A 4 1 4 A G A A B S T R A C T S G A S T R O E N T E R O L O G Y , Vol . 1 0 8 , No. 4

Q TNERAPEUTIC0 BUT NOT DIAGNOSTIC ERCP CAN INDUCE PANCREATIC PSEUDOTUMOR ON CT. J.H. de Vries', L.E.M. Ouijm ~, W. Dekker I, G.L . GuiL e J. Ferwerda I and E.Th. Scholten e. Departments of IInternal Medicine and ZDiagnostic Radiology, Kennemer Gasthuis, Iokatie EG, Haarlem, The Netherlands. Objective: I t is believed that ERCP frequently induces morphologic changes in the peripapil lary region, which may produce a pancreatic pseudotumor on CT. A prospective study was performed to establish the occurrence of such changes. In addition, complications after ERCP were assessed by CT. Patients and Methods: 58 patients were evaluated. CT was performed a few hours before and the morning after ERCP. A biconvexly enlarged pancreatic head with dimensions out of proportion to the other pancreatic parts was either suspicious for pancreatic tumor or represbnted pseudotumor when seen only on the post-ERCP CT. Patients were not e l ig ib le i f ERCP had been performed in the past. Results: Pre-ERCP CT showed pancreatic tumor or chronic pancreatitis precluding analysis in 19 patients. Of the remaining 39 patients 12 underwent a (precut-) papillotomy (group 1). Pseudotumor of the pancreatic head was demonstrated on CT after ERCP in two patients (173); in the f i r s t patient a standard papillotomy had been performed and in the second a precut-papillotomy. Only one of them showed cl in ical and biochemical signs of pancreatitis. In the 27 patients who underwent diagnostic ERCP (group 2), no changes of the pancreatic head were seen. This difference is s ta t i s t i ca l l y signif icant (Fisher Exact test, p=0.048). Asymptomatic retroperitoneal duodenal perforation after

i recut-papillotomy was demonstrated on CT in three patients 253). Pancreatitis was demonstrated on one post-ERCP CT. A

precut- papillotomy had been performed in this patient, who also developed cl in ical and biochemical signs of pancreatitis. The 60Occ of oral contrast, administered a few hours before endoscopy was never a hindrance to the endoscopist. Conclusions: After ERCP, morphologic changes of the pancreatic head, appearing as pseudotumor on CT occur only when papillotomy has been performed. Therefore, CT remains a valuable diagnostic tool following diagnostic ERCP. Retroperitoneal perforation following papillotomy seems to be a rather frequent complication when sought for routinely.

O C O M P A R A T I V E ACCURACY OF ENDOSCOPIC ULTRASOUND, TRANSABDOMINAL ULTRASOUND AND BILIARY DRAINAGE IN THE DIAGNOSIS OF CHOLECYSTITIS: James E. Dill. Surgical Department/Endoscopy, Community Hospital of Roanoke Valley, Roanoke, VA

B A C K G R O U N D : Transabdominal ultrasound (TUS) has been considered highly accurate in the diagnosis of cholecystitis. In April of 1993 however Dahan, et al., demonstrated that endoscopic ultrasound (EUS) had an 81% accuracy in the diagnosis of cholecystitis in patients with negative TUS. In June of 1994 we reported the use o f combined EUS and stimulated biliary drainage to diagnose cholecystitis. In a recently published preliminary report, we were able to use this method to correctly diagnose cholecystitis preoperatively in 20 out of 21 patients with biliary type pain and negative TUS.

M E T H O D : Further analysis of an extended series of patients (30) was undertaken to compare the preoperative diagnostic accuracy of TUS with various EUS findings, with and without stimulated biliary drainage.

RESULTS: The EUS findings of gallbladder sludge, wall thickening and decreased conlxaction had diagnostic accuracies of 93%, 60% and 53%, respectively. When these findings were each combined with the results o f stimulated biliary drainage the accuracies were 96%, 82% and 74% respectively. TUS had a 10% accuracy in these patients.

C O N C L U S I O N : Combined EUS and stimulated biliary drainage was most accurate in diagnosing cholecystitis. Stimulated biliary drainage did however increase the accuracy of the other findings when combined with them.

• BIOMECHANICAL WALL PROPERTIES OF THE PORCINE COMMON BILE DUCT AND DUCTUS HEPATICUS. B.U. Duch, J.A.K Petersen, H. Gregersen. Institute of Experimental Clinical Research, Section SKS, Aathus University Hospital, Denmark, Institute for Mechanics and Materials, University of California, USA. The distribution of smooth muscles in the bile duct system is very sparse. Contractions cannot be recorded and flow is thought to be regulated by the Sphincter of Oddi. According to classical biomechanical theory the luminal dimension of the duct system and the wall elasticity must be essential to resistance to flow. The propose of this study was to characterize the passive biomechanical wall properties of the normal isolated porcine common bile duct in vitro. A four electrode impedance measuring system located inside a balloon on a probe was constructed (Gastroenterology 1992;103:1547-51, Dig Dis Sci 1993;38:197-205). Simultaneous measures of pressure and bile duct cross sectional area (CSA) were obtained. From these variables it is possible to calculate circumferential wall teosion-strain distributions in order to evaluate the passive wall elasticity. Eleven normal porcine bile ducts were examined. Measurements were done proximal to the ductus cysticus orifice (proximal) and close to the Sphincter of Oddi (distal).The distal CSAs significantly higher than those proximal at all pressure steps (p<0.001). At the lowest applied pressure of 0.5 kPa the CSA was 14.51+1.7 mm 2 and 21.93+-2.7 mm 2 at the proximal and distal measuring point, respectively. The highest applied pressure of 8 kPa resulted in CSAs of 33.74+_3.9 rran 2 proximally and 51.10+ 5.4 mm 2 distally. The circumferential wall teosion-strain distributions fitted well to the expon~rtial equation hi y = a + bx with deterrmnation coefficients of 0.97:L0.01. The value for intercept with the Y-axis (a) is proximal 0.215 _+0.16 and distal -0.162 _+0.23. The slope of the curves (b) was proximal 6.497 i-0.62 and distal 7.334 i-0.91. Neither a or b were statistically different between the two measuring points indicating that the elastic properties did not differ. Assuming that the flow in the bile duct is governed by Poiseuilles law and that all factors except the radius are constants, the computed resistance to flow at a physiological pressure of 0.5 kPa is 2.3 times higher at the proximal location. We conclude that the luminal dimensions differ between ductus hepaticus and the cemmon bile duct whereas no difference in passive tissue dastieity was found.

C o m m o n Bi le D u c t S t o n e s ; W h e t to do a f te r y o u c u t ? RJ.Farrel I .M Goaains.DG.Weir .D .Kel leher .PWN.Keel ino. Dept.of Gastroenterology, St .James's Hospital,Dublin 7,Ireland.

Them am a number of management options to consider after sphincterotomy (ES) is performed for common bile duct stones (CBDS). Regarding CBDS. <1.5cm. is clearance (Balloon or basket) of the CBD. neccessary following an adequate ES? Is endoscopic review neccessary at 1-2 mths. post ES or only in the event of future bilary problems? Does endoscopic stenting provide satisfactoq/management in the event of failed clearance of impacted or large CBDS>1,6 cm. in the eldedy patient (>70yrs.) Msthods:177 pts. who had ES, for CBDS. were retrospectively reviewed between Jan.1992 and Dec.1993, 102 females. Mean age 69.3 yrs. Range 30-95 yrs. Mean follow-up 13.5 mths.58% pts.had a previous cholecystecfomy. ERCPs. were reviewed by a radiologist and clearance and the largest GBDS.size was noted.There was no significant difference between the clearance and non- clearance groups regarding age, sex and cholecystestomy statua.(p=N,S.) Results:336 ERGPs. were performed to clear GBDS. 113 pts.(64°/.) required 1 ERCP+ES., 44 pts. required 2 ERCPs, while 6 pts. required>=3ERCPs. 92 pts; had a clearance attempted post ES.whara both endescopist and radiologist were satisfied the CBDS.had been cleared.63 pts. had no attempted clesrsnc~ i.e. a balloon was inflated in the lower CBD.fo the diameter of the largest stone and an adequate ES.wes adjudged that which allowed passage of the balloon. In 22 pts.clearance was not possible due to impacted or large CBDS. >1.5cm. and initially a stent was inserted.5 required CBD.surgenj, while 17pts. (Mean age 78.3 yrs) were treated conservatively with long term stents with an eventual clear CBD. in 5 pts.(23%).

Summary of Results: ES + Cle/arance(n=92) ES w(o Clesrenc~(n=63) R/v ERCP(63) No R/~I (29) R/V ERCP(51)I No R/v=(12) CBDS.(18)18 % I CBDS.(16)25% I

Unwell(2) Unweil(2) Unwell(O) Unweil(2);RIP(1) Morbidity:O.43% Morbidity:O.47%

Concluslons:Thers was no significant difference in outcome between patients who had attempted duct clearance and those who did not. An adequate ES.is more important than CBDS.cleersnoe. The presence of CBDS.post- ES. does not correlate with morbidity. Review ERCP is recommended in those patients who had no initial clearance. 77% of 10ts. with CBDS.>I.5cm. were successfully managed with stenting,with clearance ultimately achieved in 23%,