Functional evaluation of an artificial anal sphincter using shape memory alloys.
This article describes an implantable artificial anal sphincter using shape memory alloys and its in vivo assessment in porcine models. The new design was developed as a low invasive prosthesis with a simple structure to solve the problem of severe fecal incontinence in patients with hypoplastic sphincters or without anal sphincters and especially for ostomates. The artificial anal sphincter consists of two shape memory alloy (SMA) plates as the main functional parts to perform two basic functions when the SMA artificial sphincter is fitted around intestines (i.e., an occlusion at body temperature and an opening function on heating). Our previous assessments with short-term animal experiments revealed promising properties with the occlusion function of the device, although some complications, such as overpressure induced ischemia, heat burn, and infections, remained. This article addresses the concerns related to the practical use of the device, the power supplement to drive the actuator, and overheating protection of the device inside bodies. Results of chronic animal experiments of up to 4 weeks suggested great potential for the improved device.
Luo
Yun
Y
Institute of Fluid Science, Tohoku University Biomedical Engineering Research Organization, Seiryo, Aoba-ku, Sendai, Japan. luo@tubero.tohoku.ac.jp
Takagi
Toshiyuki
T
Okuyama
Takeshi
T
Amae
Shintaro
S
Wada
Motoshi
M
Nishi
Kotaro
K
Kamiyama
Takamichi
T
Yambe
Tomoyuki
T
Matsuki
Hidetoshi
H
D000497:Alloys; D001003:Anal Canal; D000818:Animals; D001187:Artificial Organs / Q000592:standards; D004735:Energy Transfer; D004867:Equipment Design; D006358:Hot Temperature; D020007:Implants, Experimental / Q000592:standards; D013552:Swine
D000497:Alloys