Sudip K. Ghosh

Classifying Esophageal Motility by Pressure Topography Characteristics: A Study of 400 Patients and 75 Controls

AIM:This study aimed to devise a scheme for the systematic analysis of esophageal high-resolution manometry (HRM) studies displayed using topographic plotting.METHODS:A total of 400 patients and 75 control subjects were studied with a 36-channel HRM assembly. Studies were analyzed in a stepwise fashion for: (a) the adequacy of deglutitive esophagogastric junction (EGJ) relaxation, (b) the presence and propagation characteristics of distal esophageal persitalsis, and (c) an integral of the magnitude and span of the distal esophageal contraction.RESULTS:Two strengths of pressure topography plots compared to conventional manometric recordings were: (a) the ability to delineate the spatial limits, vigor, and integrity of individual contractile segments along the esophagus, and (b) the ability to distinguish between loci of compartmentalized intraesophageal pressurization and rapidly propagated contractions. Making these distinctions objectified the identification of distal esophageal spasm (DES), vigorous achalasia, functional obstruction, and nutcracker esophagus subtypes. Applying these distinctions made the diagnosis of spastic disorders quite rare: (a) DES in 1.5% patients, (b) vigorous achalasia in 1.5%, and (c) a newly defined entity, spastic nutcracker, in 1.5%.CONCLUSIONS:We developed a systematic approach to analyzing esophageal motility using HRM and pressure topography plots. The resultant scheme is consistent with conventional classifications with the caveats that: (a) hypercontractile conditions are more specifically defined, (b) distinctions are made between rapidly propagated contractions and compartmentalized esophageal pressurization, and (c) there is no “nonspecific esophageal motor disorder” classification. We expect that pressure topography analysis, with its well-defined functional implications, will prove valuable in the clinical management of esophageal motility disorders.

Esophageal motility disorders in terms of pressure topography: the Chicago Classification.

Two recent advances have revolutionized the performance of clinical esophageal manometry; the introduction of practical high resolution manometry (HRM) systems and the development of sophisticated algorithms to display the expanded manometric dataset as pressure topography plots. We utilized a large clinical experience of 400 consecutive patients and 75 control subjects to develop a systematic approach to analyzing esophageal motility using HRM and pressure topography plots. The resultant classification scheme has been named as the Chicago Classification of esophageal motility. Two strengths of pressure topography plots compared with conventional manometric recordings were the ability to (1) delineate the spatial limits, vigor, and integrity of individual contractile segments along the esophagus and (2) to distinguish between loci of compartmentalized intraesophageal pressurization and rapidly propagated contractions. Making these distinctions objectified the identification of distal esophageal spasm, vigorous achalasia, functional obstruction, and nutcracker esophagus subtypes. Applying these distinctions made the diagnosis of spastic disorders quite rare: spasm in 1.5% of patients, vigorous achalasia in 1.5%, and a newly defined entity, spastic nutcracker, in 1.5%. Ultimately, further clinical experience will be the judge, but it is our expectation that pressure topography analysis of HRM data, along with its well-defined functional implications, will prove valuable in the clinical management of esophageal motility disorders.

Esophageal Pressure Topography Criteria Indicative of Incomplete Bolus Clearance: A Study Using High-Resolution Impedance Manometry

OBJECTIVES:This study used high-resolution impedance manometry (HRIM) to determine pressure topography thresholds of peristaltic integrity predictive of incomplete esophageal bolus clearance.METHODS:A total of 16 normal controls and 8 patients with dysphagia were studied using a solid-state HRIM assembly incorporating 36 manometric sensors and 12 impedance segments. Each of the 10 saline swallows in each study was dichotomously scored as either complete or incomplete bolus clearance by impedance criteria, and peristaltic integrity was evaluated using pressure topography isobaric contours ranging from 10 to 30 mm Hg in 5- mm Hg increments. Each isobaric contour plot was characterized by the location and length of breaks in the isobaric contour.RESULTS:All subjects had normal esophagogastric junction (EGJ) relaxation and none met the pressure topography criteria of hiatus hernia. In all, 70 (29%) of the 240 individual swallows had incomplete bolus clearance. In every case, an intact ≥20 mm Hg isobaric contour was associated with complete bolus clearance. The largest defect in the 20 and 30 mm Hg isobaric contours associated with complete bolus clearance measured 1.7 and 3.0 cm, respectively, in length, whereas the smallest defect predictive of incomplete bolus clearance measured 2.1 and 3.2 cm, respectively.CONCLUSIONS:In individuals with normal EGJ relaxation and morphology, peristaltic contractions with breaks <2 cm in the 20 mm Hg isobaric contour or <3 cm in the 30 mm Hg isobaric contour are associated with complete bolus clearance, and longer breaks predict incomplete bolus clearance.

Acidity Surrounding the Squamocolumnar Junction in GERD Patients : Acid Pocket Versus Acid Film

AIM:This study aimed to localize the gastric-to-esophageal pH transition point relative to the squamocolumnar junction (SCJ) and esophagogastric junction (EGJ) high-pressure zone in controls and GERD patients.METHODS:Ten controls and 10 GERD patients were studied. Subjects had an endoclip placed at the SCJ prior to a pH catheter pull-through (upright and supine) during concurrent fluoroscopy before and after consuming a standardized meal. Six controls and 6 GERD patients also underwent concurrent manometry. The relative positions of the SCJ, EGJ high-pressure zone, and pH transition points were analyzed.RESULTS:Most controls and GERD patients exhibited an unbuffered acidified segment in the proximal stomach postprandially. The proximal pH transition point was confined distal to the SCJ in control subjects, regardless of posture or meal state. GERD patients exhibited a more proximal pH transition point, extending above the SCJ and EGJ high-pressure zone in the supine position, especially postprandially. However, the high-pressure zone was intact.CONCLUSION:A short segment of unbuffered acidity of unknown volume exists after meals in the proximal stomach. In controls, the unbuffered acidic segment is contained distal to the SCJ while in the GERD patients it extended into and even across the EGJ high-pressure zone. However, this extension through the EGJ in GERD patients occurred in the context of an intact sphincter suggesting that this is best conceptualized as an acid “film” rather than a “pocket.” This observation may help explain the propensity of the distal esophageal mucosa to lesions of reflux disease.

Acid reflux event detection using the Bravo wireless versus the Slimline catheter pH systems: why are the numbers so different?

Objective: This study analysed the relative accuracy of the Bravo wireless and the Slimline catheter-Mark III Digitrapper pH systems in the detection of acid reflux events. Methods: Twenty five asymptomatic subjects were studied. A Bravo capsule was placed 6 cm above the squamocolumnar junction (SCJ), marked by an endoclip, and a Slimline pH catheter was placed 5 cm above the manometrically localised lower oesophageal sphincter. The distance between the SCJ and each pH electrode was measured fluoroscopically. An in vivo pH reference was established using swallows of orange juice (pH 3.88). Concurrent pH data from the two systems were analysed in Excel spreadsheets. Results: Significantly more acid reflux events were reported by the Digitrapper system than the Bravo system (117.0 v 41.8). This was not explained by electrode position as there was no difference in median distance between the SCJ and either pH electrode (7.25 cm v 7.08 cm). The dominant source of discrepancy between systems was inaccuracy in electrode calibration and, after adjustment using the in vivo orange juice pH measurement, the discrepancy improved by 40%. However, discrepancy still existed and was most pronounced with short reflux events (1–15 s for the catheter, 1–17 s for the Bravo) associated with minimal intraoesophageal acidity and poor concordance between systems. Conclusion: Substantially more reflux events were reported by the Digitrapper system compared with the Bravo system; 40% of excess events were attributable to a flawed software scheme for electrode thermal calibration while most of the remainder were brief events with poor reproducibility between systems.

Oesophageal peristaltic transition zone defects: Real but few and far between

Abstract  This study analysed the association between oesophageal transition zone (TZ) defects [characterized by a delay and/or spatial gap between the terminus of the proximal oesophageal (striated muscle) contraction and the initiation of the distal oesophageal (smooth muscle) contraction] and dysphagia in a large patient cohort. Four hundred consecutive patients (178 with dysphagia) and 75 controls were studied with 36‐channel high‐resolution manometry (HRM). The resultant pressure topography plots were first analysed for impaired oesophagogastric junction (OGJ) relaxation, distal segment contractile abnormalities, and proximal contractile abnormalities using normal values from the 75 controls. If these aspects of oesophageal motility were deemed normal, the TZ was characterized by length and duration between the proximal and distal contractions using a 20 mmHg isobaric contour to establish the segment boundaries. Patients were then classified according to whether or not they exhibited TZ defects (spatial separation or delay) and the occurrence of unexplained dysphagia. Of the 400 patients, 267 were suitable for TZ analysis and of these 55 had a spatial or temporal TZ measurement exceeding the 95th percentile of the controls (2 cm, 1 s). Exactly 34.6% of the patients (n = 19) with spatial and/or temporal TZ defects had unexplained dysphagia, which was significantly more than seen with normal TZ dimensions (19.8%). Although far less common than distal peristaltic or OGJ abnormailites, TZ defects may be related to dysphagia in a minority of patients (<4% in this series) and should be considered a distinct oesophageal motility disorder.

Upper sphincter function during transient lower oesophageal sphincter relaxation (tLOSR); it is mainly about microburps.

Abstract  Transient lower oesophageal sphincter relaxations (tLOSRs) are both a dominant mechanism of reflux and an element of the belch reflex. This study aimed to analyse the interplay between reflux and upper oesophageal sphincter (UOS) activity during meal‐induced tLOSRs. Fifteen normal subjects were studied with a solid‐state high‐resolution manometry assembly positioned to record from the hypopharynx to the stomach and a catheter pH electrode 5 cm above the LOS. Subjects ate a 1000‐calorie high‐fat meal and were monitored for 120 min in a sitting posture. The relationship among tLOSRs, common cavities, pressure changes within the oesophagus and UOS contractile activity were analysed. A total of 218 tLOSRs occurred among the 15 subjects. The majority (79%) were coupled with UOS relaxation and 84% (145/173) of these occurred in association with a common cavity. Upper oesophageal sphincter relaxation was usually preceded by a pressure change in the oesophagus; however, some relaxations (16%) occurred without a discernable increase in pressure or before the pressure increase began. Acid reflux did not appear to play a role in determining UOS response to tLOSRs. The majority of post‐prandial tLOSRs were associated with brief periods of UOS relaxation, likely permissive of gas venting (microburps). Intraoesophageal pressure changes likely modulate this UOS response; however, an anticipatory characteristic was evident in some subjects. Whether or not GORD patients with extra‐oesophageal symptoms exhibit an exaggeration of the UOS relaxation response during reflux is yet to be determined.

Utilizing Intraluminal Pressure Gradients to Predict Esophageal Clearance: A Validation Study

BACKGROUND: Esophageal bolus clearance requires a preferential esophagogastric pressure gradient sustained for a sufficient period. We aimed to validate a high-resolution manometry (HRM) paradigm for predicting bolus clearance.METHODS: Twenty volunteers and 30 patients were studied with HRM during barium swallows with concurrent fluoroscopy. Simultaneous bolus domain pressure and esophagogastric junction (EGJ) obstruction pressure were plotted and flow permissive time was tallied during which the bolus domain pressure exceeded the EGJ obstruction pressure. Distal peristaltic integrity was assessed at incrementally increasing pressure isobaric contour thresholds from 15–40 mmHg. ROC analysis was performed to assess the sensitivity and specificity of cutoff values for flow permissive time and peristaltic amplitude for predicting incomplete clearance as verified fluoroscopically.RESULTS: Flow permissive time ≤2.5 s had a sensitivity of 86% and specificity of 92% for predicting incomplete clearance. In contrast, a 30-mmHg peristaltic amplitude had a sensitivity of only 48% and specificity of 88%. Incomplete clearance was variably attributable to functional EGJ obstruction, hiatus hernia, or impaired peristalsis.CONCLUSIONS: A detailed analysis of intraluminal pressure gradients in the distal esophagus and across the EGJ in the postdeglutitive period predicts esophageal bolus clearance with far greater accuracy than any threshold value of peristaltic amplitude.

Challenging the Limits of Esophageal Manometry

After steady improvement until about 1980, the technology behind esophageal manometry saw little change until recent years. A variety of sensor technologies existed including solid-state strain gauge transducers, circumferentially sensitive transducers, multilumen perfused catheters with external pressure transducers, and the Dentsleeve device. However, irrespective of transducer design, the basic format of manometric studies was of multiple line-tracings representing pressure change versus time at several discrete esophageal loci. Furthermore, of the sensor designs available, only the Dentsleeve device provided a validated method for assessing sphincter relaxation. However, the Dentsleeve accomplished this at the expense of pressure response rate and spatial resolution leading some experts to focus instead on these limitations. In brief, little standardization existed in methodology among centers and there was no agreement regarding optimal assembly design or study interpretation.

Measuring EGJ opening patterns using high resolution intraluminal impedance

Abstract  The aim of this study was to adapt impedance methodology to study esophagogastric junction (EGJ) sphincter opening and compare opening patterns of the EGJ during deglutitive LES relaxation (dLESR) and transient LES relaxation (tLESR). We studied eight healthy subjects with a novel 12‐lumen combined impedance/manometry catheter, the main element of which was a 6 cm sleeve sensor with six side hole sensors and six impedance rings spaced at 1 cm increments along its length. Subjects underwent an air infusion protocol after standard assessment and data tracings and isocontour plots were analysed to assess opening characteristics of the EGJ during dLESRs and tLESRs. Our results revealed that during dLESR the opening pattern was top to bottom, occurred in 0–2.7 s and in 29 of 35 (83%) cases the leading edge of the bolus was liquid. Opening during tLESR began between −7.8 and +8.6 s relative to the onset of nadir LES relaxation. The opening pattern during tLESR was bottom to top, occurred in 0–7.7 s, and in 22 of 29 (76%) the leading edge was liquid. These results support that impedance monitoring can be adapted to identify sphincter opening, to distinguish sphincter opening from sphincter relaxation, and to determine luminal contents during the opening period.