In vivo argon laser vascular welding using thermal feedback: open and closed loop patency and collagen crosslinking
An in vivo study of vascular welding with a fiber-delivered argon laser was conducted using a canine model. Longitudinal arteriotomies and venotomies were treated on femoral vein and artery. Laser energy was delivered to the vessel wall via a 400 {micro}m optical fiber. The surface temperature at the center of the laser spot was monitored in real time using a hollow glass optical fiber-based two-color infrared thermometer. The surface temperature was limited by either a room-temperature saline drip or direct feedback control of the laser using a mechanical shutter to alternately pass and block the laser. Acute patency was evaluated either visually (leak/no leak) or by in vivo burst pressure measurements. Biochemical assays were performed to investigate the possible laser-induced formation or destruction of enzymatically mediated covalent crosslinks between collagen molecules. Viable welds were created both with and without the use of feedback control. Tissues maintained at 50 C using feedback control had an elevated crosslink count compared to controls, while those irradiated without feedback control experienced a decrease. Differences between the volumetric heating associated with open and closed loop protocols may account for the different effects on collagen crosslinks. Covalent mechanisms may play a role in argon laser vascular fusion.
- Sponsoring Organization:
- (US)
- DOE Contract Number:
- W-7405-Eng-48
- OSTI ID:
- 16370
- Report Number(s):
- UCRL-JC-126839; CONF-970231*-; ON: DE98050988; TRN: US200305%%68
- Resource Relation:
- Conference: Conference title not supplied, Conference location not supplied, Conference dates not supplied; Other Information: Supercedes report DE98050988; PBD: 28 Feb 97; PBD: 28 Feb 1997
- Country of Publication:
- United States
- Language:
- English
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