Pressure controlled clamp using shape memory alloy for minimal vessel invasion in blood flow occlusion.
OBJECTIVE
Vessel damage after clamping may affect the success of surgical operations. A new pressure controlled clamp (SMA clamp) was designed using super elastic property of shape memory alloy (SMA) to realize atraumatic vessel occlusion. The ability and biological effect of the SMA clamp to control pressure was investigated in vivo.


METHODS
The loading-displacement curves of the SMA clamps (experimental group) and conventional clamp (control group) by occlusion of pig carotid arteries were evaluated using a clamping-pressure analyzing system. To investigate macroscopically and histologically the vessel damage of the SMA and conventional clamps, pig carotid arteries were stained with Evan's blue and its histological sections were stained with Elastica Massion after clamping for fifteen minutes.


RESULTS
Constant value was shown in the loading-displacement curve of SMA clamp. In the control group, damaged area stained with Evan's blue in the vessel wall showed enlargement with the pressure increasing. Less areas in experimental groups are observed than that in the control group. Histological section in the experimental group showed no obvious except a slight compressive damage in the tunica intima. In the control group, vessel wall showed irreversible damages.


CONCLUSIONS
This experiment indicated that the SMA clamp, which has a unique mechanical property, can be used without vessels damage. This pressure controlled clamp can be a selection in clinical apparatus to improve surgical safety.
Department of Physical Medicine and Rehabilitation, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, Japan. ye.zhang@bme.tohoku.ac.jp
Ye
Y
Zhang
Hiroyasu
H
Kanetaka
Yuya
Y
Sano
Mitsuhiro
M
Kano
Tadaaki
T
Kudo
Takumi
T
Sato
Yoshinaka
Y
Shimizu
D000818:Animals; D002339:Carotid Arteries / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D020212:Carotid Artery Injuries / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D003250:Constriction; D004548:Elasticity; D004867:Equipment Design; D008297:Male; D008422:Materials Testing; D023421:Models, Animal; D009532:Nickel; D011312:Pressure; D012039:Regional Blood Flow; D013525:Surgical Instruments; D013552:Swine; D014025:Titanium; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000295:instrumentation*; D057772:Vascular System Injuries / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*
C040654:titanium nickelide; D009532:Nickel; D014025:Titanium