Sutureless coronary artery bypass with biologic glued anastomoses: Preliminary in vivo and in vitro results

Objective: As heart surgery becomes increasingly focused on minimally invas ive techniques, it has become apparent that conventional techniques of anas tomosis will need to be severely altered or abandoned. Toward that end, we developed and tested in vitro and in vivo coronary artery bypass graft anas tomoses using a biologic glue formulated from bovine albumin and glutaralde hyde. We used a double-balloon catheter as a temporary internal stent to cr eate and seal the anastomosis during gluing. Methods: Initially, anastomoses were made between cryopreserved human saphe nous vein segments and coronary arteries in vitro on 12 intact bovine heart s. A total of 42 anastomoses were created with the catheter system introduc ed into the distal end of the graft, exiting the back wall, and entering th e anterior wall of the coronary artery. Two balloons (one in the graft and one in the coronary artery) held the anastomosis stable while the biologic glue was applied externally and allowed to set for 2 minutes. The balloon c atheter was then removed from the end of the graft simulating a side-to-sid e internal thoracic artery anastomosis. After the graft had been flushed to assure distal end patency, the open end of the graft was dipped, turning t he anastomosis into an end-to-side graft. A pressure transducer was then at tached to the graft and saline solution forcefully infused. Results: All grafts easily held a pressure of 300 mm Hg; 10 grafts were tes ted up to 560 mm Hg without leaks. Distal and proximal coronary artery pate ncy was checked by examining flow out of the coronary ostia and by cutting arteries distal to the grafts. All anastomoses were patent on being opened and no glue was seen intraluminally, Subsequently, 3 anastomoses of the lef t internal thoracic artery to the left anterior descending artery have been constructed in goats, with autopsies at 24 hours, 10 months, and 1 year re vealing patent anastomoses. Conclusion: A biologic glue and catheter system has been developed that all ows a coronary anastomosis with a high bursting strength to be performed. W hen the system has been further developed and tested, truly minimally invas ive heart surgery may be possible.