Endoscopic Ultrasound-guided cholangiopancreatography and rendezvous techniques

1.1. Patient selection 

Patients who present with biliary or pancreatic duct obstruction that failed conventional ERCP at a tertiary care centre by an experienced endoscopist should be considered for endoscopic ultrasound-guided ERCP (EUCP). Contra-indication includes coagulopathy and severe hemodynamic instability precluding general anaesthesia. Detailed cross sectional imaging of the pancreaticobiliary tree, as well as surrounding structures with CT or MRI is vital to identify the level of obstruction and to define the patient's anatomy. All patients should receive intravenous periprocedural antibiotics. Secondary to the duration and complexity of the procedure, patients should undergo general anaesthesia.

1.2. Endoscopist selection 

Since EUS-guided ERCP is a technically challenging procedure that bears a fair amount of risk when compared to conventional ERCP, it is mandatory that the endoscopist has expertise in both EUS and ERCP. This goal can be accomplished either with a single operator who is highly skilled at both EUS and advanced endoscopy, or by two different endoscopists, one with experience in interventional EUS, and the other in therapeutic ERCP. Furthermore, the procedure should be performed at a tertiary care centre where experienced pancreatobiliary surgeons and interventional radiologists are available in the event of a complication.

1.3. Techniques 

A linear-array echoendoscope with a working channel of at least 3mm should be selected. The Olympus GF-UCT 140 and the Pentax EG 38UT have working channels of 3.7 and 3.8mm, respectively, and are ideal for the placement of large diameter stents.

Puncture of the target duct is typically performed with either a 19- or a 22-gauge needle (EUSN-19-T or EUS-1-CS; Cook Endoscopy). The 19-gauge needle is preferred because it accommodates a 0.035-in. guidewire (Terumo; Boston Scientific, Natick, MA), which provides more control than the 0.018-in. guidewire (Pathfinder; Boston Scientific). Dilation of an enterocholedochal or pancreatic fistula is then accomplished using either a 4- or 6-mm wire-guided balloon catheter (MaxForce; Boston Scientific) or a 6F or 7F bougie (SBDC-6 or -7; Wilson-Cook, Winston-Salem, NC).

1.4. Intrahepatic approach 

The intrahepatic approach is performed with the echoendoscope positioned in the cardia or lesser curvature of the stomach to allow visualization of the dilated left intrahepatic biliary system. Once colour Doppler has excluded overlying vasculature, the EUS needle is advanced into the intrahepatic duct, bile is aspirated, and a small amount of contrast is injected to opacify the biliary tree, confirming position inside the bile duct (Fig. 1, Fig. 2). A guidewire is then advanced in an antegrade fashion through the EUS needle and into the bile duct (Fig. 3). With fluoroscopic and EUS guidance, the guidewire is manipulated beyond the biliary obstruction and across the ampulla into the duodenum. Once the guidewire has traversed the ampulla, the procedure can be completed in either an antegrade fashion or with a rendezvous technique.

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Fig. 1. Ultrasonographic view with colour flow Doppler of a dilated left hepatic before EUS-guided puncture.

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Fig. 2. Injection of contrast through the EUS needle, demonstrating successful opacification of the intrahepatic duct (fluoroscopic view).

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Fig. 3. A guidewire is advanced through the EUS needle and into the biliary tree across the stricture.

In an antegrade fashion, a 6 or 7F bougie or balloon catheter is utilized to dilate the tract (Fig. 4), followed by antegrade stent deployment across the stricture (Fig. 5).

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Fig. 4. Dilation of the tract between the stomach and the left intrahepatic duct in antegrade fashion.

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Fig. 5. Metal stent deployment across the distal stricture.

If the rendezvous technique is chosen, the echoendoscope must be carefully removed while leaving the guidewire in place. A duodenoscope is inserted and advanced to the duodenum, with visualization of the ampulla and the wire exit of the ampullary orifice. The wire is then grasped with a snare and withdrawn through the accessory channel. Since access to the common bile duct has been achieved, the procedure can be completed using standard ERC with stent placement.

If the guidewire cannot be advanced into the duodenum, a transenteric fistula can be created by dilating the tract with a 4–6mm wire-guided balloon catheter or a 6–7F bougie, followed by stent placement.

1.5. Extrahepatic approach 

To visualize the extrahepatic bile duct, the echoendoscope is not only typically positioned in the duodenum but can also be positioned in the distal antrum, depending on the anatomy. After colour Doppler is used to identify adjacent vasculature, the EUS needle is then inserted into the bile duct and the guidewire is advanced in an antegrade fashion across the ampulla and into the duodenum (Fig. 6, Fig. 7). The remainder of the procedure is similar to that described above for the intrahepatic approach.

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Fig. 6. Extrahepatic puncture of the common bile duct.

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Fig. 7. Advancement of the guidewire from the bile duct in an antegrade fashion during an extrahepatic approach.

1.5.1. EUS-guided pancreatic drainage 

By positioning the echoendoscope in the stomach, the main pancreatic duct is identified with EUS guidance and punctured with the EUS needle. A small amount of contrast material is injected and a pancreatogram is performed to confirm successful access to the pancreatic duct (Fig. 8). A guidewire is advanced through the needle and into the pancreatic duct, with subsequent antegrade advancement of the wire into the duodenum, if possible (Fig. 9). If the guidewire cannot be advanced in an antegrade fashion, it should be advanced retrograde into the pancreatic duct. After ductal access has been achieved, a pancreatogastric fistula is enlarged with a 6F or 7F bougie followed by balloon dilation with a 4- or 6-mm MaxForce dilator (Fig. 10). Intraductal strictures should be dilated with either the bougie or balloon catheter. A 7F stent is then placed through the pancreatogastric fistula (Fig. 11).

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Fig. 8. Pancreatogram demonstrating dilated pancreatic duct above a distal stricture.

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Fig. 9. Advancement of a guidewire in a antegrade fashion across the stricture.

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Fig. 10. Balloon dilation of the pancreatogastric fistula.

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Fig. 11. Placement of a 7F stent through the pancreatogastric fistula.

2.1. EUS-guided biliary drainage 

Wiersema et al. described the use of EUS-guided cholangiography in 10 patients in 1996 [24]. In his series, biliary opacification guided repeat ERC with precut sphincterotomy in 5 of 7 patients. In 2001, Giovannini et al. performed a choledochoduodenal fistula created under EUS guidance with transbulbar stent placement [34]. Two years later, Burmester et al. reported a series of 4 patients undergoing creation of a EUS-guided enterobiliary fistulae in 3 patients [35]. EUS-guided drainage of obstructed biliary ducts via a rendezvous technique was performed in 2 patients by Mallery et al. [36] Kahaleh et al. reported a series of 23 patients undergoing EUS-guided ERC, with biliary decompression achieved in 21 patients [37]. Most recently, our group has reported the largest study of EUS-guided ERC performed in 49 patients. The overall success rate was 84% (41/49), with an overall complication rate of 16%. 35 patients underwent the intrahepatic approach, with a success rate of 83% (29/35). 14 patients underwent the extrahepatic approach (including 5 of whom had initially undergone the intrahepatic approach but were converted to the extrahepatic approach), with success in 12/14 patients, or 86% [38]. Table 1 summarizes the published literature of EUS-guided biliary drainage to date with a cumulative success and complication rate of respectively 81/93 (87%) and 19/93 (20%).

Table 1. Published series of EUCP.

	Author	Year	No. of patients	Technique	Complications	Rate of successa
	Biliary drainage
	Burmester et al. [35]	2003	4	Intrahepatic (1), extrahepatic (2)	Bile leak (1)	75% (3 of 4)
	Mallery et al. [36]	2004	2	Extrahepatic (2)	Wire passed out of bililary lumen (1)	100% (2 of 2)
	Puspok et al. [40]	2005	6	Extrahepatic (6)	None	83% (5 of 6)
	Bories et al. [41]	2007	11	Intrahepatic (11)	Ileus (1), Stent shortening (2), early blockage (1)	91% (10 of 11)
	Will et al. [42]	2007	8	Intrahepatic (7), extrahepatic (1)	Slight pain (2), cholangitis (1)	88% (7 of 8)
	Tarantino et al. [43]	2008	8	Extrahepatic (8)	Death from cirrhosis (1)	100% (8 of 8)
	Yamao et al. [39]	2008	5	Extrahepatic (5)	Pneumoperitoneum (1)	100% (5 of 5)
	Maranki et al. [38]	2009	49	Intrahepatic (35), extrahepatic (14)	Biliary peritonitis (1), pain (1), pneumoperitoneum (4), aspiration pneumonia (1), self-resolving bleeding (1)	84% (41 of 49)
	Pancreatic drainage
	Francois et al. [47]	2002	4	Pancreaticogastrostomy (4)	Stent dislocation (1)	100% (4 of 4)
	Kahaleh et al. [48]	2003	2	Pancreaticogastrostomy (2)	Haematemesis due to stent adjacent to vessel (1)	100% (2 of 2)
	Mallery et al. [36]	2004	4	Rendezvous (4)	Transient fever (1)	25% (1 of 4)
	Papachristou et al. [49]	2007	2	Rendezvous (2)	None	100% (2 of 2)
	Kahaleh et al. [51]	2007	13	Pancreaticogastrostomy (10)	Bleeding (1), Contained perforation (1)	77% (10 of 13)
	Tessier et al. [52]	2007	36	Pancreaticogastrostomy (26), Pancreaticobulbostomy (7)	Haematoma (1), pancreatitis (1)	92% (33 of 36)
	Will et al. [53]	2007	12	Pancreaticogastrostomy (5), rendezvous (4)	Pain (4), bleeding (1), perforation (1), pseudocyst (1)	75% (9 of 12)

a Success as defined by adequate drainage of the applicable duct.

The main complications associated with EUS-guided biliary drainage include pneumoperitoneum, post-procedure pain, and bleeding, most of which tend to be managed conservatively. The risk of bile leak and perforation leading to biliary peritonitis was found to be fairly small based on the reported case series. Of the 93 cases reported, there were 5 cases of pneumoperitoneum, 1 biliary leak, 1 case of biliary peritonitis and 1 case where the wire was passed outside of the bile duct lumen [35], [36], [38], [39]. There was also 1 case of ileus, 2 cases of stent malfunction, 1 early blockage, 1 death from complications of cirrhosis, 3 episodes of pain, 1 case of cholangitis, 1 aspiration pneumonia, and 1 case of self-resolving bleeding [38], [40], [41], [42], [43]. The overall complication rate in these 93 cases was 20% (19/93).

2.2. EUS-guided pancreatic drainage 

In 1996 Wiersema [24] and Gress et al. [44] each reported one case of EUS-guided pancreatography. One approach to achieving pancreatic drainage involves the creation of a pancreaticoenteric fistula followed by rendezvous [36], [45], [46]. Another technique requires the creation of a pancreaticogastric fistula as the main method for duct drainage [47], [48]. The rendezvous technique was described by Mallery et al. in whose series successful drainage was reported in only 25% (1 of 4) of patients [36] (Table 1). In 1 case, the pancreatic duct could not be punctured, and in 2 of the cases, the wire could not be advanced through the stricture. More recently, Papachristou et al. reported 2 cases of successful pancreatic drainage with the rendezvous technique in patients with nondilated pancreatic ducts [49]. When the pancreatic duct cannot be decompressed from the second portion of the duodenum, creation of a pancreaticogastric fistula is the preferred method to achieve duct drainage [50]. In a study at our institution, 13 patients with chronic pancreatitis and intractable pain were included; 7 of these patients had prior surgical diversions [51]. Successful creation of a pancreaticogastric fistula was achieved in 10 (77%) patients, followed by stent placement. In 2 cases, the needle could not be oriented to allow advancement of the guidewire for access, thus no endoprosthesis was placed. Complications of the procedures included 1 case of bleeding requiring hemoclip placement and 1 case contained perforation that resolved spontaneously. Tessier et al. reported the largest retrospective series to date of 36 patients who underwent either pancreaticogastrostomy or pancreaticobulbostomy. Success was achieved in 92% of cases (33 of 36), and complications, including haematoma and severe pancreatitis, occurred in 2 patients [52]. In 2007, Will et al. reported 12 patients through 14 interventions who underwent EUS-guided pancreatic duct drainage [53]. Pancreatography was successful in all patients, and drainage of the pancreatic duct was achieved in 9 patients. The transgastric approach, with creation of a pancreaticogastric fistula, was done in 5 patients, whereas 4 patients underwent the rendezvous technique with subsequent ERCP. The complication rate was 43%, with post-procedural pain occurring in 4 patients, bleeding in 1 patient, and perforation in 1 patient.

Table 1 summarizes the published literature of EUS-guided pancreatic drainage to date with a cumulative success and complication rate of respectively 61/73 (83%) and 14/73 (19%).

EUCP has several advantages over percutaneous drainage, including the ability to visualize overlying vascular structures in real time using colour Doppler while attempting needle puncture of the biliary or pancreatic ducts, potentially decreasing vascular injury. EUCP allows drainage without the need for an external drain, which can be a source of infection and discomfort. While the reported complication rate for EUS-guided pancreatic drainage is somewhat high, the complication rate for EUS-guided biliary drainage is more favourable, making it an attractive alternative to PTC.