Hiroshi Anai MD, PhD, Presenter: Nothing to Disclose

Yasushi Fukuoka, Abstract Co-Author: Nothing to Disclose

HIROKI ISHIDA, Abstract Co-Author: Nothing to Disclose

Mai Teranishi, Abstract Co-Author: Nothing to Disclose

Toshiyasu Yuba, Abstract Co-Author: Nothing to Disclose

Kimihiko Kichikawa MD, Abstract Co-Author: Nothing to Disclose

Metallic stent for malignant biliary obstruction has an important role in reduction of jaundice and induction of aggressive treatment for advanced biliary or pancreatic cancer such as anticancer agent. However longer survival has been obtained due to chemotherapy and/or radiation therapy after improvement of jaundice by metallic stent, complications associated with metallic stent such as stent obstruction or reflux cholangitis have been encountered and such complications are sometimes critical to worsen quality of life and shorten survival. The main cause of such complications in the patient treated with metallic stent placed across duodenal papilla is formation of bacterial biofilm as a result of the reflux of food residue and debris formation.  

We have developed the newly designed anti-reflux metallic stent (ARMS). The purpose of this in vitro study was to evaluate antegrade and retrograde flow of some various size of this stent and to determine the appropriate one. This ARMS has fully covered by silicon material and has biceps valve at the duodenal side. We prepared six types of ARMS (the diameter(mm)/ the length of the valve(mm), A;10/8, B;10/5, C;10/2, D;8/8, E;8/5, F8/2). The length of each type of ARMS was 5cm. Each ARMS was set at the exit of the water tank with antegrade placement to measure the volume of the antegrade flow and next also set with retrograde placement to measure the flow resistance under various pressure (0.2, 0.5, 1, 2kPa). We evaluated using with saline and glycerin solution (60 cP) which has similar viscosity to human bile.  

The flow rate of antegrade ARMS placement showed highest flow rate with each condition in stent B (stent diameter; 10mm, valve length; 5mm). (Figure) The flow of retrograde ARMS placement did not show any reflux in each ARMS typeunder all pressure.  

One type of our developed newly designed ARMS showed good flow at antegrade fashion and no reflux at retrograde fashion. It should be evaluated at clinical use.

Ideal anti-reflux metallic stent will prevent duodeno-biliary reflux and biliary drainage then can prolong the survival. So this in vitro study plays an important role in this field.

Anai, H, Fukuoka, Y, ISHIDA, H, Teranishi, M, Yuba, T, Kichikawa, K, In vitro Study of the Newly Designed Antireflux Metallic Stent for Dstal Biliary Obstruction.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011753.html