Fifteen-year symptomatic outcome of patients with nonactionable motor findings on high-resolution manometry

BACKGROUND

High-resolution manometry (HRM) is performed for evaluation of esophageal symptoms, but patient outcome is unclear when no actionable motor disorder is identified. We evaluated long-term symptomatic outcome of patients with nonactionable HRM findings.

METHODS

Patients who underwent (HRM) studies in 2006-2008 were tracked. Patients with achalasia spectrum disorders, foregut surgery before or after HRM, and incomplete symptom documentation were excluded. Symptom questionnaires assessing dominant symptom intensity (DSI, product of symptom severity and frequency recorded on 5-point Likert scales) and global symptom severity (GSS, from 10 cm visual analog scale) were repeated. Change in symptom burden was compared against HRM motor findings using Chicago Classification 4.0 (CCv4.0), applied retroactively to 2006-2008 data.

KEY RESULTS

Overall, 134 patients (median age 68 years, 64.5% female) could be contacted. The majority (73.1%) had normal motility; others had ineffective esophageal motility (8.2%), esophagogastric junction outflow obstruction (13.4%), hypercontractile esophagus (3.0%), or absent contractility (2.2%), none managed invasively. Over 15 years of follow-up, DSI decreased from 8.0 (4.0-16.0) to 1.0 (0.0-6.0) (p < 0.001) and GSS improved from 5.5 (3.3-7.7) to 2.0 (0.0-4.0) (p < 0.001); improvement was consistent across CCv4.0 diagnoses and subgroups. The majority (82.8%) reported improvement over time, and antisecretory medication was the most effective intervention (83.0% improvement). There was no difference in medication efficacy (p = 0.75) or improvement in symptoms (p = 0.20) based on CCv4 diagnosis.

CONCLUSIONS AND INFERENCES

Esophageal symptoms improve with conservative symptomatic management over long-term follow-up when no conclusive obstructive motor disorders or achalasia spectrum disorders are found on HRM.

Artificial Intelligence Tools for Improving Manometric Diagnosis of Esophageal Dysmotility

PURPOSE OF REVIEW

Artificial intelligence (AI) is a broad term that pertains to a computer's ability to mimic and sometimes surpass human intelligence in interpretation of large datasets. The adoption of AI in gastrointestinal motility has been slower compared to other areas such as polyp detection and interpretation of histopathology.

RECENT FINDINGS

Within esophageal physiologic testing, AI can automate interpretation of image-based tests, especially high resolution manometry (HRM) and functional luminal imaging probe (FLIP) studies. Basic tasks such as identification of landmarks, determining adequacy of the HRM study and identification from achalasia from non-achalasia patterns are achieved with good accuracy. However, existing AI systems compare AI interpretation to expert analysis rather than to clinical outcome from management based on AI diagnosis. The use of AI methods is much less advanced within the field of ambulatory reflux monitoring, where challenges exist in assimilation of data from multiple impedance and pH channels. There remains potential for replication of the AI successes within esophageal physiologic testing to HRM of the anorectum, and to innovative and novel methods of evaluating gastric electrical activity and motor function. The use of AI has tremendous potential to improve detection of dysmotility within the esophagus using esophageal physiologic testing, as well as in other regions of the gastrointestinal tract. Eventually, integration of patient presentation, demographics and alternate test results to individual motility test interpretation will improve diagnostic precision and prognostication using AI tools.

Saliva Production and Esophageal Motility Influence Esophageal Acid Clearance Related to Post-reflux Swallow-Induced Peristaltic Wave

BACKGROUND

The post-reflux swallow-induced peristaltic wave (PSPW) brings salivary bicarbonate to neutralize residual distal esophageal mucosal acidification.

AIMS

To determine if reduced saliva production and esophageal body hypomotility would compromise PSPW-induced pH recovery in the distal esophagus.

METHODS

In this multicenter retrospective cross-sectional study, patients with confirmed Sjogren's syndrome and scleroderma/mixed connective tissue disease (MCTD) who underwent high resolution manometry (HRM) and ambulatory pH-impedance monitoring off antisecretory therapy were retrospectively identified. Patients without these disorders undergoing HRM and pH-impedance monitoring for GERD symptoms were identified from the same time-period. Acid exposure time, numbers of reflux episodes and PSPW, pH recovery with PSPW, and HRM metrics were extracted. Univariate comparisons and multivariable analysis were performed to determine predictors of pH recovery with PSPW.

RESULTS

Among Sjogren's syndrome (n = 34), scleroderma/MCTD (n = 14), and comparison patients with reflux symptoms (n = 96), the scleroderma/MCTD group had significantly higher AET, higher prevalence of hypomotility, lower detected reflux episodes, and very low numbers of PSPW (p ≤ 0.004 compared to other groups). There was no difference in pH-impedance metrics between Sjogren's syndrome, and comparison patients (p ≥ 0.481). Proportions with complete pH recovery with PSPW was lower in Sjogren's patients compared to comparison reflux patients (p = 0.009), predominantly in subsets with hypomotility (p < 0.001). On multivariable analysis, diagnosis of Sjogren's syndrome, scleroderma/MCTD or neither (p = 0.014) and esophageal hypomotility (p = 0.024) independently predicted lack of complete pH recovery with PSPW, while higher total reflux episodes trended (p = 0.051).

CONCLUSIONS

Saliva production and motor function are both important in PSPW related pH recovery.

Identification of Achalasia Within Absent Contractility Phenotypes on High-Resolution Manometry: Prevalence, Predictive Factors, and Treatment Outcome

INTRODUCTION

Absent contractility on high-resolution manometry (HRM) defines severe hypomotility but needs distinction from achalasia. We retrospectively identified achalasia within absent contractility using HRM provocative maneuvers, barium esophagography, and functional lumen imaging probe (FLIP).

METHODS

Adult patients with absent contractility on HRM during the 4-year study period were eligible for inclusion. Inadequate studies, achalasia after therapy, or prior foregut surgery were exclusions. Upright integrated relaxation pressure (IRP) >12 mm Hg, panesophageal pressurization, and/or elevated IRP on multiple rapid swallows and rapid drink challenge (RDC) were considered abnormal. Esophageal barium retention and abnormal esophagogastric junction distensibility index (<2.0 mm 2 /mm Hg) on FLIP defined achalasia. Clinical, endoscopic, and motor characteristics of patients with achalasia were compared with absent contractility without obstruction.

RESULTS

Of 164 patients, 20 (12.2%) had achalasia (17.9% of 112 patients with adjunctive testing), while 92 did not, and 52 did not undergo adjunctive tests. Achalasia was diagnosed regardless of IRP value, but the median supine IRP was higher (odds ratio 1.196, 95% confidence interval 1.041-1.375, P = 0.012). Patients with achalasia were more likely to present with dysphagia (80.0% vs 35.9%, P < 0.001), with obstructive features on HRM maneuvers (83.3% vs 48.9%, P = 0.039), but lower likelihood of GERD evidence (20.0% vs 47.3%, P = 0.027) or large hiatus hernia (15.0% vs 43.8%, P = 0.002). On multivariable analysis, dysphagia presentation ( P = 0.006) and pressurization on RDC ( P = 0.027) predicted achalasia, while reflux and presurgical evaluations and lack of RDC obstruction predicted absent contractility without obstruction.

DISCUSSION

Despite HRM diagnosis of absent contractility, achalasia is identified in more than 1 in 10 patients regardless of IRP value.

Reflux Symptoms Increase Following Sleeve Gastrectomy Despite Triage of Symptomatic Patients to Roux-en-Y Gastric Bypass

BACKGROUND AND AIMS

Bariatric surgical options in obese patients include sleeve gastrectomy (SG) and roux-en-Y gastric bypass (RYGB), which may not be equivalent in risk of postoperative reflux symptoms. We evaluated risk and predictive factors for postbariatric surgery reflux symptoms.

METHODS

Patients with obesity evaluated for bariatric surgery over a 15-month period were prospectively followed with validated symptom questionnaires (GERDQ, dominant symptom index: product of symptom frequency and intensity from 5-point Likert scores) administered before and after SG and RYGB. Esophageal testing included high-resolution manometry in all patients, and ambulatory reflux monitoring off therapy in those with abnormal GERDQ or prior reflux history. Univariate comparisons and multivariable analysis were performed to determine if preoperative factors predicted postoperative reflux symptoms.

RESULTS

Sixty-four patients (median age 49.0 years, 84% female, median BMI 46.5 kg/m 2 ) fulfilled inclusion criteria and underwent follow-up assessment 4.4 years after bariatric surgery. Baseline GERDQ and dominant symptom index for heartburn were significantly higher in RYGB patients ( P ≤0.04). Despite this, median GERDQ increased by 2 (0.0 to 4.8) following SG and decreased by 0.5 (-1.0 to 5.0) following RYGB ( P =0.02). GERDQ became abnormal in 43.8% after SG and 18.8% after RYGB ( P =0.058); abnormal GERDQ improved in 12.5% and 37.5%, respectively ( P =0.041). In a model that included age, gender, BMI, acid exposure time, and type of surgery, multivariable analysis identified SG as an independent predictor of postoperative heartburn (odds ratio 16.61, P =0.024).

CONCLUSIONS

Despite preferential RYGB when preoperative GERD was identified, SG independently predicted worsening heartburn symptoms after bariatric surgery.

Proximal Gastric Pressurization After Sleeve Gastrectomy Associates With Gastroesophageal Reflux

INTRODUCTION

Sleeve gastrectomy (SG) results in persistent or de novo reflux more often than Roux-en-Y gastric bypass (RYGB). We investigated pressurization patterns in the proximal stomach on high-resolution manometry (HRM) to determine associations with reflux after SG.

METHODS

Patients undergoing HRM and ambulatory pH-impedance monitoring after SG and RYGB over a 2-year period (2019-2020) were included. For each included patient, 2 symptomatic control patients with HRM and pH-impedance monitoring for reflux symptoms were identified within the same time frame; 15 asymptomatic healthy controls with HRM studies were also studied. Concurrent myotomy and preoperative diagnosis of obstructive motor disorders were exclusions. Conventional HRM metrics, esophagogastric junction (EGJ) pressures, contractile integral (EGJ-CI), acid exposure time (AET), and reflux episode numbers were extracted. Intragastric pressure was sampled at baseline, during swallows, and with straight leg raise maneuver, and compared with intraesophageal pressure and reflux burden.

RESULTS

Patient cohorts included 36 SG patients, 23 RYGB patients, 113 symptomatic controls, and 15 asymptomatic controls. While both SG and RYGB patients pressurized the stomach during swallows and straight leg raise, SG patients had higher AET (median 6.0% vs 0.2%), reflux episode numbers (median 63.0 vs 37.5), and baseline intragastric pressure (median 17.3 mm Hg vs 13.1 mm Hg) ( P < 0.001). SG patients also had lower trans-EGJ pressure gradients when reflux episodes were >80 or AET was >6.0% ( P = 0.018 and 0.08, respectively, compared with no pathologic reflux). On multivariable analysis, SG status and low EGJ-CI independently associated with AET and reflux episode numbers ( P ≤ 0.04).

DISCUSSION

Impaired EGJ barrier function and proximal gastric pressurization after SG are associated with gastroesophageal reflux, especially during strain maneuvers.

Application of Artificial Intelligence in Measuring Novel pH-Impedance Metrics for Optimal Diagnosis of GERD

Novel metrics extracted from pH-impedance monitoring can augment the diagnosis of gastroesophageal reflux disease (GERD). Artificial intelligence (AI) is being widely used to improve the diagnostic capabilities of various diseases. In this review, we update the current literature regarding applications of artificial intelligence in measuring novel pH-impedance metrics. AI demonstrates high performance in the measurement of impedance metrics, including numbers of reflux episodes and post-reflux swallow-induced peristaltic wave index and, furthermore, extracts baseline impedance from the entire pH-impedance study. AI is expected to play a reliable role in facilitating measuring novel impedance metrics in patients with GERD in the near future.

Chronic opioid users with dysphagia are indistinguishable from symptomatic nonusers on functional lumen imaging probe evaluation

BACKGROUND

Opioid-induced esophageal dysmotility (OIED) includes spastic esophageal motility disorders, increasingly recognized in the contemporary opioid epidemic. We assessed functional lumen imaging probe (FLIP) findings in diagnosing OIED.

METHODS

Symptomatic patients undergoing FLIP with no prior foregut surgery who completed validated questionnaires were identified and segregated into chronic opioid users and nonusers in this cohort study. Esophagogastric junction (EGJ) distensibility index (DI), EGJ diameter, and esophageal body contraction patterns were extracted. Symptom profiles were compared to FLIP findings between chronic opioid users and nonusers. Outcome was evaluated in a subset using the same validated questionnaires.

RESULTS

Over the 18-months study period, of 116 patients (median age 62 years, 70.7% female), 33 (28.4%) were chronic opioid users, with median morphine milligram equivalent of 30 mg. While presenting symptoms were similar, chronic opioid users reported higher perceptive symptoms (p = 0.008) and worse quality of life (p = 0.01) compared to nonusers. Median DI trended lower in chronic opioid users (p = 0.08), with more retrograde repetitive contractions (p < 0.001) and less absent contractility (p = 0.007), but final FLIP diagnoses were similar compared to nonusers. There was no correlation between opioid dose and FLIP metrics. In the subset with follow-up, perceptive symptoms trended higher in chronic opioid users (p = 0.08), but symptom improvement following therapy was similar in both groups.

CONCLUSIONS & INFERENCES

Symptomatic chronic opioid users have FLIP diagnoses that are similar to nonusers, despite higher perceptive symptoms and worse quality of life. Dominant symptoms improve both in chronic opioid users and nonusers following treatment directed by FLIP.

Effect of Increased Intra-abdominal Pressure on the Esophagogastric Junction: A Systematic Review

With the advent of high-resolution esophageal manometry, it is recognized that the antireflux barrier receives a contribution from both the lower esophageal sphincter (intrinsic sphincter) and the muscle of the crural diaphragm (extrinsic sphincter). Further, an increased intra-abdominal pressure is a major force responsible for an adaptive response of a competent sphincter or the disruption of the esophagogastric junction resulting in gastroesophageal reflux, especially in the presence of a hiatal hernia. This review describes how the pressure dynamics in the lower esophageal sphincter were discovered and measured over time and how this has influenced the development of antireflux surgery.

Improving the Diagnostic Yield of High-Resolution Esophageal Manometry for GERD: The "Straight Leg-Raise" International Study

BACKGROUND & AIMS

The straight leg raise (SLR) maneuver during high-resolution manometry (HRM) can assess esophagogastric junction (EGJ) barrier function by measuring changes in intraesophageal pressure (IEP) when intra-abdominal pressure is increased. We aimed to determine whether increased esophageal pressure during SLR predicts pathologic esophageal acid exposure time (AET).

METHODS

Adult patients with persistent gastroesophageal reflux disease (GERD) symptoms undergoing HRM and pH-impedance or wireless pH study off proton pump inhibitor were prospectively studied between July 2021 and March 2022. After the HRM Chicago 4.0 protocol, patients were requested to elevate 1 leg at 45º for 5 seconds while supine. The SLR maneuver was considered effective when intra-abdominal pressure increased by 50%. IEPs were recorded 5 cm above the lower esophageal sphincter at baseline and during SLR. GERD was defined as AET greater than 6%.

RESULTS

The SLR was effective in 295 patients (81%), 115 (39%) of whom had an AET greater than 6%. Hiatal hernia (EGJ type 2 or 3) was seen in 135 (46%) patients. Compared with patients with an AET less than 6%, peak IEP during SLR was significantly higher in the GERD group (29.7 vs 13.9 mm Hg; P < .001). Using receiver operating characteristic analysis, an increase of 11 mm Hg of peak IEP from baseline during SLR was the optimal cut-off value to predict an AET greater than 6% (area under the receiver operating characteristic curve, 0.84; sensitivity, 79%; and specificity, 85%), regardless of the presence of hiatal hernia. On multivariable analysis, an IEP pressure increase during the SLR maneuver, EGJ contractile integral, EGJ subtype 2, and EGJ subtype 3, were found to be significant predictors of AET greater than 6% CONCLUSIONS: The SLR maneuver can predict abnormal an AET, thereby increasing the diagnostic value of HRM when GERD is suspected.

CLINICALTRIALS

gov ID: NCT04813029.

Solid bolus swallows during high-resolution manometry complement multiple rapid swallows in predicting symptoms following antireflux surgery

BACKGROUND

Solid bolus swallows (SBS) assess esophageal peristalsis on high-resolution manometry (HRM). It remains unknown if increase in contraction vigor (contraction reserve) following SBS (SBS-CR) provides information similar to that observed following multiple rapid swallows (MRS-CR).

METHODS

Clinical and HRM data from adult patients (n = 96, age 58.2 years, 61.5% female) undergoing esophageal testing prior to anti-reflux surgery (ARS) were analyzed if both MRS and SBS were available, and compared to similar data from healthy asymptomatic volunteers (n = 18, age 27.5 years, 55.6% female). Patients reported esophageal symptoms before and after ARS using 5-point Likert scales evaluating symptom frequency and severity; scores for each patient were averaged to determine global symptoms. Distal contractile integral (DCI) from single swallows was compared to MRS DCI and SBS DCI; the ratio of single swallow DCI to MRS DCI or SBS DCI ≥1 determined the presence of contraction reserve.

KEY RESULTS

Multiple rapid swallows CR was concordant with SBS CR in 55.6% of healthy volunteers, 100% of absent contractility, 100% of ineffective esophageal motility (IEM) and 56.9% without IEM. Correlation between MRS DCI and SBS DCI was highest when IEM criteria were met (Spearman's rho 0.998). While neither MRS CR nor SBS CR presence differed by presenting symptoms or global symptom score at baseline, post-ARS global symptom burden was highest in the absence of both MRS CR and SBS CR, especially in patients with esophageal hypomotility using Chicago Classification version 4.0 criteria (p = 0.03).

CONCLUSIONS & INFERENCES

Multiple rapid swallows and SBS are complementary in predicting post-ARS symptom burden.

The clinical value of psycho-gastroenterological interventions for functional esophageal symptoms

BACKGROUND

Disorders of gut-brain interaction (DGBI) are associated with high symptom burden and poor quality of life. We evaluated the clinical value of multimodal therapy with psycho-gastroenterological interventions in patients with refractory functional symptoms.

METHODS

Of 80 DGBI patients managed over a 12-month period, 26 patients undergoing multimodal therapy (median age 60.0 years, 73.1%F) were compared to 54 patients (median age 56.0 years, 68.5%F) managed using conventional approaches. Psycho-gastroenterological multimodal therapy was individualized and included relaxation training (diaphragmatic breathing, passive muscle relaxation) and gut-direct hypnotherapy/guided imagery. All patients completed documentation of symptom frequency and severity using a 100 mm visual analog scale (VAS) and assessment of health-related quality of life (BEST score) before and following therapy. Data were analyzed to determine comparative change in symptom burden between the two cohorts.

KEY RESULTS

Baseline demographics and symptom burden were similar between the two treatment subgroups. While patients improved with both multimodal and conventional therapies, BEST score demonstrated greater improvement with multimodal therapy (p = 0.03). Physician perception of symptom burden at baseline and on follow-up did not correspond to self-reported questionnaire data. On multivariable analysis, multimodal therapy (OR 7.9, 95% CI 1.8-34.6, p = 0.006) and functional esophageal disorders (OR 17.6, 95% CI 2.6-121.1, p = 0.004) predicted >50% improvement in BEST score, while the presence of psychiatric disease was a negative predictor (OR 0.22, CI 0.05-0.94, p = 0.04).

CONCLUSIONS & INFERENCES

Psychological intervention using multimodal therapy provides clinical value to the management of functional esophageal symptoms among patients refractory to conventional therapy.

Current advances in the diagnosis and management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is very common and defined as troublesome symptoms owing to excessive acid reflux. The spectrum of GERD is broad, including not only erosive esophagitis and Barrett's esophagus but also nonerosive reflux disease (NERD), reflux hypersensitivity, and functional heartburn. Patients with reflux symptoms despite normal endoscopy remain common clinical presentation, can be heterogeneous overlapping with functional gastrointestinal disorders. Ambulatory esophageal pH monitoring with and without impedance helps the diagnosis of NERD. Metrics such as baseline impedance and postreflux swallow induced peristaltic wave enhance diagnostic accuracy in patients with inconclusive diagnoses. The major treatment of all manifestations of GERD is acid suppression with proton pump inhibitors, while other therapies, such as reflux-reducing agents and adjunctive medications, can be individualized where the response to traditional management is incomplete. GERD patients often need long-term treatment due to frequent relapses. Anti-reflux surgery can be effective too. Endoscopic therapies have some promising results, but long-term outcomes remain to be determined.

Emerging therapies in the management of Irritable Bowel Syndrome (IBS)

INTRODUCTION

Irritable bowel syndrome (IBS) is a common, symptom-based disorder of chronic abdominal pain and altered bowel habits. The pathogenesis of IBS is multifactorial, leading to the potential for the development of multiple, diverse treatment strategies. This mechanistic heterogeneity also leads to the realization that available therapies are only effective in a subset of IBS suffers. Current US Food and Drug Administration (FDA) approved therapies for IBS with diarrhea (IBS-D) and IBS with constipation (IBS-C) are reviewed. Limited symptom responses and side effect experiences lead to considerable patient dissatisfaction with currently available IBS treatments. Only a small percentage of IBS patients are on prescription therapies underscoring the potential market and need for additional therapeutic options.

AREAS COVERED

: Expanding on currently available therapies, the serotonergic and endogenous opioid receptor systems continue to be a focus of future IBS treatment development. Additional novel emerging therapies include the endogenous cannabinoid system, bile acid secretion and sequestration, and exploit our enhanced understanding of visceral sensory signaling and intestinal secretomotor function.

EXPERT OPINION

While challenges remain for the future development of IBS therapies, the diverse etiologies underlying the disorder present an opportunity for novel therapies. Hence, great potential is anticipated for future IBS treatment options.

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

BACKGROUND

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.

METHODS

From HRIM studies performed on 61 healthy volunteers (median age 27 years, 48%F), standard metrics were extracted from each of 10 supine water swallows: distal contractile integral (DCI, mmHg cm s), integrated relaxation pressure (IRP, mmHg), and breaks in peristaltic integrity (cm, using 20 mmHg 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.

KEY RESULTS

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).

CONCLUSIONS & INFERENCES

Breaks in peristaltic integrity predict abnormal bolus clearance better than DCI or IRP in healthy asymptomatic subjects.

Making Sense of Nonachalasia Esophageal Motor Disorders

Achalasia is the prototypical obstructive motor disorder diagnosed using HRM, but non-achalasia motor disorders are often identified in symptomatic patients. The clinical relevance of these disorders are assessed using ancillary HRM maneuvers (multiple rapid swallows, rapid drink challenge, solid swallows) that augment the standard supine HRM evaluation by challenging peristaltic function. Finding obstructive motor physiology in non-achalasia motor disorders may raise the option of invasive management akin to achalasia. Certain non-achalasia disorders, particularly hypermotility disorders, may manifest as epiphenomena seen with esophageal hypersensitivity. Symptomatic management is offered for superimposed reflux disease, psychological disorders, functional esophageal disorders, and behavioral disorders.

Value of pH Impedance Monitoring While on Twice-Daily Proton Pump Inhibitor Therapy to Identify Need for Escalation of Reflux Management

BACKGROUND AND AIMS

Acid exposure time (AET) and reflux episode thresholds from the Lyon Consensus may not apply for pH impedance studies performed while on proton pump inhibitor (PPI) therapy. We aimed to determine metrics from "on PPI" pH impedance studies predicting need for escalation of therapy.

METHODS

De-identified pH impedance studies performed while on twice-daily PPI (Diversatek, Boulder, CO) in healthy volunteers (n = 66, median age 37.5 years, 43.9% female), and patients with proven gastroesophageal reflux disease (GERD) (European heartburn-predominant cohort: n = 43, median age 57.0 years, 55.8% female; North American regurgitation-predominant cohort: n = 42, median age 41.6 years, 42.9% female) were analyzed. Median values and interquartile ranges for pH impedance metrics in healthy volunteers were compared with proven GERD patients with and without 50% symptom improvement on validated measures. Receiver operating characteristic (ROC) analyses identified optimal thresholds predicting symptom response.

RESULTS

Both conventional and novel reflux metrics were similar between PPI responders and nonresponders (P ≥ .1 for each) despite differences from healthy volunteers. Combinations of metrics associated with conclusively abnormal reflux burden (AET >4%, >80 reflux episodes) were seen in 32.6% and 40.5% of heartburn and regurgitation-predominant patients, respectively, 57.1% and 82.4% of whom reported nonresponse; and 85% with these metrics improved with invasive GERD management. On ROC analysis, AET threshold of 0.5% modestly predicted nonresponse (sensitivity, 0.62; specificity, 0.51; P = .22), and 40 reflux episodes had better performance characteristics (sensitivity, 0.80; specificity, 0.51; P = .002); 79% with these metrics improved with invasive GERD management.

CONCLUSION

Combinations of abnormal "on PPI" pH impedance metrics are associated with PPI nonresponse in proven GERD patients, and can be targeted for treatment escalation, including surgery, particularly in regurgitation-predominant GERD.

Biopsy forceps disruption paired with bougie dilation of esophageal strictures lengthens time to repeat intervention

Esophageal strictures commonly cause dysphagia and require treatment with endoscopic dilation using balloons or bougies. We aimed to determine whether biopsy forceps disruption of strictures at time of dilation increases time to repeat intervention or duration of intervention-free follow-up. We performed a retrospective analysis of 289 adults (age 61.0 ± 0.8 years, 66.4% female) who underwent dilation of an esophageal stricture at our tertiary care center between 2014 and 2016. Exclusions consisted of endoscopic intervention within the preceding 6 months, prior foregut neoplasia, achalasia, radiofrequency ablation, endoscopic mucosal resection, endoscopic submucosal dissection, or foregut surgery. Demographics, clinical presentation, dilation technique, and follow-up were abstracted from electronic medical records. We compared time to repeat dilation and duration of intervention-free follow-up between treatment subgroups. Balloon dilation was performed more often than bougie dilation (76.8 vs. 17.6%); biopsy forceps disruption was performed in 23.2%. Over a median follow-up of 52.9 months, 135 patients (46.7%) underwent repeat dilation. Age, body mass index, gender, and use of antisecretory medications did not influence need for repeat dilation (P = ns for each). Bougie dilation with biopsy forceps disruption prolonged time to repeat dilation in all patients (P ≤ 0.02), particularly in those with gastroesophageal reflux disease (P ≤ 0.03), compared with bougie dilation alone and balloon dilation with or without disruption. On Kaplan-Meier analysis, bougie dilation with biopsy forceps resulted in longer intervention-free follow-up compared with dilation alone (P = 0.03). We conclude that stricture disruption with biopsy forceps increases time to repeat intervention with bougie but not balloon dilation.

Esophagogastric junction morphology and contractile integral on high-resolution manometry in asymptomatic healthy volunteers: An international multicenter study

BACKGROUND

Esophagogastric junction contractile integral (EGJ-CI) and EGJ morphology are high-resolution manometry (HRM) metrics that assess EGJ barrier function. Normative data standardized across world regions and HRM manufacturers are limited.

METHODS

Our aim was to determine normative EGJ metrics in a large international cohort of healthy volunteers undergoing HRM (Medtronic, Laborie, and Diversatek software) acquired from 16 countries in four world regions. EGJ-CI was calculated by the same two investigators using a distal contractile integral-like measurement across the EGJ for three respiratory cycles and corrected for respiration (mm Hg cm), using manufacturer-specific software tools. EGJ morphology was designated according to Chicago Classification v3.0. Median EGJ-CI values were calculated across age, genders, HRM systems, and regions.

RESULTS

Of 484 studies (28.0 years, 56.2% F, 60.7% Medtronic studies, 26.0% Laborie, and 13.2% Diversatek), EGJ morphology was type 1 in 97.1%. Median EGJ-CI was similar between Medtronic (37.0 mm Hg cm, IQR 23.6-53.7 mm Hg cm) and Diversatek (34.9 mm Hg cm, IQR 22.1-56.1 mm Hg cm, P = 0.87), but was significantly higher using Laborie equipment (56.5 mm Hg cm, IQR 35.0-75.3 mm Hg cm, P < 0.001). 5^th percentile EGJ-CI values ranged from 6.9 to 12.1 mm Hg cm. EGJ-CI values were consistent across world regions, but different between manufacturers even within the same world region (P ≤ 0.001). Within Medtronic studies, EGJ-CI and basal LESP were similar in younger and older individuals (P ≥ 0.3) but higher in women (P < 0.001).

CONCLUSIONS

EGJ morphology is predominantly type 1 in healthy adults. EGJ-CI varies widely in health, with significant gender influence, but is consistent within each HRM system. Manufacturer-specific normative values should be utilized for clinical HRM interpretation.

Number of reflux episodes on pH-impedance monitoring associates with improved symptom outcome and treatment satisfaction in gastro-oesophageal reflux disease (GERD) patients with regurgitation

OBJECTIVE

Number of reflux episodes, an adjunctive metric on pH-impedance monitoring, is incompletely studied. We aimed to determine if number of reflux episodes associates with therapeutic outcome in regurgitation predominant gastro-oesophageal reflux disease (GERD).

DESIGN

We performed post hoc analysis of postintervention pH-impedance data from adult patients with moderate/severe regurgitation despite QD proton pump inhibitor (PPI), randomised to either two times a day PPI or magnetic sphincter augmentation (MSA) in 2:1 allocation. After 6 and 12 months, symptom response was defined by improvement in Foregut Symptom Questionnaire (FSQ) regurgitation score to none or minimal, ≥50% reduction in GERD health-related quality of life (HRQL) score and satisfaction with therapy. Univariate and multivariate analyses were performed to determine predictors of symptom improvement.

RESULTS

Of 152 randomised patients, 123 (age 46.9±1.2 year, 43% female) had complete data. Symptom and satisfaction scores significantly improved after MSA compared with two times a day PPI. Both acid exposure time (13.4%±0.7% to 1.3±0.2%, p<0.001) and reflux episodes (86±4 to 48±4, p<0.001) declined with therapy. Reduction to <40 reflux episodes was significantly more frequent in those with symptom response by FSQ regurgitation score, GERD HRQL score and satisfaction with therapy (p≤0.03 for each); <35 episodes performed better on receiver operating characteristic analysis. On multivariate analysis, improvement in regurgitation score remained independently predictive of satisfaction with therapy (p<0.001 for each). In patients crossing over to MSA, >80 episodes pretreatment predicted improvement.

CONCLUSIONS

Reduction of reflux episodes on pH-impedance to physiological levels associates with improved outcomes, while pathological levels predict improvement with MSA in regurgitation predominant GERD.

TRAIL REGISTRATION NUMBER

ClinicalTrials.gov: NCT02505945.

Postreflux swallow-induced peristaltic wave index from pH-impedance monitoring associates with esophageal body motility and esophageal acid burden

BACKGROUND

Postreflux swallow-induced peristaltic wave (PSPW) on pH-impedance monitoring and contraction vigor on high-resolution manometry (HRM) both assess esophageal peristaltic response. We aimed to evaluate relationships between PSPW and esophageal peristalsis on HRM in the context of reflux disease in this multicenter cohort study.

METHODS

pH-impedance and HRM studies performed on patients with persisting reflux symptoms were reviewed from 6 centers (5 in Europe and 1 in US). Total, upright and supine acid exposure time (AET) were evaluated from pH-impedance studies; PSPW index (PSPWI) and mean nocturnal baseline impedance (MNBI) were calculated using standard methodology. Esophageal body contraction vigor was analyzed using distal contractile integral (DCI), and DCI ratio > 1 between single swallows and multiple rapid swallows (MRS) defined presence of contraction reserve. Student's t test, ANOVA, and linear regression were utilized to investigate relationships between PSPW, contraction vigor, and contraction reserve.

KEY RESULTS

Of 296 patients (52.8 ± 0.8 yr, 63% F), median PSPWI was 0.475. Only 24.0% had intact DCI; the remainder had varying degrees of hypomotility. As hypomotility increased, PSPWI and MNBI decreased significantly, while total AET and reflux episodes had an inverse response (P ≤ .002 for each). MRS data were available in 167 (56.4%), 72.5% had contraction reserve. MRS cohorts with normal PSPWI had significantly lower reflux burden compared to low PSPWI, regardless of presence or absence of contraction reserve (P ≤ .001).

CONCLUSIONS AND INFERENCES

PSPWI correlates with esophageal hypomotility and reflux burden, and complements clinical reflux evaluation. Intact PSPW is more relevant to esophageal reflux clearance than contraction reserve.

Straight leg raise metrics on high-resolution manometry associate with esophageal reflux burden

BACKGROUND

Straight leg raise (SLR) is a provocative maneuver that assesses esophagogastric junction (EGJ) barrier function during high-resolution manometry (HRM). We evaluated the value of SLR in symptomatic reflux patients undergoing ambulatory reflux monitoring.

METHODS

Adult patients being evaluated for reflux symptoms with esophageal physiologic testing off antisecretory therapy over a 12 month period were studied. Demographics, clinical presentation, HRM studies, and reflux monitoring studies were analyzed. Intra-abdominal and intra-esophageal pressures were extracted at baseline and during SLR from HRM studies. Acid exposure time (AET) was derived from reflux monitoring studies, and EGJ morphology and tone from HRM studies. SLR pressure metrics predicting abnormal AET were evaluated.

KEY RESULTS

Of 122 patients, 70 (57.4%) had ≥50% peak intra-abdominal pressure increase during SLR (58.0 ± 1.4 years, 75.7% female). Peak intra-esophageal pressure gradient between baseline and SLR predicted pathologic AET when ≥100% (AUC 0.78, sensitivity 71%, specificity 75%, P < .001), seen in 60.7% with AET > 6%, but only 23.7% with AET < 4% (P = .01). Peak intra-esophageal pressure gradient ≥100% was most discriminative in identifying abnormal acid burden in type 1 EGJ morphology (P = .005) but trended toward significance in type 2 and type 3 morphology (P = .1). Normal and abnormal EGJ contractile integral did not associate with peak intra-esophageal pressure gradient either collectively or when subdivided by EGJ morphology (P ≥ .2).

CONCLUSIONS & INFERENCES

Analysis of intra-esophageal pressure gradients during SLR, a simple HRM maneuver, may augment evaluation of symptomatic GERD, and provide adjunctive evidence supporting GERD.

Patient Engagement with Interactive Text Message System Improves Successful Colonoscopy Rates in an Outpatient Endoscopy Center

INTRODUCTION

Text message-based interventions reduce colonoscopy no-show rates and improve bowel preparation scores. In this non-randomized study, we assessed whether an interactive text messaging system could improve colonoscopy outcomes.

METHODS

Colonoscopy pre-procedural instructions were programmed into a dedicated software platform created for this study. In the intervention arm, text messages were sent to veterans during a 4-week study period. Validated pre-procedural satisfaction questionnaires were completed by patients during standard protocol and intervention periods. Demographics and colonoscopy outcomes data were compared between the standard protocol and intervention arms, including procedure completion rate on scheduled date, Boston bowel preparation score (BPPS), adenoma detection rate, and satisfaction.

RESULTS

Of 241 patients, 128 were in the standard protocol arm and 113 in the intervention arm. Higher proportions of patients receiving text messages underwent colonoscopy on their scheduled date (69.9%) compared to the ones in the standard protocol (50.8%, p = 0.015). Patients with ≥3 interactions with the system had 80.6% likelihood of completing colonoscopy on the scheduled date compared to 56.9% with <3 interactions and 50.8% with standard protocol (p < 0.001). Frequency of interaction with the system was similar between older (>65 years) and younger patients (p = 1.0). Among older patients, colonoscopy was completed successfully in 84.2% when alert-based human interactions occurred compared to 65.6% in those without and 47.9% with standard protocol (p = 0.018). More than 90% indicated they would recommend the system to patients undergoing future colonoscopy.

CONCLUSION

An interactive text messaging system improves successful colonoscopy rates in a VA setting, with greatest impact in older patients.

Enhancing High-Resolution Esophageal Manometry: Use of Ancillary Techniques and Maneuvers

High-resolution manometry evaluates esophageal motor function using 10 supine water swallows. Superimposing impedance over high-resolution manometry pressure topography assesses the relationship between contraction and bolus propulsion and identifies inadequate clearance. Ancillary techniques and maneuvers augment the standard supine high-resolution manometry evaluation by challenging peristaltic function. Increasing bolus volume (rapid drink challenge) and altering bolus consistency (standardized test meal, solid swallows) enhance identification of esophageal outflow obstruction syndromes. Physiologic maneuvers (multiple rapid swallows, abdominal compression) address the ability of the esophageal smooth muscle to augment contraction vigor. Pharmacologic challenge is less commonly used clinically, and elucidates pathophysiology of esophageal motor disorders.

Higher Esophageal Symptom Burden in Obese Subjects Results From Increased Esophageal Acid Exposure and Not From Dysmotility

BACKGROUND & AIMS

Esophageal motor disorders (EMD) and pathologic reflux are often identified in obese individuals, but it is not clear how obesity contributes to these symptoms. We examined the relationships among symptom burden, EMD, acid exposure time (AET), symptom association probability, and body mass index (BMI).

METHODS

We performed a retrospective study of 1089 consecutive patients who underwent high-resolution manometry, of which 426 patients also underwent reflux monitoring off acid suppression, over a 2-year period at a tertiary referral center. Symptom burden was assessed by questionnaires to determine dominant symptom intensity (DSI; product of symptom severity, and frequency, on 5-point Likert scales) and global symptom severity (GSS; global esophageal symptoms on 10-cm visual analog scales) at the time of esophageal testing; BMIs were recorded. We compared proportions of patients with EMD and abnormal reflux burden among BMI categories and correlated them with symptom burden.

RESULTS

Four-hundred thirty-three patients (39.8%) met the criteria for EMD. Esophageal outflow obstruction was observed in higher proportions of patients with low BMIs (underweight, 25.9%; normal, 14.1%; overweight, 13.9%; and obese, 9.8%; P = .037), but EMDs were less frequent in obese patients (P = .047), despite higher symptom burden compared with non-obese patients (DSI, 10.5 ± 0.3 vs 9.7 ± 0.2; P = .03 and GSS, 6.5 ± 1 vs 5.9 ± 1; P = .01). Among the 426 patients who underwent reflux monitoring, the proportions with total AET (P = .02), and upright AET (P < .001) increased among BMI categories, supine AET trended strongly (P = .06), in combination with increasing DSI and GSS (P ≤ .001 for each comparison). BMI correlated with symptom burden, higher AET, and positive symptom association probability (P < .01 for each analysis).

CONCLUSIONS

Increased symptom burden in obese individuals correlates with esophageal acid burden but not with motor disorders.

Fragmented and failed swallows on esophageal high-resolution manometry associate with abnormal reflux burden better than weak swallows

BACKGROUND

Association between proportions of hypomotile swallows on esophageal high-resolution manometry (HRM) and esophageal reflux burden remains incompletely understood. We investigated relationships between hypomotility, acid exposure time (AET), and mean nocturnal baseline impedance (MNBI) on ambulatory reflux monitoring.

METHODS

Clinical data, HRM, and ambulatory pH-impedance studies (performed off acid suppression) from patients with persisting reflux symptoms were reviewed from five international centers. AET (abnormal > 6%) and MNBI (abnormal < 2292 ohms) were extracted from pH-impedance studies. Distal contractile integral (DCI) designated esophageal peristalsis into normal (DCI > 450 mmHg.cm.s), fragmented (DCI > 450 mmHg.cm.s with breaks > 5 cm), weak (DCI 100-450 mmHg.cm.s), and failed (DCI < 100 mm mmHg.cm.s) sequences. Univariate and multivariate analyses were performed to identify motor associations of abnormal reflux burden.

KEY RESULTS

Of 351 patients (52.1 ± 0.8 years, 67%F), 29.3% had AET > 6% and 61.8% had MNBI < 2292 ohms. On univariate analysis, both fragmented peristalsis and IEM associated with abnormal AET (P ≤ .01) and MNBI (P ≤ .03); reflux burden was more profound with >70% fragmented as well as ineffective sequences compared to ≤70% for each (P < .05 for each comparison). When weak and failed sequences within IEM were separately analyzed, ≥50% failed sequences predicted abnormal AET (P ≤ .009), and ≥50% weak sequences did not (P = .14). On multivariate regression, ≥50% failed sequences predicted abnormal AET (P = .02), and >70% ineffective sequences trended strongly (P = .069); >70% ineffective sequences predicted abnormal MNBI (P = .046), and >70% fragmented sequences trended strongly (P = .076).

CONCLUSIONS AND INFERENCES

Breaks in esophageal peristaltic integrity seen with fragmented and failed sequences are more relevant to abnormal esophageal acid burden than weak sequences.

Landslides and tsunamis predicted by incompressible smoothed particle hydrodynamics (SPH) with application to the 1958 Lituya Bay event and idealized experiment

Tsunamis caused by landslides may result in significant destruction of the surroundings with both societal and industrial impact. The 1958 Lituya Bay landslide and tsunami is a recent and well-documented terrestrial landslide generating a tsunami with a run-up of 524 m. Although recent computational techniques have shown good performance in the estimation of the run-up height, they fail to capture all the physical processes, in particular, the landslide-entry profile and interaction with the water. Smoothed particle hydrodynamics (SPH) is a versatile numerical technique for describing free-surface and multi-phase flows, particularly those that exhibit highly nonlinear deformation in landslide-generated tsunamis. In the current work, the novel multi-phase incompressible SPH method with shifting is applied to the Lituya Bay tsunami and landslide and is the first methodology able to reproduce realistically both the run-up and landslide-entry as documented in a benchmark experiment. The method is the first paper to develop a realistic implementation of the physics that in addition to the non-Newtonian rheology of the landslide includes turbulence in the water phase and soil saturation. Sensitivity to the experimental initial conditions is also considered. This work demonstrates the ability of the proposed method in modelling challenging environmental multi-phase, non-Newtonian and turbulent flows.

End-diastolic flow reversal limits the efficacy of pediatric intra-aortic balloon pump counterpulsation

BACKGROUND

Counterpulsation with an intra-aortic balloon pump (IABP) has not achieved the same success or clinical use in pediatric patients as in adults. In a pediatric animal model, IABP efficacy was investigated to determine whether IABP timing with a high-fidelity blood pressure signal may improve counterpulsation therapy versus a low-fidelity signal.

METHODS

In Yorkshire piglets (n = 19; weight, 13.0 ± 0.5 kg) with coronary ligation-induced acute ischemic left ventricular failure, pediatric IABPs (5 or 7 mL) were placed in the descending thoracic aorta. Inflation and deflation were timed with traditional criteria from low-fidelity (fluid-filled) and high-fidelity (micromanometer) blood pressure signals during 1:1 support. Aortic, carotid, and coronary hemodynamics were measured with pressure and flow transducers. Myocardial oxygen consumption was calculated from coronary sinus and arterial blood samples. Left ventricular myocardial blood flow and end-organ blood flow were measured with microspheres.

RESULTS

Despite significant suprasystolic diastolic augmentation and afterload reduction at heart rates of 105 ± 3 beats per minute, left ventricular myocardial blood flow, myocardial oxygen consumption, the myocardial oxygen supply/demand relationship, cardiac output, and end-organ blood flow did not change. Statistically significant end-diastolic coronary, carotid, and aortic flow reversal occurred with IABP deflation. Inflation and deflation timed with a high-fidelity versus low-fidelity signal did not attenuate systemic flow reversal or improve the myocardial oxygen supply/demand relationship.

CONCLUSIONS

Systemic end-diastolic flow reversal limited counterpulsation efficacy in a pediatric model of acute left ventricular failure. Adjustment of IABP inflation and deflation timing with traditional criteria and a high-fidelity blood pressure waveform did not improve IABP efficacy or attenuate flow reversal. End-diastolic flow reversal may limit the efficacy of IABP counterpulsation therapy in pediatric patients with traditional timing criteria. Investigation of alternative deflation timing strategies is warranted.

Smoothed particle hydrodynamics method applied to pulsatile flow inside a rigid two-dimensional model of left heart cavity

This paper aims to extend the application of smoothed particle hydrodynamics (SPH), a meshfree particle method, to simulate flow inside a model of the heart's left ventricle (LV). This work is considered the first attempt to simulate flow inside a heart cavity using a meshfree particle method. Simulating this kind of flow, characterized by high pulsatility and moderate Reynolds number using SPH is challenging. As a consequence, validation of the computational code using benchmark cases is required prior to simulating the flow inside a model of the LV. In this work, this is accomplished by simulating an unsteady oscillating flow (pressure amplitude: A = 2500 N ∕ m(3) and Womersley number: W(o)  = 16) and the steady lid-driven cavity flow (Re = 3200, 5000). The results are compared against analytical solutions and reference data to assess convergence. Then, both benchmark cases are combined and a pulsatile jet in a cavity is simulated and the results are compared with the finite volume method. Here, an approach to deal with inflow and outflow boundary conditions is introduced. Finally, pulsatile inlet flow in a rigid model of the LV is simulated. The results demonstrate the ability of SPH to model complex cardiovascular flows and to track the history of fluid properties. Some interesting features of SPH are also demonstrated in this study, including the relation between particle resolution and sound speed to control compressibility effects and also order of convergence in SPH simulations, which is consistently demonstrated to be between first-order and second-order at the moderate Reynolds numbers investigated.

Inhibition of topoisomerase I function by coralyne and 5,6-dihydrocoralyne

The antitumor agent coralyne and a number of structural analogues were found to be inhibitors of DNA topoisomerase I and were characterized biochemically. Several of these analogues stabilized the covalent binary complex formed between calf thymus topoisomerase I and pSP64 plasmid DNA; coralyne and 5,6-dihydrocoralyne had the greatest potency as inhibitors in this assay. In common with camptothecin, the effects of coralyne and 5,6-dihydrocoralyne were reversed in the presence of increasing salt concentration or temperature, consistent with the interpretation that both functioned mechanistically in a fashion analogous to camptothecin. The sequence specificity of DNA cleavage by coralyne and 5,6-dihydrocoralyne was also studied in comparison with camptothecin using a 471-bp DNA duplex as a substrate for topoisomerase I. Seven sites of cleavage were apparent, four of which were shared in common by coralyne, 5,6-dihydrocoralyne and camptothecin. Coralyne and 5,6-dihydrocoralyne produced cleavage at one sequence, 5'-TCTC decreases GTAA=3', that was not apparent in the presence of camptothecin; correspondingly, two cleavage bands appeared only when camptothecin was present. Coralyne and 5,6-dihydrocoralyne also inhibited topoisomerase I-mediated relaxation of supercoiled plasmid DNA. Coralyne was the most potent inhibitor of DNA relaxation; the effects of camptothecin and 5,6-dihydrocoralyne were roughly equal. At high concentrations, coralyne completely suppressed the formation of the topoisomerase I-DNA covalent binary complex.