Retrospective comparative study of new slim‐delivery and conventional large‐cell stents for stent‐in‐stent methods for hilar malignant biliary obstruction

Abstract

ObjectivesEndoscopic management of unresectable hilar malignant biliary obstruction (HMBO) is technically challenging, and effectiveness of stent‐in‐stent using large‐cell, metal stents was reported. A new, large‐cell stent with a 6F tapered delivery system was recently developed. The aim of this study was to compare clinical outcomes of slim‐delivery and conventional large‐cell stents.MethodsThis was a multicenter retrospective comparative study of stent‐in‐stent methods using slim‐delivery stents (Niti‐S Large Cell SR Slim Delivery [LC slim‐delivery]) and conventional stents (Niti‐S large‐cell D‐type; LCD) for unresectable HMBO.ResultsEighty‐three patients with HMBO were included; 31 LC slim‐delivery and 52 LCD. Overall technical and clinical success rates were 100% and 90% in LC slim‐delivery group and 98% and 88% in LCD group. Use of the LC slim‐delivery was associated with shorter stent placement time in the multiple regression analysis, with a stent placement time of 18 and 23 min in LC slim‐delivery and LCD groups, respectively. The early adverse event (AE) rate of LC slim‐delivery was 10%, with no cholangitis or cholecystitis as compared to 23% in the LCD group. Recurrent biliary obstruction (RBO) rates and time to RBO were comparable between the two groups: 35% and 44%, and 8.5 and 8.0 months in LC slim‐delivery and LCD groups, respectively. The major cause of RBO was tumor ingrowth (82%) in the LC slim‐delivery group and sludge (43%) and ingrowth (48%) in LCD group.ConclusionStent‐in‐stent methods using LC slim‐delivery shortened stent placement time with low early AE rates and comparable time to RBO in patients with HMBO.