Laser assisted vascular welding with real time temperature control.
OBJECTIVE
Previous studies in laser assisted vascular welding have been limited by the lack of a reliable end point for tissue fusion. As a means of improving the reproductibility of laser assisted repairs, a system incorporating real time temperature monitoring and closed loop feedback was used.


METHODS
The system consisted of a direct view infrared thermometer for monitoring the laser heated spot, a 1.9 microns diode laser, and a microprocessor for data acquisition and feedback control of the laser power to maintain a constant tissue temperature. Rat aortas were welded under constant surface temperature conditions.


RESULTS
In vivo temperature stability of +/- 2 degrees C was achieved over a temperature range of 70-90 degrees C pertinent to welding small vessels. When welds were completed using the feedback system to maintain the tissue temperature at 80 degrees C, the acute success rate was 100% and the burst pressure was 290 +/- 70 mmHg.


CONCLUSIONS
These studies demonstrate that the use of real time monitoring and feedback control results in improved consistency for vascular tissue welding.
Stewart
R B
RB
ABIOMED, Inc., Danvers, Massachusetts 01923, USA.
Benbrahim
A
A
LaMuraglia
G M
GM
Rosenberg
M
M
L'Italien
G J
GJ
Abbott
W M
WM
Kung
R T
RT
D000714:Anastomosis, Surgical; D000818:Animals; D001012:Aorta, Abdominal / Q000503:physiopathology / Q000601:surgery*; D001831:Body Temperature; D004582:Electronics, Medical / Q000295:instrumentation; D004867:Equipment Design; D005246:Feedback; D005263:Femoral Artery / Q000503:physiopathology / Q000601:surgery; D007259:Infrared Rays; D017075:Laser Coagulation / Q000295:instrumentation; D008838:Microcomputers; D016343:Monitoring, Intraoperative / Q000295:instrumentation; D011312:Pressure; D051381:Rats; D011916:Rats, Inbred F344; D015203:Reproducibility of Results; D013696:Temperature; D013821:Thermometers