Endoscopic retrograde cholangiopancreatography

Watch a video presentation of this article

Answer questions and earn CME

Abbreviations

ASGE

The American Society for Gastrointestinal Endoscopy

ERCP

endoscopic retrograde cholangiopancreatography

EUS

endoscopic ultrasound

PEP

post‐ERCP pancreatitis

PSC

primary sclerosing cholangitis

SOD

sphincter of Oddi dysfunction

Introduction

Since its introduction in 1968, endoscopic retrograde cholangiopancreatography (ERCP) has revolutionized the diagnosis and management of pancreatobiliary disease. During most of the intervening years, ERCP has been invaluable as both a diagnostic and therapeutic procedure. However, advances in noninvasive radiographic and less invasive endoscopic imaging have transformed ERCP into an almost exclusively therapeutic procedure.

Procedure

ERCP involves the passage of a side‐viewing duodenoscope transorally to the second portion of the duodenum. Various catheters, which directly exit the working channel of the duodenoscope, may be used for cannulation of the common bile duct and/or pancreatic duct. Contrast injection and real‐time fluoroscopy allows the endoscopist to image ductal structures (see Figure 1). A guidewire is commonly used as a monorail to maintain position within the duct and to facilitate the passage and proper placement of catheters and stents. Various diagnostic and therapeutic procedures can be performed and are briefly outlined below.

Figure 1.

Normal cholangiogram.

Sphincterotomy refers to an incision made with electrocautery through the sphincter of Oddi, a fibromuscular sheath encapsulating the distal common bile duct, pancreatic duct, and shared common channel. Retrieval balloons can be inflated within the duct and then withdrawn to remove stones and sludge. Wire baskets may also be used to grasp and/or crush stones within the duct to facilitate removal. Ductal or ampullary strictures can be dilated with a hydrostatic balloon or a graduated catheter passed over a guidewire. Stents composed of plastic or metal can ameliorate obstruction caused by benign and malignant biliary strictures; they also have a role in the management of postoperative biliary leaks and in reducing the risk of post‐ERCP pancreatitis. Strictures can be sampled with forceps biopsy and brush cytology when cancer is suspected. Direct endoscopic visualization of the duct is also possible and is useful in diagnosing indeterminate strictures and in managing large or otherwise difficult stones.

Indications

ERCP is indicated for the evaluation and management of various pancreatobiliary disease states (see Table 1). In addition to the indications below, it is used to protect the bile duct and pancreatic duct during resection of ampullary polyps (ampullectomy). See Table 2 for several situations in which the performance of ERCP may not be indicated.

Table 1.

Indications for ERCP

Ampullectomy for Ampullary Polyp
Biliary
Choledocholithiasis
Bile leak
Biliary stricture
Malignant
Pancreatic cancer
Cholangiocarcinoma
Ampullary adenocarcinoma
Benign
Primary sclerosing cholangitis
Posttransplant stricture
Chronic pancreatitis
Sphincter of Oddi dysfunction
Pancreatic
Recurrent acute pancreatitis
Chronic pancreatitis
Pancreatic duct leak
Sphincter of Oddi dysfunction

Table 2.

Scenarios Where ERCP Is Not Definitely Indicated

• Acute pancreatitis in the absence of cholangitis or ongoing biliary obstruction.

• A single episode of idiopathic pancreatitis.

• Acute cholecystitis in the absence of biliary obstruction.

• Malignant jaundice without cholangitis prior to surgery (without planned neoadjuvant therapy).

• Suspected pancreatobiliary abdominal pain in the absence of elevated liver/pancreatic enzymes and/or a dilated duct (type III sphincter of Oddi dysfunction).

• For duct clearance prior to cholecystectomy in the absence of a documented stone or high clinical suspicion for a bile duct stone (alternative imaging such as EUS or magnetic resonance cholangiopancreatography is recommended in this context).

Biliary

Biliary indications for ERCP include choledocholithiasis, malignant or benign strictures, and bile leaks.

Gallstone Disease

The most common etiology of biliary obstruction is choledocholithiasis,1 and sphincterotomy with stone extraction is successful in > 90% of cases2 (see Figure 2). After sphincterotomy, stones may be removed from the duct with a balloon and/or wire basket. If the stone is too large to exit the duct, it may be crushed with a mechanical lithotripsy basket or via cholangioscopy and intraductal lithotripsy (commonly with electrohydraulic or laser lithotripsy). Alternatively, the biliary orifice may be dilated to a large enough diameter to facilitate stone removal.

Figure 2.

Biliary stricture secondary to chronic pancreatitis.

Transpapillary gallbladder access and stenting can be achieved with ERCP. In patients with symptomatic cholelithiasis or cholecystitis who are poor surgical candidates (i.e., advanced cirrhosis, multiple medical comorbidities), this strategy can potentially obviate the need for cholecystostomy tube placement.

Benign Strictures

Benign biliary strictures are generally managed with dilation and stent placement. Benign strictures may be due to compression from chronic pancreatitis, primary sclerosing cholangitis (PSC), or postoperatively (e.g., postliver transplant anastomotic stricture or cholecystectomy‐related injury). Whereas success rates for the treatment of biliary strictures secondary to chronic pancreatitis were initially discouraging,3 the use of multiple stents and more frequent endoscopic sessions has led to improved and more durable outcomes4 (see Figure 3). Dominant strictures associated with PSC may be more optimally managed with balloon dilation as opposed to stent placement because limited data seems to suggest an increased risk of cholangitis with stent placement.5 Biliary anastomotic strictures following liver transplantation can lead to a considerable amount of morbidity. The overall success rates for therapy of anastomotic strictures with balloon dilation with or without plastic stent placement are excellent, although repeated sessions may be required due to stricture recurrence.6 Fully covered metal stents have increasingly been used for benign strictures recalcitrant to traditional endotherapy.

Figure 3.

Cholangiogram showing multiple stones in a dilated main bile duct.

Malignant Strictures

ERCP and biliary stenting are indicated for the relief of jaundice secondary to pancreatic cancer. The diagnostic yield of stricture brush cytology, however, is low (30%‐50%), albeit somewhat higher when combined with forceps biopsy (65%‐70%).7 Endoscopic ultrasound (EUS)‐guided fine needle aspiration, where available, has largely supplanted ERCP for this indication because it has a higher sensitivity (75%‐94% in multiple studies). The sensitivity of brushings/biopsies for the diagnosis of cholangiocarcinoma has also been disappointing, ranging from 18% to 60%.8 Cholangioscopy‐guided biopsies may increase diagnostic yield of sampling indeterminate strictures, with recent studies suggesting an improvement in sensitivity (76.5% versus 29.4%) and negative predictive value (69.2% versus 42.8%), respectively, as compared to traditional techniques.9 Newer diagnostic tests, including the use of digital imaging analysis and fluorescence in situ hybridization, may also offer increased sensitivity but are not yet widely available.10

Bile Leaks

ERCP with stent placement for the management of postoperative biliary leaks leads to endoscopic closure in 80% to 100% of patients.11 Sphincterotomy is not absolutely required for the treatment of bile leaks when stenting.

Sphincter of Oddi Dysfunction

The role of ERCP and sphincterotomy with or without manometry in patients with suspected sphincter of Oddi dysfunction (SOD) continues to evolve. The complications related to ERCP and sphincterotomy, particularly pancreatitis, are higher than for other indications. More than 90% of patients with type 1 SOD (biliary pain with elevated liver chemistries and a dilated bile duct) experience relief of pain with biliary sphincterotomy; manometry is not necessary in this setting.12 Patients with type 2 SOD (biliary pain with either elevated liver enzymes or a dilated bile duct) also respond to sphincterotomy, albeit at a lower rate (39%‐66%).12 The decision to use sphincter of Oddi manometry to guide the decision regarding sphincterotomy in patients with suspected type 2 SOD remains controversial.12 A recent multicenter randomized controlled trial demonstrated a lack of significant pain improvement with biliary sphincterotomy in patients with type 3 SOD.13

Pancreatic

ERCP has a limited role in the diagnostic evaluation of recurrent acute pancreatitis because noninvasive methods are generally preferred (at least initially). Most causes of recurrent acute pancreatitis (including medications, hypertriglyceridemia, hypercalcemia, biliary sludge/stone, chronic pancreatitis, pancreatic masses or cysts, ampullary lesions, and pancreas divisum) may be diagnosed with a good history, laboratory testing, cross‐sectional imaging, transabdominal ultrasound, and/or endoscopic ultrasound. ERCP and sphincter of Oddi manometry is typically reserved for the subset of patients with idiopathic recurrent acute pancreatitis without a cause identified with this rigorous evaluation and testing.

Pancreas divisum as a cause for recurrent acute pancreatitis remains controversial because the congenital anomaly is commonly present (approximately 7% incidence) in normal subjects,14 and only a small proportion of those with divisum develop pancreatitis. However, in patients without another etiology for recurrent pancreatitis, some studies have demonstrated a trend toward better outcomes following endoscopic therapy (including minor papillotomy and possible stent placement).15

Pancreatic duct endotherapy of symptomatic stones, strictures, or pseudocysts can ameliorate pain associated with chronic pancreatitis, although studies are mixed as to the rate and durability of pain relief. Stones and strictures are treated in a similar manner as in the bile duct, with pancreatic sphincterotomy, balloon or basket stone extraction, mechanical or pancreatoscopy‐guided lithotripsy, balloon or catheter dilation, and stenting (see Figure 4). Pancreatic duct leaks leading to pancreatic ascites or pseudocyst formation are managed with transpapillary stenting. Although not required in every case, stents that cross (or “bridge”) the disrupted ductal segment may lead to better outcomes.16 Transpapillary drainage of pancreatic fluid collections can be accomplished when the collection communicates with the pancreatic duct.

Figure 4.

Pancreatogram demonstrating chronic pancreatitis, with a dilated and irregular main pancreatic duct, prominent side branches, and intraductal stones.

Complications of ERCP

Pancreatitis is the most common serious complication of ERCP (see Table 3). Although an asymptomatic increase in pancreatic enzymes can occur in up to 75% of patients following ERCP, a consensus definition for post‐ERCP pancreatitis (PEP) has been widely adopted and takes into account such factors as new or worsened abdominal pain, the need for hospitalization or extension of current hospitalization, and significantly elevated pancreatic enzymes > 24 hours after the procedure. Using these more stringent criteria, the actual incidence of post‐ERCP pancreatitis ranges from 1.6% to 15.7%.17

Table 3.

Risk Factors for the Development of Post‐ERCP Pancreatitis

Balloon dilation of biliary sphincter
History of post‐ERCP pancreatitis
Normal bilirubin
Pancreatic duct injection
Pancreatic sphincterotomy
Precut sphincterotomy
Suspected sphincter of Oddi dysfunction
Young age

Modified from Freeman.27

Table 4.

Understanding ERCP

Patient Guide: What to Expect During Endoscopic Retrograde Cholangiopancreatography (ERCP)
Why is this test done?	‐ This test allows the doctor to evaluate your bile duct and pancreatic duct by obtaining high‐quality x‐ray images ‐ Blockages can be treated with a combination of sphincterotomy (incision into the bile duct opening), dilation, and stent placement ‐ Abnormal strictures can be sampled with forceps and brush devices to rule out cancer ‐ A stent (plastic or metal tube) can be inserted into the bile duct if a narrowing is noted, to allow for adequate bile flow
How should I prepare for my procedure?	‐ Do not eat or drink after midnight on the night before your procedure. ‐ Tell your doctor about your complete medical history, including medications, allergies, and any indwelling cardiac devices ‐ Some of your medications may require adjustment prior to scheduling, particularly if you take any blood thinners ‐ You will need to arrange for a friend or family member to drive you home from the procedure, as you cannot operate heavy machinery after undergoing sedation
What do I do during the procedure?	‐ Vital signs will be taken and an intravenous catheter placed for medication administration. ‐ You will receive moderate to deep sedation prior to the scope being advanced ‐ Depending on the center at which you are undergoing your procedure, you may be placed on your back, your side, or your stomach ‐ After sedation, the scope will be passed through your mouth, down your esophagus and into the stomach and beginning of your small intestine. ‐ The procedure length is variable, though an ERCP typically lasts 30‐60 minutes.
What happens after the procedure?	‐ You will be monitored while the medications wear off; you may feel drowsy during this time period ‐ You may notice a sore throat and bloating after the procedure. This is not uncommon and will get better. ‐ Call your doctor immediately if you experience any complications (see below).
Are there risks involved?	‐ Complications are rare but can occur. These include: ‐ Inflammation of your pancreas known as pancreatitis. Endoscopists use a variety of maneuvers to reduce this risk. ‐ Bleeding ‐ Infection ‐ Heart or lung trouble ‐ A tear in the lining of the digestive tract, which can require emergency surgery
When should I contact my doctor?	‐ Call if you have any concerns, or should you experience any of the following: ‐ Fever of 100.4 F or higher ‐ Trouble swallowing ‐ Difficulty breathing ‐ Blood in vomit or stool ‐ Increasing throat, chest or abdominal pain

Recent mounting evidence has revealed several maneuvers that may reduce the risk of PEP, including placement of a prophylactic pancreatic duct stent18 and administration of rectal indomethacin.19 Vigorous periprocedural hydration with lactated ringer's solution has shown promise in a pilot study, although larger studies are required to confirm these data.20 Because rectal indomethacin can adversely affect renal function, and aggressive IVF can worsen fluid overload, these strategies should be utilized with caution in cirrhotic patients.

Post‐ERCP hemorrhage is typically secondary to sphincterotomy and complicates up to 1.3% of cases.21 However, the incidence of severe hemorrhage is less than 1/1000.22 Because ERCP with sphincterotomy is deemed a higher risk procedure for bleeding, antiplatelet/anticoagulant therapy should be adjusted as recommended by The American Society for Gastrointestinal Endoscopy (ASGE) guidelines.23

The incidence of perforation during ERCP ranges from 0.1% to 0.6%24 and is broadly classified as guidewire‐induced periampullary perforation during sphincterotomy and luminal perforation at a distinct site. Prompt recognition and management with endoscopic therapy (if possible), antibiotics, and early collaboration with surgeons can help mitigate related morbidity.

Infectious complications occur in less than 1% of patients.25 ASGE guidelines recommend consideration of prophylactic antibiotics in the following situations: achievement of complete biliary drainage is unlikely (e.g., primary sclerosing cholangitis, hilar mass), posttransplant strictures, anticipated transmural or transpapillary pseudocyst drainage, and immunocompromised patients.26, 27

Conclusion

Over approximately 50 years, ERCP has largely evolved into a therapeutic procedure and is indicated for a variety of pancreatobiliary disease states.