Gastrointestinal Manometry

Number: 0616

Table Of Contents

Policy

Scope of Policy

This Clinical Policy Bulletin addresses gastrointestinal manometry.

1. Medical Necessity

   Aetna considers the following medically necessary:

   1. Antroduodenal manometry for members with dyspepsia, gastroparesis, or chronic intestinal pseudo-obstruction with unexplained upper gastrointestinal symptoms (e.g., nausea, vomiting) if gastric emptying is normal or equivocal and severe symptoms persist despite empiric therapeutic trials of conservative management (e.g., twice-daily proton pump inhibitors, prokinetics agents, etc.);
   2. Anorectal manometry as well as rectal sensation, tone, and compliance test for evaluating anorectal function in individuals with chronic constipation who have failed to respond to laxatives; and individuals with functional/structural fecal incontinence who have failed to respond to at least 3 months of conservative measures (e.g., supportive care, medical therapy, and pelvic floor physical therapy), and have a negative endoscopic (flexible sigmoidoscopy and/or colonoscopy) evaluation;
   3. Colonic motility studies (colonic manometry) to guide decision-making for surgery in children with refractory colonic motility / defecatory disorders;
   4. High-resolution esophageal manometry for the diagnosis of esophageal motility disorders in persons with dysphagia (including symptoms of achalasia, rumination syndrome and PPI-refractory chest pain), and for evaluation of persons undergoing anti-reflux surgery.

2. Experimental, Investigational, or Unproven

   The following procedures are considered experimental, investigational, or unproven because the effectiveness of these approaches has not been established:

   1. Antroduodenal manometry for all other indications (other than the ones listed above).  Antroduodenal manometry has no proven additional value if tests of gastric function reveal delayed emptying or abnormal myoelectrical activity;
   2. Colonic motility studies for all other indications (other than the ones listed above);
   3. Use of magnetic resonance imaging (MRI) capsule marker methods for measurement of whole gut transit in functional gastro-intestinal disorders; and for all other indications;
   4. Pharyngeal high-resolution manometry with impedance for the evaluation of dysphagia.

3. Related Policies

   • CPB 0396 - Gastrointestinal Function: Selected Tests

Background

This policy is consistent with the conclusions of a technical review by the American Gastroenterological Association (AGA) (Quigley et al, 2001).

Antroduodenal manometry is a relatively new technique for the evaluation of gastric and small intestinal motor function. Antroduodenal manometry is used to measure the contractile activity of the distal stomach and duodenum. Changes in intra-luminal pressure of the stomach and duodenum are measured through perfusion ports or solid-state transducers incorporated in a catheter that is positioned under fluoroscopic guidance. Results are recorded and may be analyzed either by direct visual inspection or using a computer. Recordings may last from 5 hours (stationary study) to 24 hours (ambulatory study).

Intra-luminal pressure changes are measured both in the fasting state and after meals. In the fasting state, the presence of the muscle contractions and their site of initiation, direction of propagation, frequency, and duration are assessed. After the meal, conversion to the fed state is identified, and the duration of the fed pattern is calculated. Post-prandial antral hypomotility is a common finding among those with unexplained nausea and vomiting and delayed gastric emptying, and manometry has also been reported as useful in identifying those with primary or diffuse motor disorders. However, the interpretation of antroduodenal manometric recordings requires substantial experience and recognition of the considerable range of normal variation. The specificity of many reportedly abnormal patterns has rarely been confirmed by correlation with histological studies.

A technical review from the AGA (Quigley et al, 2001) stated that, if tests of gastric function reveal delayed emptying or abnormal myoelectrical activity, antroduodenal manometry is of little added value. Antroduodenal manometry may be indicated when the gastric emptying or electrogastrography results are normal or equivocal and severe symptoms persist despite empiric therapeutic trials. Occasionally, findings consistent with chronic intestinal pseudo-obstruction may be revealed or features consistent with mechanical obstruction identified in patients in whom they had not been detected radiographically. A normal antroduodenal manometry result may be of value in patients with unexplained nausea and vomiting: by demonstration of normal motor function in the antrum and the duodenum, any lingering questions regarding dysmotility can be resolved and the diagnostic evaluation redirected elsewhere.

Steinbrueckner and associates (1996) reported that a motility pattern consisting of continuous simultaneous contractions at high frequency from the antrum down to the upper jejunum was associated with repeated vomiting.

Verhagen and colleagues (1999) evaluated the outcome of antroduodenal manometry studies and their effect on the clinical treatment of patients. Nausea and vomiting were the most predominant symptoms (37.4 %). In 49.5 % of the cases, the test was performed due to suspicion of a generalized motor disorder. A normal outcome was found in 37 studies. Non-specific motor abnormalities were reported in 72 % of the studies with an abnormal outcome. Pseudo-obstruction was diagnosed in 20 %. The manometric studies resulted in a new therapy in 12.6 %, a new diagnosis in 14.9 %, and referral to another specialist in 8 %. A positive clinical impact was found in 28.7 % of the patients. The authors concluded that antroduodenal manometry can be a helpful diagnostic technique in a specialized center.

These findings are in accord with those of Hyman et al (1990), who stated that antroduodenal manometry is a useful technique that elucidates the underlying gastrointestinal motility disorder present in the majority of children and adolescents with severe functional symptoms.

Glia and Lindberg (1998) studied the antroduodenal motor activity in 20 patients to ascertain whether patients with slow-transit constipation may have a generalized intestinal motor disorder. They found a significant proportion of patients with slow-transit constipation have manometric findings that indicate a generalized motor disorder of the gut. However, the clinical significance of these findings is unclear.

Byrne and Quigley (1997) concluded that in the evaluation of suspected foregut motor dysfunction, antroduodenal manometry may provide clinically useful information in selected patients; information which may not be available from standard diagnostic tests, including nuclear medicine gastric-emptying studies.

Stanghellini et al (2000) stated that only patients who remain undiagnosed after extensive traditional work-up and fail repeated courses with medical therapy should be referred for the manometric test.

Sha and colleagues (2009) evaluated gastric slow waves, antral and duodenal motility simultaneously, and ascertained the correlation among all these measures in patients with functional dyspepsia. A total of 31 patients with functional dyspepsia were assessed for severity of upper gastrointestinal symptoms with the electrogastrography (EGG) and ADM. The EGG and ADM were recorded for 3 to 4 hours in the fasting state and for 2 hours after a solid meal. Computerized spectral analysis methods were used to compute various EGG parameters. The EGG was abnormal in 71.0 % of patients. The abnormalities included normal slow waves lower than 70 % in the fasting state (51.6 % of patients) and in the fed state (48.4 % of patients), a decrease in dominant power in 28.9 % of patients. Antral motility was abnormal in 80.6 % of patients and duodenal motility was abnormal in 74.2 % of patients. For the EGG and antral motility, 19 of 31 patients had both abnormal EGG and abnormal antral motility; 2 of 31 patients had both normal EGG and normal antral motility. For the EGG and duodenal motility, these values were 16/31 and 2/31, respectively. By both EGG and ADM, abnormal gastric motor function was found in 93.5 % of patients. However, quantitative one-to-one correlation between any of the EGG parameters and the antroduodenal dysmotility was not noted. The patients showed high symptom scores especially to upper abdominal pain, nausea, and belch. No one-to-one correlation was noted between the symptom scores and any of the EGG or motility parameters. The authors concluded that more than two-thirds of patients with functional dyspepsia have abnormalities in the EGG and antral/duodenal motility. The sensitivity of these 2 different methods is essentially the same. Electrogastrography and ADM can complement each other in demonstrating gastric motor dysfunction in patients with functional dyspepsia.

Anorectal manometry (AM) measures the pressures of the anal sphincter muscles, the sensation in the rectum, as well as the neural reflexes needed for normal bowel movements. Anorectal manometry uses a pressure sensitive tube to check the sensitivity and function of the rectum. It also measures the ability of the anal sphincter muscles to respond to signals. Anorectal manometry has been used to evaluate patients with chronic constipation or fecal incontinence. The rectal sensation, tone, and compliance test measures the sensory, motor and biomechanical function of the rectum.

Noviello et al (2009) evaluate the role of AM in children with severe constipation. From October 2003 to October 2006, a total of 85 children aged more than 1 year with severe constipation were seen. The mean age was 5 years (range of 1 to 13). At presentation, every child had abdominal and rectal examination in order to identify abdominal distension or fecal masses. Bowel preparation with enemas was performed before AM in patient with a rectal fecaloma. Myoelectric activity of the internal anal sphincter and resting anal tone was recorded; recto-anal inhibitory reflex (RAIR) was tested to exclude Hirschsprung's disease. Anal tone was considered normal until 50 cm H(2)O. When the RAIR was absent, the patient underwent rectal suction biopsies (RSB) for histology and acetylcholinesterase histochemistry. In cases of normal or high anal tone with the RAIR present, the child had bowel cleaning, medical treatment, 2- and 6-month follow-up. Children with ineffective treatment at follow-up underwent RSB. In case of HD, a laparoscopic-assisted endorectal pull-through (ERPT) according to Georgeson's technique was performed. A total of 70 % of the patients had bowel preparation before AM. In 4 patients the AM was impossible to assess because of crying. In 28 patients, the anal tone result was higher than 50 cm H(2)O and local treatment with anesthetic agents was used for 8 weeks. Seventeen patients underwent RSB: 11 patients with RAIR absent/unclear, 4 non-cooperative children and 2 patients with ineffective medical treatment at follow-up. Hirschsprung's disease was diagnosed in 2 patients and laparoscopic-assisted ERPT was performed. The remaining patients had good results at 6-month follow-up. The authors concluded that AM is a non-invasive diagnostic tool to study the mechanism of defecation in children with constipation in order to prescribe the appropriate treatment. This procedure can be used in every child aged more than 1 year with severe constipation and assessment of the RAIR can select the cases for RSB.

Pucciani and Ringressi (2012) evaluated the clinical usefulness of AM in patients affected by obstructed defecation (OD). Between January 2007 and December 2010, a total of 379 patients (287 women and 92 men) affected by OD were evaluated. After a preliminary clinical evaluation, defecography and AM were performed. The results were compared with those from 20 healthy control subjects. Overall anal resting pressure was not significantly different between patients and controls. Maximal voluntary contraction (MVC) data were significantly lower when compared with those of controls (p < 0.01). The straining test was considered positive in 143 patients. No significant difference was noted between patients and controls in maximal tolerated volume data. Patients had a significantly higher conscious rectal sensitivity threshold than controls (p < 0.02). The authors concluded that a positive straining test, low MVC and impaired rectal sensation are the main abnormalities detected by AM in patients with OD.

In a meta-analysis, Videlock et al (2013) estimated the prevalence of abnormal findings associated with dyssynergic defecation (DD) across testing modalities in patients referred for physiological testing for chronic constipation (CC). Systematic search of Medline, Embase and PubMed databases were conducted. These researchers included full manuscripts reporting DD prevalence in CC, and specific findings at pelvic floor diagnostic tests. Random effects models were used to calculate pooled DD prevalence (with 95 % confidence interval [CI]) according to individual tests and specific findings. A total of 79 studies on 7,581 CC patients were included. The median prevalence of any single abnormal finding associated with DD was 37.2 %, ranging from 14.9 % (95 % CI: 7.9 to 26.3) for absent opening of the anorectal angle (ARA) on defecography to 52.9 % (95 % CI: 44.3 to 61.3) for a dyssynergic pattern on ultrasound. The prevalence of a dyssynergic pattern on AM was 47.7 % (95 % CI: 39.5 to 56.1). The prevalence of DD was similar across specialty and geographic area as well as when restricting to studies using Rome criteria to define constipation. The authors concluded that dyssynergic defecation is highly prevalent in CC and is commonly detected across testing modalities, type of patient referred, and geographical regions. They believed that the lower prevalence of findings associated with DD by defecography supports use of AM and balloon expulsion testing as an initial evaluation for CC.

The consensus statement of the Italian Association of Hospital Gastroenterologists and Italian Society of Colo-Rectal Surgery (AIGO/SICCR) on “Diagnosis and treatment of chronic constipation and obstructed defecation” (Bove et al, 2012) stated that “Colonic transit and anorectal manometry define the pathophysiologic subtypes. Balloon expulsion is a simple screening test for defecatory disorders, but it does not define the mechanisms. Defecography detects structural abnormalities and assesses functional parameters …. All these investigations are indicated to differentiate between slow transit constipation and obstructed defecation because the treatments differ between these conditions”.

The AGA’s medical position statement on “Constipation” (Bharucha et al, 2013) stated that “A careful digital rectal examination that includes assessment of pelvic floor motion during simulated evacuation is preferable to a cursory examination without these maneuvers and should be performed before referral for anorectal manometry. However, a normal digital rectal examination does not exclude defecatory disorders …. Anorectal manometry and a rectal balloon expulsion should be performed in patients who fail to respond to laxatives (Strong Recommendation, Moderate-Quality Evidence)”.

Colon manometry or colonic motility testing records intra-luminal pressures within the colon using a manometric catheter, which is positioned endoscopically and clipped to the colonic mucosa. Pressure activity is recorded continuously for a minimum of 6 hours. This test has been proposed to evaluate defecation disorders (e.g., chronic constipation) and motility abnormalities.

Colonic Manometry (Colonic Motility Testing)

An American Gastroenterological Association guideline on nausea and vomiting (AGA, 2001) concluded that “the place of such tests of motor function as gastric emptying studies, electrogastrography, and manometry have not been defined, and the yield of such diagnostic studies has not been adequately compared with a therapeutic trial of an antiemetic and/or prokinetic agents." An American Gastroenterological Association guideline on constipation (AGA, 2000) stated that colonic manometry “is not generally available and is not appropriate for most patients, except in research settings.” The consensus opinion of the American Motility Society Clinical GI Motility Testing Task Force on the performance and clinical utility of EGG (Parkman et al, 2003) stated that no therapies have convincingly demonstrated in controlled studies that correcting abnormalities detected by EGG improves upper gastrointestinal symptoms. Proposed clinical indications for performance of EGG in patients with unexplained nausea, vomiting and dyspeptic symptoms must be validated by prospective controlled investigations.

Singh and colleagues (2013) examined if colonic manometric evaluation is useful for characterizing colonic sensorimotor dysfunction and for guiding therapy in slow transit constipation (STC). In 80 patients (70 females) with STC, 24-hr ambulatory colonic manometry was performed in by placing a 6-sensor solid-state probe, along with assessment of colonic sensation with Barostat. Anorectal manometry was also performed. Manometrically, patients were categorized as having colonic neuropathy or myopathy based on gastro-colonic response, waking response and high amplitude propagated contractions (HAPC); and based on colonic sensation, as colonic hyposensitivity or hypersensitivity. Clinical response to pharmacological, biofeedback, and surgical treatment was assessed at 1 year and correlated with manometric findings. A total of 47 (59 %) patients who had abnormal colonic manometry, with features suggestive of neuropathy (26 %), and myopathy (33 %); 41 % had normal colonic manometry. Patients who had abnormal colonic sensation were 74 % and 61 % had overlapping dyssynergic defecation. Patients with neuropathy were more likely to have colonic hyposensitivity; 64 % of patients with colonic myopathy or normal manometry improved with medical/biofeedback therapy when compared to 15 % with colonic neuropathy (p < 0.01). Selected patients with colonic neuropathy had excellent response to surgery, but many developed bacterial overgrowth. The authors concluded that colonic manometry demonstrated significant colonic sensorimotor dysfunction in STC patients and revealed considerable pathophysiological heterogeneity. They stated that it can be useful for characterizing the underlying pathophysiology and for guiding clinical management in STC, especially surgery. The major drawback of this study was the lack of a controlled comparator group.

Wiklendt et al (2013) developed an automated analysis technique that can reliably differentiate the motor patterns of patients with STC from those recorded in healthy controls. Pancolonic manometric data were recorded from 17 patients with STC and 14 healthy controls. The automated analysis involved calculation of an indicator value derived from cross-correlations calculated between adjacent recording sites in a manometric trace. The automated technique was conducted on blinded real data sets (observed) and then to determine the likelihood of positive indicator values occurring by chance, the channel number within each individual data set were randomized (expected) and reanalyzed. In controls, the observed indicator value (3.2 ± 1.4) was significantly greater than that predicted by chance (0.8 ± 1.5; p < 0.0001). In patients, the observed indicator value (-2.7 ± 1.8) did not differ from that predicted by chance (-3.5 ± 1.6; P = 0.1). The indicator value for controls differed significantly from that of patients (p < 0.0001), with all individual patients falling outside of the range of indicator values for controls. The authors concluded that automated analysis of colonic manometry data using cross-correlation separated all patients from controls. They stated that this automated technique indicated that the contractile motor patterns in STC patients differ from those recorded in healthy controls. The analytical technique may represent a means for defining subtypes of constipation. The major drawback of this study was its small sample size (n = 17).

An UpToDate review on “Motility testing: When does it help?” (Lembo, 2014) states that “Specialized motility tests such as antroduodenal manometry, electrogastrography, and colonic manometry are under development and will not be discussed”. Furthermore, an UpToDate review on “Constipation in children: Etiology and diagnosis” (Ferry, 2014) discusses the use of AM as well as colon transit studies; however, it does not mention colonic manometry/colonic motility testing,

Dinning et al (2015) stated that in the esophagus, high-resolution manometry (HRM) has become a standard diagnostic tool in the investigation of suspected motility disorders. However, at the opposite end of the digestive tract (i.e., the colon and anorectum), the use of HRM still remains in its infancy, with relatively few published studies in the scientific literature. Further, the clinical utility of those studies that have been performed is largely undetermined. These investigators reviewed all of the HRM studies published to date from both the colon and anorectum, explored the catheter types used, and attempts to determine the worth of HRM over traditional “low-resolution” recordings from the same regions.

Koppen and colleagues (2016) stated that children with intractable functional constipation (FC) may eventually require surgery, often guided by motility testing. However, there are no evidence-based guidelines for the surgical management of intractable FC in children. These investigators evaluated the diagnostic and surgical approach of pediatric surgeons and pediatric gastroenterologists towards children with intractable FC. A survey was administered to physicians attending an international conference held simultaneously in Columbus, OH and Nijmegen (the Netherlands). The survey included 4 questions based on cases with anorectal and colonic manometry results. A total of 74 physicians completed the questionnaire. Anorectal manometry was used by 70 %; 52 % of them would consider anal sphincter botulinum toxin injections for anal achalasia and 21 % would use this to treat dyssynergia. Colonic manometry was used by 38 %; 57 % of them reported to use this to guide surgical decision-making. The surgical approach varied considerably among responders answering the case questions based on motility test results; the most commonly chosen treatments were antegrade continence enemas and anal botulinum injections. The authors concluded that surgical decision-making for children with intractable FC differs among physicians. They stated that there is a need for clinical guidelines regarding the role of anorectal and colonic manometry in surgical decision-making in children with intractable FC.

An UpToDate review on “Etiology and evaluation of chronic constipation in adults” (Wald, 2017) states that “Colonic manometry evaluates intraluminal pressure activity of the colon and rectum and provides detailed information about the qualitative aspects such as pattern of motor activity and quantitative aspects of colonic motility. It can be combined with a barostat apparatus to assess colonic tone, compliance, and sensation. Patients can be identified to have normal, myopathic, or neuropathic colon as well as sensory dysfunction. As yet, there is no evidence that such information has added value to the management of chronic constipation in clinical practice and this test is available for clinical use in only selected centers”.

In summary, there is currently insufficient evidence regarding the effectiveness of colon manometry or colonic motility testing. Patient selection criteria and the role of colonic manometry in the management of motility abnormalities (e.g., refractory constipation) must be better defined in well-designed studies.

In an editorial on “Colonic manometry in chronic constipation”, Chen and Huizinga (2018) stated that “In comparison with children, colonic manometry is rarely pursued in adults, and is available only in limited centers, and deemed of uncertain clinical relevance. Colonic manometry, as a clinical service, as opposed to a research procedure, is aimed at determining whether high-amplitude propagating contractions (HAPC) are generated under baseline conditions, in response to a meal, and in response to bisacodyl given in the proximal colon … Nevertheless, much is still to be learned from high-resolution colonic manometry (HRCM). Since pressure patterns are not equivalent to contraction patterns, more knowledge regarding the relationships between pressure and contraction is needed in order to correctly interpret HRCM results. We recently learned through a study in the rabbit colon that simultaneous pressure waves appear to be initiated by fast-propagating circumferential circular muscle contractions. With HRCM, retrograde cyclic motor patterns are recognized in the distal colon as part of the mechanism to maintain continence; abnormalities in this pattern may be related to the pathophysiology of constipation”.

Colonic Motility Studies / Colonic Manometry to Guide Decision-Making for Surgery in Children with Refractory Colonic Motility / Defecatory Disorders

Rao and associates (2004) stated that the colonic neuromuscular dysfunction in patients with constipation and the role of colonic manometry is incompletely understood. These researchers studied prolonged colonic motility and evaluated its clinical significance; 24-hour ambulatory colonic manometry was performed in 21 patients with slow-transit constipation and 20 healthy controls by placing a 6-sensor solid-state probe up to the hepatic flexure. Quantitative and qualitative manometric analysis was performed in 8-hour epochs; subjects were followed-up for 1 year. Constipated patients showed fewer pressure waves and lower area under the curve (AUC) (p < 0.05) than controls during daytime, but not at night. Colonic motility induced by waking or meal was decreased (p < 0.05) in patients. High-amplitude propagating contractions (HAPCs) occurred in 43 % of patients compared to 100 % of controls and with lower incidence (1.7 versus 10.1, p < 0.001) and propagation velocity (p < 0.04). Manometric features suggestive of colonic neuropathy were observed in 10, myopathy in 5, and normal profiles in 4 patients; 7 patients with colonic neuropathy underwent colectomy with improvement. The remaining patients were managed conservatively with 50 % improvement at 1 year. The authors concluded that patients with slow-transit constipation exhibited either normal or decreased pressure activity with manometric features suggestive of colonic neuropathy or myopathy as evidenced by absent HAPC or attenuated colonic responses to meals and waking. These researchers stated that in refractory patients, colonic manometry may be useful in characterizing the underlying pathophysiology and in guiding therapy.

Brown and colleagues (2005) noted that patients with rectal prolapse have abnormal hind-gut motility. These investigators examined the effect of rectal prolapse surgery on colonic motility. A total of 12 patients undergoing sutured rectopexy were studied before and 6 months after surgery by colonic manometry, colonic transit study and clinical assessment of bowel function. The results were compared with those from 7 control subjects. Before surgery, colonic pressure was greater in patients than controls (p < 0.050); controls responded to a meal stimulus by increasing colonic pressure; this increase was absent in patients. After rectopexy, colonic pressure reduced towards control values and patients' colonic pressure response to a meal returned; HAPCs were observed in all controls, but in only 3 patients before and 2 patients after surgery; 3 patients had prolonged colonic transit before and 8 after rectopexy. The authors concluded that patients with rectal prolapse have abnormal colonic motility associated with reduced HAPC activity. Rectopexy reduced colonic pressure; but failed to restore HAPCs, reduce constipation or improve colonic transit.

van den Berg and co-workers (2006) defined the predictive value of colonic manometry and contrast enema before cecostomy placement in children with defecation disorders. Medical records, contrast enema, and colonic manometry studies were reviewed for 32 children with defecation disorders who underwent cecostomy placement between 1999 and 2004. Diagnoses included idiopathic constipation (n = 13), Hirschsprung's disease (n = 2), cerebral palsy (n = 1), imperforate anus (n = 6), spinal abnormality (n = 6), and anal with spinal abnormality (n = 4). Contrast enemas were evaluated for the presence of anatomic abnormalities and the degree of colonic dilatation. Colonic manometry was considered normal when HAPCs occurred from proximal to distal colon. Clinical success was defined as normal defecation frequency with no or occasional fecal incontinence (FI). Colonic manometry was carried out on 32 and contrast enema on 24 patients before cecostomy. At follow-up, 25 patients (78 %) fulfilled the success criteria. Absence of HAPCs throughout the colon was related to unsuccessful outcome (p = 0.03). Colonic response with normal HAPCs after bisacodyl administration was predictive of success (p = 0.03). Presence of colonic dilatation was not associated with colonic dysmotility. The authors concluded that colonic manometry was helpful in predicting the outcome after cecostomy. Patients with generalized colonic dysmotility were less likely to benefit from use of antegrade enemas via cecostomy. Normal colonic response to bisacodyl predicted favorable outcome.

Mugie and colleagues (2013) noted that in adults, colonic manometry and colonic scintigraphy are both valuable studies in discriminating normal and abnormal colonic motility. These researchers compared the diagnostic yield and tolerability of colonic manometry and colonic scintigraphy in children with severe constipation. A total of 26 children (mean age of 11.4 years, 77 % boys) who had received colonic manometry and colonic scintigraphy as part of a colonic motility evaluation were included. Manometry was performed as per department protocol. After swallowing a methacrylate-coated capsule containing indium-111, images were taken at 4, 24, and 48 hours, and geometric centers were calculated. Results of both tests were categorized in 3 groups: normal, abnormal function in the distal part of the colon, and colonic inertia. Cohen κ was used for the level of agreement. Patients and parents completed a questionnaire regarding their experience. Colonic scintigraphy showed normal transit time in 20 %, delay in the distal colon in 48 %, and colonic inertia in 32 % of patients. Colonic manometry was normal in 40 %, abnormal in the distal colon in 40 %, and colonic inertia was diagnosed in 20 %; the κ score was 0.34. All 5 patients with colonic inertia during manometry had a similar result by scintigraphy; 88 % of patients preferred scintigraphy over manometry and 28 % of parents preferred colonic manometry over scintigraphy. The authors concluded that colonic manometry and colonic scintigraphy had a fair agreement regarding the categorization of constipation; scintigraphy was well-tolerated in pediatric patients and may be a useful tool in the evaluation of children with severe constipation.

Liem and associates (2014) stated that colonic manometry is used in evaluating children with defecation disorders unresponsive to conventional treatment. The most commonly reported protocol in pediatrics consists of a study that lasts approximately 4 hours. Given the wide physiological variations in colonic motility throughout the day, longer observation may detect clinically relevant information. These researchers compared prolonged colonic manometry studies in children referred for colonic manometry with the more traditional short water-perfused technology. Colonic manometry studies of 19 children (8 boys, mean age of 9.4 ± 0.9, range of 3.9 to 16.3) with severe defecation disorders were analyzed. First, a "standard test" was performed with at least 1-hour fasting, 1-hour post-prandial, and 1-hour post-bisacodyl provocation recording. Afterwards, recordings continued until the next day. In 2 of the 19 children, prolonged recording provided extra information. In 1 patient with functional non-retentive FI who demonstrated no abnormalities in the short recording, 2 long clusters of HAPCs were noted in the prolonged study, possibly contributing to the FI. In another patient evaluated after failing use of antegrade enemas through a cecostomy, short recordings showed colonic activity only in the most proximal part of the colon, whereas the prolonged study showed normal motility over a larger portion of the colon. The authors concluded that prolonged colonic measurement provided more information regarding colonic motor function and allowed detection of motor events missed by the standard shorter manometry study.

El-Chammas and colleagues (2014) noted that colon manometry is usually performed using the 8-pressure sensor water-perfused manometry system. High-resolution manometry (HRM), using closely spaced solid-state pressure recording sensors, provided more detailed information of gut luminal pressure changes, and, by displaying the HRM data as a pressure topography plot (PTP), helps with data interpretation. These investigators compared the colon and rectal luminal pressure data obtained using 8 pressure sensors and displayed as conventional line plot (CLP) with data obtained using a custom-made solid state manometry catheter with 36 pressure recording sensors and displayed as PTP. They evaluated colon manometry patterns during fasting, response to meal, and bisacodyl stimulation in 10 patients with constipation and stool expulsion disorders. Data from 8 pressure sensors were displayed as CLP and data from 36 pressure sensors as PTP; 2 gastroenterologists independently interpreted these studies. They calculated variability in interpreting colon, rectal, and anal manometry data. Inter-mode, inter-observer, and intra-observer reliability were good-to-excellent for recognizing colon contraction patterns when data were displayed as PTP compared with when displayed as CLP, whereas the reliability for recognizing anal contractions were poor-to-excellent. The authors concluded that colonic and anal manometry patterns were easily recognized when HRM data were expressed as PTP. Obtaining information of colonic luminal pressure changes with rectum and anal pressure changes using HRM could aid in better understanding the pathophysiology of pediatric constipation and stool expulsion disorders.

Rodriguez and associates (2017) stated that over the last few years, the study of the colon and anorectal function has experienced great technical advances that have facilitated the performance of the tests and have allowed a more detailed characterization of reflexes and motor patterns. As a result, researchers have achieved a much better understanding of the pathophysiology of children with defecation problems. Anorectal and colonic manometry are now commonly used in all major pediatric referral centers as diagnostic tools and to guide the management of children with intractable constipation and fecal incontinence, especially when a surgical intervention is being considered. The authors highlighted some of the recent advances in pediatric colon and anorectal motility testing including indications and preparation for the studies, and how to perform and interpret the tests. This update has been endorsed by the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN).

Surjanhata and co-workers (2018) noted that chronic constipation may be categorized as normal transit (NTC), slow transit (STC), or outlet obstruction. Colonic wake response is a relative increase in colonic motility upon awakening. Colonic manometry studies have demonstrated attenuated wake response in STC. These researchers evaluated wake response among healthy (H), NTC, and STC patients using wireless motility capsule (WMC). They carried out a retrospective study of WMC data from a multi-center clinical trial and a tertiary gastroenterology clinic. WMC motility parameters of contraction frequency (Ct) and area under the contraction curve (AUC) were analyzed in 20-min windows 1-hour before and after awakening. T-tests compared parameters between H, NTC, and STC. Linear regression analysis was performed to determine if outlet obstruction confounded data. A receiver operating characteristic curve demonstrated optimal Ct cut-offs to define blunted wake response. A total of 62 H, 53 NTC and 75 STC subjects were analyzed. At 20, 40, and 60 mins after awakening, STC subjects had significantly lower mean Ct when compared to H (p < 0.001) and NTC (p < 0.01). Linear regression demonstrated that outlet obstruction was not associated with a decreased wake response (β = 3.94, (CI: -3.12 to 1.00), p = 0.27). Defined at the Ct threshold of 64 at 20-min post-wake, blunted wake response sensitivity was 84 % and specificity was 32 % for chronic constipation. The authors concluded that findings of an impaired wake response in subjects with STC and not NTC added further evidence to neuronal dysfunction as an etiology of STC, and identified a possible temporal target for pharmacologic intervention.

Magnetic Resonance Imaging Capsule Marker Methods for Measurement of Whole Gut Transit in Functional Gastro-Intestinal Disorders

Sharif and colleagues (2019) noted that functional gastro-intestinal disorders (FGID) are common conditions in children and adults, often associated with abnormalities of whole gut transit. At present, transit tests can be performed using several imaging methods, including tracking of radiopaque markers, gamma scintigraphy with the use of radioisotopes, magnetic tracking methods, tracking of movement of wireless motility capsules, and emerging magnetic resonance imaging (MRI) approaches. Whole gut transit time can be measured with MRI using capsule markers filled with water or a contrast agent, such as gadolinium. In a systematic review, these investigators examined recent literature on diagnostic imaging techniques used to investigate whole gut transit in FGIDs. The different techniques were described briefly, with particular emphasis on contemporary literature and new developments, especially in the field of MRI. The authors concluded that emerging MRI capsule marker methods are promising new tools to study whole gut transit in FGIDs. These researchers stated that one can expect most of the future GI transit imaging developments to come from MRI. The technological challenges of automated methods of data processing will be overcome with improved algorithms and machine learning.

Furthermore, UpToDate reviews on “Chronic abdominal pain in children and adolescents: Approach to the evaluation” (Sharif et al, 2020), “Functional dyspepsia in adults” (Longstreth and Lacy, 2020) and “Functional abdominal pain in children and adolescents: Management in primary care” (Chacko and Chiou, 2020) do not mention MRI capsule marker as a management option.

High-Resolution Impedance Manometry for the Diagnosis and Classification of Ineffective Esophageal Motility Disorder

Carlson and colleagues (2017) noted that high-resolution impedance manometry (HRIM) allows evaluation of esophageal bolus retention, flow, and pressurization.  These researchers carried out a collaborative analysis of HRIM metrics to examine patients with non-obstructive dysphagia.  A total of 14 asymptomatic controls (58 % women; age of 20 to 50 years) and 41 patients (63 % women; age of 24 to 82 years), 18 evaluated for dysphagia and 23 for reflux (non-dysphagia patients), with esophageal motility diagnoses of normal motility or ineffective esophageal motility, were evaluated with HRIM and a global dysphagia symptom score (Brief Esophageal Dysphagia Questionnaire).  HRIM was analyzed to examine Chicago Classification metrics, automated pressure-flow metrics, the esophageal impedance integral (EII) ratio, and the bolus flow time (BFT).  Significant symptom-metric correlations were detected only with basal EGJ pressure, EII ratio, and BFT.  The EII ratio, BFT, and impedance ratio differed between controls and dysphagia patients, while the EII ratio in the upright position was the only measure that differentiated dysphagia from non-dysphagia patients.  The authors concluded that the EII ratio and BFT appeared to offer an improved diagnostic evaluation in patients with non-obstructive dysphagia without a major esophageal motility disorder.  Bolus retention as measured with the EII ratio appeared to carry the strongest association with dysphagia; thus, it may aid in the characterization of symptomatic patients with otherwise normal manometry.  These researchers stated that future prospective and outcome studies are needed to demonstrate the benefits of these HRIM techniques to clinical practice; and may offer further insight into esophageal symptom generation.

The authors stated that in addition to the small sample size, this study was limited by its potential generalizability to clinical practice.  The methods require both HRIM, which can be expensive to obtain and maintain, and customized research software programs not yet available for wide-spread use.  Therefore, future implementation of these metrics into commercially available software packages would help to expand the use of HRIM to general clinical practice and increase the evidence base that is needed to underpin these methods.

Chugh and co-workers (2019) stated that ineffective esophageal motility (IEM) is defined as a distal contractile integral of less than 450 mmHg/s/cm in at least 50 % of 10 liquid swallows on high-resolution esophageal manometry (HREM).  Whether this latest definition correlates with degree of symptoms has not been studied.  In this study, patients presenting for HREM prospectively rated their symptoms using the Eckardt score.  Topography plots were retrospectively reviewed and classified according to the latest Chicago Classification.  Patients with non-obstructive dysphagia and an Eckardt score of at least 1 were included.  Patients with major motility disorders were excluded.  Scores between patients with IEM (group A) and patients with normal classification (group B) were compared using 2-tailed t-tests.  Spearman's correlation coefficient was calculated to determine correlation between symptoms and percent bolus clearance.  A total of 241 patients were screened; 33 patients met criteria for group A and 44 patients for group B.  There was no difference between the 2 groups in mean symptom severity for dysphagia (1.63 versus 1.61, p = 0.89), chest pain (0.67 versus 0.75, p = 0.64), regurgitation (1.06 versus 0.85, p = 0.32), or weight loss (0.85 versus 0.49, p = 0.11).  The percent bolus clearance was significantly lower in group A (46.5 % versus 76.7 %, p > 0.01).  There was a moderate inverse correlation between dysphagia and percent bolus clearance (R = - 0.37) in group A, but none in group B (R = 0.09).  The authors concluded that the classification of IEM did not discriminate from normal studies for symptom severity in this cohort; however, patients with IEM did have an inverse correlation between dysphagia score and bolus clearance, but those without IEM did not.  These researchers stated that adding impedance information to the motor pattern classification should be considered in the symptom assessment in minor motility disorders.

Gyawali et al (2019) stated that IEM is a heterogenous minor motility disorder diagnosed when greater than or equal to 50 % ineffective peristaltic sequences (distal contractile integral of less than 450 mm Hg cm s) co-exist with normal lower esophageal sphincter relaxation (integrated relaxation pressure less than upper limit of normal) on esophageal high-resolution manometry (HRM).  Ineffective esophageal motility is not consistently related to disease states or symptoms and may be observed in asymptomatic healthy individuals.

In a case-control study, Wu and associates (2020) examined the clinical significance of distal contractile integral-to- EII ratio (DCIIR) in IEM adult patients.  These investigators recruited 101 patients with IEM (age of 48.38 ± 1.58 years) and 42 matched healthy volunteers (age of 44.28 ± 1.85 years).  All subjects underwent esophageal HRIM from October 2014 to May 2018.  The diagnosis of IEM was based on the Chicago Classification version 3.0.  The EII, EII ratio, and DCIIR were analyzed by matlab software.  The EII, EII ratio, and DCIIR calculated at an impedance threshold of 1,500 Ω (EII1500, EII ratio1500, and DCIIR1500, respectively) were significantly lower in the IEM group than in healthy controls (p < 0.0001, p < 0.0001, and p < 0.0001, respectively).  Receiver operating characteristic analysis showed that DCIIR1500 of less than 0.008 mmHg/Ω, EII1500 of greater than 71 000 Ω.s.cm, and EII ratio1500 of greater than 0.43 were all predictive of IEM.  Only DCIIR1500 of less than 0.008 mmHg/Ω remained significant in diagnosing IEM in the multi-variate logistic regression analysis (OR = 72.13, p < 0.001).  The DCIIR1500 was negatively correlated with Eckardt score and the Reflux Disease Questionnaire (correlation coefficient = -0.2844 and -0.3136; p = 0.0006 and 0.0002, respectively).  Receiver operating characteristic analysis further showed that a DCIIR1500 cut-off of 0.002 mmHg/Ω achieved the best differentiation between the IEM-alternans and IEM-Persistens subtypes among IEM patients (p < 0.001).  The authors concluded that the novel pressure-impedance parameter of HRIM, DCIIR1500, may assist in the diagnosis and classification of IEM and correlated with clinical symptoms. 

An UpToDate review on “Approach to the evaluation of dysphagia in adults” (Fass, 2021) states that "Esophageal manometry should be performed in patients with dysphagia in whom upper endoscopy is unrevealing and/or an esophageal motility disorder is suspected. Although certain motility disorders (eg, achalasia) can be strongly suspected based upon their characteristic radiographic appearance when in advanced stages, confirmation with an esophageal manometry study is required to establish the diagnosis. The review states that “Ineffective esophageal motility: By high-resolution esophageal manometry, ineffective motility is defined as 50 to 90 % of the liquid swallows being weak or failed.  The manometric diagnosis of ineffective esophageal motility does not always correlate with symptoms or impaired esophageal function.  In one study, only 30 % of patients with ineffective esophageal motility reported dysphagia.  Moreover, studies using esophageal intraluminal impedance testing have shown that up to 68 % of liquid and 59 % of viscous swallows in such patients showed normal bolus transit”. 

Guidelines on assessment of uninvestigated esophageal dysphagia from the Canadian Association of Gastroenterology (Liu, et al., 2018) recommend esophageal manometry for diagnosis of esophageal motility disorders, and high-resolution was recommended over conventional manometry. The guidelines state that patients with symptoms of esophageal dysphagia should be assessed by history and physical examination, followed by endoscopy to identify structural and inflammatory lesions. If these are ruled out, then manometry is recommended for the diagnosis of esophageal dysmotility. 

1. high-resolution manometry over standard manometry in the investigation of dysphagia and, in particular, in characterizing achalasia,
2. esophageal manometry prior to antireflux surgery,
3. pH/impedance monitoring in patients with reflux symptoms not responding to high dose proton pump inhibitors, and
4. pH monitoring in all patients with reflux symptoms responsive to proton pump inhibitors in whom surgery is planned, but combined pH/impedance monitoring in those not responsive to proton pump inhibitors in whom surgery is planned.

Guidelines from the American College of Gastroenterology on esophageal physiological testing (Gyawali et al, 2020) recommend that patients with obstructive esophageal symptoms without a mechanical cause undergo high-resolution esophageal manometry for the evaluation for esophageal motility disorders (conditional recommendation, very low quality of evidence). The guidelines recommend high-resolution manometry over conventional line tracing manometry for the diagnosis of esophageal motility disorders in patients with obstructive esophageal symptoms (strong recommendation, moderate quality of evidence).  The guidelines recommend high-resolution impedance manometry with postprandial monitoring be used to confirm the diagnosis of rumination if clinically necessary in patients with esophageal symptoms suspicious for rumination syndrome (conditional recommendation, low quality of evidence).  The guidelines also note that esophageal high-resolution manometry complements the diagnostic evaluation of chest pain not responsive to PPI therapy.

Post-Operative Anorectal Manometry in Children with Hirschsprung Disease

Guidelines on the management of postoperative obstructive symptoms in children with Hirschsprung disease from the American Pediatric Surgical Association (Langer, et al., 2017) state that anorectal manometry may be useful in identifying pelvic dyssynergia if the child does not have a mechanical obstruction, the rectal biopsy and motility investigations are normal, and there has been no response to botulinum toxin.

Yates et al (2021) stated that there is wide variation in the clinical use of diagnostic tools for children with chronic constipation and functional/structural FI (CCFSFI).  Anorectal manometry (ARM) is a well-recognized technique to examine the function of the anorectum.  These researchers carried out an up-to-date review on ARM in pediatric patients with CCFSFI, with specific focus on the indication of use and protocol.  They performed a systematic search for empirical studies using ARM with a pediatric sample.  A keyword search of literature published in English before July 2018 was conducted and updated to October 2019.  Data on demographics, clinical information, study aims, ARM parameters and use of sedation/anesthesia were collected.  A total of 227 studies were included in this systematic review.  The age of study participants at the time of ARM ranged from birth to 18 years.  ARM was most commonly used in patients with organic conditions (65 %) compared to functional constipation (41 %).  In 48 % [108/227] of the studies, ARM was performed awake.  The ARM parameters most frequently assessed were the recto-anal inhibitory reflex, which was evaluated in 198/227 studies (87 %) and the anal resting pressure [166/227 studies (73 %)].  The authors concluded that this systematic review has highlighted the vast variation of ARM use within pediatrics and the need to strive toward standardization and use of consensus guidelines.  These researchers anticipated this would further advance the understanding of the pathophysiological mechanisms involved in children with defecation disorders.  Hirschsprung disease (HD) is one of the key words in this study.

Evans-Barns et al (2022) noted that HD is commonly encountered by pediatric surgeons.  Despite advances in the surgical management, these children may experience symptoms of bowel dysfunction throughout adulthood; ARM may be used to assess post-operative anorectal structure and function.  In a systematic review, these researchers examined the literature pertaining to post-operative findings of ARM in children with HD.  They synthesized the available data regarding anorectal motility patterns in children following repair of HD; and examined the reported ARM protocols.  These investigators carried out a systematic review of 4 databases: Embase, Medline, the Cochrane Library, and PubMed; the systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline.  Studies reporting results of post-operative ARM in children with HD were evaluated for inclusion.  A total of 23 studies met inclusion criteria, with a combined cohort of 939 patients.  Post-operative ARM results were reported for 682 children.  The majority of included studies were assessed as "poor quality".  Disparate manometry protocols, heterogeneous cohorts, and lack of standardized outcome assessments introduced a risk of outcome reporting bias, limited the comparability of results, and impeded clinical translation of findings.  The authors concluded that this systematic review demonstrated the lack of high-quality evidence underlying the current understanding of post-operative anorectal motility in children with HD.  There was little consistency in reported manometry outcomes between studies.  In future work, emphasis must be placed on the application of standardized manometry protocols, cohort reporting, and patient outcome assessments.

Post-Operative Colonic Manometry in Children with Hirschsprung Disease

Guidelines on the management of postoperative obstructive symptoms in children with Hirschsprung disease from the American Pediatric Surgical Association (Langer, et al., 2017) recommend colonic manometry if colonic motility studies are abnormal, so that the location and nature of the dysmotility can be more accurately determined.

Evans-Barns et al (2021) stated that a significant proportion of children experience bowel dysfunction (including constipation and FI) following surgical repair of HD.  Persistent symptoms are thought to relate to underlying colonic and/or anorectal dysmotility.  Manometry may be used to examine the gastro-intestinal (GI) motility patterns of this population.  These investigators examined the colonic manometry equipment and protocols used in the assessment of the post-operative HD population and summarized the available evidence regarding colonic motility patterns in children with HD following surgical repair.  These researchers performed a systematic review of the Cochrane Library, Embase, Medline, and PubMed databases (January 1, 1980 and March 9, 2020).  Data were extracted independently by 2 authors.  This systematic review was conducted in accordance with PRISMA guidelines.  Studies reporting the post-operative assessment of children with HD using colonic manometry were considered for inclusion.  A total of 5 studies met selection criteria, providing a combined total of 496 children.  Of these, 184 children with repaired HD underwent colonic manometry.  Studies assessed heterogeneous populations, used variable manometry equipment and protocols, and reported limited baseline symptom characteristics; therefore, restricting comparability.  All studies used low-resolution colonic manometry.  The authors concluded that this systematic review highlighted the paucity of evidence informing the understanding of colonic dysmotility in the post-operative HD cohort.  These researchers stated that current literature is limited by variable methodologies, heterogeneous cohorts, and the lack of high-resolution manometry.

Pharyngeal High-Resolution Manometry with Impedance for the Evaluation of Dysphagia

In a systematic review, Winiker et al (2019) examined the methodology documented in studies using high-resolution pharyngeal manometry (HRM) with and without impedance technology (HRIM) in adult populations.  A total of 4 electronic databases CINAHL, Embase, Medline, and Cochrane Library were searched up to, and including March 2017.  Studies reporting pharyngeal HRM/HRIM for swallowing and/or phonatory assessment, published in peer-reviewed journals in English, German, or Spanish were assessed for the inclusion criteria.  Of the selected studies, methodological aspects of data acquisition and analysis were extracted.  Publications were graded based on their level of evidence and quality of methodological aspects was assessed.  A total of 62 articles were identified eligible, from which 50 studies reported the use of HRM and 12 studies used HRIM.  Of all included manuscripts, the majority used the ManoScan system (64.5 %), a catheter diameter of 4.2 mm was most prevalently documented (30.6 %).  Most publications reported the application of topical anesthesia (53.2 %).  For data analysis in studies using HRM, software intrinsic to the recording system was reported most frequently (56 %).  A minority of the studies using HRM provided data about measurement reliability (10 %).  This was higher for studies using HRIM (50 %).  The authors concluded that considerable methodological variability exists regarding data acquisition and analysis in published studies using HRM/HRIM.  Lacking reports of methodology made study replications difficult and reduced the comparability across studies.  These researchers stated that further investigations regarding the impact of individual methodological aspects on study outcomes are needed for the development of methodological recommendations.

Omari et al (2020) noted that HRM has traditionally been used in gastroenterology diagnostic clinical and research applications.  Recently, it is also finding new and important applications in speech pathology and laryngology practices.  A High-Resolution Pharyngeal Manometry International Working Group was formed as a grass roots effort to establish a consensus on methodology, protocol, and outcome metrics for high-resolution pharyngeal manometry (HRPM) with consideration of impedance as an adjunct modality.  The Working Group undertook 3 tasks.  First, survey what experts were currently doing in their clinical and/or research practice.  Second, perform a review of the literature underpinning the value of particular HRPM metrics for understanding swallowing physiology and pathophysiology.  Third, establish a core outcomes set of HRPM metrics via a Delphi consensus process.  Expert survey results were used to create a recommended HRPM protocol addressing system configuration, catheter insertion, and bolus administration.  A total of 92 articles were included in the final literature review resulting in categorization of 22 HRPM-impedance metrics into 3 classes: pharyngeal lumen occlusive pressures; hypopharyngeal intrabolus pressures; and upper esophageal sphincter (UES) function.  A stable Delphi consensus was achieved for 8 HRPM-Impedance metrics: pharyngeal contractile integral (CI), velopharyngeal CI, hypopharyngeal CI, hypopharyngeal pressure at nadir impedance, UES integrated relaxation pressure, relaxation time, and maximum admittance.  The authors concluded that while some important unanswered questions remain, their work represented the 1st step in standardization of high-resolution pharyngeal manometry acquisition, measurement, and reporting.  This could potentially inform future proposals for an HRPM-based classification system specifically for pharyngeal swallowing disorders.

Rogus-Pulia et al (2020) evaluated experienced clinicians' perceptions of benefits and drawbacks to the clinical adoption of HRM.  These investigators focused on the professional and institutional factors that influence the clinical adoption of pharyngeal HRM by speech-language pathologists (SLPs).  Two surveys (closed- and open-ended questions) and a series of focus groups were completed with SLP members of both the American Speech-Language-Hearing Association (ASHA) and the Dysphagia Research Society (DRS).  Transcripts were inductively coded for emergent themes.  A total of 13 SLPs were recruited to attend focus group sessions at the ASHA; 87 SLPs responded to the DRS open-set response survey.  Two additional focus groups of 11 SLPs were convened at the DRS meeting.  Conventional content analysis revealed overall SLP enthusiasm for the clinical use of HRM, with some concerns regarding the technology adoption process.  The following themes related to the professional and institutional factors influencing clinical adoption were identified: scope of practice; access; clinical workflow; and reimbursement.  The authors concluded that these findings served to elucidate the most salient factors relating to the clinical adoption of pharyngeal HRM into routine speech-language pathology clinical practice.  Moreover, these researchers stated that while enthusiasm exists, a variety of systems-level issues must be addressed to support this process.

Diver and Regan (2022) stated that there has been a recent shift towards proactive dysphagia intervention in motor neuron disease (MND) to maintain physiological reserve.  Pharyngeal high-resolution manometry (PHRM) can quantify swallowing pathophysiology to inform and evaluate proactive dysphagia intervention.  These investigators examined the current use of PHRM as a dysphagia evaluation in adults with MND.  A scoping review based on the Joanna Briggs Framework was completed.  A total of 4 electronic databases (PubMed, Embase, CINAHL and Web of Science core) were searched (from inception to March 2021) by 2 independent researchers.  Data were analyzed according to PHRM protocol and analysis methods and the feasibility of same; swallow biomechanics data; and dysphagia intervention effects as measured by PHRM.  A total of 6 studies with 78 patients with MND (PwMND) were included.  There was considerable variation in PHRM protocol and analysis methods – 5 studies reported a 100 % completion rate and 3 studies reported no adverse events (AEs).  Swallow biomechanics data were reported across all studies.  The effects of sensory stimulation, increased bolus consistency, effortful swallow and cricopharyngeal myotomy were evaluated using PHRM with 20 PwMND across 4 studies with varying effects.  These researchers stated that the literature on the use of PHRM in PwMND was limited.  Variability in PHRM methods restricted comparison of metrics.  The authors concluded that PHRM appeared to be a feasible tool for PwMND; PHRM could provide novel swallow physiology data in PwMND and quantify discrete effects of compensatory and surgical dysphagia interventions not detectable by videofluoroscopy or FEES.  Moreover, these researchers stated that further investigation on the effects of proactive dysphagia intervention as measured by PHRM is needed.

Heslin and Regan (2022) noted that evidence base to support the use of the effortful swallow in clinical populations with dysphagia is currently lacking.  These researchers examined the effects of effortful swallowing on pharyngeal swallowing biomechanics in adults with dysphagia using PHRM.  ManoScan HRM equipment with a 4.2-mm pressure catheter was employed.  Subjects completed duplicate 10-ml baseline and 10-ml effortful liquid (IDDSI Level 0) swallows in randomised order.  PHRM data were analyzed using a semi-automated online platform (www.swallowgateway.com).  A total of 15 adults (8 men; age range of 45 to 86 years) with mixed etiology dysphagia (Functional Oral Intake Scale Level 2 to 5) were included.  Median pharyngeal contractile (156.81 mmHg cm s; inter-quartile-range [IQR] 80.62) increased significantly (213.50 mmHg cm s; IQR 117.2) during effortful swallowing.  Significant increases were also observed in velopharyngeal pressure, meso-pharyngeal pressure, hypopharyngeal pressure as well as upper esophageal sphincter (UES) relaxation duration.  UES integrated relaxation pressure (IRP) was not significantly altered with effortful swallowing.  The authors concluded that effortful swallowing induced significant biomechanical changes to swallow in adults with dysphagia.  Increases in global pharyngeal rigor, tongue base pressure and UES opening duration were captured by PHRM during effortful swallowing.  Moreover, these researchers stated that further investigation in larger homogeneous clinical populations is needed to verify the physiological effects of this frequently employed intervention.

Omari et al (2023) stated that oro-pharyngeal pathophysiology, including upper esophageal sphincter (UES) and pharyngeal disorders, can be examined by pharyngeal high-resolution manometry impedance (P-HRM-I).  These researchers aimed to establish methodology to diagnose disorders by means of P-HRM-I, hypothesizing that the objective measures could be used to diagnose disordered deglutition evidenced by greater aspiration scores.  Patients (n = 509, age of 18 to 91 years) were compared to controls (n = 120, age of 20 to 94 years).  Variables measuring UES relaxation, UES opening extent, intra-bolus pressure, and pharyngeal contractile strength were derived for 10-ml liquid swallows.  Three associated pharyngeal pressurization patterns, which may be indicative of obstructed flow, were characterized: pan-pressurization (Type 1), distal compartmentalized pressurization (Type 2), and transient pressurization (Type 3).  Deglutitive aspiration was determined from video fluoroscopy.  UES relaxation pressure was best able to differentiate patients from controls (T 6.528, p < 0.0001).  Patients with abnormal relaxation pressure (greater than 8 mmHg) more frequently exhibited pharyngeal pressurization patterns and had adjunct evidence of reduced luminal distensibility (high intra-bolus pressure and/or reduced UES opening).  Utilizing this information, a diagnostic scheme was devised identifying 138 patients with UES disorder.  A further 96 patients without evidence of UES disorder had abnormally weak pharyngeal pressures, confirming propulsive disorder.  Among a sub-sample of 320 patients undergoing video fluoroscopy, those with pharyngeal pressurizations and adjunct evidence of reduced UES relaxation and/or distensibility had higher aspiration scores (Chi-square 60.169, p < 0.0001).  The authors concluded that P-HRM-I could provide evidence for UES disorder based on pharyngeal pressurization patterns and abnormal findings for UES relaxation pressure, UES opening, and intra-bolus pressure; however, measuring pharyngeal contractility requires further optimization.

Walters et al (2024) stated that the use of HRPM in the evaluation of pharyngeal dysphagia has been increasing; however, standardization of its use has lagged behind.  Without standardization using normative values, it is difficult for clinicians to adopt this emerging technology into meaningful use.  In a systematic review, these investigators compared the published normative values for common HRPM metrics to aid in establishing consensus reference values.  They carried out a systematic review on prospective and retrospective studies that included HRPM metrics, defined by an international working group consensus, in healthy adult populations.  Data on the following variables were extracted when available: contractile integrals of the pharynx (PhCI), velo-pharynx, meso-pharynx, and hypo-pharynx, as well as the UES integrated relaxation pressure (IRP), relaxation time (RT), maximum admittance, and hypopharyngeal intra-bolus pressure.  A total of 30 studies were included.  Significant variation existed in the technique and equipment used to carry out procedures between the different studies.  Lower PhCIs and UES IRPs were observed in younger compared to older individuals.  Higher UES RTs were found in individuals in the upright position compared to the supine position and in those using larger boluses sizes or smaller catheters.  The authors concluded that due to the wide variety of protocols, catheter configurations, manufacturers, and software used in the existing literature, it is difficult to formulate consensus on HPRM normative values using pooled data.  These researchers stated that prospective studies adhering to standardized HRPM protocols for specific catheter configurations and manufacturers with larger cohorts of normal individuals are needed to establish proper reference values for HRPM metrics.

Furthermore, UpToDate reviews on “Approach to the evaluation of dysphagia in adults” (Fass, 2024), and “Oropharyngeal dysphagia: Clinical features, diagnosis, and management” (Lembo, 2024) do not mention pharyngeal high-resolution manometry as a management option.

References