Biodegradable Stents Versus Plastic Stents for Treatment of Biliary Anastomotic Strictures in Liver Transplant RecipIents

Liver transplantation (LT) is nowadays a standard treatment method of end-stage liver disease, primary liver cancer and acute liver failure.

Biliary complications (BCs) following liver transplantation are the leading source of morbidity and liver graft failure and are associated with up to 10% mortality rate. The incidence of BCs remains high, being reported in 10-25% in cadaveric donors (DDLT) and in more than 30% in living donor liver transplantations (LDLT), despite improved both preoperative and postoperative care and enhanced surgical technique. Anastomotic biliary strictures (ABS) are together with bile leaks the most common biliary complication occurring any time after LT, but being primarily found within the first year LT. The incidence ranges between 5-15% in DDLT and 13-36% in LDLT. Anastomotic strictures are typically present at the site of anastomosis, tend to be short, single and constitute up to 86% of all biliary strictures. The clinical presentation can differ from patients being asymptomatic to some presenting with symptoms of biliary obstruction (jaundice, fever, chills, nausea, abdominal pain). The clinical picture can resemble also other conditions and it is important to differentiate biliary complication (BC) from other similarly presenting entities such as acute rejection, hepatic artery thrombosis, recurrence of primary sclerosing cholangitis or acute hepatitis). The gold standard for diagnosis of BCs is MRCP with reported sensitivity and specificity of up to 95%.

The first line therapy of BCs is endoscopic retrograde cholangiopancreatography (ERCP), in case of failure or altered anatomy percutaneous approach may be indicated. If both methods fail surgery is required. ERCP is an invasive endoscopic technique used primarily for therapy of pancreatobiliary tract. It is associated with risk of complications such as acute pancreatitis, bleeding, acute cholangitis or in rare cases perforation.

There are two standard approaches in the treatment of anastomotic biliary strictures, similarly to the treatment of other benign strictures of the bile duct. First, the use of multiple plastic stents (MPS) requiring their repeated endoscopic exchanges may be employed. Alternatively, a single self-expandable metal stent is placed for a longer period of time.

The endoscopic therapy of anastomotic strictures using multiple plastic stents typically requires multiple stent exchanges, starting with placing a single stent and adding multiple stents during further sessions. The sessions are scheduled every 1 to 3 months. The resolution of the anastomotic stricture is usually achieved in 12months, exposing the patient typically to 3-4 ERCP procedures. MPS technique was firstly described and put in practice in a single center study by Costamagna et al. with clinical success rate in 89%. After that many other studies have been published regarding this topic, including a meta-analysis, where the resolution rate of strictures were reported in 94%-100%. Finally in 2017 by Koksa et al. was reported a review demonstrating that in patients with more than 12 months of stenting, with higher total number of stents and number of stents inserted per session, a higher resolution rate and a lower recurrence rate were showed. Alternative option for the endoscopic treatment of ABS is the use of a single fully covered self-expandable metal stent (FC-SEMS), in studies showing similar rates of ABS resolution compared to MPS method with the advantage of not repeating ERCP to place multiple stents, although with higher risk of migration.