Overview

Diseases of the pancreas and biliary tree are

common in the United States. An estimated 6

per 100,000 people are afflicted with common

bile duct stones, representing only a small fraction

of those with gallstones. There are approximately

57,400 newly diagnosed cases of malignancy of

the pancreas, gallbladder, or extrahepatic biliary

tract each year, and the prognosis is usually poor.

Pancreatitis can occur in an acute, acute recurrent,

or chronic pattern, with common etiologic factors

including alcohol consumption and

choledocholithiasis.

This report is the product of a systematic

literature review of the evidence on the diagnostic

and therapeutic effectiveness of endoscopic

retrograde pancreatography (ERCP) focusing on

four clinical conditions: common bile duct

stones, pancreaticobiliary malignancy, pancreatitis,

and abdominal pain of possible

pancreaticobiliary origin. In addition, the

evidence describing patient, procedure, or

operator determinants of complications of ERCP

is systematically reviewed. The evidence on the

prediction of common bile duct stones is

reviewed as well.

Reporting the Evidence

The clinical topic areas addressed in this

evidence report were developed by the planning

committee for the National Institutes of Health

State-of-the-Science Conference (January 2002)

on Endoscopic Retrograde

Cholangiopancreatography. For each major topic,

there are several key questions that address the

most pertinent diagnostic and therapeutic issues. 

Topic 1. Patients with known or suspected

common bile duct stones 

a. What is the diagnostic performance of

ERCP in detecting common bile duct

stones in comparison to alternatives?

Alternatives include endoscopic ultrasound

(EUS), magnetic resonance

cholangiopancreatography (MRCP), or

computed tomography cholangiography

(CTC). 

b. What are the outcomes of treatment using

ERCP strategies compared to using surgical

or medical management?

c. What is the diagnostic value of specific risk

factors or predictive models for assessing

the likelihood of having a common bile

duct stone?

Topic 2. Patients with known or suspected

pancreaticobiliary malignancy

a. What is the comparative diagnostic

performance of ERCP tissue sampling

techniques in establishing a tissue biopsy

diagnosis of pancreaticobiliary malignancy,

and how do these techniques compare to

alternative nonsurgical tissue sampling

techniques (e.g., endoscopic ultrasoundguided fine-needle aspiration [FNA] or

percutaneous FNA)?

b. What is the diagnostic performance of

ERCP in diagnosing the presence of

malignant pancreaticobiliary obstruction in

comparison to other imaging alternatives

(e.g., EUS or MRCP)?

Evidence Report/Technology Assessment

Number 50

Endoscopic Retrograde Cholangiopancreatography

Summary

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES • Public Health Service

Agency for Healthcare Research and Quality
c. What are the outcomes of treatment using ERCP

strategies to treat malignant pancreaticobiliary

obstruction compared to using surgical or interventional

radiology treatment? 

Topic 3. Patients with pancreatitis

a. What is the diagnostic performance of ERCP in

detecting underlying causes or complications of

pancreatitis that are amenable to treatment in

comparison to alternatives (e.g., EUS or MRCP)?

b. What are the outcomes of treatment using ERCP

strategies compared to using surgical or medical

therapy?

Topic 4. Patients with abdominal pain of possible

pancreaticobiliary origin

a. What is the diagnostic performance of ERCP with

sphincter of Oddi manometry in identifying a

pancreaticobiliary origin of pain in comparison to

alternatives (e.g., biliary scintigraphy, EUS, or MRCP)?

b. What are the outcomes of treatment using ERCP

strategies compared to using surgical or medical

therapy?

Topic 5. What patient, procedure, or operator factors are

determinants of complications of ERCP?

Methodology

The protocol for this review was designed prospectively to

define study objectives, search strategy, patient populations of

interest, study selection criteria, outcomes of interest, data

elements to be abstracted and methods for abstraction, and

methods for study quality assessment.

One reviewer performed primary data abstraction of all data

elements into the evidence tables, and a second reviewer

checked accuracy of the evidence tables. Disagreements were

resolved between the two reviewers, or if necessary, in

consultation with the Evidence-based Practice Center Director

or members of the Technical Advisory Group.

Search Strategy for the Identification of Articles

The National Library of Medicine (NLM) staff conducted a

comprehensive literature search for journal articles on ERCP

from the PubMed®/MEDLINE®, BIOSIS, EMBASE, and

SciSearch® databases with a publication date from 1980

through August 13, 2001. Articles which had been indexed to

the NLM Medical Subject Heading (MeSH®)

“cholangiopancreatography, endoscopic retrograde” as well as

those containing the following list of ERCP synonyms and

textword combinations were retrieved:

Endoscopic retrograde cholangiopancreatogr?

Endoscopic retrograde cholangio-pancreatogr?

Endoscopic retrograde pancreatocholangiogr?

Endoscopic retrograde pancreato-cholangiogr?

ERCP

ERCPs

Endoscopic retrograde cholangiogr?

ERC and endoscop?

ERC and cholangiogr?

Endoscopic cholangiogr?

Endoscopic retrograde pancreatogr?

ERP and endoscop?

ERP and pancreatogr?

Endoscopic pancreatogr?

Endoscopic cholangiopancreatogr?

Endoscopic cholangio-pancreatogr?

ECP and endosc?

ECP and cholangiogr?

Endoscopic pancreatocholangiogr?

Endoscopic pancreato-cholangiogr?

EPC and endoscop?

EPC and pancreatogr?

The “?” is a truncation symbol used to permit retrieval for

variant word endings, as cholangiopancreatography,

cholangiopancreatographic, etc.

Excluded from the search results were articles that:

• Were written in a foreign language.

• Did not have abstracts as a part of the online record in

any of the databases searched.

• Did not include human subjects.

• Contained reports of only a single case.

The literature search for Topic 1c on prediction of common

bile duct stones and for additional studies selected by the

secondary selection criteria for Topics 3 and 4 used a

streamlined search process to identify key articles addressing

the clinical issue of interest. Reference lists from these articles

were reviewed, focused MEDLINE searches were performed,

and related articles were identified. 

The Technical Advisory Group and peer reviewers for this

project were asked to inform the project team of any studies

relevant to the key questions addressed in this evidence report

that were not retrieved by either of the search strategies.

Search Results

The online searches of the PubMed, EMBASE, BIOSIS,

and SciSearch databases in conjunction with additional

citations identified through manual searching yielded a total of

5,698 titles and abstracts for review. Based on review of

abstracts, 789 articles were selected for review in full text.

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Approximately 117 of these articles were excluded as review

articles. Primary and secondary selection criteria were applied

to articles identified as potential clinical trial reports. This

process yielded a total of 149 included studies for the review of

evidence. 

Study Selection Criteria

Primary Selection Criteria

The selection criteria for all topics in this report were:

1. Full-length report in peer-reviewed medical journals. 

2. Published in English.

3. Reported outcomes relevant to this systematic review.

4. Where there were multiple reports of a single study,

only the report judged to be most recent and complete,

based on number of included patients and length of

followup, was included. If additional relevant outcomes

were included in the duplicate reports, these data were

abstracted and added to the data from the primary

report with citation to the supplementary articles.

5. Prospective in design, or if retrospective, enrolled

consecutive patients or used appropriate sampling

methods (e.g., case-control sampling method).

In order to keep readers informed of ongoing studies,

studies published only in abstract form since 1999 and judged

to be important are noted in this systematic review; but data

were not abstracted into the evidence tables. 

Studies of diagnostic performance met the following

additional selection criteria:

1. Compared ERCP and at least one of the relevant

diagnostic alternatives or compared two ERCP

alternatives.

2. Subjected at least 90 percent of participants to both

ERCP and the relevant diagnostic alternative.

3. Addressed a relevant patient population.

4. Included at least 25 subjects.

5. Reported sufficient information to be able to calculate

2x2 contingency tables of diagnostic performance.

Studies of therapeutic outcomes met the following

additional selection criteria:

1. Compared ERCP strategies with at least one of the

relevant therapeutic alternatives. 

2. Addressed a relevant patient population.

3. Included at least 25 subjects in each treatment group

being analyzed separately. 

4. Reported on at least one relevant outcome measure.

5. Were a contemporaneous comparison studies. If not

contemporaneous, the populations and treatment

settings were comparable. 

Studies of predictors of ERCP complications met the

following additional selection criteria:

1. Included a multivariable analysis of the relationship

between patient, procedure, or operator factors and

ERCP complications.

2. Enrolled at least 100 patients if a cohort study, or at

least 25 cases if a case-control study.

3. Addressed potential confounding variables in either the

selection of subjects or analysis.

Studies on the prediction of common bile duct stones met

the following additional selection criteria:

1. Reported the association of either (a) specific risk factors

of interest and the presence of a common bile duct

stone (specific risk factors of interest were jaundice, liver

function test results, and ultrasound finding of a dilated

common bile duct), or (b) a prediction rule or model

predicting likelihood of having a common bile duct

stone and the presence of a common bile duct stone.

2. Enrolled at least 100 patients.

3. Reported sufficient information to be able to calculate

2x2 contingency tables of diagnostic performance in the

prediction of presence or absence of a common bile

duct stone.

Secondary Selection Criteria

There was a paucity of literature that met the primary

selection criteria for questions on ERCP treatment of chronic

pancreatitis (Topic 3b) and ERCP treatment of chronic

abdominal pain of possible pancreaticobiliary origin (Topic

4b). In order to examine these questions, the original study

selection criteria were relaxed for these topics to include:

1. Randomized controlled trials or otherwise concurrently

controlled studies of an ERCP intervention compared

to a relevant therapeutic alternative, regardless of sample

size for pancreatitis. 

2. Single arm pre-post-intervention studies which selected

a well-defined population with a predictable natural

history ascertained by baseline evaluation over 3

months. These studies must also have used an

appropriate well-designed outcome measure over at least

6 months of followup. 

3
Outcomes of Interest

For diagnostic performance studies, the outcomes of interest

were test performance characteristics (i.e., sensitivity,

specificity) in diagnosing clinically relevant findings.

For therapeutic outcome studies, the primary outcomes of

interest include:

1. Measures of technical success (e.g., removal of stone,

relief of obstruction, cyst drainage, need for repeat

procedure or placement of stent).

2. Measures of clinical success (e.g., survival, quality of life,

performance scores, relief of jaundice, relief of infection,

symptom scores, or pain scores). 

3. Resource utilization (e.g., hospitalization, perioperative

care, return to work, intensity of post-procedure care).

4. Procedure-related morbidity (e.g., stent-related

problems, cholangitis, sepsis, sedation-related outcomes,

bleeding, perforation, pancreatitis, long-term effects of

sphincterotomy, mortality). 

For studies of factors predicting ERCP complications, the

primary outcomes of interest were measures of relative risk or

predictive value associated with patient, procedure, or operator

factors.

Study Quality Assessment

The approach to assessing the quality of evidence used

domains commonly recognized as important in the literature

on study quality. Quality criteria were developed for each of

the three types of studies included in this systematic review:

studies of therapeutic effectiveness; studies of diagnostic

performance; and multivariable regressions analysis. For many

topics addressed in this evidence review, studies meeting the

most rigorous standards of quality do not exist. Thus, the

main purpose of quality assessment in this systematic review is

to discriminate between the better and lesser quality studies in

the available evidence base. 

For studies of therapeutic efficacy, the approach to quality

assessment was adapted from that of the U.S. Public Health

Preventive Services Task Force. Study quality domains of

interest were: initial assembly of comparable groups (includes

adequacy of randomization and controls for confounders);

maintenance of comparable groups (includes attrition,

crossovers, adherence, contamination); comparable

performance of interventions; comparable measurements

(unbiased, reliable, and valid); and appropriate analysis of

outcomes (includes intent-to-treat analysis). A study was rated

as “Good” if it clearly met all quality parameters. A study was

rated “Fair” if it reasonably met these parameters and had no

fatal flaw. A study was rated “Poor” if it was fatally flawed on

one or more parameters (e.g, if comparable groups were not

assembled or maintained or outcome measures were invalid or

not applied equally among groups). 

For studies of diagnostic performance, criteria for assessing

study quality were developed using key references in the field

of study quality assessment. The selection criteria used for this

systematic review eliminated poor quality studies from

inclusion. Study quality domains of interest to discriminate

between good and fair quality studies were: enrollment of

representative subjects (includes appropriate spectrum of

patients, unbiased enrollment, complete enrollment of eligible

patients, accounting for all eligible subjects); ERCP interpreted

independently of diagnostic alternative; and diagnostic

alternative interpreted independently from ERCP. As relevant,

issues of suitability and interpretation of reference standards

are addressed qualitatively in the discussion of each question.

For multivariable logistic regression analysis studies, the

quality domains of interest were the degree of over-fitting

present in the multivariable models, the nature of statistical

reporting, and the use of procedures to establish internal

validity. Degree of over-fitting was assessed using the ratio of

the number of endpoints divided by the number of candidate

variables in the model and was classified as satisfactory (ratio

>10) to severe (ratio <4). 

Findings

Topic 1. Patients with known or suspected common bile

duct stones 

Diagnostic performance of ERCP compared to alternatives: 

• The search and selection process yielded 10 studies on

MRCP (total n=834), 9 studies on EUS (total n=601),

and 6 studies with 7 sets of findings on CTC (total

n=266), but reference standards were not consistent

among studies. 

• Individual studies were relatively small and unlikely to

have adequate power to detect a statistically significant

difference; and no studies reported tests of statistical

significance. Thus, it is not possible to determine with

confidence whether the diagnostic performance is

similar or poorer than ERCP or to accurately quantify

any difference.

• The evidence comparing EUS to ERCP employs a

reference standard that permits inferences regarding

comparative performance. The evidence suggests that

EUS is similar to ERCP in detecting common bile duct

stones.

• MRCP has a degree of concordance with ERCP that

results in sensitivities and specificities greater than 90

percent in most studies. Concordance of CTC with

4
ERCP appears to be lower, with sensitivities as low as

80 percent in some studies.

• The role of alternative tests in the management of

patients with suspected common bile duct stones

cannot be determined strictly by diagnostic

performance. The costs and risks of the tests, and the

costs and risks of actions based on test results, along

with the pretest probability of stones must all be

considered to determine the optimal management

strategy.

ERCP treatment strategies compared to surgical or medical

management:

• In order to evaluate ERCP treatment strategies, studies

must account for patients through the diagnostic and

treatment process, including additional procedures

needed when initial treatment fails, and total morbidity

of the alternative strategies. Overall, the literature is

very thin and spread out over many different

comparisons of interest, preventing strong conclusions

about any specific comparison of treatment strategies. 

• The limited evidence available suggests that:

laparoscopic common bile duct exploration may be

better than ERCP strategies to manage cholecystectomy

patients with the least resource use; definitive surgery

with cholecystectomy prevents long term complications

at acceptable short-term morbidity when compared to

sphincterotomy alone in high-risk surgical patients with

suspected common bile duct stones; and endoscopic

treatment of acute cholangitis reduces short-term

mortality when compared to emergency surgery.

• Limited evidence suggests that the following techniques

have similar stone removal rates and short-term

complications: intracorporeal and extracorporeal

lithotripsy methods for removing large common bile

duct stones; balloon dilation and sphincterotomy; and

needle-knife fistulotomy and needle-knife precut

papillotomy.

Diagnostic value of specific risk factors or predictive models

for assessing the likelihood of having a common bile duct

stone:

• The probability of a common duct stone is one

important factor in determining diagnostic and

treatment strategies. When preoperative probability is

high, ERCP may be preferred. When probability is low,

expectant management is preferred. Additional

diagnostic tests may be used to discriminate among

patients in the middle range of probability. The exact

probability cutoffs depend on the risks and benefits of

the diagnostic and treatment alternatives. The risk

factor or prediction model with the best receiveroperating characteristics (ROC) would make the best

decision rule if the cutoff threshold were set correctly. 

• Thirteen studies (total n=7,409) reported multiple

findings of sensitivities and specificities of a single or

combination of risk factors to predict the presence of

common bile duct stones. The single risk factors most

commonly assessed were: clinical jaundice or elevated

bilirubin, liver function tests, and ultrasound findings of

a dilated common bile duct. All have significant

associations with the presence of common duct stones,

but none have both high sensitivity and specificity. Of

the four studies testing prediction rules based on

combinations of risk factors, only one study was a

validation of an independently developed prediction

rule. Multivariable prediction rules appear to have

superior ROCs compared to individual risk factors.

• The absence of any risk factors for stones (or a

discriminant function indicating absence of stones) is a

very strong predictor of the absence of stones. Absence

of any risk factor produces probabilities of stones that

are in the same range as a negative ERCP exam in a

patient with risk factors for stones (0 percent to 17

percent).

Topic 2. Patients with known or suspected

pancreaticobiliary malignancy

Diagnostic performance of ERCP tissue sampling techniques

in establishing a tissue biopsy diagnosis of pancreaticobiliary

malignancy in comparison to each other and compared to

alternative nonsurgical tissue sampling techniques:

• Twelve studies comparing at least two tissue sampling

techniques were identified in this systematic review.

The available studies are limited by small size and do

not consistently compare techniques in the same group

of patients. Most studies do not report statistical tests,

so it is not possible to determine with confidence

whether reported differences in sensitivity are

significantly different. While available evidence is

suggestive, larger studies are needed to draw conclusions

on relative performance of tissue sampling techniques.

• The available evidence suggests that sensitivity for

detecting malignancy is similar or higher for brush

cytology vs. bile aspiration cytology, similar for fineneedle aspiration (FNA) cytology vs. brush cytology,

and similar or higher for forceps biopsy vs. brush

cytology. Using combinations of two or more sampling

techniques may increase overall sensitivity. No

comparative studies evaluated whether incremental

5
improvement could also be achieved by repeated

sampling using the same technique.

• In the absence of comparative studies of endoscopic

ultrasound (EUS)-FNA and ERCP-FNA, indirect

comparison of single-arm studies was attempted. Results

from 10 studies including at least 400 subjects with

pancreatic mass suggest a range of sensitivity in

detecting pancreatic malignancy of 60-94 percent with

a specificity of 100 percent. Two studies of ERCP-FNA

including 164 subjects with various pancreatobiliary

tumors reported sensitivities ranging from 25 percent

to 62 percent. While sensitivity reported in these

studies appears to be lower than that for EUS-FNA,

such a comparison is not valid due to differences in

study populations, cytology techniques, and study

settings.

Diagnostic performance of ERCP compared to alternatives

in detecting malignant pancreaticobiliary obstruction:

• The available evidence directly comparing ERCP with

either MRCP or EUS is modest in size and of varying

methodologic quality. The evidence comparing ERCP

with MRCP is some what stronger than that comparing

ERCP with EUS.

• Individual studies do not demonstrate statistically

significant differences in diagnostic performance for

ERCP vs. MRCP or for ERCP vs. EUS for

characterizing malignant strictures. In sum, the

available studies suggest that both MRCP and EUS

provide similar diagnostic performance as ERCP in

detecting pancreaticobiliary malignant obstruction.

Treatment outcomes using ERCP strategies to treat

malignant pancreaticobiliary obstruction compared to using

surgical or interventional radiology treatment: 

• Five studies compared endoscopic stent drainage with

surgical bypass for palliation of malignant obstructive

jaundice, and a randomized controlled trial of 204

patients provided the most robust evidence. There were

no significant differences in overall survival, relief of

jaundice, technical success, total hospitalization days, or

perioperative mortality. Major complications were

more frequent in the surgery group (11 percent vs. 29

percent, p=0.02); and stent replacement was required in

37 percent of patients treated with ERCP stents. 

• Two randomized controlled trials (total n=206) and one

nonrandomized trial (n=165) compared metal to plastic

stents placed by ERCP for palliation of biliary

obstruction due to malignancy. Both types of stents

offer initial relief of jaundice and the available evidence

does not conclusively show any difference in

perioperative adverse events. Overall patient survival is

not significantly different when stent occlusions are

treated with stent exchange as needed. Total resource

utilization including need for repeat ERCP, total

hospital days, and costs was reported to be lower with

metal stents compared with plastic stents.

• Six studies (total n=782), addressed preoperative

stenting compared to no stenting prior to surgery for

malignant pancreaticobiliary obstruction. The available

evidence is of poor methodologic quality and fails to

demonstrate that preoperative stenting improves health

outcomes. Few studies report overall complications

including both those related to the preoperative stent

and the surgery, and these suggest that when

complications of preoperative endoscopic stenting are

considered along with the perioperative complications

of surgery, preoperative stenting is associated with more

complications. Preoperative stenting does appear to

significantly improve elevated bilirubin and liver

function tests, but the available evidence does not

suggest that surgical outcomes are improved as a result. 

Topic 3. Patients with pancreatitis

Diagnostic performance of ERCP compared to alternatives

to detect underlying causes or complications of pancreatitis

that are amenable to treatment: 

• Three studies (total n=190) were found which met

selection criteria. Each study addresses a different

potential cause or complication of pancreatitis amenable

to treatment. The available evidence is insufficient to

compare ERCP and other diagnostic modalities for the

identification of treatable causes or complications of

pancreatitis.

Treatment outcomes of ERCP strategies compared to

surgical or medical therapy:

• For treatment of acute pancreatitis, three randomized

controlled trials (total n=554) compared early ERCP to

delayed or selective ERCP. The available evidence

suggests that early ERCP reduces complications in

patient populations with acute pancreatitis and signs

and symptoms suggesting biliary obstruction. In

patients with low likelihood of biliary obstruction,

delayed or selective ERCP permits many patients to

avoid the procedure, and may result in lower

complication rates. In addition, one retrospective

associational study of a Veterans Administration

database of patients with acute pancreatitis (n=2,075)

suggests that outcomes of ERCP treatment are similar

to those of surgery.

• For ERCP treatment in patients with acute recurrent or

chronic pancreatitis, study selection criteria were relaxed

as described above. Although the available evidence is

6
sparse and largely uncontrolled, it suggests that ERCP

treatment reduces emergency room visits and

hospitalization in patients with pancreas divisum and

acute recurrent pancreatitis. Evidence on ERCP

drainage of pseudocysts is also sparse and poorly

controlled, but suggests that pain relief with ERCP is

similar to results of surgery. 

Topic 4. Patients with abdominal pain of possible

pancreaticobiliary origin

Diagnostic performance of ERCP with sphincter of Oddi

manometry compared with alternatives to identify a

pancreaticobiliary origin of pain: 

• The available evidence is not sufficient to permit

conclusions on the diagnostic performance of biliary

scintigraphy for sphincter of Oddi dysfunction. The

body of evidence consists of three studies that included

only 54 patients with sphincter of Oddi dysfunction;

results of these studies cannot be synthesized due to

differences in populations and methodology. There was

substantial variability in the reported performance

characteristics of biliary scintigraphy.

Treatment outcomes of ERCP strategies compared to

surgical or medical therapy:

• Two randomized controlled trials (total n=128) show

that endoscopic sphincterotomy relieves pain in

patients with pancreaticobiliary pain, sphincter of Oddi

dysfunction, and elevated basal sphincter of Oddi

pressure on manometry (greater than 40mm Hg). The

results of five single arm studies (total n=183)

corroborate these data and suggest that patients with a

dilated common bile duct and/or delayed contrast

emptying may also benefit from endoscopic

sphincterotomy.

• There is insufficient evidence to determine whether

endoscopic sphincterotomy improves outcomes in

patients with normal manometry findings. For this

group, the small studies included in this review do not

report significant improvements in pain with

endoscopic sphincterotomy. 

Topic 5. What patient, procedure, or operator factors are

determinants of complications of ERCP?

• Thirteen studies reported on multivariable logistic

regression analyses of factors associated with

complications of ERCP. The four largest studies each

included more than 1,800 patients, and the total

number of complications observed in these studies

ranged from 98 to 229. Overall, the methodologic

quality of the available analyses is limited by overfitting, i.e., testing an excessive number of factors

relative to the number of complications observed.

Consequently, this literature is exploratory in nature.

Reported magnitudes of association are not reliable,

significant independent variables may have been

overlooked, and some significant associations may be

misleading. Moreover, the existing studies do not use

common, standardized definitions for the complications

and factors of interest. Thus, caution should be used in

drawing inferences for clinical practice from these

studies.

• Patient, procedure, and operator factors were identified

that were found to be significantly associated with

complications in several of the more robust studies.

Younger age (using various cut-offs, but generally 60

years or less) was significantly associated with total

complications and with pancreatitis; as was suspected

sphincter of Oddi dysfunction. Precut endoscopic

sphincterotomy was the procedure-related factor most

commonly associated with total complications or

pancreatitis; a significant association with difficulty in

cannulation was also reported, but less frequently.

Multiple pancreatic contrast injections were associated

with pancreatitis. For hemorrhage, the clearest

association was patient factors related to coagulopathy.

Case volume was the only operator-related factor found

to be significantly associated with complications. These

studies used various cut-offs to define lower volume

centers: one or fewer procedures per endoscopist per

week; fewer than 40 endoscopic sphincterotomies per

endoscopist per year; and fewer than 150 procedures

per year.

Future Research

Recommendations for future research include the following: 

• Rigorous studies are required in order to reliably

quantify the relative performance of diagnostic ERCP

compared to alternatives. Existing studies do not

consistently use common reference standards and

frequently do not report tests of statistical significance.

Thus, assumptions about equivalence or difference

among alternative diagnostic technologies are not

supported by robust empirical evidence. 

• Comparative studies of alternative diagnostic and

treatment strategies are urgently needed. It is

imperative to use a comprehensive approach to

outcomes assessment, taking into account the total

burden of morbidity and resource utilization. 

• Evidence on treatment of chronic pancreatitis and

relapsing or recurrent pancreatitis is sparse. Rigorously

designed controlled trials are needed to assess the

outcomes of treatment for this debilitating condition.

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• Risk factors for complications of diagnostic and

therapeutic ERCP have been explored using

multivariable model analysis. Such analyses generate

hypotheses for reducing complications, but cannot

demonstrate cause and effect. Thus, interventions

intended to reduce complications should incorporate

prospectively defined studies to evaluate the results.

Availability of Full Report

The full evidence report from which this summary was

derived was prepared for AHRQ by the Technology Evaluation

Center, an Evidence-based Practice Center, under contract

number 290-97-001-5. It is expected to be available in early

2002. At that time, printed copies may be obtained free of

charge from the AHRQ Publications Clearinghouse by calling

800-358-9295. Requestors should ask for Evidence

Report/Technology Assessment No. 50, Endoscopic Retrograde

Cholangiopancreatography. Internet users will be able to access

the report online through AHRQ’s Web site at: www.ahrq.gov.

AHRQ Pub. No. 02-E008

January 2002

ISSN 1530-440X