Endoscopic Retrograde Cholangiopancreatography (ERCP) 

Updated: Mar 25, 2021
Author: Ahmad Malas, MD; Chief Editor: Kurt E Roberts, MD 

Overview

Background

Endoscopic retrograde cholangiopancreatography (ERCP) is a technique that uses a combination of luminal endoscopy and fluoroscopic imaging to diagnose and treat conditions associated with the pancreatobiliary system. The endoscopic portion of the examination uses a side-viewing duodenoscope that is passed through the esophagus and stomach and into the second portion of the duodenum. (See Technique.)

With the scope in this position, the major duodenal papilla is identified and inspected for abnormalities. This structure is a protrusion of the hepatopancreatic ampulla (also known as the ampulla of Vater) into the duodenal lumen. The ampulla is the convergence point of the ventral pancreatic duct and the common bile duct (CBD) and thus acts as a conduit for drainage of bile and pancreatic secretions into the duodenum.

The minor duodenal papilla is also located in the second portion of the duodenum and serves as the access point for the dorsal pancreatic duct. Evaluation of the dorsal pancreatic duct with ERCP is rarely performed; indications are discussed below.

After the papilla has been examined with the side-viewing endoscope, selective cannulation of either the CBD or the ventral pancreatic duct is performed. Once the chosen duct is cannulated, either a cholangiogram (CBD) or a pancreatogram (pancreatic duct) is obtained fluoroscopically after injection of radiopaque contrast material into the duct. ERCP is now primarily a therapeutic procedure; thus, abnormalities that are visualized fluoroscopically can typically be addressed by means of specialized accessories passed through the working channel of the endoscope.

Because ERCP is an advanced technique, it is associated with a higher frequency of serious complications than other endoscopic procedures are.[1] Accordingly, specialized training and equipment are required, and the procedure should be reserved for appropriate indications.

A review by Freeman et al, using data from 2004, estimated that about 500,000 procedures were performed annually in the United States.[2] However, because of a decrease in diagnostic ERCP with the advent of endoscopic ultrasonography (EUS) and magnetic resonance cholangiopancreatography (MRCP), this number is likely decreasing.

Indications

Since its first description in the late 1960s as a diagnostic technique,[3]  ERCP has evolved into an almost exclusively therapeutic procedure. The main reason for this evolution is that diagnostic modalities have been developed that are less invasive than ERCP but possess similar sensitivity and specificity for disease processes of the hepatobiliary system.[4]

Imaging techniques currently used in the diagnosis of hepatobiliary processes include computed tomography (CT), ultrasonography (US), EUS, and MRCP. The use of these modalities, in conjunction with pertinent clinical information (eg, the clinical history, physical examination findings, and laboratory data), can help select those patients for whom ERCP is most appropriate.

Because ERCP has a higher rate of severe complications than most other endoscopic procedures do, having an appropriate indication for its use is extremely important. In fact, most ERCP-related legal claims center on the aptness of the indication for the procedure.[5]  In 2005, the American Society for Gastrointestinal Endoscopy (ASGE) published guidelines regarding the role of ERCP in biliary tract and pancreatic diseases.[6]  The guidelines were updated in 2015 to include the following recommendations for benign biliary tract disease[7] :

  • Diagnostic ERCP should not be undertaken to evaluate pancreaticobiliary-type pain in the absence of objective abnormalities on other pancreaticobiliary imaging or laboratory studies (moderate-quality evidence)
  • Routine ERCP before laparoscopic cholecystectomy is contraindicated if there are no objective signs of biliary obstruction or stone (moderate-quality evidence)
  • In patients with acute biliary pancreatitis, ERCP should be reserved for those with concomitant cholangitis or biliary obstruction (high-quality evidence)
  • ERCP with dilation and stent placement is recommended for benign biliary strictures (moderate-quality evidence)
  • ERCP should be performed as first-line therapy for postoperative biliary leakage (high-quality evidence)
  • Cholangioscopy should be considered as an adjunct in the management of difficult bile duct stones that are not amenable to removal after sphincterotomy with or without balloon dilation or mechanical lithotripsy (low-quality evidence)
  • Cholangioscopy with directed biopsy should be considered as an adjunct for characterizing biliary strictures (low-quality evidence)
  • ERCP with sphincterotomy is recommended for patients with type I sphincter of Oddi dysfunction (SOD; moderate-quality evidence)
  • ERCP is not recommended for evaluation or treatment of type III SOD (high-quality evidence)
  • Rectal indomethacin with or without pancreatic stenting is recommended for prophylaxis against post-ERCP pancreatitis (PEP) when ERCP is performed in the setting of suspected SOD (moderate-quality evidence)

In June 2019, the ASGE issued a guideline for the use of ERCP in the evaluation and management of choledocholithiasis,[8]  which included the following recommendations:

  • In patients with gallstone pancreatitis without cholangitis or biliary obstruction/choledocholithiasis, urgent (< 48 hours) ERCP is not recommended.
  • In patients with large choledocholithiasis, large-balloon dilation after sphincterotomy is suggested rather than endoscopic sphincterotomy alone.
  • For patients with large and difficult choledocholithiasis, intraductal therapy or conventional therapy with papillary dilation is suggested.
  • Same-admission cholecystectomy is recommended for patients with mild gallstone pancreatitis.
  • To minimize the risk of diagnostic ERCP, the following high-risk criteria are suggested to directly prompt ERCP for suspected choledocholithiasis:(1) CBD stone on US or cross-sectional imaging or (2) total bilirubin >4 mg/dL and dilated CBD on imaging (>6 mm with gallbladder in situ)* or (3) ascending cholangitis. In patients with intermediate-risk criteria—abnormal liver tests or age >55 years or dilated CBD on US—EUS, MRCP, laparoscopic intraoperative cholangiography (IOC), or laparoscopic intraoperative US is suggested for further evaluation. For patients with symptomatic cholelithiasis without any of these risk factors, cholecystecomy without IOC is suggested.
  • Preoperative or postoperative ERCP or laparoscopic treatment is suggested for patients at high risk of choledocholithiasis or positive intraoperative cholangiopancreatography, depending on local surgical and endoscopic expertise.
  • For patients with Mirizzi syndrome, per-oral cholangioscopic therapy may be an alternative to surgical management, depending on local expertise; however, gallbladder resection is needed regardless of strategy. For hepatolithiasis, a multidisciplinary approach that includes endoscopy, interventional radiology, and surgery is suggested.
  • Plastic and covered metal stents may facilitate removal of difficult choledocholithiasis but require planned exchange or removal.

Indications for benign pancreatic disease in the 2015 ASGE guidelines included the following[9] :

  • Evaluation of idiopathic acute recurrent pancreatitis (suspected type 2 pancreatic SOD) when findings on EUS or MRCP are normal and not suspicious for biliary stones, sludge, or chronic pancreatitis; ERCP with empiric biliary or pancreatic sphincterotomy is an alternative
  • Biliary and/or pancreatic sphincterotomy is recommended for type 1 pancreatic SOD or type 2 pancreatic SOD confirmed by manometry
  • Rectal indomethacin and/or pancreatic duct stenting is recommended for prevention of PEP in high-risk patients
  • Treatment (with dilation or stent placement) of symptomatic dominant pancreatic duct strictures 
  • Pancreatic duct leakage

ERCP may also be indicated for treatment of symptomatic pancreatic pseudocysts (see the image below) or benign pancreatic fluid collections.[10]

Pancreatic stent placement for pseudocyst drainage Pancreatic stent placement for pseudocyst drainage. Used with permission from the Johns Hopkins Division of Gastroenterology and Hepatology (www.hopkinsmedicine.org/gi). Illustration Copyright© 1998-2003 by The Johns Hopkins Health System Corporation and The Johns Hopkins University. Illustration created by Mike Linkinhoker.

Indications for diagnosis of pancreatic malignancies include the following[11] :

  • Pancreatoscopy
  • Bile duct brushing and biopsy
  • Intraductal US
  • Diagnosis and characterization of suspected main-duct intraductal papillary mucinous neoplasms (IPMNs) [12]

Indications for ampullary disease include the following:

  • Assessment and treatment of ampullary adenomas [13]
  • Assessment of ampullary malignancy

Contraindications

Absolute contraindications for ERCP include the following:

  • Patient refusal to undergo the procedure
  • Unstable cardiopulmonary, neurologic, or cardiovascular status
  • Existing bowel perforation

Structural abnormalities of the esophagus, stomach, or small intestine may be relative contraindications for ERCP. Examples are acquired conditions such as esophageal stricture, paraesophageal herniation, esophageal diverticulum, gastric volvulus, gastric outlet obstruction, and small-bowel obstruction. An altered surgical anatomy, such as is seen after partial gastrectomy with Billroth II or Roux-en-Y jejunostomy, may also be a relative contraindication for ERCP.

Several factors play a role in choosing the best approach for ERCP access in patients with altered surgical anatomy in cases where ERCP is indeed indicated. These factors include long versus short Roux limb, native papilla versus bilioenteric anastomosis, prior sphincterotomy, anticipated accessory use (eg, sphincter of Oddi manometry), surgical risk, likelihood of repeat procedures, and possibility of internal hernias.

The different approaches in patients with Roux-en-Y anatomy include the following[14, 15] :

  • Duodenoscope through the anatomic route
  • Colonoscope or enteroscope through the anatomic route
  • Single- or double-balloon enteroscope
  • Spiral/rotational enteroscope
  • ERCP through gastrostomy or jejunostomy
  • Laparoscopically assisted ERCP
  • Biliary access obtained by interventional radiology

EUS-guided biliary access has been described in cases of difficult primary cannulation of a native papilla or in the appropriate setting with altered surgical anatomy.[16]  (See the image below.)

Endosonography-guided cholangiopancreatography. Us Endosonography-guided cholangiopancreatography. Used with permission from Baishideng Publishing Group, Inc (Fig 1 from Perez-Miranda M, de la Serna C, Diez-Redondo P, Vila JJ. Endosonography-guided cholangiopancreatography as a salvage drainage procedure for obstructed biliary and pancreatic ducts. World J Gastrointest Endosc. Jun 16 2010;2(6):212-22).

The presence of acute pancreatitis is typically considered a relative contraindication as well, unless the etiology of the pancreatitis is gallstone-related and the therapeutic goal is to improve the clinical course by means of stone extraction.[17, 18]  In addition, ERCP with sphincterotomy or ampullectomy is relatively contraindicated in coagulopathic patients (international normalized ratio [INR] >1.5 or platelet count < 50,000/µL).

Technical Considerations

Best practices

Before ERCP, all of the patient’s previous abdominal imaging findings (from CT, magnetic resonance imaging [MRI], US, and cholangiography or pancreatography) should be reviewed; this can facilitate location of the pathology during ERCP, as well as help pinpoint any changes that occurred since the previous imaging was performed.

A scout radiograph should be obtained while the patient is on the fluoroscopy table and before insertion of the duodenoscope; this image can act as a baseline for comparison with subsequent fluoroscopic images taken after contrast injection.

The patient's surgical history should be reviewed before the procedure to determine whether there is anything in the surgical anatomy that may be a contraindication for ERCP.

To minimize the patient's exposure to radiation, fluoroscopic images should be obtained only as necessary during the procedure; some fluoroscopy machines can be adjusted to minimize the frequency of image acquisition.

Deep sedation is desirable during ERCP because a stable endoscopic position in the duodenum is important for proper cannulation, therapeutic intervention, and avoidance of complications.

If the pancreatic duct is cannulated several times or if contrast is injected into the pancreatic duct, placement of a temporary pancreatic duct stent or rectally administered nonsteroidal anti-inflammatory drugs (NSAIDs; eg, indomethacin or diclofenac) should be considered in order to decrease the risk of PEP.[19] These two prevention modalities have proved effective for PEP prophylaxis. Numerous other pharmacologic agents have been studied, including gabexate, somatostatin, octreotide, steroids, heparin, allopurinol, and nitroglycerin, but with disappointing results.[20]

Multiple randomized controlled trials and meta-analyses have shown rectally administered NSAIDs to be effective in reducing the incidence of PEP, the occurrence of moderate-to-severe pancreatitis, and the length of hospital stay in high-risk patients who develop PEP.[21, 22, 20, 23, 19]  Indirect comparative effectiveness studies suggested that rectal NSAIDs alone may be superior to pancreatic duct stenting in preventing PEP as a simple, easily administered, safe, inexpensive, and effective treatment modality,[23]  but there remains a need for further studies to help confirm these results through direct comparison with prospective randomized controlled data.

Whether rectal NSAIDs should be given to all patients or employed selectively in high-risk patients is a topic of debate among experts. Widespread adoption of this simple strategy may minimize the incidence of PEP and modulate its severity, resulting in major clinical and economic benefit.[20, 19]  NSAIDs have been shown to inhibit prostaglandin synthesis, phospholipase A2 activity, and neutrophil/endothelial cell attachment, which are all believed to play a key role in the pathogenesis of the initial inflammatory cascade of acute pancreatitis.[21, 24, 25, 20]

Single-dose administration is not associated with enhanced risk of bleeding or renal insufficiency. Rectal administration seems to work better than other routes, including oral, intramuscular (IM), intravenous (IV), and intraduodenal.[20]

In a prospective randomized study (N = 162) designed to compare the efficacy of single-dose (n = 87) and double-dose (n = 75) rectal indomethacin administration for preventing PEP, Lai found that although the incidence of PEP was lower in the latter group, the difference was not significant.[26] They concluded that in the general population, single-dose rectal indomethacin immediately after ERCP is sufficient for prevention, but they noted that in cases of difficult cannulation, the incidence of PEP frequency may rise as high as 15.4% even when rectal indomethacin is used.

The optimal timing of administering rectal NSAIDs has not been clearly defined. Two meta-analyses found no difference in efficacy between giving the medication before the procedure and giving it immediately afterward.[20, 19]

A pilot study suggested that aggressive IV hydration with lactated Ringer solution (LR) may reduce the development of PEP and is not associated with volume overload.[27]

In a subsequent prospective randomized, double-blind, placebo-controlled trial, 192 patients at high risk for PEP received standard normal saline solution (NS) plus placebo (n = 48), NS plus indomethacin (n = 48), LR solution plus placebo (n = 48), or LR solution plus indomethacin (n = 48).[28] The primary outcome was PEP; secondary outcomes were severe acute pancreatitis, localized adverse events, death, length of stay, and readmission. The combination of LR solution and indomethacin led to reductions in PEP incidence and readmission rate as compared with the combination of NS and placebo.

Complication prevention

The first step in preventing post-ERCP complications is to identify those patients who are most likely to experience adverse events.[1] Factors that place patients at higher risk for PEP, the most common serious complication associated with this procedure, may be broadly grouped as follows:

  • Patient-related factors
  • Procedure-related factors
  • Operator-dependent factors
  • Underlying disease or indication for performing ERCP

It is important to distinguish between asymptomatic postprocedural pancreatic enzyme elevations of serum amylase and lipase, which can be seen in more than half of all patients undergoing ERCP in the first 24 hours after the procedure, and true clinical pancreatitis induced by the ERCP, which presents with pancreatic-type pain or cross-sectional imaging confirming inflammation.[25]

Proposed underlying mechanisms that can induce PEP include the following[21, 25] :

  • Thermal injury from electrocautery
  • Hydrostatic injury from overinjection of the pancreatic duct
  • Enzymatic injury from intestinal contents or contrast
  • Mechanical injury from prolonged manipulation around the papillary orifice causing edema

Patient-related factors include the following[21, 24, 25, 29] :

  • Younger age (< 50 years)
  • Female sex
  • History of acute or recurrent pancreatitis
  • History of PEP
  • Preexisting biliary-type pain
  • Presence of bile duct stones
  • Normal serum bilirubin
  • Documented or suspected SOD (especially type III dysfunction with normal bile duct size and normal liver tests)

The term SOD is used to define motility abnormalities caused by stenosis or dyskinesia of the sphincter of Oddi.[21]  A history of chronic calcific pancreatitis seems to confer a protective effect on the risk of developing PEP.[25]

Procedure-specific risk factors for PEP include the following[21, 23, 24, 25, 30] :

  • Difficult cannulation of the ampulla of Vater (>10 attempts)
  • Cannulation of the pancreatic duct
  • Injection of contrast into the pancreatic duct (>2 times)
  • Pancreatic duct sphincterotomy
  • Pancreatic acinarization (opacification of acini)
  • Pancreatic duct tissue sampling/brushing
  • Pneumatic dilation of an intact biliary sphincter
  • Precut sphincterotomy
  • Ampullectomy

Data support the use of prophylactic pancreatic duct stents or the administration of rectal NSAIDs in patients at increased risk for pancreatitis, because it has been shown to reduce the incidence of PEP in this high-risk cohort of patients.[31, 21, 24, 25, 22, 20, 23]

Operator-dependent factors include the following:

  • Low case volume
  • Lack of experience
  • Lack of good technique

The significance of low case volume in this setting was challenged by a multicenter prospective study showing that the risk of PEP was not associated with the case volume of either the single endoscopist or the center.[30]

Those at higher risk for post-ERCP hemorrhage include patients with either a pathologic or an iatrogenic coagulopathy. Anticoagulant or antithrombotic therapy should be discontinued before elective ERCP (generally 5-7 days beforehand), and the prothrombin time (PT) and partial thromboplastin time (PTT) should be evaluated on the day of the procedure. If the PT and PTT are significantly abnormal, the procedure should be rescheduled if it is not an emergency. If there is an urgent need for ERCP, reversal of the coagulopathy with fresh frozen plasma may be required.

Routine use of prophylactic antibiotics in elective ERCP is controversial. The infectious risks of ERCP (ie, bacteremia and cholangitis) are most likely to occur in patients who present with biliary obstruction.

The 2015 ASGE guidelines for antibiotic prophylaxis for gastrointestinal endoscopy recommended antibiotic therapy in all patients presenting with bile duct obstruction and acute cholangitis.[32]  They also recommended antibiotics in cases where drainage with ERCP is incomplete or is achieved with difficulty (eg, in patients with hilar cholangiocarcinoma and primary sclerosing cholangitis).

A Cochrane analysis of nine randomized clinical trials found that the rates of bacteremia and cholangitis were lower in patients who received prophylactic antibiotics before elective ERCP than in those who did not, though subgroup analysis demonstrated that the effect of antibiotics was less evident in patients who underwent uncomplicated ERCP with successful biliary drainage.[33]

In March 2015, the American Gastroenterological Association suggested the following recommendations for reducing endoscope-associated infections in ERCP[34] :

  • Treat all elevator-channel endoscopes the same, including both fine-needle aspiration echoendoscopes (endoscopic ultrasound) and duodenoscopes
  • Track elevator-channel endoscopes by patient and by device serial number to facilitate retrospective identification in case of infection
  • Use a two-phase infection surveillance program that tracks all patients who have had a procedure with an elevator-channel endoscope, and periodically collect culture surveillance of all elevator-channel endoscopes; a positive culture should trigger a review of reprocessing techniques
  • Use a standard device reprocessing training program, and require reprocessing staff to demonstrate competency every 6 months
  • Immediately contact the Centers for Disease Control and Prevention to aid in investigation of any suspected breach or infection

Most mucosal perforations occurring during ERCP are periampullary and are associated with sphincterotomy. Periampullary perforations are usually retroperitoneal and can often be managed with supportive care rather than immediate surgical intervention. This complication can be prevented in many cases by following proper landmarks while performing sphincterotomy and by taking care to not cut beyond the intraduodenal portion of the CBD.

Perforations occurring away from the ampulla are typically due to traumatic endoscope passage, often related to limited visualization of the lumen.

As a general rule, the duodenoscope should never be forced against significant resistance during insertion. The forceps elevator should be in the closed position during passage of the endoscope down the lumen because it may lacerate the adjacent tissue if left in the open position.

Outcomes

Because of inherent bias and patient underreporting, an accurate estimate of the procedural complication rate is difficult to obtain. However, comparisons with complication data pertaining to other endoscopic procedures makes it clear that ERCP is associated with approximately fourfold higher rates of severe complications.[35]

In a study of post-ERCP complications that pooled prospective patient survey data from almost 17,000 patients undergoing the procedure, ERCP-related morbidity secondary to pancreatitis, bleeding, perforations, and infections was 6.85%, of which 5.17% was graded as mild-to-moderate and 1.67% as severe; ERCP-specific mortality was 0.33%.[36]  Pancreatitis was the most common complication (3.47% of patients), followed by infection (1.44%), bleeding (1.34%), and perforations (0.6%).

The incidence of PEP ranges from 1% to 10% in average-risk patients but can exceed 25-30% in certain high-risk patient populations. This wide range is due to the heterogenous interplay of multiple patient-, procedure-, and operator-related factors.[24]  Acute PEP is not a uniform disorder and varies in intensity. Most cases are mild and resolve with proper treatment without any permanent sequelae.[25]

The relatively high risk associated with ERCP underscores the importance of having this procedure performed by experienced practitioners. It also helps explain the trend toward therapeutic as opposed to diagnostic ERCP. Although the absolute complication risk is greater with therapeutic ERCP than with diagnostic ERCP, the potential benefits are also greater, and the risk-to-benefit ratio favors therapeutic ERCP.[37, 38, 39, 29]

ERCP has not been as thoroughly studied in infants and children as it has in adults, though some reports have suggested its safety in this context. In a retrospective series of 244 procedures performed in 158 patients younger than 18 years (including 56 procedures in 53 infants [< 1 year]), Åvitsland et al noted only two cases of infection and no instances of PEP in infants; in older children (>1 year), the incidence of PEP was 10.4%.[40]

 

Periprocedural Care

Equipment

Endoscope (side- or forward-viewing)

The standard endoscope for endoscopic retrograde cholangiopancreatography (ERCP) is the therapeutic side-viewing duodenoscope, which has a side-viewing objective lens, a tip with four-way angulation capability, a side-positioned air/water nozzle, a 4.2-mm instrument channel, and a forceps elevator adjacent to the instrument channel outlet that allows fine linear instrument position changes (see the images below).

View of duodenoscope tip. Note that elevator is in View of duodenoscope tip. Note that elevator is in closed position and is obscuring instrument channel from view.
Side-viewing endoscope. Used with permission from Side-viewing endoscope. Used with permission from the Johns Hopkins Division of Gastroenterology and Hepatology (www.hopkinsmedicine.org/gi). Illustration Copyright© 1998-2003 by The Johns Hopkins Health System Corporation and The Johns Hopkins University. Illustration created by Mike Linkinhoker.

In certain situations where a traditional duodenoscope is not suitable (eg, in patients with a Billroth II or a Roux-en-Y reconstruction), a forward-viewing endoscope may be tried instead.[41]

Image-processing equipment

Appropriate endoscopic video processing equipment is needed in a procedure room that can also accommodate fluoroscopy. Most centers have a dedicated procedure room that incorporates either a permanent fluoroscopy table or a portable C-arm device, along with the video processing equipment specific to a particular brand of endoscope. Dual video monitors or split-screen capability must be available in the endoscopist's direct field of view; simultaneous fluoroscopic and endoscopic imaging is required for proper completion of ERCP (see the image below).

Fluoroscopy table and dual-screen procedure monito Fluoroscopy table and dual-screen procedure monitors.

Fluoroscopic imaging in ERCP requires the injection of a radiopaque marker into either the biliary tree (cholangiography) or the pancreatic duct (pancreatography). Iodinated contrast agents are most commonly used, though noniodinated agents are also available. Undiluted contrast is appropriate for initial fluoroscopic images or when fine imaging details are desired (as in visualizing the pancreatic duct). Half-strength contrast is preferable for certain purposes, such as assessment for choledocholithiasis in a dilated bile duct.

Because of concerns over systemic uptake of iodinated contrast agents during ERCP, prophylactic steroid and diphenhydramine therapy before contrast administration is a common practice in patients with a history of hypersensitivity to such agents. Although prophylactic medication and substitution of noniodinated contrast are reasonable, a trial demonstrated no adverse reactions to iodinated contrast agents during ERCP in high-risk patients, suggesting that these preventive measures may be unnecessary in this patient population.[42]

Cannulation devices

Most endoscopists have adopted the sphincterotome as their primary cannulation device for ERCP, primarily because this device has the ability to cannulate both the biliary and pancreatic ductal system, as well as perform sphincterotomy, without having to be switched out. Most currently available sphincterotomes have multiple lumens that allow the passage of a guide wire or injection of contrast.

Current sphincterotomes also have a cutting wire of varying length that both allows coagulative cutting and has the ability to alter the curvature of the radiopaque tip of the device. Tension can be applied to the cutting wire via an operator-controlled handle, which causes the tip of the sphincterotome to bow (see the image below); this ability to bow and unbow the tip of the device can facilitate cannulation and cutting. Different tip diameters and degrees of taper are also available, depending on the clinical situation.

Sphincterotome in bowed position. Sphincterotome in bowed position.

Once the sphincterotome is in the proper position, most endoscopists use a wire-guided approach to cannulation, in which a guide wire is passed through one of the sphincterotome lumens and into either the common bile duct (CBD) or the pancreatic duct before contrast injection. This approach not only facilitates acquisition of ductal access but also allows accessories to be more safely passed into the ductal system over the wire.

Many different guide wires are available from several different manufacturers. They vary with respect to diameter (0.018-0.035 mm), length (260-cm short wire or 450-cm long wire), degree of rigidity, outer coating material, tip angle, and even bending or coiling tendency with the application of pressure. By taking these characteristics into account, one can readily choose the appropriate wire for a specific situation.

The cannulation catheter is a more traditional tool, which some endoscopists still prefer to the sphincterotome. A cannulation catheter is similar to a sphincterotome in that it often contains multiple lumens for contrast injection or wire passage and a radiopaque tip. It differs from a sphincterotome in that it has no cutting wire, but it can include a specialized tip (eg, a ball tip or needle tip) that can facilitate passage of the catheter into a duct with a particular structural property.

Therapeutic accessories

Once access to either the biliary or the pancreatic ductal system is gained, various accessories can be passed over the wire for use in therapeutic interventions. These accessories include tools that are specific to a certain indication, such as stone extraction balloons (see the video below) or baskets (see the first image below), stricture dilating balloons or catheters (see the second image below), stents of various types (see the third image below), cytopathology brushes, and even cholangioscopes for intraductal visualization.

This video, captured via endoscopic retrograde cholangiopancreatography, shows insertion of biliary extraction balloon over guide wire. Sweeps of common bile duct (CBD) are made with extraction balloon to remove stones, sludge, and debris from CBD. Video courtesy of Dawn Sears, MD, and Dan C Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.
Two different sizes of biliary stone baskets. Two different sizes of biliary stone baskets.
Biliary stricture–dilating balloon catheter. Biliary stricture–dilating balloon catheter.
Biliary stents. Upper stent is plastic stent; lowe Biliary stents. Upper stent is plastic stent; lower stent is self-expanding metal stent (SEMS).

Protective gear

All personnel within the ERCP procedural area should be protected from the scattered radiation produced by the fluoroscopy unit. Standard protective apparel includes a lead apron and a thyroid shield with a lead thickness of 0.2-0.5 mm. Two-piece lead apparel in the form of a skirt and vest is also available, depending on the wearer's preference. The use of leaded radiation safety glasses is also advocated; repeated radiation exposure to the eye can be hazardous.[43]

Additional protective gear recommended for use during ERCP includes a face shield, surgical gloves and gown, and shoe covers if desired.

Patient Preparation

Anesthesia

Acceptable regimens for achieving adequate sedation in patients undergoing ERCP vary by medical center and by provider and may also be dictated by the laws pertaining to anesthetic administration in a certain geographic region. The most common sedation protocol includes the use of a nurse-administrated or physician-administered intravenous (IV) benzodiazepine (eg, midazolam) along with an IV narcotic (eg, meperidine).

Meperidine is commonly used because of its longer half-life and deeper sedative properties and because of the traditional belief that other narcotic agents (eg, fentanyl or morphine) may be associated with contraction of the sphincter of Oddi. A prospective randomized double-blind trial demonstrated no difference in papillary cannulation rates between patients receiving propofol plus fentanyl and those receiving propofol alone.[44] Thus, fentanyl may be a reasonable alternative to meperidine, especially in patients who are allergic to meperidine.

For patients in whom deep sedation may be difficult to achieve with this approach (eg, those who use recreational or medicinal narcotics, alcohol, or sedatives and those who have a history of difficult sedation), general anesthesia should be considered. Many medical centers use an anesthetist to administer a general anesthetic agent (eg, propofol) in this scenario.

Certain states also allow trained nurses or gastrointestinal (GI) endoscopists to administer propofol. This trend may increase, now that nurse-administered propofol has been shown to be as safe as administration of midazolam plus meperidine for therapeutic endoscopic procedures.[45] The benefits of propofol, as compared with other agents, include rapid onset of action, deep sedation, and relatively rapid recovery.

Regardless of the anesthetic regimen, sedated patients are typically monitored by a nurse for respiratory and cardiovascular status during ERCP. Any of the agents mentioned above can be associated with respiratory or cardiovascular compromise; thus, antagonist agents (eg, naloxone for narcotics and flumazenil for benzodiazepines) should be readily available to the monitoring personnel. Antimotility medications (eg, glucagon) are also commonly used during ERCP to decrease bowel contractions/motility and facilitate proper visualization and cannulation of the ampulla in a patient with brisk duodenal peristalsis.

Positioning

The prone position (see the image below) is standard for ERCP because it offers the best access for anterior-posterior fluoroscopic imaging.

Prone position. Prone position.

Some endoscopists prefer the semiprone position (see the image below). Although this position may not yield optimal image quality, it may be preferable for certain patients (eg, those who are obese or have respiratory compromise). Some endoscopists also find it easier to pass the duodenoscope into the small bowel while the patient is in this position.

Semiprone position. Semiprone position.

The supine position (see the image below) may also be used for ERCP. Indications for the use of this position include endoscopist preference, comorbid conditions, pregnancy, and any factor that necessitates closer airway monitoring during the procedure.

Supine position. Supine position.
 

Technique

Approach Considerations

The main objectives of endoscopic retrograde cholangiopancreatography (ERCP) are to gain access to the biliary system or the pancreatic duct via the major duodenal papilla in the second portion of the duodenum, to obtain fluoroscopic images of either the biliary tree or the pancreatic duct after injection of a radiopaque contrast agent, to interpret those images in real time, and to perform therapeutic interventions as indicated.

Endoscopic Retrograde Cholangiopancreatography

Insertion of endoscope

With the patient in the prone or semiprone position, the duodenoscope is passed through a self-retaining mouth guard with the tip angled slightly downward to facilitate its movement to the level of the hypopharynx. Once the endoscope has reached this location, the tip is brought back to the neutral position, and gentle pressure is applied until passage into the proximal esophagus is achieved.

Care must be taken in passing the endoscope through the esophagus and into the stomach; visibility is limited. If attempts to pass the duodenoscope meet with resistance and no cause is visible, removal of the duodenoscope and subsequent examination with a gastroscope (standard forward-viewing endoscope) should be considered.

Gastric examination and duodenal positioning

Once the duodenoscope is in the gastric lumen, it is advanced to a position in which it lies on the mucosa of the greater curvature, allowing visualization of the lesser curvature and the distal stomach. With further advancement of the endoscope, the tip should pass the angular incisure. In this position, upward angulation of the tip should allow examination of the gastric cardia.

In the distal stomach, downward angulation of the tip should bring the pylorus into view. When the endoscope reaches the pylorus, the tip should again be placed in the neutral position, with the pylorus visible in the 6-o'clock location (“sun setting” position) as passage into the duodenal bulb is achieved.

The duodenoscope is advanced to the distal aspect of the first portion of the duodenum, and the tip is angled to the right and slightly upward. The scope is then carefully withdrawn with slight clockwise torque applied to bring the endoscope into the "short" position. (See the video below.)

This video, captured via endoscopic retrograde cholangiopancreatography, shows side-viewing duodenoscope being inserted and advanced into stomach and duodenum. Scope is then reduced into short position, bringing ampulla into view. Video courtesy of Dawn Sears, MD, and Dan C Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.

This maneuver should advance the endoscope to the second portion of the duodenum and permit visualization of the major duodenal papilla, which appears as a small pink protuberance at the junction of the horizontal and vertical duodenal folds (see the image below).

Endoscopic view of major duodenal papilla. Endoscopic view of major duodenal papilla.

Cannulation of major papilla

The key to successful cannulation of either the pancreatic or the biliary ductal system is proper scope positioning. With the duodenoscope in the short position in the second portion of the duodenum, the lens should be facing the papilla, with the tip in close proximity to the duodenal wall.

For easier cannulation of the common bile duct (CBD), the scope should be positioned so that the image of the papilla is in the upper portion of the video monitor; this allows an upward approach to the papilla, which is more in line with the natural path of the CBD. In contrast, cannulation of the pancreatic duct is more easily achieved via an approach that is more perpendicular to the duodenal wall.

If possible, the intraduodenal segment of the CBD should be observed before the initial attempt at cannulation so that the duodenoscope can be lined up with the natural contour of the bile duct. As a rule of thumb, for cannulation of the CBD, the cannulation device should be aimed in a slightly tangential direction to the 10- to 11-o'clock position; for cannulation of the pancreatic duct, the device should be pointed to the 1-o'clock position.

The traditional approach to cannulation, termed contrast-guided cannulation, involves passage of the cannulation device tip into the papillary orifice, followed by injection of contrast material to confirm proper positioning. However, there are data to support a wire-guided approach.

In the wire-guided approach, a guide wire is passed under fluoroscopy into either the pancreatic duct (see the video below) or the CBD before the injection of contrast. A systematic review and meta-analysis demonstrated a significantly lower incidence of post-ERCP pancreatitis (PEP), higher primary cannulation rates, fewer precut sphincterotomies, and no increase in ERCP-related complications with the wire-guided technique as compared with the contrast-assisted cannulation technique. Therefore, the guide wire–assisted cannulation technique has become the method preferred by most advanced endoscopists.[46, 47]

This video, captured via endoscopic retrograde cholangiopancreatography, shows cannulation of ampulla. Guide wire is then advanced, as seen on fluoroscopy, and wire makes right turn into pancreatic duct. Video courtesy of Dawn Sears, MD, and Dan C Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.

Several anatomic abnormalities may make cannulation of the bile duct more challenging. The most common of these anomalies, the presence of a periampullary diverticulum, occurs in approximately 7.5% of patients undergoing ERCP for any indication.[48]  Although the ampulla is typically adjacent to the rim of a diverticulum or between two diverticula, it may also be found inside the diverticular sac.

When the ampulla is located outside the diverticulum, the natural course of the CBD is often unaltered; however, when it is located inside the sac, this may not be the case, and proper alignment of the duodenoscope can be very challenging. In view of the risk of bowel perforation, considerable care should be taken in repositioning the duodenoscope in the presence of a diverticulum.

Another scenario that may make cannulation of the major papilla difficult is the presence of a distal ductal defect, such as an impacted biliary stone, a distal bile duct tumor or stenosis, or a pancreatic head mass. A wire-guided approach to cannulation is typically recommended in these circumstances. Cannulation with guide wires of varying diameter or stiffness may be necessary for successful entry into the system, depending on the clinical scenario.

The video below depicts cannulation of the ampulla (major papilla).

This video, captured via endoscopic retrograde cholangiopancreatography, shows engagement and cannulation of ampulla using biliary cannulation catheter. Video courtesy of Dawn Sears, MD, and Dan C Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.

Cannulation of minor papilla

Occasionally, cannulation of the minor papilla is desired to search for a possible anatomic anomaly (eg, pancreas divisum) or to perform a minor duct sphincterotomy in a symptomatic patient with known pancreas divisum.

Pancreas divisum is a congenital anatomic variant in which the ventral and dorsal pancreatic ducts fail to fuse. Although most patients with this variant are asymptomatic, a small subset of patients with pancreas divisum may present with idiopathic recurrent acute pancreatitis. In these symptomatic patients, minor duct sphincterotomy with possible stent placement may be beneficial (after other common causes of acute pancreatitis have been ruled out).

The minor papilla is generally located about 1-2 cm proximal to the major papilla in the second portion of the duodenum. It typically looks like a smaller version of the major papilla but may be difficult to visualize in some patients. It can be located by first visualizing the major papilla and then slowly withdrawing the scope while looking slightly to the right. Cannulation of the minor duct usually requires a smaller cannulating device (eg, a cannulation catheter with a needle tip) and the use of a wire-guided approach before contrast injection.

Fluoroscopic imaging

Once passage of a guide wire into either the CBD or the pancreatic duct has been confirmed by means of fluoroscopy, the cannulation device is advanced into the duct, and a radiopaque contrast agent is injected.

With the patient in the prone, semiprone, or supine position either on a dedicated fluoroscopy table or under a portable C-arm device, a cholangiogram or a pancreatogram is obtained by the endoscopist (see the image below). This measure allows immediate assessment for ductal structural abnormalities or filling defects (eg, from stones; see the video below). If intervention is required, accessories can be passed over the guide wire into the duct with the help of fluoroscopy.

Cholangiogram. Note (a) duodenoscope positioned in Cholangiogram. Note (a) duodenoscope positioned in duodenum with tip at distal aspect of common bile duct and (b) moderately dilated bile duct.
This video, captured via endoscopic retrograde cholangiopancreatography, shows cannulation of common bile duct (CBD). Dye is then injected, and CBD is seen on fluoroscopy; there are filling defects suggestive of stones within duct. Video courtesy of Dawn Sears, MD, and Dan C Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.

Fluoroscopic imaging is also typically performed after intervention to assess the adequacy of the treatment (eg, to look for residual filling defects in a bile duct after stone extraction).

Therapeutic Interventions for Stones, Stenoses, Strictures, Leaks, and Tissue Sampling

Most patients who present for ERCP have previously undergone noninvasive diagnostic testing (eg, computed tomography [CT], magnetic resonance cholangiopancreatography [MRCP], or ultrasonography [US]) that revealed an abnormality potentially amenable to intervention via ERCP. Thus, cholangiography, pancreatography, or both are performed to confirm or to better characterize a potential lesion and are followed by an intervention if treatment is indicated.

Although a multitude of therapeutic ERCP maneuvers are known, the most common are those dealing with biliary or pancreatic duct stones, malignant or benign strictures or stenoses (see the image below), leaks, and tissue sampling.

Biliary obstruction secondary to chronic pancreati Biliary obstruction secondary to chronic pancreatitis. Used with permission from the Johns Hopkins Division of Gastroenterology and Hepatology (www.hopkinsmedicine.org/gi). Illustration Copyright© 1998-2003 by The Johns Hopkins Health System Corporation and The Johns Hopkins University. Illustration created by Mike Linkinhoker.

For example, to manage choledocholithiasis, a biliary sphincterotomy (see the video below) is generally performed initially to facilitate passage of the stone through the distal bile duct.

This video, captured via endoscopic retrograde cholangiopancreatography, shows sphincterotomy being performed. Sphincter of Oddi is being cut by using electrocautery applied to biliary cannulation catheter. Video courtesy of Dawn Sears, MD, and Dan C Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.

Once this is done, devices such as a stone extraction balloon or a stone basket (with or without stone crushing capacity) can be passed over the guide wire in the bile duct to help deliver the stone. (See the image below.) If this approach is unsuccessful, more advanced accessories (eg, pneumatic balloon dilation of the biliary sphincter or electrohydraulic/laser lithotripsy devices) can be used.

Technique for pancreatic stone extraction. Used wi Technique for pancreatic stone extraction. Used with permission from the Johns Hopkins Division of Gastroenterology and Hepatology (www.hopkinsmedicine.org/gi). Illustration Copyright© 1998-2003 by The Johns Hopkins Health System Corporation and The Johns Hopkins University. Illustration created by Mike Linkinhoker.

Indications for biliary endoscopic sphincterotomy include the following[16] :

  • CBD stones
  • Facilitation of biliary stent placement (especially multiple stents) for malignant or benign CBD obstruction
  • Palliation of obstruction due to malignant ampullary neoplasm as an alternative to stent placement in selected cases
  • Sphincter of Oddi dysfunction (SOD) or benign papillary stenosis
  • Biliary leaks
  • Miscellaneous conditions (choledochocele, sump syndrome, biliary parasites)

A large, prospective study of complications related to biliary sphincterotomy found that the rate of complications was highest when the indication for the procedure was suspected SOD (21.7%) and lowest when the indication was removal of CBD stones after laparoscopic cholecystectomy (4.9%). Pancreatitis developed in 19% of patients with suspected SOD, as compared with 3.6% of patients with other indications for sphincterotomy.[30, 49, 50]

Precut sphincterotomy, a combined endoscopic-percutaneous procedure, difficult biliary cannulation, and the presence of cirrhosis were all found on multivariate analysis to be significant risk factors for complications of biliary sphincterotomy, though to a much lesser degree than suspected SOD. Severe complications occurred nearly three times more often with suspected SOD (3.7%) than with other indications (1.3%).[30, 49, 50]

Another common intervention involves placing a biliary stent into the bile duct to treat a biliary obstruction secondary to benign or malignant biliary stricture (see the images and video below). Multiple stents are available, varying in design, material, and size; the choice of an appropriate stent depends on the clinical situation.

Fluoroscopic image of plastic stent in bile duct. Fluoroscopic image of plastic stent in bile duct. Also note guide wire adjacent to stent in bile duct.
This video, captured via endoscopic retrograde cholangiopancreatography, shows placement of biliary stent into common bile duct. Video courtesy of Dawn Sears, MD, and Dan C Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.
(A) Biliary sphincterotomy and stent placement; (B (A) Biliary sphincterotomy and stent placement; (B) corresponding endoscopic retrograde cholangiopancreatography (ERCP) film. Used with permission from the Johns Hopkins Division of Gastroenterology and Hepatology (www.hopkinsmedicine.org/gi). Illustration Copyright© 1998-2003 by The Johns Hopkins Health System Corporation and The Johns Hopkins University. Illustration created by Mike Linkinhoker.

Complications

ERCP is an advanced endoscopic technique that carries a higher risk of procedure-related complications than other endoscopic procedures do.[51, 52]  Besides the risks associated with most other endoscopic procedures (eg, mucosal perforation related to traumatic passage of the endoscope, cardiopulmonary events, adverse IV medication reactions, hemorrhage, infection, or oxygen desaturation), ERCP also carries a risk for the following specific complications[1] :

  • Post-ERCP pancreatitis (PEP) - Prophylactic measures include rectal nonsteroidal anti-inflammatory drugs (NSAIDs), pancreatic duct stents, and intensive intravenous hydration [53]
  • Postsphincterotomy bleeding
  • Infection (cholangitis, bacteremia)
  • Retroperitoneal perforation

Recurrence of choledocholithiasis after therapeutic ERCP is a possibility. In a retrospective case-control study by Deng et al, independent risk factors for the development of recurrent choledocholithiasis after ERCP included the following[54] :

  • General characteristics - Age greater than 65 years
  • Medical history - Previous choledocholithotomy
  • ERCP-related factors - Endoscopic papillary balloon dilation (EPBD); endoscopic sphincterotomy (EST); CBD stent implantation; multiple (≥2) ERCP procedures
  • CBD-related factors - Stones in the intrahepatic bile duct; periampullary diverticula; choledocholithiasis 10 mm or greater in diameter; bile duct–duodenal fistula; biliary tract infection
  • Treatment-related factors - No preoperative antibiotic use

Zhang et al retrospectively studied the application of enhanced recovery after surgery (ERAS) methods to perioperative nursing in 161 patients (ERAS group, n = 78; control group, n = 83) who underwent ERCP for treatment of biliary calculus.[55]  Time to first ambulation, exhausting time, time to defecation and eating, and nasobiliary drainage time were significantly shorter in the ERAS group. The incidence of postoperative complications was also significantly lower in the ERAS group (9.1% vs 20.4%), as were nasobiliary drainage time (26.53 ± 7.43 vs 37.56 ± 9.91 hours), duration of hospitalization (8.32 ± 1.55 vs 4.56 ± 1.38 days), and hospitalization expenses.