Isobaric Contour Research Articles

Compartmentalized pressurization is a novel prognostic factor for hypercontractile esophagus.

Hypercontractile esophagus (HE) is a disorder of increased esophageal body contractile strength on high-resolution esophageal manometry (HREM). Compartmentalized pressurization (CP) is a pattern with an isobaric contour of >30 mmHg extending from the contractile front to the lower esophageal sphincter on HREM. The relevance of CP to HE has yet to be explored. A retrospective review was performed on 830 HREM studies of patients to identify HE. HE patients' CP status and symptoms by Eckardt score (ES) were reviewed. Diagnoses were made using Chicago Classification (CC) v4.0. Forty-seven patients (5.6%) were identified as having HE by CCv3, 30 (3.6%) of which had HE by CCv4. 11/30 HE patients had CP, and 19/30 did not. CP was associated with chronic opioid use (36.4% vs. 5.3% p = 0.047). Presenting ES was greater for HE patients with CP (7 vs. 4). Seven HE patients with CP and 11 without CP were managed medically. ES after medical therapy was higher in HE patients with CP compared to those without CP (9 vs. 0). No HE patients with CP responded to medical therapy. Kaplan-Meier analysis demonstrated significance of this association over time. 83% of all HE patients had all-cause symptom remission. HE patients with CP are associated with a higher presenting ES. HE patients with CP do not respond to medical therapy, while HE patients without CP frequently do respond. CP in HE may have prognostic value in determination of treatment strategy for patients with HE.

True peristaltic recovery is uncommon following treatment, particularly endoscopic dilation for achalasia cardia, though pseudo-recovery often occurs.

Relieving esophagogastric junction (EGJ) obstruction has been the focus of treatment for achalasia cardia. The recovery of peristalsis has been an elusive goal. Studies analyzing post-intervention peristaltic recovery have several limitations such as theuse of conventional manometry or lack of standard definitions of peristalsis. Accordingly, we undertook this study to analyze frequency and pattern of peristaltic recovery following treatment for achalasia cardia on high-resolution manometry (HRM) and standard Chicago definition of peristalsis. Pre and post-intervention HRM records of 71 treatment-naive patients diagnosed as achalasia cardia were retrospectively analyzed. Records with pre and post-intervention HRM on different systems (e.g. solid state and water perfusion) and those with inadequate information were excluded. All HRMs were interpreted as per Chicago classification version 3.0. After pneumatic dilation (PD) or laparoscopic Heller's myotomy (LHM), pseudorecovery of peristalsis was defined as any contraction at least 3cm in length along 20mmHg isobaric contour with a distal latency of less than 4.5seconds. True recovery and premature contractions were defined by standard Chicago classification v3.0 criteria. Change in diagnosis was observed in 38 of 71 (53.5%) patients after intervention. While pseudo-peristaltic recovery occurred in 11 of 71 (15.5%) patients, only three (4.2%) had a true recovery. Another nine (12.7%) patients showed new premature contractions. True peristaltic recovery is uncommon in achalasia cardia following intervention, particularly PD. Pseudo-peristaltic recovery is more common. Further research is warranted on this issue.

Diagnostic methods to measure spastic segment and guide tailored myotomy length in type 3 achalasia.

Myotomy length in type 3 achalasia is generally tailored based on segment of spasticity on high-resolution manometry (HRM). Potential of length of tertiary contractions on barium esophagram (BE) or length of thickened circular muscle on endoscopic ultrasound (EUS) to guide tailored myotomy is less understood. This study aimed to assess agreement between spastic segments lengths on HRM, BE, and EUS among patients with type 3 achalasia. This retrospective study included adults with type 3 achalasia on HRM between November 2019 and August 2022 who underwent evaluation with EUS and/or BE. Spastic segments were defined as HRM-distance between proximal borders of lower esophageal sphincter and high-pressure area (isobaric contour ≥70 mmHg); EUS-length of thickened circular muscle (≥1.2 mm) from proximal border of esophagogastric junction (EGJ) to the transition to a non-thickened circular muscle; BE-distance between EGJ to proximal border of tertiary contractions. Pairwise comparisons assessed for correlation (Pearson's) and intraclass correlation classification (ICC) agreement. Twenty-six patients were included: mean age 66.9 years (SD 13.8), 15 (57.7%) male. Spastic segments were positively correlated on HRM and BE with good agreement (ICC 0.751, [95% CI 0.51, 0.88]). Spastic segments were negatively correlated with poor agreement on HRM and EUS (ICC -0.04, [-0.45, 0.39]) as well as BE and EUS (ICC -0.03, [-0.47, 0.42]). Length of spastic segment was positively correlated on HRM and BE while negatively correlated when compared to EUS, supporting the common use of HRM and highlighting the uncertain role for EUS in tailoring myotomy length for type 3 achalasia.

Esophagogastric junction contractile integral (EGJ-CI) complements reflux disease severity and provides insight into the pathophysiology of reflux disease.

Esophagogastric junction contractile integral (EGJ-CI) has not come into routine use due to methodological discrepancies and its unclear clinical utility. We aimed to determine which method of calculating EGJ-CI was best at discriminating between common reflux disease states. High-resolution manometry (HRM) and pH-Impedance measurements were acquired for 100 patients; 25 Barrett's esophagus (>3 cm/acid exposure time (AET) > 6), 25 endoscopy-negative reflux disease (ENRD; AET >6), 25 borderline reflux (AET 4-6), 25 functional heartburn (FH; AET <4), constituting the developmental cohort. EGJ-CI was calculated at 20 mmHg, 2 mmHg, and 0 mmHg isobaric contour. Empirical associations, univariable, multivariable and ROC analyses were performed between EGJ-CI and manometric/pH-impedance metrics. A validation cohort (n = 25) was used to test the new EGJ-CI cutoff. Significant correlations with AET were observed when EGJ-CI was calculated with an isobaric threshold of 20 mmHg (p < 0.001). Significant differences in EGJ-CI were observed between patients with FH and Barrett's esophagus (p = 0.004) and with ENRD (p = 0.01); however, LES basal pressure was unable to differentiate between these disease states (p = 0.09, p = 0.25, respectively). ROC analysis on the developmental cohort found that EGJ-CI 21.2 mmHg.cm demonstrated sensitivity 72% and specificity 72% between patients with reflux (Barrett's esophagus/ENRD) and FH. In the validation cohort, 92.8% with a low EGJ-CI had good/moderate improvement in symptoms following therapy compared to 54.5% with raised EGJ-CI (p = 0.026). This study re-affirms EGJ-CI as a reliable discriminator between reflux disease (Barrett's esophagus/ENRD) and FH. In borderline reflux patients, patients with a lower EGJ-CI score (<21.2 mmHg) appear to respond better to anti-reflux therapies compared to those with a higher value.

Breaks in peristaltic integrity predict abnormal esophageal bolus clearance better than contraction vigor or residual pressure at the esophagogastric junction.

High-resolution impedance manometry (HRIM) evaluates esophageal peristalsis and bolus transit. We used esophageal impedance integral (EII), the ratio between bolus presence before and after an expected peristaltic wave, to evaluate predictors of bolus transit. From HRIM studies performed on 61 healthy volunteers (median age 27years, 48%F), standard metrics were extracted from each of 10 supine water swallows: distal contractile integral (DCI, mmHgcms), integrated relaxation pressure (IRP, mmHg), and breaks in peristaltic integrity (cm, using 20mmHg isobaric contour). Pressure and impedance coordinates for each swallow were exported into a dedicated, python-based program for EII calculation (EII ratio≥0.3=abnormal bolus clearance). Univariate and multivariate analyses were performed to assess predictors of abnormal bolus clearance. Of 591 swallows, 80.9% were intact, 10.5% were weak, and 8.6% failed. Visual analysis overestimated abnormal bolus clearance compared to EII ratio (p≤0.01). Bolus clearance was complete (median EII ratio 0.0, IQR 0-0.12) in 82.0% of intact swallows in contrast to 53.3% of weak swallows (EII ratio 0.29, IQR 0.0-0.57), and 19.6% of failed swallows (EII ratio 0.5, IQR 0.34-0.73, p<0.001). EII correlated best with break length (ρ=0.52, p<0.001), compared to IRP (ρ: -0.17) or DCI (ρ: -0.42). On ROC analysis, breaks predicted abnormal bolus transit better than DCI or IRP (AUC 0.79 vs. 0.25 vs. 0.44, p≤0.03 for each). On logistic regression, breaks remained independently predictive of abnormal bolus transit (p<0.001). Breaks in peristaltic integrity predict abnormal bolus clearance better than DCI or IRP in healthy asymptomatic subjects.

Chicago Classification update (V4.0): Technical review on diagnostic criteria for ineffective esophageal motility and absent contractility.

Esophageal hypomotility disorders manifest with abnormal esophageal body contraction vigor, breaks in peristaltic integrity, or failure of peristalsis in the context of normal lower esophageal sphincter relaxation on esophageal high-resolution manometry (HRM). The Chicago Classification version 4.0 recognizes two hypomotility disorders, ineffective esophageal motility (IEM) and absent contractility, while fragmented peristalsis has been incorporated into the IEM definition. Updated criteria for ineffective swallows consist of weak esophageal body contraction vigor measured using distal contractile integral (DCI, 100-450mmHg·cm·s), transition zone defects >5cm measured using a 20mmHg isobaric contour, or failure of peristalsis (DCI<100mmHg·cm·s). More than 70% ineffective swallows and/or ≥50% failed swallows are required for a conclusive diagnosis of IEM. When the diagnosis is inconclusive (50%-70% ineffective swallows), supplementary evidence from multiple rapid swallows (absence of contraction reserve), barium radiography (abnormal bolus clearance), or HRM with impedance (abnormal bolus clearance) could support a diagnosis of IEM. Absent contractility requires 100% failed peristalsis, consistent with previous versions of the classification. Consideration needs to be given for the possibility of achalasia in absent contractility with dysphagia despite normal IRP, and alternate complementary tests (including timed upright barium esophagram and functional lumen imaging probe) are recommended to confirm or refute the presence of achalasia. Future research to quantify esophageal bolus retention on stationary HRM with impedance and to understand contraction vigor thresholds that predict bolus clearance will provide further refinement to diagnostic criteria for esophageal hypomotility disorders in future iterations of the Chicago Classification.

Application of a novel straight leg raise test during high-resolution manometry can predict esophageal contractile reserve in patients with gastroesophageal reflux disease.

Increased intra-abdominal pressure from abdominal compression augments esophageal peristalsis during high-resolution manometry (HRM), and straight leg raise (SLR) while supine increases intra-abdominal pressure. We determined if water swallows performed during SLR can mimic contraction reserve seen with multiple rapid swallows (MRS). Consecutive patients evaluated for GERD symptoms completed validated GERD questionnaires, esophageal HRM, and upper endoscopy. Distal contractile integral (DCI) was analyzed during single water swallows (10×5mL), MRS (5×2mL), and during SLR (5x5mL). Peristaltic breaks were measured using software tools with a 20mmHg isobaric contour. Univariate correlational analyses were performed to compare esophageal motor patterns and DCI values during single water swallows, MRS, and SLR. Of 103 study patients (mean age: 46.7±12.3years, 56.3% female), 50 (48.5%) had ineffective esophageal motility (IEM). Contraction reserve was observed on MRS in 62% with IEM, and 35.8% with normal motility (p=0.008). DCI was significantly higher during SLR compared to mean single swallow DCI in both IEM and normal motility patients (p<0.001 for each comparison). In IEM patients, SLR significantly reduced swallows with peristaltic breaks (6.1±3.7 vs 3.6±3.6; p<0.001) and shortened the length of the largest break (4.8±3.4 vs 3.0±3.0cm; p<0.001). DCI response following MRS correlated with DCI with swallows during SLR, with a correlational coefficient (Pearson's r) of 0.70 (p<0.001). Swallowing against the resistance of increased intra-abdominal pressure from SLR improves esophageal body peristaltic performance and predicts esophageal body contraction reserve.

Effects of Posture and Swallow Volume on Esophageal Motility Morphology and Probability of Bolus Clearance: A Study Using High-Resolution Impedance Manometry.

The Chicago classification diagnostic criteria of esophageal motility disorders are based on 5-ml water swallows in the supine position and have not been analyzed for the correlation between the morphology and bolus transit in the upright position and larger volume swallow conditions. This study aimed to evaluate the effect of posture and swallow volume on peristaltic morphology and the probability of bolus clearance in patients with nonspecific esophageal disorder. A total of 139 patients (4,214 swallows) were included for high-resolution impedance manometry analysis in the right lateral recumbent and upright positions, as well as 5- and 10-ml liquid swallows. Intact peristalses were more frequent in the right lateral recumbent position than in the upright position. No difference was reported on failed peristalsis between both positions. Breaks were more frequent in the upright position. A 20 mmHg isobaric contour (compared with 30 mmHg) was associated with decreased bolus clearance. Bolus clearance probability with 10-ml swallows is greater than that with 5-ml swallows. There was no significant difference in the total bolus clearance comparing between the right lateral recumbent and upright positions. The right lateral recumbent position was associated with a higher intact peristalsis. The volume of swallow did not affect the integrality of esophageal peristalsis but did improve the bolus clearance.

Vascular pressure bands on high-resolution esophageal manometry with impedance studies.

Horizontal pressure bands on high-resolution esophageal manometry with impedance (HREMI) tracings are often seen and thought to be due to cardiovascular structures compressing the esophagus. The aim of this study was to determine the prevalence and location of vascular pressure bands on HREMI studies and correlate these pressure bands to bolus clearance. HREMI studies in supine and upright positions from patients and normal volunteers were reviewed. Pressure bands were defined as bands of horizontal pressure greater than the 20mmHg isobaric contour. Each swallow was reviewed with impedance to determine if bolus transit was impaired by the band. 38.6% of 251 patients and 36.4% of 11 normal controls had a pressure band present. There were a greater number of bands in supine versus upright position (patients: 130 vs. 25, P< 0.001 and controls: 6 vs. 1). Patients with pressure bands had similar demographics (age, gender, BMI) compared to those without. Average distal contractile integral of bands was greater in supine compared to upright (133 ± 201 vs. 60 ± 148mmHgcms, P< 0.05). Bands were commonly located clustered at 46 and 72% of esophageal length. Bolus transit was impaired by bands in 20.4% of supine and 14.0% of upright swallows. Vascular pressure bands can have a prominent appearance on HREMI studies, present in, being more prevalent and having greater pressure in the supine than the upright position. These vascular bands, when present, may impair esophageal transit.

386 Delayed Esophago-Gastric Junction Relaxation in Patients With Jackhammer Esophagus Suggest That the Hypercontractile Peristalsis May Be a Compensatory Mechanism

INTRODUCTION: Jackhammer esophagus (JE) is esophageal motility disorder characterized by hypercontractile peristalsis, diagnosed by high resolution manometry (HRM) showing increased contractile vigor distal contractile integral (DCI) &gt;8000 mmHg/s/cm. Hypothesis: hypercontractile peristalsis in JE may be a compensatory mechanism for impaired EGJ relaxation, which even with normal integrated relaxation pressure (IRP), may be expressed as delayed onset of relaxation. We compare time to onset of EGJ relaxation in JE patients with normal IRP, control patients presenting for evaluation of esophageal symptoms with normal HRM, and asymptomatic healthy volunteers. METHODS: We compared time to onset of EGJ relaxation in 44 patients (24 JE, 20 with normal HRM) and 21 asymptomatic healthy volunteers who underwent HRM. Demographic characteristics and validated esophageal questionnaires (GERDQ, BEDQ, Eckardt) collected in all subjects. HRM performed by administering ten 5-ml liquid swallows, Chicago Classification v3.0 used to diagnose JE and normal esophageal motility. Time to onset of EGJ relaxation after swallow initiation was measured in seconds, from time of upper esophageal sphincter opening to EGJ opening. EGJ opening was determined at an isobaric contour of 23 mmHg, based on analysis in the healthy volunteers showing persistent EGJ effacement at this value in 100% of the volunteers. Median times to onset of relaxation for the study groups were compared by Wilcoxon rank sum test. RESULTS: Demographics, questionnaire scores, and HRM metrics in Table 1; patients were older and had higher scores compared to healthy volunteers; HRM metrics were different among the study groups with the exception of DL. Median times to onset of relaxation after swallow initiation shown in Figure 1. There was no difference in median time to onset of relaxation for volunteers compared to patient controls with normal HRM 0.20 s vs 0.90 s, P = 0.149. Median time to onset of relaxation was significantly longer in JE patients compared to volunteers and patient controls 3.30s vs 0.20 s vs 0.90 s, P = 0.001. CONCLUSION: Patients with JE and normal EGJ relaxation by IRP have significantly delayed onset of EGJ relaxation compared to healthy subjects and control patients with normal HRM. Hypercontractile peristalsis in these JE patients could be a compensatory mechanism to overcome outflow obstruction manifested as delayed EGJ relaxation. Therefore, if our findings are confirmed, therapies to address impaired EGJ relaxation could be considered.

How to Effectively Use High-Resolution Esophageal Manometry

How to Effectively Use High-Resolution Esophageal Manometry

Loss of Peristaltic Reserve, Determined by Multiple Rapid Swallows, Is the Most Frequent Esophageal Motility Abnormality in Patients With Systemic Sclerosis.

We assessed peristaltic reserve using multiple rapid swallows (MRS) during esophageal high-resolution manometry (HRM) of 111 patients with systemic sclerosis (89 women; ages, 42-64 y). We performed a retrospective analysis of HRM studies that included MRS in patients with systemic sclerosis, performed at 2 tertiary referral centers, and compared data with those from 18 healthy volunteers (controls). HRM findings were analyzed according to the Chicago Classification to provide an esophageal motility diagnosis. Response to MRS was evaluated for the presence of contraction and for augmentation, defined as the distal contractile integral after MRS greater than the median distal contractile integral of 10 supine swallows. Esophageal motility diagnoses included 41% with absent contractility, 31% with normal motility, 23% with ineffective esophageal motility, and 5% that met the criteria for other esophageal motility disorders. Contraction (37%) and peristaltic augmentation (18%) after MRS were observed less frequently in patients with systemic sclerosis than in controls (83% and 100%, respectively). Impaired peristaltic reserve, as assessed with MRS during HRM, is therefore the most common esophageal motility finding among patients with systemic sclerosis.

Oropharyngeal acid reflux and motility abnormalities of the proximal esophagus.

AIMTo investigate the relationship between pathological oropharyngeal (OP) acid exposure and esophageal motility in patients with extra-esophageal syndromes.METHODSIn this prospective study we enrolled consecutive outpatients with extra-esophageal symptoms suspected to be related to gastroesophageal reflux disease (GERD). We enrolled only patients with a reflux symptom index (RSI) score-higher than 13 and with previous lung, allergy and ear, nose and throat evaluations excluding other specific diagnoses. All patients underwent 24-h OP pH-metry with the Dx probe and esophageal high-resolution manometry (HRM). Patients were divided into two groups on the basis of a normal or pathological pH-metric finding (Ryan Score) and all manometric characteristics of the two groups were compared.RESULTSWe examined 135 patients with chronic extra-esophageal syndromes. Fifty-one were considered eligible for the study. Of these, 42 decided to participate in the protocol. Patients were divided into two groups on the basis of normal or pathological OP acid exposure. All the HRM parameters were compared for the two groups. Significant differences were found in the median upper esophageal sphincter resting pressure (median 71 mmHg vs 126 mmHg, P = 0.004) and the median proximal contractile integral (median 215.5 cm•mmHg•s vs 313.5 cm•mmHg•s, P = 0.039), both being lower in the group with pathological OP acid exposure, and the number of contractions with small or large breaks, which were more frequent in the same group. This group also had a larger number of peristaltic contractions with breaks in the 20 mmHg isobaric contour (38.7% vs 15.38%, P < 0.0001).CONCLUSIONIn patients with suspected GERD-related extra-esophageal syndromes pathological OP acid exposure was associated with weaker proximal esophageal motility.

The Chicago Classification of esophageal motility disorders, v3.0.

The Chicago Classification (CC) of esophageal motility disorders, utilizing an algorithmic scheme to analyze clinical high-resolution manometry (HRM) studies, has gained acceptance worldwide. This 2014 update, CC v3.0, developed by the International HRM Working Group, incorporated the extensive clinical experience and interval publications since the prior (2011) version. Chicago Classification v3.0 utilizes a hierarchical approach, sequentially prioritizing: (i) disorders of esophagogastric junction (EGJ) outflow (achalasia subtypes I-III and EGJ outflow obstruction), (ii) major disorders of peristalsis (absent contractility, distal esophageal spasm, hypercontractile esophagus), and (iii) minor disorders of peristalsis characterized by impaired bolus transit. EGJ morphology, characterized by the degree of overlap between the lower esophageal sphincter and the crural diaphragm and baseline EGJ contractility are also part of CC v3.0. Compared to the previous CC version, the key metrics of interpretation, the integrated relaxation pressure (IRP), the distal contractile integral (DCI), and the distal latency (DL) remain unchanged, albeit with much more emphasis on DCI for defining both hypo- and hypercontractility. New in CC v3.0 are: (i) the evaluation of the EGJ at rest defined in terms of morphology and contractility, (ii) 'fragmented' contractions (large breaks in the 20-mmHg isobaric contour), (iii) ineffective esophageal motility (IEM), and (iv) several minor adjustments in nomenclature and defining criteria. Absent in CC v3.0 are contractile front velocity and small breaks in the 20-mmHg isobaric contour as defining characteristics. Chicago Classification v3.0 is an updated analysis scheme for clinical esophageal HRM recordings developed by the International HRM Working Group.

High-resolution Impedance Manometry Criteria in the Sitting Position Indicative of Incomplete Bolus Clearance.

Background/AimsWe used high-resolution impedance manometry (HRIM) to determine the length of breaks on the isobaric contour which would predict incomplete bolus clearance in patients in the sitting position.MethodsIn total, 651 swallows in 71 patients with esophageal symptoms were studied using a solid-state HRIM system in the sitting position. Each swallow was classified as complete or incomplete bolus clearance by impedance criteria and peristaltic integrity was evaluated using 20- and 30-mmHg pressure topography isobaric contours. Correlations between the lengths of the breaks for 20- and 30-mmHg were analyzed.ResultsComplete bolus clearance was observed in 83.3% (542/651) of swallows. Breaks of 3 and 7 cm or less were associated with a bolus clearance of 96.8% on the 20-mmHg and 94.7% on the 30-mmHg isobaric contour, respectively (P < 0.001). The areas under the ROC curves for the 20 and 30 mmHg isobaric contours were 0.900 and 0.950, respectively. The sensitivity and specificity for complete bolus clearance were 75.6% and 89.3% for breaks 3 cm or less on the 20-mmHg isobaric contour and 87.9% and 78.7% for breaks 7 cm or less on the 30-mmHg contour (P < 0.001).ConclusionsBreaks of < 3 cm in the 20-mmHg isobaric contour or < 7 cm in the 30-mmHg isobaric contour were associated with com -plete bolus clearance. The threshold for breaks in the sitting position was greater than previous reports using the supine position and longer breaks predicted incomplete bolus clearance.

Tu1994 Increased Frequency of Transient Lower Esophageal Sphincter (LES) Relaxation in Cascade Stomach

Background: In the Chicago Classification (CC) peristaltic integrity is determined by the size of the largest break in the isobaric contour. However, bolus clearance might be affected by the occurrence of non-continuous breaks. The aim of the study was to assess the effect of peristaltic integrity on bolus clearance by using pressure-flow analysis. Methods: 22 solidstate high-resolution impedance manometry (HRIM) tracings of 10 liquid swallows of healthy asymptomatic adults (6M; mean age 36.1 SD 11.7 years) were retrospectively analysed using MMS analysis software (version 9.1). Measures of peristaltic integrity (largest break and total break size in cm of the 20mmHg isobar) were derived. Pressure-flow analysis was performed using purpose designed MATLAB-based software (AIMplot, T. Omari) which derived peak pressure (PeakP), intra-bolus pressure (IBP), bolus flow relative to peak pressure (PNadImp) and its timing to peak pressure (TNadImp-PeakP). In addition the pressure-flow index (PFI), a composite measure of bolus pressurisation relative to flow and the impedance ratio (IR) a measure of the extent of bolus clearance failure were calculated. Results: Out of 220 swallows, 214 were suitable for analysis. A strong correlation between total break size and the largest break in the isobaric contour was found (r=0.846,p=0.000). There was a trend towards larger break size and higher IR, with a stronger correlation for the largest break (table 1). Both largest break and total break size correlated with lower PeakP, lower PNadImp, lower IBP and longer TNadImp-PeakP. However, no correlation was found between larger break size and PFI. Conclusion: Largest break and total break size seem to characterize peristaltic integrity equally. Larger break size is associated with lower peristaltic pressurization and impaired bolus movement. There seems to be little quantifiable difference between the largest break and total breaksize in relation to bolus pressurization. Esophageal break size and AIM-derived pressure-flow metrics

Tu1993 High-Resolution Impedance Manometry: Effect of Peristaltic Integrity on Esophageal Pressurization

Background: In the Chicago Classification (CC) peristaltic integrity is determined by the size of the largest break in the isobaric contour. However, bolus clearance might be affected by the occurrence of non-continuous breaks. The aim of the study was to assess the effect of peristaltic integrity on bolus clearance by using pressure-flow analysis. Methods: 22 solidstate high-resolution impedance manometry (HRIM) tracings of 10 liquid swallows of healthy asymptomatic adults (6M; mean age 36.1 SD 11.7 years) were retrospectively analysed using MMS analysis software (version 9.1). Measures of peristaltic integrity (largest break and total break size in cm of the 20mmHg isobar) were derived. Pressure-flow analysis was performed using purpose designed MATLAB-based software (AIMplot, T. Omari) which derived peak pressure (PeakP), intra-bolus pressure (IBP), bolus flow relative to peak pressure (PNadImp) and its timing to peak pressure (TNadImp-PeakP). In addition the pressure-flow index (PFI), a composite measure of bolus pressurisation relative to flow and the impedance ratio (IR) a measure of the extent of bolus clearance failure were calculated. Results: Out of 220 swallows, 214 were suitable for analysis. A strong correlation between total break size and the largest break in the isobaric contour was found (r=0.846,p=0.000). There was a trend towards larger break size and higher IR, with a stronger correlation for the largest break (table 1). Both largest break and total break size correlated with lower PeakP, lower PNadImp, lower IBP and longer TNadImp-PeakP. However, no correlation was found between larger break size and PFI. Conclusion: Largest break and total break size seem to characterize peristaltic integrity equally. Larger break size is associated with lower peristaltic pressurization and impaired bolus movement. There seems to be little quantifiable difference between the largest break and total breaksize in relation to bolus pressurization. Esophageal break size and AIM-derived pressure-flow metrics

Sa1973 Diagnostic and Therapeutic Utility of SPYGLASS Peroral Cholangioscopy in Intraductal Pancreaticobiliary Disease: A Single-Center, Retrospective, Cohort Study

Example of esophageal impedance topography (EIT) plot showing the method for deriving EIT parameters Z1, Z2 and the Z2/Z1 ratio from a HRIM study. The pressure contours at 20 mmHg intervals (black solid lines) are overlaid with the enhanced impedance data (purple colorization) with the same resolution as pressure data in both time and spatial domain after interpolation. A region of interest (ROI, red dashed rectangle) is selected and the swallow event is divided into two sections by the contractile wave defined by the pressure isobaric contour. The impedance clearance contour (white curve) defines an impedance value of 50% drop from the mean baseline impedance to the mean nadir impedance and these white contours are superimposed on the EIT plot within the ROI for calculation of EIT parameters including bolus area in zone 1 (Z1), bolus area in zone 2 (Z2), and a ratio of Z2/ Z1, calculated to define the percentage of bolus that is retained in the esophagus after the swallow.

Sa1972 Bolus Flow Time Calculated From High-Resolution Impedance and Manometry (HRIM) Data Correlates With Timed Barium Esophagram Measures

Example of esophageal impedance topography (EIT) plot showing the method for deriving EIT parameters Z1, Z2 and the Z2/Z1 ratio from a HRIM study. The pressure contours at 20 mmHg intervals (black solid lines) are overlaid with the enhanced impedance data (purple colorization) with the same resolution as pressure data in both time and spatial domain after interpolation. A region of interest (ROI, red dashed rectangle) is selected and the swallow event is divided into two sections by the contractile wave defined by the pressure isobaric contour. The impedance clearance contour (white curve) defines an impedance value of 50% drop from the mean baseline impedance to the mean nadir impedance and these white contours are superimposed on the EIT plot within the ROI for calculation of EIT parameters including bolus area in zone 1 (Z1), bolus area in zone 2 (Z2), and a ratio of Z2/ Z1, calculated to define the percentage of bolus that is retained in the esophagus after the swallow.

A New Approach Is Needed to Analyze the Upper Esophageal Sphincter Because Currently Incorporated High-resolution Manometry Analysis Software Package Is Not Perfect.

TO THE EDITOR: I read with interest the review article by Wang et al1 regarding “High-resolution manometry (HRM) analysis of upper esophageal sphincter (UES) not addressed by the ‘Chicago classification’” disorders of the UES may include pharyngeal dysphagia and other cervical symptoms such as globus. Currently automated analysis of HRM provides the details of information such as mean basal UES pressure, mean residual UES pressure, UES relaxation time-to-nadir, UES relaxation duration, UES recovery time, and peak pharyngeal pressure. We have been evaluating whether HRM plays some roles in the assessment of the disorders of the UES with special interest for 4 years.2–4 To our experience, the information obtained by the software analysis often is not perfect as well as occasionally being wrong. Figure 1A shows erroneous locations of pharyngeal/UES wave markers, which are occurring despite of adequate setting thermal compensation and adjusting the spatial markers. Therefore it should be noted that it is very important to adjust the locations of the pharyngeal/UES wave markers correctly before the assessment of oropharyngeal dysphagia or globus. This problem frequently occurs in the setting of incomplete UES relaxation (Fig. 1B) and then gives misinformation regarding the duration of UES relaxation. However, it is very hard to correctly adjust UES wave markers under these circumstances. Given that, another new approach for quantitative assessment of UES relaxation should be considered. When we evaluate esophagogastric junction (EGJ) relaxation in the HRM examination, 4-second integrated relaxation pressure (IRP) is one of the best measures of EGJ relaxation, compared to nadir pressure and 3-second IRP.5 The opening time of UES is a lot shorter than that of EGJ. This suggests that IRP concept may be inappropriate in the assessment of UES relaxation. In HRM analysis, isobaric contours of 20 mmHg and 30 mmHg are currently used to assess distal contractile integral and distal segment contraction, respectively.5 These isobaric contours might be helpful for a more robust localization of these wave markers and then provide additional new concept regarding a measure of UES relaxation. To our experience, duration of UES relaxation on automated analysis seems to correlate well with the shortest horizontal distance from ending contour of pre-swallow UES peak to starting contour of post-swallow UES peak with 20 mmHg isobaric contour applied in this analysis (Fig. 2). This issue, however, should be further validated by larger study. In conclusion, we believe that the new approach should be introduced for better evaluation of disorders of the UES. Figure 1. Wrong location of pharyngeal/upper esophageal sphincter wave markers is noted. (A) Starting and ending points of UES relaxation wave makers are improperly located. (B) Starting, center and ending points of UES relaxation wave markers in third swallow ... Figure 2. Comparison of duration of the upper esophageal sphincter relaxation between automated analysis and new approach (using 20 mmHg isobaric contours).