<title>Preliminary stress/strain analysis of laser-soldered and -sutured vascular tissue</title>

Abstract

Stress-strain profiles of welded tissue provide additional means of analysing and comparing laser soldering to alternative anastoinosing techniques. Three groups were created in a rabbit model: (1) nonincised control aortic tissue, (2) longitudinal aortotomies repaired with a 808 nm diodelaser (power density 4.8 watts/cm2) after topical application of fibrinogen mixed with indocyanine green dye (peak absorption 805 nm) , and (3) aortotomies repaired with 6-0 polypropylene suture in a running fashion. The rabbits were sacrificed on 0,l,7,and 28 postoperative days and the fresh aortic specimens were strained until disruption in order to produce a stress-strain profile graph. No significant differences were noted between sutured and bonded aorta at any time interval. Nonincised (which served as a control) aortic tissuewithstood significantly higher stress (p<.05) than both sutured and bonded groups at the time of creation. By seven days after operation, no significant differences were noted between any of the three groups. The only significant difference in modulus (stretchability) identified the sutured aorta to be more rigid than the nonincised group (p<.05). Both sutured and laser bonded anastoinoses are weaker than control aorta initially; however, after an early critical period, both treatments achieve the strength of control aorta. By one nionth post-operatively, sutured anastomoses have the disadvantage of creating a less distensible anastomosis.