Basics of ERCP
Larissa Fujii-Lau, MD
Since endoscopic retrograde cholangiopancreatography (ERCP) was first introduced in 1968 and endoscopic sphincterotomy in 1974, it has become the standard of care in the therapeutic management of many pancreaticobiliary diseases.1,2 ERCP remains one of the most technically challenging of all procedures performed by gastroenterologists and typically requires an additional year of training to become comfortable with its nuances. This chapter reviews the basics of ERCP through the periprocedural period but does not focus on the interventional aspect of this procedure as that is covered in later chapters.
PREPROCEDURAL CONSIDERATIONS
Indications
ERCP has evolved from a diagnostic procedure to a predominately therapeutic intervention. Cross-sectional imaging with abdominal ultrasound (US), computed tomography (CT) scan, and/or magnetic resonance cholangiopancreatography (MRCP) as well as endoscopic ultrasound (EUS) or intraoperative cholangiogram (IOC) is often used to decide which patient requires therapeutic ERCP. It is important to review all of these images prior to the case to assist in procedural planning. Table 25.1 lists the indications of ERCP.
Contraindications
Risks of procedure are thought to outweigh benefits.
Lack of consent.
Suspected luminal perforation.
Lack of necessary equipment/accessories needed to complete the procedure.
If a sphincterotomy is being planned, then patients with coagulopathies and/or taking antithrombotic medications.3
TABLE 25.1 Indications for ERCP
Biliary Indications
Pancreatic Indications
Other
Choledocholithiasis
Biliary stricture
Bile leak
Obstructive jaundice
Cholangitis
Biliary pancreatitis
Papillary stenosis (type 1 SOD)
Choledochocele (type III choledochal cyst) treatment
Pancreatic duct stones
Pancreatic duct stricture
Pancreatic duct leak
Pseudocyst drainage
Ampullectomy for adenoma
SOD, sphincter of Oddi dysfunction.
Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) may be continued perioperatively.
If a patient is coagulopathic and requires urgent ERCP, then alternatives such as balloon sphincteroplasty or stent placement without preceding sphincterotomy can be considered.
Periprocedural Administration of Antibiotics
Routine use of periprocedural administration of antibiotics (typically a fluoroquinolone, beta-lactam, or third-generation cephalosporin) does not decrease the risk of infectious complications.4,5
Judicious use of antibiotics in certain situations does have benefit in certain patients:
Complex strictures where there is a risk of retained contrast (i.e., hilar strictures, primary sclerosing cholangitis).
Immunosuppressed patients.
Contrast is injected during failed cannulation attempts.
Equipment
Side-viewing duodenoscope (Fig. 25.1)
Up/down and left/right dials, elevator that allows for upward/downward movement
Typically 11.5 mm in diameter and has a large diameter working channel (typically 4.2 and 4.8 mm) allowing for 10 French (Fr) equipment
Sphincterotome (Fig. 25.2)
Advantage of being capable of performing a sphincterotomy, has the capability to bow/flex, and studies have shown improved cannulation rates compared to standard cannulas.6,7
Teflon catheter that contains a continuous wire loop with 2 to 3 cm of exposed wire to allow for sphincterotomy.
FIG. 25.1 Side-viewing duodenoscope. Notice how the camera is proximal to the tip of the duodenoscope. It is important to keep this in mind as pushing the duodenoscope under resistance can lead to perforation caused by the tip of the scope.
FIG. 25.2 Sphincterotome with a slight bow/flex of the wire.
Electrocautery unit for sphincterotomy.
Cannulas
Can be helpful in some situations such as the tapered tip cannula for dilation of tight strictures to allow for passage of larger accessories or the needle-tip catheter for cannulation of the minor papilla (Cramer cannula, Cook Medical, Bloomington, IN).
Guidewires
Important for cannulation and maintaining access in the desired duct and facilitate placing and exchange of any accessory.
Vary in diameters (ranging from 0.018 to 0.035 inch), length (ranging from 260 to 480 cm), coating (i.e., Teflon), tip material (i.e., hydrophilic, platinum, tungsten), and tip shape (straight or angled).
Guidewires that are more hydrophilic, maneuverable, and flexible are used for cannulation and to pass through tight strictures.
Stiffer guidewires are useful to assist with advancement of any accessory.
Locking device if the short-wire system is preferred.
Examples: Rapid Exchange Biliary System (Boston Scientific), Fusion system (Cook Medical), or V-system (Olympus)
Fluoroscopy is required in majority of ERCPs.
Full strength contrast theoretically decreases the amount of contrast required to delineate the anatomy, particularly during cannulation to limit inadvertent pancreatic duct injection.
Diluted contrast to half strength decreases the risk of obscuring small stones during contrast injection.
INTRAPROCEDURAL CONSIDERATIONS
Sedation
Each institution differs in regard to preference for the type of sedation administered during an ERCP. Most institutions use an anesthesiologist or nurse anesthetist to provide sedation for ERCP cases, but some also provide nurse-administered sedation under the guidance of the endoscopist.
It is important to take into account the patient’s inherent risk of sedation based on cardiopulmonary status, physical examination (including the body measurement index [BMI] and Mallampati score), and presence of cervical spine disease when determining the level of sedation. In addition, the anticipated length and complexity of the planned procedure should
be considered when deciding how to sedate the patient. If the indication is for stent removal, a lower level of sedation may be required than for an ERCP planned in a patient with a hilar stricture. Furthermore, patient positioning may dictate the type of sedation given. In the prone position, airway patency and assessment of respirations are more difficult than in the left lateral or supine position. Therefore, general anesthesia is often preferred, but not required, if the patient is prone.
be considered when deciding how to sedate the patient. If the indication is for stent removal, a lower level of sedation may be required than for an ERCP planned in a patient with a hilar stricture. Furthermore, patient positioning may dictate the type of sedation given. In the prone position, airway patency and assessment of respirations are more difficult than in the left lateral or supine position. Therefore, general anesthesia is often preferred, but not required, if the patient is prone.
Patient Positioning
Typically patients are positioned either left lateral or prone during ERCP. Patient positioning is determined by endoscopist preference, anesthesiologist concerns (airway, respiratory stability), and patient factors (BMI, neck flexibility, abdominal wounds, abdominal distention). The prone position typically allows for better fluoroscopic imaging of the distal bile and pancreatic duct systems (easier to determine what duct is being cannulated) and the intrahepatic system. In addition, secretions tend to obscure duodenoscope visualization less in the prone position. Despite these theoretical advantages, studies have not shown a significant difference in technical success or adverse events between the two positions.8,9,10
Technique
Duodenoscope Insertion
Duodenoscope insertion is often the first step to learn during ERCP training. As compared to the standard gastroscope, the duodenoscope is side-viewing and has stiffer tip. With this side view, to gain passage through any opening (i.e., upper esophagus, lower esophagus, pylorus), the orifice needs to be positioned below the view of the scope. If the endoscopist can see the opening, the scope is not positioned correctly and will not advance through it. It is important not to push with significant force while advancing the duodenoscope to decrease the risk of perforation.
Tips to advance the duodenoscope to the papilla:
When inserting into the mouth, slightly reflect the up/down knob downward toward you in a counterclockwise fashion (tip up) until you pass the tongue.
Then reflect the up/down knob upward away from you in a clockwise fashion (tip down) to advance the scope to the back of the throat.
Use your right hand to make small right/left motions of the scope while gently advancing the duodenoscope to pass the cricopharyngeus and enter into the esophagus.
Passing through the esophagus should be relatively straightforward, continuing with the small right/let torquing movements of the duodenoscope shaft using your right hand while advancing the duodenoscope.
In the esophagus, be cautious in older patients or those with esophageal disorders who may have a tortuous esophagus.
At the lower esophageal sphincter, make sure you do not see the opening of the gastroesophageal junction in direct view. If you see the gastroesophageal opening in view, then reflect the up/down knob downward toward you in the counterclockwise direction (tip up) to put the opening at the 6-o’clock position, then gently advance the duodenoscope into the stomach.
In the stomach, similar to an upper endoscopy, torque the duodenoscope shaft to the right (clockwise) using your right hand while advancing the duodenoscope.
When you reach the antrum, reflect the up/down knob downward toward you in the counterclockwise direction (tip up) until you reach the pylorus.
Often when advancing the duodenoscope in the antrum, the pylorus can often be seen en face. Position the pylorus so it is lying in the 6-o’clock position below the duodenoscope and your view of the pyloric opening is lower and lower (similar to a “setting sun”) by reflecting the up/down knob downward toward you (tip up).
Once the duodenoscope enters the posterior duodenal bulb, rotate the duodenoscope shaft toward the right (clockwise), turn your body a little to the right, continue to hold the up/down knob a little downwards toward you (tip up) until you reach the descending duodenum
Shorten the scope by keeping the right torque of the duodenoscope shaft (some endoscopists lock it in this position), right torque of your body, then pull the duodenoscope back to allow it to naturally advance to the second/third portion of the duodenum. Continue to pull back on the scope until you see the papilla.
On fluoroscopy, the duodenoscope should look like a curved L in the short position, which is preferred in majority of cannulations (Fig. 25.3). Sometimes the long position is required for appropriate alignment of the papilla (Fig. 25.4). To move the scope into the long position, push the scope in with a right torque. Using fluoroscopy often helps to ensure that the scope is moving appropriately and it is important not to push against too much resistance as this is a technique that can rarely lead to a perforation.Related posts:
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