Biliary drainage by using stents without a central lumen: A pilot study

Background: Despite several attempts to make the conventional tubular stents with a central lumen for flow less susceptible to a biofilm buildup and thereby prevent clogging, this goal has remained elusive. We hypothesized that the creation of pathways for fluid flow around the stent instead of through it would avoid this problem. The aim of our study was to report the development and the evaluation of a novel lumen-less stent. Methods: By using a software computer modeling, a 10F "winged" stent was designed. A pilot feasibility study was performed by using a prototype of this stent for endoscopic biliary drainage in 5 patients with malignant biliary obstruction. Observations: Modeling data revealed that the winged stent offers a larger surface area for flow, higher velocity of flow, and increased flow rates compared with the conventional tubular stent. In the clinical trial, there was a significant decrease of serum bilirubin after the placement of this stent (serum bilirubin before and 2 weeks after stent placement, 14.94 ± 5.7 mg/dL vs. 2.86 ± 1.4 [p < 0.004]), accompanied by radiologic evidence of decompression of the biliary system. Conclusions: We have shown that it is possible to provide adequate biliary drainage by using a stent without a lumen. Such a design may have potential clinical advantages over existing designs.