Techniques of biliary drainage for acute cholangitis: Tokyo Guidelines



# Introduction
Acute cholangitis may progress rapidly to a severe form, particularly in the elderly, and the severe form often results in a high mortality (level 4). 1-3 When Reynolds and Dargan 1 published their report, surgical operation was the only available treatment, and the mortality rate was steep. Even now, when the mortality rate has declined, due to the ubiquitous application of endoscopic and percutaneous transhepatic biliary drainage, acute cholangitis can be fatal unless it is treated in a timely way. Although endoscopic drainage is less invasive than other drainage techniques and should be considered as the drainage technique of fi rst choice (level 2b), 4 details of its procedures remain controversial. This article outlines various biliary drainage techniques, especially in regard to endoscopic procedures.

# Abstract
Biliary decompression and drainage done in a timely manner is the cornerstone of acute cholangitis treatment. The mortality rate of acute cholangitis was extremely high when no interventional procedures, other than open drainage, were available. At present, endoscopic drainage is the procedure of fi rst choice, in view of its safety and effectiveness. In patients with severe (grade III) disease, defi ned according to the severity assessment criteria in the Guidelines, biliary drainage should be done promptly with respiration management, while patients with moderate (grade II) disease also need to undergo drainage promptly with close monitoring of their responses to the primary care. For endoscopic drainage, endoscopic nasobiliary drainage (ENBD) or stent placement procedures are performed. Randomized controlled trials (RCTs) have reported no difference in the drainage effect of these two procedures, but case-series studies have indicated the frequent occurrence of hemorrhage associated with endoscopic sphincterotomy (EST), and complications such as pancreatitis. Although the usefulness of percutaneous transhepatic drainage is supported by the case-series studies, its lower success rate and higher complication rates makes it a secondoption procedure.

## Techniques of endoscopic biliary drainage
Transpapillary biliary drainage for acute cholangitis is based on selective cannulation into the bile duct with endoscopic retrograde cholangiopancreatography (ERCP). However, as these drainage procedures are different in regard to: (i) the additional application of endoscopic sphincterotomy (EST), and (ii) the selection of either endoscopic nasobiliary drainage (ENBD) or stent placement, they are explained below in detail.

## Ercp
ERCP is a procedure to insert a contrast test catheter into the papilla, using a duodenal scope to visualize the bile duct. To secure a drainage route (for ENBD or stent placement), successful selective cannulation into the bile duct is essential. If cannulation deep into the bile duct is diffi cult, replacement of the catheter, the use of a guidewire, and precutting (by EST, explained below), are necessary. If the cannulation into the bile duct fails, other drainage, such as percutaneous transhepatic biliary drainage, is necessary. Also, the quantity of con- and the incidence of acute pancreatitis, known to become fatal once it progresses severely, depends on the skills of the endoscopist (level 1b, level 4) 6,7 [fig_ref] Table 1: Complications caused by EST [/fig_ref].

## Precutting techniques
Precutting is an incision of the papilla to facilitate cannulation into the bile duct when selective cannulation is impossible. EST can be completed by a common procedure after selective cannulation into the bile duct becomes possible. The method using a needle-type sphincterotome for probing in the opening of the bile duct is common , but there is also a method to incise the tips of the bile duct with a push-type or shark's fi n-type sphincterotome. The types of sphincterotome and the detailed procedures used differ depending on the medical institution. It is also known that precutting is likely to cause serious complications such as acute pancreatitis and perforation, and therefore it can be used only by skilled endoscopic surgeons (level 1b, level 4). [bib_ref] Complications of endoscopic biliary sphincterotomy, Freeman [/bib_ref] [bib_ref] Endoscopic sphincterotomy complications and their management : an attempt at consensus, Cotton [/bib_ref] Signifi cance of EST in endoscopic biliary drainage According to some case-series studies, the reasons that additional EST are not necessary in acute cholangitis are that:
(i) The application of additional EST to drainage produces no difference in effect

## Est

## Standard techniques
EST is a procedure used widely not only in the treatment of choledocholithiasis but also as a drainage procedure for malignant biliary obstruction. Sphincterotomes used for incision include several types such as: the pull-type , push-type [fig_ref] Figure 2: Push-type sphincterotome [/fig_ref] , needle type [fig_ref] Figure 3: Needle-type sphincterotome [/fig_ref] and, the shark's fi n-type, and others, each of which has a different length of exposed wire and different tip shape. The most common sphincterotome is the pull type. The pull-type sphincterotome is useful when ERCP is diffi cult, because the direction of the tip of the sphincterotome can be changed by adjusting the tension of the blade . The push-type and needle-type are used for diffi cult cases. A common EST technique is to perform a highfrequency electric surgical incision of the duodenal papilla, using a sphincterotome selectively cannulated in the bile duct (Figs. 4 and 5). In EST for drainage purposes, unlike that for stone removal, only a limited incision is necessary (level 4).Acute pancreatitis and cholangitis are common complications caused by EST, (ii) the additional EST causes complications such as hemorrhage.
Acute cholangitis is one of the risk factors for post-EST hemorrhage (level 1b), [bib_ref] Complications of endoscopic biliary sphincterotomy, Freeman [/bib_ref] and the use of EST in patients with severe (grade III) disease complicated by coagulopathy should be avoided. On the other hand, EST has advantages such as:
(a) Not only drainage but also single-stage lithotomy can be employed in patients with choledocholithiasis (not complicated by severe cholangitis) (b) Precutting can ensure a drainage route into the bile duct in patients in whom selective cannulation is diffi cult.
Endoscopic drainage employed for acute cholangitis does not always require EST (level 4). [bib_ref] The benefi ts of endoscopic nasobiliary drainage without sphincterotomy for acute cholangitis, Sugiyama [/bib_ref] [bib_ref] Does the addition of endoscopic sphincterotomy to stent insertion improve drainage of..., Hui [/bib_ref] However, precutting may be indispensable in performing drainage in some patients with impacted stones in the papilla of Vater, and whether or not additional EST should be conducted depends on the condition of the patient and the skills of the endoscopist. In the Guidelines, readers are reminded to be cautious when additional EST is employed.

## Endoscopic biliary drainage (ebd)
Endoscopic drainage includes not only endoscopic biliary drainage (EBD) but also EST without stent insertion, which means that calculus removal can be performed with only one endoscopic procedure. EBD is of two types endoscopic nasobiliary drainage (ENBD; external drainage) and stent placement (internal drainage). No difference between these two methods was proven by past RCTs (level 2b), [bib_ref] Biliary decompression by nasobiliary catheter or biliary stent in acute suppurative cholangitis:..., Lee [/bib_ref] [bib_ref] Endoscopic biliary drainage by nasobiliary drain or by stent placement in patients..., Sharma [/bib_ref] and the Guidelines suggest that either drainage procedure may be chosen. Internal drainage does, however, confer less electrolyte disturbance as there is no external loss of bile and its contents.

## Endoscopic nasobiliary drainage (enbd)
ENBD is an external drainage procedure done by placing a 5-to 7-Fr tube, using a guidewire technique, after selective cannulation into the bile duct, and it is used to complete nasobiliary drainage . ENBD has these advantages:
(i) No additional EST is required (ii) Clogging in the tube (external drain) can be washed out (iii) Bile cultures can be done However, because of the patient's discomfort from the transnasal tube placement, self-extraction and dislocation of the tube are likely to occur, especially in elderly patients. Loss of electrolytes and fl uid as well as collapse of tubes by twisting, may also occur.
Additional EST must be considered for the removal of concomitant bile duct stones and viscous bile or pus in patients with suppurative cholangitis. Plastic stent placement Plastic stent placement is an internal drainage procedure done to place a 7-to 10-Fr plastic stent in the bile duct, using a guidewire after selective cannulation into the bile duct (Figs. 11 and 12). There are two different stent shapes, a straight type with fl aps on both sides, and a pig tail type, to prevent dislocation [fig_ref] Figure 3: Needle-type sphincterotome [/fig_ref]. Absence of discomfort and no loss of electrolytes or fl uid relative to transnasal biliary drainage are advantages. However, as it cannot be known in real time whether the stent is patent, there is a risk of dislodgement or clogging of the stent. The other disadvantage is that when a stent with a diameter larger than 7-Fr is inserted, EST is necessary.
EST without stent insertion EST without stent insertion can be used to remove bile duct calculi as well as for drainage. This method can shorten the hospital stay because both calculus removal and drainage are completed with only one endoscopic procedure. However, caution should be exercised, with monitoring for cholangitis due to residual calculi or sludge. . Plastic stent placement (7-Fr straight plastic stent). a An endoscopic catheter is cannulated into the bile duct. b A guidewire is passed through the catheter into the bile duct. c The catheter is withdrawn. d A plastic stent is inserted along the guidewire into the bile duct by using a pusher tube. e The guidewire is removed while pushing on the pusher tube (care should be taken not to deviate from the bile duct). f The endoscope is removed, leaving the plastic stent in place

## Techniques of percutaneous transhepatic cholangial drainage (ptcd)
Though there are no studies comparing percutaneous transhepatic cholangial drainage PTCD; also known as percutaneous transhepatic biliary drainage; PTBD, and endoscopic drainage, PTCD should applied, in principle, to those patients who cannot undergo endoscopic drainage because of the possible serious complications of PTCD, including intraperitoneal hemorrhage and biliary peritonitis (level 4) [fig_ref] Table 1: Complications caused by EST [/fig_ref] and a long hospital stay. A propensity for hemorrhage is a relative contraindication, but if there is no other lifesaving method, PTCD is indicated. In view of this, the Guidelines give recommendation grades A and B to endoscopic drainage and PTCD, respectively. Before the widespread application of ultrasonography, a procedure to puncture the bile duct under fl uoroscopic control following PCTD (level 4) 13 was employed. But because it caused complications in many cases, puncture under ultrasonography is more common now (level 4). [bib_ref] Technique and management of percutaneous transhepatic cholangial drainage for treating an obstructive..., Takada [/bib_ref] After ultrasound-guided transhepatic puncture of the intrahepatic bile duct is done with an 18-to 22-G needle to confi rm backfl ow of bile, a 7-to 10-Fr catheter is placed in the bile duct under fl uoroscopic control, using a guidewire (Seldinger technique). As a guidewire cannot be inserted directly when a 22-G needle is used, it is necessary to insert the guide-wire after dilating the bile duct with an elastic needle, using a steel wire. This procedure, requiring another step, is a little complicated (see , but puncture with a small-gauge (22-G) needle is safer in those patients without biliary dilatation. According to the Quality Improvement Guidelines produced by American radiologists, the success rates of drainage are 95% in patients with biliary dilatation and 70% in those without biliary dilatation (level 4). [bib_ref] Percutaneous transhepatic cholangial drainage: direct approach under fl uoroscopic control, Takada [/bib_ref] 

## Techniques of open drainage
Patients with acute cholangitis are preferentially treated with a noninvasive drainage procedure such as endoscopic drainage and PTCD, and only a few undergo open drainage. However, open drainage may be indicated for patients who cannot undergo such noninvasive drainage procedures, for anatomical and structural reasons, including patients after Roux-en-Y choledochojejunostomy with a propensity for hemorrhage. In open drainage, the goal is to decompress the biliary system. Simple procedures such as T-tube placement without choledocholithotomy should be recommended, because prolonged operations should be avoided in such ill patients (level 4). [bib_ref] Early operation for acute biliary tract stone disease, Saltzstein [/bib_ref] 
[fig] Fig: 1a,b. Pull-type sphincterotome. a A pull-type sphincterotome is shown; it has various applications, and is useful for opening the bile duct. b The direction of the tip of the blade [/fig]
[table] Table 1: Complications caused by EST [/table]
[table] Table 2: Serious complications caused by PTCD 12 PTCD or PTBD [biliary]) procedure. a Under ultrasound guidance, the intrahepatic bile duct is punctured by the use of a hollow needle (external cylinder with a mandolin). b Only the mandolin is removed, and the cylinder remains. After confi rming the backfl ow of bile, bile duct imaging is performed. c A steel wire is inserted through the cylinder. d After confi rming suffi cient insertion of the wire into the bile duct, the hollow needle (cylinder with the mandolin) is removed. e An elastic needle is passed over the wire. f Backfl ow of bile is confi rmed after withdrawing the inner tube from the elastic needle. A guidewire is then inserted. g A PTCD (or PTBD) tube is passed over the guidewire. h The guidewire is withdrawn and the tube is left and fi xed in place [/table]