A Magnetic Retrieval System for Stents in the Pancreaticobiliary Tree

Clinical endoscopic intervention of the pancreaticobiliary tree [endoscopic retrograde cholangiopancreatography (ERCP)] often concludes with the insertion of a temporary plastic stent to reduce the risk of post-ERCP complications by promoting continued flow of bile and pancreatic fluids. This stent...

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Bibliographic Details
Main Authors: Cantillon-Murphy, Padraig, Ryou, Marvin, Shaikh, Sohail N., Azagury, Dan, Ryan, Michele, Thompson, Christopher C., Lang, Jeffrey H.
Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Format: Article
Language:en_US
Published: Institute of Electrical and Electronics Engineers 2011
Online Access:http://hdl.handle.net/1721.1/67500
https://orcid.org/0000-0002-5765-4369
https://orcid.org/0000-0001-6679-2889
Description
Summary:Clinical endoscopic intervention of the pancreaticobiliary tree [endoscopic retrograde cholangiopancreatography (ERCP)] often concludes with the insertion of a temporary plastic stent to reduce the risk of post-ERCP complications by promoting continued flow of bile and pancreatic fluids. This stent is later removed once the patient has fully recovered, but today this necessitates a second endoscopic intervention. The final goal of this work is to obviate the second intervention. This is to be achieved by adding a magnetic ring to the stent such that the stent is removed using a hand-held magnet, held in a suitable position ex vivo . This paper details the design, optimization, and both ex vivo and in vivo testing of the magnetized stent and hand-held magnet, which has been accomplished to date. The optimized design for the hand-held magnet and the modified stent with a magnetic attachment performs in line with simulated expectations, and successful retrieval is achieved in the porcine ex vivo setting at 9-10 cm separation. This is comparable to the mean target capture distance of 10 cm between the entry point to the biliary system and the closest cutaneous surface, determined from random review of clinical fluoroscopies in ten human patients. Subsequently, the system was successfully tested in vivo in the acute porcine model, where retrieval at an estimated separation of 5-6 cm was captured on endoscopic video. These initial results indicate that the system may represent a promising approach for the elimination of a second endoscopic procedures following placement of pancreatic and biliary stents.