Introduction

Endoscopic retrograde cholangiopancreatography (ERCP) is the standard approach to gaining access to the biliary and pancreatic ductal systems, typically with therapeutic goals of stone extraction or decompression of an obstructed duct. However, in a small subset of cases anatomic constraints imposed by disease states or abnormal anatomy preclude ductal access via conventional ERCP. Previously such situations prompted a percutaneous or surgical approach to therapy. However, with the advent of endoscopic ultrasonography (EUS), with its unique capabilities of accurate imaging of the pancreas and biliary systems as well as ductal access via transmural puncture, there is now an alternative to surgical and percutaneous radiologic approaches in situations inaccessible to ERCP: endosonographic cholangiopancreatography (ESCP). This article reviews the background, technical details, published experience, and role of ESCP in clinical practice.

Background

ERCP is regarded as the standard, first-line method to achieve decompression of an obstructed biliary or pancreatic ductal system, with a technical success rate exceeding 90% and complication rate less than 10%. However, surgically altered anatomy, variations of native anatomy, periampullary diverticula, and malignancy are circumstances that may preclude ERCP. In these situations, alternative means of biliary decompression include percutaneous transhepatic biliary drainage and surgical intervention. Percutaneous biliary drainage has a complication rate of 10% to 30%, with possible development of bile leak, bleeding, fistula formation, peritonitis, cholangitis, and stent occlusion; the death rate associated with percutaneous biliary drainage has been reported to be as high as 6%. Although surgical biliary drainage is effective, it has been associated with a 2% to 5% rate of death and a 17% to 37% rate of morbidity.

For highly experienced operators, reported success rates of pancreatic duct cannulation range from 90% to 98% for the major papilla and 90% to 95% for the minor papilla. Several anatomic factors can be responsible for unsuccessful pancreatic duct cannulation at ERCP. For example, the papilla can be inaccessible because of either luminal obstruction of the upper gastrointestinal (GI) tract or surgically altered anatomy. Additional factors include inability to identify the pancreatic orifice of either the major or minor papilla, or benign or malignant strictures that impede deep cannulation of the pancreatic duct. Whereas a percutaneous approach in the setting of failed endoscopic biliary drainage is widely available and is associated with high success rates, an analogous percutaneous approach for pancreatic ductal access is neither as technically feasible nor as widely available. This shortcoming is due to multiple factors, including the deeper location of the pancreas compared with that of the intrahepatic bile ducts, smaller caliber ducts, and less compelling risk-benefit profiles of pancreatic ductal therapy.

Extensive experience with EUS-guided fine-needle aspiration (FNA) in and around the pancreas and extrahepatic bile duct provided the foundation for experimentation with EUS-guided biliary and pancreatic drainage. In contrast to a percutaneous approach, the proximity of these ducts to the gastroduodenal lumen, and therefore to the echoendoscope, is a distinct advantage of EUS-guided techniques. All experienced endosonographers are familiar with the close proximity of the common bile duct (CBD) and main pancreatic duct to the upper GI lumen. Indeed, in typical EUS-FNA cases, efforts are made to avoid these structures, which may lie near a targeted tumor mass.

Experience with EUS-guided biliary and pancreatic duct procedures has been expanding gradually since its inception, with the first description of EUS-guided cholangiopancreatography (ESCP) by Wiersema and colleagues in 1996. Six variants of EUS-guided biliary and pancreatic duct drainage have been reported based on the ESCP paradigm ( Fig. 1 ): ductal access under EUS coupled with ERCP-like instrumentation of the ducts under fluoroscopy. Just as ERCP gained wide acceptance because of its efficacy in clinical situations that previously necessitated more invasive approaches, in situations where ERCP is not possible, ESCP, another entirely endoscopic approach that obviates surgery or percutaneous intervention, has enormous potential and promise.

The 3 potential ESCP access sites: intrahepatic (1, 2), extrahepatic (3, 4), and pancreatic (5, 6). After ductal access through any of them, drainage can be accomplished transmurally over an intraductal guide wire (1, 3, 6) via hepaticogastrostomy (1), choledochoduodenostomy (3), or pancreaticogastrostomy (6). Transpapillary guide-wire placement (2, 4, 5) allows both retrograde access via rendezvous ERCP and antegrade stent placement for biliary (2, 4) or pancreatic duct drainage (5). Rendezvous requires an accessible papilla and is preferable in benign disease. Antegrade transpapillary ESCP suits complex postoperative anatomy well, particularly when performed for palliation of malignant obstruction. Three access sites combined with 2 drainage routes gives rise to the 6 variant ESCP approaches.

( Reprinted from Perez-Miranda M, de la Serna C, Diez-Redondo P, et al. Endosonography-guided cholangiopancreatography as a salvage drainage procedure for obstructed biliary and pancreatic ducts. World J Gastrointest Endosc 2010;2:214; with permission from Baishideng.)

Background

ERCP is regarded as the standard, first-line method to achieve decompression of an obstructed biliary or pancreatic ductal system, with a technical success rate exceeding 90% and complication rate less than 10%. However, surgically altered anatomy, variations of native anatomy, periampullary diverticula, and malignancy are circumstances that may preclude ERCP. In these situations, alternative means of biliary decompression include percutaneous transhepatic biliary drainage and surgical intervention. Percutaneous biliary drainage has a complication rate of 10% to 30%, with possible development of bile leak, bleeding, fistula formation, peritonitis, cholangitis, and stent occlusion; the death rate associated with percutaneous biliary drainage has been reported to be as high as 6%. Although surgical biliary drainage is effective, it has been associated with a 2% to 5% rate of death and a 17% to 37% rate of morbidity.

For highly experienced operators, reported success rates of pancreatic duct cannulation range from 90% to 98% for the major papilla and 90% to 95% for the minor papilla. Several anatomic factors can be responsible for unsuccessful pancreatic duct cannulation at ERCP. For example, the papilla can be inaccessible because of either luminal obstruction of the upper gastrointestinal (GI) tract or surgically altered anatomy. Additional factors include inability to identify the pancreatic orifice of either the major or minor papilla, or benign or malignant strictures that impede deep cannulation of the pancreatic duct. Whereas a percutaneous approach in the setting of failed endoscopic biliary drainage is widely available and is associated with high success rates, an analogous percutaneous approach for pancreatic ductal access is neither as technically feasible nor as widely available. This shortcoming is due to multiple factors, including the deeper location of the pancreas compared with that of the intrahepatic bile ducts, smaller caliber ducts, and less compelling risk-benefit profiles of pancreatic ductal therapy.

Extensive experience with EUS-guided fine-needle aspiration (FNA) in and around the pancreas and extrahepatic bile duct provided the foundation for experimentation with EUS-guided biliary and pancreatic drainage. In contrast to a percutaneous approach, the proximity of these ducts to the gastroduodenal lumen, and therefore to the echoendoscope, is a distinct advantage of EUS-guided techniques. All experienced endosonographers are familiar with the close proximity of the common bile duct (CBD) and main pancreatic duct to the upper GI lumen. Indeed, in typical EUS-FNA cases, efforts are made to avoid these structures, which may lie near a targeted tumor mass.

Experience with EUS-guided biliary and pancreatic duct procedures has been expanding gradually since its inception, with the first description of EUS-guided cholangiopancreatography (ESCP) by Wiersema and colleagues in 1996. Six variants of EUS-guided biliary and pancreatic duct drainage have been reported based on the ESCP paradigm ( Fig. 1 ): ductal access under EUS coupled with ERCP-like instrumentation of the ducts under fluoroscopy. Just as ERCP gained wide acceptance because of its efficacy in clinical situations that previously necessitated more invasive approaches, in situations where ERCP is not possible, ESCP, another entirely endoscopic approach that obviates surgery or percutaneous intervention, has enormous potential and promise.

The 3 potential ESCP access sites: intrahepatic (1, 2), extrahepatic (3, 4), and pancreatic (5, 6). After ductal access through any of them, drainage can be accomplished transmurally over an intraductal guide wire (1, 3, 6) via hepaticogastrostomy (1), choledochoduodenostomy (3), or pancreaticogastrostomy (6). Transpapillary guide-wire placement (2, 4, 5) allows both retrograde access via rendezvous ERCP and antegrade stent placement for biliary (2, 4) or pancreatic duct drainage (5). Rendezvous requires an accessible papilla and is preferable in benign disease. Antegrade transpapillary ESCP suits complex postoperative anatomy well, particularly when performed for palliation of malignant obstruction. Three access sites combined with 2 drainage routes gives rise to the 6 variant ESCP approaches.

( Reprinted from Perez-Miranda M, de la Serna C, Diez-Redondo P, et al. Endosonography-guided cholangiopancreatography as a salvage drainage procedure for obstructed biliary and pancreatic ducts. World J Gastrointest Endosc 2010;2:214; with permission from Baishideng.)

Methods of ESCP procedures

Selection of Access Site and Drainage Route

Selection of access site

Several variables influence the choice of access site for ESCP. In most biliary ESCP cases, the EUS access site is determined by the level of obstruction (hilar versus distal extrahepatic bile duct) and by the feasibility of imaging the CBD under EUS (difficult to impossible in patients with prior gastrectomy or indwelling duodenal stents) or the intrahepatic bile duct (which needs some degree of dilation) ( Fig. 2 ). These anatomic constraints explain why only a single access site (intrahepatic or extrahepatic) is available in about 80% of biliary ESCP cases. In practice, the possibility of choosing between intrahepatic or extrahepatic bile-duct puncture only arises in the remaining 20% of biliary ESCP patients. For pancreatic ESCP cases, endosonographic access to the main pancreatic duct is typically obtained via transgastric puncture, although in cases where transduodenal access is feasible it is occasionally chosen by some investigators.

Extrahepatic access is suitable for distal biliary obstruction in patients with native antroduodenal anatomy despite the presence of ascites or nondilated intrahepatic ducts (B). Any prior surgery involving distal gastrectomy with gastrojejunostomy (C) precludes EUS imaging of the CBD. Similarly, a hilar stricture with dilation of the left ductal system (A) requires intrahepatic access. Some of these patient specifics are present in 80% of carefully selected ESCP candidates, which limits the possibly overrated issue of operator’s choice of approach to 20% of cases.

( Reprinted from Perez-Miranda M, De la Serna C, Diez-Redondo P, et al. Endosonography-guided cholangiopancreatography as a salvage drainage procedure for obstructed biliary and pancreatic ducts. World J Gastrointest Endosc 2010;2:217; with permission from Baishideng.)

Selection of drainage route

The choice between transpapillary and transmural drainage is influenced by the patient’s anatomy and diagnosis (eg, CBD stone versus malignant stricture) and by operator preference. Patient-related factors cannot be altered in a given case other than by abandoning the procedure (ie, considering ESCP a failure if transpapillary guide-wire passage is unsuccessful and rendezvous is the only approach considered ) and opting for alternative therapies. Technique and operator skill, however, can evolve and improve with practice. Whereas some investigators adhere to a single approach, such as rendezvous drainage only or transduodenal access only, those with broader experience in alternative approaches may be able to salvage a greater proportion of failed ERCPs by means of ESCP.

ESCP Transpapillary Biliary Drainage (Rendezvous and Antegrade)

ESCP transpapillary biliary drainage entails gaining needle access to the intrahepatic or extrahepatic bile ducts under EUS guidance, followed by contrast injection (cholangiography), placement of a guide wire into the bile duct, then antegrade advancement of the guide wire across the native papilla (see Fig. 1 ). Subsequent biliary drainage is then effected either via a retrograde approach to the papilla (ie, ERCP) or EUS-guided rendezvous technique. Alternatively, drainage can be provided via an antegrade approach, typically following initial transgastric access into the intrahepatic system in patients with postoperative upper GI anatomy, for example, antegrade transgastric stent insertion or balloon dilation in patients with a strictured hepaticojejunostomy, or hilar lymph node recurrence causing obstructive jaundice after Roux-en-Y gastrectomy for gastric cancer ( Fig. 3 ). For ESCP rendezvous, endoscopic access to the papilla is a prerequisite. Usually this technique is prompted by obstruction or benign anatomic distortion of the native papilla, which precludes endoscopic retrograde biliary access. EUS-guided placement of a guide wire across the papilla then facilitates ERCP and conventional biliary therapy, for example, sphincterotomy and stone removal after failed cannulation caused by an intradiverticular papilla. For any kind of transpapillary drainage (antegrade or rendezvous) antegrade guide-wire passage from the puncture site into the small bowel is usually necessary, requiring a nontransected duct. An exceptional case of successful rendezvous drainage of a transected bile duct has been reported.

Antegrade biliary stent insertion after intrahepatic EUS-guided access. Biliary obstruction after Roux-en-Y subtotal gastrectomy for gastric cancer caused by periportal lymph node recurrence. Note how after initial needle access the guide wire coils at the upper margin of the stricture and goes toward the right hepatic duct ( A ). Manipulation with a flexible catheter manages to redirect the guide wire downstream ( B ), allowing antegrade stent insertion ( C ) and deployment. Contrast injection after stent deployment demonstrates proper placement and function ( D ).

Guide-wire manipulation

The limiting step for transpapillary ESCP drainage is guide-wire manipulation. The EUS needle does not allow the same free interplay over a guide wire as flexible ERCP catheters do, because the needle is rigid and has a sharp cutting edge. Repetitive or overly rapid to-and-fro movements of the needle over the wire risk shearing the guide wire or losing needle access to the duct.

Extrahepatic access for ESCP rendezvous

EUS and fluoroscopy should be used to identify an access site as close to the papilla as possible, with a tangential needle orientation to the extrahepatic bile duct, before the actual puncture. Postpuncture repositioning of the echoendoscope may be possible in cases with a largely dilated duct (eg, CBD above distal malignancy), although this carries the risk of losing needle access and possible procedural failure.

Intrahepatic access for rendezvous and antegrade ESCP

Transpapillary guide-wire passage is usually more demanding from an intrahepatic (transgastric) than an extrahepatic (transduodenal) access site. After extrahepatic access, the guide wire can only pass either up or down the CBD. By contrast, after intrahepatic access it may pass peripherally to another left branch at every confluence, or to the right lobe ducts at the confluence of the right and left main hepatic ducts. Therefore, transpapillary guide-wire passage with intrahepatic ESCP often requires dilation of the puncture track to a degree similar to that required for transmural drainage, to allow intraductal passage of catheters or sphincterotomes. These more maneuverable devices function to direct the guide wire toward the CBD and across the stricture and/or papilla. Traversing the papilla (or anastomosis) antegradely with a guide wire may require repeat needle puncture(s), reorientation, and different guide wires. Despite all this instrumentation the process may end up in failure, particularly when antegrade guide-wire passage across the papilla is tried after pancreatic duct needle access (see later discussion).

Scope exchange and retrograde guide-wire access for ESCP rendezvous

When guide-wire passage across the papilla is achieved, several loops of the wire should be advanced into the small bowel lumen to minimize the risk of dislodgment. For a rendezvous approach, the echoendoscope (with the needle attached) is removed carefully while the assistant feeds the wire into the needle at the same rate at which the endoscopist withdraws the scope-needle assembly. The position of the guide wire is monitored fluoroscopically to prevent both looping in the stomach and dislodgment of the transpapillary looped wire from the small bowel (duodenum, or jejunum in patients with hepaticojejunostomy). After EUS scope removal, a duodenoscope (or another scope of adequate length in patients with postoperative upper GI anatomy) is advanced alongside the guide wire while the assistant holds it under gentle traction from the patient’s mouth to prevent looping.

Classic rendezvous

Once the papilla is reached with a duodenoscope, the transpapillary guide wire can be grasped with a polypectomy snare or a rat-tooth forceps and retrieved upwards through the scope working channel, while the assistant feeds the guide wire from its proximal end into the patient’s mouth in coordination. During the process of guide-wire retrieval up the scope working channel, considerable friction is encountered, which may result in guide-wire loss from the grasp of the snare or forceps. To avoid this friction and its attendant risk, some investigators take the alternative step of removing the duodenoscope and the guide wire with a snare. Once the endoscope and guide wire exit from the patient’s mouth, the endoscope is backloaded over the wire down to the papilla. Whatever the method of guide-wire retrieval up the working channel (with the endoscope inside or outside of the patient), standard ERCP devices can be threaded over the wire once it has exited from the endoscope channel. This technique is called classic rendezvous.

Parallel rendezvous

Alternatively, once the duodenoscope reaches the papilla, a sphincterotome can be used for cannulation alongside the ESCP-placed wire (parallel rendezvous). Although this approach saves the time-consuming and often cumbersome step of guide-wire retrieval through the duodenoscope, its disadvantage is that it precludes dual traction (from the mouth end and from the endoscope end of the wire). For certain tight strictures (hilar bile duct or main pancreatic duct) that require stenting via ESCP, dual traction is a very useful ancillary technique that can obviate labor-intensive dilation before stenting. Failed transpapillary stenting after fastidious ESCP rendezvous has been reported that may have been avoided via use of dual guide-wire traction.

Non-rendezvous transpapillary ESCP drainage

Antegrade

The hurdles of guide-wire manipulation with regard to antegrade transpapillary passage and retrograde retrieval have been detailed above, in particular the need to dilate the needle access tract to pass flexible devices that effectively redirect the guide wire antegradely across the stricture and the papilla in cases of intrahepatic access (see Fig. 3 ). Given the impossibility of imaging the CBD under EUS in patients with gastrectomy, intrahepatic access is the only one possible in most patients with postoperative upper GI anatomy. In these cases with long afferent limbs the papilla can be reached with enteroscopes, adding time and complexity to and already labor-intensive procedure. Antegrade stent insertion, or balloon dilation, over the transpapillary guide wire (as in percutaneous stent insertion) seem less cumbersome in this setting.

Retrograde

A simpler relatively overlooked approach to achieving retrograde transpapillary ductal access by ESCP has been described. In some cases, either free-hand or standard wire-guided cannulation can be achieved despite prior unsuccessful ERCP, after the obstructed duct has been injected via ESCP with contrast medium or a mixture of contrast medium and methylene blue. Whether this approach is a “salvage” repeat ERCP after failed ESCP or a de novo ESCP-guided ERCP from the outset, the underlying premise is to enhance the visibility of an otherwise inconspicuous papilla or provide a guide for cannulation.

ESCP Transmural Biliary Drainage (EUS-Guided Choledochoduodenostomy and Hepaticogastrostomy)

As in endoscopic pseudocyst drainage, transmural duct drainage at ESCP is achieved by placing a stent across the GI wall and intervening structures into the target duct. For the bile duct there are 2 distinct sites that are typically chosen to place a transmural stent: (1) through the wall of the duodenal bulb into the CBD (EUS-guided choledochoduodenostomy [CDS]) or (2) below the cardia into the left hepatic duct (EUS-guided hepaticogastrostomy [HGS]). The terms CDS and HGS may not be literally accurate in certain cases, for example, after total gastrectomy and esophagojejunostomy whereby a transmural stent into the left hepatic duct is placed across the jejunal or distal esophageal wall, or when a transmural stent into the CBD enters the GI lumen through the wall of distal antrum rather than the duodenum.

EUS-guided choledochoduodenostomy

EUS-guided CDS involves stent placement across the duodenal wall into the extrahepatic bile duct. This procedure is considered in situations where conventional biliary cannulation and drainage is not possible, most often because of a tumor mass that either precludes luminal access to or obliterates the major papilla.

The linear-array echoendoscope is positioned in the long position, along the greater gastric curve, with the tip of the echoendoscope directed toward the hepatic hilum. This position allows endosonographic visualization of the dilated extrahepatic bile duct ( Fig. 4 ). A 22-gauge or 19-gauge EUS-FNA needle is used to puncture the extrahepatic bile duct, under EUS guidance. After withdrawal of the stylet, bile is aspirated through the needle and a cholangiogram is obtained. Cholangiography is useful to confirm biliary access and to facilitate correct guide-wire placement. The guide wire (preferably 0.025-in or 0.035-in, requiring a 19-gauge needle, or 0.018-in if using a 22-gauge needle) is advanced retrogradely into the intrahepatic biliary tree. Dilation of the transmural tract is then performed either with tapered biliary dilation catheters (6F, 7F, and 9F), needle knife, cystotome, or balloon dilation. Following tract dilation, a plastic or covered self-expandable metal stent is inserted through the choledochoduodenostomy over the guide wire, using similar techniques as for traditional ERCP stent placement.

Only gold members can continue reading. Log In or Register to continue

Share this:

• Click to share on Twitter (Opens in new window)
• Click to share on Facebook (Opens in new window)

Related posts:

Therapeutic and Advanced ERCP Is Rapidly Progressing Endoscopic Retrograde Cholangiopancreatography for Stone Burden in the Bile and Pancreatic Ducts Sampling at ERCP for Cyto- and Histopathologicical Examination Endoscopic Retrograde Cholangiopancreatography for Distal Malignant Biliary Stricture Complications of Endoscopic Retrograde Cholangiopancreatography Endoscopic Retrograde Cholangiopancreatography

Stay updated, free articles. Join our Telegram channel

Join