Clinical Evaluation of LeGoo™ Internal Vessel Occluder Versus Traditional Vessel Loops

The purpose of this study is to evaluate the clinical efficacy of LeGoo™ as compared to a traditional vessel loop. LeGoo is a device that is intended to be used during surgical procedures to temporarily occlude blood vessels while forming an anastomosis. LeGoo™ will be evaluated in subjects undergoing off-pump coronary artery by-pass (OPCAB) surgery. This is a prospective, randomized trial with a 30-day follow-up period. Half of the eligible patients will be randomized to the experimental group (LeGoo™); and the other half to the control group (standard vessel loops). LeGoo™ is polymer-based device which is comprised of a non-toxic and biocompatible gel that exists as a liquid at low temperatures and rapidly transitions to a solid at body temperature, forming a plug that can occlude blood vessels. LeGoo™ is injected into a blood vessel that is intended to be occluded, where it stays in a "plug" form for several minutes allowing the surgeon to work in a bloodless field. The gel dissolves with time (spontaneously) or can be reversed back to liquid instantly by cooling the site with ice or irrigating with cold saline. Once dissolved below a minimum concentration, the polymer can never re-solidify. The primary research hypothesis is that surgeons will obtain a bloodless surgical field and achieve satisfactory hemostasis in a larger proportion of anastomoses using LeGoo™ than using a conventional temporary hemostasis technique. Satisfactory hemostasis is defined by the surgeon who will quantitate his/her observation about the quality of the surgical field using the following scoring system: 1. \- Excellent hemostasis (no bleeding) 2. \- Minimal bleeding (bleeding does not interfere with suturing) 3. \- Modest bleeding (required intermittent use of another device to control bleeding at the site of the anastomosis) 4. \- Copious bleeding (required continuous use of another device) "Excellent hemostasis" and "minimal bleeding" are considered "satisfactory hemostasis." Satisfactory hemostasis will constitute a treatment success for the purpose of evaluating the primary efficacy of LeGoo. The primary endpoint is the proportion of anastomoses in which satisfactory hemostasis is achieved.