Magnetic pancreaticobiliary stents and retrieval system: obviating the need for repeat endoscopy (with video).
BACKGROUND
Plastic stents are routinely placed in the pancreaticobiliary system to facilitate drainage. A second endoscopy is often required for stent removal. We have developed magnetic pancreaticobiliary stents that can be removed by using an external hand-held magnet, thereby obviating the need for a second endoscopy.


OBJECTIVE
To develop and test magnetic pancreaticobiliary stents and retrieval system in ex-vivo and in-vivo porcine models.


METHODS
Animal laboratory.


METHODS
Benchtop and animal study.


METHODS
5 pigs.


METHODS
Design: Computer simulations determined both the optimal design of cylindrical magnets attached to the distal aspect of existing plastic stents and the optimal design of the external hand-held magnet. Benchtop ex-vivo experiments measured magnetic force to validate the design. In-vivo analysis: In 5 Yorkshire pigs, magnetic stents were deployed into the common bile duct by using a conventional duodenoscope. An external hand-held magnet was applied for stent removal. Stent insertion and removal times were recorded.


METHODS
Technical feasibility.


RESULTS
Magnetic stents of varying lengths and calibers were successfully created. In ex-vivo testing, the capture distance was 10.0 cm. During in-vivo testing, the magnetic stents were inserted and removed easily. The mean insertion and removal times were 3.2 minutes and 33 seconds, respectively.


CONCLUSIONS
Animal study, small numbers.


CONCLUSIONS
Magnetic pancreaticobiliary stents and associated retrieval system were successfully designed and tested in the acute porcine model. An external, noninvasive means of stent removal potentially obviates the need for a second endoscopy, which could represent a major gain both for patients and in health care savings.
Division of Gastroenterology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Marvin
M
Ryou
Padraig
P
Cantillon-Murphy
Sohail N
SN
Shaikh
Dan
D
Azagury
Michele B
MB
Ryan
Jeffrey H
JH
Lang
Christopher C
CC
Thompson
D000818:Animals; D003135:Common Bile Duct; D020878:Device Removal / Q000379:methods*; D005240:Feasibility Studies; D059346:Magnets; D019919:Prosthesis Implantation; D015607:Stents; D013552:Swine; D013997:Time Factors