The second-generation aortic connector: six months' angiographic follow-up.

PURPOSE: Recently, new mechanical anastomotic devices have been developed. Initial results appear to be equivalent to those obtained with suture. The aim of the study was to evaluate the 6-month angiographic patency and clinical results with the St. Jude Medical second-generation aortic connector for proximal aortosaphenous graft anastomosis. DESCRIPTION: From September 2002 to June 2003, 45 connectors were implanted in 39 patients. Thirty-three patients with 36 connectors underwent 6-month angiographic and clinical follow-up. EVALUATION: One connector had an early occlusion and 2 connectors and 1 vein graft were occluded at 6-month angiography, for a patency rate of 88.9% (32 of 36). No device-related complications were detected at 6-month follow-up. CONCLUSIONS: The second-generation aortic connector is safe and easy to use. Preliminary results show no device-related complications and a satisfactory 6-month angiographic patency.

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.

Gene transfer to coronary artery bypass conduits.

BACKGROUND: Gene therapy is a rational approach to prevention of stenosis in saphenous vein grafts used as conduits for coronary artery bypass grafting. To explore this possibility we developed methods for adenoviral-mediated gene transfer to canine saphenous veins. METHODS: During a single procedure, autogenous canine saphenous vein segments were transduced ex vivo and used as coronary artery bypass grafts. The proximal end of each vein was ligated, adenovirus containing the Escherichia coli beta-galactosidase gene (Ad.CMVLacZ) was delivered at titers of 2.5 x 10(9) or 5 x 10(9) plaque-forming units (pfu)/mL to the lumen through a distal heparin lock, and the segment was immersed in the viral solution for 1 hour at 37 degrees C. Control segments were exposed to diluent alone in an identical manner. Aortocoronary anastomoses were made using cardiopulmonary bypass. Transgene expression was assessed qualitatively and quantitatively after 3 days. RESULTS: Beta-galactosidase levels showed a dose-dependent increase: 0.00 +/- 0.00 ng/mg total protein for controls; 5.60 +/- 2.27 ng/mg total protein for a viral titer of 2.5 x 10(9) pfu/mL and 11.97 +/- 6.14 ng/mg for 5 x 10(9) pfu/mL. The two dosage groups differed significantly from each other (p = 0.035) and from controls (p = 0.003). X-gal staining demonstrated mostly endothelial and scattered adventitial transgene expression. CONCLUSIONS: Transgene expression after ex vivo gene transfer into saphenous vein grafts in a canine coronary artery bypass model indicates that this method may be useful for delivery of therapeutic genes to prevent or retard vein graft arteriosclerosis.

Two generations of the St. Jude Medical ATG coronary connector systems for coronary artery anastomoses in coronary artery bypass grafting.

BACKGROUND: In the past, coronary anastomoses have been performed using running and, occasionally, interrupted non-resorbable sutures. Recently, special interest has developed in mechanical anastomotic devices to facilitate minimal invasive techniques or limited access surgery. The experience with two series of patients undergoing coronary artery bypass grafting (CABG) using the St. Jude Medical ATG coronary connector systems (investigational stainless steel device, not yet commercially available) for vein-to-coronary artery anastomoses is reported here. METHODS: Between November 2000 and April 2002, we evaluated two generations of distal coronary connector systems in 19 patients who were scheduled for multivessel CABG. One vein graft-to-coronary artery anastomosis per patient was performed with a stainless steel mechanical connector, in an ongoing investigational study. Although these two generations of the St. Jude Medical ATG coronary connectors have the same underlying construction, somewhat cumbersome loading of the first-generation system led to simplification of the second-generation system, which is currently evaluated. RESULTS: With the first generation of distal connector, hemostasis was instantaneous in all cases, and all anastomoses were patent at the end of the procedure. However, retrograde flow to the native coronary artery was restricted in 1 patient. The connector was removed, and the anastomosis was performed with a running suture at the same site. Three-month angiography or magnetic resonance imaging angiography was available in 11 patients with 10 patent connector grafts. With the second-generation connectors one of five had to be removed because of leakage, and the anastomosis could be sutured at the same site. The other four connector anastomoses were patent and hemostatic at the end of the procedure. CONCLUSIONS: The St. Jude Medical ATG coronary connector system is an effective device for sutureless vein graft to coronary artery anastomoses in CABG. The second-generation system presents a further development eliminating some drawbacks of the first generation such as cumbersome, time-consuming loading as well as suitability for smaller coronary arteries. These connectors allow construction of geometrically round anastomoses and theoretically may also be suitable for sequential anastomoses. After tremendous research and development efforts, an optimized mechanical connection system for small vessel anastomoses has been introduced into clinical investigation. This represents a major step in the era of sutureless vascular connections in cardiac surgery.

First clinical results with a new mechanical connector for distal coronary artery anastomoses in CABG.

BACKGROUND: Coronary anastomoses are currently primarily carried out with the use of running nonabsorbable sutures. Recently, a renewed interest has developed for facilitated mechanical anastomotic devices especially for minimal invasive techniques or limited access surgery. The initial experience with the first successful creation of mechanical vein-to-coronary artery anastomoses in humans is reported. METHODS AND RESULTS: Between November 2000 and June 2001, 14 patients scheduled for multivessel coronary artery bypass grafting (CABG) procedure were investigated. One vein graft-to-coronary artery anastomosis per patient was performed with the St. Jude Medical ATG Symmetry coronary connector system (stainless steel investigational device, not yet commercially available). We evaluated the overall performance of the device. Intraoperative flow measurements of the grafts using transit time methods were measured. A postoperative angiographic control was performed immediately after the procedure in all patients. Hemostasis was instantaneous in all cases and all anastomoses (mechanical n=14, sutured n=40) were patent. Mean intraoperative flow measurements for the mechanical anastomosed vein grafts was 75+/-25 mL/min. Three month angiogram or MRI angiography is available to date in 11 patients. Ten connector grafts were patent and 1 was occluded. There were no cardiac-related adverse events or return of angina; exercise tolerance tests and stress electrocardiograms were normal in all patients. CONCLUSIONS: The St. Jude Medical ATG Symmetry coronary connector system is a new device for sutureless distal vein graft-to-coronary artery anastomoses in CABG. This system allows the construction of geometrically perfect anastomoses. This technology represents a further step in a new era of sutureless anastomoses in cardiac surgery.

The St Jude Medical symmetry aortic connector system for proximal vein graft anastomoses in coronary artery bypass grafting.

OBJECTIVES: A new device designed to create proximal vein graft anastomoses to the aorta in coronary artery bypass grafting was recently developed by the St Jude Medical Anastomotic Technology Group (Minneapolis, Minn). This new anastomosis system consists of a nickel-titanium (nitinol) connector, an aortic cutter, and a delivery device. METHODS: The loading of the vein on the aortic connector and its delivery to the aorta are described. In 43 consecutive patients (mean age 68 +/- 10 years, age range 33-91 years), 65 proximal vein graft anastomoses were performed with the new system. Intraoperative flow rates were assessed for all grafts according to the transit time principle. RESULTS: All connector anastomoses were performed without the use of any aortic clamp. Times to complete these mechanical anastomoses were less than 10 seconds in all cases. Hemostasis was instantaneous in all cases, with only 3 system failures. These connectors were easily removed so that the anastomoses could be performed with standard suturing technique through the same aortotomy without complications. All vein grafts were patent at the end of the procedure, and there were no intraoperative or postoperative complications related to the device. CONCLUSIONS: The aortic connector system was easy to handle and allowed quick creation of reliable, reproducible, and uniform anastomoses. In addition, anastomoses could be done without any clamping of the aorta, which is especially attractive for off-pump procedures, because aortic manipulation and therefore the risks of embolism and aortic dissection would be further minimized. In on-pump cases this technique would facilitate the single-clamp technique, again minimizing aortic manipulation.

An experimental model of saphenous vein-to-coronary artery anastomosis with the St. Jude Medical stainless steel connector.

BACKGROUND: A new stainless steel anastomosis device developed by St. Jude Medical Cardiovascular Group was studied in a canine model. METHODS: In 12 dogs, coronary saphenous vein grafts were made to the left anterior descending coronary artery and to the circumflex coronary artery; one anastomosis was completed with the St. Jude Medical stainless steel connector device, and the other with conventional suturing. A 30-day coronary angiogram was performed in surviving animals, and, after sacrifice, anastomoses were measured, examined grossly, and submitted for histologic study. RESULTS: All 12 animals survived the procedure, and 9 survived to sacrifice at 30 days. Comparing the connector grafts and sutured grafts, no significant differences were found between vessel diameters, intraoperative graft flows, graft patency, and histology. The average loading time for the connector was 8.5 minutes (range 4 to 16 minutes). Mean time for the 12 connector anastomoses was 3 minutes (range 2 to 5 minutes) compared with 8.4 minutes for suture (range 4 to 13 minutes). CONCLUSIONS: The side-to-side stainless steel connector anastomotic device produces a secure anastomosis with minimal variability; compared with suture methods, it is expeditious and has comparable 30-day histology and angiographic results. It promises to be an important addition to the surgical armamentarium for the treatment of coronary artery disease.

New Approaches for Vascular Anastomoses.

Increasing interest in minimally invasive cardiac surgical procedures has generated a renewed interest in facilitated methods to create vascular anastomosis. These devices, in order to be viable, must perform equally or better than sutures. An extensive review of the literature was performed on the different ways to create a mechanical vascular anastomosis. The experience of the authors with the development of a family of connectors (The Symmetry Bypass System; St. Jude Medical, Minneapolis, MN) is presented. The Aortic Connector System (St. Jude Medical) has undergone extensive animal testing with 30-, 90-, and 180-day follow-up. Over 250 human implants have been performed successfully. Preliminary animal studies with the stainless steel coronary connector are also presented. The creation of a facilitated mechanical vascular anastomosis should not compromise quality or patency rates, and produce at least the same results as those obtained with standard suturing techniques. These devices dramatically reduce the time to perform an anastomosis and eliminate the need for aortic clamping and cardiopulmonary bypass. These advantages should result in a significant reduction in surgical complications, and may facilitate a move to true endoscopic and/or percutaneous bypass.