Biliary interventions
Therapeutic intention
Choledocholithiasis
Stone extraction
Lithotripsy
Restoration of biliary drainage
Cholestasis
Restoration of biliary drainage
Biliary pancreatitis
Stone extraction
Cholangitis
Restoration of biliary drainage
Stenosis
Dilatation
Bougienage
Stenting
Leakage
Stenting
Sphincterotomy/lowering of transsphincteric pressure gradient
Bile duct tumor
Restoration of biliary drainage
Photodynamic therapy
Radiofrequency ablation
SOD
Sphincterotomy
Pancreatic interventions
Therapeutic intention
Pancreas divisum
Lowering of transsphincteric pressure gradient/minor sphincterotomy
Chronic pancreatitis
Dilatation
Bougienage
Stone extraction
Pseudocyst drainage
Leakage
Stenting
Sphincterotomy/lowering of transsphincteric pressure gradient
Intraductal tumors
Drainage
The overall most common biliary indication is suspected choledocholithiasis, with or without concurrent cholangitis and biliary pancreatitis or prior to planned cholecystectomy. Benign strictures occur in primary or secondary sclerosing cholangitis (PSC, SSC), postoperatively after cholecystectomy or liver transplantation, and can be treated by ERC. Malignant biliary strictures are often treated in a palliative setting. Postoperative or traumatic leakage of the common bile duct (CBD) or intrahepatic bile ducts is amenable to bridging or drainage. In sphincter of Oddi dysfunction (SOD), types I and II [dilated bile duct (I) and/or (II) elevated serum liver tests] respond to sphincterotomy in some patients.
Pancreatic interventions are less frequently required, especially since pancreatic contrast has been associated with a risk of post-ERCP pancreatitis. In chronic pancreatitis, dilatation of pancreatic duct stenosis and extraction of pancreatic stones are sometimes necessary. Some pseudocysts can be drained using a transpapillary «natural way.» Postoperative or traumatic pancreatic duct disruption can be treated in a multidisciplinary setting by endoscopic drainage.
Contraindications to ERCP are similar to other endoscopic interventions and pose relative contraindications in most patients. Careful weighing of the odds–risk ratio is mandatory, and written informed consent must be obtained in all cases.
4.1.2 Informed Consent, Adverse Events, and Prophylaxis
Adverse events are intrinsic to therapeutic endoscopy, and ERCP carries a specifically high risk relative to other endoscopic interventions. For consent, patients should be specifically informed about pancreatitis, bleeding, cholangitis, and perforation in addition to the general risks of therapeutic endoscopy.
Post-ERCP Pancreatitis
Post-ERCP pancreatitis (PEP) is the most frequent complication of ERCP (Dumonceau et al. 2010). It affects approximately 3.5% of patients after ERCP. Usually, its severity is mild to moderate (90% of patients), but PEP can be severe and on rare occasions lethal (Andriulli et al. 2007). The definition of PEP has not been entirely consistent throughout the literature. Most authors use new-onset or intensified abdominal tenderness after ERCP and rise of amylase to 3× upper limit of normal (ULN) (Anderson et al. 2012). The severity of pancreatitis is often graded according to the length of in-hospital stay (mild up to 3 days, moderate 4–10 days, severe >10 days, necroses, pseudocysts). A transient rise in serum amylase is often seen after ERCP, but this does not mandate intervention without clinical signs of pancreatitis.
Patient- and examiner-dependent variables confer risk factors for PEP (◘ Table 4.2). Multiple risk factors are synergistic and must be appreciated when indicating ERCP.
Table 4.2
Risk factors for post-ERCP pancreatitis
Patient-related risk factors | |
|---|---|
Definite | Probable |
(Suspected) SOD | Young age |
Female sex | Normal serum bilirubin |
Prior pancreatitis | Non-dilated bile ducts |
Lack of chronic pancreatitis | |
Examiner-related risk factors | |
Definite | Probable |
Precut sphincterotomy | Difficult biliary cannulation |
Pancreatic duct injection | Pancreatic sphincterotomy |
Ampullectomy | Biliary sphincter balloon dilatation |
Incomplete clearance of biliary stones |
Tip
The following measures help to reduce the PEP rate:
- 1.
Strict patient selection: given the relatively high risks associated with ERCP, ERCP should be restricted to patients with a high probability of need of intervention. Diagnostic ERCP should be replaced by less invasive imaging, wherever possible.
- 2.
- 3.
Modification of cannulation technique: the PEP risk can be reduced by fewer attempts at the papilla and guide wire-assisted deep cannulation (Tse et al. 2012). If contrast is injected into the pancreatic duct, the volume should be kept at a minimum. Prophylactic pancreatic stenting (e.g., 5 French) is protective especially in high-risk patients and after repeated contrast injection into the duct of Wirsung and helps to straighten the papilla for subsequent deep biliary cannulation (Mazaki et al. 2013). Five to ten days after insertion, spontaneous passage should be ascertained or the stent be removed.
Cholangitis
The risk of ERCP-associated cholangitis is about 1–3% (Rosien et al. 2011). In unselected patients, the rate of infectious complications is not reduced by prophylactic peri-interventional administration of antibiotics. Therefore, routine administration is not recommended. However, prophylactic antimicrobial therapy should be given after potentially incomplete drainage of contrasted bile ducts or in immunocompromised patients. Typical indications are ERC in PSC, Caroli’s syndrome, and cholangiocellular carcinoma involving segmental or multiple branches, in patients after liver transplantation (◘ Table 4.3). Antibiotic therapy can be administered before, during, or shortly after ERCP or can be continued according to calculated prior therapy. Such high-risk patients benefit from conservative contrast injection; complete cholangiography of intrahepatic ducts or use of forced contrast with balloon occlusion may not be advisable. Re-aspiration of contrast may also be helpful in this setting. Cholangioscopy, photodynamic therapy, intrabiliary radiofrequency ablation, or PTCD also carries an increased risk of septic complication and should trigger antibiotic prophylaxis.
Table 4.3
Indications for peri-interventional antibiotic prophylaxis in correlation to patient- and intervention-associated risk
Patient: indication for ERCP | Aim of prophylaxis | Prophylaxis recommended? |
|---|---|---|
Biliary obstruction/intervention, no concurrent cholangitis | Prevent cholangitis | |
Complete drainage | Not recommended | |
Incomplete drainige | Recommended (single shot) | |
Cholangitis | Prevent bacteremia/sepsis | Calculated/targeted therapy |
Biliary complications after liver transplantation | Prevent cholangitis | Recommended (single shot) |
Biliary intervention with increased risk for infection | Prevent cholangitis | Recommended (single shot) |
Communicating/sterile pancreatic cysts or necrosis (aspiration, drainage) | Prevent (pseudo-)cyst infection | Recommended (single shot) |
Immunocompromised patients | Prevent bacteremia | Recommended (single shot) |
Bleeding
ERCP-associated hemorrhage occurs in about 1% of patients and depends on the type of intervention and potential coagulation disorders. Mild bleeding after sphincterotomy is not uncommon and usually self-limiting and otherwise can be compressed by biliary stent insertion. Careful coagulation of the bleeding site can be performed during EST; sometimes spraying of (ice cold) adrenalin suspension is used. Diminutive bleedings can be treated after finishing the biliary intervention. If visualization is severely impaired by more severe bleeding, immediate therapy is advocated. Balloon compression can be helpful to localize the exact bleeding site. When injecting higher volumes of NaCl or placing clips for hemostasis, subtle care must be taken to not compromise drainage of the biliary and pancreatic system. Here, stenting is advised in most cases. Delayed bleeding can be seen up to 14 days after EST and often requires re-intervention.
Perforation
Perforation is a rare complication (0.1–0.5%) and may occur in three different settings: most frequently, the perforation is a consequence of an overly wide sphincterotomy. The perforation site is often visible, and/or contrast or air leakage can be identified fluoroscopically. Usually this requires termination of ERCP after insertion of a biliary drainage. In delayed perforation, the perforation site is smaller and toward the retroperitoneum. Therefore, usually there is no free air found on plain abdominal X-ray, and CT is required for diagnosis. Symptoms include postinterventional abdominal pain, often without a rise in amylase levels. Conservative therapy with broad spectrum antimicrobial therapy and nil per os is sufficient in over 90% of patients. Less frequently, perforation is a consequence of the intervention within the bile duct or forced wire manipulation. If recognized during the intervention, it should be treated by stenting. Perforation by the endoscope often occurs distant from the papilla. Risk factors include ERC in a postoperative situs such as Billroth II or Roux-en-Y anatomy. Some endoscopy units therefore perform (forward-viewing) EGD prior to the first in-house ERCP for identification of altered anatomy or for differential diagnosis (e.g., ulcers in abdominal pain).
Other Complications
Cardiopulmonary complications are rare. However, longer intervention times, deeper sedation, and (prone) position should be taken into account for patients at risk. Ambient air should not be insufflated into the bile ducts, since lethal pulmonary air embolism has been reported.
4.1.3 General Setting
Minimal requirements as to blood coagulation parameters correspond to those for other endoscopic interventions (cf. Appendix). In addition, bilirubin and other serum liver tests are indicative of the functional relevance of potential findings during ERC, and CRP and leucocytes help to determine the urgency to intervene.
Fluoroscopy is a central requirement for ERCP. The authors prefer side-inverted imaging, i.e., the patient’s right side is left on the screen, such as in conventional abdominal X-ray. Radiation protection is key, especially in repeated interventions and in younger patients/children. This includes optimal collimation and magnification of the region of interest (rule of thumb: aperture covers should be seen on all four sides of the image), pulsed rather than continuous fluoroscopy, and storage of fluoroscopy images with last-image hold function rather than full X-ray images, as well as age- and weight-adapted fluoroscopy and filter settings.
Staff requirements have to cover the enhanced need for instrumentation assistance and longer and deeper sedation. Therefore, in addition to the endoscopist, at least one more assistant is needed for instrumentation and one dedicated person for sedation. Well-trained cooperation with the assistant is essential for rapid and successful intervention. The patient can be in prone or supine position. The authors prefer prone position, as it facilitates access toward the papilla and stable position of the duodenoscope. Supine position may be advisable in cardiorespiratory or septic patients (potentially demanding rapid cardiopulmonary support), during general anesthesia, in spinal diseases, and early after abdominal surgery. The use of CO2 for insufflation (if not standard for all endoscopies) is recommended for longer interventions as it helps to reduce postinterventional bloating and abdominal pain, thereby facilitating differentiation from initial PEP.
A history of allergy to contrast agents usually does not mandate specific precautions, as the small intraluminal amounts of contrast agents usually do not trigger systemic allergic reactions. In a history of allergy even after intraductal contrast application, the use of low contrast volumes or 1:1 mixture with sterile NaCl, i.v. prednisolone (e.g., 100 mg), or dimetindene (e.g., 4 mg) may be considered.
If ERCP is performed in an emergency setting and/or outside regular office hours, the personnel may be less familiar with the specific requirements for ERCP. This increases the risk of failure and complications associated with ERCP. Usually, emergency ERCP cannot be performed in intensive care unit, since the use of mobile fluoroscopy devices limits performance outside the endoscopy suite (other than in emergency gastroscopy or colonoscopy). Therefore, postponing ERCP until the next morning or regular endoscopy hours is encouraged, whenever possible. In addition, intervention times should be limited in severely ill patients, such as in septic cholangitis. Here, a rapid first intervention to secure biliary drainage is recommended, and completion of diagnosis and therapy ensues as soon as the patient’s clinical situation is sufficiently stable.
4.1.4 ERCP in Selected Patients
Postoperative modification of the anatomy such as after Billroth II resection or Roux-en-Y anastomosis can pose a significant challenge to accessing the biliary system (◘ Fig. 4.1).
Fig. 4.1
Postoperative anatomy after Billroth II resection a, Roux-en-Y anastomosis b, and pylorus-preserving Whipple’s resection c
Tip
In such patients, initial endoscopy with a forward-viewing colonoscope with a large working channel (minimum 3.2 mm, preferably 3.8 mm) is recommended. This facilitates navigation toward the papilla/biliodigestive anastomosis, and the forward orientation of the working channel often corresponds to the intubation angle into the biliary system. In cases where a duodenoscope with an Albarran lever is preferred, endoscopes can be exchanged over a stiff guide wire.
Alternatively, balloon-guided enteroscopy can be used to access the biliodigestive anastomosis, although the postoperative situs can be challenging.
The use of a colonoscope allows utilization of most conventional ERCP accessories. For balloon-enteroscopy-guided ERCP, a specific instrumentarium is available that fits through the longer and smaller working channel. This may limit the ad hoc options for intervention, depending on local availability. In addition, stabilization and navigation in front of the papilla are limited. In patients with altered anatomy after Billroth II resection or Roux-en-Y anastomosis, the papilla is accessed from retrograde, i.e., in 180° rotation. For sphincterotomy in BII patients, if no dedicated Billroth sphincterotomes (with 180°-rotated cutting wire position) are available, needle-knife sphincterotomy over a pancreatic stent is recommended. After biliodigestive anastomosis, dilatation of the orifice is advisable (◘ Fig. 4.2). After bariatric surgery, enteroenterostomy can be quite distally hampering access toward the papilla.
Fig. 4.2
Biliodigestive anastomosis after hemihepatectomy for cholangiocellular carcinoma (cf. surgical clips and portal vein stent) with recurrent tumor manifestation and stenosis of the BDA a and distal bile duct b. In panel b, the tip of the colonoscope and the orientation for intubation (in the longitudinal colonoscope axis, using a balloon catheter) can be seen. A self-expanding metal stent is placed via the 3.8-mm colonoscope working channel, bridging the bile duct and BDA stenosis
ERCP in infants and children poses specific challenges and is usually limited to selected tertiary care centers. Choice of endoscopes must be tailored according to age and body weight. Specific pediatric duodenoscopes are available (◘ Fig. 4.3) but require specific accessories adapted to the limited working channel size. Usually, general anesthesia is used for pediatric ERCP.
Fig. 4.3
Duodenoscopes with outer diameters ranging from 13.7 to 7.5 mm (from left to right, pediatric duodenoscope with 2-mm working channel)
ERCP is not frequently requested during pregnancy in terms of absolute numbers, but hormonal changes predispose to biliary stones. Larger trials are not available, but case series report ERCP during pregnancy (Chan and Enns 2012). Exposure of the fetus to radiation is the major concern. Although no adverse events have been reported, exposure especially in the first trimester should be avoided whenever possible. Apart from minimization of fluoroscopy times and maximized collimation, lead shields under/on the mother’s lower abdomen help to minimize direct (but not indirect, scattered) radiation exposure of the fetus. The indication for ERCP can be consolidated by preinterventional EUS or MRCP. Radiation-free ERCP with visualization of deep cannulation and guide wire position by transabdominal ultrasound or with cholangioscopy has been reported in small case series.
4.2 Endoscopic Sphincterotomy: Primary Cannulation of the Papilla
Indications
As explained before, post-ERCP pancreatitis (PEP) is the most common complication from ERCP (Dumonceau et al. 2010). Cannulation of the native papilla is a strong risk factor for PEP. Both papillary edema after recurrent contacts with the papilla and unintended contrast injection into the pancreatic duct may result in an increased pressure gradient across the papilla, associated with the risk for parenchymal injury to the pancreas. PEP can pose a severe and potentially lethal complication and mandates a thorough benefit–risk assessment in ERCP indication.
Tip
Given the PEP risk, purely diagnostic ERCP is generally discouraged. Alternative imaging modalities such as EUS or MRCP are associated with significantly lower adverse event rates.
For this reason, a first ERCP in a patient with native papilla is usually planned as a therapeutic intervention (such as biliary stone removal, recanalization of stenoses, etc.) which usually requires prior sphincterotomy. ERCP in a patient with native papilla therefore usually includes indication for sphincterotomy. Sphincterotomy facilitates access into the respective ducts and enables stent insertion or stone extraction. Biliary stenting without sphincterotomy is only rarely indicated, such as in septic cholangitis (to shorten intervention times) or in patients with impaired coagulation. Some endoscopists refrain from biliary sphincterotomy in favor of insertion of a self-expanding metal stent.
Cannulation of the Native Papilla
Initial ERCP in a patient with native papilla usually requires sphincterotomy, as specified above. For deep cannulation we therefore start with a sphincterotome. Such a proceeding saves time and facilitates cannulation by making use of the bending properties of the sphincterotome. Guide wire-assisted deep cannulation of the bile duct is superior to contrast-guided cannulation with regard to both higher cannulation success and lower PEP rate and is especially recommended early in ERCP training. The ease of cannulation cannot be reliably predicted beforehand. Predictors of «easier cannulation» may be separated biliary and pancreatic orifices or macerated papillas after stone passage. Predictors of «difficult cannulation» may be papillas in diverticula or small or hard-to-identify papillas (in tumor in growth or in chronic pancreatitis) (◘ Fig. 4.4).
Fig. 4.4
Not all papillas are equal!
Guide wire-assisted cannulation of different types of native papillas can be facilitated in several ways:
Tip
Cannulation with a standard sphincterotome loaded with a soft hydrophilic guide wire (tip).
Insertion of the sphincterotome tip into the orifice for 2 mm and careful wire advancement (normal papilla).
Insertion of the sphincterotome into the orifice over 3–5 mm and careful wire advancement (large/mobile papilla).
The tip of the guide wire protrudes for about 1–2 mm from the cannula tip and is used for intubation of the orifice. The sphincterotome is used only to direct the wire (small papilla).
For biliary cannulation, the wire/sphincterotome should be inserted at the upper margin of the orifice. By flexing the sphincterotome, the angle of intended intubation (vs axis of the endoscope) should be adjusted to about 45–60°. Cannulation should be oriented toward 11 o’clock (this will also be the orientation of ensuing sphincterotomy). Fine-tuning can be achieved by subtle torquation of the duodenoscope or change in the access orientation with the small wheel. Since the intramural part of the CBD can be siphon-shaped, careful traction on the sphincterotome or slight withdrawal of the duodenoscope can be used to straighten the distal aspect of the CBD. Intubation of the duct of Wirsung has to follow a different (larger) angle and orientation of the cannulation of the orifice toward the 3 o’clock position (◘ Fig. 4.5).
Fig. 4.5
a Anatomy of the biliary and pancreatic duct seen (ventro-dorsal view). b Papillary anatomy as seen from the duodenoscope, with orientation of biliary sphincterotomy (11 o’clock) and pancreatic sphincterotomy (2–3 o’clock)
Cannulation of the minor papilla is more challenging in most patients, given the less stable duodenoscope position after slight withdrawal (◘ Fig. 4.6a). Intubation of the tiny papilla is often facilitated by using a small-caliber wire (e.g., 0.018″) and/or dedicated minor cannulation catheters.
Fig. 4.6
a Minor papilla identified as a small elevation 2–3 cm above the major papilla (left) closer to the duodenal bulb. b Retrograde access to the major papilla in BII anatomy using a pediatric colonoscope (emergency ERC with cholangitis and pus draining from the papilla)
Biliary cannulation in surgically altered anatomy may be challenging. After Roux-en-Y or BII resection, only retrograde access toward the papilla can be achieved. The direction for which biliary cannulation follows is rather plane angle (instead of 45–60° in unaltered anatomy). Therefore, a standard sphincterotome will not be oriented correctly, and «inverted» Billroth II sphincterotomes may be used. Correct orientation for cannulation is sometimes achieved more easily with forward-viewing endoscopes (such as single-/double-balloon enteroscopes, pediatric colonoscopes) than with duodenoscopes.
Cannulation of a native papilla is sometimes hard to achieve. In such cases, precut sphincterotomy is sometimes required. Precut sphincterotomy implies a small cut (initially about 2–5 mm) close to the papillary orifice for unroofing the biliary sphincter. Precut is performed in the 11 o’clock direction. Precut sphincterotomy can be performed with a needle knife or a precut sphincterotome. Fistulotomy (direct cut cranially of the orifice in a typical biliary orientation) is rarely required (impacted stone). If the guide wire repeatedly intubates the pancreatic duct, transpancreatic biliary sphincterotomy can be performed from the pancreatic orifice in the direction of the biliary duct. The wire can then be left in place to insert a pancreatic stent (serves also as PEP prophylaxis), and the pancreatic stent can be used to guide biliary cannulation (◘ Figs. 4.7 and 4.8).
