Tissue Adhesive: Current Uses and Strengths.

Tissue adhesives are increasingly important elements in modern medicine, with rapid development over the past 30 years. They enable the innate wound healing processes to occur through the adhesion of tissue to the tissue on-site or tissue to non-tissue surfaces on-site, thus exhibiting some attractive characteristics in the clinic, such as less traumatic closure and suffering, easy application, no stitches required after surgery, excellent cosmetic results, and localized drug release [1]. These tissue adhesives are extensively used for different tissues, including skin, breast, cardiac, gastrointestinal, head and neck, hepatic, orthopedic, pediatric, thoracic, bone, neurological and vascular surgery [2]. After several decades of intensive research activities, a wide variety of tissue adhesives have been developed to increase the ability of tissue adhesives to meet different clinic requirements. The current clinical tissue adhesives could be divided into three groups: natural tissue adhesives, synthetic and semisynthetic tissue adhesive, and biomimetic tissue adhesives. The advantages of tissue adhesives include easy and rapid use with no follow-ups for removal of any residual components as is the case with sutures or staples. Until now, many tissue adhesives synthetic and semi-synthetic in origin with biomimetic characteristics and good biocompatibility have been developed and applied into clinical setting [3]. However, some challenges in the form of poor mechanical strength, swelling, and low stability limited their further applications in the field [4]. Polyurethanes are polymers formed through poly-addition reactions of isocyanates. The medical use of polyurethane was previously limited due to carcinogenicity and toxicity of intermediate chemicals and catalysts. However, after improvement in biosafety by modifying isocyanates from aromatic to lysine-derived, polyurethane adhesives have been introduced for surgical application. A novel lysine-derived urethane adhesive (TissuGlu® Surgical Adhesive, Cohera Medical, Inc., Pittsburgh, PA) has recently been developed which adheres large tissue flaps to the underlying tissue during surgical procedures. TissuGlu is the only FDA-approved polyurethane adhesive for intracorporeal use and it was studied for large flap surgeries such as abdominoplasty [5]. TissuGlu was utilized on patients undergoing abdominoplastic surgery and the results showed that it effectively binds tissue layers together in comparison to standard surgical closure techniques. Thereby reducing dead spaces where seroma can occur, while it also reduces post-surgery wound drainage [6, 7]. Recently, a long-term evaluation of TissuGlu showed that it can prevent the formation of seroma in a canine abdominoplasty model [8, 9]. This glue is described as resorbable and nontoxic; it forms a strong bond between tissue layers, and it eliminates or reduces fluid accumulation and the need for postsurgical drains. The use of the adhesive may provide an alternative to closed suction drains, reducing patient discomfort and the risks associated with indwelling drains. Although using the drains is routine, it is only moderately effective at reducing rates of seroma formation, as the majority of studies reporting, and will still require invasive procedures in order to manage post-operative fluid complications. Furthermore, drain usage in itself can be associated with unwanted complications such as clogging, infection, or accidental displacement. Importantly, the use of drains is associated with a significant increase in the post-operative pain and hospital stays while also increasing the risk for retrograde bacterial migration and infection. The manuscript entitled “Evaluation of a resorbable lysine-based urethane adhesive for a drain-free closure of the abdominal donor site in a deep inferior epigastric perforator (DIEP) flap breast reconstruction procedure” [5] is an excellent study demonstrating the safety and effectiveness of TissueGlu Surgical Adhesive as a less invasive alternative to surgical drains in the abdominal donor site for autologous breast reconstruction with DIEP flap. This prospective, randomized clinical trial compares the outcomes in patients undergoing large flap surgery using closed suction drains to patients undergoing large tissue flap surgery using the lysine-derived urethane adhesive without drains. The authors showed that the less invasive approach to the abdominal flap fixation, using a resorbable lysine-based urethane adhesive, may allow the elimination of drains at the donor site. This can improve the postoperative patient’s quality of life while reducing drain management and time by the nursing staff. There were other important benefits, such as an early postoperative