High‐resolution manometry changes our views of gastrointestinal motility

High‐resolution manometry using catheters with 36 solid‐state sensors spaced 1 cm apart has already become an established technique for esophageal manometry where it has replaced water‐perfused and station pull‐through manometry. Spatiotemporal plots with color coding of pressure have greatly facilitated the analysis of esophageal peristalsis. Although suitable for the length of the esophagus, the solid‐state catheter is insufficient for the study of longer segments of the gastrointestinal tract. A new technique with fiber‐optic sensors has made it possible to construct catheters with 72–144 sensors. Studies of colonic motility have revealed that the most common motor pattern of the colon is a peristaltic contraction that travels 7–10 cm in the retrograde direction. Earlier studies using low‐resolution manometry with 7–45 cm between sensors led us to erroneous conclusions regarding direction and frequency of contractions and they largely missed both antegrade and retrograde contractions traveling short distances. Fiber‐optic high‐resolution manometry holds promise for greatly improving our understanding of gut motor physiology and hopefully also our understanding of patients with symptoms of disordered gut motility.     

Motility of the oesophagus and small bowel in adults treated for Hirschsprung’s disease during early childhood

Background Dysmotility of the upper gastrointestinal (GI) tract has been reported in children with Hirschsprung’s disease (HD). In the present study, motility of the oesophagus and the small bowel was studied in adults treated for HD during early childhood to elucidate whether there are alterations in motility of the upper GI tract in this patient group. [Correction added after online publication 15 Sep: The preceding sentence has been rephrased for better clarity.] Methods Ambulatory small bowel manometry with recording sites in duodenum/jejunum was performed in 16 adult patients with surgically treated HD and 17 healthy controls. In addition, oesophageal manometry was performed with station pull‐through technique. Key Results The essential patterns of small bowel motility were recognized in all patients and controls. During fasting, phase III of the migrating motor complex (MMC) was more prominent in patients with HD than in controls when accounting for duration and propagation velocity (P = 0.006). Phase I of the MMC was of shorter duration (P = 0.008), and phase II tended to be of longer duration (P = 0.05) in the patients. During daytime fasting, propagated clustered contractions (PCCs) were more frequent in the patients (P = 0.01). Postprandially, the patients demonstrated a higher contractile frequency (P = 0.02), a shorter duration of contractions (P = 0.008) and more frequent PCCs (P < 0.001). The patients had normal oesophageal motility. Conclusions & Inferences This study demonstrates that adult patients with HD have preserved essential patterns of oesophageal and small bowel motility. However, abnormalities mainly characterized by increased contractile activity of the small bowel during fasting and postprandially are evident. These findings indicate alterations in neuronal control of motility and persistent involvement of the upper GI tract in this disease.     

Solid-state vs water-perfused catheters to measure colonic high-amplitude propagating contractions

Background Solid‐state (SS) manometry catheters with portable data loggers offer many potential advantages over traditional water‐perfused (WP) systems, such as prolonged recordings in a more physiologic ambulatory setting and the lack of risk for water overload. The use of SS catheters has not been evaluated in comparison with perfused catheters in children. This study aims to compare data provided by SS and WP catheters in children undergoing colonic manometry studies. Methods A SS catheter and a WP catheter were taped together such that their corresponding sensors were at the same location. Simultaneous recordings were obtained using the SS and WP catheters (both 8 channels, 10 cm apart) in 15 children with severe defecation disorders referred for colonic manometry. Signals were recorded for a minimum of 1 h during fasting, 1 h after ingestion of a meal, and 1 h after the administration of bisacodyl. Solid‐state signals from the data logger were analyzed against the perfused signals. All high‐amplitude propagated contractions (HAPCs), the most recognizable and interpreted colonic motor event, were evaluated for spatial and temporal features including their durations, amplitudes, and propagation velocities. Key Results A total of 107 HAPCs were detected with SS and 91 with WP catheters. All WP‐HAPC were also observed with SS. Linear regression analysis showed that SS catheters tended to give higher readings in the presence of amplitudes <102 mmHg and lower reading with amplitudes >102 mmHg. An opposite trend was found for the duration of contractions. No significant difference was found for HAPC velocity. Conclusions & Inferences SS catheters are more sensitive in recording HAPCs in children with defecation disorders compared with the more traditional WP assembly. There is a difference in measurements of amplitude between the two systems. Solid‐state catheters offer potential advantages over WP catheters in children, being portable, safer to use, and may provide data over a more prolonged period.     

Comparison of small‐bowel motility of the human jejunum and ileum

Background Knowledge about human cyclic fasting motility (MMC) and the postprandial response is mostly based on manometric findings in the upper small intestine. Hardly any data exist on human ileal motility, as the acquisition of data has been limited by methodological concerns. The aim was to study human jejunal and ileal motility in an optimized manometric setting. Methods Solid‐state 24‐h‐manometry was performed in the jejunum and ileum of healthy individuals, applying a strict protocol for fasting, resting, and the consumption of a standardized meal. Both visual qualitative and validated computerized quantitative contraction and propagation analysis were performed. Key Results MMC occurs in similar frequency in the jejunum and ileum, but it was significantly shorter in the jejunum at night. By many characteristics, ileal motility was less intense and propagative than jejunal: less migrating clustered contractions, and slower propagation velocity and shorter distance in phases II and III, and postprandially – possibly slowing and enhancing nutrient absorption. Prolonged propagated contractions in some individuals were identified as a unique ileal propulsive pattern. Postprandially, an abrupt conversion to a digestive motility pattern occurs simultaneously independent of the region. Conclusions & Inferences We found similar basic phenomena of fasting and postprandial motility in the jejunum and ileum of healthy humans. However, different calibration of propagative and contractile activity and special motor events in the ileum may account for a different physiological role in digestion. Future studies of small‐bowel motility in healthy and diseased subjects focusing on segmental differences of proximal and distal intestine may be rewarded.     

Distention of the colon is associated with initiation of propagated contractions in children

Abstract  The presence of high-amplitude propagating contractions (HAPCs) has been identified as a marker of colonic neuromuscular integrity. The physiologic mechanisms of HAPCs initiation have yet to be determined. Distention secondary to colonic filling has been hypothesized as physiologic initiator. The aim of this study was to study the effect of intraluminal balloon distention in the colon of children with defecatory disorders. Colonic manometry was performed with a polyethylene balloon situated at the proximal end of the catheter, which was placed in the most proximal colonic segment reached during colonoscopy. A stepwise pressure controlled distention of the balloon was performed using barostat computer (10–50 mmHg). Propagated contractions were defined as those that migrated over at least three recording sites. They were divided into HAPCs, amplitude >60 mmHg and low-amplitude propagating contractions (LAPCs), amplitude <60 mmHg. Children with spontaneous HAPCs or HAPCs after bisacodyl provocation were considered to have normal motility. Twenty children completed the study. Among the 14 children with normal colonic motility, balloon distention elicited HAPCs in four and LAPCs in 10 children. No HAPC were elicited in six children with abnormal motility and LAPCs were seen in four of them. The balloon-induced propagated contractions had similar characteristics as those occurring spontaneously and after bisacodyl provocation but the pressure needed to elicit them and their amplitude was inconsistent. These findings suggest that intraluminal distention can trigger propagated contractions in children. This mechanism of action for induction of propagated contractions is not as consistent as the motor response found in response to bisacodyl administration.     

Reproducibility of antroduodenal motility during prolonged ambulatory recording

Ambulatory recording of antroduodenal manometry is a novel technique with several advantages over standard stationary manometry recording. Although the feasibility of this technique in clinical practice has been demonstrated, reproducibility of antroduodenal motility recorded by means of ambulatory manometry has not been investigated. To test whether antroduodenal motility recorded by ambulatory manometry is reproducible, we performed two 24-h ambulatory antroduodenal manometry recordings in 18 healthy subjects according to an identical protocol with a 1-week interval. Motility was recorded with a five-channel solid-state catheter. Postprandial motility was recorded after consumption of two test meals and interdigestive motility was recorded nocturnally. Postprandial antroduodenal motor characteristics were identical between the separate recordings. The number and duration of nocturnal cycles of the interdigestive migrating motor complex were also in the same range. Phase III characteristics in general were not different between the two recordings. Only minor alterations were observed in the duration of phase III motor fronts with duodenal onset and in the number of interdigestive cycles concluded by duodenal onset phase III. Parameters obtained by qualitative analysis were comparable between the two recordings. The antroduodenal motility pattern, when measured by ambulatory recording with solid state catheters under standardized conditions, is very reproducible.     

Determinants of postprandial flow across the human ileocaecal junction: a combined manometric and scintigraphic study

Abstract The relationships between ileocolonic motor patterns and flow have not been defined in humans. Utilizing simultaneous ileocolonic manometry and scintiscanning, we aimed to examine this relationship and test the hypotheses that ileal propagating sequences (PSs) underlie caecal filling, that caecal filling is a stimulus for proximal colonic PSs and that the ileocolonic junction (ICJ) regulates flow between the small and large bowel. In six healthy volunteers, a 5‐m‐long nasocolonic manometry catheter was positioned such that 16 recording sites, spaced at 7.5‐cm intervals, spanned the ileum and proximal colon. Subjects were positioned under a gamma camera 30 MBq of ^99mTc sulphur colloid was instilled, 22.5 cm proximal to the ICJ. Isotopic images were recorded (10 s per frame) and synchronized with the manometric trace. We identified 171 ileal PSs, 47 caecal PSs and 117 discrete episodes of caecal filling. Of the 117 episodes of caecal filling, 72% were associated temporally with ileal PSs. Conversely, 87% of ileal PSs were associated with caecal filling. Of the PSs originating in the caecum, 90% were temporally associated with caecal filling. We conclude that ileal PSs are highly propulsive and are the major determinant of episodic caecal filling and that caecal filling may be a major stimulus for caecal propagating sequences.     

Distinctive motor responses to human acute salmonellosis in the jejunum and ileum

Given the differences that normally exist in jejunal and Heal motility patterns, we wished to determine whether these regions respond differently to acute enteric infections. In 10 patients with acute gastroenteritis induced by Salmonella infection and 12 healthy individuals jejunal and Heal motility was recorded at eight equidistant sites by a manometric system for 6 h during fasting. All were healthy individuals, but only three of 10 patients exhibited the cyclic inter digestive motor complex; 82 ± 9 min duration in healthy individuals (mean ± SE). In the jejenum, patients exhibited short bursts of intense activity (6.3 ± 1.6 bursts/subject in patients vs. 1.8 ± 0.5 in controls; P < 0.05); burst activity was scarce in the ileum. In contrast to healthy subjects, patients exhibited prolonged periods (64 ± 3 min duration) of Heal motor quiescence, that accounted for 32 ± 11% of recording time; such silent periods were not observed in the jejunum. Prolonged propagated ileal contractions were observed only in two healthy subjects, but in seven out of 10 patients. These data indicate that acute Salmonella infection magnifies the motor differences between the jejunum and the ileum; both regions generate aberrant and markedly different dysmotility patterns.     

Pseudo-obstruction Syndrome in Multiple Sclerosis

Three patients with long-standing multiple sclerosis were found to have clinical features of chronic intestinal pseudo-obstruction consisting of nausea, vomiting, abdominal pain, and distention after meals. Radiographic studies demonstrated dilated loops of bowel without evidence of mechanical obstruction. In addition to standard clinical data, results of jejunal manometry in the patients were compared with those of 10 normal volunteers. Phase III of the migrating motor complex activity fronts occurred in two of the three patients during at least 3 hours of recording. Some contractions exhibited higher than normal amplitudes (>90 mm Hg), but the frequency, mean amplitudes, and motility indices were similar to those recorded in the normal volunteers. After a meal the frequency of contractions was reduced, although the amplitudes were normal to high (>90 mm Hg), and some contractions exhibited a tonic or prolonged component. Postprandial contractions were erratic with periods of intense activity alternating with quiescence. These manometric findings are most compatible with a neuropathic process. When pseudo-obstruction compromised assimilation of orally administered nutrients in these patients, central venous nutrition was required.     

Ambulatory Esophageal Manometry: Comparison of Expert and Computer-Aided Analyses

This study describes the validation of a computer program for automated analysis of ambulatory 24-hour two-channel esophageal manometry. The program's ability to characterize contractions and to calculate their duration and amplitude was validated against manual evaluation. An independent reference standard for the identification and classification of contractions was established by submitting representative recordings to a group of 14 experts in upper gastrointestinal motility; the program's ability to identify and classify contractions was then validated against the majority verdict of the experts. The results show an excellent correlation between the manual and computer evaluations of both contraction amplitude (p = 0.9957) and duration (p = 0.8241). The concordance between the experts was also excellent: 97 (72%) of 135 pressure events were classified identically by 12 or more experts. Computer-aided manometry analysis (CAMA) had a sensitivity of 98.9% and a specificity of 93.5% for the detection of contractions, with sensitivities of 94.7% and 84.4% and specificities of 94.9% and 94.2% for the classification of propagated and nonpropagated contractions, respectively.     

High amplitude propagated contractions

While most colonic motor activity is segmental and non‐propulsive, colonic high amplitude propagated contractions (HAPC) can transfer colonic contents over long distances and often precede defecation. High amplitude propagated contractions occur spontaneously, in response to pharmacological agents or colonic distention. A subset of patients with slow transit constipation have fewer HAPC. In this issue of Neurogastroenterology and Motility, Rodriguez et al. report that anal relaxation during spontaneous and bisacodyl‐induced HAPC exceeds anal relaxation during rectal distention in constipated children undergoing colonic manometry. Moreover, and consistent with a neural mechanism, anal relaxation often precedes arrival of HAPC in the left colon. High amplitude propagated contractions are also used to evaluate the motor response to a meal and pharmacological stimuli (e.g., bisacodyl, neostigmine) and to identify colonic inertia during colonic motility testing in chronic constipation. This editorial comprehensively reviews the characteristics, physiology and pharmacology of HAPC, their assessment by manometry, and relevance to constipation and diarrhea.     

Periodic colonic motor activity identified by 24-h pancolonic ambulatory manometry in humans

The pattern of colonic motor activity in healthy humans has not been fully elucidated to date. The aim of this study was to evaluate colorectal motor activity employing 24-h ambulant pancolonic manometry. Ten healthy volunteers (6F, 4M), aged 19-31 years were studied. Motor activity was measured using two custom-made silicone coated catheters, each with five solid-state pressure transducers. No bowel preparation or sedation was used. The study period was 24 h. A total of 232 h of recording was obtained. Sixty-three high amplitude propagated contractions were observed, median six per 24-h period. Low-amplitude colonic contractile activity showed regional and diurnal variations. Frequency of contraction was highest in the right colon [median 5.26 cpm (cycles per minute)], and transverse colon and splenic flexure (median 5.15 cpm). The interval between colonic motor complexes was shortest in the transverse colon and splenic flexure. This study introduces a new technique for the evaluation of colorectal motor activity. Subjects were studied in an ambulant setting in their own environment ensuring that this method of study is as physiological as possible. This study demonstrates that colonic motor activity has two main components: high amplitude propagated contractions and low amplitude colonic contractile activity.     

Validation of antroduodenal motility measurements made by echo-planar magnetic resonance imaging

Echo planar imaging, a development of magnetic resonance imaging, can produce snapshot images of the stomach and antroduodenal segment in as little as 64 msec and can be more useful than conventional techniques when assessing motility. The aim of this study was to compare antroduodenal motility measured by simultaneous perfused tube manometry and echo planar imaging. Ten volunteers were studied following the ingestion of 500 mL water or 500 mL porridge. Antroduodenal images, with acquisition times of 130 msec, were taken at 3-sec intervals, synchronized with motility traces and presented as a split-screen video. This allowed direct visual comparison of gastric wall movement and motility to be made. Contractions were confined to either the stomach or the duodenum or propagated across the antroduodenal segment. Over 4550 images were available for analysis. A larger number of propagated contractions were recorded with echo planar imaging in both water (P = 0.03) and food (P = 0.02) groups, whereas manometry detected a greater number of isolated duodenal pressure waves (P = 0.005). The contraction rate for water and food studies was similar, but direct visualization indicated that the manometric technique under-detected propagated events. The ability of echo planar imaging to record antroduodenal contractile activity provides a new insight into the role of occlusive and nonocclusive contractions during gastric emptying.     

Low-dose lactulose produces a tonic contraction in the human colon

Lactulose (10-20 g day(-1)) is used to treat constipation. At this therapeutic dose, its effects on colonic motility remain unknown. Twenty-two healthy subjects swallowed a probe with an infusion catheter, six perfused catheters and a balloon connected to a barostat. Colonic phasic and tonic motor activity was recorded in fasting state. In group 1, four volunteers ingested 15 g lactulose and motility was recorded for 5 h after entry of lactulose into the caecum; in group 2, motility was recorded during (3 h) and 2 h after intracolonic infusion of isoosmotic and isovolumetric solutions containing sodium chloride alone (n = 9) or with 15 g lactulose (n = 9). In a last group of volunteers, isotopic colonic transit after ingestion of lactulose (10 g,n = 9) was assessed and compared with a control group (n = 17). Ingestion or intracolonic infusion of 15 g lactulose significantly decreased barostat bag volume (maximal decrease: 45 +/- 12% and 35 +/- 9% of basal value respectively). Phasic contractions remained unchanged. Tonic and phasic motility was unchanged by the isotonic and isovolumetric infusion of saline. Ingestion of lactulose significantly accelerated isotopic colonic transit time compared with the control group. We conclude that in healthy humans, 10-15 g ingestion or intracaecal infusion of lactulose produces a prolonged tonic contraction that may be involved in the laxative effect of lactulose.     

Disposable balloon-based oesophageal motility catheters: comparison with solid-state transducers.

BACKGROUND: Current oesophageal manometry systems use either water-perfused or solid-state pressure transducers. Recently developed single-use disposable catheters use small balloons prefilled with air that transmit the pressure of oesophageal contractions to external transducers. AIM: To compare data obtained from single-use disposable balloon catheters to data from solid-state systems. METHODS: Healthy volunteers, patients with ineffective oesophageal motility and nutcracker oesophagus were studied to include a broad range of pressures. A single-use disposable Clinical Innovations (CI) catheter was placed adjacent to a solid-state Konigsberg Instruments (KI) catheter with pressure transducers at 5, 10, 15 and 20 cm above the lower oesophageal sphincter (LOS). Subjects received liquid and viscous swallows at 30-s intervals. Healthy volunteers received additional sets of swallows while having only one catheter in the oesophagus. RESULTS: When both catheters were present in the oesophagus, no differences were noted between mean pressure measurements in the distal oesophagus and there was good correlation between pressures recorded in response to individual swallows. When present alone in the oesophagus the CI catheter recorded lower mean pressures compared with the KI catheter. Overall there was good agreement in classifying swallows as normal, ineffective and simultaneous. CONCLUSION: Single-use oesophageal manometry catheters are promising alternatives to solid-state manometry systems in measuring intra-oesophageal pressures.     

Effect of sildenafil, a phosphodiesterase-5 inhibitor, on oesophageal peristalsis and lower oesophageal sphincter function in cats.

The propagation of oesophageal peristaltic contractions and lower oesophageal sphincter (LOS) relaxation depends on neural release of nitric oxide (NO) which acts to increase intracellular cGMP. Sildenafil, a phosphodiesterase-5 inhibitor that increases cGMP, reduces basal LOS pressure in patients with achalasia. We investigated the effect of sildenafil on the propagation of oesophageal contractions and LOS relaxation in the cat. Oesophageal manometry was performed in five cats under light sedation. Peristaltic contractions were monitored at 1, 2, 3, 4 and 8 cm proximal to the LOS, at the LOS using a Dent sleeve, and at 3 cm distal to the upper oesophageal sphincter. Swallow-induced oesophageal contractions and LOS relaxation were recorded during 30 min before and 30 min after intravenous administration of sildenafil. Sildenafil reduced the amplitude of oesophageal contractions only in the smooth muscle oesophagus. The latency from swallow to distal oesophageal contractions was significantly delayed. LOS pressure was significantly reduced but the relaxation nadir was not modified by sildenafil. Sildenafil has profound effects on oesophageal motility: it modifies propagation and amplitude of oesophageal contractions and reduces LOS pressure. Slowing down the propagation of contractions in the transitional zone between the striated and smooth muscle can be a useful tool in patients with segmental aperistalsis or intermittent simultaneous contractions, while the effect on the LOS can benefit patients with achalasia.     

Fermentation of starch stimulates propagated contractions in the human colon

Background In healthy humans, up to 30 g of daily ingested starch escape small intestinal digestion, and are fermented in the colon. This physiological starch malabsorption could modify colonic motility through metabolites such as short‐chain fatty acids produced by fermentation. Methods Ten healthy volunteers swallowed a probe, consisting of an infusion catheter, six perfused catheters and a balloon connected to a barostat. On two consecutive days colonic motility was recorded in fasting subjects in the basal state (1 h), and then during (3 h), and after (2 h) the intracolonic infusion of 750 mL of isoosmotic and isovolumetric solutions containing sodium chloride with or without 15 g wheat starch. We determined (i) the volume of hydrogen and methane exhaled in breath, (ii) a global motility index and the number of high amplitude propagated contractions (HAPCs), and (iii) the mean balloon volume, reflecting the tonic motor activity. Key Results [median (IQR)] Compared to the basal period, colonic infusion of starch or saline did not modify the colonic motility index and tone. However, the number of HAPCs was significantly higher during and after infusion of starch than of saline [4.5 (2.75–6.5) vs 0.96 (0–2.66)/5 h, starch vs saline respectively; P = 0.011]. Conclusions & Inferences In healthy humans, colonic fermentation of a physiological malabsorbed amount of starch has no effect on the tonic and phasic colonic motor activities, but produces a significant increase in the number of HAPCs. This may participate in the physiological propulsion of colonic contents.     

Motor patterns and propulsion in the rat intestine in vivo recorded by spatio-temporal maps

We have used spatio-temporal maps derived from video images to investigate propagated contractions of the rat small intestine in vivo. The abdomen, including an exteriorized segment of jejunum, was housed in a humid chamber with a viewing window. Video records were converted to spatio-temporal maps of jejunal diameter changes. Intraluminal pressure and fluid outflow were measured. Contractions occupied 3.8 +/- 0.2 cm of intestine and propagated anally at 3.1 +/- 0.2 mm s(-1) when baseline pressure was 4 mmHg. Contractions at any one point lasted 8.7 +/- 0.6 s. Contractions often occurred in clusters; within cluster frequencies were 2.28 +/- 0.04 min(-1). Pressure waves, with amplitudes greater than about 9 mmHg, expelled fluid when the baseline pressure was 4 mmHg. In the presence of L-NAME, circular muscle contractions occurred at a high frequency, but they were not propagated. We conclude that video recording methods give good spatio-temporal resolution of intestinal movement when applied in vivo. They reveal neurally-mediated propulsive contractions, similar to those previously recorded from intestinal segments in vitro. The propagated contractions had speeds of propagation that were slower and frequencies of occurrence that were less than speeds and frequencies of slow waves in the rat small intestine.     

Ambulatory long-term jejunal manometry in diabetic patients with cardiac autonomic neuropathy

Concerning alteration of small bowel motility in diabetic patients with autonomic neuropathy controversial data were obtained with stationary manometry and over a limited period of time. The aim of our study was to examine ambulatory 24 h jejunal motility in 15 diabetic patients with cardiac autonomic neuropathy compared with data obtained in 50 healthy controls. Twenty-four hour motility was recorded in the proximal jejunum with a portable datalogger and tube-mounted miniature pressure sensors. Diurnal and nocturnal fasting motility and the motor response to a standardized evening meal of 600 kcal were evaluated by visual and computer-aided analysis. The following abnormalities were found during fasting motility (n = number of patients): absence of phase III over 24 h (n = 2), retrograde migration or simultaneous occurrence of phase III (n = 5). During postprandial motility irregular bursts with tonic baseline elevation (n = 3) and contraction frequencies below the range of controls (n = 8) occurred. Furthermore patients exhibited an inversion of the normal relationship between phase I and phase II during nocturnal MMC – cycles, and discrete clustered contractions were diminished (P < 0.01) in the fasting and digestive state. All patients showed at least one abnormal manometric finding. We conclude that small bowel motility in diabetic autonomic neuropathy is characterized by disturbances in the generation and aboral migration of phase III, an altered circadian variability of the MMC cycle and by postprandial hypomotility.