Purpose: Sphincter of Oddi manometry (SOM) is used to detect biliary sphincter (BSH) and pancreatic sphincter (PSH) hypertension. Manometric asymmetry of these sphincters has not been assessed. Aim: To evaluate for the presence of sphincteric asymmetry using SOM. Methods: SOM performed over a 2 month period from 39 consecutive patients (M:F 8:31, mean age 46 yr. range 16-80 yr.) were analyzed. SOM was performed using a 3-port catheter (Wilson-Cook, Winston-Salem, NC); the proximal (PRX) and distal (DIST) ports are 2 mm apart and orientated at 90° to each other. The middle port is used for aspiration. A resting pressure of ≥ 40mmHg was considered elevated. To evaluate if pressure varies with a 90° rotation at a station on the longitudinal axis of the sphincter, PRX and DIST basal pressures were compared when each were positioned at the same station within the sphincter. Stations were only included for analysis if good quality steady state recordings were made in both ports. Results: A total of 288 manometry stations were analyzed from 27 biliary and 33 pancreatic manometries. Of the normotensive sphincters, at least one lead was abnormal in 7/9(78%) of the biliary and 4/7(57%) of the pancreatic studies. The frequency of pressure differences (dP) between PRX and DIST in BSH, PSH, normal biliary (NBS) and pancreatic sphincters (NPS), and PSH after biliary sphincterotomy alone (PSHpBS) is summarized below: Pressure Difference (dP), mm Hg 0 1-20 21-40 41-60 61-80 >80 BSH (n=72) 15% 32% 30% 12% 3% 8% PSH (n=106) 5% 44% 21% 13%, 6% 11% NBS (n=51) 21% 59% 18% 2% 0 0 NPS (n=28) 14% 61% 25% 0 0 0 PSHpBS (n=31) 13% 68% 19% 0 0 0 The PRX and DIST ports had the same pressure measurement in only 35 (12%) stations; in 47% of BSH and 43% of PSH stations one port was hypertensive and the other normal. In 23% and 30% of stations in BSH and PSH respectively, dP in the two ports was greater than 40 mm Hg. Conclusion: 1) There is manometric asymmetry of the sphincter of Oddi; a 90° change in orientation of the pressure sensor at a given station can result in differences in pressure measurement. This is more pronounced in hypertensive sphincters. 2) In PSH, asymmetry is reduced after biliary sphincterotomy. 3) Further study is needed to determine the clinical significance of asymmetry and whether pressure measurement in several orientations will improve the sensitivity and specificity of SOM.
|Original language||English (US)|
|State||Published - Dec 1 1998|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging