Assembling the Team

We recommend that ERCP be done independently only by physicians with prior formal training in ERCP. An adequate number of examinations during training varies greatly with the trainee but should include at least 200 examinations.¹⁷ This number includes at least 100 therapeutic examinations. Successful biliary cannulation rates should be at least 85% and preferably 90%. We recommend that nurses have experience with at least 1000 upper GI and colonoscopy examinations before “graduating up” to the ERCP suite. Nurses should train alongside experienced ERCP nurses for 100 to 200 examinations before independent guidewire and accessory management is undertaken. Two nurses are needed per examination: one for sedation and analgesia administration and one for accessories management. Radiology technicians working in ERCP should maintain longevity and be team members rather than rotate frequently. In nearly all centers, a radiologist no longer assists in fluoroscopy or image acquisition except in the most difficult cases. Collaborative reading of final images may aid in the accuracy of final interpretation. Final reading by general radiologists with little pancreatobiliary training, experience, or interest may be counterproductive.

Patient Preparation

Patient preparation includes an updated medical history and physical examination; recent complete blood cell count, serum liver chemistries, serum amylase, and lipase; and at least one noninvasive imaging study of the upper abdomen with abdominal ultrasound, CT scan, or magnetic resonance cholangiography. Platelet count, prothrombin time, and partial thromboplastin time may be obtained if therapeutics are anticipated. However, a history of liver disease, renal disease, and bleeding are adequate to detect most patients with increased bleeding risk. Patients with a history of easy bruising, excessive bleeding after dental extraction, other postoperative bleeding, or family history of coagulopathy are best evaluated with the help of hematology consultation.

Risk factors such as anticoagulant therapy, prosthetic heart valves, and allergies must be addressed.¹⁸ Patients with iodine allergy are at very low risk of allergic reaction¹⁹; nevertheless, some centers continue to use prednisone, 30 to 40 mg orally, 15 hours and 3 hours before the examination. Diphenhydramine (Benadryl), 25 mg intravenously, may be added if serious past reactions have occurred. Iodine allergy is not a reason to omit a needed examination, but limiting the volume of contrast medium used is logical. Air²⁰ can be successfully used for cholangiography if needed. If possible, aspirin and nonsteroidal antiinflammatory drugs should be avoided for 7 days before the procedure.

Fasting for 8 hours is generally recommended except for taking oral medications, such as blood pressure medication, the morning of the examination. Patients undergoing examination in the afternoon may have a clear liquid breakfast. Patients taking narcotics may need to fast for 12 to 16 hours or consume only clear liquids the evening before. Patients with constipation and patients who have had recent oral contrast agents may benefit from an oral laxative purge to clear the transverse colon of material, which may otherwise overlay and obscure viewing of the gallbladder, terminal bile duct, and pancreas. Broad-spectrum antibiotics are recommended (e.g., ciprofloxacin) for patients with obstructive jaundice, cholangitis, pseudocysts, fistulas, or immunosuppressed state. Quinolones are an attractive choice because they can be given orally. Oral simethicone solution is recommended 30 to 60 minutes before examination start time to decrease intraluminal foam, which may obscure visualization.

Informed Consent

Informed consent for ERCP must be obtained. It is both legally and ethically necessary to apprise the patient (and family members if applicable) of the risks, benefits, and alternatives of the anticipated procedure. Table 37.1 lists potential complications of diagnostic and therapeutic ERCP and their relative frequency. Although legal standards continue to evolve, we recommend that patients be informed of the potential complications and the relative frequencies of complications. In addition, we recommend that patients be told that a severe complication possibly may result in a prolonged hospital stay, intensive care unit monitoring, or open surgery and very rarely may result in permanent disability or death. Complication rates vary according to patient and procedure risk factors and the disease process being evaluated and treated. Patients with uncomplicated biliary stones, malignancy, or chronic pancreatitis have lower complication rates, whereas patients with acute recurrent pancreatitis and suspected sphincter of Oddi dysfunction have twofold to fourfold higher complication rates. Procedure techniques associated with higher complication rates include repeated cannulation attempts, repeated pancreatic duct injections, pancreatic parenchymal acinarization, and precut sphincterotomy (without associated protective pancreatic stent). Attention to details of the technique and patient selection can minimize, but not eliminate, complications. Morbidity can be limited by early recognition and treatment of complications.

Endoscopic Equipment

ERC can be performed with fiberoptic or video chip, side-viewing instruments. Endoscopes are 120-cm working length and generally categorized as diagnostic (approximately 10-mm diameter) or therapeutic (12- to 13-mm diameter). Video systems offer the advantage of television monitor viewing by all persons in the endoscopy suite; this offers better teaching capabilities and allows better coordination between the endoscopist and nursing assistants. Some newer generation endoscopes combine a large working channel diameter up to 4 mm with a standard 10- to 11-mm outer diameter (Fig. 37.1). A newer generation pediatric videoendoscope with outer diameter less than 7 mm is now available from Olympus America Inc. Most ERCP examinations are done with air insufflation. Limited data show that carbon dioxide inflation reduces postprocedure abdominal distention.²¹ For patients undergoing Billroth II procedures, we generally start with a standard side-viewing duodenoscope, but an end-viewing endoscope is occasionally needed. In patients with a long Roux-en-Y gastroenterostomy or choledochojejunostomy, a 160-cm pediatric colonoscope or a 220-cm enteroscope can reach the bile duct in greater than half of patients.²² Double-balloon enteroscopy has facilitated Roux-en-Y limb traversal.^23,24 The lack of a catheter-deflecting elevator and limited compatibility accessories make end-viewing endoscopy difficult in these settings. Rendezvous with transhepatic wire passage is occasionally helpful (Fig. 37.2).

Fig. 37.1 A, Photograph of two side-viewing endoscopes used for standard endoscopic retrograde cholangiography (ERC). Biopsy channels range from 3.2 to 4.5 mm to accommodate a wide variety of accessories needed in diagnostic and therapeutic biliary studies. B, Newer generation Olympus pediatric videoduodenoscope for use in children weighing less than 10 kg.

Fig. 37.2 A patient underwent gastric bypass surgery for obesity and developed biliary colic and suspected common duct stones. A pediatric colonoscope was passed by mouth but failed to pass retrograde back to the descending duodenum. A guidewire was passed percutaneous transhepatically into the duodenum, beyond the ligament of Treitz (arrow), and on down into the jejunum. The wire was grasped, and the endoscope was pulled back to the papilla for stone therapy.

Current-generation endoscopes are capable of undergoing submersion disinfection. After cleaning, endoscopes should be hung in vertical position to facilitate drying. In the past, Pseudomonas infections were directly linked to inadequate ERCP scope disinfection. Ideally, endoscopes should be cultured periodically. Patients developing infections after undergoing ERCP should be cultured for the presence of Pseudomonas species (see Chapter 4).

Radiology Suite

Few endoscopists have a dedicated suite for ERCP. We are aware of no manufacturer who markets a fluoroscopy unit specifically for ERCP. Most endoscopists schedule time in the radiology department and use general purpose or angiographic units. Film documentation is likely to disappear in the next decade, with digital formats viewed only on high-resolution monitors, which are becoming the new standard. Quality digital images now rival film quality. Flat tables with fixed overhead carriage have limited versatility. The preferred x-ray table includes the capability to tilt the patient’s head up and down 30 degrees and has C-arm carriage, which allows axial, cranial, caudal, vertical, and horizontal movements, allowing viewing at multiple angles (Fig. 37.3). Because the patient is usually positioned prone with the head at the “foot” of the table, ability to reverse the viewing image in both the vertical and the horizontal axes is helpful. In the past, endoscopists used older generation x-ray units, including portable C-arm units with limited image resolution. This practice is no longer acceptable because fluoroscopy and saved image quality are key to accurate diagnosis and management. High-quality ERCP imaging requires resolution equivalent to that for neuroradiology (brain blood vessels). Resolution of greater than 2.5 line pair per millimeter is strongly recommended for both fluoroscopy and final images (Fig. 37.4). This resolution is best accomplished with smaller diameter image intensifiers of 6 to 9 inches.

Fig. 37.3 Room set-up with C-arm x-ray unit. Table tilt and cradle, C-arm tilt, and rotation offer viewing in multiple angles. Note lead apron drape from image intensifier. Note see-through lead shield near the head of the patient.

Fig. 37.4 Phantom used in determining line pair resolution during fluoroscopy or image acquisition. Greater than 2.5 line pair resolution is recommended for optimal endoscopic retrograde cholangiopancreatography (ERCP) resolution.

(Courtesy of Joe Edmiston, Indiana University Medical Center.)

Radiation safety standards should be followed.²⁵ Monitoring of personal exposure and review of methods to limit exposure are needed. Attention to coning the field of view to the area of interest is good practice. Lead aprons or shields around the patient limit x-ray beam scatter. Use of newer generation pulse fluoroscopy gives intermittent viewing, which is slightly jerky but often adequate with one-tenth the radiation exposure. Appropriate lead aprons, lead glasses, and thyroid shields are recommended (Fig. 37.5).

Fig. 37.5 Endoscopy assistant with lead apron, thyroid shield, and lead glasses for optimal radiation safety.

Patient Positioning, Preparation, and Sedation

Most centers prefer to have the patient positioned in a prone or slightly left lateral decubitus position on a fluoroscopic table. Less often, supine position is preferred, such as in patients with recent abdominal incisions, patients with multiple abdominal drain tubes, and patients undergoing Billroth II procedures.²⁶ Intravenous access and monitoring equipment for blood pressure, pulse, and pulse oximetry are needed. Electrocardiogram (ECG) monitoring is desirable for patients with angina or a history of a cardiac arrhythmia and in other less stable patients.

Sedation and analgesia are achieved by slow intravenous administration of diazepam (10 to 40 mg), midazolam (2 to 10 mg), and meperidine (25 to 150 mg) or fentanyl (50 to 150 mg). The general ranges mentioned here are given over a 30- to 60-minute examination. Droperidol (2.5 to 10 mg) is a common supplement or alternative, particularly for alcoholics or persons regularly taking narcotics or benzodiazepines.²⁷ However, more recent concerns about arrhythmias and Q–T interval prolongation have limited the use of droperidol for endoscopy. Our policy is to use droperidol routinely for patients whose baseline ECG has a normal corrected Q–T interval.²⁸ More recently, propofol has been used for deep sedation and may offer better procedure tolerance and a much shorter recovery time than standard sedation. Propofol use, when administered by endoscopists and endoscopy nurses, is apparently safe for standard upper GI endoscopy and colonoscopy but has not been well studied for ERC.^29–31

Visual monitoring in a darkened ERCP room with fluoroscopy equipment draped over the patient raises some safety concerns for ERC use. Topical pharyngeal anesthetic spray probably decreases gagging in patients. An antiperistaltic drug (e.g., glucagon or atropine) to inhibit duodenal motility is commonly needed. Drugs to treat bradycardia (e.g., atropine) and high blood pressure (e.g., labetalol) should be immediately available. Benzodiazepine and narcotic reversal agents should be immediately available in an “easy to administer” format. A fully equipped resuscitation cart must be close by. Pediatric cases can be done with success similar to adults. We prefer to use the pediatric endoscope with a diameter less than 8 mm for children weighing less than 12 kg, but we use the standard 10-mm diameter endoscope for all larger children.

Upper Gastrointestinal Endoscopy

Initially, a brief endoscopic examination of the esophagus, stomach, duodenum, and major duodenal papilla is done. The finding of a large ulcer or neoplasm may cancel the need for ERCP. One should attempt to exit the stomach with as little residual intragastric air as possible because a deflated stomach permits better en face papilla views. Other findings, such as tumor infiltrating the proximal descending duodenum, varices, a pseudocyst pressing on the gut wall, or edema of the medial wall of the duodenum, help to quantitate or localize disease processes. The major papilla is usually located on the medial aspect of the mid-descending duodenum but may reside anywhere from the duodenal bulb to the transverse duodenum. Care should be taken to observe for major papilla abnormalities (e.g., tumor, edema, enlarged orifice from stone or mucus passage). The location of orifices should be noted. A brief examination of the minor papilla may be helpful later in the examination if initial ERCP via the major papilla fails.

Before attempts at cannulation, fluoroscopic visualization (or still image acquisition) of the field of interest should be performed to look for stents, calcifications, masses, and residual contrast material (Fig. 37.6). The choice of initial cannulation tool is a personal preference (similar to choosing a tennis racket or golf club). One may begin with a simple single-lumen 5-Fr polyethylene catheter, without a guidewire, in many cases. The relative flexibility (not rigid), maneuverability, low cost, and simplicity are attractive features. A manometry catheter is initially used if ERCP findings are likely to be nonspecific or normal and if manometry is likely to be potentially helpful. If a sphincterotomy is almost certainly needed, a sphincterotome is a good starting tool. If the orifice appears small, a more tapered tip catheter or sphincterotome may be chosen. A few centers prefer various shaped metal tip catheters. Two-lumen or three-lumen catheters or sphincterotomes may be preferred because they have a separate lumen for a guidewire and contrast medium. A guidewire may be used at any point to aid cannulation or maintain intraductal stability. For biliary cannulation, 0.025-inch or 0.035-inch diameter wires are preferred. Soft-tipped wires have the advantage of less tissue trauma (e.g., fewer submucosal or other extraductal dissections). The specific devices used are much less important than the skill of the endoscopist (Fig. 37.7).

Fig. 37.6 Plain x-ray film of right upper quadrant showing post–shock wave lithotripsy pancreatic calcifications (arrows) and residual biliary stent. This film serves as a background view for all subsequent contrast agent injections.

Fig. 37.7 A, A well-equipped biliary diagnostic unit contains a wide variety of guidewires with varying characteristics, different sizes (0.018-inch, 0.025-inch, and 0.035-inch diameter), variable hydrophilic tips, and some groomable wires whose tip shape can be changed. Also shown are 5-Fr catheters with variable tip taper or metal tip (bottom). B, Stainless steel wire of 0.035-inch diameter (with polytef [Teflon] coating) ungroomed (straight). C, Same wire as shown in B except tip has been manually groomed to curl cephalad for biliary cannulation assistance.

If the major papilla is not initially evident, gentle lifting of folds, greater air distention, and use of glucagon to inhibit peristalsis would likely expose the structure. If duodenal diverticula are present, the major papilla is most commonly on the diverticular rim, but the papilla is within the diverticulum per se in approximately 5% to 10% of cases (Fig. 37.8). The major papilla is then cannulated. Orientation of the catheter tip toward the 11 o’clock to 12 o’clock position (Fig. 37.9) would more likely enter the bile duct; orientation of the catheter toward the 3 o’clock to 5 o’clock position would more likely enter the pancreatic duct. Biliary orifice location may vary from 10 o’clock to 2 o’clock. Cannulation may be initially done by gentle impaction of the catheter tip in the papillary orifice. Deep cannulation (>1 cm penetration of the catheter into the duct) more securely establishes an intraductal position, which allows contrast agent injection, fluid aspiration, patient position changes, and endoscope position changes without loss of access to the duct.

Fig. 37.8 A and B, Difficult biliary cannulation cases. Major papilla associated with duodenal diverticula. The papilla is most commonly on the rim of the diverticulum but may be located fully within the diverticulum and be much more problematic to cannulation. A, Bilobed diverticulum (white arrows) and major papilla orifice (black arrow). B, Papilla on 6 o’clock rim of diverticulum.

Fig. 37.9 A, Endoscopic view of 5-Fr catheter oriented toward the 11 o’clock position of the major papilla. B, The bile duct has been entered and bile aspiration confirmed by yellow color in the catheter lumen. C, The catheter was oriented more toward the 3 o’clock position to enter the pancreas.

Selective Deep Biliary Cannulation

Pancreatic cannulation is easier than biliary cannulation. Selective biliary entry is mandatory in most cases of biliary pathology. We often start with a standard 5-Fr catheter and add a guidewire or a sphincterotome for assistance. If the cannulation angle fails to achieve adequate cephalad orientation, a sphincterotome or curved top guidewire generally helps to achieve that angle. There are increasing observations that initial use of a guidewire facilitates cannulation and decreases post-ERCP pancreatitis.³²