Biliary Stenting 

Updated: Sep 30, 2019
Author: Philip L Johnson, MD; Chief Editor: Kyung J Cho, MD, FACR, FSIR 

Overview

Background

Over the past few decades, biliary interventions have evolved a great deal. Opacification of the biliary system was first reported in 1921 with direct puncture of the gallbladder. Subsequent reports described direct percutaneous biliary puncture. The technique was revolutionized in 1960s with the introduction of fine-gauge (22- to 23-gauge) needles.

During the 1970s, percutaneous biliary drainage (PBD) for obstructive jaundice and percutaneous treatment of stone disease was introduced. Percutaneous cholecystostomy was first described in the 1980s. With the advent of metallic and plastic internal stents, further applications in the treatment of biliary diseases were developed.[1]

Current percutaneous biliary interventions include percutaneous transhepatic cholangiography (PTC) and biliary drainage to manage benign[2] and malignant obstruction and percutaneous cholecystostomy.[3] Percutaneous treatment of biliary stone disease, with or without choledochoscopy, is still performed in selected cases. Other applications include cholangioplasty for biliary strictures, biopsy of the biliary duct, and management of complications from laparoscopic cholecystectomy and liver transplantation.

Endoscopic ultrasonography (EUS)-guided biliary interventions are the subject of increasing interest (eg, in patients with unresectable distal biliary malignant obstruction who failed endoscopic retrograde cholangiography [ERCP]).[4]

This article outlines the procedure for biliary stenting. For descriptions of other biliary interventions, see Percutaneous Cholecystostomy, Percutaneous Cholangiography, and Percutaneous Biliary Drainage.

Indications

The most common indication for biliary stenting is for treatment of obstructive jaundice from either benign or malignant causes.[5, 6] On occasion, stents are placed for management of bile leaks. Stents are made of either plastic or metal, and they are placed to provide internal drainage, eliminating the need for an external catheter.

The major advantage plastic stents have over metallic stents is that they can be removed and replaced if necessary. Metallic stents, on the other hand, are generally permanent, but they have the advantage of a larger lumen and longer patency. This advantage is achieved by a design that enables placement with a relatively small delivery device (7 French) that contains the constrained stent by an outer sheath. Once the stent is positioned, the outer sheath is retracted, allowing the stent to expand.

Self-expanding metallic stents placed in the biliary tree have a luminal diameter of 10 mm, which is significantly larger than plastic stents, which are typically 2-4 mm in luminal diameter. Nevertheless, the patency of metallic stents is only 60-70% at 6 months, and nearly all are occluded by 1 year. Therefore, the use of permanent metallic stents to treat benign biliary obstruction is not recommended.

The choice of plastic or self-expanding metallic stents depends on the etiology of the obstruction. In patients with malignant disease and a life expectancy less than 6-12 months, metallic stents are more cost-effective and are associated with shorter hospital stays and fewer reinterventions.[7] Therefore, the use of metallic stents for biliary obstruction is reserved for patients with inoperable malignant biliary obstruction and a life expectancy less than 6-12 months.

Covered self-expanding metal stents are available that have a thin layer of material such as polytetrafluoroethylene (PTFE) on the exterior, which improves patency by preventing tumor ingrowth. These stents can be repositioned or removed with the use of a snare or forceps.

Contraindications

There are only a few contraindications for percutaneous biliary stenting in appropriately selected patients, and these are primarily related to bleeding. Therefore, any bleeding disorders should be corrected prior to the procedure.

Ascites is a contraindication because it limits tamponade of blood or bile. Therefore, a paracentesis should be performed immediately prior to the procedure.

It is essential that patients are able to hold still and cooperate for the procedure. Most procedures are performed under conscious sedation, but an uncooperative patient may require general anesthesia.

Outcomes

In a prospective study by Lakhtakia et al, 118 patients with chronic pancreatitis (CP) and a benign biliary stricture (BBS) were treated with temporary placement of a single fully covered self-expanding metal stent (FCSEMS) with scheduled removal at 10-12 months and followed for 5 years.[8]  The probability of remaining stent-free at a median of 58 months was 61.6%; in the 94 patients whose BBSs resolved at the end of FCSEMS indwell, the probability of remaining stent-free 5 years later was 77.4% Serious stent-related adverse events occurred in 22.9% of patients; all resolved with medical therapy or repeated endoscopy. Severe CP and longer stricture length were predictors of stricture recurrence.

 

Periprocedural Care

Equipment

A dedicated procedure room with a C-arm fluoroscopy unit equipped with pulsed fluoroscopy, beam collimation, and lead shields to limit the radiation dose is essential. Radiation monitoring badges should be worn at all times. The procedure room should also be furnished with modern anesthesiology, electrocardiography (ECG), and oxygen saturation monitoring equipment.

The procedure is performed in a sterile environment, and requirements include hat, mask, sterile gowns, sterile gloves, general sterile procedure pack, and sterile towels. Nonionic water-soluble contrast agents are employed. Procedural equipment includes devices required for initial percutaneous biliary access and biliary stent placement.

Patient Preparation

Anesthesia

Percutaneous biliary procedures can be associated with significant pain, and there is wide variation in patient tolerance to pain and ability to cooperate. Therefore, a carefully considered plan for analgesia and sedation is mandatory. The patient is carefully evaluated for medical comorbidities, NPO (nil per os) status, prior history of anesthesia, tolerance to prior procedures, and the complexity of the planned procedure.

The American Society of Anesthesiologists (ASA) physical classification system is a useful and simple tool for stratifying patient risk. For most patients, conscious sedation is the most appropriate level of analgesia and sedation, balancing safety and comfort.

During conscious sedation, patients are able to maintain purposeful response to verbal and tactile stimulation, ventilate spontaneously, and maintain cardiovascular function. A combination of a fast-acting opioid (eg, fentanyl) for pain and a fast-acting benzodiazepine (eg, midazolam) for anxiolysis is typical. It is important to understand the synergistic effect these drugs have when used in combination and to realize the wide variation in patient sensitivity.

Careful titration and monitoring are essential. Appropriately trained personnel, hemodynamic and oxygen monitoring equipment, and immediate access to drugs and resuscitation equipment are imperative.

Positioning

Percutaneous biliary procedures are performed with the patient in a supine position. The use of a rotating C-arm conveniently obviates the need to rotate the patient for additional oblique views.

 

Technique

Placement of Plastic and Metallic Biliary Stents

The stent is usually placed at an interval of a few days after percutaneous biliary drainage (PBD), though in cases of uncomplicated percutaneous transhepatic cholangiography (PTC), the stent procedure can be accomplished at the same time.

An introducer sheath is passed into the biliary system over a stiff wire. The stent delivery system is then advanced over the wire, and the stent is deployed. Balloon dilation is occasionally needed to achieve adequate expansion. In cases of hilar malignancy that causes obstruction of both hepatic ducts, bilateral stents may be needed.[9] (See the videos below.)

This video, captured via endoscopic retrograde cholangiopancreatography, shows the placement of a biliary stent into the common bile duct. Video courtesy of Dawn Sears, MD, and Dan C. Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.
This video, captured via endoscopic retrograde cholangiopancreatography, shows the brushing of a common bile duct stricture using a biliary brush. This is done to collect cells that can then be analyzed to rule out malignancy. Video courtesy of Dawn Sears, MD, and Dan C. Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.
This video, captured via endoscopic retrograde cholangiopancreatography, shows the insertion of a biliary stent into the common bile duct. Video courtesy of Dawn Sears, MD, and Dan C. Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.
This video, captured via endoscopic retrograde cholangiopancreatography, shows the advancement of a biliary cannulation catheter over a guidewire into the common bile duct. Video courtesy of Dawn Sears, MD, and Dan C. Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.
This video, captured via endoscopic retrograde cholangiopancreatography, shows the advancement of a biliary stent into the common bile duct. Video courtesy of Dawn Sears, MD, and Dan C. Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.
This video, captured via endoscopic retrograde cholangiopancreatography, shows successful insertion, advancement, and deployment of a biliary stent into the common bile duct. Bile is seeing draining from the stent into the duodenum. Video courtesy of Dawn Sears, MD, and Dan C. Cohen, MD, Division of Gastroenterology, Scott & White Healthcare.

Plastic vs metallic stents

Internal biliary stents are either plastic or metallic, and various types of each kind are available.

Internal biliary stents have several advantages.[10]  An external tube can be uncomfortable and have a psychological disadvantage (especially in cases of malignant obstruction). An internal stent prevents the problems related to external catheters (eg, pericatheter leakage of bile and the need for daily flushing). Disadvantages include having to perform endoscopic retrograde cholangiopancreatography (ERCP; see the videos above) or new PTC procedures to obtain access in case of stent obstruction.

Better patency rates are reported with metallic than with plastic stents in cases of malignant obstruction, though no effect on survival is noted. Plastic internal stents are cheapest but reportedly prone to migration. Various types of plastic stents in use include the Carey-Coons stent (Percuflex; Meditech/Boston Scientific, Marlborough, MA) and silicone stents (Malecot; Cook Medical, Bloomington, IN).

Metallic stents have not been commonly used in the treatment of benign disease, because studies showed poor long-term patency rates. Gabelman et al reported a patency rate of only 25% at 36 months when metallic stents were used to treat benign obstruction.[11] In another study, Lopez et al found that two thirds of patients had poor clinical results and that one half of these required major surgical intervention.[12]  However, there is increasing interest in using covered metallic stents in the setting of benign disease.[13, 14]

The Gianturco-Rosch Z stent (Cook Medical, Bloomington, IN), a metallic stent, has been used in benign strictures but has not been generally recommended for primary treatment. Limited applications may include the treatment of patients who are poor surgical candidates or of those in whom surgical treatment fails. Most postoperative strictures are treated surgically, though endoscopic and (less commonly) percutaneous placement of nonmetallic stents has increasingly been used in the past few years.[15, 16]

In cases of malignant obstruction, stents are placed as a palliative measure only if the tumor is unresectable (see the image below). Various stents are approved for use in the biliary system, including self-expanding and balloon-mounted stents. Self-expanding stents include the Wallstent (Boston Scientific, Natick, MA), the Luminex stent (Bard, Tempe, AZ), and the Smartstent (Cordis Endovascular, Miami, FL).[17]

Self-expanding stent placed in the common bile duc Self-expanding stent placed in the common bile duct (CBD) in a patient with an unresectable pancreatic tumor.

Kaskarelis et al reported a 98% technical success rate in the treatment of malignant biliary obstruction with metallic stents[18] ; the stent occlusion rate was 18% at a mean interval of 288 days. Lee et al showed a 50-week patency rate of 53%.[19]

There is interest in the use of paclitaxel-eluting biliary metal stents. A prospective radomized study from South Korea compared the efficacy and safety of a paclitaxel-eluting biliary metal stent incorporating sodium caprate (MSCPM-III; n = 54) with those of a covered metal stent (CMS; n = 51) in patients with malignant biliary obstructions.[20]  Time to recurrent biliary obstruction (RBO) and survival time were comparable in the two groups; however, tumor size at 2 months after stent insertion was significantly decreased in patients in the MSCPM-III group with bile duct cancers or those who experienced stent migration. Complication rates were acceptable in both groups.

Additional considerations

There are some data from observational studies to suggest that the use of radiofrequency ablation (RFA) as an adjunct to biliary stenting is safe and may be associated with improved stent patency; it may also be associated with improved survival in these patients.[21]

Endoscopic ultrasonography (EUS)-guided biliary interventions are the subject of increasing interest (eg, in patients with unresectable distal biliary malignant obstruction who failed endoscopic retrograde cholangiography [ERCP]).[4]

Complications

Recurrent jaundice or cholangitis due to obstruction of the stents is the major limitation of biliary stenting. The main cause of obstruction is biliary sludge and tissue hyperplasia in the lumen of the stent, which necessitates removal and replacement every 2-3 months, and sometimes more frequently. In the case of malignant disease, tumor ingrowth through the stent and proximal and distal tumor overgrowth can also cause obstruction.

Covered stents are being investigated to overcome the problem of tumor ingrowth. Two studies of stents covered with expanded polytetrafluoroethylene–fluorinated ethylene propylene (ePTFE-FEP) reported 12-month patency rates higher than 75%.

In a multicenter retrospective study of 315 consecutive patients with distal malignant biliary strictures who underwent ERCP and placement of (a) a fully covered self-expanding metal stent, (b) an uncovered self-expanding metal stent, or (c) a plastic stent as first-line treatment, Sampaziotis et al found that the fully covered metal stents remained patent longer and caused fewer complications than either of the other types, though they were also associated with a higher rate of pancreatitis than the uncovered metal stents were.[22]

Sugawara et al reported a 24.2% rate of acute pancreatitis necessitating pharmacologic treatment in patients who underwent percutaneous placement of metallic biliary stents across the papilla of Vater for malignant biliary stricture.[23]  In a retrospective study of 143 patients with unresectable pancreatic cancer who underwent percutaneous metallic biliary stent insertion, Kim et al found acute pancreatitis to be a relatively rare complication after this procedure in this population, and they were not able to identify any significant risk factors.[24]