Comparison of two high-resolution manometry software systems in evaluating esophageal motor function

BACKGROUND

High-resolution manometry (HRM) utilizes software tools to diagnose esophageal motor disorders. Performance of these software metrics could be affected by averaging and by software characteristics of different manufacturers.

METHODS

High-resolution manometry studies on 86 patients referred for antireflux surgery (61.6 ± 1.4 year, 70% F) and 20 healthy controls (27.9 ± 0.7 year, 45% F) were first subject to standard analysis (Medtronic, Duluth, GA, USA). Coordinates for each of 10 test swallows were exported and averaged to generate a composite swallow. The swallows and averaged composites were imported as ASCII file format into Manoview (Medtronic) and Medical Measurement Systems database reporter (MMS, Dover, NH, USA), and analyses repeated. Comparisons were made between standard and composite swallow interpretations.

KEY RESULTS

Correlation between the two systems was high for mean distal contractile integral (DCI, r² ≥ 0.9) but lower for integrated relaxation pressure (IRP, r² = 0.7). Excluding achalasia, six patients with outflow obstruction (mean IRP 23.2 ± 2.1 with 10-swallow average) were identified by both systems. An additional nine patients (10.5%) were identified as outflow obstruction (15 mmHg threshold) with MMS 10-swallow and four with MMS composite swallow evaluation; only one was confirmed. Ineffective esophageal motility was diagnosed by 10-swallow evaluation in 19 (22.1%) with Manoview, and 20 (23.3%) with MMS. On Manoview composite, 17 had DCI <450 mmHg/cm/s, and on MMS composite, 21, (p ≥ 0.85 for each comparison) but these did not impact diagnostic conclusions.

CONCLUSIONS & INFERENCES

Comparison of 10 swallow and composite swallows demonstrate variability in software metrics between manometry systems. Our data support use of manufacturer specific software metrics on 10-swallow sequences.

Effects of viscosity and volume on the patterns of esophageal motility in healthy adults using high-resolution manometry

The purpose of this study was to determine the effects of age, sex, body mass index (BMI), viscosity, and volume on esophageal motility using high-resolution manometry (HRM). Manometric studies were performed on 60 asymptomatic volunteers (27 men and 33 women, age: 19-56 years) while in a supine position. Manometric protocol included 10 water swallows (5 cc), 10 jelly swallows (5 cc), and 1 water swallow (20 cc). Evaluation of HRM parameters including length of proximal pressure trough (PPT length), distal latency (DL), contractile front velocity (CFV), distal contractile integral (DCI), and 4-second integrated relaxation pressure (IRP) was performed using MATLAB. Significant differences were noted in median IRP between water 5 cc (median 7.2 mmHg [range 5.5-9.6]), jelly 5 cc (median 6.0 mmHg [range 3.8-8.0]), and water 20 cc {(Median 4.8 mmHg [range 3.3-7.4]), P < 0.01}. DL were significantly different between water 5 cc, jelly 5 cc, and water 20 cc (P < 0.01), and in terms of PPT, proportions of small (2 cm ≤ < 5 cm) and large (5 cm≤) break for jelly 5 cc were significantly higher than those for the water 5 cc swallow (P < 0.05). Furthermore, DCI increased with age for water 5 cc, and a significant negative correlation was noticed between proportions of small break and BMI for water 5 cc. Manometric measurements vary depending on age, BMI, viscosity, and volume. These findings need to be taken into account in the interpretation of manometry results.

Botulinum toxin reduces Dysphagia in patients with nonachalasia primary esophageal motility disorders

BACKGROUND & AIMS

Endoscopic injection of botulinum toxin (BTX) has shown benefits for patients with diffuse esophageal spasm (DES) and nutcracker esophagus (NE) in small uncontrolled trials. We investigated the effect of BTX on symptoms of patients with DES or NE and assessed manometry findings in a prospective, double-blind, randomized, controlled study.

METHODS

We assessed 22 patients with dysphagia-predominant, manometry-confirmed DES or NE (6 men; age, 63 ± 2 y) at a tertiary care medical center. Patients were given injections of BTX (8 × 12.5 U) or saline (8 × 0.5 mL) in 4 quadrants, at 2 and 7 cm above the esophagogastric junction. After 1 month, patients crossed over between groups and received endoscopic injections of BTX or saline. When the study began and 4 weeks after each injection, the patients were assessed by esophageal manometry and completed a symptom questionnaire (to determine solid and liquid dysphagia, chest pain, and regurgitation and heartburn; all scored 0-4). Responders were defined based on modified Vantrappen criteria for achalasia.

RESULTS

After BTX injections, patients had significant decreases in total symptom scores (sum of solid and liquid dysphagia and chest pain; from 7.6 ± 0.7 to 4.8 ± 0.8; P = .01); this decrease was not observed in patients who received saline injections. Moreover, BTX injection stabilized unintentional weight loss (weight gain of 0.3 ± 0.3 after BTX injection vs further weight loss of 1.6 ± 0.5 kg after saline injection; P = .01). Fifty percent of patients had a response 1 month after BTX injection, compared with 10% after saline injection (P = .04); 30% still had a response 1 year after BTX injection. BTX injection also caused a significant decrease in the mean esophagogastric junction pressure, compared with baseline (15.8 ± 1.7 vs 24.0 ± 2.8 mm Hg; P = .02).

CONCLUSIONS

In a prospective controlled study of patients with DES and NE, injections of BTX reduced symptoms and stabilized unintentional weight loss.

TRIAL REGISTRY

http://www.targid.eu, ML2669, ML6294.

Automated calculation of the distal contractile integral in esophageal pressure topography with a region-growing algorithm

BACKGROUND

The distal contractile integral (DCI) is an index of contractile vigor in high-resolution esophageal pressure topography (EPT) calculated as the product of amplitude, duration, and span of the distal esophageal contraction. The aim of this study was to develop an automated algorithm calculating DCI.

METHODS

The DCI was calculated conventionally using ManoView™ (Given Imaging, Los Angeles, CA, USA) software in EPT studies from 72 controls and 20 patients and compared to the calculation using a MATLAB™ (Version 7.9.0, R2009b; The MathWorks Inc., Natick, MA, USA) 'region-growing' algorithm. This algorithm first established the spatial limits of the distal contraction (the proximal pressure trough to either the distal pressure trough or to the superior margin of the lower esophageal sphincter at rest). Pixel-by-pixel horizontal line segments were then analyzed within this span starting at the pressure maximum and extending outward from that point. The limits of 'region-growing' were defined either by the spatial DCI limits or by encountering a pressure <20 mmHg. The DCI was then calculated as the total units of mmHg s cm greater than 20 mmHg within this domain.

KEY RESULTS

Excellent correlation existed between the two methods (r = 0.98, P < 0.001). The DCI values obtained with the conventional calculation were slightly but significantly greater than with the region-growing algorithm. Differences were attributed to the inclusion of vascular pressures in the conventional calculation or to differences in localization of the distal limit of the DCI.

CONCLUSIONS & INFERENCES

The proposed region-growing algorithm provides an automated method to calculate DCI that limits inclusion of vascular pressure artifacts and minimizes the need for user input in data analysis.

Phenotypes and clinical context of hypercontractility in high-resolution esophageal pressure topography (EPT)

OBJECTIVES

This study aimed to refine the criteria for esophageal hypercontractility in high-resolution esophageal pressure topography (EPT) and to examine the clinical context in which it occurs.

METHODS

A total of 72 control subjects were used to define the threshold for hypercontractility as a distal contractile integral (DCI) greater than observed in normals. In all, 2,000 consecutive EPT studies were reviewed to find patients exceeding this threshold. Concomitant EPT and clinical variables were explored.

RESULTS

The greatest DCI value observed in any swallow among the control subjects was 7,732 mm Hg-s-cm; the threshold for hypercontractility was established as a swallow with DCI >8,000 mm Hg-s-cm. A total of 44 patients were identified with a median maximal DCI of 11,077 mm Hg-s-cm, all with normal contractile propagation and normal distal contractile latency, thereby excluding achalasia and distal esophageal spasm. Hypercontractility was associated with multipeaked contractions in 82% of instances, leading to the name "Jackhammer Esophagus." Dysphagia was the dominant symptom, although subsets of patients had hypercontractility in the context of esophagogastric junction (EGJ) outflow obstruction, reflux disease, or as an apparent primary motility disorder.

CONCLUSIONS

We describe an extreme phenotype of hypercontractility characterized in EPT by the occurrence of at least a single contraction with DCI >8,000 mm Hg-s-cm, a value not encountered in control subjects. This phenomenon, branded "Jackhammer Esophagus," was usually accompanied by dysphagia and occurred both in association with other esophageal pathology (EGJ outflow obstruction, reflux disease) or as an isolated motility disturbance. Further studies are required to define the pathophysiology and treatment of this disorder.