Multichannel intraluminal impedance: general principles and technical issues

Multichannel intraluminal impedance (MII) is a new technology that allows detection of bolus movement without the use of external radiation or radiolabeled substances. The principles of MII are based on changes in resistance to alternating electrical current (impedance) induced by the presence of various boluses within the esophagus. The timing of changes in multiple impedance-measuring segments in the esophagus allows determination of the direction of bolus movement. Combined MII and manometry (MII-EM) provides simultaneous information on intraesophageal pressures and bolus transit, offers the ability to monitor all types of reflux, and allows the detection of the physical (liquid, gas, or mixed) and chemical (acid, nonacid) characteristics of the gastroesophageal refluxate.     

Solid-state computerized manometry improves diagnostic yield in pharyngeal dysphagia: simultaneous videoradiography and manometry in dysphagia patients with normal barium swallows

Objective:

Dynamic barium radiology with cine- or video recording has been the most frequently used technique for assessing patients with pharyngeal dysphagia. Although the diagnostic yield of the barium swallow has been high, many patients with pharyngeal dysphagia have normal dynamic barium radiology and remain a diagnostic dilemma. Could manometry add important diagnostic information in these patients?

Material and methods:

We examined 19 patients (12 men and 7 women, mean age 47 years, range 19–69 years) with pharyngeal dysphagia but a normal barium swallow with simultaneous videoradiography and pharyngeal manometry and compared their manometry to that found in 24 normal volunteers (11 men and 13 women, mean age 37 years, range 23–59 years).

Results:

Comparing mean values, the patient group showed statistically significant differences from the control group for eight of 10 manometric parameters. Fourteen of 19 patients showed at least one (five patients) and in most cases multiple (nine patients) manometric abnormalities (values exceeding normal mean by ±2SD) which might have contributed to their dysphagia: five patients with high upper esophageal sphincter (UES) resting pressures, five with high LIES residual pressures, three with weak pharyngeal contractions, three with pharyngeal “spasms,” seven with prolonged contraction/relaxation times, five with reduced compliance, and seven with UES/P incoordination.

Conclusions:

Solid-state computerized manometry is a useful adjunct to videoradiography and can provide potentially important additional information in the diagnosis of dysphagia patients.     

Relationship of radionuclide liquid bolus transport and esophageal manometry

Using simultaneous esophageal manometry and radionuclide transit studies, we compared liquid bolus transport with the various parameters of esophageal contractions. Study subjects included seven normal individuals, six patients with the "nutcracker esophagus" (mean distal peristaltic amplitude greater than 180 mm Hg), and three patients with spastic motility disorders. Manometric studies were performed when the subjects were in the basal state and after intravenous administration of edrophonium and atropine. Simultaneous radionuclide studies were done with subjects in the supine position by swallows of 250 mu Ci technetium Tc 99m sulfur colloid in 10 ml water. We found that normal liquid bolus transport (less than 15 seconds) is primarily dependent on the presence of a peristaltic wave front throughout the esophagus. Above a threshold pressure of 30 mm Hg, liquid transport was not affected by amplitude (33 to 500 mm Hg) or duration (3 to 15 seconds) of esophageal contractions. Repetitive wave forms also gave normal transit times as long as the wave front was peristaltic in onset. There was a significant inverse correlation (-0.65; P less than 0.001) between liquid transit time and peristaltic velocity. Prolonged radionuclide transport (30 to less than 50 seconds) was observed only with nonperistaltic contractions and very low amplitude (15 to 30 mm Hg) peristaltic waves.     

Esophageal motility disorders with thoracic pain of unknown origin

35 patients with angina-like chest pain underwent esophageal manometry after a coronary artery disease had been ruled out by angiography. Furthermore, patients after gastric or esophageal surgery, with pathologic upper gastrointestinal endoscopy or with pathologic gastroesophageal reflux as seen on 24-hour-pH-metry were excluded from this study. 29 out of 35 patients (83%) had a normal manometric study, six patients (17%) had a motility disorder; five of these showed an unspecific dismotility pattern and were asymptomatic while the study was done; only one patient presented with esophageal spasm. Since only this latter patient was symptomatic while the study was done, a correlation between symptoms and this motility disorder seems likely. --If pathologic gastroesophageal reflux has been ruled out, esophageal manometry can establish a diagnosis in only 3% of patients with angina-like chest pain without esophageal symptoms (dysphagia, odynophagia, heartburn or regurgitation). We conclude that this complicated examination should not be done in these patients.     

évaluation des anomalies motrices oesophagiennes au cours de la dysphagie avec endoscopie digestive haute normale

Aims

Dysphagia is considered, rightly, as an alarm symptom requiring upper endoscopy which is sometimes normal. Esophageal manometry is the second examination performed to explore this symptom. The aims of this study are to evaluate the frequency and to identify the type of oesophageal motility disorders in patients with dysphagia with a normal endoscopy.

Patients and methods

It was a retrospective study including patients with dysphagia with normal upper endoscopy and referred to our department for esophageal manometry. The variables assessed were: age; gender; dysphagia duration; LES pressure and relaxation on swallowing; amplitude, duration and propagation of peristaltic contractions.

Results

226 patients were included: 114 women (50.4 %) and 112 men (49.6 %) whose mean age was 44.23 ± 16.50 years. The median duration of dysphagia was 12 months [6.25–48]. Dysphagia was isolated in 38 cases (16.8 %). Esophageal manometry was abnormal in 144 patients (63.7 %). The inadequate relaxation (achalasia) was the most frequent primary motor disorder in these patients (36.3 %).

Conclusion

In patients with dysphagia with normal upper endoscopy, esophageal manometry should be routinely performed to diagnose esophageal motility disorders. These are noted in 2 of 3 patients. Achalasia is a primary motor disorder most often frequent.     

脑卒中合并吞咽困难患者上食管括约肌动力特征

【目的】探讨脑卒中吞咽困难患者上食管括约肌（UEs）动力特征。【方法】急性脑卒中伴吞咽困难的患者20例（卒中组）,健康志愿者19名（对照组）,行高分辨率食管测压检查,测量两组对象的UES的静息压、残余压、松弛持续时间、恢复时间、松弛前峰压及松弛后峰压。【结果】卒中组患者UES静息压力、UES松弛持续时间、UES松弛后峰压、UES松弛恢复时间均明显低于对照组（P〈0．05）,UES松弛时残余压明显高于对照组（P〈0．05）,两组患者UES松弛前峰压比较无明显差别（P〉0．05）。【结论】脑卒中合并吞咽困难患者存在UES异常动力功能,异常的UES动力功能对吞咽困难患者气道保护不利,可能增加并发症的风险。     

Diagnosis and treatment of esophageal motility disorders

Apart from gastroesophageal reflux disease, achalasia, non-cardiac chest pain and functional dysphagia are the most important manifestations of disturbed esophageal motility. Achalasia is characterized by esophageal aperistalsis and impaired deglutitive relaxation of the lower esophageal sphincter. The morphological correlate is a degeneration of nitrergic neurons in the myenteric plexus. Diagnosis is based on barium esophagram or esophageal manometry with the latter setting the gold standard. Endoscopic exclusion of a tumor at the gastroesophageal junction is mandatory. Appropriate therapeutic interventions are pneumatic dilatation or (laparoscopic myotomy) of lower esophageal sphincter. In patients unfit for these procedures endoscopic injection of botulinum toxin into the lower esophageal sphincter is appropriate. Non-cardiac chest pain may be of esophageal origin. Gastroesophageal reflux, spastic motility disorders and visceral hypersensitivity are arguable underlying mechanisms. The most important diagnostic procedure is 24 h esophageal pH metry correlating symptoms and reflux episodes. Proton pump inhibitors and tricyclic antidepressants serving as visceral analgesics are appropriate therapeutic approaches. Functional dysphagia defines the sensation of impaired passage without mechanical obstruction or a neuromuscular disease with known pathology, e.g. scleroderma. Impaired transit is proven by esophageal scintigraphy or radiogram both using solid boluses. Manometry assesses the underlying mechanisms.     

Long-term results of laparoscopic partial posterior fundoplication in patients with esophageal reflux and disorders of esophageal peristalsis

BACKGROUND: Gastrosophageal reflux disease (GERD) of long duration is frequently associated with impaired esophageal body motility. This condition has been considered unsuitable for antireflux surgery. METHODS: In order to investigate the outcome of antireflux surgery in the presence of impaired esophageal peristalsis, we studied 67 consecutive GERD patients with poor esophageal body function who underwent laparoscopic partial posterior fundoplication. A standardized questionnaire, upper GI endoscopy, esophageal manometry and 24-hour pH monitoring were performed preoperatively and at a median of 28 months (range, 6-54 months) postoperatively. Esophageal motility was analyzed for contraction amplitudes in the distal two thirds of the esophagus (level 3, 4, and 5), frequency of peristaltic, simultaneous and interrupted waves and total number of defective propagations. In addition, parameters defining the function of the lower esophageal sphincter (LES) were-evaluated. RESULTS: Following antireflux surgery 65 patients (97%) were free of heartburn and regurgitation and had no esophagitis on endoscopy, confirmed by histology. The rate of dysphagia was reduced from 49% preoperatively to 9% postoperatively (p < 0.001). There was significant improvement in esophageal peristalsis after the antireflux procedure. The median DeMeester reflux score was reduced from 33.3 to 1.1 (p < 0.001). Lower esophageal sphincter pressure and intra-abdominal length were normal after surgery. CONCLUSIONS: Partial posterior fundoplication provides an effective antireflux barrier in patients with impaired esophageal body motility in the long term. Postoperative dysphagia is avoided by improving esophageal body function.     

Diagnosis of esophageal motor disorders: A prospective study comparing barium swallow,food barium mixture,and continuous swallows with manometry

Radiography and manometry of the esophagus were compared in 77 patients consecutively referred for manometric investigation on suspicion of esophageal motility disorder. Radiography and manometry were carried out simultaneously, and the results were assessed blindly. The examination comprised barium swallow, bread barium swallow, and barium swilling. Considering manometry as the standard, the overall sensitivity and specificity of the radiologic examinations were 90.4% and 92.0%, respectively. We conclude that radiology is an excellent investigation for the separation of patients with and without esophageal motility disorders, but correct subclassification often required manometry.     

Diagnosis of esophageal motility disorders

Esophageal motility disorders are now known to be a heterogeneous group of conditions that commonly cause dysphagia and chest pain. Motor dysphagia is usually provoked by solids and liquids (in contrast to mechanical dysphagia, which is usually provoked by solids only). Chest pain with these disorders is nonspecific and can mimic angina pectoris. In many patients with diffuse esophageal spasm or nutcracker esophagus, pain appears to be caused by abnormal sensory function rather than contraction abnormalities. Barium esophagography and esophageal manometry are complementary studies in the evaluation of motility disorders.     

The effect of glucagon on esophageal peristalsis and clearance

The effect of 0.5 mg intravenous glucagon on esophageal peristalsis and transit of water and barium was studied in nine healthy subjects by concurrent videofluoroscopy and manometry.Glucagon lowered manometric peristaltic amplitude in both mid- and distal esophagus. This reached significance (p=0.0075) in the distal 3 cm of the esophagus 2 min after the injection. The efficiency of esophageal stripping was also reduced (increased proximal escape on fluoroscopy), and became significant (p=0.05) at 2 min after the injection of glucagon.     

Movement of the Feline Esophagus Associated with Respiration and Peristalsis. AN EVALUATION USING TANTALUM MARKERS

The outer, lateral esophageal walls in the distal half of the esophagus in each of five cats were labeled with small tantalum wires. About 8 wk later, esophageal motion associated with respiration and peristalsis, induced by injecting barium boli (5 ml each) into the proximal esophagus, was recorded on cine and serial biplane roentgenograms while recording intraluminal esophageal pressures simultaneously by manometry. Esophageal motion was also evaluated without a manometric tube in place. The coordinates for each marker were digitized and a computer was used to plot marker position against time. During respiration, the markers passively made a shallow, 2-10 mm excursion on the longitudinal esophageal axis. This movement was synchronous with thoracic and diaphragmatic movement and changes in intraluminal esophageal pressure. Immediately after the onset of peristalsis, the markers made a pronounced oral movement of 10 mm or more above their mean respiratory position, as if to engulf the bolus. Markers in opposing esophageal walls approximated one another and commenced an aboral movement as the bolus tail, which was essentially co-incident with onset of the manometric pressure complex, passed the marker sites. The markers returned to their respective rest positions essentially coincident with passage of the pressure complex peak and then moved below their respective rest positions. The aboral excursion occurred predominantly after the bolus had emptied into the stomach. The magnitude and duration of oral excursion was significantly greater for the distal than for the more proximal markers; conversely, the magnitude and duration of aboral excursion was greater for the proximal than for the more distal markers. During the peristaltic sequence, the labeled portion of the esophagus shortened from 26 to 46% of its resting length. No evidence of esophageal torque was shown. These findings suggest that both the longitudinal and circular esophageal musculature play an active and important role during peristaltic transport of a bolus through the esophagus.     

Intraesophageal balloon distention in the manometric evaluation of chest pain

Drug provocation is routinely used during esophageal manometry in the evaluation of chest pain of presumed esophageal origin. As significant side effects have been associated with the use of drugs in provocation, and these provocative tests are inadequately sensitive to exclude esophageal etiology as the cause of chest pain, alternative provocative tests have been sought. Intraesophageal balloon distention (IEBD) has recently been reintroduced as a method of pain provocation in the manometric evaluation of chest pain. IEBD produces pain on distention which resolves immediately on deflation. To evaluate graded IEBD as an effective and safe method of pain provocation, 66 consecutive patients presenting with chest pain and 10 asymptomatic volunteers were studied. We conclude that balloon distention is an effective and safe method of pain provocation and can easily be performed in conjunction with standard esophageal manometry.     

Does Dysphagia Indicate Recurrence of Benign Esophageal Strictures?

Esophageal dilatation in dysphagic patients with benign strictures is usually considered successful if the patients' dysphagia is alleviated. However, the relation between dysphagia and the diameter of a stricture is not well understood. Moreover, the dysphagia may also be caused by an underlying esophageal motor disorder. In order to compare symptoms and objective measurements of esophageal stricture, 28 patients were studied with interview and a radiologic esophagram. The latter included swallowing of a solid bolus. All patients underwent successful balloon dilatation at least one month prior to this study. Recurrence of a stricture with a diameter of less than 13 mm was diagnosed by the barium swallow in 21 patients. Recurrence of dysphagia was seen in 15 patients. Thirteen patients denied any swallowing symptoms. Chest pain was present in 9 patients. Of 15 patients with dysphagia 2 (13%) had no narrowing but severe esophageal dysmotility. Of 13 patients without dysphagia 9 (69%) had a stricture with a diameter of 13 mm or less. Of 21 patients with a stricture of 13 mm or less 14 (67%) were symptomatic while 7 (33%) were asymptomatic. Four of 11 patients with retrosternal pain had a stricture of less than 10 mm. Three patients with retrosternal pain and obstruction had severe esophageal dysmotility. Whether or not the patients have dysphagia may be more related to diet and eating habits than to the true diameter of their esophageal narrowing. We conclude that the clinical history is non-reliable for evaluating the results of esophageal stricture dilatation. In order to get an objective measurement of therapeutic outcome, barium swallow including a solid bolus is recommended.     

Esophageal dysmotility in patients who have eosinophilic esophagitis

The understanding of esophageal motility alterations in patients who have eosinophilic esophagitis (EE) is in its infancy despite the common presenting complaint of dysphagia. A diversity of motility disorders has been reported in patients who have EE including achalasia, diffuse esophageal spasm, nutcracker esophagus, and nonspecific motility alterations including high-amplitude esophageal body contractions, tertiary contractions, abnormalities in lower esophageal sphincter pressure, and other peristaltic problems. Some evidence suggests that treatment of EE will improve motility. Technological advances such as high-resolution manometry and combined manometry with impedance may provide new insight into more subtle motility abnormalities.     

Apport des nouvelles méthodes d’exploration pour la classification des troubles moteurs œsophagiens

The development of high resolution manometry has modified the diagnostic approach of esophageal motility disorders. The use of a high number of electronic sensors together with the pressure variations displayed as esophageal pressure topography have greatly facilitated data interpretation. The diagnostic yield for dysphagia has increased by 10-20% thanks to these improvements. The Chicago classification is based on both relaxation of the esophago-gastric junction and the pattern of esophageal contractility. This diagnostic algorithm allows classifying esophageal motor disorders as achalasia, hypercontractile, or hypocontractile disorders. Whether this classification will positively impact the outcome of patients with esophageal motor disorders remains to be determined.     

Esophageal manometrics in patients with angina-like chest pain.

Fifty-eight patients with angina-like chest pain had esophageal manometric testing. Forty-three had no evidence of coronary artery disease at the time of referral or at subsequent contact; 15 patients were proven to have coronary artery disease. High-amplitude contraction waves were the most frequently found manometric abnormality (15 patients). Less frequent were increased duration of contractions, achalasia, and diffuse esophageal spasm; the latter was present in only 3 patients. An approach to the interpretation of information obtained during manometry is presented. Using this approach, the esophagus was strongly implicated as the cause of the pain in 20 patients and was suspect in 18 others. Seven patients had results that exonerated the esophagus, and in the 13 remaining individuals, the esophagus was probably not the offending organ.     

高频腔内超声对胃食管反流患者食管运动功能的评价

目的 应用高频腔内超声与食管测压同步检测胃食管反流病(GERD)患者的食管运动功能异常情况,并尝试论证腔内超声评估食管运动功能异常的有效性和可行性,以及食管压力与食管壁肌层厚度之间的关系.方法 10例经内镜及24 h食管pH检测确诊为GERD的患者,5例正常志愿者作为对照.经鼻腔导入高频超声探头(频率20 MHz,直径1.9 mm)及四通道水灌注式测压导管,在观察静息及吞咽时食管压力变化的同时,同步记录食管的运动影像,并计算出下食管括约肌上端5 cm、10 cm、1 5 cm及20 cm处食管环形肌和纵形肌的收缩指数、收缩周期及食管截面积.同时,通过测压导管同步监测湿咽时食管的最大压力值,计算其与同一位置的食管最大肌层厚度之间的相关性.结果 10例GERD患者与正常对照组相比,食管各段环形肌、纵形肌收缩指数均明显缩小(P＜0.05);收缩周期有延长的趋势;而最大截面积与正常对照组差异无统计学意义(P＞0.05).食管各段的最大压力值与同一部位的最大肌层厚度之间存在正相关(r=0.552～0.736).结论 食管各部位的最大压力值与最大肌层厚度之间存在正相关;GERD患者存在食管运动功能的异常,食管壁的舒缩能力下降以及收缩周期延长可能影响食管的廓清力,从而与GERD的发病有直接关系;同时,高频腔内超声为功能性胃肠病的诊断及其临床研究提供了一种新的方法.     

Dysphagia following stroke: quantitative evaluation of pharyngeal transit times.

Forty stroke subjects referred for dysphagia and studied by videofluoroscopy were compared with 16 individuals with no known pharyngeal swallowing difficulty. Kinematic pharyngeal transit time was defined as the time from the first movement of the bolus posteriorly resulting in a complete swallow to the return of the epiglottis to its original position. The mean transit time was 1.00 second for the comparative group and 6.15 seconds for the stroke group (p less than 0.001). Other component transit times are described and were all significantly prolonged for the stroke group. There was no significant difference in transit times between right-sided and left-sided lesions except for the segmental interval from onset of bolus movement to arrival at the valleculae, which was significant at p = 0.05. Measurement of transit times using the method described in this study requires equipment available in most hospitals. These measurements may be used in the evaluation of dysphagia in various pathologic disorders, in following the progress of patients with dysphagia, and in evaluating the effects of remedial therapies.     

Comparison of investigation modalities for evaluation of esophageal peristaltic function

We reviewed the recent literature concerning investigations of esophageal peristaltic function. The gold standard for the assessment of esophageal peristaltic function is manometry with pH monitoring. Even with this investigation modality, however, we are in fact doing no more than estimating esophageal peristaltic function from the manometry and pH results. With esophageal fluoroscopy and scintigraphy, where we observe esophageal motility, there are problems with radiation exposure and handling of radioactive agents that make widespread use difficult. In recent years, the development of multichannel intraluminal impedance (MII) manometry has allowed simultaneous measurement of intraesophageal pressure and assessment of esophageal peristalsis. Using MII it is also possible to distinguish whether gas or liquid is passing down the esophagus. When manometry is performed in conjunction with transnasal esophagogastroduodenoscopy, with this unique combination it is possible to measure the intraesophageal pressure while actually observing the swallowing motion at the same time. Assessment of esophageal peristaltic function is now moving from simple measurement of intraesophageal pressure to simultaneous impedance manometry and endoscopic observation of esophageal peristalsis itself.