Effect of gastric distension on sphincter of Oddi motility in humans

A552 AGA ABSTRACTS G2257

EFFECT OF GASTRIC DISTENSION ON SPHINCTER OF ODDI MOTILITY IN HUMANS. B.M. Yon. J.H. Kim, J.M. Kim, Y.J. Shin, K.B. Hahm, S.W. Cho. Department of Gastroenterology, Ajou University School of Medicine, Suwon, Korea

Background~Aim: Although there are many reports in the literature of clinical syndromes resulting from sphincter of Oddi (SO) dysfunction, little is known about the effects of normal physiologic stimuli on SO function. The present study was designed to evaluate the effect of gastric distension on the SO motility through percutaneous transhepatic manometry. Methods: The motility of SO and small bowel(SB) were measured simultaneously by percutaneous transhepatic manometry using 8-lumen perfusion catheter (Zinetic Medical, 3 orifices for SO manometry: 2mm apart and 5 orifices for SB manometry: 10mm apart) in 6 patients(M:F=3:3, mean age: 67.5 years) with intrahepatic stones after complete stone removal by cholangioscopic lithotripsy. They had no previous hepatobiliary or gastrointestinal operation, papillary stenosis, and periampullary diverticulum. After positioning the catheter via PTBD tract, basal recording was performed. Gastric balloon was performed by ballooned nasogastric tube. The balloon was inflated on the regular contraction phase of SO until the patients felt epigastric discomfort. Result: The mean inflation volume of gastric balloon was 450ml (range: 300-700ml). At baseline manometric study, the basal pressure and amplitude and frequency of phasic contraction wave were 20.8 ± 2.3mmHg, 93.4 + 39.1mmHg, and 3.5 ± 1.3/min, respectively. After inflating the gastric balloon, the frequency of phasic contraction decreased to 0.8 + 1.2/min(p<0.05). But basal SO pressure and amplitude of phasic contraction wave were not changed at 3.5±2.2 mmHg(p>0.05) and 36.6 ± 50.8mmHg(p>0.05), respectively. Conclusion: Gastric distension does not affect SO basal pressure and amplitude of phasic contraction wave, but decreases the contraction frequency of SO in humans. • G2258

EFFECT OF SECRETIN ON SPHINCTER OF ODDI MOTILITY IN HUMANS. B.M. Yon, J.H. Kim, J.M Kim, Y.J. Shin, K.B. Hahm, S.W. Cho. Department of Gastroenterology, Ainu University School of Medicine, Suwon, Korea

Background & Aim: There are several pharmacological active agents that are able to affect the sphincter of Oddi(SO) motility, such as somatostatin, morphine, and motilin. The effect of secretin on human SO is not well known. The present study was designed to evaluate the effect of secretin on the SO motility through percutaneous traushepatic manometry. Methods: The motility and SO and small bowel(SB) were measured simultaneously by percutaneous transhepatic manometry using 8-lumen perfusion catheter (Zinetic Medical, 3 orifices for SO manometry: 2mm apart and 5 orifices for SB manometry: 10mm apart) in 6 patients(M:F=2:4, mean age: 67.8 years) with intrahepatic stones after complete stone removal by cholangioscopic lithotripsy. After positioning the catheter via PTBD tract, basal recording was performed. Secretin(50 secretin unit) was injected intravenously at regular contraction phase of SO. Results: The secretin induced high frequency contractions within 2.5± 1.94 min. The duration of high frequency contractions was 6.4 ± 2.7 min. The basal pressure and amplitude and frequency of phasic contractions and motility index were 17.9 ± 2.6 mmHg, 43.6 ± 13.4mmHg, 4.6 ± 1.2/min, and 6.6 ± 0.4 mmHgsec/min, respectively. After intravenous administration of the secretin, the basal pressure was 7.7 ± 4.9mmHg (p>0.05). The amplitude of phasic contractions was increased to 59.2 ± 16.3 mmHg. The frequency of phasic contraction increased to ll.l±0.6/min(p<0.05). The motility index was increased to 7.7± 0.3 mmHgsec/min. After high frequency contractions, quiescent period was seen with the mean duration of 3.4 ± 1.5 rain. Conclusion: These results suggest that secretin has a biphasic effect to SO motility in humans with the high frequency contractions followed by quiescent period. • G2259 CHOLESTAN-3[~,5cx,6[3-TRIOL SUPPRESSES BILE ACID-INDUCED MUCIN SECRETION BY DOG GALLBLADDER EPITHELIAL CELLS. T: Yoshida. J. H. Klinkspoor, S. P. Lee. Dept. of Medicine, Univ. of Washington and Seattle VAMC, Seattle, WA. BACKGROUND/AIM: Oxysterols have been identified from tissue specimens, and they have multiple biological activities, as well as toxic effects. The biliary tract is exposed to high concentrations of lipids and possibly oxysterols. However, effects of oxysterols on biliary epithelial cells have not been reported. In this study, we have investigated the effects of oxysterols on cell viability and mucin secretion, using dog gallbladder epithelial ceils (DGBE). METHODS: 1. DGBE cells were treated with cholestan-313,5u,613-triol (TriolC) or 7-ketocholesterol (7KC), ranging from 0 to 1001aM, respectively. Growth inhibition by oxysterols was measured by a nonradioactive colorimetric method using tetrazolium salts. 2. DGBE cells, grown to confluence on Transwell inserts, were incubated with model biles containing TriolC or 7KC, ranging from 0 to 12001aM, for 24 hours. Cytotoxic effects of oxysterols were measured by the release of 51Cr from prelabeled cells. Mucin secretion was studied by measuring the secretion of [3H]

GASTROENTEROLOGY Vol. 114, No. 4

N-acetyl-D-glucosamine labeled glycoproteins. RESULTS: 1. The growth of the DGBE cells was inhibited to 39.2±7.5% (P<0.001) and 45.4--. 5.1% (P<0.001) of control by 25~tM of TriolC and 50pM of 7KC, respectively. Both oxysterols inhibited cell growth dose dependently. 2. After the cells were grown to confluence, specific 51Cr releases increased to 21,8+6.2% (P<0.001) of maximum release at 600pM of TriolC and 26.0±4.6% (P<0.001) at 9001aM of 7KC, respectively (control 0.0± 3.0%). The oxysterols both caused a dose-dependent increase in specific 51Cr release. 3. Mucin secretion by the DGBE cells was stimulated by model bile without oxysterol (control). Mucin secretion was suppressed to 77 _+6.9% (P<0.001), 81.5 ± 8.4% (P<0.001), and 84.0 ± 8.4% (P<0.001) of control by model biles containing 1201aM, 2401aM, and 360gM of TriolC, respectively. In contrast, mucin secretion was not affected by model biles containing 7KC. CONCLUSION: 1. The cytotoxic effects of the oxysterols on the DGBE ceils were dependent on the proliferation status of the cells. When the ceils are proliferating, the cytotoxic effects occur at lower concentrations than when the cells are confluent. 2. The different oxysterols have varying effects on the DGBE cells. TriolC was found to be more cytotoxic than 7KC. Mucin secretion was suppressed by TriolC, but not by 7KC. • G2260 EFFECT OF MAGNETIC RESONANCE CHOLANGIOGRAPHY ON PATTERNS OF ERCP USE IN PATIENTS UNDERGOING CHOLECYSTECTOMY. Z Younes. F Regan, R Safdar, B Lacy, T Magnuson. Johns Hopkins Bayview Med Center, Baltimore. Background: Preoperative evaluation of patients scheduled for cholecystectomy with a suspected common bile duct stone (CBDS) often includes endoscopic retrograde cholangio-pancreatography (ERCP). ERCP is invasive, has a complication rate of 5-10%, and is often normal in these patients. Magnetic resonance cholangiography (MRC) is a recent noninvasive radiologic technique which has a high accuracy for CBDS. There are no studies on the clinical role or the utility of MRC in patients undergoing cholecystectomy. This study was performed to show whether the availability of MRC leads to a reduction in the rate of diagnostic(ie normal) ERCPs. Methods: A retrospective analysis of patients who underwent cholecystectomy at an academic medical center from January 1992 to March 1997 was performed. MRC and/or ERCP were performed for clinical suspicion of CBDS. Patients were labeled as having a CBDS if a CBDS confirmed by ERCP or by CBD exploration. Three ERCPs performed for CBD leaks were excluded from the analysis. An "intent to treat" analysis was performed for ERCPs: a failed ERCP was labeled as "therapeutic" if the patient was ultimately found to have a CBDS at surgery or during the postoperative period, or "diagnostic" if the patient had a normal intra-operative cholangiogram and no evidence of a retained CBDS in the postoperative period. Patients were divided into two groups: Group 1 had a cholecystectomy prior to availability of MRC and Group 2 had a cholecystectomy after availability of MRC. Results: Group 1 consisted of 358 patients and Group 2 had 340 patients. Both groups were comparable in age, WBC, total bilirubin, alkaline phosphatase, and AST. 33 patients in Group 1 (9.2%) and 32 patients in Group 2 (9.4%) had CBDS (NS). Group 1 had a total of 57 ERCPs (15.9% of all patients); 28 were diagnostic (7.8% of all patients) and 29 therapeutic. Group 2 had a total of 46 ERCPs (13.5% of all patients); 16 were diagnostic (4.7% of all patients) and 30 therapeutic. Patients in Group 2 had fewer diagnostic ERCPs and had a 39.7% decrease in the rates of diagnostic ERCPs. The percentage of ERCPs being diagnostic was also lower in Group 2. Patients in Group 2 had fewer post-operative ERCPs compared to group 1 (2 versus 9). There was only a slight difference in the total number of ERCPs. A total of 64 patients in Group 2 had an MRC performed. Patients who had MRC had a higher bilirubin and had more CBDS than the rest of the patients. Five surgeons performed 220 (61.45%) of the surgeries in Group 1 and 251 (74.1%) of the surgeries in Group 2. A sub-analysis of these two groups demonstrated a lower rate of diagnostic ERCPs after MRC became available: 15 (6.8%) prior to MRC versus 11 (4.78%) after MRC. Conclusion: Patients who had a cholecystectomy after MRC became available had fewer diagnostic and fewer postoperative ERCPs performed. This difference could not be explained by patient characteristics or by physician factors. Prospective studies are needed to determine whether this translates into improved patient outcomes and lower costs. • G2261 MAGNETIC RESONANCE CHOLANGIOGRAPHY COMPARED TO ULTRASONOGRAPHY IN PATIENTS WITH SUSPECTED BILIARY AND PANCREATIC DISEASES. Z Younes, T Magnuson, F Regan. Divs of Gastroenterology, Surgery, and Radiology, Johns Hopkins Bayview Med Center. Background: Magnetic resonance cholangiography (MRC) is a recently developed imaging technique which allows excellent demonstration of the gall bladder and the biliary system. It has been shown to have a high accuracy in depicting various biliary disorders when compared to the direct cholangiographic techniques. Ultrasonography (US) is the initial diagnostic procedure for most patients with suspected biliary disorders. There are no studies directly comparing MRC and US. Our aim is to show whether MRC is a more useful imaging technique than US, and if so under which