- Email: [email protected]
Manometric evaluation of the papilla of Vater
126
Manometric evaluation of the papilla of Vater Otto T. Nebel, LCDR MC, USNR San Diego, California
Manometric recordings were obtained using a single lumen perfused catheter that was inserted by duodenoscopy into the orifice of the papilla of Vater. Using duodenal pressure as a zero reference, a high pressure zone located just within the papilla of Vater was recorded in all subjects. Intravenous diazepam produced no significant change in sphincter pressure. Sphincter pressures measured in 20 subjects with no recognizable pancreatic or biliary disease ranged from 15 mm to 43 mm Hg with a mean pressure of 31 ± 2 mm Hg (± SE). These data indicate that there is a physiologic high pressure zone in the region of the papilla of Vater. The importance of this sphincter in health and disease remains to be evaluated.
T
he accurate measurement of sphincteric pressure was made possible by the introduction of the infused system of manometry.' This advance resulted in the physiologic study of a variety of gastrointestinal sphincters, including the lower esophageal, pyloric, ileocecal, and anal sphincters. However, the sphincter of Oddi, protected by its anatomic position, has resisted direct evaluation. The development of duodenoscopes designed specifically for cannulation of the papilla of Vater, and the production of a perfused manometric catheter that could be used through these endoscopes has allowed direct manometric study of the papillary region. The purpose of this report is to describe a new technic for sphincter of Oddi manometry.
Manometric technic: The manometric catheter was constructed ofTeflon 1.5 mm in diameter and 200cm long (Figure 1). The end of the tube was sealed and a side hole 0.8 mm in diameter was drilled just behind the sealed portion. A standard intravenous fitting was attached to the proximal end. During sphincter pressure measurements, the manometric catheter
METHODS Duodenoscopy and Cannulation: The duodenoscope OF-B) manufactured by the Olympus Corporation was used in this study. Premedication consisted of pharyngeal anesthesia with Cetacaine spray and, later, sedation with diazepam (10 mg to 20 mg I V). Duodenoscopy and cannulation of the papilla of Vater was performed using the technique previously reported.' In most patients, the entire procedure was completed in the left lateral decubitus position.
Figure 1. Manometric catheter 1.5 mm in diameter and 200 cm in length (inset, catheter tip showing sealed tip and side-hole orifice).
From the Gastroenterology Branch, Department of Internal Medicine, and the Clinical Investigation Center, Naval Regional Medical Center, San Diego, California. Reprint requests: LCDR Otto T. Nebel, Naval Regional Medical Center, San Diego, California 92134. The opinions expressed herein are those of the author and cannot be construed as reflecting the views of the Navy Department or the naval service at large. GASTROINTESTINAL ENDOSCOPY
127
RESULTS The length and small intraluminal diameter of the recording catheter create a unique sensitivity to change in infusion rate. As the rate of infusion increases, a constant increase in pressure was recorded (Figure 2). At an infusion speed of 0.2 ml per minute, a pressure of 3 mm mercury was produced due to internal resistance. This pressure generated by the infusion of the water through the catheter remained constant, as long as the rate of infusion remained constant. Although an area of high pressure can be recorded by simply inserting a catheter into the sphincter, the preferred technic is to insert the catheter beyond the sphincter and into the pancreatic duct or biliary tree. The catheter is then slowly pulled through the sphincter, into the duodenum under direct vision. Using a "pull-through" technic, an area of increased pressure was recorded in the ampullary region of the papilla of Vater in all patients studied to date (Figure 3). The area of high pressure was only a few millimeters in length and the increased pressure was recorded as soon as the catheter had entered the papillary orifice. Since most subjects prefer sedation previous to endoscopic procedures, the effect of various agents on sphincter pressure was one of our first areas of concern. In 5 volunteer subjects, continuous recording of sphincter pressure 5 minutes before and 16 minutes after sedation with diazepam (15 mg IV) revealed no significant change (P > .05) in sphincter pressure (Figure 4). As a result of these data, further studies were per-
"
P
"
II
•. ,
INFUSION
1
CCI
SPEED
min.
Figure 2. Pressure (AP) response to change in infusion rate (AF).
was perfused with distilled water using an infusion pump (Harvard model 933) at a rate of 0.2 ml per minute. Intraluminal pressure was transmitted through the water-filled catheter to an external transducer (Hewlett-Packard series 1280) and recorded on a multichannel direct-writing recorder (Hewlett-Packard model 7788-A) in millimeters of mercury. Sphincter pressure for each minute of the procedure was calculated using duodenal pressure as the zero reference.
!
~.
L 5' .
;.. ~: 10. .
..
7'! ~ : •.
t.1' ..
..
F;gu", 3. M,oomw'c
""'0'
showing duodenal pressure (B), sphincter pressure (SOP), and duct pressure (DP).
MlNUTII
Test Subjects: Preliminary studies were performed in 5 male volunteers (mean age 38, range 18-45), after obtaining their informed consent. Subsequent studies were obtained in 20 patients who were being evaluated for abdominal pain and who, at the completion of their evaluation, had no evidence of organic disease. "Student's" T-test was used for statistical analysis of these data.
formed with both pharyngeal anesthesia (cetacaine spray) and sedation (diazepam 10-20 mg IV). Sphincter of Oddi pressure measured in 20 subjects with no recognizable pancreatic or biliary disease was 31 ± 2 mm Hg with a range of 18 mm to 45 mm Hg(Figure 5). The procedure was well-tolerated by all subjects and added only 15 minutes to the time usually required for duodenoscopy. To date, we
SOP 31
6 P z
SOP ....-....-:::q~~"",e:.~===*:::::~~TlI":::l~~-
-4
..
II
-, MINUTES
Figure 4. Sphincter of Oddi pressure (SOP) response to diazepam (15 mg IV). Vertical lines indicate:!: 1 Sf of the mean. Volume 21, No.3. 1975
f. • ~ •• •• • •
.....---------------
Figure 5. Sphincter of Oddi pressure (SOP) in 20 normal subjects. The small horizontal line indicates the mean SOP for the group.
128
have had no complications following papilla of Vater manometry. DISCUSSION The demonstration that the constant infusion of a small amountof fluid through the recording catheter resulted in an accurate quantitation of sphincter pressure, revolutionized the study of gastrointestinal sphincters.' Except for miniature transducers, the infused manometric technic has completely replaced all other technics for sphincter manometry. The principles for recording sphincter of Oddi pressure are the same as those for evaluating other gastrointestinal sphincters. 3 The side-hole recording orifice is occluded as the catheter is pulled into the sphincter. The constant infusion of water then increases intracatheter pressure until the pressure within the catheter ee,uals the force of occlusion. At this point, the fluid escapes through the orifice, and the force with which the sphincter squeezes the catheter is recorded. Although the technic of recording sphincter of Oddi pressure is analogous to that used in recording the pressure of other gastrointestinal sphincters, the small manometric catheter does present some unique problems. It has previously been shown that sphincter pressure is independent of the rate of infusion. 3fi • However, when small-diameter catheters are used, an increase in baseline pressure due to the inability of the infused fluid to flow unimpeded through the catheter may be produced. This pressure is a function of the fluid viscosity, the internal resistance of the system, and the rate of infusion. Since the fluid viscosity and internal resistance of the catheter remain constant, baseline resting pressure becomes directly proportional to the infusion rate. Although it is possible to eliminate the pressure artifacts caused by rapid infusion through small-diameter catheters by using slow infusion rates, the rate of infusion is the primary determinant of the rate of increase in recorded pressure. Therefore, when slow infusion rates are used, the peak pressure may be delayed or truncated.5fi 6 Since the elevation of baseline pressure due to internal resistance is constant as long as the infusion rate is constant, the ideal infusion rate is one that causes minimal increase in baseline pressure, yet provides a rapid state of equilibrium once the catheter orifice is occluded by the sphincter. Another problem peculiar to this system is the problem of catheter obstruction. Although the catheter may be flexed nearly 90° without affecting the flow, there is little allowable lateral movement. The side walls of the endoscope channel are parallel to the manometric catheter and a small lateral movement may cause kinking with a sudden rise in pressure. The rate of this increased pressure is directly proportional to the infusion rate. This artifact is easily recognized and may be prevented by keeping the cannula under constant endoscopic observation.
Anatomic studies indicate that the biliary tract sphincter begins as the common bile duct enters the duodenal wall. 7 The sphincter fibers continue distally where they are most highly developed, just proximal to its junction with the main pancreatic duct. The lower end of the main pancreatic duct may also be surrounded by angular muscle fibers, but this is less constant. Finally, when an ampulla of Vater is present, it too may be surrounded by a third sphincter. This sphincter, like that of the main pancreatic duct, is less constant and less well developed than the sphincter of Oddi at the distal end of the common bile duct.· On the basis of anatomic studies, several high-pressure zones may be expected in the papillary area. Recent work using an infused manometric catheter to study the opposum papillary area have demonstrated the presence of 3 distinct high-pressure zones: an ampullary sphincter, biliary duct sphincter, and pancreatic duct sphincter.- In man, the presence of 3 functional sphincters has not been consistently demonstrated. By inserting the manometry catheter through the orifice and into the pancreatic or biliary system, we have been able to demonstrate only 1 area of high pressure. Whether there is, in fact, only 1 physiologic sphincter or, whether the orifice of the recording catheter is too large to manometrically separate several small sphincteric areas, remains to be evaluated. Although we have used the term "sphincter of Oddi" to indicate the papillary high-pressure zone, the exact anatomic-manometric relationship has not been defined. Further studies utilizing simultaneous radiographic and manometric evaluation of both the biliary and pancreatic systems will be required in order to identify the importance of each anatomic region in producing the high-pressure zone. The effect of various substances on sphincter pressure is just in the preliminary stages of testing, but the lack of sphincter response to diazepam allows the procedure to be performed more conveniently and with greater precision. In addition to decreased patient discomfort, the sedation promotes regular, shallow respiration. This decreases respiratory-induced duodenal movement which allows more uniform placement and retention of the manometry catheter in the area of maximum sphincter pressure. Although we have experienced no complications from papilla of Vater manometry, its safety as a procedure remains unknown. While it should be comparable to that of endoscopic ductography, the nature of the injected fluid (water) and small volumes involved (0.2 ml per minute) may reduce the complication rate to that of duodenoscopy. These studies indicate that there is an area of high pressure in the region of the papilla of Vater that can be measured by endoscopic manometric technics. The physiologic control of this sphincter and its importance remain to be evaluated.
REFERENCES 1. WYNANS CS, HARRIS LD: Quantitation of lower esophageal sphincter competence. Gastroenterology 52 :773, 1967 2. NEBEl OT, FORNES MF: Endoscopic pancreatocholangiography. AmerJ Dig Dis 18:1042, 1973 3. BIANCANI P, GOYAL RK, PHILLIPS A, SPIRO HM: Mechanics of sphincter action. } Clin Invest 52 :2973, 1973 4. RINALDO JA, LEVEY JF: Correlation of several methods for recording esophageal sphincter pressures. Am J Dig Dis 13:882, 1968 5. POPE CE: Effect of infusion on force of closure measurements in human esophagus. Gastroenterology 58:616, 1970
6. HOlLIS IB, CASTELL DO: Ampitude of esophageal peristalsis as determined by rapid infusion. Gastroenterology 63:417,1972 7. BOYDEN EA: The sphincter of Oddi in man and certain representative mammals. Surgery 1:25, 1937 8. 0001 R: D'une disposition a sphincter speciale de I'ouverture du canal choledoque. Arch Ital Bioi 8:317, 1887 9. SHELHAMER J: Physiology of bile transport: xanometric studies of common bile duct and sphincter of Oddi. Gastroenterology 63:247, 1973
GASTROINTESTINAL ENDOSCOPY
Manometric evaluation of the papilla of Vater Otto T. Nebel, LCDR MC, USNR San Diego, California
Manometric recordings were obtained using a single lumen perfused catheter that was inserted by duodenoscopy into the orifice of the papilla of Vater. Using duodenal pressure as a zero reference, a high pressure zone located just within the papilla of Vater was recorded in all subjects. Intravenous diazepam produced no significant change in sphincter pressure. Sphincter pressures measured in 20 subjects with no recognizable pancreatic or biliary disease ranged from 15 mm to 43 mm Hg with a mean pressure of 31 ± 2 mm Hg (± SE). These data indicate that there is a physiologic high pressure zone in the region of the papilla of Vater. The importance of this sphincter in health and disease remains to be evaluated.
T
he accurate measurement of sphincteric pressure was made possible by the introduction of the infused system of manometry.' This advance resulted in the physiologic study of a variety of gastrointestinal sphincters, including the lower esophageal, pyloric, ileocecal, and anal sphincters. However, the sphincter of Oddi, protected by its anatomic position, has resisted direct evaluation. The development of duodenoscopes designed specifically for cannulation of the papilla of Vater, and the production of a perfused manometric catheter that could be used through these endoscopes has allowed direct manometric study of the papillary region. The purpose of this report is to describe a new technic for sphincter of Oddi manometry.
Manometric technic: The manometric catheter was constructed ofTeflon 1.5 mm in diameter and 200cm long (Figure 1). The end of the tube was sealed and a side hole 0.8 mm in diameter was drilled just behind the sealed portion. A standard intravenous fitting was attached to the proximal end. During sphincter pressure measurements, the manometric catheter
METHODS Duodenoscopy and Cannulation: The duodenoscope OF-B) manufactured by the Olympus Corporation was used in this study. Premedication consisted of pharyngeal anesthesia with Cetacaine spray and, later, sedation with diazepam (10 mg to 20 mg I V). Duodenoscopy and cannulation of the papilla of Vater was performed using the technique previously reported.' In most patients, the entire procedure was completed in the left lateral decubitus position.
Figure 1. Manometric catheter 1.5 mm in diameter and 200 cm in length (inset, catheter tip showing sealed tip and side-hole orifice).
From the Gastroenterology Branch, Department of Internal Medicine, and the Clinical Investigation Center, Naval Regional Medical Center, San Diego, California. Reprint requests: LCDR Otto T. Nebel, Naval Regional Medical Center, San Diego, California 92134. The opinions expressed herein are those of the author and cannot be construed as reflecting the views of the Navy Department or the naval service at large. GASTROINTESTINAL ENDOSCOPY
127
RESULTS The length and small intraluminal diameter of the recording catheter create a unique sensitivity to change in infusion rate. As the rate of infusion increases, a constant increase in pressure was recorded (Figure 2). At an infusion speed of 0.2 ml per minute, a pressure of 3 mm mercury was produced due to internal resistance. This pressure generated by the infusion of the water through the catheter remained constant, as long as the rate of infusion remained constant. Although an area of high pressure can be recorded by simply inserting a catheter into the sphincter, the preferred technic is to insert the catheter beyond the sphincter and into the pancreatic duct or biliary tree. The catheter is then slowly pulled through the sphincter, into the duodenum under direct vision. Using a "pull-through" technic, an area of increased pressure was recorded in the ampullary region of the papilla of Vater in all patients studied to date (Figure 3). The area of high pressure was only a few millimeters in length and the increased pressure was recorded as soon as the catheter had entered the papillary orifice. Since most subjects prefer sedation previous to endoscopic procedures, the effect of various agents on sphincter pressure was one of our first areas of concern. In 5 volunteer subjects, continuous recording of sphincter pressure 5 minutes before and 16 minutes after sedation with diazepam (15 mg IV) revealed no significant change (P > .05) in sphincter pressure (Figure 4). As a result of these data, further studies were per-
"
P
"
II
•. ,
INFUSION
1
CCI
SPEED
min.
Figure 2. Pressure (AP) response to change in infusion rate (AF).
was perfused with distilled water using an infusion pump (Harvard model 933) at a rate of 0.2 ml per minute. Intraluminal pressure was transmitted through the water-filled catheter to an external transducer (Hewlett-Packard series 1280) and recorded on a multichannel direct-writing recorder (Hewlett-Packard model 7788-A) in millimeters of mercury. Sphincter pressure for each minute of the procedure was calculated using duodenal pressure as the zero reference.
!
~.
L 5' .
;.. ~: 10. .
..
7'! ~ : •.
t.1' ..
..
F;gu", 3. M,oomw'c
""'0'
showing duodenal pressure (B), sphincter pressure (SOP), and duct pressure (DP).
MlNUTII
Test Subjects: Preliminary studies were performed in 5 male volunteers (mean age 38, range 18-45), after obtaining their informed consent. Subsequent studies were obtained in 20 patients who were being evaluated for abdominal pain and who, at the completion of their evaluation, had no evidence of organic disease. "Student's" T-test was used for statistical analysis of these data.
formed with both pharyngeal anesthesia (cetacaine spray) and sedation (diazepam 10-20 mg IV). Sphincter of Oddi pressure measured in 20 subjects with no recognizable pancreatic or biliary disease was 31 ± 2 mm Hg with a range of 18 mm to 45 mm Hg(Figure 5). The procedure was well-tolerated by all subjects and added only 15 minutes to the time usually required for duodenoscopy. To date, we
SOP 31
6 P z
SOP ....-....-:::q~~"",e:.~===*:::::~~TlI":::l~~-
-4
..
II
-, MINUTES
Figure 4. Sphincter of Oddi pressure (SOP) response to diazepam (15 mg IV). Vertical lines indicate:!: 1 Sf of the mean. Volume 21, No.3. 1975
f. • ~ •• •• • •
.....---------------
Figure 5. Sphincter of Oddi pressure (SOP) in 20 normal subjects. The small horizontal line indicates the mean SOP for the group.
128
have had no complications following papilla of Vater manometry. DISCUSSION The demonstration that the constant infusion of a small amountof fluid through the recording catheter resulted in an accurate quantitation of sphincter pressure, revolutionized the study of gastrointestinal sphincters.' Except for miniature transducers, the infused manometric technic has completely replaced all other technics for sphincter manometry. The principles for recording sphincter of Oddi pressure are the same as those for evaluating other gastrointestinal sphincters. 3 The side-hole recording orifice is occluded as the catheter is pulled into the sphincter. The constant infusion of water then increases intracatheter pressure until the pressure within the catheter ee,uals the force of occlusion. At this point, the fluid escapes through the orifice, and the force with which the sphincter squeezes the catheter is recorded. Although the technic of recording sphincter of Oddi pressure is analogous to that used in recording the pressure of other gastrointestinal sphincters, the small manometric catheter does present some unique problems. It has previously been shown that sphincter pressure is independent of the rate of infusion. 3fi • However, when small-diameter catheters are used, an increase in baseline pressure due to the inability of the infused fluid to flow unimpeded through the catheter may be produced. This pressure is a function of the fluid viscosity, the internal resistance of the system, and the rate of infusion. Since the fluid viscosity and internal resistance of the catheter remain constant, baseline resting pressure becomes directly proportional to the infusion rate. Although it is possible to eliminate the pressure artifacts caused by rapid infusion through small-diameter catheters by using slow infusion rates, the rate of infusion is the primary determinant of the rate of increase in recorded pressure. Therefore, when slow infusion rates are used, the peak pressure may be delayed or truncated.5fi 6 Since the elevation of baseline pressure due to internal resistance is constant as long as the infusion rate is constant, the ideal infusion rate is one that causes minimal increase in baseline pressure, yet provides a rapid state of equilibrium once the catheter orifice is occluded by the sphincter. Another problem peculiar to this system is the problem of catheter obstruction. Although the catheter may be flexed nearly 90° without affecting the flow, there is little allowable lateral movement. The side walls of the endoscope channel are parallel to the manometric catheter and a small lateral movement may cause kinking with a sudden rise in pressure. The rate of this increased pressure is directly proportional to the infusion rate. This artifact is easily recognized and may be prevented by keeping the cannula under constant endoscopic observation.
Anatomic studies indicate that the biliary tract sphincter begins as the common bile duct enters the duodenal wall. 7 The sphincter fibers continue distally where they are most highly developed, just proximal to its junction with the main pancreatic duct. The lower end of the main pancreatic duct may also be surrounded by angular muscle fibers, but this is less constant. Finally, when an ampulla of Vater is present, it too may be surrounded by a third sphincter. This sphincter, like that of the main pancreatic duct, is less constant and less well developed than the sphincter of Oddi at the distal end of the common bile duct.· On the basis of anatomic studies, several high-pressure zones may be expected in the papillary area. Recent work using an infused manometric catheter to study the opposum papillary area have demonstrated the presence of 3 distinct high-pressure zones: an ampullary sphincter, biliary duct sphincter, and pancreatic duct sphincter.- In man, the presence of 3 functional sphincters has not been consistently demonstrated. By inserting the manometry catheter through the orifice and into the pancreatic or biliary system, we have been able to demonstrate only 1 area of high pressure. Whether there is, in fact, only 1 physiologic sphincter or, whether the orifice of the recording catheter is too large to manometrically separate several small sphincteric areas, remains to be evaluated. Although we have used the term "sphincter of Oddi" to indicate the papillary high-pressure zone, the exact anatomic-manometric relationship has not been defined. Further studies utilizing simultaneous radiographic and manometric evaluation of both the biliary and pancreatic systems will be required in order to identify the importance of each anatomic region in producing the high-pressure zone. The effect of various substances on sphincter pressure is just in the preliminary stages of testing, but the lack of sphincter response to diazepam allows the procedure to be performed more conveniently and with greater precision. In addition to decreased patient discomfort, the sedation promotes regular, shallow respiration. This decreases respiratory-induced duodenal movement which allows more uniform placement and retention of the manometry catheter in the area of maximum sphincter pressure. Although we have experienced no complications from papilla of Vater manometry, its safety as a procedure remains unknown. While it should be comparable to that of endoscopic ductography, the nature of the injected fluid (water) and small volumes involved (0.2 ml per minute) may reduce the complication rate to that of duodenoscopy. These studies indicate that there is an area of high pressure in the region of the papilla of Vater that can be measured by endoscopic manometric technics. The physiologic control of this sphincter and its importance remain to be evaluated.
REFERENCES 1. WYNANS CS, HARRIS LD: Quantitation of lower esophageal sphincter competence. Gastroenterology 52 :773, 1967 2. NEBEl OT, FORNES MF: Endoscopic pancreatocholangiography. AmerJ Dig Dis 18:1042, 1973 3. BIANCANI P, GOYAL RK, PHILLIPS A, SPIRO HM: Mechanics of sphincter action. } Clin Invest 52 :2973, 1973 4. RINALDO JA, LEVEY JF: Correlation of several methods for recording esophageal sphincter pressures. Am J Dig Dis 13:882, 1968 5. POPE CE: Effect of infusion on force of closure measurements in human esophagus. Gastroenterology 58:616, 1970
6. HOlLIS IB, CASTELL DO: Ampitude of esophageal peristalsis as determined by rapid infusion. Gastroenterology 63:417,1972 7. BOYDEN EA: The sphincter of Oddi in man and certain representative mammals. Surgery 1:25, 1937 8. 0001 R: D'une disposition a sphincter speciale de I'ouverture du canal choledoque. Arch Ital Bioi 8:317, 1887 9. SHELHAMER J: Physiology of bile transport: xanometric studies of common bile duct and sphincter of Oddi. Gastroenterology 63:247, 1973
GASTROINTESTINAL ENDOSCOPY