Numerous studies have shown that the use of proteinic solders during laser-assisted vascular anastomosis (LAVA) and repair (LAVR) can significantly increase welding strength, but these studies combined solder-mediated LAVA/R with the use of stay sutures, thereby defeating its purpose. In an in vitro study, we examined the leaking point pressures (LPPs) and histological damage profile of porcine carotid arteries following albumin solder-mediated CO(2) LAVR without the use of sutures. Longitudinal arteriotomies (9.1+/-0.8 mm in length) were sheathed with 25% liquid bovine serum albumin solder, and LAVR was performed using a micromanipulator-controlled CO(2) laser operating at 170-mW power and 1.25-mm spot size in continuous wave mode. The welding regime consisted of a transversal zigzag pass followed by one or two longitudinal zigzag passes, producing an irradiance of 13.9 W/cm(2) and energies of 10.5 J and 11.3 J per mm weld, respectively. LPPs were measured by the fluid infusion technique, and histological analysis was performed with light, fluorescence, and polarization microscopy. The LPP of the two-pass welds was 351+/-158 mmHg versus 538+/-155 mmHg for the three-pass welds. Thermal damage was confined primarily to the adventitial layers, with limited heat diffusion into the media below the solder around the coaptation interface.