Laser and suture anastomosis: Passive compliance and active force production

One carotid from each dog underwent a laser anastomosis and the other carotid an interrupted suture repair. One or eight weeks later (n greater than or equal to 4 dogs/time period); four rings (1 mm in length) containing the laser or suture anastomosis or the normal artery (two/dog) were removed. Using a photoelectric force transducer and lever system, the ring was stretched in increments and passive force measured. At each length, the arterial muscle was stimulated and active force measured. The mean laser and control passive length/tension (L/T) curves were not different (P greater than 0.05), but the suture curve was shifted downward (P less than 0.05). The mean laser and suture active L/T curves were similar at 1 week (greater than 0.05) and lower than the control curve (P less than 0.04). At 8 weeks, the laser-repaired vessels produced an active force similar to control muscle (P greater than 0.05) but the suture repairs could not generate this active force (P less than 0.05). These data suggest that the laser repair and normal artery are more mechanically compatible than the suture repair as studied by this method.