title: Laser assisted vascular welding with real time temperature control.
abstract: 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.
authors.affiliation: ABIOMED, Inc., Danvers, Massachusetts 01923, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Stewart
authors.forename: A
authors.initials: A
authors.lastname: Benbrahim
authors.forename: G M
authors.initials: GM
authors.lastname: LaMuraglia
authors.forename: M
authors.initials: M
authors.lastname: Rosenberg
authors.forename: G J
authors.initials: GJ
authors.lastname: L'Italien
authors.forename: W M
authors.initials: WM
authors.lastname: Abbott
authors.forename: R T
authors.initials: RT
authors.lastname: Kung
mesh_terms: 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