Clinical utility of a functional lumen imaging probe in management of dysphagia following head and neck cancer therapies.

Background and aims Chemoradiotherapy for head and neck cancer (HNC) with/without laryngectomy commonly causes dysphagia. Pharyngoesophageal junction (PEJ) stricturing is an important contributor. We aimed to validate a functional lumen imaging probe (the EndoFLIP system) as a tool for quantitating pretreatment PEJ distensibility and treatment-related changes in HNC survivors with dysphagia and to evaluate the diagnostic accuracy of EndoFLIP-derived distensibility in detecting PEJ strictures. Methods We studied 34 consecutive HNC survivors with long-term (> 12 months) dysphagia who underwent endoscopic dilation for suspected strictures. Twenty non-dysphagic patients undergoing routine endoscopy served as controls. PEJ distensibility was measured at endoscopy with the EndoFLIP system pre- and post-dilation. PEJ stricture was defined as the presence of a mucosal tear post-dilation. Results PEJ stricture was confirmed in 22/34 HNC patients (65 %). During distension up to 60 mmHg, the mean EndoFLIP-derived narrowest cross-sectional area (nCSA) in HNC patients with strictures, without strictures, and in controls were 58 mm2 (95 % confidence interval [CI] 22 to 118), 195 mm2 (95 %CI 129 to 334), and 227 mm2 (95 %CI 168 to 316), respectively. A cutoff of 114 mm2 for the nCSA at the PEJ had perfect diagnostic accuracy in detecting strictures (area under the receiver operating characteristic curve = 1). In patients with strictures, a single session of dilation increased the nCSA by 29 mm2 (95 %CI 20 to 37; P < 0.001). In patients with no strictures, dilation caused no change in the nCSA (mean difference 13 mm2 [95 %CI -4 to 30]; P = 0.13). Conclusions EndoFLIP is a highly accurate technique for the detection of PEJ strictures. EndoFLIP may complement conventional diagnostic tools in the detection of pharyngeal outflow obstruction.

Sacral Nerve Stimulation Fails to Offer Long-term Benefit in Patients With Slow-Transit Constipation.

BACKGROUND: Sacral nerve stimulation is proposed as a treatment for slow-transit constipation. However, in our randomized controlled trial we found no therapeutic benefit over sham stimulation. These patients have now been followed-up over a long-term period. OBJECTIVE: The purpose of this study was to assess the long-term efficacy of sacral nerve stimulation in patients with scintigraphically confirmed slow-transit constipation. DESIGN: This study was designed for long-term follow-up of patients after completion of a randomized controlled trial. SETTINGS: It was conducted at an academic tertiary public hospital in Sydney. PATIENTS: Adults with slow-transit constipation were included. MAIN OUTCOME MEASURES: At the 1- and 2-year postrandomized controlled trial, the primary treatment outcome measure was the proportion of patients who reported a feeling of complete evacuation on >2 days per week for ≥2 of 3 weeks during stool diary assessment. Secondary outcome was demonstration of improved colonic transit at 1 year. RESULTS: Fifty-three patients entered long-term follow-up, and 1 patient died. Patient dissatisfaction or serious adverse events resulted in 44 patients withdrawing from the study because of treatment failure by the end of the second year. At 1 and 2 years, 10 (OR = 18.8% (95% CI, 8.3% to 29.3%)) and 3 patients (OR = 5.7% (95% CI, -0.5% to 11.9%)) met the primary outcome measure. Colonic isotope retention at 72 hours did not differ between baseline (OR = 75.6% (95% CI, 65.7%-85.6%)) and 1-year follow-up (OR = 61.7% (95% CI, 47.8%-75.6%)). LIMITATIONS: This study only assessed patients with slow-transit constipation. CONCLUSIONS: In these patients with slow-transit constipation, sacral nerve stimulation was not an effective treatment.

Treatment efficacy of sacral nerve stimulation in slow transit constipation: a two-phase, double-blind randomized controlled crossover study.

OBJECTIVES: Sacral nerve stimulation (SNS) is a potential treatment for constipation refractory to standard therapies. However, there have been no randomized controlled studies examining its efficacy. In patients with slow transit constipation, we evaluated the efficacy of suprasensory and subsensory SNS compared with sham, in a prospective, 18-week randomized, double-blind, placebo-controlled, two-phase crossover study. The primary outcome measure was the proportion of patients who, on more than 2 days/week for at least 2 of 3 weeks, reported a bowel movement associated with a feeling of complete evacuation. METHODS: After 3 weeks of temporary peripheral nerve evaluation (PNE), all patients had permanent implantation and were randomized to subsensory/sham (3 weeks each) and then re-randomized to suprasensory/sham (3 weeks each) with a 2-week washout period between each arm. Daily stool dairies were kept, and quality of life (QoL; SF36) was measured at the end of each arm. RESULTS: Between November 2006 and March 2012, 234 constipated patients were assessed, of whom 59 were willing and deemed eligible to participate (4 male; median age 42 years). Of the 59 patients, 16 (28%) responded to PNE. Fifty-five patients went on to permanent SNS implantation. The proportion of patients satisfying the primary outcome measure did not differ between suprasensory (30%) and sham (21%) stimulations, nor between subsensory (25%) and sham (25%) stimulations. There were no significant changes in QoL scores. CONCLUSIONS: In patients with refractory slow transit constipation, SNS did not improve the frequency of complete bowel movements over the 3-week active period.

Efficacy and safety of pneumatic dilatation for achalasia in the treatment of post-myotomy symptom relapse.

OBJECTIVES: There is no consensus on how best to treat symptom recurrence following previous therapy with Heller myotomy. Our aim was to determine the safety and the short and long-term efficacy of pneumatic dilatation to treat symptomatic recurrence in patients previously treated with Heller myotomy for idiopathic achalasia. METHODS: We identified 27 eligible patients treated with pneumatic dilatation, for symptom recurrence following Heller myotomy as their initial or secondary treatment, from a prospectively acquired database of 450 patients with a diagnosis of achalasia seen between 1995 and 2010. Our treatment protocol involved sequential, graded pneumatic dilatations (30-35-40 mm) over a 2-6 week period until an initial therapeutic response was achieved. The subsequent relapse rate, defined as the need for any subsequent therapy, was determined. Relapsers were offered further pneumatic dilatation "on demand". A cross-sectional analysis was also performed using a validated achalasia severity questionnaire to determine the overall long-term remission rate. RESULTS: Of 27 eligible patients, 25 (93%) complied with the institutional dilatation protocol. The two drop-outs did so after the initial 30 mm dilatation and were deemed treatment failures. One additional patient did not respond despite protocol compliance. Therefore, 24 of 27 (89%) patients were responders on intention to treat analysis at 12 months, while the per protocol response rate was 24 of 25 (96%). Among the 24 responders 16, 25, and 42% relapsed at 2, 3 and 4 years, respectively. Overall long-term remission, with on demand dilatations as required, was 95% (median follow-up 30 months). There were no perforations in a total of 50 dilatations in 27 patients. CONCLUSIONS: In treating symptom recurrence, following prior Heller myotomy, pneumatic dilatation is safe and yields an excellent short-term response rate. Although the long-term relapse rate is substantial, subsequent on demand pneumatic dilatation in this population is highly effective with a long-term remission rate of 95%. These data also highlight the need to keep these patients under long-term review.

The impact of laxative use upon symptoms in patients with proven slow transit constipation.

BACKGROUND: Constipation severity is often defined by symptoms including feelings of complete evacuation, straining, stool frequency and consistency. These descriptors are mostly obtained in the absence of laxative use. For many constipated patients laxative usage is ubiquitous and long standing. Our aim was to determine the impact of laxative use upon the stereotypic constipation descriptors. METHODS: Patients with confirmed slow transit constipation completed 3-week stool diaries, detailing stool frequency and form, straining, laxative use and pain and bloating scores. Each diary day was classified as being under laxative affect (laxative affected days) or not (laxative unaffected days). Unconditional logistic regression was used to assess the affects of laxatives on constipation symptoms. RESULTS: Ninety four patients with scintigraphically confirmed slow transit constipation were enrolled in the study. These patients reported a stool frequency of 5.6 ± 4.3 bowel motions/week, only 21 patients reported <3 bowel motions/week. Similarly, 21 patients reported a predominant hard stool at defecation. The majority (90%) of patients reported regular straining. A regular feeling of complete evacuation was reported in just 7 patients. Daily pain and/or bloating were reported by 92% of patients. When compared with laxative unaffected days, on the laxative affected days patients had a higher stool frequency (OR 2.23; P <0.001) and were more likely to report loose stools (OR 1.64; P <0.009). Laxatives did not increase the number of bowel actions associated with a feeling of complete evacuation. Laxative use had no affect upon straining, pain or bloating scores CONCLUSIONS: The reporting of frequent and loose stools with abdominal pain and/or bloating is common in patients with slow transit constipation. While laxative use is a significant contributor to altering stool frequency and form, laxatives have no apparent affect on pain or bloating or upon a patients feeling of complete evacuation. These factors need to be taken into account when using constipation symptoms to define this population.

Cricopharyngeal peroral endoscopic myotomy improves oropharyngeal dysphagia in patients with Parkinson's disease.

Background and study aims Oropharyngeal dysphagia (OPD) is prevalent in patients with Parkinson's disease (PD). Upper esophageal sphincter (UES) dysfunction is an important pathophysiological factor for OPD in PD. The cricopharyngeus (CP) is the main component of UES. We assessed the preliminary efficacy of cricopharyngeal peroral endoscopic myotomy (C-POEM) as a treatment for dysphagia due to UES dysfunction in PD. Patients and methods Consecutive dysphagic PD patients with UES dysfunction underwent C-POEM. Swallow metrics derived using high-resolution pharyngeal impedance manometry (HRPIM) including raised UES integrated relaxation pressure (IRP), raised hypopharyngeal intrabolus pressure (IBP), reduced UES opening caliber and relaxation time defined UES dysfunction. Sydney Swallow Questionnaire (SSQ) and Swallowing Quality of Life Questionnaire (SWAL-QOL) at before and 1 month after C-POEM measured symptomatic improvement in swallow function. HRPIM was repeated at 1-month follow-up. Results C-POEM was performed without complications in all (n = 8) patients. At 1 month, there was an improvement in both the mean SSQ (from 621.5 to 341.8, mean difference -277.3, 95 %CI [-497.8, -56.7], P  = 0.02) and SWAL-QOL (from 54.9 to 68.3, mean difference 9.1, 95 %CI [0.7, 17.5], P  = 0.037) scores. Repeat HRPIM confirmed a decrease in both the mean UES IRP (13.7 mm Hg to 3.6 mm Hg, mean difference -10.1 mm Hg, 95 %CI [-16.3, -3.9], P  = 0.007) and the mean hypopharyngeal IBP (23.5 mm Hg to 10.4 mm Hg, mean difference -11.3 mm Hg, 95 %CI [-17.2, -5.4], P  = 0.003). Conclusions In dysphagic PD patients with UES dysfunction, C-POEM is feasible and enhances UES relaxation and reduces sphincteric resistance to flow during the swallow, thereby improving dysphagia symptoms.

Design of a high-sensor count fibre optic manometry catheter for in-vivo colonic diagnostics.

The design of a fibre Bragg grating based manometry catheter for in-vivo diagnostics in the human colon is presented. The design is based on a device initially developed for use in the oesophagus, but in this instance, longer sensing lengths and increased flexibility were required to facilitate colonoscopic placement of the device and to allow access to the convoluted regions of this complex organ. The catheter design adopted allows the number of sensing regions to be increased to cover extended lengths of the colon whilst maintaining high flexibility and the close axial spacing necessary to accurately record pertinent features of peristalsis. Catheters with 72 sensing regions with an axial spacing of 1 cm have been assembled and used in-vivo to record peristaltic contractions in the human colon over a 24hr period. The close axial spacing of the pressure sensors has, for the first time, identified the complex nature of propagating sequences in both antegrade (towards the anus) and retrograde (away from the anus) directions in the colon. The potential to miss propagating sequences at wider sensor spacings is discussed and the resultant need for close axial spacing of sensors is proposed.

Novel Therapeutic Strategy for Pharyngoesophageal Stricture following Total Laryngectomy.

Current therapeutic strategies for pharyngoesophageal stricture, while effective in the short term, are protracted and costly in the longer term. Conceptually, if a stricture can be dilated with minimal tissue injuries, the rate of fibrosis and the resultant stricture recurrence could be reduced. We evaluated a prototype computer-controlled syringe pump device programmed to distend a commercially available balloon dilator at variable rate, asserting incremental lumen distension pressures tailored to the resistive force encountered within the stricture. We completed 17 graded dilatation procedures among 4 total laryngectomy patients. All patients had a short-term response (1 month), with a mean decrement (improvement) in Sydney Swallow Questionnaire score of 448 (total score range, 0-1700; normal <234). The overall procedural tolerability and safety were encouraging; the only complication was the displacement of the voice prosthesis during 1 dilatation. From a technical viewpoint, the main challenge was to maintain the balloon in position during dilatation.

Esophageal Dysmotility in Patients following Total Laryngectomy.

Objectives Dysphagia is common in total laryngectomees, with some symptoms suggesting esophageal dysmotility. Tracheoesophageal (TE) phonation requires effective esophagopharyngeal air passage. Hence, esophageal dysmotility may affect deglutition or TE phonation. This study aimed to determine (1) the characteristics of esophageal dysmotility in laryngectomees, (2) whether clinical history is sensitive in detecting esophageal dysmotility, and (3) the relationship between esophageal dysmotility and TE prosthesis dysfunction. Study Design Multidisciplinary cross-sectional study. Setting Tertiary academic hospital. Subjects and Methods For 31 participants undergone total laryngectomy 1 to 12 years prior, clinical histories were taken by a gastroenterologist and a speech pathologist experienced in managing dysphagia. Esophageal high-resolution manometry was performed and analyzed using Chicago Classification v3.0. Results Interpretable manometric studies were obtained in 23 (1 normal manometry). Esophageal dysmotility patterns included achalasia, esophagogastric junction outflow obstruction, diffuse esophageal spasm, and other major (30%) and minor (50%) peristaltic disorders. The sensitivity of predicting any esophageal dysmotility was 28%, but it is noteworthy that patients with achalasia and diffuse esophageal spasm (DES) were predicted. Two of 4 participants with TE puncture leakage had poor esophageal clearance. Of 20 TE speakers, 12 had voice problems, no correlation between poor voice, and any dysmotility pattern. Conclusions Peristaltic and lower esophageal sphincter dysfunction are common in laryngectomees. Clinical history, while not predictive of minor motor abnormalities, predicted correctly cases with treatable spastic motor disorders. Dysmotility was not associated with poor phonation, although TE puncture leakage might be linked to poor esophageal clearance. Esophageal dysmotility should be considered in the laryngectomees with persisting dysphagia or leaking TE puncture.

Biomechanics of Pharyngeal Deglutitive Function following Total Laryngectomy.

OBJECTIVE: Postlaryngectomy, pharyngeal weakness, and pharyngoesophageal junction (PEJ) restriction are the candidate mechanisms of dysphagia. The aims were, in laryngectomees, whether (1) hypopharyngeal propulsion is reduced and/or PEJ resistance is increased, (2) dilatation improves dysphagia, and (3) whether symptomatic improvement correlates with reduced PEJ resistance. DESIGN: Multidisciplinary cross-sectional study. SETTING: Tertiary academic hospital. SUBJECTS AND METHODS: Swallow biomechanics were assessed in 30 laryngectomees. Patients were stratified into severe dysphagia (Sydney Swallow Questionnaire >500) and mild/nil dysphagia (Sydney Swallow Questionnaire ≤500). Average hypopharyngeal peak (contractile) pressure (hPP) and hypopharyngeal intrabolus pressure (hIBP) were measured from high-resolution manometry with concurrent videofluoroscopy based on barium swallows (2.5 and 10 mL). In consecutive 5 patients, measurements were repeated after dilatation. RESULTS: Dysphagia was reported by 87%, and 57% had severe and 43% had mild/nil dysphagia. hIBP increased with larger bolus volumes (P < .0001), while hPP stayed stable and PEJ diameter plateaued at 9 mm. Laryngectomees had lower hPP (110 ± 14 vs 170 ± 15 mm Hg; P = .0162) and higher hIBP (29 ± 5 vs 6 ± 5 mm Hg; P = .156) than controls. There were no differences in hPP between patient groups. However, hIBP was higher in severe than in mild/nil dysphagia (41 ± 10 vs 13 ± 3 mm Hg; P = .02). Predilation hIBP (R(2) = 0.97) and its decrement postdilatation (R(2) = 0.98) well predicted symptomatic improvement. CONCLUSIONS: PEJ resistance correlates better with dysphagia severity than peak pharyngeal pressure and is more sensitive to bolus sizes than PEJ diameter. Both baseline PEJ resistance and its decrement following dilatation are strong predictors of treatment outcome. PEJ resistance is vital to detect, as it is reversible and can predict the response to dilatation regimens.

Videofluoroscopic Swallow Examination Does Not Accurately Detect Cricopharyngeal Radiation Strictures.

Videofluoroscopy is the standard technique to evaluate dysphagia following radiotherapy for head and neck cancer (HNC). The accuracy of radiography in detecting strictures at the pharyngoesophageal junction is unknown. Our aim was to determine the diagnostic accuracy of videofluoroscopy in detecting strictures at the pharyngoesophageal junction prior to endoscopic dilatation in a consecutive series of HNC survivors with dysphagia. Presence of a stricture on videofluoroscopy was determined by 3 experienced blinded investigators and compared against a gold standard, defined as presence of a mucosal tear during endoscopic dilatation. In 10 of 33 patients, there was complete agreement among observers with respect to the presence or absence of a stricture. Overall, the concordance among observers in identification of strictures was very poor, with a kappa of 0.05 (P = .30). The diagnostic sensitivity and specificity of videofluoroscopy in detecting strictures was 0.76 and 0.58, respectively. Videofluoroscopy alone is inadequate to detect strictures in HNC survivors with dysphagia.

Acid sensitization of esophageal mucosal afferents: implication for symptom perception in patients across the gastroesophageal reflux disease spectrum.

BACKGROUND: Sensitization of esophageal chemoreceptors, either directly by intermittent acid exposure or indirectly through esophagitis-associated inflammatory mediators, is likely to be the mechanism underlying the perception of heartburn. AIMS: To compare basal esophageal sensitivity with electrical stimulation and acid, and to compare the degree of acid-induced sensitization in controls and in patient groups across the entire spectrum of gastroesophageal reflux disease: erosive oesophagitis (EO), nonerosive reflux disease (NERD), and functional heartburn (FH). METHODS: Esophageal sensory and pain thresholds to electrical stimulation were measured before, 30, and 60 minutes after an intraesophageal infusion of saline or HCl. Patients received a 30-minute infusion of 0.15 M HCl and controls were randomized to receive either HCl (n = 11) or saline (n = 10). After electrical sensory threshold testing, participants received another 30-minute infusion of HCl to determine whether sensitivity to acid is increased by prior acid exposure RESULTS: All patient groups had higher basal sensory thresholds than healthy controls (controls, 13 ± 1.4 mA; FH, 20 ± 5.1 mA; NERD, 21 ± 5.1 mA; EO, 23 ± 5.4 mA; P < 0.05). Acute esophageal acid exposure reduced sensory thresholds to electrical stimulation in FH and NERD patients (P < 0.05). The level of acid sensitivity during the first HCl infusion was comparable between all patient groups and controls. The secondary infusion caused increased discomfort in all participants (P < 0.01). This acid-induced sensitization to HCl was significantly elevated in the patient groups ( P < 0.05). CONCLUSIONS: (1) Esophageal acid infusion sensitizes it to subsequent electrical and chemical stimulation. (2) The acid-related sensitization is greater in gastroesophageal reflux disease than in controls and may influence in part symptom perception in this population. (3) Acid-related sensitization within the gastroesophageal reflux disease population is not dependant on mucosal inflammation.

Transabdominal electrical stimulation increases colonic propagating pressure waves in paediatric slow transit constipation.

BACKGROUND AND AIMS: In slow-transit constipation (STC) pancolonic manometry shows significantly reduced antegrade propagating sequences (PS) and no response to physiological stimuli. This study aimed to determine whether transcutaneous electrical stimulation using interferential current (IFC) applied to the abdomen increased colonic PS in STC children. METHODS: Eight children (8-18 years) with confirmed STC had 24-h colonic manometry using a water-perfused, 8-channel catheter with 7.5 cm sidehole distance introduced via appendix stomas. They then received 12 sessions (20 min/3× per week) of IFC stimulation (2 paraspinal and 2 abdominal electrodes), applied at a comfortable intensity (<40 mA, carrier frequency 4 kHz, varying beat frequency 80-150 Hz). Colonic manometry was repeated 2 (n=6) and 7 (n=2) months after IFC. RESULTS: IFC significantly increased frequency of total PS/24h (mean ± SEM, pre 78 ± 34 vs post 210 ± 62, p=0.008, n=7), antegrade PS/24h (43 ± 16 vs 112 ± 20, p=0.01) and high amplitude PS (HAPS/24h, 5 ± 2:10 ± 3, p=0.04), with amplitude, velocity, or propagating distance unchanged. There was increased activity on waking and 4/8 ceased using antegrade continence enemas. CONCLUSIONS AND INFERENCES: Transcutaneous IFC increased colonic PS frequency in STC children with effects lasting 2-7 months. IFC may provide a treatment for children with treatment-resistant STC.

Factor analysis identifies subgroups of constipation.

AIM: To determine whether distinct symptom groupings exist in a constipated population and whether such grouping might correlate with quantifiable pathophysiological measures of colonic dysfunction. METHODS: One hundred and ninety-one patients presenting to a Gastroenterology clinic with constipation and 32 constipated patients responding to a newspaper advertisement completed a 53-item, wide-ranging self-report questionnaire. One hundred of these patients had colonic transit measured scintigraphically. Factor analysis determined whether constipation-related symptoms grouped into distinct aspects of symptomatology. Cluster analysis was used to determine whether individual patients naturally group into distinct subtypes. RESULTS: Cluster analysis yielded a 4 cluster solution with the presence or absence of pain and laxative unresponsiveness providing the main descriptors. Amongst all clusters there was a considerable proportion of patients with demonstrable delayed colon transit, irritable bowel syndrome positive criteria and regular stool frequency. The majority of patients with these characteristics also reported regular laxative use. CONCLUSION: Factor analysis identified four constipation subgroups, based on severity and laxative unresponsiveness, in a constipated population. However, clear stratification into clinically identifiable groups remains imprecise.

Oropharyngeal dysphagia.

Although the aging process per se can produce measurable changes in the normal oropharyngeal swallow, these changes alone are rarely sufficient to cause clinically apparent dysphagia. The causes of oropharyngeal dysphagia in the elderly are predominantly neuromyogenic, with the most common cause being stroke. The evaluation of oropharyngeal dysphagia in the elderly involves early exclusion of structural abnormalities, detection of aspiration by videofluoroscopy which might dictate early introduction of nonoral feeding, and exclusion of underlying systemic and neuromyogenic causes that have specific therapies in their own right. Such conditions include Parkinson disease, myositis, myasthenia, and thyrotoxicosis. Management is best delivered by a multidisciplinary team involving physician, speech pathologist, nutritionist and, at times, a surgeon.

Diagnostic evaluation of dysphagia.

Taking a careful history is vital for the evaluation of dysphagia. The history will yield the likely underlying pathophysiologic process and anatomic site of the problem in most patients, and is crucial for determining whether subsequently detected radiographic or endoscopic 'anomalies' are relevant or incidental. Although the symptoms of pharyngeal dysphagia can be multiple and varied, the typical features of neurogenic pharyngeal dysphagia are highly specific, and can accurately distinguish pharyngeal from esophageal disorders. The history will also dictate whether the next diagnostic procedure should be endoscopy, a barium swallow or esophageal manometry. In some difficult cases, all three diagnostic techniques may need to be performed to establish an accurate diagnosis. Stroke is the most common cause of pharyngeal dysphagia. A videoradiographic swallow study is vital in such cases to determine the extent and timing of aspiration and the severity and mechanics of dysfunction as a prelude to therapy.

Differential relaxation and contractile responses of the human upper esophageal sphincter mediated by interplay of mucosal and deep mechanoreceptor activation.

BACKGROUND AND AIMS: the neural mechanisms of distension-induced esophagoupper esophageal sphincter (UES) reflexes have not been explored in humans. We investigated the modulation of these reflexes by mucosal anesthesia, acid exposure, and GABA(B) receptor activation. In 55 healthy human subjects, UES responses to rapid esophageal air insufflation and slow balloon distension were examined before and after pretreatment with 15 ml of topical esophageal lidocaine, esophageal HCl infusion, and baclofen 40 mg given orally. In response to rapid esophageal distension, UES can variably relax or contract. Following a mucosal blockade by topical lidocaine, the likelihood of a UES relaxation response was reduced by 11% (P < 0.01) and the likelihood of a UES contractile response was increased by 14% (P < 0.001) without alteration in the overall UES response rate. The UES contractile response to rapid esophageal air insufflation was also increased by 8% (P < 0.05) following sensitization by prior mucosal acid exposure. The UES contractile response, elicited by balloon distension, was regionally dependent (P < 0.05) (more frequent and of higher amplitude with proximal esophageal distension), and the response was attenuated by topical lidocaine (P < 0.05). Baclofen (40 mg po) had no effect on these UES reflexes. Abrupt gaseous esophageal distension activates simultaneously both excitatory and inhibitory pathways to the UES. Partial blockade of the mucosal mechanosensitive receptors permits an enhanced UES contractile response mediated by deeper esophageal mechanoreceptors. Activation of acid-sensitive esophageal mucosal chemoreceptors upregulates the UES contractile response, suggestive of a protective mechanism.

Oesophageal bolus transit and clearance by secondary peristalsis in normal individuals.

BACKGROUND: Secondary peristalsis is important for the clearance of retained refluxate or material from the oesophagus. Combined impedance and manometry can directly detect both oesophageal contraction and bolus transit. AIM: To apply combined impedance and manometry to characterize oesophageal bolus transit and clearance by secondary peristalsis in healthy individuals. METHODS: Eleven healthy volunteers underwent combined impedance and manometry with a catheter containing seven impedance-measuring segments and eight water-perfusion pressure transducers. Saline and solid agar boluses of 5 ml were applied for primary peristalsis and secondary peristalsis was stimulated by rapid mid-oesophageal injections of saline. RESULTS: The rate for complete bolus clearance of secondary peristalsis with saline injections was less than that of primary peristalsis with saline swallows (69 vs. 95%, P=0.02). No statistical difference in bolus propagation time between primary and secondary peristalsis was observed (P=0.45). Bolus presence time of secondary peristalsis was significantly longer than that of primary peristalsis for all impedance-measuring segments (all P<0.05). Solid swallows differed from saline swallows with lower rate of complete bolus transit and longer bolus transit time. CONCLUSION: Our data show that the impedance technique can successfully characterize oesophageal bolus transit and clearance by secondary peristalsis. These findings suggest that secondary peristalsis may be less effective than primary peristalsis regarding oesophageal transit and clearance of a liquid bolus.

Assessment of intraluminal impedance for the detection of pharyngeal bolus flow during swallowing in healthy adults.

Intraluminal impedance, a nonradiological method for assessing bolus flow within the gut, may be suitable for investigating pharyngeal disorders. This study evaluated an impedance technique for the detection of pharyngeal bolus flow during swallowing. Patterns of pharyngoesophageal pressure and impedance were simultaneously recorded with videofluoroscopy in 10 healthy volunteers during swallowing of liquid, semisolid, and solid boluses. The timing of bolus head and tail passage recorded by fluoroscopy was correlated with the timing of impedance drop and recovery at each recording site. Bolus swallowing produced a drop in impedance from baseline followed by a recovery to at least 50% of baseline. The timing of the pharyngeal and esophageal impedance drop correlated with the timing of the arrival of the bolus head. In the pharynx, the timing of impedance recovery was delayed relative to the timing of clearance of the bolus tail. In contrast, in the upper esophageal sphincter (UES) and proximal esophagus, the timing of impedance recovery correlated well with the timing of clearance of the bolus tail. Impedance-based estimates of pharyngoesophageal bolus clearance time correlated with true pharyngoesophageal bolus clearance time. Patterns of intraluminal impedance recorded in the pharynx during bolus swallowing are therefore more complex than those in the esophagus. During swallowing, mucosal contact between the tongue base and posterior pharyngeal wall prolongs the duration of pharyngeal impedance drop, leading to overestimation of bolus tail timing. Therefore, we conclude that intraluminal impedance measurement does not accurately reflect the bolus transit in the pharynx but does accurately reflect bolus transit across the UES and below.