Su1543 TREATMENT OF MALIGNANT HILAR BILIARY OBSTRUCTION IN CHOLANGIOCARCINOMA – A META-ANALYTIC COMPARISON OF ENDOSCOPIC STENT-IN-STENT VERSUS SIDE-BY-SIDE INSERTION OF SELF-EXPANDING METAL STENTS

Abstract

Biliary self-expanding metal stents (SEMS) are the standard of care for the management of malignant hilar biliary obstruction (MHBO) in the setting of cholangiocarcinoma (CCA). Multiple endoscopic techniques for SEMS insertion for MHBO in CCA exist, but the clinical utility of differing modalities is not well-studied. A comprehensive literature search was performed of Medline(Ovid) and Embase from inception-July 2019. All studies were screened by two authors to identify studies reporting the safety and efficacy of hilar SEMS insertion in a Y-configuration stent-in-stent (SIS) or side-by-side (SBS) fashion. Pooled data was reported as proportions or standardized mean difference (SMD) with thier respective 95% confidence interval (CI). Screening of 3553 studies yielded 16 studies reporting the utility of SIS or SBS SEMS insertion in the setting of cholangiocarcinoma, enrolling a total of 482 patients. Only one study directly compared SBS to SIS technique. Overall, 36% (23-51%) and 40% of SIS and SBS patients had Bismuth IV disease (Table 1). The mean pre-stent total bilirubin (TB) was 8.69 mg/dL (6.42-10.96). SIS and SBS were technically successful in 98% (72-100%) and 93% (84-97%) of cases, with mean follow-up of 233.44 days (189.82-277.07). Clinical success for SIS and SBS technique were 90% (66-98%) and 88% (81-94%). Overall, adverse event rate was 47% (35%-59%) and 50% (35-65%) for SIS and SBS technique. The mean post-stent TB was 1.49 mg/dL (0.97-2.01), with an SMD of 1.56 (1.02-2.01). Recurrent biliary obstruction (RBO) rate was 42% for both SIS (31-53%) and SBS (29-56) techniques, with a mean time to RBO of 167.09 days (68.22-265.96) and 164.29 days (112.68-215.80) for SIS and SBS techniques. Tumor ingrowth rate was 32% (24-41%) with SIS and 26% (22-37%) with SBS technique. Biliary sludge was found in 6% (2-18%) and 14% (5-33%) of SIS and SBS cases. Cholecystitis developed in 5% (2-10%) and 9% (4-20%) of SIS and SBS cases. Liver abscess formation was reported in 5% (3-9%) and 8% (4-16%) of SIS and SBS cases. Cholangitis occurred in 10% (4-25%) and 16% (8-27%) of SIS and SBS cases. Endoscopic reintervention was required in 43% (35-51%) and 36% (20-55%) of SIS and SBS cases, whereas 7% (3-16) and 20% (8-41%) of SIS and SBS cases required PTBD. The mean duration of stent patency for SIS and SBS techniques was 175.88 days (127.12-201.97) and 102.28 days (55.66-148.89), respectively. Both SIS and SBS SEMS insertion are highly efficacious in relieving MHBO from CCA. SIS technique had longer stent patency compared to SBS stent placement. Additionally, 20% of SBS patients required PTBD. These findings suggest SIS may be superior to SBS placement using current techniques. However, well-designed, head-to-head studies are needed to devise stronger recommendations.