Evaluation of a novel 2 mm internal diameter stainless steel saphenous vein to coronary artery connector: Laboratory studies of on-pump and off-pump revascularization

Objective: A second generation, 'easy-load', 2 mm internal diameter (ID), stainless steel, distal anastomotic device has been developed, and design improvements facilitate rapid connector loading with minimal magnification. The reduced size should allow application to most distal coronary vessels currently grafted. This technology may be useful in off-pump and minimally invasive surgical approaches to coronary revascularization. Methods: Two distinct models were used to evaluate the distal connector. In the first model, a single saphenous vein graft (SVG)-to-LAD procedure (n=18) was used to evaluate long-term patency of the 2 mm ID, stainless steel, distal connector in a chronic canine model. Cardiopulmonary bypass was initiated through an anterolateral thoracotomy. Aortosaphenous vein anastomoses were created using suture. In the second model, an acute off-pump feasibility study of SVG-to-LAD bypass fashioned with both proximal and distal connectors (n=15) was conducted. Aortosaphenous vein anastomoses were performed using a FDA approved vascular connector. Device loading and deployment times, graft blood flow following native LAD ligation, and device-related complications were compared. In the chronic model, the grafts were examined by angiography and gross and microscopic examination at animal sacrifice. Results: All 33 animals survived the procedures. All grafts were widely patent after a minimum 30 (n=8), 90 (n=5), and 180 days (n=5) in the chronic model. Distal graft loading and deployment times, graft blood flow rates, and device-related complications were similar in both procedures. In the off-pump feasibility study, total grafting time including loading and deployment was 10:54±2:54 min. Conclusions: Sutureless SVG-to-coronary artery bypass is feasible, rapid, and reproducible with on- and off-pump surgical techniques using a 2 mm ID, stainless steel, distal connector. In this model, early graft patency was 100% with either procedure, and grafts performed on-pump were widely patent at 30, 90, and 180 days. Few device-related complications occurred, each easily managed without compromising graft integrity, and the incidence of events was similar whether on- or off-pump techniques were employed. This or similar technologies may become an important addition to the management of coronary artery disease, particularly in off-pump or minimally invasive approaches.