New techniques to evaluate esophageal function

Practical multidisciplinary framework for the assessment and management of patients with unexplained chronic aerodigestive symptoms

OBJECTIVE

Patients experiencing unexplained chronic throat symptoms (UCTS) are frequently referred to gastroenterology and otolaryngology outpatient departments for investigation. Often despite extensive investigations, an identifiable structural abnormality to account for the symptoms is not found. The objective of this article is to provide a concise appraisal of the evidence-base for current approaches to the assessment and management of UCTS, their clinical outcomes, and related healthcare utilisation.

DESIGN

This multidisciplinary review critically examines the current understanding of aetiological theories and pathophysiological drivers in UCTS and summarises the evidence base underpinning various diagnostic and management approaches.

RESULTS

The evidence gathered from the review suggests that single-specialty approaches to UCTS inadequately capture the substantial heterogeneity and pervasive overlaps among clinical features and biopsychosocial factors and suggests a more unified approach is needed.

CONCLUSION

Drawing on contemporary insights from the gastrointestinal literature for disorders of gut-brain interaction, this article proposes a refreshed interdisciplinary approach characterised by a positive diagnosis framework and patient-centred therapeutic model. The overarching aim of this approach is to improve patient outcomes and foster collaborative research efforts.

Role of functional luminal imaging probe in the management of postmyotomy clinical failure

BACKGROUND AND AIMS

A small percentage of patients with esophageal dysmotility disorders (EDDs) fail to improve or relapse after management by laparoscopic Heller myotomy (LHM) and peroral endoscopic myotomy (POEM). In this study, we aimed to describe the role of functional luminal imaging probe (FLIP) in identifying patients who might benefit from lower esophageal sphincter (LES)-directed retreatment.

METHODS

This was a retrospective study at 6 tertiary care centers (United States, 4; Europe, 1; Asia, 1) between January 2015 and April 2021 involving patients with prior failed myotomy. The primary outcome was the impact of the use of FLIP on the management of patients with prior failed myotomy.

RESULTS

One hundred twenty-three patients (62 women [50%]; mean age, 53 ± 21.1 years) who underwent LHM (n = 53, 43%) or POEM (n = 70, 57%) for the management of achalasia (n = 98) or other EDDs (n = 25) had clinical failure at a median time of 10.8 months (interquartile range, .8-17.3) postprocedure. Twenty-nine patients had apposing "abnormal" diagnoses in terms of integrated relaxation pressure (IRP) >15 mm Hg on HRM and distensibility index (DI) <2.8 mm²/mm Hg on FLIP, with ultimate change in management noted in 15 patients (10 directed toward conservative management, 5 directed toward LES-directed retreatment). The impact of FLIP on both diagnosis and management was noted in 15 of 29 patients (52%). In the subgroup analysis of 44 patients who underwent LES-directed retreatment, clinical success was highest among patients with both abnormal IRP and DI (21/25 [84%]) versus patients with only abnormal IRP (8/14 [57%]) or only abnormal DI (3/5 [60%], P = .04), with DI at 40-mL distension volume on FLIP identified as an independent predictor of clinical success (odd ratio, 1.51; 95% confidence interval, 1.02-2.1; P = .03).

CONCLUSIONS

The finding of this study further suggests the important role of using FLIP in addition to HRM in evaluating patients with clinical failure postmyotomy.

The relationship between gastroesophageal reflux disease and recurrent wheezing in children

Gastroesophageal reflux disease occurs when gastric contents flow back into the esophagus and produce symptoms. Recurrent wheezing affects the quality of life for the patient and family. The association of gastroesophageal reflux with recurrent wheezing is suggested by different studies. The purpose of this study was to explore this relationship and to evaluate the outcome after appropriate treatment.A retrospective study on 85 children with recurrent wheezing, admitted in a pediatric gastroenterology regional center in Romania was performed. 24-hour continuous esophageal pH monitoring was used to evaluate the presence of gastroesophageal reflux and the results were interpreted using the Boix Ochoa score. All patients with positive score received treatment with proton pump inhibitors and they were evaluated again after 2 months.Gastroesophageal reflux was present in 71 children (83.5%), while 14 (16.5%) had a negative score, with a statistic significance (χ2 = 6.88, P = .0086, 95% confidence interval). After 2 months treatment with proton pump inhibitors, the Boix Ochoa score was still positive in 15 patients (21.13%).Recurrent wheezing is a solid reason for evaluating the presence of gastroesophageal reflux by 24-hour continuous esophageal pH-metry. Adequate treatment of gastroesophageal reflux solves also the recurrent wheezing in the majority of patients.

Clinical usefulness of esophagogastric junction distensibility measurement in patients with achalasia before and after peroral endoscopic myotomy

BACKGROUND/AIMS

This study aimed to determine the clinical efficacy of measuring the esophagogastric junction (EGJ) distensibility index (DI) in patients with achalasia before and after peroral endoscopic myotomy (POEM).

MATERIALS AND METHODS

Retrospective data were collected from 195 patients who underwent POEM from November 2014 to November 2017 at our clinic. The Eckardt score, high-resolution manometry, and EGJ distensibility were measured before and six months after POEM. Treatment failure was defined as a postprocedure Eckardt score >3 or patients who underwent repeat POEM.

RESULTS

The DI (mm2/mmHg) before and after POEM was 3.42±3.55 and 11.57±6.64, respectively (p<0.01). There was no difference in the DI between achalasia subtypes I, II, and III (11.45±6.24 versus 15.49±11.53 versus 13.27±9.49, p=0.22) or previous treatment history (15.39±10.85 versus 11.10±7.25, p=0.20). The DI was higher in patients with reflux esophagitis after POEM, but the difference was not significant (13.59±7.15 versus 12.54±10.9, p=0.571).

CONCLUSION

This study showed that EGJ distensibility measurement is useful to assess post-POEM outcomes. These findings suggest that the functional lumen imaging probe may be a useful method for assessing clinical efficacy of POEM in patients with achalasia. However, this is a costly procedure that requires experience.

Topographical plots of esophageal distension and contraction: effects of posture on esophageal peristalsis and bolus transport

Each swallow induces a wave of inhibition followed by contraction in the esophagus. Unlike contraction, which can easily be measured in humans using high-resolution manometry (HRM), inhibition is difficult to measure. Luminal distension is a surrogate of the esophageal inhibition. The aim of this study was to determine the effect of posture on the temporal and quantitative relationship between distension and contraction along the entire length of the esophagus in normal healthy subjects by using concurrent HRM, HRM impedance (HRMZ), and intraluminal ultrasound (US). Studies were conducted in 15 normal healthy subjects in the supine and Trendelenburg positions. Both manual and automated methods were used to extract quantitative pressure and impedance-derived features from the HRMZ recordings. Topographical plots of distension and contraction were visualized along the entire length of the esophagus. Distension was also measured from the US images during 10-ml swallows at 5 cm above the lower esophageal sphincter. Each swallow was associated with luminal distension followed by contraction, both of which traversed the esophagus in a sequential/peristaltic fashion. Luminal distension (US) and esophageal contraction amplitude were greater in the Trendelenburg compared with the supine position. Length of esophageal breaks (in the transition zone) were reduced in the Trendelenburg position. Change in posture altered the temporal relationship between distension and contraction, and bolus traveled closer to the esophageal contraction in the Trendelenburg position. Topographical contraction-distension plots derived from HRMZ recordings is a novel way to visualize esophageal peristalsis. Future studies should investigate if abnormalities of esophageal distension are the cause of functional dysphagia. NEW & NOTEWORTHY Ascending contraction and descending inhibition are two important components of peristalsis. High-resolution manometry only measures the contraction phase of peristalsis. We measured esophageal distension from intraluminal impedance recordings and developed novel contraction-distension topographical plots to prove that similar to contraction, distension also travels in a peristaltic fashion. Change in posture from the supine to the Trendelenburg position also increased the amplitude of esophageal distension and contraction and altered the temporal relationship between distension and contraction.

Genesis of Esophageal Pressurization and Bolus Flow Patterns in Patients With Achalasia Esophagus

BACKGROUND & AIMS

In patients with achalasia esophagus, swallows induce simultaneous pressure waves known as esophageal pressurization. We studied the mechanism of esophageal pressurization and bolus flow patterns in patients with type 2 or type 3 achalasia.

METHODS

We recorded high-resolution manometry with impedance and intraluminal ultrasound images concurrently in patients with type 2 achalasia (n = 6) or type 3 achalasia (n = 8) and in 10 healthy subjects (controls) during swallows of 5 mL of 0.5N saline. For each swallow, the ultrasound image was aligned with the pressure and impedance tracings to determine cavity and contact pressure, bolus arrival, bolus dwell time, and changes in muscle thickness at 5 cm and 10 cm above the lower esophageal sphincter.

RESULTS

In patients with type 2 achalasia, esophageal pressurization was associated with an increase in the muscle thickness and luminal narrowing but not complete luminal closure (ie, cavity pressure). Bolus arrival time in the distal esophagus after the onset of a swallow was delayed in patients with type 3 achalasia compared with control individuals because of early luminal closure. The early luminal closure was associated with a decrease in the muscle thickness. The bolus dwell time was shorter in patients with type 3 achalasia compared with control individuals. In patients with type 3 achalasia, the onset of simultaneous pressure wave was always a cavity pressure, but during contraction there were different periods of cavity and contact pressures in association with increases in muscle thickness that resulted in bolus segmentation.

CONCLUSIONS

We observed distinct mechanisms of esophageal pressurization and bolus flow patterns in patients with type 2 or type 3 achalasia esophagus compared with control individuals. These findings will increase our understanding of the mechanisms of dysphagia.

Pathophysiology and treatment of achalasia in a muscle mechanical perspective

This review provides a biomechanical perspective on the pathophysiology and treatment of achalasia. The esophagus is efficient in transporting ingested material to the stomach in healthy subjects. A fine balance exists between the peristaltic forces generated in the esophageal body (which herein is defined as the preload) and the resistance in the outlet, the esophago-gastric junction (which is defined as the afterload). Achalasia is a rare esophageal disease that progressively over many years challenges esophageal efficacy. Clinical features and current literature are interpreted using well-known muscle mechanics models and terms from cardiac mechanophysiology. The preload, afterload, length-tension, and strain softening concepts in particular are useful for understanding the remodeling induced by achalasia. The concepts are also useful in understanding the treatment that aim to reduce the lower esophageal sphincter pressure that does not relax sufficiently in achalasia. These treatments cover endoscopic or laparoscopic myotomy, pneumatic balloon dilation, and Botox injections. In addition to the intended reduction of the afterload for aboral transport of ingested materials, the treatments tend to induce gastroesophageal reflux in some patients because they obliterate an important component in the reflux barrier.

What Is the Future of Impedance Planimetry in Gastroenterology?

The gastrointestinal (GI) tract is efficient in transporting ingested material to the site of delivery in healthy subjects. A fine balance exists between peristaltic forces, the mixing and delivery of the contents, and sensory signaling. This fine balance is easily disturbed by diseases. It is mandatory to understand the pathophysiology to enhance our understanding of GI disorders. The inaccessibility and complex nervous innervation, geometry and mechanical function of the GI tract make mechanosensory evaluation difficult. Impedance planimetry is a distension technology that assesses luminal geometry, mechanical properties including muscle dynamics, and processing of nociceptive signals from the GI tract. Since standardized models do not exist for GI muscle function in vivo, models, concepts, and terminology must be borrowed from other medical fields such as cardiac mechanophysiology. The review highlights the impedance planimetric technology, muscle dynamics assessment, and 3 applied technologies of impedance planimetry. These technologies are the multimodal probes that assesses sensory function, the functional luminal imaging probe that dynamically measures the geometry of the lumen it distends, and Fecobionics that is a simulated feces providing high-resolution measurements during defecation. The advanced muscle analysis and 3 applied technologies can enhance the quality of future interdisciplinary research for gaining more knowledge about mechanical function, sensory-motor disorders, and symptoms. This is a step in the direction of individualized treatment for GI disorders based on diagnostic subtyping. There seems to be no better alternatives to impedance planimetry, but only the functional luminal imaging probe is currently commercially available. Wider use depends on commercialization of the multimodal probe and Fecobionics.

The motility of esophageal sphincters during liquid and solid bolus swallows: a multicenter normative value study of high-resolution manometry in China

BACKGROUND

It is gradually accepted that solid bolus swallow needs to be added to the procedure of manometry. The motility differences in the upper esophageal sphincter (UES) and lower esophageal sphincter (LES) were not well described. Sierra Scientific Instruments solid-state high-resolution manometry (HRM) system, the most popular HRM system in China, lacks the Chinese normative values for both liquid and solid bolus swallow parameters.

METHODS

The esophageal HRM data of 88 healthy volunteers were analyzed. The parameters of both sphincters in resting stage were summarized and those during solid and liquid swallows were compared.

KEY RESULTS

Normative HRM values of sphincter parameters in solid and liquid bolus swallows in China were established. The UES residual pressure of solid bolus swallows was lower than that of liquid bolus (0.3±5.5 mm Hg vs 4.8±5.9 mm Hg, P=.000). The time parameters of UES relaxation between two types of bolus swallows were similar. In solid bolus swallows, the intrabolus pressure (IBP) (13.8±5.1 mm Hg vs 10.9±5.7 mm Hg, P=.000) and LES relaxation time (11.0±2.1 seconds vs 8.7±1.3 seconds, P=.000) were higher. The 4-second integrated relaxation pressure between both bolus swallows was similar.

CONCLUSIONS & INFERENCES

The function of the UES and LES between solid and liquid bolus swallows is different. Chinese HRM parameters are different from the Chicago Classification (http://www.chictr.org.cn, Number ChiCTR-EOC-15007147).

Peroral endoscopic myotomy for the treatment of esophageal achalasia: systematic review and pooled analysis

Peroral endoscopic myotomy (POEM) is a novel approach to performing esophageal myotomy for the treatment of achalasia. This review aims to assess subjective and objective metrics of achalasia treatment efficacy, perioperative adverse events and the incidence of postoperative gastroesophageal reflux disease in patients treated with POEM. Secondary aims include a pooled analysis comparison of the clinical outcomes and procedural safety of POEM versus laparoscopic Heller's myotomy (LHM). A systematic review of the literature, up to and including January 15, 2015, was conducted for studies reporting POEM outcomes. Studies comparing POEM to LHM were also included for the purpose of pooled analysis. Outcomes from 1122 POEM patients, from 22 studies, are reported in this systematic review. Minor operative adverse events included capno/pneumo-peritoneum (30.6%), capno/pneumo-thorax (11.0%) and subcutaneous emphysema (31.6%). Major operative adverse events included mediastinal leak (0.3%), postoperative bleeding (1.1%) and a single mortality (0.09%). There was an improvement in lower esophageal sphincter pressure and timed barium esophagram column height of 66% and 80% post-POEM, respectively. Symptom improvement was demonstrated with a pre- and post-POEM Eckardt score ± standard deviation of 6.8 ± 1.0 and 1.2 ± 0.6, respectively. Pre- and post-POEM endoscopy showed esophagitis in 0% and 19% of patients, respectively. The median (interquartile range) points scored for study quality was 15 (14-16) out of total of 32. Pooled analysis of three comparative studies between LHM and POEM showed similar results for adverse events, perforation rate, operative time and a nonsignificant trend toward a reduced length of hospital stay in the POEM group. In conclusion, POEM is a safe and effective treatment for achalasia, showing significant improvements in objective metrics and achalasia-related symptoms. Randomized comparative studies of LHM and POEM are required to determine the most effective treatment modality for achalasia.

Characterization and follow-up of esophagogastric junction outflow obstruction detected by high resolution manometry

BACKGROUND

Esophagogastric junction outflow obstruction (EGJOO) is a newly described diagnostic entity growing in importance due to the use of high resolution manometry (HRM). There is little knowledge regarding its incidence, etiopathogeny, long-term evolution, and most suitable treatment. Our objective was to increase the awareness of EGJOO to optimize the management of these patients.

METHODS

We conducted a historical (retrospective and prospective) study of patients diagnosed with EGJOO using HRM combined with multichannel intraluminal impedance, comparing their manometric and impedance characteristics with those of a control group. Symptoms, etiology of obstruction, acid exposure, clinical course (and its associated factors), and response to treatment were also evaluated in the EGJOO group.

KEY RESULTS

Forty-four subjects were included (28 patients and 16 controls). Esophagogastric junction outflow obstruction patients presented incomplete esophageal transit more frequently than controls. Patients with structural obstruction had dysphagia more frequently than patients with functional obstruction, and different manometric, impedance, and pH-metric patterns. Over one-third of the EGJOO patients presented a spontaneous resolution of symptoms without EGJOO treatment. In the multivariate analysis, the variables associated with this spontaneous symptomatic resolution included typical symptoms of gastro-esophageal reflux disease or epigastralgia as the main symptom and resting or basal pressure of the upper esophageal sphincter <50 mmHg.

CONCLUSIONS & INFERENCES

The majority of EGJOO patients presented intact peristalsis which may compensate for the lack of EGJ relaxation. In the EGJOO patients presenting favorable factors associated with a spontaneous resolution of symptoms, invasive treatments should be considered with special caution. Structural etiologies are more amenable to management, while the remainder may improve without intervention.

Gastroesophageal reflux symptoms not responding to proton pump inhibitor: GERD, NERD, NARD, esophageal hypersensitivity or dyspepsia?

Gastroesophageal reflux (GER) is a common gastrointestinal process that can generate symptoms of heartburn and chest pain. Proton pump inhibitors (PPIs) are the gold standard for the treatment of GER; however, a substantial group of GER patients fail to respond to PPIs. In the past, it was believed that acid reflux into the esophagus causes all, or at least the majority, of symptoms attributed to GER, with both erosive esophagitis and nonerosive outcomes. However, with modern testing techniques it has been shown that, in addition to acid reflux, the reflux of nonacid gastric and duodenal contents into the esophagus may also induce GER symptoms. It remains unknown how weakly acidic or alkaline refluxate with a pH similar to a normal diet induces GER symptoms. Esophageal hypersensitivity or functional dyspepsia with superimposed heartburn may be other mechanisms of symptom generation, often completely unrelated to GER. Detailed studies investigating the pathophysiology of esophageal hypersensitivity are not conclusive, and definitions of the various disease states may overlap and are often confusing. The authors aim to clarify the pathophysiology, definition, diagnostic techniques and medical treatment of patients with heartburn symptoms who fail PPI therapy.

High resolution manometry patterns distinguish acid sensitivity in non-cardiac chest pain

BACKGROUND

High resolution manometry (HRM) has demonstrated two distinct smooth muscle contraction segments in the esophageal body; changes in these segments typify certain esophageal disorders. We investigated segmental characteristics in subgroups of non-cardiac chest pain (NCCP).

METHODS

32 NCCP subjects were segregated into a GERD group (ambulatory pH testing off antisecretory therapy showing elevated total acid exposure time, AET≥4.0% and positive symptom association probability, SAP) and an acid sensitive group (normal AET and positive SAP). HRM Clouse plots were analyzed; smooth muscle segment lengths, pressure amplitude peaks were measured for segment 2 and segment 3 (proximal and distal smooth muscle segments). Pressure volumes were determined in mmHg cm(-1) s(-1) for each peristaltic segment, and ratios of segment 3:segment 2 calculated. Values were compared to a cohort of 14 normal controls.

KEY RESULTS

A distinctive shift in peak contraction amplitude to segment 3 was evident in the acid sensitive group (segment 2, 100.03±11.06mmHg, segment 3, 145.23± 10.29mmHg, P=0.006). Pressure volumes were similarly shifted to segment 3 (segment 2: 855.3 ± 135.1 mmHg cm(-1)  s(-1) , segment 3: 2115.2±218.6 mmHg cm(-1) s(-1) , P<0.005). In contrast, peak amplitude and pressure volume were near equal in the two segments in GERD and control groups. A threshold segment 3:segment 2 pressure volume ratio of 1.9 had the best performance characteristic for segregating acid sensitivity subjects from all GERD and control subjects.

CONCLUSIONS & INFERENCES

Shift in contractile vigor to the third peristaltic segment may be seen in acid sensitive subjects. HRM characteristics of smooth muscle contraction segments are of value in making this determination.

Swallow evaluation during multichannel intraluminal impedance and pH: an alternate method to assess esophageal transit

BACKGROUND

Twenty-four-hour multichannel intraluminal impedance and pH (MII-pH) esophageal monitoring allows detection of both acid and nonacid gastroesophageal reflux episodes. The MII-pH catheter contains 6 impedance segments placed 3, 5, 7, 9, 15, and 17 cm above the lower esophageal sphincter (LES), plus a pH electrode at 5 cm. Multichannel intraluminal impedance and esophageal manometry (MII-EM) allows both functional and manometric evaluation of the esophagus. The MII-EM catheter contains 4 impedance measuring segments (5, 10, 15, and 20 cm above LES) and 5 solid state pressure transducers (within the LES and 5, 10, 15, and 20 cm above LES). Five milliliter saline boluses are given in the recumbent position when performing an MII-EM study. In our laboratory, all patients have an MII-EM study performed before an MII-pH study. In many laboratories, MII-pH is done without earlier MII-EM.

AIM

To assess accuracy of swallows given before ambulatory MII-pH monitoring in detecting esophageal transit abnormalities.

MATERIALS AND METHODS

Hundred consecutive adult patients, prospectively studied (64 female; mean age = 52.6 y), presenting to our laboratory for MII-EM and 24-hours MII-pH study, also received 10 saline swallows in the recumbent position at the beginning of the MII-pH study. Impedance for these swallows was assessed for the presence of complete or incomplete transit; defined as presence of bolus entry in the 17 cm segment and bolus exit in the 15, 9, and 5 cm segments; defined by a rise in impedance above 50% between baseline and the nadir, and remaining above this value for at least 5 seconds. Of 10 swallows, the presence of 8 or more complete swallows satisfies the MII-EM criterion for diagnosis of complete transit. These findings were blindly compared with those of the 10 saline swallows on the MII-EM study.

RESULTS

In 93% of patients, the MII-pH swallows gave identical transit diagnosis to the MII-EM. In 2 patients, the diagnosis changed from incomplete transit on MII-EM to complete on MII-pH, and in 5 patients from complete transit on MII-EM to incomplete on MII-pH. With both methods, there were 64 patients with complete transit and 29 with incomplete transit. Thus, MII-pH swallows had a sensitivity of 94% and a specificity of 93% for detection of esophageal transit abnormalities.Comparing the swallow diagnosis for each patient, we found that there was a highly significant correlation (P < 0.0001) for the number swallows with complete (Pearson r = 0.89) and incomplete bolus transits (Pearson r = 0.89). There was also a significant correlation (P < 0.0001) in bolus transit time between both methods (Pearson r = 0.64).

CONCLUSIONS

Use of 10 saline swallows at the beginning of MII-pH studies is accurate, missing bolus transit abnormality in only 2 of 100 patients. It is also highly sensitive and specific for detection of esophageal transit abnormalities. This method allows detection of patients in whom further evaluation of esophageal function may be warranted.