Endoscopic Retrograde Cholangiopancreatography (ERCP) Technique

Updated: May 19, 2017
  • Author: Ahmad Malas, MD; Chief Editor: Kurt E Roberts, MD  more...
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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.

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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 The scope is then carefully withdrawn with slight clockwise torque applied to bring the endoscope into the "short position." 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-colored 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. [42, 43]

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. [44]  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).

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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, leaks, and tissue sampling.

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. If this approach is unsuccessful, more advanced accessories (eg, pneumatic balloon dilation of the biliary sphincter or electrohydraulic/laser lithotripsy devices) can be used.

Indications for biliary endoscopic sphincterotomy include the following [14] :

  • 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. [27, 45, 46]

Precut sphincterotomy, a combined endoscopic-percutaneous procedure, difficult biliary cannulation, and a patient with cirrhosis were all found on multivariate analysis to be significant risk factors for complications of biliary sphincterotomy, although to a much lesser degree than suspected SOD. Severe complications occurred more than three times as often with suspected SOD (3.7%) than with other indications (1.3%). [27, 45, 46]

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.
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Complications

ERCP is an advanced endoscopic technique that carries a higher risk of procedure-related complications than other endoscopic procedures do. [47, 48]  Besides the risks associated with most other endoscopic procedures (eg, mucosal perforation related to traumatic passage of the endoscope, cardiopulmonary events, adverse intravenous medication reactions, hemorrhage, infection, or oxygen desaturation), ERCP also carries a risk for the following specific complications:

  • PEP
  • Postsphincterotomy bleeding
  • Infection (cholangitis, bacteremia)
  • Retroperitoneal perforation
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