Clinical evaluation of sphincter of Oddi manometry

Vincent D. Bradley, MDCamp Pendleton, California

Otto T. Nebel, MDSolana Beach, California

Sphincter of Oddi pressure (SOP) was measured in 50 consecutivepatients referred for evaluation of acute pancreatitis (15 patients),recurrent pancreatitis (21 patients), and postcholecystectomy' syn­drome (14 patients). The mean SOP (±standard error) in the patientswith acute pancreatitis (40±4 mm Hg) and recurrent pancreatitis (50±6mm Hg) was significantly greater (P<Ol), while the SOP in patients withpostcholecystectomy syndrome (38±4 mm Hg) was not significantlydifferent (P>.05) than that of normal control subjects (31±2 mm Hg).The clinical efficacy of this new procedure remains to be determined.

The sphincter of Oddi, originally described as an atomicalentity in 1937,' remained a relatively inaccessible area untilthe advent of duodenoscopy. Duodenoscopy with cannula­tion of the papi Iia of Vater and endoscopic pancreatographyand cholangiography (ERCP) greatly augmented our diagnos­tic ability in a variety of pancreatic and biliary tract diseases. 2

Recently, a method of endoscopic manometry has been de­scribed that further extends our abi lity to eval uate the region ofthe papilla of Vater. 3 This manometric technique allows directmeasurement of sphi ncter ofOddi pressures and thus providesanother means of assessing sphincter function. The purpose ofthis study was to evaluate sphincter of Oddi pressures ingroups of patients who might be expected to have an abnor­mal papilla of Vater.METHODS Included in the study were 50 consecutive pa­tients referred to the gastroenterology cl inic of the San DiegoNaval Hospital for evaluation of acute pancreatitis (15 pa­tients), recurrent pancreatitis (21 patients), and postcholecys­tectomy syndrome (141 patients).

Acute pancreatitis was accepted as the diagnosis in patientswho presented with severe abdominal pain (usually rightupper quadrant) associated with elevated serum amylase ac­tivity. Recurrent pancreatitis was defined, for study purposes,as at least 2 attacks of pancreatitis within 12 months beforeevaluation. Postcholecystectomy syndrome was defined asany right upper quadrant pain in a patient who had had acholecystectomy for similar symptoms. In addition, anothergroup of 10 patients, who had had sphincter of Oddi man-

ometry as part of an evaluation for obscure abdominal painand who ultimately were found to have no evidence oforganicdisease, were used as normal control subjects for the purposeof comparing sphincter pressures.

After a thorough history and physical examination, all studypatients were evaluated by laboratory tests that included CSC,SMA-12, serum and urine amylase, serum lipids, and liverfunction determination, and by upper gastrointestinal radiog­raphy, cholecystography and/or intravenous cholangiog­raphy. Upper gastrointestinal endoscopy and ERCP were regu­larly performed. Sphincter of Oddi pressures were obtainedeither just before ERCP or at the time of upper gastrointestinalendoscopy.

Manometric Techniques. Sphincter of Oddi pressure wasmeasured directly using an infused manometric techniquethat has been previously reported. 3 Sphincter pressures weretransmitted through a teflon catheter 1.5 mm in diameter to anexternal transducer (Hewlett-Packard series 1280) and re­corded by a multi-channel direct writing instrument(Hewlett-Packard model 7788-A) in millimeters of mercury.The catheter was constructed'so that intraluminal pressureswere exerted through a lateral opening (0.8 mm in diameter)placed 2 mm from the catheter tip. During sphincter pressuremeasurement, the catheter was perfused with distilled waterusing an infusion pump (Harvard model 933) at a rate of 0.2mllminute.

Sphincter of Oddi manometry was performed in fastingpatients who had given their informed consent. Endoscopic

VOLUME 24, NO.1, 1977

From the Gastroenterology Branch, Department of Internal Medicine, and the ClinicalInvestigation Center, Naval Regional Medical Center, San Diego, California. Supported byBureau of Medicine and Surgery Clinical Investigation Program Project No. 3-16-029. Theopinions or assertions expressed herein are those ofthe authors and are not to be construed asofficial or as reflecting the views of the Navy Department or Naval Service at large. Reprintrequests, Otto T. Nebel, MD, 530 Lomas Santa Fe Drive, Solana Beach, California 92075.

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premedication included pharyngeal anesthesia withcetacaine spray and sedation with intravenousdiazepan (1 0 to20 mg). Duodenoscopy and cannulation ofthe papilla of Vaterwith a manometry catheter was performed as rapidly aspossible. The manometry catheter was positioned and main­tained in the area of peak pressure for a basal period of 5 to 15minutes. If duodenal hypermotility prevented cannulation,intravenous glucagon (0.5 to 1 mg) was given, and sphincterofOddi pressure was recorded 10 minutes following this injec­tion. Sphincter pressure was read directly from the tracing foreach minute of the test, and the individual sphincter of Oddipressure was taken as the mean of these 1-minute pressures.Student's T-test was used for statistical evaluation of thesedata.RESULTS Acute Pancreatitis. Preceding evaluation revealed astrong history of alcoholism in 9 patients and abdominaltrauma in1 patient. Cholelithiasis (1 patient) and gastric ulcer(1 patient) were other etiologic factors presumed responsiblefor precipitating the attack of acute pancreatitis. In 3 patients,no etiologic factor could be determined. Endoscopic retro­grade cholangiopancreatography was normal in 12 patientsand unsuccessful in 1 patient. Abnormal pancreatic ductswere seen in 2 patients (one patient having been injured andanother with early chronic pancreatitis).

Sphincter of Oddi pressures, obtained in all of these pa­tients, ranged from 22 to 60 mm Hg. The mean of 40±4 mmHg (mean :±:SE) was significantly greater (P<.01) than thatfound in control subjects (31:±:2 mm Hg.) 2(Figure 1).

Of additional note in this group was the 1 patient whosesphincter of Oddi pressure (56 mm Hg) was greater than 2standard deviations of the mean (Figure 2). This alcoholicpatient surreptitiously continued to drink during the studyperiod and on the day of sphincter of Oddi pressure determi­nation was discovered to have a blood alcohol of 0.12 mg.

Recurrent pancreatitis. The following etiologically impor­tant factors precipitated bouts of recurrent pancreatitis in the21 patients studied: alcoholism (9 patients), choledocho­lithiasis (3 patients), sphincter of Oddi stenosis (2 patients),hyperlipemia (1 patient), and duodenal lymphoma (1 patient);in 5 cases the causes were unknown.

In 2 patients, ERCP was unsuccessful, and in 8 patients,nprmal pancreatograms were obtained. Abnormal lesions

II

so

II

II

"MAL ACUTE .1l~T POST,~ITI' JllUCMA1J11I Q.

Figure 1. Mean sphincter of Oddi pressure (mm Hg) in 10 normalsubjects, '5 patients with acute pancreatitis, 21 patients with recur­rent pancreatitis, and 14 patients with post cholecystectomy syn­drome. The vertical lines indicate ±ISE of the mean.

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III

•.. •SOP

to

mmHg

+.."2'

ACUT~ II~CUIUI~NT POSTPANCII~ATIS PANCII~ATITIS G.

Figure 2. Mean sphincter of Oddi pressures (mm Hg) in the 3 studygroups. The vertical lines indicate .2 SO of the group mean. The dotsrepresent 3 patients whose sphincter pressures fell outside 2 SO oftheir group mean.

discovered by this technique included chronic pancreatitis (4patients), choledocholithiasis (3 patients), nonspecific pan­creatic duct deformity (2 patients), and pancreatic ductalobstruction (2 patients). Of interest is that only 1 of the 3patients with choleodocholithiasis had an abnormal intrave­nous cholangiogram as indicated by the radiologic report.

Manometric studies were obtained in all patients. Sphincterof Oddi pressures ranged from 24 to 90 mm Hg. The meansphincter of Oddi pressure of 50±6 mm Hg was significantlygreater(P<.01) than that in control subjects (31±6 mm Hgwassignificantly greater (P<.01) than that in control subjects(31:±:2 mm Hg). (Figure 1).

Included in this second group of patients were 2 patientswhose sphincter pressures were greater than 2 standard devia­tions of the mean (80 and 90 mm Hg) (Figure 2). Both of thesepatients were subsequently proven to have sphincter of Oddistenosis at the time of surgery.

Postcholecystectomy syndrome. Preliminary evaluation ofthe 14 patients who presented with right upper quadrantabdominal pain and who had a history of a previous cholecys­tectomy revealed no evidence of organic disease in 10; 3 werefound with choledocholithiasis. One patient had both recur­rent pancreatitis, right upper quadrant pain, and a history ofprevious cholecystectomy for cholelithiasis. This patient wasincluded in the 21 patients with recurrent pancreatitis and wasexcluded from the postcholecystectomy group.

Eight patients had normal ERCP's; 3 had cholangiogramsshowing choledocholithiasis, 1 had a pancreatogram showingnonspecific ductal deformity, and in 2 patients radiographywas unsuccessful.

Mamometry in the 14 patients with the postcholecystec­tomy syndrome revealed that the mean sphincter of Oddipressure of 38:±:4 mm Hg. was not significantly different(P>.05) from the 31:±:2 mm Hg. found in the control subjects.(Figure 1).

Complications. A total of 59 manometric studies wereperformed in 50 patients. One patient developed a mild,self-limited pancreatitis. No late complications were noted.DISCUSSION Although anatomically more than 1 sphincteric

GASTROINTESTINAL ENDOSCOPY

area may exist at the choledochoduodenal junction, man­ometrically only 1 high pressure zone can be distinguished inthis region.'" Whether endoscopic manometry is simply notsensitive enough to pick up subtle differences in high pressurezones or the sphincter behaves physiologically as a singlezone remai ns to be clarified by precise manometry of both thepancreatic and biliary systems.

The infused manometric system has proven to be an accu­rate and reliable method of determining the force of sphincterc1osure. 4 Currently, considerable controversy exists regardingthe most accurate method of recording sphincter pressure, andthese discussions have considerable importance when ap­plied to sphincter of Oddi manometry.' Recent studies havesuggested that the rapid pull-through method is more reliablethan the station pull-through method.' In orderto use the rapidpull-through method, the manometric system must be sensi­tive and capable of recording rapid changes in sphincterpressure. Sensitivity using infused manometry is determinedby a number of factors, but pump compliance and infusionspeed are the most important. Using currently availableequipment, increasing the infusion speed is the easiest way toincrease recording sensitivity. Unfortunately, because of thesmall diameter of the catheter used to record sphincter ofOddipressure, increased infusion speed causes significant in­creases in pressure caused by the internal resistance to theflow of water. Although these increases in pressure are theoret­ically constant, small changes in infusion speed caused by afaulty pump may cause significant changes in the recordedpressure. Because of this, we have used infusion speeds in therange of 0.2 ml/minute which has been found to minimize theeffect of pressure caused by catheter resistance.' Anotherapproach to the problem of measuring sphincter pressure hasbeen the development of miniature transducers. A smalltransducer has been adapted for recording sphincter of Oddipressures and is the subject of a preliminary report.· Thiscatheter has the advantage of extreme sensitivity and willrecord the slightest increases in pressure from 0 to 400 mg Hgat a rate greater than 1 mm per millisecond. Unfortunately, thispressure catheter is somewhat stiff, fragile, and seldom isusable after a few passages through the duodenoscope.

The infused system, on the other hand, has the advantage ofruggedness and is relatively inexpensive. We have, therefore,used the infused manometric system exclusively for humanendoscopy and have used the station pull-through methodwith slow infusion speeds as the procedure of choice inrecording sphincter pressure.

The increased sphincter of Oddi pressures found in patientswith acute and recurrent pancreatitis raise the age-old ques­tion of cause-versus-effect. The elevated values suggest thatsphincter spasm or hypertonicity was present at the time of ourevaluation. Due to the potential hazards of cannulation duringan acute attack of pancreatitis, the sphincter studies wereperformed at least 2 weeks following an attack and do notreflect sphincter tonicity during an acute attack. However,serial sphincter of Oddi measurements obtained in the weeksfollowing an attack might better elucidate the causative role ofsphincteric hypertonicity in pancreatitis.

The normal sphincter of Oddi pressure measurementsfound in patients with the postcholocystectomy syndromesupport the belief that sphincter malfunction is not an etiologi­cally important factor in producing the syndrome.

VOLUME 24, NO.1. 1977

A number of questions regarding the pathologic signifi­cance of increased sphincter of Oddi pressure were raised byanalysis of the manometric data obtained from the 3 patientswho had significantly elevated sphincter pressures. Elevatedsphincter pressures, on 2 separate determinations, obtained ina patient with acute and chronic alcoholism suggest a phar­macologic action of alcohol on the sphincter of Oddi. Thisaction has been postulated to exist for some time and is thebasis for the theory of ductal obstruction as an importantetiologic factor in alcohol-i nduced pancreatitis. Furtherstudies, including serial sphincter of Oddi manometry duringalcohol withdrawal, as well as serial intrapancreatic ductpressure determinations, may shed new light on this condi­tion. The 2 patients with recurrent pancreatitis and sphincterof Oddi pressures greater than 2 SD of their group are also ofconsiderable interest as they were both discovered to havesphincter of Oddi stenosis at time of common duct explora­tion. Although fibrotic narrowing might not in itself be ex­pected to lead to sphincter hypertonicity, several explanationsmight be postulated. Perhaps fibrosis reduces the sphinctericdiameter allowing greater pressures to be developed, orperhaps the increased sphincter of Oddi pressures merelyrepresent the result of muscular irritability produced by thesame process that results in fibrosis. Whatever the explanationfor these observations, further manometric studies in patientswith sphincter of Oddi stenosis will have to be performed todetermine if sphincter manometry is a clinically reliablepreoperative test for sphincter of Oddi stenosis.

The absence of significant morbidity or mortality suggeststhat sphincter of Oddi manometry is a safe procedure. Be­cause the manometry catheter is passed through the sphincterinto the pancreatic and biliary ducts and small amounts ofwater are injected into these ducts, the possibi lity of ductalsepsis in patients with obstructed ducts must be kept in mind,and precautions such as those used in performing ERCPshould be observed.

Although the data demonstrate significant alteration insphincter of Oddi pressure in patients with acute and recurrentpancreatitis, the clinical use of this technique in the evaluationand treatment of patients remains to be evaluated.

ACKNOWLEDGEMENT The authors wish to acknowledge the contributions ofthe interns and residents assigned to the gastrointestinal branch during the studyperiod and the special assistance of Drs. Messian, Meadows, and Fornes inevaluating these patients.

REFERENCES1. BOYDEN EA: The sphincter of Oddi in man and certain representative

mammals. Surgery 1:25, 19372. OGOSHI K, NIWA M, HARA Y, NEBEl aT: Endoscopic pancreato­

cholangiography in the evaluation of pancreatic and biliary disease.Gastroenterology 64:210, 1973

3. NEBEl aT: Manometric evaluation of lhe papilla of Valero GastrointestinalEndoscopy 21: 126, 1975

4. WINANS C5, HARRIS LD: Quantitation of lower esophageal sphincter com-petence. Gastroenterology 52:773, 1967 .

5. DODOS WI. HOGAN WS, 5TEF J), MILLER WN, LYDON 5B, ARNDORFERRC: A rapid pull-through technique for measuring lower esophageal sphinc­ter pressure. Gastroenterology 68:437, 1975

6. VONDRASEK P, EBERHARDT G: 5emiconductors in recording of pressureduring endoscopy; preliminary report on the technique of measurement. Z.Gastroenterol 12(6): 453, 1974

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