Grants We Funded

Abstract
Photochemical tissue bonding (PTB) is a novel tissue repair technique that combines photosensitizing dyes with visible laser light to produce covalent cross-linking of collagen at a molecular level (nanosutures). Unlike previous laser tissue welding techniques that relied on thermal energy to melt and re-anneal collagen, PTB is non-thermal and avoids the tissue damage inherent with a photo-coagulation approach. PTB has been explored in a variety of tissues including cornea, skin and peripheral nerve, and is ideally suited to surgical techniques requiring a watertight seal and precise coaptation without the introduction of foreign material. Although blood vessel repair stands to benefit from these effects, it has yet to be evaluated with PTB as the repair technique. The current gold standard for vascular anastomosis is primary suture repair, which is both time and labor intensive and technically demanding. Furthermore, repeated handling of the vessel wall can damage the endothelial layer promoting thrombus formation or aneurysm. In contrast, PTB repair requires minimal manipulation and can be accomplished with a light dosage lasting approximately 3-6 minutes. For these reasons, we feel that PTB assisted blood vessel repair could provide favorable results in terms of repair quality and procedure time when compared to primary repair using sutures.

Biography
Dr. Winograd is a reconstructive plastic surgeon at Massachusetts General Hospital. He completed both his general and plastic surgery training at Johns Hopkins Hospital including a two year research fellowship in the Plastic Surgery Research Laboratory. He then went on to do an additional year of fellowship training in Hand and Microsurgery at Washington University in Saint Louis in the Division of Plastic Surgery. His research focus has been the improvement of outcomes following microsurgical repair of peripheral nerve injuries. With grant support from the Plastic Surgery Foundation and ASPS, as well as the Academic Scholar program of the American Association of Plastic Surgeons, he has developed a translational research program which investigates the use of photochemical tissue bonding to decrease scarring at neurorrhaphy sites and better isolate the regenerative environment necessary to promote optimal neural regeneration. He is currently funded by the Department of Defense to further investigate the benefits of this technique combined with large gap peripheral nerve injuries and nerve grafting. Most recently, with the current grant support from PSF, the photochemical tissue bonding is being used to improve microsurgical repair of blood vessels, with the added implementation of a dissolvable glass stent to aid in the technical performance and stabilization of the anastomosis.