Improved laser-assisted vascular tissue fusion using light-activated surgical adhesive in a porcine model

Newly developed light-activated surgical adhesives have been investigated as a substitute to traditional protein solders for vascular tissue fusion without the need for sutures. Porcine carotid arteries (n = 6) and femoral arteries (n = 6) were exposed, and an incision was made in the arterial walls using a 16G needle. The surgical adhesive, composed of a poly(L-lactic-co-glycolic acid) scaffold doped with the traditional protein solder mix of porcine serum albumin and indocyanine green dye, was used to close the incisions in conjunction with an 805 nm diode laser. Blood flow was restored to the vessels immediately after the procedure and the incision sites were checked for patency. The new adhesives were flexible enough to be wrapped around the vessels while their solid nature avoided the problems associated with "runaway" of the less viscous liquid protein solders widely used by researchers. The strength and hemostatic abilities of the new surgical adhesives were evaluated in the context of arterial pressure, persistence of hemostasis and presence of any inflammatory reaction after 3 days. After this evaluation period, the surgical procedure was repeated on the carotid arteries (n = 6) and femoral arteries (n = 6) of three additional animals that had been heparinized prior to surgery to closer approximate the conditions seen in a typical vascular surgical setting. The patency rate of both the unheparinized and heparinized vessels was 100% at 3 days post-operative with evidence of intraluminal thrombosis seen in only one of the repaired vessels. The adhesive technique also compared favorably with a previous study conducted using conventional suture techniques. Repairs formed with the adhesive technique were achieved more rapidly than suturing, and acute leakage was observed less frequently. Finally, the adhesive technique produced better histology than the suture technique, suggesting that it has great promise as an alternative to suturing. These initial results indicate that laser-assisted vascular repair using the new adhesives is safe, easy to perform, and contrary to conventional suturing, provides an immediate leak-free closure. In addition, the flexible and moldable nature of the new adhesives allows them to be tailored to a wide range of tissue geometries, thus greatly improving the clinical applicability of laser-assisted tissue repair.