Small-volume gallbladders and decreased motility in patients with achalasia

The Effect of Gastric Electrical Stimulation on Small Bowel Motility in Patients With Gastroparesis and Concomitant Pancreatic and Small Bowel Dysfunction: From Animal Model to Human Application

BACKGROUND/AIMS

Patients with gastroparesis often have biliary/pancreatic and small bowel symptoms but the effects of gastric electrical stimulation on small bowel electrical activity of the mid-gut have not been studied. Animal model aim: Establish gastric and upper small bowel/biliary slow wave activity relationships with electrical stimulation. Human study aim: Demonstrate improvement in symptoms associated with proximal small bowel dysmotility in gastric stimulated patients.

MATERIALS AND METHODS

Animal model: In vivo evoked responses of duodenal and Sphincter of Oddi measures recorded during gastric electrical stimulation in a nonsurvival swine model (N = 3). High-resolution electrical slow wave mapping of frequency, amplitude, and their ratio, for duodenal and Sphincter of Oddi electrical activity were recorded. Human study: Patients (N = 8) underwent temporary gastric stimulation with small bowel electrodes. Subjective and objective data was collected before and after temporary gastric stimulation. Symptom scores, gastric emptying times, and mucosal electrograms via low-resolution mapping were recorded.

RESULTS

Animal gastric stimulation resulted in some changes in electrical activity parameters, especially with the highest energies delivered but the changes were not statistically significant. Human study revealed improvement in symptom and illness severity scores, and changes in small bowel mucosal slow wave activity.

CONCLUSIONS

Gastric electrical stimulation in an animal model seems to show nonsignificant effects small bowel slow wave activity and myoelectric signaling, suggesting the existence of intrinsic neural connections. Human data shows more significance, with possible potential for therapeutic use of electrical stimulation in patients with gastroparesis and pancreato-biliary and small bowel symptoms of the mid-gut. This study was limited by the nonsurvival pig model, small sample size, and open label human study.

Cholecystectomy for biliary dyskinesia: how did we get there?

BACKGROUND

The focus of biliary dyskinesia (BD) shifted within the last 30 years, moving from symptoms after cholecystectomy (CCY) to symptoms with morphological normal gallbladder, but low gallbladder ejection fraction.

METHODS

We searched the pubmed database to systematically review studies focusing on the diagnosis and treatment of gallbladder dysfunction.

RESULTS

Impaired gallbladder contraction can be found in about 20% of healthy controls and an even higher number of patients with various other disorders. Surgery for BD increased after introduction of laparoscopic CCY, with BD now accounting for >20% of CCY in adults and up to 60% in pediatric patients. The majority of cases reported were operated in the USA, which differs from surgical series for cholelithiasis. Postoperative outcomes do not differ between groups with abnormal or normal gallbladder function.

CONCLUSION

Functional gallbladder testing should not be seen as an indicator of relevant biliary tract disease or prognostic marker to identify patients who may benefit from operative intervention. Instead biliary dyskinesia should be considered as a part of a spectrum of functional disorders, which are generally managed conservatively. Small proof of concept studies have demonstrated effects of medical therapy on biliary dysfunction and should thus be never tested in appropriately designed trials.

Effect of endogenous hypergastrinemia on gallbladder volume and ejection fraction in patients with autoimmune gastritis

BACKGROUND

Gastrin has a cholecystokinetic action on gallbladder motility, and cholecystokinin and gastrin act directly on the smooth muscle of the gallbladder. The aim of this study was to investigate the effect of endogenous hypergastrinemia on gallbladder motility in patients with autoimmune gastritis.

METHODS

Forty-one patients (29 females, 12 males; mean age, 46 years) with autoimmune gastritis and 29 healthy subjects (17 females, 12 males; mean age, 44.8 years) were enrolled in the study. Fasting and postprandial gallbladder volumes were measured ultrasonographically with the ellipsoid technique and the ejection fraction of the gallbladder was calculated from fasting and postprandial volumes. All subjects were investigated after 12 hours of fasting and 30 minutes after a standard test meal.

RESULTS

The gallbladder ejection fraction (%) of the patients with autoimmune gastritis was lower than that of the control group (46.06+/-18.28% vs 55.03+/-14.67%, P=0.032). There was no difference between patients with autoimmune gastritis and the control group in terms of the mean fasting gallbladder volume (30.38+/-12.85 vs 29.27+/-9.91 cm3, P=0.189) and the mean postprandial gallbladder volume (15.67+/-8.32 vs 13.44+/-7.69 cm3, P=0.258). Logistic regression analysis of baseline parameters revealed that "abdominal bloating" was a risk factor for the low gallbladder ejection fraction in autoimmune gastritis patients (P=0.045, F=4.40). In addition, logistic regression analysis of baseline parameters revealed that smoking (n=5, P=0.025, F=5.44) is a predictor of low gallbladder ejection fraction in patients with autoimmune gastritis.

CONCLUSIONS

Patients with endogenous hypergastrinemia have a low gallbladder ejection fraction compared with healthy controls. This study shows that at least part of upper gastrointestinal symptoms observed in this patient population may be due to altered gallbladder motility.

Neural autoantibody profile of primary achalasia

The etiology and pathogenesis of primary achalasia are both unknown. Postulated mechanisms include autoimmune, viral-immune, and central neurodegenerative. The aim of this study is to investigate the serum profile of neural autoantibodies in patients with primary achalasia. Coded sera from 70 patients with primary achalasia and 161 healthy control subjects, matched in sex, age, and smoking habits, were screened for antibodies targeting neuronal, glial, and muscle autoantigens. No specific myenteric neuronal antibody was identified. However, the overall prevalence of neural autoantibodies in patients with primary achalasia was significantly higher than in healthy control subjects (25.7 vs. 4.4%, P < 0.0001). Most noteworthy was the 21.4% frequency of glutamic acid decarboxylase-65 antibody in patients with achalasia (versus 2.5% in control subjects), in the absence of diabetes or companion antibodies predictive of type 1 diabetes. This profile of autoantibodies suggests an autoimmune basis for a subset of primary achalasia.