Benign Biliary Strictures

Clinical Features and Diagnosis

Approximately 80% of patients with postoperative BBS present within 6 to 12 months after surgery with symptoms of jaundice, pruritus, abdominal pain, alterations of liver function tests, and recurrent cholangitis. It is very important to promptly recognize these symptoms, as long-standing cholestasis can lead to secondary biliary cirrhosis. About 10% of BBS patients present within 1 week of surgery, and the condition may be associated with biliary leaks.

ERCP has primarily a therapeutic role in BBS. Nevertheless, the diagnostic (cholangiographic) phase of ERCP is essential to determine the morphologic type of the stricture. The classification of Bismuth and Lazorthes is a morphologic classification developed before the advent of laparoscopy. This classification was intended to guide surgical repair of postoperative BBS. Today it is widely used to classify lesions according to the cholangiographic appearance and classifies BBS into five types : type 1, low common hepatic duct (CHD) or bile duct (CHD >2 cm); type 2, mid-CHD (CHD <2 cm); type 3, hilar stricture; type 4, involvement of the main hilar confluence (right and left hepatic ducts separated); type 5, involvement of a right hepatic branch alone or with common duct.

The clinical presentation of biliary strictures is somewhat different in patients with CP. In a retrospective review of 78 patients with CP, overt jaundice was found in only a minority of patients. No relationship was found between features of the common bile duct (CBD) and severity of pancreatitis or disease duration. Up to one-third of patients with advanced CP develop symptomatic biliary stenosis. Biliary obstruction caused by compression from an edematous pancreatic head or a pseudocyst usually resolves when the inflammation subsides or after resolution of the pseudocyst. However, obstruction caused by a fibrotic stricture does not resolve spontaneously and requires therapeutic intervention.

The preferred noninvasive method for diagnostic cholangiography in BBS is magnetic resonance cholangiopancreatography (MRCP). MRCP is extremely useful in providing a roadmap for endoscopic drainage. MRCP is also used to distinguish between anastomotic (extrahepatic) and ischemic (intrahepatic) strictures after LT.

Ruling out underlying malignancy is especially important in the presence of BBS in patients with underlying CP and those with PSC. MRCP, computed tomography scan, endoscopic ultrasonography with fine-needle aspiration (EUS/FNA), and ERCP with biliary brush cytology and/or intraductal biopsies are the first-line diagnostic modalities in these situations. EUS/FNA is widely used in ruling out malignancy in patients with mass-forming CP. This method can also be used for rendezvous EUS/ERCP procedures in case of failed transpapillary access to the bile ducts (see Chapter 32 ). Cholangioscopy with targeted biopsy (see Chapter 27 ) is useful in selected cases where other diagnostic methods have failed to confirm malignancy, especially in patients with autoimmune (IgG4-related) cholangiopathy and PSC.

Endoscopic Technique

Endoscopic treatment of BBS involves two technical steps: (1) negotiating the stricture and (2) dilating the stricture. Negotiating the stricture requires continuity of the CBD. In cases of complete transection or ligation of the CBD, a guidewire cannot be passed across the lesion and thus endotherapy alone is not feasible. Although surgical reconstruction is indicated in complete transection or ligation of the CBD, in some reports a combined percutaneous/endoscopic technique has been adopted, aiming to bring together the two stumps of a transected bile duct.

After deep bile duct access, a cholangiogram is performed to determine the type and features of the BBS. Performing a complete biliary sphincterotomy is important because repeated stent exchanges and insertion of multiple stents are required in most cases.

BBS are generally short, asymmetric, and rich in fibrous tissue, which makes them more difficult to negotiate compared with neoplastic strictures. These strictures are more complex and negotiation is more difficult when the hepatic hilum is involved. It is therefore often necessary to use thin hydrophilic guidewires (0.021-inch or 0.018-inch diameter) with a straight or curved (J-shaped) tip to traverse the stricture. Guidewire manipulation requires patience, skill, and optimal fluoroscopic imaging. Forceful maneuvers may create false passages and should be avoided. Using an inflated stone retrieval balloon positioned just distal to the stricture and applying downward traction results in stretching the bile duct and modifying the axis of the guidewire and stricture. Steerable catheters or papillotomes may also be used to negotiate the stricture. Once the stricture is traversed, the hydrophilic guidewire can be exchanged for a stiffer wire to facilitate dilation.

Stricture dilation has two objectives: (1) to reopen the CBD to achieve bile drainage and (2) to keep the stenosis open and avoid restricturing.

Insertion of the guidewire through the stricture is followed by placement of a 5-Fr or 6-Fr catheter over the guidewire. Dilation can be done mechanically or with balloons. Mechanical dilation is usually done with dilation catheters (e.g., 6- to 9.5-Fr Cunningham-Cotton sleeve; Cook Endoscopy, Winston-Salem, NC) to test the caliber of the stricture before attempting stent insertion. Hydrostatic balloon dilation is generally done with 4-mm, 6-mm, and 8-mm low-profile balloons, particularly in cases where the stricture is not amenable to mechanical dilation. Balloon dilation is usually performed to a size 1 to 2 mm larger than the downstream bile duct diameter. Although immediately effective, endoscopic and percutaneous balloon dilation alone, whether in a single session or multiple sessions, is considered inadequate and associated with a high restenosis rate (up to 47%).

Stent placement in addition to dilation maintains stricture patency for a prolonged period to allow scar remodeling and consolidation. When mechanical and/or balloon dilation is unsuccessful in allowing large-bore stent placement, leaving a 5-Fr or 6-Fr nasobiliary drainage tube in situ for 24 to 48 hours may increase the chances of subsequent endoscopic stent placement. Alternatively, screw-type stent extractors (Soehendra stent extractor; Cook Endoscopy) and angioplasty balloons mounted on 3-Fr catheters can allow for passage of balloon dilators mounted on 5-Fr catheters and subsequent stent placement.

Placement of a single plastic stent leads to unsatisfactory long-term outcomes. Currently, the most effective method for calibration of postoperative BBS is the temporary simultaneous placement of a progressive number of plastic stents, over a period of 1 year (with stent exchanges every 3 to 4 months). This “aggressive multistenting strategy” is highly effective but requires multiple ERCP sessions and is dependent on patient compliance ( Fig. 43.1 ).

Removable fully covered self-expanding metal stents (SEMS) have emerged as an alternative to multiple plastic stents to avoid multiple ERCP sessions with need for upsizing and plastic stent exchanges. When SEMS are used, theoretically only two ERCP procedures are needed: one for stent placement and one for removal. Placement of uncovered SEMS should be avoided in all types of BBS, because stent imbedding and ingrowth of reactive tissue through the mesh of the stent makes them irretrievable.

Candidates for fully covered SEMS should be selected very carefully. Bismuth type I postcholecystectomy strictures, selected cases of biliary anastomotic strictures in LT patients, and CP-related BBS are the best candidates. Placing fully covered SEMS in strictures of the hepatic hilum should be avoided, mainly because of the risk of impaction and occlusion of intrahepatic branches that can lead to sepsis.

Biodegradable biliary stents could be used in the future for endoscopic management of BBS. The potential advantages of these stents are that only one ERCP session is needed for placement and removal is unnecessary. Different biodegradable materials have been tested to date (polylactide, polycaprolactone, and polydioxanone) but are still under investigation. The main disadvantages of these stents are that the expansive radial force decreases with the degradation of the stent and there is a potential inflammatory foreign body reaction leading to hyperplasia. Additionally, there are scarce data to support their use. Currently, the only data available in humans were published recently by Siiki et al. The authors placed two biodegradable stents in two patients with excellent stricture resolution at 6 months, with biodegradability confirmed on magnetic resonance imaging. Before this report, the efficacy of biodegradable stents had been proven only in animal models. This promising new treatment requires further investigation.

Outcomes of Endotherapy