Role of autonomic dysfunction in patients with functional dyspepsia

BACKGROUND

The role of autonomic dysfunction in patients with functional dyspepsia is not completely understood.

AIMS

1. to prospectively assess abnormalities of autonomic function in patients with functional dyspepsia, 2. to assess whether autonomic dysfunction in these patients is associated with a. visceral hypersensitivity or b. delayed gastric emptying or c. severity of dyspeptic symptoms.

PATIENTS

A series of 28 patients with functional dyspepsia and 14 healthy volunteers without gastrointestinal symptoms were studied.

METHODS

All patients and controls were submitted to a battery of five standard cardiovascular autonomic reflex tests, dyspeptic questionnaire, gastric barostat tests and gastric emptying tests.

RESULTS

1. Autonomic function tests showed that both sympathetic and parasympathetic scores of dyspeptic patients were significantly higher than in controls; 2. visceral hypersensitivity was confirmed in dyspeptics in response to proximal gastric distension, demonstrating lower pain threshold; 3. delayed gastric emptying occurred more frequently in patients with functional dyspepsia than in controls; 4. epigastric pain and epigastric burning were significantly more prevalent in patients with definite evidence of autonomic dysfunction; 5. No significant association was found between presence of autonomic dysfunction and presence of visceral hypersensitivity or presence of delayed gastric emptying in patients with functional dyspepsia.

CONCLUSIONS

We concluded that a possible role of autonomic dysfunction in eliciting dyspeptic symptoms could not be determined from alterations in visceral hypersensitivity or delayed gastric emptying. Autonomic dysfunction might not be the major explanation for symptoms associated with functional dyspepsia.

Effect of subtotal colectomy on gastric emptying of a solid meal in slow-transit constipation

BACKGROUND

Idiopathic slow-transit constipation is considered a panenteral disease in which patients may have delayed gastric emptying. The effects of total abdominal colectomy and ileorectal anastomosis on upper gut motility are unknown. The aim of this study was to evaluate gastric emptying in patients with idiopathic slow-transit constipation before and after subtotal colectomy.

METHODS

Gastric emptying of a solid meal was studied by scintigraphic technique in 11 patients with idiopathic slow-transit constipation. The total colonic transit time was more than 72 hours in all patients studied, with delay in transit in all segments of the colon. The gastric emptying test was repeated 3 to 6 months after total abdominal colectomy and ileorectal anastomosis in ten of these patients. Before and after surgery, patients filled out a questionnaire to record upper gut symptoms.

RESULTS

Solid gastric emptying was delayed (T1/2 > upper limit of normal) in 7 of 11 patients with idiopathic slow-transit constipation. Gastric emptying T1/2 was almost similar before and after surgery. Mean +/- standard deviation was 142 +/- 91 minutes before surgery and 146 +/- 67 minutes after surgery. Symptoms of vomiting and belching improved significantly after surgery. Symptoms of nausea, bloating, and pyrosis also decreased, but these changes failed to reach statistical significance.

CONCLUSION

Despite a reduction in upper gut symptoms, total abdominal colectomy and ileorectal anastomosis does not improve delayed gastric emptying in patients with idiopathic slow-transit constipation.

Changes of gallbladder and gastric dynamics in patients with acute hepatitis A

Transient alterations of gallbladder morphology and dynamics have been reported in patients with during acute hepatitis A. The presence of dyspepsia also suggests involvement of gastric motility. During a 60-day follow-up, we investigated gallbladder and gastric motility in relation to dyspepsia in acute viral hepatitis A patients. Twenty patients were assessed at referral (day 0) and at days 7, 21, 42 and 60 and compared with 20 healthy volunteers. Gallbladder morphology and motility and gastric motility were assessed in the fasting and postprandial period by functional ultrasonography using a liquid test meal. Dyspeptic symptoms were scored. At day 0, fasting gallbladder volume was 5.9 +/- 1.3 mL, 32.6 +/- 4.6 mL, and 21.5 +/- 1.9 mL (mean +/- SE) in patients with gallbladder sludge (n = 7), without sludge (n = 13) and controls, respectively (P < 0.05 in sludge vs. no sludge and controls; P < 0.05 in no sludge vs. controls, ANOVA). Small fasting gallbladder volume in patients with sludge increased and sludge disappeared within 7 days. At day 0, patients with sludge also had increased thickness of fasting gallbladder wall and increased serum transaminase levels compared with patients without sludge and controls. Gallbladder contraction was similar in patients and controls. However, patients had delayed gastric emptying, which positively correlated with dyspepsia score. Gallbladder morphological changes observed in the acute phase of hepatitis A are transient and are associated with hepatocellular damage. Gastric emptying is delayed during the first week of disease and is associated with dyspeptic symptoms.

Cisapride improves gallbladder emptying and bile lipid composition in patients with gallstones

BACKGROUND AND AIM

Biliary cholesterol supersaturation, gallbladder stasis and delayed intestinal transit are the key events in cholesterol gallstone formation. We studied the effect of cisapride, a prokinetic drug, on gallbladder emptying and bile composition in patients with gallstone disease undergoing cholecystectomy.

METHODS

Gallbladder emptying, cholesterol saturation index (CSI) and nucleation time were studied in 21 patients with gallstone disease. Eleven patients (cisapride group, age 41.9 +/- 2.9 years) received tablet cisapride 10 mg t.i.d. for 2 weeks, while 10 patients (placebo group, age 42.1 +/- 1.9 years) received placebo for the same duration. Gallbladder emptying was repeated in all patients after a 2-week treatment with cisapride or placebo. Gallbladder bile was obtained at the time of surgery for the measurement of CSI and nucleation time.

RESULTS

Residual volume of the gallbladder decreased (mean +/- SE, 18.6 +/- 2.5 mL vs 10.0 +/- 1.1 mL, P = 0.007), and the ejection fraction increased (43.5 +/- 5.3% vs 60.0 +/- 3.2%, P = 0.007) in patients in the cisapride group, while no change was observed in placebo group patients. Nucleation time was higher in the cisapride group than in the placebo group (14.9 +/- 1.3 days vs 8.0 +/- 0.9 days, P = 0.003). Patients in the cisapride group had a significantly lower cholesterol concentration (molar percentage, 5.1 +/- 0.3% vs 6.8 +/- 0.8%, P = 0.049) and CSI (1.0 +/- 0.1 vs 1.36 +/- 0.11, P = 0.034) than patients in the placebo group.

CONCLUSION

Cisapride improves gallbladder emptying and bile lithogenicity in patients with gallstone disease.

Colchicine for persistent constipation after total abdominal colectomy with ileorectostomy for colonic inertia

Severe constipation caused by colonic inertia may be associated with a generalized gastrointestinal dysmotility syndrome. Patients with severe constipation pose a significant challenge in terms of management. Failure of medical therapy usually leads to surgery in the form of a subtotal colectomy. Most patients develop diarrhea after the surgery, but a subgroup of patients continue to experience constipation. We report the case of such a patient who underwent a total abdominal colectomy and ileorectostomy for intractable constipation. He continued to have constipation after the surgery that was responsive only to a gallon of bowel-cleansing solution. A treatment trial of colchicine was partially unsuccessful when used on its own, but a combination of colchicine and a lesser dose of Colyte was found to be effective in maintaining regular bowel movements.

Slow transit constipation

Slow transit constipation is a clinical syndrome predominantly affecting young women, characterized by constipation and delayed colonic transit, occasionally associated with pelvic floor dysfunction. The disorder spans a spectrum of variable severity, ranging from patients who have relatively mild delays in transit but who are otherwise indistinguishable from irritable bowel syndrome patients at one extreme, to patients with colonic inertia or chronic megacolon at the other extreme. Potential mechanisms for impaired colonic propulsion include fewer colonic HAPCs or a reduced colonic contractile response to a meal. The cause of the syndrome is unclear. The treatment is primarily medical; surgery is reserved for patients with severe disease or colonic inertia. Recognition and treatment of pelvic floor dysfunction is crucial for patients treated medically or surgically. Collaborative studies are necessary to determine the pathophysiology of this disorder and to ascertain the efficacy of novel prokinetic agents.

The effect of acute oral erythromycin on gallbladder motility and on upper gastrointestinal symptoms in gastrectomized patients with and without gallstones: a randomized, placebo-controlled ultrasonographic study

OBJECTIVE

Gastrectomy might be a risk factor for cholelithiasis and gallbladder stasis might play a major role. We studied fasting and postprandial gallbladder motility with 600 mg oral erythromycin or placebo in gastrectomized patients (with and without gallstones) and controls.

METHODS

Seventeen patients operated on for gastric cancer (subtotal gastrectomy: n = 10, total gastrectomy: n = 7) were compared with 20 sex- and body-size matched healthy controls. Subjects randomly received erythromycin or placebo 30 min before the ingestion of a standard 200 ml liquid test meal. Gallbladder volume was estimated by ultrasonography until 120 min after test meal. A visual analog scale monitored GI perception of appetite, satiety, nausea, abdominal fullness and epigastric pain.

RESULTS

Gastrectomized patients had increased fasting gallbladder volume (35.9 +/- 3.4 ml versus 21.0 +/- 1.4 ml, p = 0.0005) with faster postmeal emptying (T/2 14.8 +/- 1.1 min versus 23.5 +/- 1.5 min, p = 0.00019) than controls. Six patients developed small and asymptomatic gallstones, which did not influence gallbladder motility. In these patients, fasting gallbladder volume increased with time after surgery (r = +0.82, p = 0.047). Perception of satiety, abdominal fullness, and epigastric pain after ingestion of the test meal were all significantly greater in patients than in controls. Erythromycin significantly enhanced gallbladder emptying during fasting (p = 0.001) and postprandially in both patients and controls (0.002 < p < 0.017) and significantly reduced postmeal satiety and epigastric discomfort in gastrectomized patients.

CONCLUSIONS

Increased fasting volume might be a form of stasis, predisposing patients to gallstone formation. Erythromycin improves fasting and postprandial gallbladder emptying and decreases upper GI symptoms in gastrectomized patients.

Approach to patients with refractory constipation

Constipation is a very frequent problem, particularly in elderly patients. Constipation is a common reason for patients to seek medical advice, and it accounts for a large number of different prescription and over-the-counter medications. In many cases, no definite cause can be found. Most patients respond to conservative therapy with increased fiber and fluid intake alone. Patients with constipation that is more difficult to control or with alarm symptoms (eg, blood in stool, sudden onset, weight loss, or decreasing stool caliber) warrant further investigation. A variety of medical, behavioral, and surgical therapies can be employed to help these more refractory patients.

Elevated cholesterol metabolism and bile acid synthesis in mice lacking membrane tyrosine kinase receptor FGFR4

Heparan sulfate-regulated transmembrane tyrosine kinase receptor FGFR4 is the major FGFR isotype in mature hepatocytes. Fibroblast growth factor has been implicated in the definition of liver from foregut endoderm where FGFR4 is expressed and stimulation of hepatocyte DNA synthesis in vitro. Here we show that livers of mice lacking FGFR4 exhibited normal morphology and regenerated normally in response to partial hepatectomy. However, the FGFR4 (-/-) mice exhibited depleted gallbladders, an elevated bile acid pool and elevated excretion of bile acids. Cholesterol- and bile acid-controlled liver cholesterol 7alpha-hydroxylase, the limiting enzyme for bile acid synthesis, was elevated, unresponsive to dietary cholesterol, but repressed normally by dietary cholate. Expression pattern and cholate-dependent, cholesterol-induced hepatomegaly in the FGFR4 (-/-) mice suggested that activation of receptor interacting protein 140, a co-repressor of feed-forward activator liver X receptor alpha, may mediate the negative regulation of cholesterol- and bile acid-controlled liver cholesterol 7alpha-hydroxylase transcription by FGFR4 and cholate. The results demonstrate that transmembrane sensors interface with metabolite-controlled transcription networks and suggest that pericellular matrix-controlled liver FGFR4 in particular may ensure adequate cholesterol for cell structures and signal transduction.

Review article: in vitro studies of gall-bladder smooth muscle function. Relevance in cholesterol gallstone disease

The interplay between contraction and relaxation in the gall-bladder muscularis leads to appropriate gall-bladder emptying and refilling during fasting and in the postprandial state in vivo. Several studies in both human and animal models have focused on cellular and molecular events in the gall-bladder wall in health and disease in vitro. Principal methods to study gall-bladder smooth muscle function include receptor binding studies (at the level of plasmamembranes or histological sections), phase contrast microscopy (at the level of isolated smooth muscle cells), and tensiometry (at the level of smooth muscle strips or the whole gall-bladder). At a very early stage, cholesterol gallstone disease is characterized by exposure of the gall-bladder wall to excess of biliary cholesterol and the cytotoxic effect of the bile salt deoxycholate. On a long-term basis, a form of gall-bladder leiomyopathy develops with defects involving the mechanisms of signal transduction at the level of plasmamembranes. The end-stage result is pathological contraction and/or relaxation of smooth musculature, impaired gall-bladder motility and gall-bladder stasis, all key factors in the pathogenesis of biliary cholesterol crystallization and gallstones.

Review article: agents affecting gall-bladder motility--role in treatment and prevention of gallstones

Various agents may either enhance or impair post-prandial gall-bladder motility, and they are identified in this review. When studying the impact of medication on gall-bladder motility, the effects on interdigestive gall-bladder and intestinal motility should also be taken into account. Patients at high risk of gallstone disease, and patients who are treated chronically with gall-bladder motility inhibiting drugs, may benefit from improved gall-bladder motility using a prokinetic agent. However, there are no long-term studies to prove that such a strategy prevents gallstone formation.

Gallbladder motility and cholesterol crystallization in bile from patients with pigment and cholesterol gallstones

BACKGROUND

Little is known about gallbladder motility in patients with black pigment stones when compared to cholesterol gallstone patients, or about their relationship to biliary composition, crystallization and stone characteristics.

DESIGN

Fasting and postprandial gallbladder volumes were studied by ultrasonography in 49 gallstone patients with pigment (n = 14) or cholesterol (n = 35) stones and 30 healthy controls. After cholecystectomy stone composition, gallbladder wall inflammation, cholesterol saturation index and appearance of platelike cholesterol crystals in bile were evaluated in gallstone patients.

RESULTS

Fasting gallbladder volume was significantly (P < 0.05) increased in cholesterol stone patients (31.7 +/- 1.9 mL) but not in pigment stone patients (21.9 +/- 3.1 mL), compared to controls (21.0 +/- 1.5 mL). Postprandial emptying was delayed in patients (half-emptying time: 31 +/- 2 min, 35 +/- 3 min, 24 +/- 2 min in cholesterol stone patients, pigment stone patients and controls, respectively, P < 0.05) and incomplete (residual volume: 43.2 +/- 2.7%, 40.0 +/- 4.3%, 15.8 +/- 1.6% min in cholesterol stone patients, pigment stone patients and controls, respectively, P < 0.05). The inflammation of the gallbladder wall was mild or absent in all cases. Biliary cholesterol saturation index was 152.3 +/- 8.5% and 92.9 +/- 4.8% in patients with cholesterol and pigment stones, respectively (P < 0.01). Whereas cholesterol crystals never appeared during 21 days in biles from patients with pigment stones, crystal observation time in patients with cholesterol gallstone was 5 days (median) and was significantly shorter in patients with multiple (4 days) than in patients with solitary (12 days) cholesterol stones (P = 0.0019).

CONCLUSIONS

Patients with black pigment stones who do not have excess cholesterol and do not grow cholesterol crystals in bile have decreased gallbladder emptying, although to a lesser extent than patients with cholesterol stones. Thus, gallbladder stasis is likely to put a subset of subjects at risk for the formation of pigment gallstones, and pathogenic mechanisms need to be further investigated.

Standards for diagnosis of gastrointestinal motility disorders. Section: ultrasonography. A position statement from the Gruppo Italiano di Studio Motilità Apparato Digerente

Ultrasonography is a non-invasive, relatively easy, validated and reproducible technique. We assessed the usefulness of functional ultrasonography to study disorders of gastro-oesophageal tract, gallbladder and pancreatic duct. Oesophagus Oesophagus and the gastro-oesophageal junction can be visualized in children up to 5 years old. Ultrasonography shows 100% sensitivity and 87.5% specificity compared to ambulatory pH-metry for gastro-oesophageal reflux disease diagnosis. Stomach Ultrasonography can be used to estimate whole gastric volume, antral area or diameters, antro-pyloric volume, transpyloric flow in fasting state and in response to test meal. Gallbladder Ultrasonography is reliable to estimate volume in fasting state and in response to test meal or exogenous stimulus. For both stomach and gallbladder, indications might include the study of healthy subjects and of pathophysiologically relevant conditions such as dysmotility-like dyspepsia, suspicion of delayed gastric emptying, diabetes mellitus, gallstone disease and effect of drugs either delaying or accelerating motility. Common bile duct Ultrasonography can be used to estimate interprandial and postprandial common bile duct diameter in patients with clinical suspicion of common bile duct obstruction in fasting state and in response to test meal or exogenous stimuli. Although functional ultrasonography is used mainly for research purposes, its simplicity makes it appealing for clinical use to assess gastrointestinal motility in health and disease.

Overweight, but not high dietary fat intake, increases risk of gastroesophageal reflux disease hospitalization: the NHANES I Epidemiologic Followup Study. First National Health and Nutrition Examination Survey

PURPOSE

Gastroesophageal reflux disease is an important and increasingly common condition. Both overweight and high fat food consumption have been implicated as causes of reflux disease. We examined the relationship of overweight, high dietary fat intake, and other factors with reflux disease hospitalization.

METHODS

We studied participants in the first National Health and Nutrition Examination Survey, a population-based sample examined in 1971-75 and followed through 1992-93. Persons with a physician-diagnosed hiatal hernia at baseline or reflux disease hospitalization within the first five years of study were excluded. A second analysis included follow-up of 9851 participants free of reflux disease in 1982-84. Ninety-six percent of the baseline cohort were recontacted. Reflux disease cases were persons hospitalized with a diagnosis of esophagitis or uncomplicated hiatal hernia. Hazard rate ratios for reflux disease hospitalization according to body mass index (BMI) (kg/m2), total daily servings of high fat foods and other factors were calculated using Cox proportional hazards analysis.

RESULTS

A total of 12,349 persons were followed for a median of 18.5 years (range 5.0-22.1). Cumulative incidence of reflux disease hospitalization was 5.2% at 20 years. Multivariate survival analysis revealed higher reflux disease hospitalization rates with higher BMI (5 kg/m2) [hazard ratio (HR) = 1.22, 95% confidence interval (CI) = 1.13-1.32]. No relationship was found between higher fat intake and reflux disease hospitalization. Other factors associated with reflux disease hospitalization included age, low recreational activity, and history of doctor-diagnosed arthritis.

CONCLUSIONS

Overweight, but not high dietary fat intake, increases risk of gastroesophageal reflux disease hospitalization.

Gallstones: an intestinal disease?

Current evidence suggests that impaired intestinal motility may facilitate gallstone formation by influencing biliary deoxycholate levels or by modulating interdigestive gall bladder motility (fig 2), although a primary intestinal defect in gallstone pathogenesis has not yet been demonstrated. In the cold war period, most interesting events, from a political point of view, occurred at the border between capitalist and communist systems, near the iron curtain. Similarly, the gall bladder and biliary tract can be viewed as the border between liver and intestinal tract, where many interesting things occur with profound impact on both systems. Combined efforts by researchers in the field of hepatology and gastrointestinal motility should brake down the Berlin wall of ignorance of one of the most common diseases in the Western world.

Slow-transit constipation: solitary symptom of a systemic gastrointestinal disease

INTRODUCTION

Autonomic neuropathy is thought to play a role in the pathogenesis of slow-transit constipation, but other gastrointestinal organs may also be involved, even if they are symptom-free. We investigated whether motility in gastrointestinal organs other than the colon was impaired in patients with slow-transit constipation and whether the autonomic nervous system was involved.

METHODS

Twenty-one consecutive patients (18 females; median age, 46 years) with severe chronic constipation (< or = 2 defecations/week and delayed colonic transit time) were studied. Autonomic neuropathy function was tested with esophageal manometry, gastric and gallbladder emptying (fasting and postprandial motility) by ultrasonography, orocecal transit time (H2-breath test), colonic transit time (radiopaque markers), and anorectal volumetric manometry. The integrity of the autonomic nervous system was assessed by a quantitative sweat-spot test for preganglionic and postganglionic fibers, tilt-table test, and Valsalva electrocardiogram R-R ratio.

RESULTS

Esophageal manometry showed gastroesophageal reflux or absence of peristalsis in five of the seven patients examined. Gallbladder dysmotility (i.e., increased fasting, postprandial residual volume, or both) was observed in 6 of 14 (43 percent) patients. Gastric emptying was decreased in 13 of 17 (76 percent) patients. Orocecal transit time was delayed in 18 of 20 (90 percent) patients; median transit time was 160 (range, 90-200) minutes. Median colonic transit time was 97 (range, 64-140) hours. Anorectal function showed abnormal rectoanal inhibitory reflex and decreased rectal sensitivity in 11 of 19 (58 percent) patients. Signs of autonomic neuropathy of the sympathetic cholinergic system were found in 14 of 18 (78 percent) patients. Only one of nine patients had vagal abnormalities detected with the Valsalva test and four of five patients with a history of orthostatic hypotension had a positive tilt-table test.

CONCLUSIONS

Slow-transit constipation may be associated with impaired function of other gastrointestinal organs. More than 70 percent of patients with slow-transit constipation present some degree of autonomic neuropathy. Severe constipation may be the main complaint in patients with a systemic disease involving several organs and possibly involving the autonomic nervous system. This should be considered in the management of such cases.

Effects of ursodeoxycholic acid therapy on in vitro gallbladder contractility in patients with cholesterol gallstones

During treatment with ursodeoxycholic acid (UDCA), the fasting gallbladder volume increases by a yet unknown mechanism. The present study tests whether in vitro human gallbladder contractility in response to acetylcholine and cholecystokinin is affected by UDCA therapy. Gallbladder tissue was obtained from 15 patients treated with UDCA (10 mg/kg/day) during three weeks prior to surgery, and from 15 comparable patients not treated. Data were correlated with in vivo contractility, bile composition, and gallbladder wall inflammation. The inflammation score was lower in the treated patient group. UDCA treatment enhanced gallbladder contractility in vitro: Dose-response curves for acetylcholine and cholecystokinin were both shifted to the left, and the maximal contractile stress generated in response to cholecystokinin was higher in the treated group, whereas the maximal acetylcholine-induced stress was not increased. Maximal cholecystokinin-induced stress correlated positively with fasting gallbladder volume and negatively with the biliary cholesterol saturation index, but not with bile salt hydrophobicity or gallbladder wall inflammation score. In conclusion, UDCA treatment improves in vitro gallbladder contractility, possibly related to a reduced biliary cholesterol saturation. Increased fasting gallbladder volumes during UDCA treatment thus do not appear to result from decreased gallbladder muscle contractile strength.

Effects of ursodeoxycholic acid therapy on in vitro gallbladder contractility in patients with cholesterol gallstones

During treatment with ursodeoxycholic acid (UDCA), the fasting gallbladder volume increases by a yet unknown mechanism. The present study tests whether in vitro human gallbladder contractility in response to acetylcholine and cholecystokinin is affected by UDCA therapy. Gallbladder tissue was obtained from 15 patients treated with UDCA (10 mg/kg/day) during three weeks prior to surgery, and from 15 comparable patients not treated. Data were correlated with in vivo contractility, bile composition, and gallbladder wall inflammation. The inflammation score was lower in the treated patient group. UDCA treatment enhanced gallbladder contractility in vitro: Dose-response curves for acetylcholine and cholecystokinin were both shifted to the left, and the maximal contractile stress generated in response to cholecystokinin was higher in the treated group, whereas the maximal acetylcholine-induced stress was not increased. Maximal cholecystokinin-induced stress correlated positively with fasting gallbladder volume and negatively with the biliary cholesterol saturation index, but not with bile salt hydrophobicity or gallbladder wall inflammation score. In conclusion, UDCA treatment improves in vitro gallbladder contractility, possibly related to a reduced biliary cholesterol saturation. Increased fasting gallbladder volumes during UDCA treatment thus do not appear to result from decreased gallbladder muscle contractile strength.

Abdominal symptoms and food intolerance related to gallstones

We have evaluated the association between gallstones and abdominal symptoms, comparing two different study designs. We asked questions on abdominal pain, dyspeptic symptoms, and food intolerance in (1) surgery patients referred for conditions unrelated to gallstones, screened by ultrasound (screening study, n = 892, 63 with gallstones); and in (2) symptomatic patients referred for gallbladder ultrasound (clinical study, n = 336, 71 with gallstones). Gallstones were associated with mid upper abdominal pain in the screening study, and with mid upper abdominal pain, biliary pain, and colic (each independently) in the clinical study. When these symptoms were absent (and only dyspeptic symptoms or food intolerance was present), gallstones were not more common than expected from the general population prevalence (estimated from the screening study). When upper abdominal pain symptoms are accounted for, other symptoms (dyspeptic; food intolerance; pain related to food intake) have no additional diagnostic value. The results are discussed, contrasting different types of studies.

Motilin induces gall bladder emptying and antral contractions in the fasted state in humans

BACKGROUND

Animal studies have shown that motilin affects gall bladder motility. In humans, no effect has been shown, but erythromycin, a motilin receptor agonist, induces gall bladder emptying.

AIMS

To explore the effect of increasing doses of exogenous motilin on gall bladder volume and antral contractility in the fasted state in humans.

METHODS

After an overnight fast, eight healthy men received increasing intravenous doses of Leu13-motilin (KW-5139) or 0.9% NaCl in a double blind, randomised fashion. Gall bladder volume and antral contraction frequency were determined by ultrasonography.

RESULTS

Infusion of motilin increased plasma motilin levels. Motilin induced a reduction in gall bladder volume of 8.0 (5.0)%, 17.1 (5.0)%, 18.5 (4.7)%, and 16.1 (4.9)% of baseline volume at the end of infusion of 2, 4, 8, and 16 pmol/kg/min respectively, compared with mean stable gall bladder volumes during placebo infusion (p < 0.05). Antral contraction frequency increased during motilin infusion, but not during placebo infusion (p < 0.05).

CONCLUSIONS

Exogenous motilin reducted fasting gall bladder volume and increased antral contractions. After reaching maximal reduction, the gall bladder volume did not decrease further during continuous motilin infusion at higher doses and stayed at the same reduced volume. The degree of gall bladder volume reduction during motilin infusion mimicked gall bladder emptying preceding antral phase III activity of the migrating motor complex in humans. This study indicates that motilin may play a physiological role in the regulation of gall bladder emptying in the fasted state.

Gallstone dissolution with oral bile acid therapy. Importance of pretreatment CT scanning and reasons for nonresponse

In patients with cholesterol-rich gallbladder stones and a patent cystic duct, complete stone clearance rates of 65-90% have been reported with oral bile acids (OBAs) alone or with adjuvant lithotripsy (extracorporeal shock-wave lithotripsy; ESWL). The aims of the present study were to analyze pretreatment gallstone characteristics that predict the speed and completeness of dissolution with OBAs +/- ESWL, and to assess, in patients with incomplete dissolution, the reasons for the poor response. We compared pretreatment gallstone characteristics in 43 patients who became stone-free after a median of 9 months OBAs +/- ESWL with those in 43 age- and sex-matched patients whose stones failed to dissolve after two years of treatment. In those with incomplete gallstone dissolution, we repeated the oral cholecystogram and computed tomogram (CT) and, in selected patients, obtained gallbladder bile by percutaneous fine-needle puncture. In patients who became stone-free, those with stones that were isodense with bile and/or had CT scores of < 75 Hounsfield units had the fastest dissolution rates. In the 43 nonresponders, the main causes for treatment failure were impaired gallbladder contractility and acquired stone calcification. CT-lucent, noncholesterol stones, or failure of desaturation of bile with the prescribed bile acids, occurred in a minority. We conclude that the pretreatment CT attenuation score predicts both the speed and completeness of gallstone dissolution. In patients with incomplete stone dissolution, the combination of oral cholecystography, CT, and analysis of gallbladder bile will determine the underlying reasons for treatment failure in most, but not all, cases.

Cholestyramine influences meal-stimulated pancreaticobiliary function and plasma cholecystokinin independent of gastric emptying and food digestion

BACKGROUND

Cholestyramine enhances gallbladder emptying and plasma cholecystokinin responses to oral ingestion of a mixed meal. It is not known whether this effect occurs independently of alterations in gastric emptying or maldigestion of nutrients.

METHODS

We perfused 15 g of an amino acid meal intraduodenally for 60 min in seven healthy volunteers, once with and once without cholestyramine. Intraduodenal perfusion of saline with or without cholestyramine (6 g/h) was started 60 min before the amino acid meal and continued for 2 h.

RESULTS

Cholestyramine markedly enhanced the incremental plasma cholecystokinin response to the meal from 36 +/- 12 to 139 +/- 25 pmol/l x 60 min (P < 0.005), incremental amylase output from 2.4 +/- 0.7 to 5.7 +/- 0.7 kU/h (P < 0.05), and incremental integrated gallbladder contraction from 1948 +/- 235 to 2840 +/- 189% x 60 min (P < 0.05).

CONCLUSION

The enhancing effect of cholestyramine on postprandial gallbladder contraction, pancreatic enzyme secretion, and plasma cholecystokinin release is not dependent on gastric emptying rates or appropriate digestion of nutrients.

Gallstone dissolution with oral bile acid therapy. Importance of pretreatment CT scanning and reasons for nonresponse

In patients with cholesterol-rich gallbladder stones and a patent cystic duct, complete stone clearance rates of 65-90% have been reported with oral bile acids (OBAs) alone or with adjuvant lithotripsy (extracorporeal shock-wave lithotripsy; ESWL). The aims of the present study were to analyze pretreatment gallstone characteristics that predict the speed and completeness of dissolution with OBAs +/- ESWL, and to assess, in patients with incomplete dissolution, the reasons for the poor response. We compared pretreatment gallstone characteristics in 43 patients who became stone-free after a median of 9 months OBAs +/- ESWL with those in 43 age- and sex-matched patients whose stones failed to dissolve after two years of treatment. In those with incomplete gallstone dissolution, we repeated the oral cholecystogram and computed tomogram (CT) and, in selected patients, obtained gallbladder bile by percutaneous fine-needle puncture. In patients who became stone-free, those with stones that were isodense with bile and/or had CT scores of < 75 Hounsfield units had the fastest dissolution rates. In the 43 nonresponders, the main causes for treatment failure were impaired gallbladder contractility and acquired stone calcification. CT-lucent, noncholesterol stones, or failure of desaturation of bile with the prescribed bile acids, occurred in a minority. We conclude that the pretreatment CT attenuation score predicts both the speed and completeness of gallstone dissolution. In patients with incomplete stone dissolution, the combination of oral cholecystography, CT, and analysis of gallbladder bile will determine the underlying reasons for treatment failure in most, but not all, cases.

Increased gall bladder volume in primary sclerosing cholangitis

BACKGROUND

The diagnosis of primary sclerosing cholangitis (PSC) requires invasive procedures such as liver biopsy and endoscopic retrograde cholangiography (ERC). Sonographic measurement of fasting gall bladder volume, which has been reported to be enlarged in PSC, could serve as a non-invasive screening test.

METHODS

Fasting gall bladder volume was studied in patients with PSC (n = 24), primary biliary cirrhosis (PBC, n = 13), liver cirrhosis due to other causes (n = 18), ulcerative colitis (n = 15), and healthy controls (n = 23). Meal induced gall bladder emptying was studied in patients with PSC, patients with PBC, and healthy controls.

RESULTS

In patients with PSC gall bladder volume was greatly enlarged (72.9 (SEM 3.7) ml) compared with healthy controls (25.4 (1.7) ml, and patients with PBC (30.9 (2.7) ml), liver cirrhosis (31.3 (4.0) ml) or ulcerative colitis (25.8 (2.0) ml) (p < 0.0005 v all). In four patients with PSC the gall bladder wall was irregularly thickened (> 4 mm) as previously described in PSC. Postprandial residual fractions (% of fasting volume) were comparable between patients with PSC (17.5 (3.7)%) and those with PBC (23.6 (7.1%) and healthy controls (12.7 (2.3)%) Although gall bladder emptying seems normal, increased biliary pressure in patients with PSC cannot be excluded.

CONCLUSION

Apart from wall thickening, patients with PSC often present with enlargement of the gall bladder. Sonographic determination of fasting gall bladder volume may be a useful, non-invasive, and easy to perform tool in the evaluation of patients suspected of having PSC.

In vitro contractility of stimulated and non-stimulated human gallbladder muscle

In an attempt to define, more clearly, the nature of gallbladder contraction we obtained muscle strips from human gallbladder wall, removed at cholecystectomy. Samples were taken from various areas of the gallbladder to seek evidence of a dominant axis of contraction. The strips were stimulated with increasing concentrations of cholecystokinin-8 (CCK-8) and carbachol, and, to determine maximal contractile force, 0.25 M potassium chloride. No differences were seen between samples taken from the long-itudinal, circular and oblique axes. In a second series of experiments, samples were taken from the body and neck regions of the gallbladder. In these, it was seen that the samples from the body contracted more forcefully than those of the neck tissue and that they were more sensitive to carbachol stimulation. The difference in response to CCK-8 measured in the strips from the body and cystic duct/neck of the gallbladder cannot be explained by a difference in sensitivity to CCK-8, but is mainly due to the difference in the amount of muscle tissue present. Strips from the body are more sensitive to muscarinic stimulation that those from the neck. Overall, there is a functional difference in sensitivity between the body and neck which would serve to facilitate bile flow into the common bile duct during gallbladder contraction.

Cholesterol synthesis inhibitors in cholesterol gallstone disease

Cholesterol synthesis inhibitors (HMG-CoA Reductase Inhibitors) are reported to decrease cholesterol saturation index of duodenal bile in hypercholesterolaemic subjects. The dissolution of gallstones in animals on treatment with these drugs created expectations of a therapeutical role for these drugs in cholesterol gallstone disease. However, in prospective studies with these drugs in humans, no effect on number and size of cholesterol gallstones was observed. This is likely the result of the fact that not just biliary secretion of cholesterol is decreased during treatment with these drugs in cholesterol gallstone disease, but phospholipids and bile salts as well. As a consequence, nucleation time of cholesterol crystals in gallbladder bile is not influenced by these drugs. Another important determinant in cholesterol gallstone disease, e.g. gallbladder motility, is not influenced by HMG-CoA reductase inhibitors. Although these drugs and their metabolites are secreted into the bile, they do not influence biliary lithogenicity. In conclusion, there seems to be no therapeutic role for HMG-CoA reductase inhibitors in the treatment of cholesterol gallstone disease, although no negative effects on determinants of cholesterol gallstone formation during treatment with these drugs are observed either.

Effects of simvastatin and cholestyramine on bile lipid composition and gall bladder motility in patients with hypercholesterolaemia

Although the effects of 3-hydroxy, 3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and bile acid sequestrants on bile lipid composition have been studied separately, no data are available on combination therapy of these drugs. Moreover, the effects of prolonged (four weeks) administration of these drugs on gall bladder motility, an important determinant of cholesterol gall stone formation, have not been studied so far. A prospective study was therefore performed with eight patients who had hypercholesterolaemia (age 53 (5) (SEM), body mass index 27.4 (1.1) kg m-2, low density lipoprotein cholesterol 5.9 (0.3) mmol/l). They received treatment during three periods of four weeks with simvastatin 20 mg/day, cholestyramine 4 g twice daily, and a combination of both in random order, each treatment period separated by a two week wash out period. Before treatment and after each treatment period, postprandial gall bladder motility was studied with ultrasound, followed by duodenal bile sampling. Serum cholesterol decreased in all subjects in any treatment period illustrating good compliance. Molar percentages in duodenal bile of cholesterol, phospholipids, and bile salts were unchanged during simvastatin and cholestyramine treatment. During combined therapy percentage bile salts was lower (72.5 (2.9)% v 77.8 (1.7)% at baseline, p < 0.05) whereas phospholipids were higher (21.2 (2.4)% v 16.4 (1.3)% at baseline, p < 0.05). As a result cholesterol saturation index (CSI) did not change in any treatment period. No cholesterol crystals were detected in any bile sample, taken at baseline and after each treatment period. Bile salt hydrophobicity index during cholestyramine (0.19 (0.02)) and combined treatment (0.22 (0.01)) decreased strongly compared with baseline (0.34 (0.01), p < 0.001, p < 0.01, respectively), resulting from increased proportions of glycocholate (59.4 (3.9)% (cholestyramine), 55.6 (2.4)% (combination), and 28.2 (2.2) (baseline), p < 0.001)) and decreased proportions of deoxycholic acid and chenodeoxycholic acid. Fasting gall bladder volume was increased during simvastatin (28.7 (2.8) ml) v baseline (23.2 (2.3) ml, p < 0.01) whereas, residual volume did not differ (5.7 (0.9) ml (simvastatin) v 5.9 (0.7) (baseline). During cholestyramine and combined treatment, no significant differences in gall bladder motility were seen. In conclusion, this study suggests that HMG-CoA reductase inhibitors alone and combined with cholestyramine do not affect major determinants of cholesterol gall stone formation, for example, CSI and gall bladder emptying. In addition cholestyramine alone and combined with simvastatin leads to a strong decrease of bile salt hydrophobicity, which may be beneficial in the prevention of nucleation of cholesterol crystals.

The effects of the 3-hydroxy, 3-methylglutaryl coenzyme A reductase inhibitor pravastatin on bile composition and nucleation of cholesterol crystals in cholesterol gallstone disease

3-hydroxy,3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors reduce biliary cholesterol saturation index (CSI) in duodenal bile in hypercholesterolemic patients and might be useful for gallstone dissolution. However, preliminary data suggest that these drugs are not effective in this respect. We therefore studied 33 patients with radiolucent gallstones in an opacifying gallbladder who were scheduled for elective cholecystectomy. Patients were treated with 40 mg pravastatin day-1 or placebo during the 3 weeks before surgery. Six patients could not be evaluated. Baseline characteristics (age, sex, body mass index, serum cholesterol, and the solitary/multiple gallstone ratio) were similar in both groups. Serum cholesterol fell by 39% in the pravastatin group (P < .001) and remained unchanged in the placebo group. Biliary cholesterol (9.5 +/- 1.3 vs. 14.3 +/- 1.5 mmol/L, P = .026), and phospholipid concentrations (24.8 +/- 3.9 vs. 36.7 +/- 3.9 mmol/L, P = .043) were lower in the pravastatin group. Although bile salt concentrations were lower in the pravastatin group (114 +/- 21 vs. 152 +/- 15 mmol/L), this difference was not significant. CSI was not different between both groups (142 +/- 27% [pravastatin] vs. 113 +/- 6% [placebo], P = NS). Cholesterol crystals were present in fresh bile in 7 of 13 patients in the pravastatin group and in 11 of 14 controls (P = NS). Nucleation time was comparable between the 2 groups (13 +/- 3 vs. 9 +/- 3 days, P = NS). Bile salt species and molecular species of phospholipids determined with high-performance liquid chromatography did not differ either between both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholesterol gallstone formation in man and potential treatments of the gallbladder motility defect

Cholelithiasis affects 10-15% of the adult population in Western society, and about 75% of gallstones are of cholesterol type. Hepatic hypersecretion of cholesterol with the formation of instable cholesterol-rich vesicles in bile, an imbalance between nucleation-inhibiting and nucleation-promoting proteins with further aggregation of cholesterol crystals in a gallbladder with a motility defect (stasis), all play a role in the pathogenesis of cholesterol gallstones. Experimental animal models suggest that gallstone formation can be prevented by improving gallbladder emptying. Thus, a better understanding of the causes underlying the impaired gallbladder motor function in patients with gallstones might lead to the selection of therapeutic approaches for those individuals who are at increased risk for the formation or recurrence of gallstones. The present article focuses on current concepts and theories on the pathogenesis of cholesterol gallstones with emphasis on the gallbladder motility defect. Several treatment strategies for the correction of gallbladder hypomotility are also discussed.