Measurement of mucosal conductivity by MII is a potential marker of mucosal integrity restored in infants on acid-suppression therapy

Esophageal impedance baseline in infants with bronchopulmonary dysplasia: A pilot study

BACKGROUND

Bronchopulmonary dysplasia (BPD) may induce gastroesophageal reflux (GER). Esophageal impedance baseline values (BI) reflect mucosal inflammation. Our aim was to evaluate BI levels in preterm infants with BPD compared with those without BPD and to identify BI predictors.

METHODS

This is a retrospective pilot study including infants born <32 weeks' gestational age (GA) who underwent esophageal multichannel intraluminal impedance (MII)-pH. Univariate/multivariate analysis were performed to compare data between BPD and non-BPD infants and to identify BI predictors. A subgroup analysis was performed in infants born <29 weeks' GA, at highest risk for BPD.

RESULTS

Ninety-seven patients (median GA 28^5/7 weeks, mean postnatal age 49 days, 29 with BPD), were studied. BPD infants had significantly lower birth weight compared with non-BPD infants (750 vs. 1275 g), were more immature (27^4/7 vs. 29^0/7 weeks GA), were older at MII-pH (79 vs. 38 days) and received less fluids during MII-pH (147 vs. 161 ml/kg/day). The same findings were found in the group of 53 infants born <29 weeks. BPD versus non-BPD infants had significantly lower BI (2050 vs. 2574 ohm, p = 0.007) (<1000 ohm in five BPD infants vs. one non-BPD) whereas the other MII-pH parameters were not significantly different. Multiple regression analysis found that increasing chronological age was positively associated with BI (B = 9.3, p = 0.013) whereas BPD was associated with lower BI (B = -793.4, p < 0.001).

CONCLUSIONS

BPD versus non-BPD infants had significantly lower BI despite similar MII-pH data. BPD and chronological age predicted BI, whereas only BPD predicted BI in the most immature infants.

Response to therapy among neonates with gastro-esophageal reflux is associated with esophageal clearance

BACKGROUND

Few studies evaluated the efficacy of pharmacological therapy for gastro-esophageal reflux disease (GERD) in newborns, whose safety has been questioned. Esophageal basal impedance (BI) is a marker of mucosal integrity, and treatment with proton pump inhibitors significantly increases BI in infants; however, no correlation with clinical improvement was reported.

AIMS

To evaluate the relationship between BI and other esophageal pH-impedance parameters and clinical response to therapy in newborns with GERD.

STUDY DESIGN

Multicenter retrospective study.

SUBJECTS

Infants who received omeprazole or ranitidine for GERD.

OUTCOME MEASURES

Complete response to therapy was defined as symptom decrease by ≥50% compared to baseline, partial response as symptom decrease <50%, no response as no symptom decrease based on chart analysis. Response to therapy was assessed 2 and 4 weeks after the onset of therapy. Univariate and multivariate statistics were performed to assess associations between response to therapy and clinical/pH-impedance parameters.

RESULTS

We studied 60 infants (51 born preterm): 47 received omeprazole, 13 ranitidine. Response to therapy was associated with decreasing esophageal clearance time: odds ratio 0.308, 95%CI 0.126-0.753, p = 0.010 at 2 weeks, odds ratio 0.461, 95%CI 0.223-0.955, p = 0.037 at 4 weeks.

CONCLUSIONS

Clinical response to therapy among infants with GERD was associated with esophageal clearance but not with esophageal BI level.

Esophageal pH-impedance monitoring in children: position paper on indications, methodology and interpretation by the SIGENP working group

Multichannel intraluminal impedance pH (MII-pH) monitoring currently represents the gold standard diagnostic technique for the detection of gastro-esophageal reflux (GER), since it allows to quantify and characterize all reflux events and their possible relation with symptoms. Over the last ten years, thanks to its strengths and along with the publication of several clinical studies, its worldwide use has gradually increased, particularly in infants and children. Nevertheless, factors such as the limited pediatric reference values and limited therapeutic options still weaken its current clinical impact. Through an up-to-date review of the available scientific evidence, our aim was to produce a position paper on behalf of the working group on neurogastroenterology and acid-related disorders of the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP) on MII-pH monitoring technique, indications and interpretation in pediatric age, in order to standardise its use and to help clinicians in the diagnostic approach to children with GER symptoms.

Optimizing the Use of Medications and Other Therapies in Infant Gastroesophageal Reflux

Gastroesophageal reflux (GER) is the retrograde movement of gastric (and sometimes duodenal) contents into the esophagus. While the majority of GER is physiologic, for patients, it can be associated with symptoms. While some symptoms are merely bothersome (crying), others can be life threatening (cough, gagging, choking). The main driver of GER in infants is the frequent feedings that produce increased intra-abdominal pressure, which is known to trigger transient relaxations of the lower esophageal sphincter. The recent 2018 clinical practice guidelines reported by the North American and European Societies for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN/ESPGHAN) have recommended non-pharmacologic management initially with subsequent consideration of brief trials with acid suppressants. The main target for these acid suppressants is the gastric parietal cells. Our review of the literature has revealed a paucity of data regarding the use of histamine-2 receptor antagonists and proton pump inhibitors in infants. Despite the absence of well-controlled clinical studies, the prescription rate of these medications has increased internationally. Risks to patients of all ages have become increasingly recognized, with new associations being reported all too often. Here we report our review of all pharmacologic modalities as well as some non-surgical options.

Low-impedance Baseline Values Predict Severe Esophagitis

OBJECTIVES

The aim of the study was to determine whether esophageal baseline impedance (BI) values in children could be predictive of esophagitis.

MATERIALS AND METHODS

Multichannel intraluminal impedance (MII) tracings of children 3 to 17 years of age suspected of having gastroesophageal reflux and esophagitis, who had also undergone upper endoscopy with multiple esophageal biopsies, were reviewed. Patients with eosinophilic esophagitis were excluded. Esophagitis was assessed by macroscopic and microscopic parameters. Esophageal histology was reported by 2 blinded independent pathologists unaware of the MII results. Mean BI was automatically calculated in the different MII channels (ch) by the specific software without removing any episode of increased/decreased BI. BI results were plotted against macroscopic and histological scores for each channel.

RESULTS

Tracings of 87 children, 53 boys, were evaluated. Mean age was 7.4 years: 45 had histologic esophagitis, 8 macroscopic. Histologic mild esophagitis (grade 1) was observed in 30, and 15 had moderate to severe esophagitis (grade 2-3). Ten had grade 3 esophagitis. Eight had macroscopic esophagitis as well.

RESULTS

in channel 6 of the MII, all 10 patients with grade 3 esophagitis and the 8 with macroscopic esophagitis had a BI <900 Ω/s (positive predictive value 100% and negative predictive value 100%), whereas none of those having a biopsy score of 0 to 2 or no endoscopic evidence of esophagitis had a mean BI below 2000 Ω/s.

CONCLUSIONS

The evaluation of the BI measured in channel 6 gave us 100% prediction of grade 3 and macroscopic esophagitis. BI on channel 6 may be useful to predict severe esophageal mucosa inflammation and could potentially be used for follow-up evaluation, rather than repeating an upper endoscopy. In addition, it would seem that grade 3 esophagitis even in the absence of macroscopic esophagitis affects the integrity of the esophageal epithelium.

Advances with Neonatal Aerodigestive Science in the Pursuit of Safe Swallowing in Infants: Invited Review

Feeding, swallowing, and airway protection are three distinct entities. Feeding involves a process of sequential, neurosensory, and neuromotor interactions of reflexes and behaviors facilitating ingestion. Swallowing involves anterograde bolus movement during oral-, pharyngeal-, and esophageal phases of peristalsis into stomach. During these events, coordination with airway protection is vital for homeostasis in clearing any material away from airway vicinity. Neurological-airway-digestive inter-relationships are critical to the continuum of successful feeding patterns during infancy, either in health or disease. Neonatal feeding difficulties encompass a heterogeneous group of neurological, pulmonary, and aerodigestive disorders that present with multiple signs posing as clinical conundrums. Significant research breakthroughs permitted understanding of vagal neural pathways and functional aerodigestive connectivity involved in regulating swallowing and aerodigestive functions either directly or indirectly by influencing the supra-nuclear regulatory centers and peripheral effector organs. These neurosensory and neuromotor pathways are influenced by pathologies during perinatal events, prematurity, inflammatory states, and coexisting medical and surgical conditions. Approaches to clarify pathophysiologic mapping of aerodigestive interactions, as well as translating these discoveries into the development of personalized and simplified feeding strategies to advance child health are discussed in this review article.

Laparoscopic Nissen fundoplication mainly reduces the volume of acid reflux and potentially improves mucosal integrity up to the middle esophagus in neurologically impaired children detected by esophageal combined pH-multichannel intraluminal impedance measurements

BACKGROUND

The aim of this study was to evaluate detailed changes of gastroesophageal reflux disease (GERD) in children before and after laparoscopic Nissen fundoplication (LNF) utilizing esophageal combined pH-multichannel intraluminal impedance (pH/MII) measurements.

PATIENTS AND METHODS

Thirteen patients with neurological impairment, who received laparoscopic Nissen fundoplication (LNF) owing to refractory pathological GERD, were enrolled in this study. 24h pH/MII was conducted in all patients before and one year after LNF. Each parameter of the pH/MII was evaluated and compared each other.

RESULTS

Both the mean pH index and bolus exposure index after LNF were significantly lower than those before LNF. The mean numbers of total and nonacid reflux episodes after LNF were significantly lower than those before LNF. The mean numbers of total, acid and nonacid proximal reflux episodes after LNF were significantly lower than those before LNF. The mean baseline impedance values from Z3 to Z6 after LNF were significantly higher than those before LNF.

CONCLUSIONS

The present study provides new insights into the effects of LNF in pediatric patients, which prevents mainly acid reflux episodes from rising to the proximal esophagus, and is expected to improve the mucosal integrity up to the middle esophagus.

Biomarkers of Reflux Disease

Gastroesophageal reflux disease (GERD) encompasses an array of disorders unified by the reflux of gastric contents. Because there are many potential disease manifestations, esophageal and extraesophageal, there is no single biomarker of the entire disease spectrum; a set of GERD biomarkers that each quantifies specific aspects of GERD-related pathology might be needed. We review recent reports of biomarkers of GERD, specifically in relation to endoscopically negative esophageal disease and excluding conventional pH-impedance monitoring. We consider histopathologic biomarkers, baseline impedance, and serologic assays to determine that most markers are based on manifestations of impaired esophageal mucosal integrity, which is based on increased ionic and molecular permeability, and/or destruction of tight junctions. Impaired mucosal integrity quantified by baseline mucosal impedance, proteolytic fragments of junctional proteins, or histopathologic features has emerged as a promising GERD biomarker.

Low mean impedance in 24-hour tracings and esophagitis in children: a strong connection

Esophageal multiple intraluminal impedance baseline is an additional impedance parameter that was recently related to esophageal integrity. The aim of this study was to assess the relationship between mean esophageal impedance value and endoscopic findings in a large group of children. Children with symptoms of gastroesophageal reflux submitted to both endoscopy and impedance were included. Esophagitis was graded according to the Los Angeles classification. Mean impedance value was automatically calculated over 24-hour tracings. Data were adjusted for age through z-score transformation using percentiles normalized by the LMS (Lambda for the skew, Mu for the median, and Sigma for the generalized coefficient of variation) method. Nonparametric Mann-Whitney and Kruskal-Wallis tests, multiple, and stepwise regression were used. P-value <0.05 was considered as statistically significant. A total of 298 impedance tracings were analyzed. Endoscopic and histological esophagitis were detected in 30 and 29% patients, respectively. Median baseline z-score was significantly decreased both in proximal (P = 0.02) and distal (P = 0.01) esophagus in patients with endoscopic (but not histological) esophagitis. Patients with more severe esophagitis showed the lowest z-score. Bolus exposure index and the number of reflux episodes were the variables that were significantly associated with the baseline z-score. Impedance z-score is significantly decreased in infants and children with endoscopic esophagitis. Severity of esophagitis, bolus exposure index, and number of reflux episodes are factors influencing mean esophageal impedance.

Mucosal impedance discriminates GERD from non-GERD conditions

BACKGROUND & AIMS

Current diagnostic tests for gastroesophageal reflux disease (GERD) are suboptimal and do not accurately and reliably measure chronicity of reflux. A minimally invasive device has been developed to assess esophageal mucosal impedance (MI) as a marker of chronic reflux. We performed a prospective longitudinal study to investigate MI patterns in patients with GERD and common nonreflux conditions, to assess MI patterns before and after treatment with proton pump inhibitors and to compare the performance of MI and wireless pH tests.

METHODS

We evaluated MI in 61 patients with erosive esophagitis, 81 with nonerosive but pH-abnormal GERD, 93 without GERD, 18 with achalasia, and 15 with eosinophilic esophagitis. MI was measured at the site of esophagitis and at 2, 5, and 10 cm above the squamocolumnar junction in all participants. MI was measured before and after acid suppressive therapy, and findings were compared with those from wireless pH monitoring.

RESULTS

MI values were significantly lower in patients with GERD (erosive esophagitis or nonerosive but pH-abnormal GERD) or eosinophilic esophagitis than in patients without GERD or patients with achalasia (P < .001). The pattern of MI in patients with GERD differed from that in patients without GERD or patients with eosinophilic esophagitis; patients with GERD had low MI closer to the squamocolumnar junction, and values increased axially along the esophagus. These patterns normalized with acid suppressive therapy. MI patterns identified patients with esophagitis with higher levels of specificity (95%) and positive predictive values (96%) than wireless pH monitoring (64% and 40%, respectively).

CONCLUSIONS

Based on a prospective study using a prototype device, measurements of MI detect GERD with higher levels of specificity and positive predictive values than wireless pH monitoring. Clinical Trials.gov, Number: NCT01556919.

Behind the (impedance) baseline in children

Impedance baseline is a new parameter recently related to esophageal integrity. The aim of this study was to assess the effect of different factors on impedance baseline in pediatric patients. We analyzed the impedance baseline of 800 children with symptoms of gastroesophageal reflux. Mean impedance baseline was automatically calculated throughout 24-hour tracings. The presence of different age groups and of esophagitis was evaluated. Unpaired t-test, Spearman rank correlation, polynomial, and regression plot were used for statistical analysis. Age-related percentile curves were created. We considered a P-value<0.05 as statistically significant. Impedance baseline was significantly (P<0.001) lower in younger compared to older children up to 48 months. The mean increase of baseline per month was much higher in the first 36 months of life (47.5 vs. 2.9 Ohm in Channel 1 and 29.9 vs. 2.3 Ohm in Channel 6, respectively) than in older ages. Patients with esophagitis showed significantly decreased impedance baseline (P<0.05). Infants (especially in the first months of life) and young children present a significantly lower impedance baseline compared to older children both in proximal and distal esophagus. The presence of esophagitis may also determine a decreased impedance baseline regardless of the age of the patients.

Esophageal impedance baseline is age dependent

OBJECTIVE

Esophageal impedance (multichannel intraluminal impedance [MII]) baseline (impedance baseline [IB]) has been recently considered to be related to esophageal integrity. The aim of this study was to analyze the age effect on IB in a large population of pediatric patients.

DESIGN

A total of 816 children with symptoms of gastroesophageal reflux and submitted to MII were included. Mean IB was automatically calculated in the different MII channels (Chs) throughout 24-hour tracings by the specific software without removing any episode of increased/decreased IB. Acid and nonacid reflux parameters and age subgroups analysis were performed. Unpaired t test, Spearman rank correlation, polynomial and regression plot, multiple regression analysis, factorial analysis of variance, and the least mean squares method were used for statistical analysis and age-related percentile curves. P < 0.05 was considered as statistically significant.

RESULTS

Mean IB was significantly (P < 0.001) lower in younger compared with older children up to 48 months. The mean increase of IB per month was 2.9 Ω in Ch 1 and 2.3 Ω in Ch 6, but much higher in the first 36 months of life (47.5 Ω in Ch 1 and 29.9 Ω in Ch 6, respectively). From 48 months onward, there was no significant increase of the mean IB (P = 0.73). In the multiple regression analysis, only age and reflux index (but no other reflux parameters) significantly correlated with IB. Distal IB was significantly (P < 0.05) lower in patients with esophagitis and in subjects taking proton pump inhibitors compared with subjects off (any) treatment. Percentiles of IB in proximal and distal Chs were provided according to different age groups.

CONCLUSIONS

IB is significantly lower in infants (especially in the first months of life) compared with older children. Low IB in both proximal and distal esophagus in young infants may be related to anatomical and functional difference other than the presence of esophagitis.

Pathophysiology of gastro-esophageal reflux disease: a role for mucosa integrity?

BACKGROUND

Gastro-esophageal reflux disease (GERD) is very prevalent and has a high burden on health security system costs. Nevertheless, pathophysiology is complex and not well-understood. Several mechanisms have been proposed: decreased salivation, impaired esophageal clearance, decreased lower esophageal sphincter pressure resting tone, presence of hiatal hernia, increased number of transient lower esophageal sphincter relaxations (TLESRs), increased acid, and pepsin secretion, pyloric incompetence provoking duodeno-gastro-esophageal reflux of bile acids and trypsin. Independent of the relevance of each mechanism, the ultimate phenomenon is that mucosal epithelium is exposed for a longer time to agents as acid and pepsin or is in contact to luminal agents not commonly present in gastric refluxate as trypsin or bile acids. This leads to a visible damage of the epithelium (erosive esophagitis -EE) or impairing mucosal integrity without any sign of macroscopic alteration as occurs in non-erosive reflux disease (NERD). Luminal factors are not the only responsible for such impairment; more recent data indicate that endogenous factors may also play a role.

PURPOSE

This review will update the most recent findings on the putative pathophysiological mechanisms and specially will focus on the role of esophageal mucosal integrity in GERD. Methodologies used for the evaluation of mucosal integrity, its relevance in EE and NERD, its involvement in symptoms perception and the effect of luminal and endogenous factors will be discussed.

Efficacy and safety of once-daily esomeprazole for the treatment of gastroesophageal reflux disease in neonatal patients

OBJECTIVE

To evaluate the efficacy and safety of proton pump inhibitors in infants aged <1 year with gastroesophageal reflux disease (GERD).

STUDY DESIGN

In this randomized, double-blind, placebo-controlled multicenter study, neonates (premature to 1 month corrected age; n = 52) with signs and symptoms of GERD received esomeprazole 0.5 mg/kg or placebo once daily for up to 14 days. Change from baseline in the total number of GERD symptoms (from video monitoring) and GERD-related signs (from cardiorespiratory monitoring) was assessed with simultaneous esophageal pH, impedance, cardiorespiratory, and 8-hour video monitoring.

RESULTS

There were no significant differences between the esomeprazole and placebo groups in the percentage change from baseline in the total number of GERD-related signs and symptoms (-14.7% vs -14.1%, respectively). Mean change from baseline in total number of reflux episodes was not significantly different between esomeprazole and placebo (-7.43 vs -0.2, respectively); however, the percentage of time pH was <4.0 and the number of acidic reflux episodes >5 minutes in duration was significantly decreased with esomeprazole vs placebo (-10.7 vs 2.2 and -5.5 vs 1.0, respectively; P ≤ .0017). The number of patients with adverse events was similar between treatment groups.

CONCLUSIONS

Signs and symptoms of GERD traditionally attributed to acidic reflux in neonates were not significantly altered by esomeprazole treatment. Esomeprazole was well tolerated and reduced esophageal acid exposure and the number of acidic reflux events in neonates.

Oesophageal baseline impedance values are decreased in patients with eosinophilic oesophagitis

BACKGROUND

Gastro-oesophageal reflux has been suggested to play a role in eosinophilic oesophagitis (EoO). Oesophageal acid exposure decreases baseline intraluminal impedance, a marker of mucosal integrity, in patients with gastro-oesophageal reflux disease (GORD).

OBJECTIVES

The aim of this study was to assess oesophageal baseline impedance levels in EoO patients and to investigate their relationship with oesophageal acid exposure.

METHODS

Ambulatory 24-h pH-impedance monitoring was performed in 11 EoO patients and in 11 healthy controls with matched oesophageal acid exposure. We assessed baseline impedance levels in the distal, mid-, and proximal oesophageal impedance channels.

RESULTS

BASELINE IMPEDANCE LEVELS IN EOO PATIENTS WERE MARKEDLY LOWER COMPARED TO CONTROLS IN THE DISTAL OESOPHAGUS (MEDIAN (INTERQUARTILE RANGE): 988 (757-1978) vs. 2259 (1767-2896) Ω, p = 0.015), mid-oesophagus (1420 (836-2164) vs. 2614 (2374-3879) Ω, p = 0.003), and proximal oesophagus (1856 (1006-2625) vs. 2868 (2397-3439) Ω, p = 0.005). Whereas baseline impedance decreased from proximal to distal in healthy subjects (p = 0.037), no such gradient was seen in EoO patients (p = 0.123).

CONCLUSIONS

Throughout the oesophagus, baseline impedance values are decreased in EoO patients, indicating impaired mucosal integrity. Our findings suggest that factors other than acid reflux are the cause of low baseline impedance in EoO.

Baseline esophageal impedance according to different time intervals

Baseline impedance (BImp) reflects esophageal integrity. The study aims to identify the optimal method to calculate BImp. Mean BImp was calculated in 20 consecutive multichannel intraluminal impedance recordings including and excluding impedance events (IEs) (reflux, swallows, and gas episodes) in all channels during the full recording and during the first period of 1 minute without an IE every hour (method 1), every 2 hours (method 2), or 4 hours (method 3). BImp obtained during the total recording was set at 100%, and the variation (difference in BImp for the different methods) and variability (difference in BImp during one analysis period) were assessed. All children underwent endoscopy. No child had esophagitis. The mean difference over the six channels, in percentage, between BImp over the total recording with and without IE was ≈ 1.2% and comparable for each channel (range -5.87-6.99%). A mean of 980 IE were excluded in each tracing, and it took between 4 and 24 hours to delete all events in one tracing. The difference of BImp obtained with and without IE was mainly caused by the gas episodes at the upper and swallows in the lower channel. The mean BImp according to the three 1-minute analysis methods was comparable with the mean BImp according to the 24-hour analysis. The automatic determination of the mean BImp over the total tracing including the IE is an adequate method. In isolated tracings with numerous IE, the calculation of the mean BImp over 1 minute every 4 hours is an alternative option. Companies should develop software to calculate the mean BImp during the whole registration deleting all IE for the analysis.

The role of baseline impedance as a marker of mucosal integrity in children with gastro esophageal reflux disease

OBJECTIVES

Diagnosis of gastro esophageal reflux disease (GERD) in children is challenging. 24-h-pH-multichannel-intraluminal-impedance measurement (pH-MII) is the best diagnostic tool to display gastro esophageal reflux whereas esophageal endoscopy indicates mucosal lesions. The aim of this study was to compare esophageal endoscopy results with reflux parameters such as acid exposure time (reflux index RI), bolus exposure time (bolus index BI), baseline impedance level (BIL) detected by pH-MII in children with suspected GERD.

METHODS

Analysis of data from 285 children (38 infants) referred to our hospital with suspected GERD. Division into three 'reflux esophagitis' (RE)-stages depending on the severity of endoscopic and histological findings and comparison with reflux parameters in these stages. Further categorization into four groups based on the pH-MII-results.

RESULTS

Children with high-grade esophagitis had a significantly lower BIL; otherwise there was no significant association between elevated reflux parameters and esophagitis. Pathological pH-MII results (RI and BI) were associated with lower BIL in the distal impedance channel. The BIL was significantly lower in infants compared to children >1 year regardless of the RI or BI. The main difference between these groups regarding reflux parameters was a longer BI and a higher number of retrograde bolus movements.

CONCLUSION

Pathologic pH-MII results are not predictive for an erosive esophagitis and vice versa. Therefore, these two procedures cannot replace each other. A lower BIL is associated with esophagitis ≥ LA-grade B and may be caused by longer acid but also by longer bolus exposure and thus may be another useful parameter in GERD monitoring.

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.

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.

Effect of proton pump inhibition on acid, weakly acid and weakly alkaline gastro-esophageal reflux in children

BACKGROUND

The effect of proton pump inhibitors on the characteristics of gastroesophageal reflux (GER) in children and adolescents was evaluated.

METHODS

Twenty-one children and adolescents with symptoms suggesting GER disease (GERD) underwent upper endoscopy and a 24-hour multichannel intraluminal impedance/pH (MII-pH) monitoring before and at the end of 2 months of therapy with proton pump inhibitors (PPIs).

RESULTS

Fourteen (67%) patients reported clinically relevant symptom improvement after 2 months of PPIs intake. At the first endoscopy, 8 (38%) patients had macroscopic signs of reflux esophagitis; after two months of therapy, 6/8 (75%) patients had a complete mucosal recovery. There was a significant reduction in the total percentage of mean acid reflux time (from 13.1% to 3.8%), and the De Meester score dropped to normal (from 46.4 to 13.1). The mean number of acid refluxes decreased significantly from 48 to 15 per 24 hours, while inversely, the mean number of weakly acid refluxes increased significantly from 26 to 64 per 24 hours. PPI therapy did not affect the total number of reflux episodes, the number of liquid and mixed refluxes, the duration of esophageal bolus exposure and proximal extent of the reflux.

CONCLUSIONS

In children and adolescents with GERD, PPIs do not affect the total number of reflux episodes. PPIs only decrease the acidity of refluxate. Nevertheless, the majority of patients with typical reflux symptoms may report symptom improvement. Esophagitis can be healed after PPI treatment. The treatment of weakly acid and weakly alkaline reflux remains a challenge for physicians in the future.

Use of direct, endoscopic-guided measurements of mucosal impedance in diagnosis of gastroesophageal reflux disease

BACKGROUND & AIMS

Diagnostic tests for gastroesophageal reflux disease (GERD) are constrained because measurements are made at a single time point, so the long-term effects on the mucosa cannot be determined. We developed a minimally invasive system to assess changes in esophageal mucosal impedance (MI), a marker of reflux. We measured the extent of changes in MI along the esophagus and show that the device to assess MI can be used to diagnose patients with GERD.

METHODS

A single-channel MI catheter composed of a unique sensor array was designed to easily traverse the working channel of an upper endoscope. We performed a prospective longitudinal study of patients with erosive esophagitis (n = 19), nonerosive but pH-positive GERD (n = 23), and those without GERD (n = 27). MI was measured at the site of esophagitis as well as 2, 5, and 10 cm above the squamocolumnar junction. The MI values were compared among groups, at different levels along the esophageal axis.

RESULTS

Median MI values were significantly lower at the site of erosive mucosa (811 Ω; range, 621-1272 Ω) than other nonerosive regions (3723 Ω; range, 2421-4671 Ω; P = .001), and were significantly lower at 2 cm above the squamocolumnar junction in patients with GERD (2096 Ω; range, 1415-2808 Ω), compared with those without GERD (3607 Ω; range, 1973-4238 Ω; P = .008). There was a significant and graded increase in MI along the axis of the distal to proximal esophagus in patients with GERD that was not observed in individuals without reflux (P = .004).

CONCLUSIONS

Measurements of MI along the esophagus can be used to identify patients with GERD. ClinicalTrials.gov, number NCT01194323.

Relationship between baseline impedance levels and esophageal mucosal integrity in children with erosive and non-erosive reflux disease

BACKGROUND

Baseline impedance measurement has been reported to be related to esophageal acid exposure and hypothesized to be a marker of microscopic changes of the esophageal mucosa. Aims of the study were to establish whether any relationship existed between the magnitude of intercellular space diameter (ISD) of esophageal mucosa and baseline impedance levels in children with gastro-esophageal reflux disease (GERD), and to compare baseline impedance levels between children with non erosive (NERD) and erosive (ERD) reflux disease.

METHODS

Fifteen children (median age: 11.2 years) with NERD, and 11 with ERD (median age: 9.6 years) were prospectively studied. All patients underwent upper endoscopy. Biopsies were taken 2-3cm above the Z-line, and ISD was measured using transmission electron microscopy. All patients underwent impedance pH-monitoring, and baseline impedance levels were assessed in the most distal impedance channel.

KEY RESULTS

Mean (±SD) ISD did not differ between NERD (1.0±0.3μm) and ERD (1.1 ± 0.3 μm, ns). Considering all patients together, no correlation was found between distal baseline impedance and ISD (r: -0.15; ns). Conversely, negative correlations were found between distal baseline impedance and acid exposure time (r: -0.76; P<0.001), long-lasting reflux episodes (r: -0.78; P<0.001), acid reflux episodes (r: -0.62; P<0.001), and acid clearance time (r: -0.79; P<0.001). Distal baseline impedance was significantly lower in ERD [1455 (947-2338) Ω] than in NERD children [3065 (2253-3771) Ω; P<0.01].

CONCLUSIONS & INFERENCES

  In children with GERD baseline impedance levels are not useful in predicting reflux-induced ultrastructural changes in the esophageal mucosa, despite their ability to discriminate between NERD and ERD.

Clinical applications of esophageal impedance monitoring and high-resolution manometry

Esophageal impedance monitoring and high-resolution manometry (HRM) are useful tools in the diagnostic work-up of patients with upper gastrointestinal complaints. Impedance monitoring increases the diagnostic yield for gastroesophageal reflux disease in adults and children and has become the gold standard in the diagnostic work-up of reflux symptoms. Its role in the work-up for belching disorders and rumination seems promising. HRM is superior to other diagnostic tools for the evaluation of achalasia and contributes to a more specific classification of esophageal disorders in patients with non-obstructive dysphagia. The role of HRM in patients with dysphagia after laparoscopic placement of an adjustable gastric band seems promising. Future studies will further determine the clinical implications of the new insights which have been acquired with these techniques. This review aims to describe the clinical applications of impedance monitoring and HRM.

Indications, methodology, and interpretation of combined esophageal impedance-pH monitoring in children: ESPGHAN EURO-PIG standard protocol

AIM

The aim of the study was to provide an updated position statement from the ESPGHAN European Pediatric Impedance Working Group on different technical aspects such as indications, methodology, and interpretation of multichannel intraluminal impedance-pH monitoring (MII-pH).

METHODS

Evidence was used where available, but the article is based mainly on expert opinion and consensus.

RESULTS

MII-pH provides more information than simple pH monitoring because reflux detection is not limited to acid reflux. Different companies provide commercialized MII-pH recording systems, making the method widely available and useable in daily clinical practice; however, the technique still has limitations: high cost, limited additional value regarding therapeutic implications, and lack of evidence-based parameters for the assessment of gastroesophageal reflux and symptom association in children.

CONCLUSIONS

MII-pH recording is a promising procedure needing further validation and development to increase its additional benefit over conventional investigation techniques. The added value of the technique regards mainly clinical circumstances in which nonacid or weakly acid reflux may be relevant such as persisting symptoms during antireflux treatment with proton pump inhibitors and feeding-related reflux; and assessing specific discontinuous symptoms thought to be associated with gastroesophageal reflux; and research.

Esophageal impedance baselines in infants before and after placebo and proton pump inhibitor therapy

BACKGROUND

Esophageal impedance monitoring records changes in conductivity. During esophageal rest, impedance baseline values may represent mucosal integrity. The aim of this study was to assess the influence of acid suppression on impedance baselines in a placebo-controlled setting.

METHODS

Impedance recordings from 40 infants (0-6 months) enrolled in randomized placebo-controlled trials of proton pump inhibitor (PPI) were retrospectively analyzed. Infants underwent 24 h pH-impedance monitoring prior to and after 2 weeks of double blind therapy with placebo or a PPI. Typical clinical signs of gastro-esophageal reflux (GER) were recorded and I-GERQ-R questionnaire was completed.

KEY RESULTS

Median (IQR) impedance baseline increased on PPI treatment (from 1217 (826-1514) to 1903 (1560-2194) Ω, P < 0.001) but not with placebo (from 1445 (1033-1791) to 1650 (1292-1983) Ω, P = 0.13). Baselines before treatment inversely correlate with the number of GER, acid GER, weakly acid GER, acid exposure, and symptoms. The change in baseline on treatment inversely correlates with acid exposure and acid GER. Patients with initial low baselines have no improved symptomatic response to treatment.

CONCLUSIONS & INFERENCES

Impedance baselines are influenced by GER and increase significantly more with PPI therapy than with placebo. Clinical impact of this observation remains undefined as targeting therapy at infants with low baselines does not improve symptomatic response to treatment.

Esophageal impedance baseline according to different time intervals

Background

The impedance baseline has been shown to reflect esophageal integrity, and to be decreased in patients with esophagitis. However, different methods for the determination of the impedance baseline have not been compared.

Methods

The median impedance baseline was calculated in 10 consecutive multichannel intraluminal impedance recordings in children with non-erosive reflux disease. All children underwent an endoscopy with a biopsy as part of the clinical work-up to exclude esophagitis. The impedance baseline was obtained both by including and excluding all impedance episodes (IE; reflux, swallows and gas episodes) during the full recording, and during the first 1-minute period without an IE every hour (method 1), every 2 hours (method 2) or every 4 hours (method 3). The impedance baseline obtained during the full recording was set at 100%, and the variation (difference in impedance baseline for the different methods) and variability (difference in impedance baseline during one analysis period) were assessed.

Results

None of the participants had esophagitis. The mean difference over the six channels between the impedance baseline over the total recording with and without IE was approximately 2.5%, and comparable for each channel (range 0.47% to 5.55%). A mean of 1,028 IEs were excluded in each tracing, and it took between 4 and 24 hours to delete all events in one tracing. The difference in the impedance baseline obtained with and without IEs was mainly caused by the gas episodes in the upper channels and swallows in the lower channels. The median impedance baseline according to the three one-minute analysis methods was comparable to the median impedance baseline according to the 24 hour analysis.

Conclusions

The automatic determination of the median impedance baseline over the total tracing including IEs is an adequate method. In isolated tracings with numerous IEs, the calculation of the median impedance baseline over one minute every 4 hours is an alternative option. Companies should develop software to calculate the median impedance baseline during the whole registration deleting all IEs for the analysis.