiary hospital from 2013 to 2019. Patients were categorized as conclusive or inconclusive GERD according to AET. Adjunctive evidence for GERD diagnosis from Lyon Consensus were collected and analyzed.Results:Among 147 patients with typical reflux symptoms, conclusive GERD was found in only 31.97% of patients (N = 47). The remaining 100 patients (68.03%) were inconclusive GERD, of whom 28% (N = 28) had AET 4–6%. These patients suffered similar reflux burden and impaired esophageal movement. Inconclusive GERD patients with AET 4–6% had lots of positive adjunctive evidence from HRM and MII-pH monitoring. In receiver operating characteristic analysis, mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave index (PSPWI) had an area under the curve (AUC) of 0.839 (CI: 0.765–0.913, p < 0.001) and 0.897 (CI: 0.841–0.953, p < 0.001), respectively, better than total reflux episode (AUC of 0.55, p = 0.33). When MNBI was combined with PSPWI, the AUC was elevated to 0.910 (CI: 0.857–0.963, p < 0.001).Conclusions:Inconclusive GERD patients with AET 4–6% have similar acid burden and esophagus motility dysfunction to GERD patients. MNBI and PSPWI are pivotal adjunctive evidence for diagnosing GERD when AET is borderline.

Особенности течения и сравнительная характеристика гастроэзофагеальной рефлюксной болезни у пациентов детского возраста с атрезией пищевода после первичной пластики

The aim is to evaluate clinical data and data of intraesophageal 24-hour pH/impedance measurement in pediatric patients with corrected esophageal atresia. Material and methods. A retrospective analysis was carried out on the basis of inpatient records of 43 pediatric patients with corrected esophageal atresia (CEA) aged from 1 to 14 years, who were examined at the State Institution «Republican Scientific and Practical Center of Pediatric Surgery» from November 2017 to March 2020. Average age of the group: 5.09±1.2 years, of which 23 boys (53.5%), 20 girls (46.5%). All patients with CEA underwent esophagogastroduodenoscopy (EGD) and intraesophageal 24-hour pH/impedance measurement while off acid-suppressive therapy. Results. Depending on the results of pH/impedance measurement, the patients with CEA were divided into two groups: CEA with gastroesophageal reflux disease (GERD) – 20 (54.1%) and CEA without GERD – 17 (45.9%). The most common symptom in patients with CEA was cough in both groups, in 26 (70.27%) children. Only in 4 out of 37 patients with CEA no symptoms during the time of the study were registered. Upper gastrointestinal tract endoscopy showed that 16 (43.2%) children with CEA had grade A esophagitis (according to the Los Angeles classification), 1 (2.7%) had gastric metaplasia of the esophageal mucosa, and 6 (16.2%) had chronic gastritis. EGD data did not reveal any significant differences between CEA patients with GERD and CEA patients without GERD (P=0.819). When comparing pH/impedance parameters, a significant difference (P&lt;0.005) was obtained for the following parameters: reflux index, number of reflux episodes, distal mean nocturnal baseline impedance (MNBI) and duration of the longest reflux episode. In addition, the positive association of symptoms with episodes of refluxes (&gt;95%) in the group of CEA patients without GERD was significantly higher than in CEA patients with GERD: 3/20 (15%) versus 8/17 (47.06%). Conclusions. The prevalence of GERD in patients with CEA in this study was 54.06%. Extraesophageal symptoms (in particular, cough) are prevalent in patients with CEA (70.3%). GERD can be asymptomatic in patients with CEA. In this study, 15% of CEA patients with confirmed GERD were asymptomatic. Patients with CEA in the study groups rarely had typical GERD symptoms (heartburn, regurgitation, chest pain and belching). The research was carried out in accordance with the principles of the Declaration of Helsinki. The research protocol was approved by the Local Ethics Committee of the institutions indicated in the article. Informed consent of parents and children was obtained for the research. The authors declare no conflicts of interest. Key words: corrected esophageal atresia, gastroesophageal reflux disease, esophagitis, children, esophageal 24-hour pH/impedance measurement.

Overlap of functional heartburn and reflux hypersensitivity with proven gastroesophageal reflux disease

AbstractBackgroundWhen esophageal acid exposure time (AET) is physiologic, ROME IV stratifies functional esophageal disorders into functional heartburn (FH, with negative reflux‐symptom association) and reflux hypersensitivity (RH, with positive reflux‐symptom association), and hypothesizes that FH/RH could overlap with proven gastroesophageal reflux disease (GERD). We compared conventional FH/RH diagnosed off antisecretory therapy with overlap FH/RH coexisting with proven GERD.MethodsAdult patients with heartburn underwent pH‐impedance testing on therapy (proven GERD) and off therapy (unproven GERD) and completed validated questionnaires defining symptoms (Reflux Diagnostic Questionnaire, RDQ), affective state (Hospital Anxiety and Depression Scale, HADS; Visceral Sensitivity Index, VSI), and functional diagnoses (irritable bowel syndrome, IBS; functional dyspepsia, FD on ROME diagnostic questionnaire). AET (pathologic: &gt;6%, physiologic &lt;4%) and mean nocturnal baseline impedance (MNBI) were calculated. Clinical, psychological, and functional profiles were compared between FH and RH and to a comparison cohort of non‐erosive reflux disease (NERD, AET &gt; 6%).Key ResultsStudy patients included 19 with RH (10 with overlap RH), 60 with FH (31 with overlap FH), and 26 patients with NERD. Clinical, psychological, and functional profiles of conventional FH/RH were similar to overlap FH/RH. Compared with NERD, combined FH and RH cohorts had higher anxiety scores, and lower proportions with IBS. Compared with FH with low MNBI, FH defined using both normal AET and normal MNBI had higher depression scores (p = 0.008), and trended toward higher anxiety scores (p = 0.059).Conclusions and InferencesConventional and overlap FH and RH have similar clinical, psychological and functional profiles, thereby proving ROME IV hypotheses.

The Role of Salivary Pepsin in the Diagnosis of Gastroesophageal Reflux Disease (GERD) Evaluated Using High-Resolution Manometry and 24-Hour Multichannel Intraluminal Impedance-pH Monitoring.

BackgroundThe Lyon Consensus classification confirms or rules out gastroesophageal reflux disease (GERD). The refractory symptoms of patients with GERD taking proton pump inhibitors (PPIs) are challenging in clinical practice. Salivary pepsin concentration was proposed as a diagnostic biomarker for GERD. We aimed to determine the diagnostic value of salivary pepsin concentration for patients with conclusive GERD, based on the Lyon classification, and the correlation of salivary pepsin concentration with parameters of high-resolution manometry and 24-h multichannel intraluminal impedance-pH in patients with PPI-refractory symptoms.Material/MethodsSaliva samples obtained from 130 patients who were suspicious for GERD and had PPI-refractory symptoms were used for pepsin determination using the enzyme-linked immunosorbent assay. All patients underwent upper gastrointestinal endoscopy, high-resolution manometry, 24-h multichannel intraluminal impedance, and pH recording and were classified as conclusive GERD, inconclusive GERD, and evidence against GERD groups according to Lyon classification.ResultsSalivary pepsin concentration was 8.2 ng/mL (3.8–17.8 ng/mL), 4.0 ng/mL (2.3–6.1 ng/mL), and 2.4 ng/mL (2.2–3.1 ng/mL) in conclusive GERD, inconclusive GERD, and evidence against GERD groups, respectively (P<0.001), and had a negative correlation with distal mean nocturnal baseline impedance and positive correlations with acid exposure time, total number of reflux events, and esophagogastric junction type. The area under the ROC curve of salivary pepsin for conclusive GERD was 0.76 (0.68–0.84), with a sensitivity of 76.36% and a specificity of 63.41% for conclusive GERD diagnosis at a cut-off value of 4.21 ng/mL.ConclusionsSalivary pepsin test had moderate diagnostic value for conclusive GERD by Lyon classification in patients with PPI-refractory symptoms.