New technologies for the evaluation of esophageal motility disorders: impedance, high-resolution manometry, and intraluminal ultrasound

New technologies have been introduced for studying esophageal function, including intraluminal impedance and ultrasound, whereas conventional techniques, such as manometry, have undergone substantial upgrades because of advances in transducer technology, computerization, and graphic data presentation. Although these techniques provide both novel and more detailed information regarding esophageal function, it is still unclear whether they have improved the ability to diagnose and treat patients more effectively. Regardless, they are innovative research tools and they have added substantially to the understanding of the pathophysiology of dysphagia and esophageal motor dysfunction. This article describes the technical aspects of each of these technologies and the potential benefits they offer over conventional techniques for the evaluation of esophageal motor diseases.     

Preoperative physiological esophageal assessment for anti-reflux surgery: A guide for surgeons on high-resolution manometry and pH testing

Gastroesophageal reflux disease (GERD) is one of the most commonly encountered digestive diseases in the world, with the prevalence continuing to increase. Many patients are successfully treated with lifestyle modifications and proton pump inhibitor therapy, but a subset of patients require more aggressive intervention for control of their symptoms. Surgical treatment with fundoplication is a viable option for patients with GERD, as it attempts to improve the integrity of the lower esophageal sphincter (LES). While surgery can be as effective as medical treatment, it can also be associated with side effects such as dysphagia, bloating, and abdominal pain. Therefore, a thorough pre-operative assessment is crucial to select appropriate surgical candidates. Newer technologies are becoming increasingly available to help clinicians identify patients with true LES dysfunction, such as pH-impedance studies and high-resolution manometry (HRM). Pre-operative evaluation should be aimed at confirming the diagnosis of GERD, ruling out any major motility disorders, and selecting appropriate surgical candidates. HRM and pH testing are key tests to consider for patients with GERD like symptoms, and the addition of provocative measures such as straight leg raises and multiple rapid swallows to HRM protocol can assess the presence of underlying hiatal hernias and to test a patient’s peristaltic reserve prior to surgery.     

Multichannel intraluminal impedance in esophageal function testing and gastroesophageal reflux monitoring

Multichannel intraluminal impedance (MII) is a new technique for evaluating esophageal function and gastroesophageal reflux. This technique depends on changes in resistance to alternating current between two metal electrodes produced by the presence of bolus inside the esophageal lumen. Combined MII and manometry (MII-EM) provides simultaneous information on intraluminal pressure changes and bolus movement, whereas combined MII and pH (MII-pH) allows detection of pH episodes irrespective of their pH values (ie, acid and non-acid reflux). Combined MII-EM studies are performed very similarly to standard manometry. Based on studies in healthy volunteers and patients, combined MII-EM challenges current existing criteria that define the effectiveness of esophageal body function. Combined MII-pH testing brings a shift in gastroesophageal reflux testing paradigm. In MII-pH studies, reflux events are no longer detected by pH. Refluxate presence, distribution, and clearing are primarily detected by MII and simply characterized as acid versus non-acid based on pH change and as liquid, gas, or mixed based on MII. MII determines refluxate clearance time, whereas pH measures acid clearance time. MII-pH shows promise to become an important clinical tool, particularly to assess gastroesophageal reflux in the postprandial period and in patients with persistent symptoms on therapy and with atypical symptoms.     

Safety aspects of ambulant esophageal manometry and pH monitoring

Nonperfused piezoresistive pressure transducers and ISFET (ion-sensitive field effect transistors) pH electrodes are increasingly used for research purposes and during ambulatory patient monitoring. The currently used multichannel dataloggers are usually powered by batteries with a voltage range of approximately 3–9 V. Piezoresistive pressure transducers need an excitation voltage between 0.5 and 2.0 V (constant voltage powered) or an excitation current of 0.5–2 mA (constant current powered). ISFET pH electrodes are characterized by the need of a wide range of supply voltages (–3 to +3 V). These transducers normally are employed in endoluminal multisensor catheters, possibly with an external reference electrode, which implies a galvanic coupling of the logger system with the patient. In the case of a loss of insulation of one or more of the sensors, net currents of up to several milliamps can occur, depending on the relative placement of the sensors and/or the reference electrode. It is conceivable that these currents can induce cardiac arrhythmias and even fibrillation. To prevent these potential problems, we have developed an eight-channel ambulant datalogger incorporating a safety circuitry to check for current leakage from each sensor. If leakage occurs, an automatic galvanic separation of the defective transducer is effected This was achieved using a hardware design independent of the processor. The threshold of deactivation is chosen according to national regulations [10 A in the United States (UL, Underwriters Laboratories Inc.) and 100 A in the EEC (DIN IEC-601, International Electrotechnical Commission)].     

Impact of patient position on esophageal motility disorders using high-resolution esophageal manometry with impedance (HREMI): supine versus upright swallows

Esophagus - High-resolution esophageal manometry with impedance (HREMI) performed with supine patient positioning is used to evaluate patients for esophageal dysmotility. However, most patients...     

Evaluation of esophageal motor disorders in the era of high-resolution manometry and intraluminal impedance

The past few years were an exciting time in the study of esophageal motor disorders because new technologies emerged to study esophageal motor function and bolus transit. Although conventional manometry was long considered the “gold standard” for defining esophageal motor disorders, many technologic improvements occurred due to advances in transducer technology, computerization, and graphic data presentation. In addition, a relatively new technology, intraluminal impedance, was incorporated into manometric modalities. The most sophisticated systems now include combined high-resolution manometry with high-resolution impedance. Although these techniques provide more detailed information about esophageal function, whether they improve our ability to diagnose and treat patients more effectively is debatable. However, more recent data support that these advances actually improve our ability to diagnose and treat esophageal motor disorders. This article provides an update on these technologies in clinical practice and how they may be helpful in the future.     

Characteristics and clinical relevance of proximal esophageal pH monitoring

OBJECTIVE: It is well established that various ENT disorders and symptoms may be a manifestation of gastroesophageal reflux disease (GERD). Measuring proximal esophageal acid exposure might be useful in the evaluation of patients with suspected reflux-related ENT manifestations, but the limited available data are conflicting. The aim of the present study was to study the determinants of proximal esophageal acid exposure (PR) and to evaluate the clinical usefulness of ambulatory proximal pH monitoring. METHODS: Twenty healthy controls and 346 patients with suspected reflux disease underwent typical and atypical GERD symptom assessment, endoscopy, esophageal manometry and ambulatory combined dual esophageal pH, and Bilitec duodeno-gastro-esophageal reflux exposure (DGER) monitoring. The presence of pathological PR and its relation to symptom pattern and distal esophageal acid exposure (DR) and DGER exposure were analyzed. RESULTS: Fifty-seven patients (16%) had pathological PR. Demographic characteristics, symptom pattern, and manometric findings did not differ in patients with normal or pathological PR. Patients with pathological PR had significantly higher DR and DGER. The multivariate analysis identified only pathological DR as an independent risk factor for the presence of pathological PR (odds ratio 4.515, 95% CI 2.48-8.23, p < 0.0001). Only 20 patients (6%) had pathological proximal reflux without pathological distal acid reflux. CONCLUSION: The findings of the present article do not support routine proximal esophageal pH monitoring as a clinical tool: PR does not differentiate patients with typical or atypical GERD manifestations and depends mainly on DR.     

Advancements in the use of manometry and impedance testing for esophageal functional disorders

Introduction. The utilization of high-resolution manometry (HRM) has enhanced our understanding and assessment of esophageal motor disorders. Moreover, the combination of impedance technology with HRM (HRIM) has further improved our knowledge of esophageal physiology and the clinical evaluation of dysmotility, thanks to the addition of accurate measurement of bolus transit.

Areas covered. This paper provides an overview of current knowledge in the use of HRIM for the study of esophageal functional disorders by reporting mainly the results of many publications and several systematic reviews in this field.

Expert opinion. HRIM has represented a relevant improvement in the assessment of esophageal motility and has required the development of new metrics, such as the esophageal impedance integral ratio, the bolus flow time, the nadir impedance pressure and the impedance bolus height, which increase the evaluation of esophageal bolus transit. An extension of impedance is represented by functional lumen imaging probe (FLIP), which determines the biophysical properties and the distensibility of the esophagus and permits to detect contractility patterns not seen on HRM alone. We eagerly wait for a new and fruitful iteration of the Chicago Classification, now in version 3.0, which can cover the ongoing clinical experience of HRIM.     

Combined multichannel intraluminal impedance and manometry clarifies esophageal function abnormalities: study in 350 patients

BACKGROUND: Combined multichannel intraluminal impedance and esophageal manometry (MII-EM) is a technique that uses an FDA-approved device allowing simultaneous evaluation of bolus transit (MII) in relation to pressure changes (EM). METHODS: During a 9-month period, beginning from July 2002 through March 2003, we prospectively performed combined MII-EM on all patients referred for esophageal function testing. Each patient received 10 liquid and 10 viscous swallows. Manometric findings were reported based on criteria described by Spechler and Castell for liquid swallows. MII findings were reported as having normal bolus transit if >/=80% (8/10) of liquid and >/=70% (7/10) of viscous swallows had complete bolus transit. RESULTS: Three-hundred fifty studies were evaluated from patients with a variety of symptoms having the following manometric diagnoses: normal manometry (125), achalasia (24), scleroderma (4), ineffective esophageal motility (IEM) (71), distal esophageal spasm (DES) (33), nutcracker esophagus (30), hypertensive lower esophageal sphincter (LES) (25), hypotensive LES (5), and poorly relaxing LES (33). None of the patients with achalasia and scleroderma had normal bolus transit. Fifty-one percent of patients with IEM and 55% of patients with DES had normal bolus transit while almost all (more than 95%) patients with normal esophageal manometry, nutcracker esophagus, poorly relaxing LES, hypertensive LES, and hypotensive LES had normal bolus transit. Dysphagia occurred most often in patients with incomplete bolus transit on MII testing. CONCLUSION: Esophageal body pressures primarily determine bolus transit with isolated LES abnormalities appearing to have little effect on esophageal function. MII clarifies functional abnormalities in patients with abnormal manometric studies.     

Comparison of the Bravo wireless and Digitrapper catheter-based pH monitoring systems for measuring esophageal acid exposure

INTRODUCTION: We compared esophageal acid exposure data obtained during simultaneous esophageal pH studies using the Bravo wireless and the Slimline catheter-Mark III Digitrapper pH systems. METHODS: Twenty-five asymptomatic subjects underwent endoscopy with endoclip placement at the squamocolumnar junction (SCJ) and manometry to localize the lower esophageal sphincter (LES). A Bravo capsule was placed 6 cm above the SCJ and a Slimline catheter 5 cm above the LES. Relative positions were checked fluoroscopically. Synchronized pH data were compared by manual extraction into Excel spreadsheets. An in vivo pH reference was established with swallows of orange juice (pH 3.88). RESULTS: Median acid exposure time was greater with the Slimline compared to the Bravo system (Slimline, 3.4%; Bravo, 1.76%, p < 0.05) but electrode positions were similar. The dominant source of discrepancy between systems was an offset in recorded pH values around pH 4 as evidenced by the recorded values of the swallowed orange juice. Bench-top testing suggested that this offset was mainly attributable to the software designed to compensate for the difference in electrode recording characteristics between room and body temperature. After adjusting the pH data sets to accurately reflect actual orange juice pH, acid exposure between systems was similar (Slimline, 0.90%; Bravo, 1.15%). CONCLUSION: The Slimline system on average over-recorded esophageal acid exposure compared to the Bravo system largely because of a flawed software scheme for electrode thermal calibration. Accuracy of pH data sets from both systems can be improved by scrutiny for artifacts and use of an in vivo pH reference.     

Comparison of esophageal manometry,provocative testing,and ambulatory monitoring in patients with unexplained chest pain

Prolonged ambulatory esophageal pH and pressure monitors are being developed to evaluate noncardiac chest pain. This new technology needs comparison with conventional esophageal tests before determining which studies are most useful in diagnosing and treating esophageal chest pain. Therefore, we studied 45 patients with esophageal manometry, acid perfusion and edrophonium tests, and 24 hr pH and pressure monitoring. Manometry was abnormal in 20 patients (44%) with nutcracker esophagus, the most common motility disorder. Fifteen (33%) had positive acid perfusion test and 24 (55%) positive edrophonium test. During ambulatory monitoring, all patients experienced chest pain with a total of 202 individual events: 32 events (15%) secondary to acid reflux, 15 (7%) secondary to motility abnormalities, 7 (3%) to both pH and pressure changes, and 149 events (74%) occurred in the absence of any abnormal pH or motility changes. Patients with normal manometry were significantly (P less than 0.01) more likely to have acid reflux chest pain events than did nutcracker patients, who had an equal frequency of pH and motility events. A positive acid perfusion test was significantly associated with abnormal pressure events (P = 0.02; odds ratio 5.95), while a positive edrophonium test more likely predicted acid reflux chest pain during 24-hr monitoring (P = 0.007; odds ratio 7.25). Therefore, abnormal manometry and positive provocative tests point to the esophagus as the likely source of chest pain. However, ambulatory pH and pressure monitoring are required to accurately define the relationship between chest pain and acid reflux or motility disorders.(ABSTRACT TRUNCATED AT 250 WORDS)     

水灌注高分辨率食管测压及24 h pH-阻抗监测在GERD诊断中的应用价值研究

目的探索水灌注高分辨率食管测压及24 h pH-阻抗监测在胃食管反流病(GERD)诊断中的应用价值研究。 方法回顾性分析2014年9月至2015年7月,贵州省兴义市人民医院就诊的慢性浅表性胃炎患者为研究对象。对患者进行水灌注导管高分辨率食管测压和pH-阻抗监测即反流监测,鉴别其是否存在GERD。 结果经胃镜检查后,无论是否存在典型症状,患者均为慢性浅表性胃炎;从液态高分辨率食管测压结果来看,典型症状和非典型症状的LES压力,UES压力以及食管体部功能,胃食管连接处出口梗阻,胡桃夹食管以及食管裂孔疝情况比较,差异无统计学意义(P>0.05)。从24 h pH-阻抗监测结果来看,典型症状和非典型症状的反酸次数,所有反流次数和非反酸次数比较,差异无统计学意义(P>0.05)。 结论通过本研究提示,胃食管反流病作为消化科的常见病、多发病,通过水灌注高分辨率食管测压、24 h pH-阻抗监测联合胃镜检查,能够提高食管反流病的诊断率,减少依靠症状诊断的误诊率,特别是在临床工作中,需要与反复发作的慢性胃炎进行鉴别诊断,只有在明确诊断后,才能进行有效的治疗,最终达到缓解患者不适症状的目的,提高治愈率。     

Esophageal function testing with combined multichannel intraluminal impedance and manometry: multicenter study in healthy volunteers.

BACKGROUND & AIMS: Combined multichannel intraluminal impedance and manometry (MII-EM) assesses esophageal function by simultaneous measurement of both pressure and bolus transit. Normative data for this method have not been published. The aim of this study was to establish normative data for combined MII-EM and to correlate liquid and viscous bolus transit by impedance with esophageal contractions by manometry. METHODS: Forty-three normal volunteers recruited from 4 centers (15 women, 28 men; age range, 21-72 years) underwent combined MII-EM with a catheter containing 4 impedance-measuring segments and 4 solid-state pressure transducers. Each center recruited and analyzed subjects independently, according to pre-established criteria. Each subject received 20 x 5 mL swallows, 10 liquid and 10 viscous material. Tracings were analyzed manually for bolus presence time, bolus head advance time, segmental transit times, total bolus transit time, contraction amplitude, duration, and onset velocity. RESULTS: Ninety-seven and four-tenths percent of manometrically normal liquid and 96.1% of manometrically normal viscous swallows had complete bolus transit by impedance. Almost half (47.2%) of manometrically ineffective liquid and 34.7% of ineffective viscous swallows had complete bolus transit, whereas 91.7% of manometric simultaneous liquid swallows and 54.5% of simultaneous viscous swallows had complete bolus transit. More than 93% of normal individuals had at least 80% complete liquid or at least 70% complete viscous bolus transit. CONCLUSIONS: This study establishes normative data for combined MII-EM. Combined MII-EM may be a more sensitive tool in assessing esophageal function compared to standard manometry because impedance can distinguish different bolus transit patterns. Studies in patients with manometrically defined esophageal motility abnormalities should help clarify the functional importance of manometric ineffective and simultaneous swallows.     

Simultaneous recordings of oesophageal acid exposure with conventional pH monitoring and a wireless system (Bravo)

OBJECTIVES: Oesophageal pH monitoring is a useful test for the diagnosis of gastro-oesophageal reflux disease (GORD) but has some limitations related to the nasopharyngeal electrode. Recently, a telemetric catheter free system (CFS) (Bravo; Medtronic) was developed. The aim of this study was to determine the concordance of data between the conventional pH measurement system (CPHMS) and the CFS Bravo. METHODS: Forty patients with symptoms suggestive of GORD underwent 24 hour oesophageal pH monitoring using the CPHMS with a nasopharyngeal electrode and the Bravo CFS simultaneously. The sensitive tips of both electrodes were positioned at the same level under fluoroscopy. In addition to automatic analysis, each reflux episode was checked visually and characterised. RESULTS: There was a significant correlation (r = 0.87, p < 0.0001) between the 24 hour oesophageal acid exposures recorded by the CPHMS and the CFS. Twenty four hour oesophageal acid exposure was significantly lower with the CFS than with the CPHMS (2.4 (0.4-8.7) v 3.6 (0.7-8.6); p < 0.0001). Consequently, with the CFS, the cut off level for the diagnosis of GORD, as calculated from the regression equation, was 2.9% (for the 4.2% cut off determined in controls with the CPHMS). After this adjustment, concordance of the diagnosis of GORD was 88% (kappa 0.760). Diagnosis of GORD was established in more patients with the CFS 48 hour results than with the 24 hour results. CONCLUSIONS: Despite strong correlations between oesophageal acid exposure recorded with the two devices, the Bravo CFS significantly under recorded acid exposure compared with the CPHMS. Provided some correcting factors are used, the Bravo CFS can improve the sensitivity of pHmetry for the diagnosis of GORD by allowing more prolonged recordings.     

Esophageal manometry and pH monitoring: gastroenterologists' adherence to published guidelines

GOALS: To determine whether gastroenterologists use esophageal manometry (EM) and esophageal pH recording (pHR) in accordance with published guidelines. STUDY: Questionnaires were mailed to 900 randomly selected gastroenterologists nationwide. Each questionnaire requested demographic information and contained 11 case scenario-based questions, followed by a choice of management options. RESULTS: A total of 275 completed questionnaires (30.6%) were returned. 63.6% and 64.4% of respondents were aware of published guidelines regarding the use of EM and pHR, respectively. The majority of respondents ordered EM appropriately: 1) to confirm a suspected diagnosis of achalasia (97.1%); 2) to establish a diagnosis of connective tissue disease (89.7%); 3) as part of the preoperative evaluation for anti-reflux surgery (74.6%); and 4) to ensure the proper placement of pH probes (69.4%). EM was rarely ordered for the initial workup of noncardiac chest pain. The majority of responding gastroenterologists would order pHR for the evaluation of: 1) endoscopy-negative patients being considered for anti-reflux surgery (79.1%); 2) patients with recurrent GERD symptoms after anti-reflux surgery (62.5%); 3) endoscopy-negative patients with GERD symptoms refractory to proton pump inhibitor (PPI) therapy; and 4) patients with extraesophageal manifestations of GERD that are refractory to PPI therapy (88.7%). CONCLUSIONS: The majority of gastroenterologists in our study order EM and pHR in accordance with published guidelines. However, EM appears to be used less than expected for preoperative evaluation before anti-reflux surgery and for ensuring the proper placement of pH probes. In addition, the use of pHR to evaluate persistent GERD symptoms after anti-reflux surgery was less than anticipated.     

Technological insights： Combined impedance manometry for esophageal motility testing-current results and further implications

INTRODUCTION The basic function of the esophagus is the transport of the bolus from the pharynx into the stomach. Esophageal peristalsis is based on propulsive mechanisms along the axis of the organ, generated by a latency gradient that is modulated by th…     

Multichannel intraluminal impedance and esophageal manometry data for unrestricted swallowing: establishing normal values

SUMMARY.    Standard esophageal manometric testing evaluates swallowing in the supine position using small boluses, with a recovery period imposed between swallows. Manometric tests of more physiologic unrestricted swallowing have had limited practical application due to highly variable results. The purpose of this study is to apply multichannel intraluminal impedance and manometry (MII-EM) to test esophageal function during unrestricted upright meal consumption, and to assess results in a normal healthy population. Ten healthy volunteers with normal esophageal impedance and manometry by published criteria underwent MII-EM testing using a combined 5-channel catheter. After transnasal placement of the catheter, each subject sat upright and consumed a meal that consisted of two pieces of toasted bread and two ounces of Gatorade. There were no restrictions placed on chewing, swallowing, or eating time. All data assessed by the MII-EM meal test were normally distributed. Impedance results with limited variability included the meal duration, number of swallows, postprandial emptying time and the percent of bolus presence times at 15, 10, and 5 cm above the lower esophageal sphincter. Manometric results with limited variability included the number of peristaltic sequences, mean time between these sequences and their distal esophageal amplitudes. MII-EM can be used to collect data with minimal variability in healthy subjects during unrestricted upright meal consumption. This technique may be used to identify abnormal motility patterns during physiologic swallowing.