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Do gastric myoelectrical abnormalities predict delayed gastric emptying?
April 1995
Motility and Nerve-Gut Interactions
• HYPOPHARYNGEAL COMPLIANCE AMONG BOLUS VOLUMES REGULATES OUTFLOW DURING SWALLOW. S Lin, J Chen, JA Logemann, PJ Kahrilas. Depamnents of Medicine and Communication Sciences &Disorders, Northwestern'University, Chicago, IL. The pharynx makeg adaptations of timing and intraluminal dimensions to adjust for bolus volume during sw~low. We studied the relationship among mechanics of the swallow, hypo~haryngeal dimensions; and pharyngeal expulsion. Methods: Dynamic (0.07s intervals) 3D reconstructions of deglutitive pharyngdal configuration Qere made using biplane fluoroscopy and ultrafast CT data in a computer model~g environment (wavefront advanced visualizer). Dimensions of themodel were adjusted to measured values from biplane videofluomscopy studies of 8 normal subjects during 1 & 20ml swallows. Cross sectional areas at the valleculae and UES were computed with the analysis feature of the modeling software. Intraluminal pharyngeal volumes above each of structure were similarly computed at 0.07s intervals to quantify flow rate past each structure. Cross sectional areas and flow rates were plotted relative to UES opening (time 0), tongue loading (TL=first glossopalatal opening to max opening), tongue pulsion (TP=max glossopalatal opening to closure), and pharyngeal clearance (PC). Results: Maximal oropharyngeal volumes were 16 and 38 ml for 1 & 20 ml swallows respectively. Maximal luminal dimensions and flow rate were achieved during TP (Figure). Maximal flow rate at each level was similar among volumes suggesting that these areas expand in a compliant fashion. TL
TP
PC
[ 4 1 mlSwallow r z~ 20mlSwallow[
~-,_-':=~Z'~-'-z.-:_~ ~_.7A
, *',* ~
-. ....
' m" 20 ml Swall°w [ Jl~/°~ . ii, c:l Vallecula
!40~
20
o
.
-0.4 -0.2
0 0.2 0.4 0.6 Time in Seconds
.
.
0.8 -0.4 -0.2
.
.
.
k. .....
0 0.2 0.4 0.6 Time in Seconds
10
0.8
Conclusions: 1) Maximal flow from the pharynx and hypopharynx occur during tongue pulsion, prior to the propagated pharyngeal contraction, 2) The hypopharynx distends in a dependent, highly compliant fashion such that flow per unit of cross sectional area is preserved among bolus volumes.
• DO GASTRIC MYOELECTRICAL ABNORMALITIES PREDICT DELAYED GASTRIC EMPTYING? Z.Y, Lin, J. Pan, R.W. McCallum, J.D.Z. Chen. Dept of Medicine, University of Virginia, Charlottesville, VA Coordinated gastric contractions are a necessary condition of normal gastric emptying. Abnormal gastric motility results in delayed gastric emptying. Since gastric motility is controlled by gastric myoelectrical activity it was hypothesized that gastric myoelectrical abnormalities predict delayed gastric emptying. Methods: Ninety seven patients (pts) with symptoms suggestive of gastroparesis who underwent a radionuclide gastric emptying (GE) study participated in this study. Gastric myoeleetrical activity was measured using electrogastrography (EGG)~ After a fast of 6 hrs or more bipolar electrodes were placed on the abdomen and connected to an ambulatory EGG recording unit (Digitrapper EGG, Synectics, Irving, TX). The EGG recording was made for 30 rain in the fasting state and for 2 hours simultaneously with gastric emptying monitoring after an isotopelabelled beefstew meal. Gastric emptying and EGGs were analyzed separately by different investigators. Gastric emptying was defined as abnormal if the gastric retention at 2 hrs was more than 70% or the T1/2 was longer than 150 min. The following EGG parameters were analyzed: 1) 5P, the difference of EGG power at the dominant frequency after and before the meal; 2) the percentage of 2-4 cycles/min (cpm) waves in the fasting and fed state. Results: 1) Sixteen pts showed a decrease in EGG peak power after the meal and 75 % of them had abnormal GE; 2) Twenty seven pts had a dysrhythmic postprandial EGG (percentage of 2-4 cpm waves < 7 0 % ) and 80% o f them had abnormal GE; 3) Seven pts had both a decrease in postprandial EGG power and a dysrhythmic postprandial EGG, and all had abnormal GE; 4) Thirty pts had a dysrhythmic preprandial EGG and 57% of them had abnormal GE. Conclusion: A decrease in postprandial EGG power or a dysrhythmie postprandial EGG (2-4 cpm% < 7 0 % ) is suggestive of delayed gastric emptying. A combination of these two accurately predicts delayed GE. The regularity of the preprandial EGG is however not associated with slow gastric emptying. (supported by a grant from the Whitaker Foundation)
REVELATIONS OF THE LOWER ESOPHAGEAL SPHINCTER FROM THE INTRALUMINAL ULTRASOUND IMAGES. J Liu, V.K. Parashar, R.K. Mittal. From the Dept. o f Med., Univ. o f Virginia HSC, Charlottesville, Virginia 22908.
ANORECTAL FUNCTION IN PROGRESSIVE SYSTEMIC SCLEROSIS:
Backeround: Recent studies indicate that there is an excellent correlation between the histology and the high frequency ultrasound images as regards to the identification of the circular muscle (CM) and longitudinal muscle (LM) layers of the esophagus. We studied 10 normal subjects to ~ w e r the following questions: 1; Are the CM and the LM of the lower ~6~hageal sphincter (LES) distinct from those of the esophagus, 2; Is there an axial and circumferential asymmetry of the LES muscles and 3; Is there a correlation between tt~e thickness of CM and LM with the LES pressure? Methods: The LES location and pressure were measured using 5 mm station pull through manometry. The circumferential (360 °) ultrasound images were obtained using a 20 MHz, 2 mm diameter catheter at the same stations as the pressure. The data were obtained before and after atropine (15 #gms/kg). The thickness of CM and CM layers were measured in mm using a computer and software. Results: The CM and LM at LES level were thicker than those of the esophagus. The region of the thickest muscle corresponded with the peak pressures in the LES. There was an axial and circumferential asymmetry of the CM and LM in the LES, with the thickest muscle being in the middle. The shape of the LES was ellipsoidal rather than circular. Atropine decreased LES pressure and thickness of LES, CM and LM.
charac~fised by smooth muscle atrophy and fibrosis.The aim of tiffsstudy was to investigam anorectal function in paaents with PSS. Since esophageal motor disorder is the most common gasn'ointesfiaalmamfestation in PSS, esophageal manometry was used to assess 8asm)inteslinal involvement. Accordingly, results
Thickness of LES and esophageal CM and LM in mm * P < 0.01,
~'P< 0.05
(LES) CM
(LES) L M
(ESO) CM
(ESO) L M
Control
1,564-0.5S*
1.014-0.51t
0.504- 0.11"
0.34 4- 0.10
Atroplno
1.09 + 0.32
0.71 + 0.29
0.34 4- 0.I0
0.29 4- 0.09
Conclusions: The muscle thickness changes in a dynamic fashion with the changes in LES pressure. The non circular shape of the LES may contribute to the circumferential asymmetry of the LES pressure.
A639
CORRELATION WITH ESOPHAGEAL DYSFUNCTION?
G, Lock, M. Zeuner, A. Holstcge, B. Lang, L SchOlmerich. Dept. of In, real MedicineI, Universityof Rcgensburg, 93042 Regensburg, Gem~ny. Gastrointestinal involvement of pmgressive systemic sclbrosis (PSS) is
of anorec~ manomeW/ were compared in patients with normal and disturbed esophageal function. Methods: 25 patients (22 f,, 3 n~ 17-77 yrs, mean age 56 yrs) with PSS (17 x diffuse type of PSS, 6 x CREST-syndrome, 2 x overlap syndrome with predominance of PSS) were prospectively enrolled in the study from 1992 to 1994. All patients were rcfferrcdfor manometric assessment of
esophageal function; none of the patients had originally been sent for evaluationof fecal incontinence"Esophageal manometry was performed with an eight-lumen water perf,ased polyethyleneprobe (Syne~ncs Medical). Esophageal functionwas judged abnormal when there was aperistalsisof the lower two thirds of the
esophageal body. In anomcml manometry, anal resting pressur~ and maximal squcezc pressure were recorded with an 8 lumen water peffused eathe~. Rectal perception flm~sholdand threshold and elicitabili~ of rectoanal inixibimryreflex (RAIR) were demrmmed by msufll~on of a balloon attached to the tip of the )robe. Results: (median and ranse) Patients with Pa~iemswith normal esophageal disturbed eenplmmotility (n = 8) genl motility(n = 17} Fecal incontinence 0 2 Anal res6ng pressure (ram Pig) 61 (35 - 121) 65 (27 - 96) Max. squeeze pressure (ram Hg) 159 (64 - 254) 182 (63 - 315) Perception threshold (rid) 20 (12 - 25) 20 (10 - 50) ElicitabilRyof RAIR 6/8 (75%) 16/17 (94%) Threshold of RAIR (rrd) 20 (10 - 60) 20 (10 - 50) Amplitude of RAIR (% of 50 (38 - 60) 60 (33 - 88) res~ff pressure) Conclusions: Patients with PSS may suffer from fecal inconuaence, but it ts a rare symptom in an unselcea~d group of patients. There was no significant di~erence in anoh:~al function in P$S panents with normal or disturbed esophagc~ motility; thus, anorectal manomc~ cannot differennam betw~n patients with and without gastTommstmalinvolvementof PSS. In e n ~ to other observations, RAIR was clicimblc in nearly 90% of our patients.
Motility and Nerve-Gut Interactions
• HYPOPHARYNGEAL COMPLIANCE AMONG BOLUS VOLUMES REGULATES OUTFLOW DURING SWALLOW. S Lin, J Chen, JA Logemann, PJ Kahrilas. Depamnents of Medicine and Communication Sciences &Disorders, Northwestern'University, Chicago, IL. The pharynx makeg adaptations of timing and intraluminal dimensions to adjust for bolus volume during sw~low. We studied the relationship among mechanics of the swallow, hypo~haryngeal dimensions; and pharyngeal expulsion. Methods: Dynamic (0.07s intervals) 3D reconstructions of deglutitive pharyngdal configuration Qere made using biplane fluoroscopy and ultrafast CT data in a computer model~g environment (wavefront advanced visualizer). Dimensions of themodel were adjusted to measured values from biplane videofluomscopy studies of 8 normal subjects during 1 & 20ml swallows. Cross sectional areas at the valleculae and UES were computed with the analysis feature of the modeling software. Intraluminal pharyngeal volumes above each of structure were similarly computed at 0.07s intervals to quantify flow rate past each structure. Cross sectional areas and flow rates were plotted relative to UES opening (time 0), tongue loading (TL=first glossopalatal opening to max opening), tongue pulsion (TP=max glossopalatal opening to closure), and pharyngeal clearance (PC). Results: Maximal oropharyngeal volumes were 16 and 38 ml for 1 & 20 ml swallows respectively. Maximal luminal dimensions and flow rate were achieved during TP (Figure). Maximal flow rate at each level was similar among volumes suggesting that these areas expand in a compliant fashion. TL
TP
PC
[ 4 1 mlSwallow r z~ 20mlSwallow[
~-,_-':=~Z'~-'-z.-:_~ ~_.7A
, *',* ~
-. ....
' m" 20 ml Swall°w [ Jl~/°~ . ii, c:l Vallecula
!40~
20
o
.
-0.4 -0.2
0 0.2 0.4 0.6 Time in Seconds
.
.
0.8 -0.4 -0.2
.
.
.
k. .....
0 0.2 0.4 0.6 Time in Seconds
10
0.8
Conclusions: 1) Maximal flow from the pharynx and hypopharynx occur during tongue pulsion, prior to the propagated pharyngeal contraction, 2) The hypopharynx distends in a dependent, highly compliant fashion such that flow per unit of cross sectional area is preserved among bolus volumes.
• DO GASTRIC MYOELECTRICAL ABNORMALITIES PREDICT DELAYED GASTRIC EMPTYING? Z.Y, Lin, J. Pan, R.W. McCallum, J.D.Z. Chen. Dept of Medicine, University of Virginia, Charlottesville, VA Coordinated gastric contractions are a necessary condition of normal gastric emptying. Abnormal gastric motility results in delayed gastric emptying. Since gastric motility is controlled by gastric myoelectrical activity it was hypothesized that gastric myoelectrical abnormalities predict delayed gastric emptying. Methods: Ninety seven patients (pts) with symptoms suggestive of gastroparesis who underwent a radionuclide gastric emptying (GE) study participated in this study. Gastric myoeleetrical activity was measured using electrogastrography (EGG)~ After a fast of 6 hrs or more bipolar electrodes were placed on the abdomen and connected to an ambulatory EGG recording unit (Digitrapper EGG, Synectics, Irving, TX). The EGG recording was made for 30 rain in the fasting state and for 2 hours simultaneously with gastric emptying monitoring after an isotopelabelled beefstew meal. Gastric emptying and EGGs were analyzed separately by different investigators. Gastric emptying was defined as abnormal if the gastric retention at 2 hrs was more than 70% or the T1/2 was longer than 150 min. The following EGG parameters were analyzed: 1) 5P, the difference of EGG power at the dominant frequency after and before the meal; 2) the percentage of 2-4 cycles/min (cpm) waves in the fasting and fed state. Results: 1) Sixteen pts showed a decrease in EGG peak power after the meal and 75 % of them had abnormal GE; 2) Twenty seven pts had a dysrhythmic postprandial EGG (percentage of 2-4 cpm waves < 7 0 % ) and 80% o f them had abnormal GE; 3) Seven pts had both a decrease in postprandial EGG power and a dysrhythmic postprandial EGG, and all had abnormal GE; 4) Thirty pts had a dysrhythmic preprandial EGG and 57% of them had abnormal GE. Conclusion: A decrease in postprandial EGG power or a dysrhythmie postprandial EGG (2-4 cpm% < 7 0 % ) is suggestive of delayed gastric emptying. A combination of these two accurately predicts delayed GE. The regularity of the preprandial EGG is however not associated with slow gastric emptying. (supported by a grant from the Whitaker Foundation)
REVELATIONS OF THE LOWER ESOPHAGEAL SPHINCTER FROM THE INTRALUMINAL ULTRASOUND IMAGES. J Liu, V.K. Parashar, R.K. Mittal. From the Dept. o f Med., Univ. o f Virginia HSC, Charlottesville, Virginia 22908.
ANORECTAL FUNCTION IN PROGRESSIVE SYSTEMIC SCLEROSIS:
Backeround: Recent studies indicate that there is an excellent correlation between the histology and the high frequency ultrasound images as regards to the identification of the circular muscle (CM) and longitudinal muscle (LM) layers of the esophagus. We studied 10 normal subjects to ~ w e r the following questions: 1; Are the CM and the LM of the lower ~6~hageal sphincter (LES) distinct from those of the esophagus, 2; Is there an axial and circumferential asymmetry of the LES muscles and 3; Is there a correlation between tt~e thickness of CM and LM with the LES pressure? Methods: The LES location and pressure were measured using 5 mm station pull through manometry. The circumferential (360 °) ultrasound images were obtained using a 20 MHz, 2 mm diameter catheter at the same stations as the pressure. The data were obtained before and after atropine (15 #gms/kg). The thickness of CM and CM layers were measured in mm using a computer and software. Results: The CM and LM at LES level were thicker than those of the esophagus. The region of the thickest muscle corresponded with the peak pressures in the LES. There was an axial and circumferential asymmetry of the CM and LM in the LES, with the thickest muscle being in the middle. The shape of the LES was ellipsoidal rather than circular. Atropine decreased LES pressure and thickness of LES, CM and LM.
charac~fised by smooth muscle atrophy and fibrosis.The aim of tiffsstudy was to investigam anorectal function in paaents with PSS. Since esophageal motor disorder is the most common gasn'ointesfiaalmamfestation in PSS, esophageal manometry was used to assess 8asm)inteslinal involvement. Accordingly, results
Thickness of LES and esophageal CM and LM in mm * P < 0.01,
~'P< 0.05
(LES) CM
(LES) L M
(ESO) CM
(ESO) L M
Control
1,564-0.5S*
1.014-0.51t
0.504- 0.11"
0.34 4- 0.10
Atroplno
1.09 + 0.32
0.71 + 0.29
0.34 4- 0.I0
0.29 4- 0.09
Conclusions: The muscle thickness changes in a dynamic fashion with the changes in LES pressure. The non circular shape of the LES may contribute to the circumferential asymmetry of the LES pressure.
A639
CORRELATION WITH ESOPHAGEAL DYSFUNCTION?
G, Lock, M. Zeuner, A. Holstcge, B. Lang, L SchOlmerich. Dept. of In, real MedicineI, Universityof Rcgensburg, 93042 Regensburg, Gem~ny. Gastrointestinal involvement of pmgressive systemic sclbrosis (PSS) is
of anorec~ manomeW/ were compared in patients with normal and disturbed esophageal function. Methods: 25 patients (22 f,, 3 n~ 17-77 yrs, mean age 56 yrs) with PSS (17 x diffuse type of PSS, 6 x CREST-syndrome, 2 x overlap syndrome with predominance of PSS) were prospectively enrolled in the study from 1992 to 1994. All patients were rcfferrcdfor manometric assessment of
esophageal function; none of the patients had originally been sent for evaluationof fecal incontinence"Esophageal manometry was performed with an eight-lumen water perf,ased polyethyleneprobe (Syne~ncs Medical). Esophageal functionwas judged abnormal when there was aperistalsisof the lower two thirds of the
esophageal body. In anomcml manometry, anal resting pressur~ and maximal squcezc pressure were recorded with an 8 lumen water peffused eathe~. Rectal perception flm~sholdand threshold and elicitabili~ of rectoanal inixibimryreflex (RAIR) were demrmmed by msufll~on of a balloon attached to the tip of the )robe. Results: (median and ranse) Patients with Pa~iemswith normal esophageal disturbed eenplmmotility (n = 8) genl motility(n = 17} Fecal incontinence 0 2 Anal res6ng pressure (ram Pig) 61 (35 - 121) 65 (27 - 96) Max. squeeze pressure (ram Hg) 159 (64 - 254) 182 (63 - 315) Perception threshold (rid) 20 (12 - 25) 20 (10 - 50) ElicitabilRyof RAIR 6/8 (75%) 16/17 (94%) Threshold of RAIR (rrd) 20 (10 - 60) 20 (10 - 50) Amplitude of RAIR (% of 50 (38 - 60) 60 (33 - 88) res~ff pressure) Conclusions: Patients with PSS may suffer from fecal inconuaence, but it ts a rare symptom in an unselcea~d group of patients. There was no significant di~erence in anoh:~al function in P$S panents with normal or disturbed esophagc~ motility; thus, anorectal manomc~ cannot differennam betw~n patients with and without gastTommstmalinvolvementof PSS. In e n ~ to other observations, RAIR was clicimblc in nearly 90% of our patients.